X Window System Protocol X Consortium Standard X Version 11, Release 6.7 DRAFT Robert W. Scheifler X Consortium, Inc. X Window System is a trademark of The Open Group. Copyright (C) 1986, 1987, 1988, 1994, 2002 The Open Group Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documenta- tion files (the ``Software''), to deal in the Software with- out restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the fol- lowing conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PUR- POSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. Except as contained in this notice, the name of the Open Group shall not be used in advertising or otherwise to pro- mote the sale, use or other dealings in this Software with- out prior written authorization from the Open Group. Acknowledgments The primary contributers to the X11 protocol are: Dave Carver (Digital HPW) Branko Gerovac (Digital HPW) Jim Gettys (MIT/Project Athena, Digital) Phil Karlton (Digital WSL) Scott McGregor (Digital SSG) Ram Rao (Digital UEG) David Rosenthal (Sun) Dave Winchell (Digital UEG) The implementors of initial server who provided useful input are: Susan Angebranndt (Digital) Raymond Drewry (Digital) Todd Newman (Digital) The invited reviewers who provided useful input are: Andrew Cherenson (Berkeley) Burns Fisher (Digital) Dan Garfinkel (HP) Leo Hourvitz (Next) Brock Krizan (HP) David Laidlaw (Stellar) Dave Mellinger (Interleaf) Ron Newman (MIT) John Ousterhout (Berkeley) Andrew Palay (ITC CMU) Ralph Swick (MIT) Craig Taylor (Sun) Jeffery Vroom (Stellar) Thanks go to Al Mento of Digital's UEG Documentation Group for formatting this document. This document does not attempt to provide the rationale or pragmatics required to fully understand the protocol or to place it in perspective within a complete system. The protocol contains many management mechanisms that are not intended for normal applications. Not all mechanisms are needed to build a particular user interface. It is important to keep in mind that the protocol is intended to provide mechanism, not policy. Robert W. Scheifler X Consortium, Inc. 1. Protocol Formats Request Format Every request contains an 8-bit major opcode and a 16-bit length field expressed in units of four bytes. Every request consists of four bytes of a header (containing the major opcode, the length field, and a data byte) followed by zero or more additional bytes of data. The length field defines the total length of the request, including the header. The length field in a request must equal the mini- mum length required to contain the request. If the speci- fied length is smaller or larger than the required length, an error is generated. Unused bytes in a request are not required to be zero. Major opcodes 128 through 255 are reserved for extensions. Extensions are intended to contain multiple requests, so extension requests typically have an additional minor opcode encoded in the second data byte in the request header. However, the placement and interpreta- tion of this minor opcode and of all other fields in exten- sion requests are not defined by the core protocol. Every request on a given connection is implicitly assigned a sequence number, starting with one, that is used in replies, errors, and events. Reply Format Every reply contains a 32-bit length field expressed in units of four bytes. Every reply consists of 32 bytes fol- lowed by zero or more additional bytes of data, as specified in the length field. Unused bytes within a reply are not guaranteed to be zero. Every reply also contains the least significant 16 bits of the sequence number of the corre- sponding request. Error Format Error reports are 32 bytes long. Every error includes an 8-bit error code. Error codes 128 through 255 are reserved for extensions. Every error also includes the major and minor opcodes of the failed request and the least signifi- cant 16 bits of the sequence number of the request. For the following errors (see section 4), the failing resource ID is also returned: Colormap, Cursor, Drawable, Font, GContext, IDChoice, Pixmap, and Window. For Atom errors, the failing atom is returned. For Value errors, the failing value is returned. Other core errors return no additional data. Unused bytes within an error are not guaranteed to be zero. Event Format Events are 32 bytes long. Unused bytes within an event are not guaranteed to be zero. Every event contains an 8-bit type code. The most significant bit in this code is set if 1 X Protocol X11, Release 6.7 DRAFT the event was generated from a SendEvent request. Event codes 64 through 127 are reserved for extensions, although the core protocol does not define a mechanism for selecting interest in such events. Every core event (with the excep- tion of KeymapNotify) also contains the least significant 16 bits of the sequence number of the last request issued by the client that was (or is currently being) processed by the server. 2. Syntactic Conventions The rest of this document uses the following syntactic con- ventions. o The syntax {...} encloses a set of alternatives. o The syntax [...] encloses a set of structure compo- nents. o In general, TYPEs are in uppercase and AlternativeVal- ues are capitalized. o Requests in section 9 are described in the following format: RequestName arg1: type1 ... argN: typeN -> result1: type1 ... resultM: typeM Errors: kind1, ..., kindK Description. If no -> is present in the description, then the request has no reply (it is asynchronous), although errors may still be reported. If ->+ is used, then one or more replies can be generated for a single request. o Events in section 11 are described in the following format: EventName value1: type1 ... valueN: typeN 2 X Protocol X11, Release 6.7 DRAFT Description. 3. Common Types ------------------------------------------------------------------- Name Value ------------------------------------------------------------------- LISTofFOO A type name of the form LISTofFOO means a counted list of elements of type FOO. The size of the length field may vary (it is not necessarily the same size as a FOO), and in some cases, it may be implicit. It is fully specified in Appendix B. Except where explicitly noted, zero-length lists are legal. BITMASK The types BITMASK and LISTofVALUE are somewhat spe- LISTofVALUE cial. Various requests contain arguments of the form: value-mask: BITMASK value-list: LISTofVALUE These are used to allow the client to specify a subset of a heterogeneous collection of optional arguments. The value-mask specifies which argu- ments are to be provided; each such argument is assigned a unique bit position. The representation of the BITMASK will typically contain more bits than there are defined arguments. The unused bits in the value-mask must be zero (or the server gen- erates a Value error). The value-list contains one value for each bit set to 1 in the mask, from least significant to most significant bit in the mask. Each value is represented with four bytes, but the actual value occupies only the least significant bytes as required. The values of the unused bytes do not matter. OR A type of the form ``T1 or ... or Tn'' means the union of the indicated types. A single-element type is given as the element without enclosing braces. WINDOW 32-bit value (top three bits guaranteed to be zero) PIXMAP 32-bit value (top three bits guaranteed to be zero) CURSOR 32-bit value (top three bits guaranteed to be zero) FONT 32-bit value (top three bits guaranteed to be zero) GCONTEXT 32-bit value (top three bits guaranteed to be zero) COLORMAP 32-bit value (top three bits guaranteed to be zero) DRAWABLE WINDOW or PIXMAP FONTABLE FONT or GCONTEXT ATOM 32-bit value (top three bits guaranteed to be zero) VISUALID 32-bit value (top three bits guaranteed to be zero) VALUE 32-bit quantity (used only in LISTofVALUE) BYTE 8-bit value INT8 8-bit signed integer 3 X Protocol X11, Release 6.7 DRAFT ------------------------------------------------------------------- Name Value ------------------------------------------------------------------- INT16 16-bit signed integer INT32 32-bit signed integer CARD8 8-bit unsigned integer CARD16 16-bit unsigned integer CARD32 32-bit unsigned integer TIMESTAMP CARD32 BITGRAVITY {Forget, Static, NorthWest, North, NorthEast, West, Center, East, SouthWest, South, SouthEast} WINGRAVITY {Unmap, Static, NorthWest, North, NorthEast, West, Center, East, SouthWest, South, SouthEast} BOOL {True, False} EVENT {KeyPress, KeyRelease, OwnerGrabButton, Button- Press, ButtonRelease, EnterWindow, LeaveWindow, Pointer- Motion, PointerMotionHint, Button1Motion, Button2Motion, Button3Motion, Button4Motion, Button5Motion, But- tonMotion, Exposure, VisibilityChange, StructureNotify, ResizeRedirect, SubstructureNotify, SubstructureRedirect, FocusChange, PropertyChange, ColormapChange, KeymapState} POINTEREVENT {ButtonPress, ButtonRelease, EnterWindow, LeaveWin- dow, PointerMotion, PointerMotionHint, Button1Motion, Button2Motion, Button3Motion, Button4Motion, But- ton5Motion, ButtonMotion, KeymapState} DEVICEEVENT {KeyPress, KeyRelease, ButtonPress, ButtonRelease, PointerMotion, Button1Motion, Button2Motion, But- ton3Motion, Button4Motion, Button5Motion, ButtonMotion} KEYSYM 32-bit value (top three bits guaranteed to be zero) KEYCODE CARD8 BUTTON CARD8 KEYMASK {Shift, Lock, Control, Mod1, Mod2, Mod3, Mod4, Mod5} BUTMASK {Button1, Button2, Button3, Button4, Button5} KEYBUTMASK KEYMASK or BUTMASK STRING8 LISTofCARD8 STRING16 LISTofCHAR2B CHAR2B [byte1, byte2: CARD8] POINT [x, y: INT16] RECTANGLE [x, y: INT16, width, height: CARD16] 4 X Protocol X11, Release 6.7 DRAFT ------------------------------------------------------------------- Name Value ------------------------------------------------------------------- ARC [x, y: INT16, width, height: CARD16, angle1, angle2: INT16] HOST [family: {Internet, InternetV6, DECnet, Chaos} address: LISTofBYTE] The [x,y] coordinates of a RECTANGLE specify the upper-left corner. The primary interpretation of large characters in a STRING16 is that they are composed of two bytes used to index a two- dimensional matrix, hence, the use of CHAR2B rather than CARD16. This corresponds to the JIS/ISO method of indexing 2-byte characters. It is expected that most large fonts will be defined with 2-byte matrix indexing. For large fonts constructed with linear indexing, a CHAR2B can be interpreted as a 16-bit number by treating byte1 as the most significant byte. This means that clients should always transmit such 16-bit character values most significant byte first, as the server will never byte-swap CHAR2B quantities. The length, format, and interpretation of a HOST address are specific to the family (see ChangeHosts request). 4. Errors In general, when a request terminates with an error, the request has no side effects (that is, there is no partial execution). The only requests for which this is not true are ChangeWindowAttributes, ChangeGC, PolyText8, PolyText16, FreeColors, StoreColors, and ChangeKeyboardControl. The following error codes result from various requests as follows: ------------------------------------------------------------- Error Description ------------------------------------------------------------- 5 X Protocol X11, Release 6.7 DRAFT ------------------------------------------------------------- Error Description ------------------------------------------------------------- Access An attempt is made to grab a key/button combination already grabbed by another client. An attempt is made to free a colormap entry not allocated by the client or to free an entry in a colormap that was cre- ated with all entries writable. An attempt is made to store into a read- only or an unallocated colormap entry. An attempt is made to modify the access control list from other than the local host (or otherwise authorized client). An attempt is made to select an event type that only one client can select at a time when another client has already selected it. Alloc The server failed to allocate the requested resource. Note that the explicit listing of Alloc errors in request only covers allocation errors at a very coarse level and is not intended to cover all cases of a server running out of allocation space in the middle of service. The semantics when a server runs out of allocation space are left unspecified, but a server may generate an Alloc error on any request for this reason, and clients should be prepared to receive such errors and handle or discard them. Atom A value for an ATOM argument does not name a defined ATOM. Colormap A value for a COLORMAP argument does not name a defined COLORMAP. Cursor A value for a CURSOR argument does not name a defined CURSOR. Drawable A value for a DRAWABLE argument does not name a defined WINDOW or PIXMAP. Font A value for a FONT argument does not name a defined FONT. A value for a FONTABLE argument does not name a defined FONT or a defined GCONTEXT. GContext A value for a GCONTEXT argument does not name a defined GCONTEXT. IDChoice The value chosen for a resource identifier either is not included in the range assigned to the client or is already in use. 6 X Protocol X11, Release 6.7 DRAFT ------------------------------------------------------------- Error Description ------------------------------------------------------------- Implementation The server does not implement some aspect of the request. A server that generates this error for a core request is defi- cient. As such, this error is not listed for any of the requests, but clients should be prepared to receive such errors and handle or discard them. Length The length of a request is shorter or longer than that required to minimally contain the arguments. The length of a request exceeds the maxi- mum length accepted by the server. Match An InputOnly window is used as a DRAWABLE. In a graphics request, the GCONTEXT argu- ment does not have the same root and depth as the destination DRAWABLE argument. Some argument (or pair of arguments) has the correct type and range, but it fails to match in some other way required by the request. Name A font or color of the specified name does not exist. Pixmap A value for a PIXMAP argument does not name a defined PIXMAP. Request The major or minor opcode does not specify a valid request. Value Some numeric value falls outside the range of values accepted by the request. Unless a specific range is specified for an argu- ment, the full range defined by the argu- ment's type is accepted. Any argument defined as a set of alternatives typically can generate this error (due to the encod- ing). Window A value for a WINDOW argument does not name a defined WINDOW. ------------------------------------------------------------- Note The Atom, Colormap, Cursor, Drawable, Font, GCon- text, Pixmap, and Window errors are also used when the argument type is extended by union with a set of fixed alternatives, for example, . 7 X Protocol X11, Release 6.7 DRAFT 5. Keyboards A KEYCODE represents a physical (or logical) key. Keycodes lie in the inclusive range [8,255]. A keycode value carries no intrinsic information, although server implementors may attempt to encode geometry information (for example, matrix) to be interpreted in a server-dependent fashion. The map- ping between keys and keycodes cannot be changed using the protocol. A KEYSYM is an encoding of a symbol on the cap of a key. The set of defined KEYSYMs include the character sets Latin-1, Latin-2, Latin-3, Latin-4, Kana, Arabic, Cyrillic, Greek, Tech, Special, Publish, APL, Hebrew, Thai, and Korean as well as a set of symbols common on keyboards (Return, Help, Tab, and so on). KEYSYMs with the most significant bit (of the 29 bits) set are reserved as vendor-specific. A list of KEYSYMs is associated with each KEYCODE. The list is intended to convey the set of symbols on the correspond- ing key. If the list (ignoring trailing NoSymbol entries) is a single KEYSYM ``K'', then the list is treated as if it were the list ``K NoSymbol K NoSymbol''. If the list (ignoring trailing NoSymbol entries) is a pair of KEYSYMs ``K1 K2'', then the list is treated as if it were the list ``K1 K2 K1 K2''. If the list (ignoring trailing NoSymbol entries) is a triple of KEYSYMs ``K1 K2 K3'', then the list is treated as if it were the list ``K1 K2 K3 NoSymbol''. When an explicit ``void'' element is desired in the list, the value VoidSymbol can be used. The first four elements of the list are split into two groups of KEYSYMs. Group 1 contains the first and second KEYSYMs, Group 2 contains the third and fourth KEYSYMs. Within each group, if the second element of the group is NoSymbol, then the group should be treated as if the second element were the same as the first element, except when the first element is an alphabetic KEYSYM ``K'' for which both lowercase and uppercase forms are defined. In that case, the group should be treated as if the first element were the lowercase form of ``K'' and the second element were the uppercase form of ``K''. The standard rules for obtaining a KEYSYM from a KeyPress event make use of only the Group 1 and Group 2 KEYSYMs; no interpretation of other KEYSYMs in the list is defined. The modifier state determines which group to use. Switching between groups is controlled by the KEYSYM named MODE SWITCH, by attaching that KEYSYM to some KEYCODE and attach- ing that KEYCODE to any one of the modifiers Mod1 through Mod5. This modifier is called the ``group modifier''. For any KEYCODE, Group 1 is used when the group modifier is off, and Group 2 is used when the group modifier is on. 8 X Protocol X11, Release 6.7 DRAFT The Lock modifier is interpreted as CapsLock when the KEYSYM named CAPS LOCK is attached to some KEYCODE and that KEYCODE is attached to the Lock modifier. The Lock modifier is interpreted as ShiftLock when the KEYSYM named SHIFT LOCK is attached to some KEYCODE and that KEYCODE is attached to the Lock modifier. If the Lock modifier could be interpreted as both CapsLock and ShiftLock, the CapsLock interpretation is used. The operation of ``keypad'' keys is controlled by the KEYSYM named NUM LOCK, by attaching that KEYSYM to some KEYCODE and attaching that KEYCODE to any one of the modifiers Mod1 through Mod5. This modifier is called the ``numlock modi- fier''. The standard KEYSYMs with the prefix KEYPAD in their name are called ``keypad'' KEYSYMs; these are KEYSYMS with numeric value in the hexadecimal range #xFF80 to #xFFBD inclusive. In addition, vendor-specific KEYSYMS in the hexadecimal range #x11000000 to #x1100FFFF are also keypad KEYSYMs. Within a group, the choice of KEYSYM is determined by apply- ing the first rule that is satisfied from the following list: o The numlock modifier is on and the second KEYSYM is a keypad KEYSYM. In this case, if the Shift modifier is on, or if the Lock modifier is on and is interpreted as ShiftLock, then the first KEYSYM is used; otherwise, the second KEYSYM is used. o The Shift and Lock modifiers are both off. In this case, the first KEYSYM is used. o The Shift modifier is off, and the Lock modifier is on and is interpreted as CapsLock. In this case, the first KEYSYM is used, but if that KEYSYM is lowercase alphabetic, then the corresponding uppercase KEYSYM is used instead. o The Shift modifier is on, and the Lock modifier is on and is interpreted as CapsLock. In this case, the sec- ond KEYSYM is used, but if that KEYSYM is lowercase alphabetic, then the corresponding uppercase KEYSYM is used instead. o The Shift modifier is on, or the Lock modifier is on and is interpreted as ShiftLock, or both. In this case, the second KEYSYM is used. The mapping between KEYCODEs and KEYSYMs is not used directly by the server; it is merely stored for reading and writing by clients. 9 X Protocol X11, Release 6.7 DRAFT 6. Pointers Buttons are always numbered starting with one. 7. Predefined Atoms Predefined atoms are not strictly necessary and may not be useful in all environments, but they will eliminate many InternAtom requests in most applications. Note that they are predefined only in the sense of having numeric values, not in the sense of having required semantics. The core protocol imposes no semantics on these names, but semantics are specified in other X.Org standards, such as the Inter- Client Communication Conventions Manual and the X Logical Font Description Conventions. The following names have predefined atom values. Note that uppercase and lowercase matter. ARC ITALIC_ANGLE STRING ATOM MAX_SPACE SUBSCRIPT_X BITMAP MIN_SPACE SUBSCRIPT_Y CAP_HEIGHT NORM_SPACE SUPERSCRIPT_X CARDINAL NOTICE SUPERSCRIPT_Y COLORMAP PIXMAP UNDERLINE_POSITION COPYRIGHT POINT UNDERLINE_THICKNESS CURSOR POINT_SIZE VISUALID CUT_BUFFER0 PRIMARY WEIGHT CUT_BUFFER1 QUAD_WIDTH WINDOW CUT_BUFFER2 RECTANGLE WM_CLASS CUT_BUFFER3 RESOLUTION WM_CLIENT_MACHINE CUT_BUFFER4 RESOURCE_MANAGER WM_COMMAND CUT_BUFFER5 RGB_BEST_MAP WM_HINTS CUT_BUFFER6 RGB_BLUE_MAP WM_ICON_NAME CUT_BUFFER7 RGB_COLOR_MAP WM_ICON_SIZE DRAWABLE RGB_DEFAULT_MAP WM_NAME END_SPACE RGB_GRAY_MAP WM_NORMAL_HINTS FAMILY_NAME RGB_GREEN_MAP WM_SIZE_HINTS FONT RGB_RED_MAP WM_TRANSIENT_FOR FONT_NAME SECONDARY WM_ZOOM_HINTS FULL_NAME STRIKEOUT_ASCENT X_HEIGHT INTEGER STRIKEOUT_DESCENT To avoid conflicts with possible future names for which semantics might be imposed (either at the protocol level or in terms of higher level user interface models), names beginning with an underscore should be used for atoms that are private to a particular vendor or organization. To guarantee no conflicts between vendors and organizations, additional prefixes need to be used. However, the protocol does not define the mechanism for choosing such prefixes. For names private to a single application or end user but stored in globally accessible locations, it is suggested 10 X Protocol X11, Release 6.7 DRAFT that two leading underscores be used to avoid conflicts with other names. 8. Connection Setup For remote clients, the X protocol can be built on top of any reliable byte stream. Connection Initiation The client must send an initial byte of data to identify the byte order to be employed. The value of the byte must be octal 102 or 154. The value 102 (ASCII uppercase B) means values are transmitted most significant byte first, and value 154 (ASCII lowercase l) means values are transmitted least significant byte first. Except where explicitly noted in the protocol, all 16-bit and 32-bit quantities sent by the client must be transmitted with this byte order, and all 16-bit and 32-bit quantities returned by the server will be transmitted with this byte order. Following the byte-order byte, the client sends the follow- ing information at connection setup: protocol-major-version: CARD16 protocol-minor-version: CARD16 authorization-protocol-name: STRING8 authorization-protocol-data: STRING8 The version numbers indicate what version of the protocol the client expects the server to implement. The authorization name indicates what authorization (and authentication) protocol the client expects the server to use, and the data is specific to that protocol. Specifica- tion of valid authorization mechanisms is not part of the core X protocol. A server that does not implement the pro- tocol the client expects or that only implements the host- based mechanism may simply ignore this information. If both name and data strings are empty, this is to be interpreted as ``no explicit authorization.'' Server Response The client receives the following information at connection setup: success: {Failed, Success, Authenticate} The client receives the following additional data if the returned success value is Failed, and the connection is not successfully established: 11 X Protocol X11, Release 6.7 DRAFT protocol-major-version: CARD16 protocol-minor-version: CARD16 reason: STRING8 The client receives the following additional data if the returned success value is Authenticate, and further authen- tication negotiation is required: reason: STRING8 The contents of the reason string are specific to the autho- rization protocol in use. The semantics of this authentica- tion negotiation are not constrained, except that the nego- tiation must eventually terminate with a reply from the server containing a success value of Failed or Success. The client receives the following additional data if the returned success value is Success, and the connection is successfully established: protocol-major-version: CARD16 protocol-minor-version: CARD16 vendor: STRING8 release-number: CARD32 resource-id-base, resource-id-mask: CARD32 image-byte-order: {LSBFirst, MSBFirst} bitmap-scanline-unit: {8, 16, 32} bitmap-scanline-pad: {8, 16, 32} bitmap-bit-order: {LeastSignificant, MostSignificant} pixmap-formats: LISTofFORMAT roots: LISTofSCREEN motion-buffer-size: CARD32 maximum-request-length: CARD16 min-keycode, max-keycode: KEYCODE where: FORMAT: [depth: CARD8, bits-per-pixel: {1, 4, 8, 16, 24, 32} scanline-pad: {8, 16, 32}] 12 X Protocol X11, Release 6.7 DRAFT SCREEN: [root: WINDOW width-in-pixels, height-in-pixels: CARD16 width-in-millimeters, height-in-mil- limeters: CARD16 allowed-depths: LISTofDEPTH root-depth: CARD8 root-visual: VISUALID default-colormap: COLORMAP white-pixel, black-pixel: CARD32 min-installed-maps, max-installed-maps: CARD16 backing-stores: {Never, WhenMapped, Always} save-unders: BOOL current-input-masks: SETofEVENT] DEPTH: [depth: CARD8 visuals: LISTofVISUALTYPE] VISUALTYPE: [visual-id: VISUALID class: {StaticGray, StaticColor, True- Color, GrayScale, PseudoColor, DirectColor} red-mask, green-mask, blue-mask: CARD32 bits-per-rgb-value: CARD8 colormap-entries: CARD16] Server Information The information that is global to the server is: The protocol version numbers are an escape hatch in case future revisions of the protocol are necessary. In general, the major version would increment for incompatible changes, and the minor version would increment for small upward com- patible changes. Barring changes, the major version will be 11, and the minor version will be 0. The protocol version numbers returned indicate the protocol the server actually supports. This might not equal the version sent by the client. The server can (but need not) refuse connections from clients that offer a different version than the server supports. A server can (but need not) support more than one version simultaneously. The vendor string gives some identification of the owner of the server implementation. The vendor controls the seman- tics of the release number. The resource-id-mask contains a single contiguous set of bits (at least 18). The client allocates resource IDs for types WINDOW, PIXMAP, CURSOR, FONT, GCONTEXT, and COLORMAP by choosing a value with only some subset of these bits set 13 X Protocol X11, Release 6.7 DRAFT and ORing it with resource-id-base. Only values constructed in this way can be used to name newly created resources over this connection. Resource IDs never have the top three bits set. The client is not restricted to linear or contiguous allocation of resource IDs. Once an ID has been freed, it can be reused. An ID must be unique with respect to the IDs of all other resources, not just other resources of the same type. However, note that the value spaces of resource iden- tifiers, atoms, visualids, and keysyms are distinguished by context, and as such, are not required to be disjoint; for example, a given numeric value might be both a valid window ID, a valid atom, and a valid keysym. Although the server is in general responsible for byte-swap- ping data to match the client, images are always transmitted and received in formats (including byte order) specified by the server. The byte order for images is given by image- byte-order and applies to each scanline unit in XY format (bitmap format) and to each pixel value in Z format. A bitmap is represented in scanline order. Each scanline is padded to a multiple of bits as given by bitmap-scanline- pad. The pad bits are of arbitrary value. The scanline is quantized in multiples of bits as given by bitmap-scanline- unit. The bitmap-scanline-unit is always less than or equal to the bitmap-scanline-pad. Within each unit, the leftmost bit in the bitmap is either the least significant or most significant bit in the unit, as given by bitmap-bit-order. If a pixmap is represented in XY format, each plane is rep- resented as a bitmap, and the planes appear from most sig- nificant to least significant in bit order with no padding between planes. Pixmap-formats contains one entry for each depth value. The entry describes the Z format used to represent images of that depth. An entry for a depth is included if any screen supports that depth, and all screens supporting that depth must support only that Z format for that depth. In Z for- mat, the pixels are in scanline order, left to right within a scanline. The number of bits used to hold each pixel is given by bits-per-pixel. Bits-per-pixel may be larger than strictly required by the depth, in which case the least sig- nificant bits are used to hold the pixmap data, and the val- ues of the unused high-order bits are undefined. When the bits-per-pixel is 4, the order of nibbles in the byte is the same as the image byte-order. When the bits-per-pixel is 1, the format is identical for bitmap format. Each scanline is padded to a multiple of bits as given by scanline-pad. When bits-per-pixel is 1, this will be identical to bitmap-scan- line-pad. How a pointing device roams the screens is up to the server implementation and is transparent to the protocol. No geom- etry is defined among screens. 14 X Protocol X11, Release 6.7 DRAFT The server may retain the recent history of pointer motion and do so to a finer granularity than is reported by Motion- Notify events. The GetMotionEvents request makes such his- tory available. The motion-buffer-size gives the approxi- mate maximum number of elements in the history buffer. Maximum-request-length specifies the maximum length of a request accepted by the server, in 4-byte units. That is, length is the maximum value that can appear in the length field of a request. Requests larger than this maximum gen- erate a Length error, and the server will read and simply discard the entire request. Maximum-request-length will always be at least 4096 (that is, requests of length up to and including 16384 bytes will be accepted by all servers). Min-keycode and max-keycode specify the smallest and largest keycode values transmitted by the server. Min-keycode is never less than 8, and max-keycode is never greater than 255. Not all keycodes in this range are required to have corresponding keys. Screen Information The information that applies per screen is: The allowed-depths specifies what pixmap and window depths are supported. Pixmaps are supported for each depth listed, and windows of that depth are supported if at least one visual type is listed for the depth. A pixmap depth of one is always supported and listed, but windows of depth one might not be supported. A depth of zero is never listed, but zero-depth InputOnly windows are always supported. Root-depth and root-visual specify the depth and visual type of the root window. Width-in-pixels and height-in-pixels specify the size of the root window (which cannot be changed). The class of the root window is always InputOut- put. Width-in-millimeters and height-in-millimeters can be used to determine the physical size and the aspect ratio. The default-colormap is the one initially associated with the root window. Clients with minimal color requirements creating windows of the same depth as the root may want to allocate from this map by default. Black-pixel and white-pixel can be used in implementing a monochrome application. These pixel values are for perma- nently allocated entries in the default-colormap. The actual RGB values may be settable on some screens and, in any case, may not actually be black and white. The names are intended to convey the expected relative intensity of the colors. 15 X Protocol X11, Release 6.7 DRAFT The border of the root window is initially a pixmap filled with the black-pixel. The initial background of the root window is a pixmap filled with some unspecified two-color pattern using black-pixel and white-pixel. Min-installed-maps specifies the number of maps that can be guaranteed to be installed simultaneously (with InstallCol- ormap), regardless of the number of entries allocated in each map. Max-installed-maps specifies the maximum number of maps that might possibly be installed simultaneously, depending on their allocations. Multiple static-visual col- ormaps with identical contents but differing in resource ID should be considered as a single map for the purposes of this number. For the typical case of a single hardware col- ormap, both values will be 1. Backing-stores indicates when the server supports backing stores for this screen, although it may be storage limited in the number of windows it can support at once. If save- unders is True, the server can support the save-under mode in CreateWindow and ChangeWindowAttributes, although again it may be storage limited. The current-input-events is what GetWindowAttributes would return for the all-event-masks for the root window. Visual Information The information that applies per visual-type is: A given visual type might be listed for more than one depth or for more than one screen. For PseudoColor, a pixel value indexes a colormap to produce independent RGB values; the RGB values can be changed dynam- ically. GrayScale is treated in the same way as PseudoColor except which primary drives the screen is undefined; thus, the client should always store the same value for red, green, and blue in colormaps. For DirectColor, a pixel value is decomposed into separate RGB subfields, and each subfield separately indexes the colormap for the correspond- ing value. The RGB values can be changed dynamically. TrueColor is treated in the same way as DirectColor except the colormap has predefined read-only RGB values. These values are server-dependent but provide linear or near-lin- ear increasing ramps in each primary. StaticColor is treated in the same way as PseudoColor except the colormap has predefined read-only RGB values, which are server-depen- dent. StaticGray is treated in the same way as StaticColor except the red, green, and blue values are equal for any single pixel value, resulting in shades of gray. StaticGray with a two-entry colormap can be thought of as monochrome. 16 X Protocol X11, Release 6.7 DRAFT The red-mask, green-mask, and blue-mask are only defined for DirectColor and TrueColor. Each has one contiguous set of bits set to 1 with no intersections. Usually each mask has the same number of bits set to 1. The bits-per-rgb-value specifies the log base 2 of the num- ber of distinct color intensity values (individually) of red, green, and blue. This number need not bear any rela- tion to the number of colormap entries. Actual RGB values are always passed in the protocol within a 16-bit spectrum, with 0 being minimum intensity and 65535 being the maximum intensity. On hardware that provides a linear zero-based intensity ramp, the following relationship exists: hw-intensity = protocol-intensity / (65536 / total-hw-intensities) Colormap entries are indexed from 0. The colormap-entries defines the number of available colormap entries in a newly created colormap. For DirectColor and TrueColor, this will usually be 2 to the power of the maximum number of bits set to 1 in red-mask, green-mask, and blue-mask. 9. Requests __ | CreateWindow wid, parent: WINDOW class: {InputOutput, InputOnly, CopyFromParent} depth: CARD8 visual: VISUALID or CopyFromParent x, y: INT16 width, height, border-width: CARD16 value-mask: BITMASK value-list: LISTofVALUE Errors: Alloc, Colormap, Cursor, IDChoice, Match, Pixmap, |__ Value, Window This request creates an unmapped window and assigns the identifier wid to it. A class of CopyFromParent means the class is taken from the parent. A depth of zero for class InputOutput or Copy- FromParent means the depth is taken from the parent. A visual of CopyFromParent means the visual type is taken from the parent. For class InputOutput, the visual type and depth must be a combination supported for the screen (or a Match error results). The depth need not be the same as the parent, but the parent must not be of class InputOnly (or a 17 X Protocol X11, Release 6.7 DRAFT Match error results). For class InputOnly, the depth must be zero (or a Match error results), and the visual must be one supported for the screen (or a Match error results). However, the parent can have any depth and class. The server essentially acts as if InputOnly windows do not exist for the purposes of graphics requests, exposure pro- cessing, and VisibilityNotify events. An InputOnly window cannot be used as a drawable (as a source or destination for graphics requests). InputOnly and InputOutput windows act identically in other respects-properties, grabs, input con- trol, and so on. The coordinate system has the X axis horizontal and the Y axis vertical with the origin [0, 0] at the upper-left cor- ner. Coordinates are integral, in terms of pixels, and coincide with pixel centers. Each window and pixmap has its own coordinate system. For a window, the origin is inside the border at the inside, upper-left corner. The x and y coordinates for the window are relative to the parent's origin and specify the position of the upper-left outer corner of the window (not the origin). The width and height specify the inside size (not including the border) and must be nonzero (or a Value error results). The border- width for an InputOnly window must be zero (or a Match error results). The window is placed on top in the stacking order with respect to siblings. The value-mask and value-list specify attributes of the win- dow that are to be explicitly initialized. The possible values are: ----------------------------------------------- Attribute Type ----------------------------------------------- background-pixmap PIXMAP or None or Paren- tRelative background-pixel CARD32 border-pixmap PIXMAP or CopyFromParent border-pixel CARD32 bit-gravity BITGRAVITY win-gravity WINGRAVITY backing-store {NotUseful, WhenMapped, Always} backing-planes CARD32 backing-pixel CARD32 save-under BOOL event-mask SETofEVENT do-not-propagate- SETofDEVICEEVENT mask 18 X Protocol X11, Release 6.7 DRAFT ----------------------------------------------- Attribute Type ----------------------------------------------- override-redirect BOOL colormap COLORMAP or CopyFromParent cursor CURSOR or None ----------------------------------------------- The default values when attributes are not explicitly ini- tialized are: ----------------------------------- Attribute Default ----------------------------------- background-pixmap None border-pixmap CopyFromParent bit-gravity Forget win-gravity NorthWest backing-store NotUseful backing-planes all ones backing-pixel zero save-under False event-mask {} (empty set) do-not-propagate- {} (empty set) mask override-redirect False colormap CopyFromParent cursor None ----------------------------------- Only the following attributes are defined for InputOnly win- dows: o win-gravity o event-mask o do-not-propagate-mask o override-redirect o cursor It is a Match error to specify any other attributes for InputOnly windows. If background-pixmap is given, it overrides the default background-pixmap. The background pixmap and the window must have the same root and the same depth (or a Match error results). Any size pixmap can be used, although some sizes may be faster than others. If background None is specified, the window has no defined background. If background 19 X Protocol X11, Release 6.7 DRAFT ParentRelative is specified, the parent's background is used, but the window must have the same depth as the parent (or a Match error results). If the parent has background None, then the window will also have background None. A copy of the parent's background is not made. The parent's background is reexamined each time the window background is required. If background-pixel is given, it overrides the default background-pixmap and any background-pixmap given explicitly, and a pixmap of undefined size filled with back- ground-pixel is used for the background. Range checking is not performed on the background-pixel value; it is simply truncated to the appropriate number of bits. For a Paren- tRelative background, the background tile origin always aligns with the parent's background tile origin. Otherwise, the background tile origin is always the window origin. When no valid contents are available for regions of a window and the regions are either visible or the server is main- taining backing store, the server automatically tiles the regions with the window's background unless the window has a background of None. If the background is None, the previous screen contents from other windows of the same depth as the window are simply left in place if the contents come from the parent of the window or an inferior of the parent; oth- erwise, the initial contents of the exposed regions are undefined. Exposure events are then generated for the regions, even if the background is None. The border tile origin is always the same as the background tile origin. If border-pixmap is given, it overrides the default border-pixmap. The border pixmap and the window must have the same root and the same depth (or a Match error results). Any size pixmap can be used, although some sizes may be faster than others. If CopyFromParent is given, the parent's border pixmap is copied (subsequent changes to the parent's border attribute do not affect the child), but the window must have the same depth as the parent (or a Match error results). The pixmap might be copied by sharing the same pixmap object between the child and parent or by making a complete copy of the pixmap contents. If border-pixel is given, it overrides the default border-pixmap and any bor- der-pixmap given explicitly, and a pixmap of undefined size filled with border-pixel is used for the border. Range checking is not performed on the border-pixel value; it is simply truncated to the appropriate number of bits. Output to a window is always clipped to the inside of the window, so that the border is never affected. The bit-gravity defines which region of the window should be retained if the window is resized, and win-gravity defines how the window should be repositioned if the parent is resized (see ConfigureWindow request). 20 X Protocol X11, Release 6.7 DRAFT A backing-store of WhenMapped advises the server that main- taining contents of obscured regions when the window is mapped would be beneficial. A backing-store of Always advises the server that maintaining contents even when the window is unmapped would be beneficial. In this case, the server may generate an exposure event when the window is created. A value of NotUseful advises the server that main- taining contents is unnecessary, although a server may still choose to maintain contents while the window is mapped. Note that if the server maintains contents, then the server should maintain complete contents not just the region within the parent boundaries, even if the window is larger than its parent. While the server maintains contents, exposure events will not normally be generated, but the server may stop maintaining contents at any time. If save-under is True, the server is advised that when this window is mapped, saving the contents of windows it obscures would be beneficial. When the contents of obscured regions of a window are being maintained, regions obscured by noninferior windows are included in the destination (and source, when the window is the source) of graphics requests, but regions obscured by inferior windows are not included. The backing-planes indicates (with bits set to 1) which bit planes of the window hold dynamic data that must be pre- served in backing-stores and during save-unders. The back- ing-pixel specifies what value to use in planes not covered by backing-planes. The server is free to save only the specified bit planes in the backing-store or save-under and regenerate the remaining planes with the specified pixel value. Any bits beyond the specified depth of the window in these values are simply ignored. The event-mask defines which events the client is interested in for this window (or for some event types, inferiors of the window). The do-not-propagate-mask defines which events should not be propagated to ancestor windows when no client has the event type selected in this window. The override-redirect specifies whether map and configure requests on this window should override a SubstructureRedi- rect on the parent, typically to inform a window manager not to tamper with the window. The colormap specifies the colormap that best reflects the true colors of the window. Servers capable of supporting multiple hardware colormaps may use this information, and window managers may use it for InstallColormap requests. The colormap must have the same visual type and root as the window (or a Match error results). If CopyFromParent is specified, the parent's colormap is copied (subsequent 21 X Protocol X11, Release 6.7 DRAFT changes to the parent's colormap attribute do not affect the child). However, the window must have the same visual type as the parent (or a Match error results), and the parent must not have a colormap of None (or a Match error results). For an explanation of None, see FreeColormap request. The colormap is copied by sharing the colormap object between the child and the parent, not by making a complete copy of the colormap contents. If a cursor is specified, it will be used whenever the pointer is in the window. If None is specified, the par- ent's cursor will be used when the pointer is in the window, and any change in the parent's cursor will cause an immedi- ate change in the displayed cursor. This request generates a CreateNotify event. The background and border pixmaps and the cursor may be freed immediately if no further explicit references to them are to be made. Subsequent drawing into the background or border pixmap has an undefined effect on the window state. The server might or might not make a copy of the pixmap. __ | ChangeWindowAttributes window: WINDOW value-mask: BITMASK value-list: LISTofVALUE Errors: Access, Colormap, Cursor, Match, Pixmap, Value, |__ Window The value-mask and value-list specify which attributes are to be changed. The values and restrictions are the same as for CreateWindow. Setting a new background, whether by background-pixmap or background-pixel, overrides any previous background. Set- ting a new border, whether by border-pixel or border-pixmap, overrides any previous border. Changing the background does not cause the window contents to be changed. Setting the border or changing the back- ground such that the border tile origin changes causes the border to be repainted. Changing the background of a root window to None or ParentRelative restores the default back- ground pixmap. Changing the border of a root window to CopyFromParent restores the default border pixmap. 22 X Protocol X11, Release 6.7 DRAFT Changing the win-gravity does not affect the current posi- tion of the window. Changing the backing-store of an obscured window to When- Mapped or Always or changing the backing-planes, backing- pixel, or save-under of a mapped window may have no immedi- ate effect. Multiple clients can select input on the same window; their event-masks are disjoint. When an event is generated, it will be reported to all interested clients. However, only one client at a time can select for SubstructureRedirect, only one client at a time can select for ResizeRedirect, and only one client at a time can select for ButtonPress. An attempt to violate these restrictions results in an Access error. There is only one do-not-propagate-mask for a window, not one per client. Changing the colormap of a window (by defining a new map, not by changing the contents of the existing map) generates a ColormapNotify event. Changing the colormap of a visible window might have no immediate effect on the screen (see InstallColormap request). Changing the cursor of a root window to None restores the default cursor. The order in which attributes are verified and altered is server-dependent. If an error is generated, a subset of the attributes may have been altered. 23 X Protocol X11, Release 6.7 DRAFT __ | GetWindowAttributes window: WINDOW -> visual: VISUALID class: {InputOutput, InputOnly} bit-gravity: BITGRAVITY win-gravity: WINGRAVITY backing-store: {NotUseful, WhenMapped, Always} backing-planes: CARD32 backing-pixel: CARD32 save-under: BOOL colormap: COLORMAP or None map-is-installed: BOOL map-state: {Unmapped, Unviewable, Viewable} all-event-masks, your-event-mask: SETofEVENT do-not-propagate-mask: SETofDEVICEEVENT override-redirect: BOOL |__ Errors: Window This request returns the current attributes of the window. A window is Unviewable if it is mapped but some ancestor is unmapped. All-event-masks is the inclusive-OR of all event masks selected on the window by clients. Your-event-mask is the event mask selected by the querying client. __ | DestroyWindow window: WINDOW |__ Errors: Window If the argument window is mapped, an UnmapWindow request is performed automatically. The window and all inferiors are then destroyed, and a DestroyNotify event is generated for each window. The ordering of the DestroyNotify events is such that for any given window, DestroyNotify is generated on all inferiors of the window before being generated on the window itself. The ordering among siblings and across sub- hierarchies is not otherwise constrained. Normal exposure processing on formerly obscured windows is performed. If the window is a root window, this request has no effect. 24 X Protocol X11, Release 6.7 DRAFT __ | DestroySubwindows window: WINDOW |__ Errors: Window This request performs a DestroyWindow request on all chil- dren of the window, in bottom-to-top stacking order. __ | ChangeSaveSet window: WINDOW mode: {Insert, Delete} Errors: |__ Match, Value, Window This request adds or removes the specified window from the client's save-set. The window must have been created by some other client (or a Match error results). For further information about the use of the save-set, see section 10. When windows are destroyed, the server automatically removes them from the save-set. __ | ReparentWindow window, parent: WINDOW x, y: INT16 |__ Errors: Match, Window If the window is mapped, an UnmapWindow request is performed automatically first. The window is then removed from its current position in the hierarchy and is inserted as a child of the specified parent. The x and y coordinates are rela- tive to the parent's origin and specify the new position of the upper-left outer corner of the window. The window is placed on top in the stacking order with respect to sib- lings. A ReparentNotify event is then generated. The over- ride-redirect attribute of the window is passed on in this event; a value of True indicates that a window manager should not tamper with this window. Finally, if the window was originally mapped, a MapWindow request is performed automatically. 25 X Protocol X11, Release 6.7 DRAFT Normal exposure processing on formerly obscured windows is performed. The server might not generate exposure events for regions from the initial unmap that are immediately obscured by the final map. A Match error is generated if: o The new parent is not on the same screen as the old parent. o The new parent is the window itself or an inferior of the window. o The new parent is InputOnly, and the window is not. o The window has a ParentRelative background, and the new parent is not the same depth as the window. __ | MapWindow window: WINDOW |__ Errors: Window If the window is already mapped, this request has no effect. If the override-redirect attribute of the window is False and some other client has selected SubstructureRedirect on the parent, then a MapRequest event is generated, but the window remains unmapped. Otherwise, the window is mapped, and a MapNotify event is generated. If the window is now viewable and its contents have been discarded, the window is tiled with its background (if no background is defined, the existing screen contents are not altered), and zero or more exposure events are generated. If a backing-store has been maintained while the window was unmapped, no exposure events are generated. If a backing- store will now be maintained, a full-window exposure is always generated. Otherwise, only visible regions may be reported. Similar tiling and exposure take place for any newly viewable inferiors. 26 X Protocol X11, Release 6.7 DRAFT __ | MapSubwindows window: WINDOW |__ Errors: Window This request performs a MapWindow request on all unmapped children of the window, in top-to-bottom stacking order. __ | UnmapWindow window: WINDOW |__ Errors: Window If the window is already unmapped, this request has no effect. Otherwise, the window is unmapped, and an UnmapNo- tify event is generated. Normal exposure processing on for- merly obscured windows is performed. __ | UnmapSubwindows window: WINDOW |__ Errors: Window This request performs an UnmapWindow request on all mapped children of the window, in bottom-to-top stacking order. __ | ConfigureWindow window: WINDOW value-mask: BITMASK value-list: LISTofVALUE |__ Errors: Match, Value, Window This request changes the configuration of the window. The value-mask and value-list specify which values are to be given. The possible values are: 27 X Protocol X11, Release 6.7 DRAFT ----------------------------------------------- Attribute Type ----------------------------------------------- x INT16 y INT16 width CARD16 height CARD16 border-width CARD16 sibling WINDOW stack-mode {Above, Below, TopIf, BottomIf, Opposite} ----------------------------------------------- The x and y coordinates are relative to the parent's origin and specify the position of the upper-left outer corner of the window. The width and height specify the inside size, not including the border, and must be nonzero (or a Value error results). Those values not specified are taken from the existing geometry of the window. Note that changing just the border-width leaves the outer-left corner of the window in a fixed position but moves the absolute position of the window's origin. It is a Match error to attempt to make the border-width of an InputOnly window nonzero. If the override-redirect attribute of the window is False and some other client has selected SubstructureRedirect on the parent, a ConfigureRequest event is generated, and no further processing is performed. Otherwise, the following is performed: If some other client has selected ResizeRedirect on the win- dow and the inside width or height of the window is being changed, a ResizeRequest event is generated, and the current inside width and height are used instead. Note that the override-redirect attribute of the window has no effect on ResizeRedirect and that SubstructureRedirect on the parent has precedence over ResizeRedirect on the window. The geometry of the window is changed as specified, the win- dow is restacked among siblings, and a ConfigureNotify event is generated if the state of the window actually changes. If the inside width or height of the window has actually changed, then children of the window are affected, according to their win-gravity. Exposure processing is performed on formerly obscured windows (including the window itself and its inferiors if regions of them were obscured but now are not). Exposure processing is also performed on any new regions of the window (as a result of increasing the width or height) and on any regions where window contents are lost. If the inside width or height of a window is not changed but the window is moved or its border is changed, then the 28 X Protocol X11, Release 6.7 DRAFT contents of the window are not lost but move with the win- dow. Changing the inside width or height of the window causes its contents to be moved or lost, depending on the bit-gravity of the window. It also causes children to be reconfigured, depending on their win-gravity. For a change of width and height of W and H, we define the [x, y] pairs as: ----------------------- Direction Deltas ----------------------- NorthWest [0, 0] North [W/2, 0] NorthEast [W, 0] West [0, H/2] Center [W/2, H/2] East [W, H/2] SouthWest [0, H] South [W/2, H] SouthEast [W, H] ----------------------- When a window with one of these bit-gravities is resized, the corresponding pair defines the change in position of each pixel in the window. When a window with one of these win-gravities has its parent window resized, the correspond- ing pair defines the change in position of the window within the parent. This repositioning generates a GravityNotify event. GravityNotify events are generated after the Config- ureNotify event is generated. A gravity of Static indicates that the contents or origin should not move relative to the origin of the root window. If the change in size of the window is coupled with a change in position of [X, Y], then for bit-gravity the change in position of each pixel is [-X, -Y] and for win-gravity the change in position of a child when its parent is so resized is [-X, -Y]. Note that Static gravity still only takes effect when the width or height of the window is changed, not when the window is simply moved. A bit-gravity of Forget indicates that the window contents are always discarded after a size change, even if backing- store or save-under has been requested. The window is tiled with its background (except, if no background is defined, the existing screen contents are not altered) and zero or more exposure events are generated. The contents and borders of inferiors are not affected by their parent's bit-gravity. A server is permitted to ignore the specified bit-gravity and use Forget instead. 29 X Protocol X11, Release 6.7 DRAFT A win-gravity of Unmap is like NorthWest, but the child is also unmapped when the parent is resized, and an UnmapNotify event is generated. UnmapNotify events are generated after the ConfigureNotify event is generated. If a sibling and a stack-mode are specified, the window is restacked as follows: Above The window is placed just above the sibling. Below The window is placed just below the sibling. TopIf If the sibling occludes the window, then the window is placed at the top of the stack. BottomIf If the window occludes the sibling, then the window is placed at the bottom of the stack. Opposite If the sibling occludes the window, then the window is placed at the top of the stack. Oth- erwise, if the window occludes the sibling, then the window is placed at the bottom of the stack. If a stack-mode is specified but no sibling is specified, the window is restacked as follows: Above The window is placed at the top of the stack. Below The window is placed at the bottom of the stack. TopIf If any sibling occludes the window, then the window is placed at the top of the stack. BottomIf If the window occludes any sibling, then the window is placed at the bottom of the stack. Opposite If any sibling occludes the window, then the window is placed at the top of the stack. Oth- erwise, if the window occludes any sibling, then the window is placed at the bottom of the stack. It is a Match error if a sibling is specified without a stack-mode or if the window is not actually a sibling. Note that the computations for BottomIf, TopIf, and Opposite are performed with respect to the window's final geometry (as controlled by the other arguments to the request), not to its initial geometry. Attempts to configure a root window have no effect. 30 X Protocol X11, Release 6.7 DRAFT __ | CirculateWindow window: WINDOW direction: {RaiseLowest, LowerHighest} |__ Errors: Value, Window If some other client has selected SubstructureRedirect on the window, then a CirculateRequest event is generated, and no further processing is performed. Otherwise, the follow- ing is performed, and then a CirculateNotify event is gener- ated if the window is actually restacked. For RaiseLowest, CirculateWindow raises the lowest mapped child (if any) that is occluded by another child to the top of the stack. For LowerHighest, CirculateWindow lowers the highest mapped child (if any) that occludes another child to the bottom of the stack. Exposure processing is performed on formerly obscured windows. __ | GetGeometry drawable: DRAWABLE -> root: WINDOW depth: CARD8 x, y: INT16 width, height, border-width: CARD16 |__ Errors: Drawable This request returns the root and current geometry of the drawable. The depth is the number of bits per pixel for the object. The x, y, and border-width will always be zero for pixmaps. For a window, the x and y coordinates specify the upper-left outer corner of the window relative to its par- ent's origin, and the width and height specify the inside size, not including the border. It is legal to pass an InputOnly window as a drawable to this request. 31 X Protocol X11, Release 6.7 DRAFT __ | QueryTree window: WINDOW -> root: WINDOW parent: WINDOW or None children: LISTofWINDOW |__ Errors: Window This request returns the root, the parent, and the children of the window. The children are listed in bottom-to-top stacking order. __ | InternAtom name: STRING8 only-if-exists: BOOL -> atom: ATOM or None |__ Errors: Alloc, Value This request returns the atom for the given name. If only- if-exists is False, then the atom is created if it does not exist. The string should use the ISO Latin-1 encoding. Uppercase and lowercase matter. The lifetime of an atom is not tied to the interning client. Atoms remain defined until server reset (see section 10). __ | GetAtomName atom: ATOM -> name: STRING8 |__ Errors: Atom This request returns the name for the given atom. 32 X Protocol X11, Release 6.7 DRAFT __ | ChangeProperty window: WINDOW property, type: ATOM format: {8, 16, 32} mode: {Replace, Prepend, Append} data: LISTofINT8 or LISTofINT16 or LISTofINT32 |__ Errors: Alloc, Atom, Match, Value, Window This request alters the property for the specified window. The type is uninterpreted by the server. The format speci- fies whether the data should be viewed as a list of 8-bit, 16-bit, or 32-bit quantities so that the server can cor- rectly byte-swap as necessary. If the mode is Replace, the previous property value is dis- carded. If the mode is Prepend or Append, then the type and format must match the existing property value (or a Match error results). If the property is undefined, it is treated as defined with the correct type and format with zero-length data. For Prepend, the data is tacked on to the beginning of the existing data, and for Append, it is tacked on to the end of the existing data. This request generates a PropertyNotify event on the window. The lifetime of a property is not tied to the storing client. Properties remain until explicitly deleted, until the window is destroyed, or until server reset (see section 10). The maximum size of a property is server-dependent and may vary dynamically. __ | DeleteProperty window: WINDOW property: ATOM |__ Errors: Atom, Window This request deletes the property from the specified window if the property exists and generates a PropertyNotify event on the window unless the property does not exist. 33 X Protocol X11, Release 6.7 DRAFT __ | GetProperty window: WINDOW property: ATOM type: ATOM or AnyPropertyType long-offset, long-length: CARD32 delete: BOOL -> type: ATOM or None format: {0, 8, 16, 32} bytes-after: CARD32 value: LISTofINT8 or LISTofINT16 or LISTofINT32 |__ Errors: Atom, Value, Window If the specified property does not exist for the specified window, then the return type is None, the format and bytes- after are zero, and the value is empty. The delete argument is ignored in this case. If the specified property exists but its type does not match the specified type, then the return type is the actual type of the property, the format is the actual format of the property (never zero), the bytes-after is the length of the property in bytes (even if the format is 16 or 32), and the value is empty. The delete argument is ignored in this case. If the specified property exists and either AnyPropertyType is specified or the speci- fied type matches the actual type of the property, then the return type is the actual type of the property, the format is the actual format of the property (never zero), and the bytes-after and value are as follows, given: N = actual length of the stored property in bytes (even if the format is 16 or 32) I = 4 * long-offset T = N - I L = MINIMUM(T, 4 * long-length) A = N - (I + L) The returned value starts at byte index I in the property (indexing from 0), and its length in bytes is L. However, it is a Value error if long-offset is given such that L is negative. The value of bytes-after is A, giving the number of trailing unread bytes in the stored property. If delete is True and the bytes-after is zero, the property is also deleted from the window, and a PropertyNotify event is gen- erated on the window. 34 X Protocol X11, Release 6.7 DRAFT __ | RotateProperties window: WINDOW delta: INT16 properties: LISTofATOM |__ Errors: Atom, Match, Window If the property names in the list are viewed as being num- bered starting from zero, and there are N property names in the list, then the value associated with property name I becomes the value associated with property name (I + delta) mod N, for all I from zero to N - 1. The effect is to rotate the states by delta places around the virtual ring of property names (right for positive delta, left for negative delta). If delta mod N is nonzero, a PropertyNotify event is gener- ated for each property in the order listed. If an atom occurs more than once in the list or no property with that name is defined for the window, a Match error is generated. If an Atom or Match error is generated, no prop- erties are changed. __ | ListProperties window: WINDOW -> atoms: LISTofATOM |__ Errors: Window This request returns the atoms of properties currently defined on the window. __ | SetSelectionOwner selection: ATOM owner: WINDOW or None time: TIMESTAMP or CurrentTime |__ Errors: Atom, Window 35 X Protocol X11, Release 6.7 DRAFT This request changes the owner, owner window, and last- change time of the specified selection. This request has no effect if the specified time is earlier than the current last-change time of the specified selection or is later than the current server time. Otherwise, the last-change time is set to the specified time with CurrentTime replaced by the current server time. If the owner window is specified as None, then the owner of the selection becomes None (that is, no owner). Otherwise, the owner of the selection becomes the client executing the request. If the new owner (whether a client or None) is not the same as the current owner and the current owner is not None, then the current owner is sent a SelectionClear event. If the client that is the owner of a selection is later ter- minated (that is, its connection is closed) or if the owner window it has specified in the request is later destroyed, then the owner of the selection automatically reverts to None, but the last-change time is not affected. The selection atom is uninterpreted by the server. The owner window is returned by the GetSelectionOwner request and is reported in SelectionRequest and SelectionClear events. Selections are global to the server. __ | GetSelectionOwner selection: ATOM -> owner: WINDOW or None |__ Errors: Atom This request returns the current owner window of the speci- fied selection, if any. If None is returned, then there is no owner for the selection. 36 X Protocol X11, Release 6.7 DRAFT __ | ConvertSelection selection, target: ATOM property: ATOM or None requestor: WINDOW time: TIMESTAMP or CurrentTime |__ Errors: Atom, Window If the specified selection has an owner, the server sends a SelectionRequest event to that owner. If no owner for the specified selection exists, the server generates a Selec- tionNotify event to the requestor with property None. The arguments are passed on unchanged in either of the events. __ | SendEvent destination: WINDOW or PointerWindow or InputFocus propagate: BOOL event-mask: SETofEVENT event: |__ Errors: Value, Window If PointerWindow is specified, destination is replaced with the window that the pointer is in. If InputFocus is speci- fied and the focus window contains the pointer, destination is replaced with the window that the pointer is in. Other- wise, destination is replaced with the focus window. If the event-mask is the empty set, then the event is sent to the client that created the destination window. If that client no longer exists, no event is sent. If propagate is False, then the event is sent to every client selecting on destination any of the event types in event-mask. If propagate is True and no clients have selected on desti- nation any of the event types in event-mask, then destina- tion is replaced with the closest ancestor of destination for which some client has selected a type in event-mask and no intervening window has that type in its do-not-propagate- mask. If no such window exists or if the window is an ancestor of the focus window and InputFocus was originally specified as the destination, then the event is not sent to any clients. Otherwise, the event is reported to every client selecting on the final destination any of the types specified in event-mask. 37 X Protocol X11, Release 6.7 DRAFT The event code must be one of the core events or one of the events defined by an extension (or a Value error results) so that the server can correctly byte-swap the contents as nec- essary. The contents of the event are otherwise unaltered and unchecked by the server except to force on the most sig- nificant bit of the event code and to set the sequence num- ber in the event correctly. Active grabs are ignored for this request. __ | GrabPointer grab-window: WINDOW owner-events: BOOL event-mask: SETofPOINTEREVENT pointer-mode, keyboard-mode: {Synchronous, Asynchronous} confine-to: WINDOW or None cursor: CURSOR or None time: TIMESTAMP or CurrentTime -> status: {Success, AlreadyGrabbed, Frozen, InvalidTime, NotViewable} |__ Errors: Cursor, Value, Window This request actively grabs control of the pointer. Further pointer events are only reported to the grabbing client. The request overrides any active pointer grab by this client. If owner-events is False, all generated pointer events are reported with respect to grab-window and are only reported if selected by event-mask. If owner-events is True and a generated pointer event would normally be reported to this client, it is reported normally. Otherwise, the event is reported with respect to the grab-window and is only reported if selected by event-mask. For either value of owner-events, unreported events are simply discarded. If pointer-mode is Asynchronous, pointer event processing continues normally. If the pointer is currently frozen by this client, then processing of pointer events is resumed. If pointer-mode is Synchronous, the state of the pointer (as seen by means of the protocol) appears to freeze, and no further pointer events are generated by the server until the grabbing client issues a releasing AllowEvents request or until the pointer grab is released. Actual pointer changes are not lost while the pointer is frozen. They are simply queued for later processing. 38 X Protocol X11, Release 6.7 DRAFT If keyboard-mode is Asynchronous, keyboard event processing is unaffected by activation of the grab. If keyboard-mode is Synchronous, the state of the keyboard (as seen by means of the protocol) appears to freeze, and no further keyboard events are generated by the server until the grabbing client issues a releasing AllowEvents request or until the pointer grab is released. Actual keyboard changes are not lost while the keyboard is frozen. They are simply queued for later processing. If a cursor is specified, then it is displayed regardless of what window the pointer is in. If no cursor is specified, then when the pointer is in grab-window or one of its sub- windows, the normal cursor for that window is displayed. Otherwise, the cursor for grab-window is displayed. If a confine-to window is specified, then the pointer will be restricted to stay contained in that window. The con- fine-to window need have no relationship to the grab-window. If the pointer is not initially in the confine-to window, then it is warped automatically to the closest edge (and enter/leave events are generated normally) just before the grab activates. If the confine-to window is subsequently reconfigured, the pointer will be warped automatically as necessary to keep it contained in the window. This request generates EnterNotify and LeaveNotify events. The request fails with status AlreadyGrabbed if the pointer is actively grabbed by some other client. The request fails with status Frozen if the pointer is frozen by an active grab of another client. The request fails with status NotViewable if grab-window or confine-to window is not view- able or if the confine-to window lies completely outside the boundaries of the root window. The request fails with sta- tus InvalidTime if the specified time is earlier than the last-pointer-grab time or later than the current server time. Otherwise, the last-pointer-grab time is set to the specified time, with CurrentTime replaced by the current server time. __ | UngrabPointer |__ time: TIMESTAMP or CurrentTime This request releases the pointer if this client has it actively grabbed (from either GrabPointer or GrabButton or from a normal button press) and releases any queued events. The request has no effect if the specified time is earlier than the last-pointer-grab time or is later than the current server time. 39 X Protocol X11, Release 6.7 DRAFT This request generates EnterNotify and LeaveNotify events. An UngrabPointer request is performed automatically if the event window or confine-to window for an active pointer grab becomes not viewable or if window reconfiguration causes the confine-to window to lie completely outside the boundaries of the root window. __ | GrabButton modifiers: SETofKEYMASK or AnyModifier button: BUTTON or AnyButton grab-window: WINDOW owner-events: BOOL event-mask: SETofPOINTEREVENT pointer-mode, keyboard-mode: {Synchronous, Asynchronous} confine-to: WINDOW or None cursor: CURSOR or None |__ Errors: Access, Cursor, Value, Window This request establishes a passive grab. In the future, the pointer is actively grabbed as described in GrabPointer, the last-pointer-grab time is set to the time at which the but- ton was pressed (as transmitted in the ButtonPress event), and the ButtonPress event is reported if all of the follow- ing conditions are true: o The pointer is not grabbed and the specified button is logically pressed when the specified modifier keys are logically down, and no other buttons or modifier keys are logically down. o The grab-window contains the pointer. o The confine-to window (if any) is viewable. o A passive grab on the same button/key combination does not exist on any ancestor of grab-window. The interpretation of the remaining arguments is the same as for GrabPointer. The active grab is terminated automati- cally when the logical state of the pointer has all buttons released, independent of the logical state of modifier keys. Note that the logical state of a device (as seen by means of the protocol) may lag the physical state if device event processing is frozen. This request overrides all previous passive grabs by the same client on the same button/key combinations on the same window. A modifier of AnyModifier is equivalent to issuing 40 X Protocol X11, Release 6.7 DRAFT the request for all possible modifier combinations (includ- ing the combination of no modifiers). It is not required that all specified modifiers have currently assigned key- codes. A button of AnyButton is equivalent to issuing the request for all possible buttons. Otherwise, it is not required that the button specified currently be assigned to a physical button. An Access error is generated if some other client has already issued a GrabButton request with the same button/key combination on the same window. When using AnyModifier or AnyButton, the request fails completely (no grabs are estab- lished), and an Access error is generated if there is a con- flicting grab for any combination. The request has no effect on an active grab. __ | UngrabButton modifiers: SETofKEYMASK or AnyModifier button: BUTTON or AnyButton grab-window: WINDOW |__ Errors: Value, Window This request releases the passive button/key combination on the specified window if it was grabbed by this client. A modifiers argument of AnyModifier is equivalent to issuing the request for all possible modifier combinations (includ- ing the combination of no modifiers). A button of AnyButton is equivalent to issuing the request for all possible but- tons. The request has no effect on an active grab. __ | ChangeActivePointerGrab event-mask: SETofPOINTEREVENT cursor: CURSOR or None time: TIMESTAMP or CurrentTime |__ Errors: Cursor, Value This request changes the specified dynamic parameters if the pointer is actively grabbed by the client and the specified time is no earlier than the last-pointer-grab time and no later than the current server time. The interpretation of event-mask and cursor are the same as in GrabPointer. This request has no effect on the parameters of any passive grabs established with GrabButton. 41 X Protocol X11, Release 6.7 DRAFT __ | GrabKeyboard grab-window: WINDOW owner-events: BOOL pointer-mode, keyboard-mode: {Synchronous, Asynchronous} time: TIMESTAMP or CurrentTime -> status: {Success, AlreadyGrabbed, Frozen, InvalidTime, NotViewable} |__ Errors: Value, Window This request actively grabs control of the keyboard. Fur- ther key events are reported only to the grabbing client. This request overrides any active keyboard grab by this client. If owner-events is False, all generated key events are reported with respect to grab-window. If owner-events is True and if a generated key event would normally be reported to this client, it is reported normally. Otherwise, the event is reported with respect to the grab-window. Both KeyPress and KeyRelease events are always reported, indepen- dent of any event selection made by the client. If keyboard-mode is Asynchronous, keyboard event processing continues normally. If the keyboard is currently frozen by this client, then processing of keyboard events is resumed. If keyboard-mode is Synchronous, the state of the keyboard (as seen by means of the protocol) appears to freeze. No further keyboard events are generated by the server until the grabbing client issues a releasing AllowEvents request or until the keyboard grab is released. Actual keyboard changes are not lost while the keyboard is frozen. They are simply queued for later processing. If pointer-mode is Asynchronous, pointer event processing is unaffected by activation of the grab. If pointer-mode is Synchronous, the state of the pointer (as seen by means of the protocol) appears to freeze. No further pointer events are generated by the server until the grabbing client issues a releasing AllowEvents request or until the keyboard grab is released. Actual pointer changes are not lost while the pointer is frozen. They are simply queued for later pro- cessing. This request generates FocusIn and FocusOut events. The request fails with status AlreadyGrabbed if the keyboard is actively grabbed by some other client. The request fails with status Frozen if the keyboard is frozen by an active 42 X Protocol X11, Release 6.7 DRAFT grab of another client. The request fails with status NotViewable if grab-window is not viewable. The request fails with status InvalidTime if the specified time is ear- lier than the last-keyboard-grab time or later than the cur- rent server time. Otherwise, the last-keyboard-grab time is set to the specified time with CurrentTime replaced by the current server time. __ | UngrabKeyboard |__ time: TIMESTAMP or CurrentTime This request releases the keyboard if this client has it actively grabbed (as a result of either GrabKeyboard or GrabKey) and releases any queued events. The request has no effect if the specified time is earlier than the last-key- board-grab time or is later than the current server time. This request generates FocusIn and FocusOut events. An UngrabKeyboard is performed automatically if the event window for an active keyboard grab becomes not viewable. __ | GrabKey key: KEYCODE or AnyKey modifiers: SETofKEYMASK or AnyModifier grab-window: WINDOW owner-events: BOOL pointer-mode, keyboard-mode: {Synchronous, Asynchronous} |__ Errors: Access, Value, Window This request establishes a passive grab on the keyboard. In the future, the keyboard is actively grabbed as described in GrabKeyboard, the last-keyboard-grab time is set to the time at which the key was pressed (as transmitted in the KeyPress event), and the KeyPress event is reported if all of the following conditions are true: o The keyboard is not grabbed and the specified key (which can itself be a modifier key) is logically pressed when the specified modifier keys are logically down, and no other modifier keys are logically down. o Either the grab-window is an ancestor of (or is) the focus window, or the grab-window is a descendent of the focus window and contains the pointer. 43 X Protocol X11, Release 6.7 DRAFT o A passive grab on the same key combination does not exist on any ancestor of grab-window. The interpretation of the remaining arguments is the same as for GrabKeyboard. The active grab is terminated automati- cally when the logical state of the keyboard has the speci- fied key released, independent of the logical state of modi- fier keys. Note that the logical state of a device (as seen by means of the protocol) may lag the physical state if device event processing is frozen. This request overrides all previous passive grabs by the same client on the same key combinations on the same window. A modifier of AnyModifier is equivalent to issuing the request for all possible modifier combinations (including the combination of no modifiers). It is not required that all modifiers specified have currently assigned keycodes. A key of AnyKey is equivalent to issuing the request for all possible keycodes. Otherwise, the key must be in the range specified by min-keycode and max-keycode in the connection setup (or a Value error results). An Access error is generated if some other client has issued a GrabKey with the same key combination on the same window. When using AnyModifier or AnyKey, the request fails com- pletely (no grabs are established), and an Access error is generated if there is a conflicting grab for any combina- tion. __ | UngrabKey key: KEYCODE or AnyKey modifiers: SETofKEYMASK or AnyModifier grab-window: WINDOW |__ Errors: Value, Window This request releases the key combination on the specified window if it was grabbed by this client. A modifiers argu- ment of AnyModifier is equivalent to issuing the request for all possible modifier combinations (including the combina- tion of no modifiers). A key of AnyKey is equivalent to issuing the request for all possible keycodes. This request has no effect on an active grab. 44 X Protocol X11, Release 6.7 DRAFT __ | AllowEvents mode: {AsyncPointer, SyncPointer, ReplayPointer, AsyncKey- board, SyncKeyboard, ReplayKeyboard, AsyncBoth, SyncBoth} time: TIMESTAMP or CurrentTime |__ Errors: Value This request releases some queued events if the client has caused a device to freeze. The request has no effect if the specified time is earlier than the last-grab time of the most recent active grab for the client or if the specified time is later than the current server time. For AsyncPointer, if the pointer is frozen by the client, pointer event processing continues normally. If the pointer is frozen twice by the client on behalf of two separate grabs, AsyncPointer thaws for both. AsyncPointer has no effect if the pointer is not frozen by the client, but the pointer need not be grabbed by the client. For SyncPointer, if the pointer is frozen and actively grabbed by the client, pointer event processing continues normally until the next ButtonPress or ButtonRelease event is reported to the client, at which time the pointer again appears to freeze. However, if the reported event causes the pointer grab to be released, then the pointer does not freeze. SyncPointer has no effect if the pointer is not frozen by the client or if the pointer is not grabbed by the client. For ReplayPointer, if the pointer is actively grabbed by the client and is frozen as the result of an event having been sent to the client (either from the activation of a GrabBut- ton or from a previous AllowEvents with mode SyncPointer but not from a GrabPointer), then the pointer grab is released and that event is completely reprocessed, this time ignoring any passive grabs at or above (towards the root) the grab- window of the grab just released. The request has no effect if the pointer is not grabbed by the client or if the pointer is not frozen as the result of an event. For AsyncKeyboard, if the keyboard is frozen by the client, keyboard event processing continues normally. If the key- board is frozen twice by the client on behalf of two sepa- rate grabs, AsyncKeyboard thaws for both. AsyncKeyboard has no effect if the keyboard is not frozen by the client, but the keyboard need not be grabbed by the client. For SyncKeyboard, if the keyboard is frozen and actively grabbed by the client, keyboard event processing continues 45 X Protocol X11, Release 6.7 DRAFT normally until the next KeyPress or KeyRelease event is reported to the client, at which time the keyboard again appears to freeze. However, if the reported event causes the keyboard grab to be released, then the keyboard does not freeze. SyncKeyboard has no effect if the keyboard is not frozen by the client or if the keyboard is not grabbed by the client. For ReplayKeyboard, if the keyboard is actively grabbed by the client and is frozen as the result of an event having been sent to the client (either from the activation of a GrabKey or from a previous AllowEvents with mode SyncKey- board but not from a GrabKeyboard), then the keyboard grab is released and that event is completely reprocessed, this time ignoring any passive grabs at or above (towards the root) the grab-window of the grab just released. The request has no effect if the keyboard is not grabbed by the client or if the keyboard is not frozen as the result of an event. For SyncBoth, if both pointer and keyboard are frozen by the client, event processing (for both devices) continues nor- mally until the next ButtonPress, ButtonRelease, KeyPress, or KeyRelease event is reported to the client for a grabbed device (button event for the pointer, key event for the key- board), at which time the devices again appear to freeze. However, if the reported event causes the grab to be released, then the devices do not freeze (but if the other device is still grabbed, then a subsequent event for it will still cause both devices to freeze). SyncBoth has no effect unless both pointer and keyboard are frozen by the client. If the pointer or keyboard is frozen twice by the client on behalf of two separate grabs, SyncBoth thaws for both (but a subsequent freeze for SyncBoth will only freeze each device once). For AsyncBoth, if the pointer and the keyboard are frozen by the client, event processing for both devices continues nor- mally. If a device is frozen twice by the client on behalf of two separate grabs, AsyncBoth thaws for both. AsyncBoth has no effect unless both pointer and keyboard are frozen by the client. AsyncPointer, SyncPointer, and ReplayPointer have no effect on processing of keyboard events. AsyncKeyboard, SyncKey- board, and ReplayKeyboard have no effect on processing of pointer events. It is possible for both a pointer grab and a keyboard grab to be active simultaneously (by the same or different clients). When a device is frozen on behalf of either grab, no event processing is performed for the device. It is pos- sible for a single device to be frozen because of both grabs. In this case, the freeze must be released on behalf 46 X Protocol X11, Release 6.7 DRAFT of both grabs before events can again be processed. If a device is frozen twice by a single client, then a single AllowEvents releases both. __ |__ GrabServer This request disables processing of requests and close-downs on all connections other than the one this request arrived on. __ |__ UngrabServer This request restarts processing of requests and close-downs on other connections. __ | QueryPointer window: WINDOW -> root: WINDOW child: WINDOW or None same-screen: BOOL root-x, root-y, win-x, win-y: INT16 mask: SETofKEYBUTMASK |__ Errors: Window The root window the pointer is logically on and the pointer coordinates relative to the root's origin are returned. If same-screen is False, then the pointer is not on the same screen as the argument window, child is None, and win-x and win-y are zero. If same-screen is True, then win-x and win- y are the pointer coordinates relative to the argument win- dow's origin, and child is the child containing the pointer, if any. The current logical state of the modifier keys and the buttons are also returned. Note that the logical state of a device (as seen by means of the protocol) may lag the physical state if device event processing is frozen. 47 X Protocol X11, Release 6.7 DRAFT __ | GetMotionEvents start, stop: TIMESTAMP or CurrentTime window: WINDOW -> events: LISTofTIMECOORD where: TIMECOORD: [x, y: INT16 time: TIMESTAMP] |__ Errors: Window This request returns all events in the motion history buffer that fall between the specified start and stop times (inclu- sive) and that have coordinates that lie within (including borders) the specified window at its present placement. The x and y coordinates are reported relative to the origin of the window. If the start time is later than the stop time or if the start time is in the future, no events are returned. If the stop time is in the future, it is equivalent to specifying CurrentTime. __ | TranslateCoordinates src-window, dst-window: WINDOW src-x, src-y: INT16 -> same-screen: BOOL child: WINDOW or None dst-x, dst-y: INT16 |__ Errors: Window The src-x and src-y coordinates are taken relative to src- window's origin and are returned as dst-x and dst-y coordi- nates relative to dst-window's origin. If same-screen is False, then src-window and dst-window are on different screens, and dst-x and dst-y are zero. If the coordinates are contained in a mapped child of dst-window, then that child is returned. 48 X Protocol X11, Release 6.7 DRAFT __ | WarpPointer src-window: WINDOW or None dst-window: WINDOW or None src-x, src-y: INT16 src-width, src-height: CARD16 dst-x, dst-y: INT16 |__ Errors: Window If dst-window is None, this request moves the pointer by offsets [dst-x, dst-y] relative to the current position of the pointer. If dst-window is a window, this request moves the pointer to [dst-x, dst-y] relative to dst-window's ori- gin. However, if src-window is not None, the move only takes place if src-window contains the pointer and the pointer is contained in the specified rectangle of src-win- dow. The src-x and src-y coordinates are relative to src-window's origin. If src-height is zero, it is replaced with the cur- rent height of src-window minus src-y. If src-width is zero, it is replaced with the current width of src-window minus src-x. This request cannot be used to move the pointer outside the confine-to window of an active pointer grab. An attempt will only move the pointer as far as the closest edge of the confine-to window. This request will generate events just as if the user had instantaneously moved the pointer. __ | SetInputFocus focus: WINDOW or PointerRoot or None revert-to: {Parent, PointerRoot, None} time: TIMESTAMP or CurrentTime |__ Errors: Match, Value, Window This request changes the input focus and the last-focus- change time. The request has no effect if the specified time is earlier than the current last-focus-change time or is later than the current server time. Otherwise, the last- focus-change time is set to the specified time with Current- Time replaced by the current server time. If None is specified as the focus, all keyboard events are discarded until a new focus window is set. In this case, 49 X Protocol X11, Release 6.7 DRAFT the revert-to argument is ignored. If a window is specified as the focus, it becomes the key- board's focus window. If a generated keyboard event would normally be reported to this window or one of its inferiors, the event is reported normally. Otherwise, the event is reported with respect to the focus window. If PointerRoot is specified as the focus, the focus window is dynamically taken to be the root window of whatever screen the pointer is on at each keyboard event. In this case, the revert-to argument is ignored. This request generates FocusIn and FocusOut events. The specified focus window must be viewable at the time of the request (or a Match error results). If the focus window later becomes not viewable, the new focus window depends on the revert-to argument. If revert-to is Parent, the focus reverts to the parent (or the closest viewable ancestor) and the new revert-to value is taken to be None. If revert-to is PointerRoot or None, the focus reverts to that value. When the focus reverts, FocusIn and FocusOut events are gen- erated, but the last-focus-change time is not affected. __ | GetInputFocus -> focus: WINDOW or PointerRoot or None |__ revert-to: {Parent, PointerRoot, None} This request returns the current focus state. __ | QueryKeymap -> |__ keys: LISTofCARD8 This request returns a bit vector for the logical state of the keyboard. Each bit set to 1 indicates that the corre- sponding key is currently pressed. The vector is repre- sented as 32 bytes. Byte N (from 0) contains the bits for keys 8N to 8N + 7 with the least significant bit in the byte representing key 8N. Note that the logical state of a device (as seen by means of the protocol) may lag the physi- cal state if device event processing is frozen. 50 X Protocol X11, Release 6.7 DRAFT __ | OpenFont fid: FONT name: STRING8 |__ Errors: Alloc, IDChoice, Name This request loads the specified font, if necessary, and as- sociates identifier fid with it. The font name should use the ISO Latin-1 encoding, and uppercase and lowercase do not matter. When the characters ``?'' and ``*'' are used in a font name, a pattern match is performed and any matching font is used. In the pattern, the ``?'' character (octal value 77) will match any single character, and the ``*'' character (octal value 52) will match any number of charac- ters. A structured format for font names is specified in the X.Org standard X Logical Font Description Conventions. Fonts are not associated with a particular screen and can be stored as a component of any graphics context. __ | CloseFont font: FONT |__ Errors: Font This request deletes the association between the resource ID and the font. The font itself will be freed when no other resource references it. 51 X Protocol X11, Release 6.7 DRAFT __ | QueryFont font: FONTABLE -> font-info: FONTINFO char-infos: LISTofCHARINFO where: FONTINFO: [draw-direction: {LeftToRight, RightToLeft} min-char-or-byte2, max-char-or-byte2: CARD16 min-byte1, max-byte1: CARD8 all-chars-exist: BOOL default-char: CARD16 min-bounds: CHARINFO max-bounds: CHARINFO font-ascent: INT16 font-descent: INT16 properties: LISTofFONTPROP] FONTPROP: [name: ATOM value: <32-bit-value>] CHARINFO: [left-side-bearing: INT16 right-side-bearing: INT16 character-width: INT16 ascent: INT16 descent: INT16 attributes: CARD16] |__ Errors: Font This request returns logical information about a font. If a gcontext is given for font, the currently contained font is used. The draw-direction is just a hint and indicates whether most char-infos have a positive, LeftToRight, or a negative, RightToLeft, character-width metric. The core protocol defines no support for vertical text. If min-byte1 and max-byte1 are both zero, then min-char-or- byte2 specifies the linear character index corresponding to the first element of char-infos, and max-char-or-byte2 spec- ifies the linear character index of the last element. If either min-byte1 or max-byte1 are nonzero, then both min- char-or-byte2 and max-char-or-byte2 will be less than 256, and the 2-byte character index values corresponding to char- infos element N (counting from 0) are: 52 X Protocol X11, Release 6.7 DRAFT byte1 = N/D + min-byte1 byte2 = N\\D + min-char-or-byte2 where: D = max-char-or-byte2 - min-char-or-byte2 + 1 / = integer division \\ = integer modulus If char-infos has length zero, then min-bounds and max- bounds will be identical, and the effective char-infos is one filled with this char-info, of length: L = D * (max-byte1 - min-byte1 + 1) That is, all glyphs in the specified linear or matrix range have the same information, as given by min-bounds (and max- bounds). If all-chars-exist is True, then all characters in char-infos have nonzero bounding boxes. The default-char specifies the character that will be used when an undefined or nonexistent character is used. Note that default-char is a CARD16, not CHAR2B. For a font using 2-byte matrix format, the default-char has byte1 in the most significant byte and byte2 in the least significant byte. If the default-char itself specifies an undefined or nonex- istent character, then no printing is performed for an unde- fined or nonexistent character. The min-bounds and max-bounds contain the minimum and maxi- mum values of each individual CHARINFO component over all char-infos (ignoring nonexistent characters). The bounding box of the font (that is, the smallest rectangle enclosing the shape obtained by superimposing all characters at the same origin [x,y]) has its upper-left coordinate at: [x + min-bounds.left-side-bearing, y - max-bounds.ascent] with a width of: max-bounds.right-side-bearing - min-bounds.left-side-bearing and a height of: max-bounds.ascent + max-bounds.descent The font-ascent is the logical extent of the font above the baseline and is used for determining line spacing. Specific characters may extend beyond this. The font-descent is the 53 X Protocol X11, Release 6.7 DRAFT logical extent of the font at or below the baseline and is used for determining line spacing. Specific characters may extend beyond this. If the baseline is at Y-coordinate y, then the logical extent of the font is inclusive between the Y-coordinate values (y - font-ascent) and (y + font-descent - 1). A font is not guaranteed to have any properties. The inter- pretation of the property value (for example, INT32, CARD32) must be derived from a priori knowledge of the property. A basic set of font properties is specified in the X.Org stan- dard X Logical Font Description Conventions. For a character origin at [x,y], the bounding box of a char- acter (that is, the smallest rectangle enclosing the charac- ter's shape), described in terms of CHARINFO components, is a rectangle with its upper-left corner at: [x + left-side-bearing, y - ascent] with a width of: right-side-bearing - left-side-bearing and a height of: ascent + descent and the origin for the next character is defined to be: [x + character-width, y] Note that the baseline is logically viewed as being just below nondescending characters (when descent is zero, only pixels with Y-coordinates less than y are drawn) and that the origin is logically viewed as being coincident with the left edge of a nonkerned character (when left-side-bearing is zero, no pixels with X-coordinate less than x are drawn). Note that CHARINFO metric values can be negative. A nonexistent character is represented with all CHARINFO components zero. The interpretation of the per-character attributes field is server-dependent. 54 X Protocol X11, Release 6.7 DRAFT __ | QueryTextExtents font: FONTABLE string: STRING16 -> draw-direction: {LeftToRight, RightToLeft} font-ascent: INT16 font-descent: INT16 overall-ascent: INT16 overall-descent: INT16 overall-width: INT32 overall-left: INT32 overall-right: INT32 |__ Errors: Font This request returns the logical extents of the specified string of characters in the specified font. If a gcontext is given for font, the currently contained font is used. The draw-direction, font-ascent, and font-descent are the same as described in QueryFont. The overall-ascent is the maximum of the ascent metrics of all characters in the string, and the overall-descent is the maximum of the descent metrics. The overall-width is the sum of the char- acter-width metrics of all characters in the string. For each character in the string, let W be the sum of the char- acter-width metrics of all characters preceding it in the string, let L be the left-side-bearing metric of the charac- ter plus W, and let R be the right-side-bearing metric of the character plus W. The overall-left is the minimum L of all characters in the string, and the overall-right is the maximum R. For fonts defined with linear indexing rather than 2-byte matrix indexing, the server will interpret each CHAR2B as a 16-bit number that has been transmitted most significant byte first (that is, byte1 of the CHAR2B is taken as the most significant byte). Characters with all zero metrics are ignored. If the font has no defined default-char, then undefined characters in the string are also ignored. 55 X Protocol X11, Release 6.7 DRAFT __ | ListFonts pattern: STRING8 max-names: CARD16 -> |__ names: LISTofSTRING8 This request returns a list of available font names (as con- trolled by the font search path; see SetFontPath request) that match the pattern. At most, max-names names will be returned. The pattern should use the ISO Latin-1 encoding, and uppercase and lowercase do not matter. In the pattern, the ``?'' character (octal value 77) will match any single character, and the ``*'' character (octal value 52) will match any number of characters. The returned names are in lowercase. __ | ListFontsWithInfo pattern: STRING8 max-names: CARD16 -> name: STRING8 info FONTINFO replies-hint: CARD32 where: |__ FONTINFO: This request is similar to ListFonts, but it also returns information about each font. The information returned for each font is identical to what QueryFont would return except that the per-character metrics are not returned. Note that this request can generate multiple replies. With each reply, replies-hint may provide an indication of how many more fonts will be returned. This number is a hint only and may be larger or smaller than the number of fonts actually returned. A zero value does not guarantee that no more fonts will be returned. After the font replies, a reply with a zero-length name is sent to indicate the end of the reply sequence. 56 X Protocol X11, Release 6.7 DRAFT __ | SetFontPath path: LISTofSTRING8 |__ Errors: Value This request defines the search path for font lookup. There is only one search path per server, not one per client. The interpretation of the strings is operating-system-dependent, but the strings are intended to specify directories to be searched in the order listed. Setting the path to the empty list restores the default path defined for the server. As a side effect of executing this request, the server is guaranteed to flush all cached information about fonts for which there currently are no explicit resource IDs allo- cated. The meaning of an error from this request is system spe- cific. __ | GetFontPath -> |__ path: LISTofSTRING8 This request returns the current search path for fonts. __ | CreatePixmap pid: PIXMAP drawable: DRAWABLE depth: CARD8 width, height: CARD16 |__ Errors: Alloc, Drawable, IDChoice, Value This request creates a pixmap and assigns the identifier pid to it. The width and height must be nonzero (or a Value error results). The depth must be one of the depths sup- ported by the root of the specified drawable (or a Value error results). The initial contents of the pixmap are undefined. 57 X Protocol X11, Release 6.7 DRAFT It is legal to pass an InputOnly window as a drawable to this request. __ | FreePixmap pixmap: PIXMAP |__ Errors: Pixmap This request deletes the association between the resource ID and the pixmap. The pixmap storage will be freed when no other resource references it. __ | CreateGC cid: GCONTEXT drawable: DRAWABLE value-mask: BITMASK value-list: LISTofVALUE Errors: Alloc, Drawable, Font, IDChoice, Match, Pixmap, |__ Value This request creates a graphics context and assigns the identifier cid to it. The gcontext can be used with any destination drawable having the same root and depth as the specified drawable; use with other drawables results in a Match error. The value-mask and value-list specify which components are to be explicitly initialized. The context components are: ------------------------------------------------------------- Component Type ------------------------------------------------------------- function {Clear, And, AndReverse, Copy, AndIn- verted, NoOp, Xor, Or, Nor, Equiv, Invert, OrReverse, Copy- Inverted, OrInverted, Nand, Set} plane-mask CARD32 foreground CARD32 background CARD32 line-width CARD16 line-style {Solid, OnOffDash, DoubleDash} cap-style {NotLast, Butt, Round, Projecting} join-style {Miter, Round, Bevel} 58 X Protocol X11, Release 6.7 DRAFT ------------------------------------------------------------- Component Type ------------------------------------------------------------- fill-style {Solid, Tiled, OpaqueStippled, Stippled} fill-rule {EvenOdd, Winding} arc-mode {Chord, PieSlice} tile PIXMAP stipple PIXMAP tile-stipple-x- INT16 origin tile-stipple-y- INT16 origin font FONT subwindow-mode {ClipByChildren, IncludeInferiors} graphics-expo- BOOL sures clip-x-origin INT16 clip-y-origin INT16 clip-mask PIXMAP or None dash-offset CARD16 dashes CARD8 ------------------------------------------------------------- In graphics operations, given a source and destination pixel, the result is computed bitwise on corresponding bits of the pixels; that is, a Boolean operation is performed in each bit plane. The plane-mask restricts the operation to a subset of planes, so the result is: ((src FUNC dst) AND plane-mask) OR (dst AND (NOT plane-mask)) Range checking is not performed on the values for fore- ground, background, or plane-mask. They are simply trun- cated to the appropriate number of bits. The meanings of the functions are: --------------------------------------- Function Operation --------------------------------------- Clear 0 And src AND dst AndReverse src AND (NOT dst) Copy src AndInverted (NOT src) AND dst NoOp dst Xor src XOR dst Or src OR dst Nor (NOT src) AND (NOT dst) 59 X Protocol X11, Release 6.7 DRAFT Equiv (NOT src) XOR dst Invert NOT dst OrReverse src OR (NOT dst) CopyInverted NOT src OrInverted (NOT src) OR dst Nand (NOT src) OR (NOT dst) Set 1 --------------------------------------- The line-width is measured in pixels and can be greater than or equal to one, a wide line, or the special value zero, a thin line. Wide lines are drawn centered on the path described by the graphics request. Unless otherwise specified by the join or cap style, the bounding box of a wide line with endpoints [x1, y1], [x2, y2] and width w is a rectangle with vertices at the following real coordinates: [x1-(w*sn/2), y1+(w*cs/2)], [x1+(w*sn/2), y1-(w*cs/2)], [x2-(w*sn/2), y2+(w*cs/2)], [x2+(w*sn/2), y2-(w*cs/2)] The sn is the sine of the angle of the line and cs is the cosine of the angle of the line. A pixel is part of the line (and hence drawn) if the center of the pixel is fully inside the bounding box, which is viewed as having infinite- ly thin edges. If the center of the pixel is exactly on the bounding box, it is part of the line if and only if the interior is immediately to its right (x increasing direc- tion). Pixels with centers on a horizontal edge are a spe- cial case and are part of the line if and only if the inte- rior or the boundary is immediately below (y increasing direction) and if the interior or the boundary is immedi- ately to the right (x increasing direction). Note that this description is a mathematical model describing the pixels that are drawn for a wide line and does not imply that trigonometry is required to implement such a model. Real or fixed point arithmetic is recommended for computing the cor- ners of the line endpoints for lines greater than one pixel in width. Thin lines (zero line-width) are nominally one pixel wide lines drawn using an unspecified, device-dependent algo- rithm. There are only two constraints on this algorithm. First, if a line is drawn unclipped from [x1,y1] to [x2,y2] and another line is drawn unclipped from [x1+dx,y1+dy] to [x2+dx,y2+dy], then a point [x,y] is touched by drawing the first line if and only if the point [x+dx,y+dy] is touched by drawing the second line. Second, the effective set of points comprising a line cannot be affected by clipping. Thus, a point is touched in a clipped line if and only if 60 X Protocol X11, Release 6.7 DRAFT the point lies inside the clipping region and the point would be touched by the line when drawn unclipped. Note that a wide line drawn from [x1,y1] to [x2,y2] always draws the same pixels as a wide line drawn from [x2,y2] to [x1,y1], not counting cap-style and join-style. Implemen- tors are encouraged to make this property true for thin lines, but it is not required. A line-width of zero may differ from a line-width of one in which pixels are drawn. In general, drawing a thin line will be faster than drawing a wide line of width one, but thin lines may not mix well aesthetically with wide lines because of the different draw- ing algorithms. If it is desirable to obtain precise and uniform results across all displays, a client should always use a line-width of one, rather than a line-width of zero. The line-style defines which sections of a line are drawn: Solid The full path of the line is drawn. DoubleDash The full path of the line is drawn, but the even dashes are filled differently than the odd dashes (see fill-style), with Butt cap-style used where even and odd dashes meet. OnOffDash Only the even dashes are drawn, and cap-style applies to all internal ends of the individual dashes (except NotLast is treated as Butt). The cap-style defines how the endpoints of a path are drawn: NotLast The result is equivalent to Butt, except that for a line-width of zero the final endpoint is not drawn. Butt The result is square at the endpoint (perpen- dicular to the slope of the line) with no pro- jection beyond. Round The result is a circular arc with its diameter equal to the line-width, centered on the end- point; it is equivalent to Butt for line-width zero. Projecting The result is square at the end, but the path continues beyond the endpoint for a distance equal to half the line-width; it is equivalent to Butt for line-width zero. The join-style defines how corners are drawn for wide lines: Miter The outer edges of the two lines extend to meet at an angle. However, if the angle is less than 11 degrees, a Bevel join-style is used instead. 61 X Protocol X11, Release 6.7 DRAFT Round The result is a circular arc with a diameter equal to the line-width, centered on the join- point. Bevel The result is Butt endpoint styles, and then the triangular notch is filled. For a line with coincident endpoints (x1=x2, y1=y2), when the cap-style is applied to both endpoints, the semantics depends on the line-width and the cap-style: NotLast thin This is device-dependent, but the desired effect is that nothing is drawn. Butt thin This is device-dependent, but the desired effect is that a single pixel is drawn. Round thin This is the same as Butt/thin. Projecting thin This is the same as Butt/thin. Butt wide Nothing is drawn. Round wide The closed path is a circle, centered at the endpoint and with a diameter equal to the line-width. Projecting wide The closed path is a square, aligned with the coordinate axes, centered at the end- point and with sides equal to the line- width. For a line with coincident endpoints (x1=x2, y1=y2), when the join-style is applied at one or both endpoints, the effect is as if the line was removed from the overall path. However, if the total path consists of (or is reduced to) a single point joined with itself, the effect is the same as when the cap-style is applied at both endpoints. The tile/stipple represents an infinite two-dimensional plane with the tile/stipple replicated in all dimensions. When that plane is superimposed on the drawable for use in a graphics operation, the upper-left corner of some instance of the tile/stipple is at the coordinates within the draw- able specified by the tile/stipple origin. The tile/stipple and clip origins are interpreted relative to the origin of whatever destination drawable is specified in a graphics request. The tile pixmap must have the same root and depth as the gcontext (or a Match error results). The stipple pixmap must have depth one and must have the same root as the gcon- text (or a Match error results). For fill-style Stippled (but not fill-style OpaqueStippled), the stipple pattern is tiled in a single plane and acts as an additional clip mask to be ANDed with the clip-mask. Any size pixmap can be used for tiling or stippling, although some sizes may be faster to use than others. 62 X Protocol X11, Release 6.7 DRAFT The fill-style defines the contents of the source for line, text, and fill requests. For all text and fill requests (for example, PolyText8, PolyText16, PolyFillRectangle, FillPoly, and PolyFillArc) as well as for line requests with line-style Solid, (for example, PolyLine, PolySegment, PolyRectangle, PolyArc) and for the even dashes for line requests with line-style OnOffDash or DoubleDash: Solid Foreground Tiled Tile OpaqueStip- A tile with the same width and height as pled stipple but with background everywhere stip- ple has a zero and with foreground everywhere stipple has a one Stippled Foreground masked by stipple For the odd dashes for line requests with line-style Dou- bleDash: Solid Background Tiled Same as for even dashes OpaqueStip- Same as for even dashes pled Stippled Background masked by stipple The dashes value allowed here is actually a simplified form of the more general patterns that can be set with SetDashes. Specifying a value of N here is equivalent to specifying the two element list [N, N] in SetDashes. The value must be nonzero (or a Value error results). The meaning of dash- offset and dashes are explained in the SetDashes request. The clip-mask restricts writes to the destination drawable. Only pixels where the clip-mask has bits set to 1 are drawn. Pixels are not drawn outside the area covered by the clip- mask or where the clip-mask has bits set to 0. The clip- mask affects all graphics requests, but it does not clip sources. The clip-mask origin is interpreted relative to the origin of whatever destination drawable is specified in a graphics request. If a pixmap is specified as the clip- mask, it must have depth 1 and have the same root as the gcontext (or a Match error results). If clip-mask is None, then pixels are always drawn, regardless of the clip origin. The clip-mask can also be set with the SetClipRectangles request. For ClipByChildren, both source and destination windows are additionally clipped by all viewable InputOutput children. For IncludeInferiors, neither source nor destination window is clipped by inferiors. This will result in including sub- window contents in the source and drawing through subwindow boundaries of the destination. The use of IncludeInferiors 63 X Protocol X11, Release 6.7 DRAFT with a source or destination window of one depth with mapped inferiors of differing depth is not illegal, but the seman- tics is undefined by the core protocol. The fill-rule defines what pixels are inside (that is, are drawn) for paths given in FillPoly requests. EvenOdd means a point is inside if an infinite ray with the point as ori- gin crosses the path an odd number of times. For Winding, a point is inside if an infinite ray with the point as origin crosses an unequal number of clockwise and counterclockwise directed path segments. A clockwise directed path segment is one that crosses the ray from left to right as observed from the point. A counter-clockwise segment is one that crosses the ray from right to left as observed from the point. The case where a directed line segment is coincident with the ray is uninteresting because one can simply choose a different ray that is not coincident with a segment. For both fill rules, a point is infinitely small and the path is an infinitely thin line. A pixel is inside if the center point of the pixel is inside and the center point is not on the boundary. If the center point is on the bound- ary, the pixel is inside if and only if the polygon interior is immediately to its right (x increasing direction). Pix- els with centers along a horizontal edge are a special case and are inside if and only if the polygon interior is imme- diately below (y increasing direction). The arc-mode controls filling in the PolyFillArc request. The graphics-exposures flag controls GraphicsExposure event generation for CopyArea and CopyPlane requests (and any sim- ilar requests defined by extensions). The default component values are: --------------------------------------------------------------- Component Default --------------------------------------------------------------- function Copy plane-mask all ones foreground 0 background 1 line-width 0 line-style Solid cap-style Butt join-style Miter fill-style Solid fill-rule EvenOdd arc-mode PieSlice 64 X Protocol X11, Release 6.7 DRAFT --------------------------------------------------------------- Component Default --------------------------------------------------------------- tile Pixmap of unspecified size filled with foreground pixel (that is, client specified pixel if any, else 0) (subsequent changes to foreground do not affect this pixmap) stipple Pixmap of unspecified size filled with ones tile-stipple-x-ori- 0 gin tile-stipple-y-ori- 0 gin font subwindow-mode ClipByChildren graphics-exposures True clip-x-origin 0 clip-y-origin 0 clip-mask None dash-offset 0 dashes 4 (that is, the list [4, 4]) --------------------------------------------------------------- Storing a pixmap in a gcontext might or might not result in a copy being made. If the pixmap is later used as the des- tination for a graphics request, the change might or might not be reflected in the gcontext. If the pixmap is used simultaneously in a graphics request as both a destination and as a tile or stipple, the results are not defined. It is quite likely that some amount of gcontext information will be cached in display hardware and that such hardware can only cache a small number of gcontexts. Given the num- ber and complexity of components, clients should view switching between gcontexts with nearly identical state as significantly more expensive than making minor changes to a single gcontext. __ | ChangeGC gc: GCONTEXT value-mask: BITMASK value-list: LISTofVALUE |__ Errors: Alloc, Font, GContext, Match, Pixmap, Value This request changes components in gc. The value-mask and value-list specify which components are to be changed. The 65 X Protocol X11, Release 6.7 DRAFT values and restrictions are the same as for CreateGC. Changing the clip-mask also overrides any previous Set- ClipRectangles request on the context. Changing dash-offset or dashes overrides any previous SetDashes request on the context. The order in which components are verified and altered is server-dependent. If an error is generated, a subset of the components may have been altered. __ | CopyGC src-gc, dst-gc: GCONTEXT value-mask: BITMASK |__ Errors: Alloc, GContext, Match, Value This request copies components from src-gc to dst-gc. The value-mask specifies which components to copy, as for Cre- ateGC. The two gcontexts must have the same root and the same depth (or a Match error results). __ | SetDashes gc: GCONTEXT dash-offset: CARD16 dashes: LISTofCARD8 |__ Errors: Alloc, GContext, Value This request sets dash-offset and dashes in gc for dashed line styles. Dashes cannot be empty (or a Value error results). Specifying an odd-length list is equivalent to specifying the same list concatenated with itself to produce an even-length list. The initial and alternating elements of dashes are the even dashes; the others are the odd dashes. Each element specifies a dash length in pixels. All of the elements must be nonzero (or a Value error results). The dash-offset defines the phase of the pattern, specifying how many pixels into dashes the pattern should actually begin in any single graphics request. Dashing is continuous through path elements combined with a join-style but is reset to the dash-offset between each sequence of joined lines. The unit of measure for dashes is the same as in the ordi- nary coordinate system. Ideally, a dash length is measured 66 X Protocol X11, Release 6.7 DRAFT along the slope of the line, but implementations are only required to match this ideal for horizontal and vertical lines. Failing the ideal semantics, it is suggested that the length be measured along the major axis of the line. The major axis is defined as the x axis for lines drawn at an angle of between -45 and +45 degrees or between 135 and 225 degrees from the x axis. For all other lines, the major axis is the y axis. For any graphics primitive, the computation of the endpoint of an individual dash only depends on the geometry of the primitive, the start position of the dash, the direction of the dash, and the dash length. For any graphics primitive, the total set of pixels used to render the primitive (both even and odd numbered dash ele- ments) with DoubleDash line-style is the same as the set of pixels used to render the primitive with Solid line-style. For any graphics primitive, if the primitive is drawn with O