rfc1013.txt

著名的RFC文档,其中有一些文档是已经翻译成中文的的.

   Event sychronization
           There are certain race conditions possible when
           demultiplexing device events to clients (in particular
           deciding where pointer and keyboard events should be sent
           when in the middle of window management operations).  The
           event synchronization mechanism allows synchronous processing
           of device events.





M.I.T.                                                          [Page 6]

RFC 1013                                                       June 1987


   Event propagation
           Device-related events "propagate" from the source window to
           ancestor windows until some client has expressed interest in
           handling that type of event, or until the event is discarded
           explicitly.

   Event source
           The smallest window containing the pointer is the "source"
           of a device related event.

   Exposure event
           Servers do not guarantee to preserve the contents of windows
           when windows are obscured or reconfigur contents of regions
           of windows have been lost.

   Extension
           Named "extensions" to the core protocol can be defined to
           extend the system.  Extension to output requests, resources,
           and event types are all possible, and expected.

   Font
           A "font" is an array of glyphs (typically characters).  The
           protocol does no translation or interpretation of character
           sets.  The client simply indicates values used to index the
           glyph array.  A font contains additional metric information
           to determine inter-glyph and inter-line spacing.

   Glyph
           A "glyph" is an image, typically of a character, in a font.

   Grab
           Keyboard keys, the keyboard, pointer buttons, the pointer,
           and the server can be "grabbed" for exclusive use by a
           client.  In general, these facilities are not intended to be
           used by normal applications, but are intended for various
           input and window managers to implement various styles of
           user interfaces.

   Graphics context
           Various information for graphics output is stored in "GC"'s,
           such as foreground pixel, background pixel, line width,
           clipping region, etc.

   Hotspot
           A cursor has an associated "hot spot" which defines a point
           in the cursor that corresponds to the coordinates reported
           for the pointer.

   Identifier
           Each resource has an "identifier", a unique value associated
           with it that clients use to name the resource.  An identifier



M.I.T.                                                          [Page 7]

RFC 1013                                                       June 1987


           can be used over any connection to name the resource.

   Inferiors
           The "inferiors" of a window are all of the subwindows nested
           below it: the children, the children's children, etc.

   Input focus
           The "input focus" is nominally where keyboard input goes.
           Keyboard events are by default sent to the client expressing
           interest on the window the pointer is in.  This is said to be
           a "real estate driven" input focus.  It is also possible to
           attach the keyboard input to a  specific window; events will
           then be sent to the appropriate client independent of the
           pointer position.

   Input manager
           Control over keyboard input is typically provided by an
           "input manager" client.

   InputOnly window
           A window that cannot be used for graphics requests.
           InputOnly windows are "invisible", and can be used to control
           such things as cursors, input event generation, and grabbing.

   InputOutput window
           The "normal" kind of opaque window, used for both input
           and output.

   Key grabbing
           Keys on the keyboard may be passively "grabbed" by a client.
           When the key is pressed, the keyboard is then actively
           grabbed by the client.

   Keyboard grabbing
           A client can actively "grab" control of the keyboard, and key
           events will be sent to that client rather than the client the
           events would normally have been sent to.

   Mapping
           A window is said to be "mapped" if a map call has been
           performed on it.  Unmapped windows are never viewable or
           visible.

   Modifier keys
           Shift, Control, Meta, Super, Hyper, ALT, Compose, Apple,
           CapsLock, ShiftLock, and similar keys are called "modifier"
           keys.

   Obscures
           Window A "obscures" window B if both are viewable
           InputOutput windows and A is higher in the global stacking



M.I.T.                                                          [Page 8]

RFC 1013                                                       June 1987


           order, and the rectangle defined by the outside edges of
           intersects the rectangle defined by the outside edges of B.
           Note the (fine) distinction with "occludes". Also note that
           window borders are included in the calculation.

   Occludes
           Window A "occludes" window B if both are mapped and A is
           higher in the global stacking order, and the rectangle
           defined by the outside edges of A intersects the rectangle
           defined by the outside edges of B.  Note the (fine)
           distinction with "obscures".  Also note that window borders
           are included in the calculation.

   Padding
           Some padding bytes are inserted in the data stream to
           maintain alignment of the protocol requests on natural
           boundaries.  This increases ease of portability to some
           machine architectures.

   Parent window
           If C is a child of P, then P is the "parent" of C.

   Passive grab
           Grabbing a key or button is a "passive" grab.  The grab
           activates when the key or button is actually pressed.

   Pixel value
           A "pixel" is an N-bit value, where N is the number of bit
           planes used in a particular window or pixmap.  For a window,
           a pixel value indexes a colormap to derive an actual color
           to be displayed.

   Pixmap
           A "pixmap" is a three dimensional array of bits.  A pixmap
           is normally thought of as a two dimensional array of pixels,
           where each pixel can be a value from 0 to (2^N)-1, where N
           is the depth (z axis) of the pixmap.  A pixmap can also be
           thought of as a stack of N bitmaps.

   Plane mask
           Graphics operations can be restricted to only affect a
           subset of bit planes of a destination.  A "plane mask" is
           a bit mask describing which planes are to be modified, and
           is stored in a graphics context.

   Pointer
           The "pointer" is the pointing device attached to the cursor,
           and tracked on the screens.

   Pointer grabbing
           A client can actively "grab" control of the pointer, and



M.I.T.                                                          [Page 9]

RFC 1013                                                       June 1987


           button and motion events will be sent to that client rather
           than the client the events would normally have been sent to.

   Pointing device
           A "pointing device" is typically a mouse or tablet, or some
           other device with effective dimensional motion.  There is
           only one visible cursor is defined by the core protocol,
           and it tracks whatever pointing device is attached as the
           pointer.

   Property
           Windows may have associated "properties", consisting of a
           name, a type, a data format, and some data.  The protocol
           places no interpretation on properties, they are intended
           as a general-purpose naming mechanism for clients.  For
           example, clients might share information such as resize
           hints, program names, and icon formats with a window
           manager via properties.

   Property list
           The "property list" of a window is the list of properties
           that have been defined for the window.

   Redirecting control
           Window managers (or client programs) may wish to enforce
            window layout policy in various ways.  When a client
           attempts to change the size or position of a window, the
           operation may be "redirected" to a specified client,
           rather than the operation actually being performed.

   Reply
           Information requested by a client program is sent back to
           the client with a "reply".  Both events and replys are
           multipexed on the same connection.  Most requests do not
           generate replies.

   Request
           A command to the server is called a "request".  It is a
           single block of data sent over a connection.

   Resource
           Windows, pixmaps, cursors, fonts, graphics contexts, and
           colormaps are known as "resources".  They all have unique
           identifiers associated with them for naming purposes.  The
           lifetime of a resource is bounded by the lifetime of the
           connection over which the resource was created.

   Root
           The "root" of a pixmap or gcontext is the same as the root
           of whatever drawable was used when the pixmap or gcontext
           was created.  The "root" of a window is the root window



M.I.T.                                                         [Page 10]

RFC 1013                                                       June 1987


           under which the window was created.

   Root window
           Each screen has a "root window" covering it.  It cannot be
           reconfigured or unmapped, but otherwise acts as a full
           fledged window. A root window has no parent.

   Save set
           The "save set" of a client is a list of other client's
           windows which, if they are inferiors of one of the client's
           windows at connection close, should not be destroyed, and
           which should be remapped if it is unmapped.  Save sets are
           typically used by window managers to avoid lost windows if
           the manager should terminate abnormally.

   Screen
           A server may provide several independent "screens", which
           typically have physically independent monitors.  This would
           be the expected configuration when there is only a single
           keyboard and pointer shared among the screens.

   Server
           The "server" provides the basic windowing mechanism.  It
           handles IPC connections from clients, demultipexes graphics
           requests onto the screens, and multiplexes input back to the
           appropriate clients.

   Server grabbing
           The server can be "grabbed" by a single client for exclusive
           use. This prevents processing of any requests from other
           client connections until the grab is complete.  This is
           typically only a transient state for such things as
           rubber-banding and pop-up menus, or to execute requests
           indivisibly.

   Sibling
           Children of the same parent window are known as "sibling"
           windows.

   Stacking order
           Sibling windows may "stack" on top of each other.  Windows
           above both obscure and occlude lower windows.  This is
           similar to paper on a desk. The relationship between
           sibling windows is known as the "stacking order".

   Stipple
           A "stipple pattern" is a bitmap that is used to tile a
           region to serve as an additional clip mask for a fill
           operation with the foreground color.





M.I.T.                                                         [Page 11]

RFC 1013                                                       June 1987


   Tile
           A pixmap can be replicated in two dimensions to "tile"
           a region.  The pixmap itself is also known as a "tile".

   Timestamp
           A time value, expressed in milliseconds, typically since
           the last server reset.  Timestamp values wrap around (after
           about 49.7 days). The server, given its current time is
           represented by timestamp T, always interprets timestamps
           from clients by treating half of the timestamp space as
           being earlier in time than T, and half of the timestamp
           space as being later in time than T.  One timestamp value
           (named CurrentTime) is never generated by the server;
           this value is reserved for use in requests to represent
           the current server time.

   Type
           A type is an arbitrary atom used to identify the
           interpretation of property data.  Types are completely
           uninterpreted by the server; they are solely for the
           benefit of clients.

   Unviewable
           A window is "unviewable" if it is mapped but some ancestor is
           unmapped.