Table of Contents

## Name

AllPlanes, BlackPixel, WhitePixel, ConnectionNumber, DefaultColormap, DefaultDepth, XListDepths, DefaultGC, DefaultRootWindow, DefaultScreenOfDisplay, DefaultScreen, DefaultVisual, DisplayCells, DisplayPlanes, DisplayString, XMaxRequestSize, XExtendedMaxRequestSize, LastKnownRequestProcessed, NextRequest, ProtocolVersion, ProtocolRevision, QLength, RootWindow, ScreenCount, ScreenOfDisplay, ServerVendor, VendorRelease - Display macros and functions

## Syntax

AllPlanes

BlackPixel(display, screen_number)

WhitePixel(display, screen_number)

ConnectionNumber(display)

DefaultColormap(display, screen_number)

DefaultDepth(display, screen_number)

int *XListDepths(display, screen_number, count_return)
Display *display;
int screen_number;
int *count_return;

DefaultGC(display, screen_number)

DefaultRootWindow(display)

DefaultScreenOfDisplay(display)

DefaultScreen(display)

DefaultVisual(display, screen_number)

DisplayCells(display, screen_number)

DisplayPlanes(display, screen_number)

DisplayString(display)

long XMaxRequestSize(display) `` `` Display *display;

long XExtendedMaxRequestSize(display) `` `` Display *display;

LastKnownRequestProcessed(display)

NextRequest(display)

ProtocolVersion(display)

ProtocolRevision(display)

QLength(display)

RootWindow(display, screen_number)

ScreenCount(display)

ScreenOfDisplay(display, screen_number)

ServerVendor(display)

VendorRelease(display)

## Arguments

display
  Specifies the connection to the X server.
screen_number
  Specifies the appropriate screen number on the host server.
count_return
  Returns the number of depths.

## Description

The AllPlanes macro returns a value with all bits set to 1 suitable for use in a plane argument to a procedure.

The BlackPixel macro returns the black pixel value for the specified screen.

The WhitePixel macro returns the white pixel value for the specified screen.

The ConnectionNumber macro returns a connection number for the specified display.

The DefaultColormap macro returns the default colormap ID for allocation on the specified screen.

The DefaultDepth macro returns the depth (number of planes) of the default root window for the specified screen.

The XListDepths function returns the array of depths that are available on the specified screen. If the specified screen_number is valid and sufficient memory for the array can be allocated, XListDepths sets count_return to the number of available depths. Otherwise, it does not set count_return and returns NULL. To release the memory allocated for the array of depths, use XFree.

The DefaultGC macro returns the default GC for the root window of the specified screen.

The DefaultRootWindow macro returns the root window for the default screen.

The DefaultScreenOfDisplay macro returns the default screen of the specified display.

The DefaultScreen macro returns the default screen number referenced in the XOpenDisplay routine.

The DefaultVisual macro returns the default visual type for the specified screen.

The DisplayCells macro returns the number of entries in the default colormap.

The DisplayPlanes macro returns the depth of the root window of the specified screen.

The DisplayString macro returns the string that was passed to XOpenDisplay when the current display was opened.

The XMaxRequestSize function returns the maximum request size (in 4-byte units) supported by the server without using an extended-length protocol encoding. Single protocol requests to the server can be no larger than this size unless an extended-length protocol encoding is supported by the server. The protocol guarantees the size to be no smaller than 4096 units (16384 bytes). Xlib automatically breaks data up into multiple protocol requests as necessary for the following functions: XDrawPoints, XDrawRectangles, XDrawSegments, XFillArcs, XFillRectangles, and XPutImage.

The XExtendedMaxRequestSize function returns zero if the specified display does not support an extended-length protocol encoding; otherwise, it returns the maximum request size (in 4-byte units) supported by the server using the extended-length encoding. The Xlib functions XDrawLines, XDrawArcs, XFillPolygon, XChangeProperty, XSetClipRectangles, and XSetRegion will use the extended-length encoding as necessary, if supported by the server. Use of the extended-length encoding in other Xlib functions (for example, XDrawPoints, XDrawRectangles, XDrawSegments, XFillArcs, XFillRectangles, XPutImage) is permitted but not required; an Xlib implementation may choose to split the data across multiple smaller requests instead.

The LastKnownRequestProcessed macro extracts the full serial number of the last request known by Xlib to have been processed by the X server.

The NextRequest macro extracts the full serial number that is to be used for the next request.

The ProtocolVersion macro returns the major version number (11) of the X protocol associated with the connected display.

The ProtocolRevision macro returns the minor protocol revision number of the X server.

The QLength macro returns the length of the event queue for the connected display.

The RootWindow macro returns the root window.

The ScreenCount macro returns the number of available screens.

The ScreenOfDisplay macro returns a pointer to the screen of the specified display.

The ServerVendor macro returns a pointer to a null-terminated string that provides some identification of the owner of the X server implementation.

The VendorRelease macro returns a number related to a vendor's release of the X server.

## See Also

BlackPixelOfScreen(3X11) , ImageByteOrder(3X11) , IsCursorKey(3X11) , XOpenDisplay(3X11)
Xlib - C Language X Interface

Table of Contents

- Name
- Syntax
- Arguments
- Description
- See Also