X11

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The X11 package contains some units which contain the translations of the X header files.

List of units

The most basic units are:

  • X basic X routines.
  • xcms Some color management.
  • xlib Xlib toolkit.
  • xrender X Render extension.
  • xresource X resource management.
  • xshm X shared memory extension.
  • xutil X util lib.

Newer units:

  • cursorfont
  • xinerama
  • xrandr
  • keysym
  • xf86dga.pp
  • xkb
  • xv
  • xf86vmode
  • xkblib
  • xvlib
  • xatom
  • xi

All these units link to the various X libraries. These units interface to the documented client libraries, and are thus largely immune to the X11<->Xorg changes.

Examples

A window with a message

This is a very simple application which show a window with a written message.

program xshowwindow;
 
{$mode objfpc}{$H+}
 
uses
  xlib, x, ctypes;
 
procedure ModalShowX11Window(AMsg: string);
var
  d: PDisplay;
  w: TWindow;
  e: TXEvent;
  msg: PChar;
  s: cint;
begin
  msg := PChar(AMsg);
 
  { open connection with the server }
  d := XOpenDisplay(nil);
  if (d = nil) then
  begin
    WriteLn('[ModalShowX11Window] Cannot open display');
    exit;
  end;
 
  s := DefaultScreen(d);
 
  { create window }
  w := XCreateSimpleWindow(d, RootWindow(d, s), 10, 10, 200, 200, 1,
                           BlackPixel(d, s), WhitePixel(d, s));
 
  { select kind of events we are interested in }
  XSelectInput(d, w, ExposureMask or KeyPressMask);
 
  { map (show) the window }
  XMapWindow(d, w);
 
  { event loop }
  while (True) do
  begin
    XNextEvent(d, @e);
    { draw or redraw the window }
    if (e._type = Expose) then
    begin
      XFillRectangle(d, w, DefaultGC(d, s), 20, 20, 10, 10);
      XDrawString(d, w, DefaultGC(d, s), 50, 50, msg, strlen(msg));
    end;
    { exit on key press }
    if (e._type = KeyPress) then Break;
  end;
 
  { close connection to server }
  XCloseDisplay(d);
end;
 
begin
  ModalShowX11Window('My message');
end.

See Also

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