[alove] 18 Oct 2004 -  This page illustrates a couple ways to create full-screen toplevel windows.  I wrote these for Windows XP, but the bottom one is confirmed to work for Linux too.  If someone can tell me how to zoom a window in other OS versions, please let me know.


 package require Tcl 8.4
 
 wm title . "Full-screen with decorations"
 set a [expr {int([winfo screenwidth .] * 0.5)}]
 set b [expr {int([winfo screenheight .] * 0.5)}]
 wm geometry . 400x300+[expr $a - 200]+[expr $b - 150]  ;# window is centered
 update idletasks 
 wm attributes . -topmost no
 wm state . zoomed  ;# This command for Windows only
 
 frame .x -highlightthickness 0 -bg #c8efff
 place .x -x 0 -y 0 -relwidth 1 -relheight 1

 bind . <KeyPress-Escape> "wm iconify ."
 
[alove] 11 Oct 2004 - This one has no decorations.  
  
 package require Tcl 8.4

 wm title . "Full-screen with NO decorations"
 wm overrideredirect . yes      ;# removes window decorations
 wm geometry . [winfo screenwidth .]x[winfo screenheight .]+0+0
 update idletasks               ;# updates the full-screen
 wm attributes . -topmost yes   ;# stays on top - needed for Linux
                                ;# on Win9x, if =no, alt-tab will malfunction
 frame .x -highlightthickness 0 -bg #c8efff
 place .x -x 0 -y 0 -relwidth 1 -relheight 1

 button .x.min -text "Minimize" -bg #ffdbff -font "arial 10 bold" \
    -command x_iconify
 place  .x.min -x [expr [winfo screenwidth  .] - 140] -y 10

 button .x.end -text "Close" -bg #ffdbff -font "arial 10 bold" \
    -command "destroy ."
 place  .x.end -x [expr [winfo screenwidth  .] - 60] -y 10

 bind . <Expose> "wm overrideredirect . yes; focus -force ."
 bind . <KeyPress-Escape> x_iconify

 proc x_iconify {} {
 wm overrideredirect . no
 wm iconify .
 }

This one works on WindowsXP, probably Win9x, and according to [rdt], now also on Linux. Just click on the "minimize" button or the <Escape> key. The trick is to use <Expose> to detect that the window is being deiconified. The "focus force ." is necessary for Windows, otherwise the <escape> doesn't work until you click on the window first.

Adam Love
--

[rdt] says on Linux, this works if the 'wm overrideredirect ...' comes before the 'wm geometry ...' if the 'wm attributes ...' is commented out it gives an error.

[alove] Thanks, I've corrected the code above.  NOTE: If you set topmost=no, you will have problems with alt-tab on Windows - the icon will disappear and you can only close the program via the task manager (end task).

(question by Andy M) Tried this on Fedora Core 2 Linux, but I lose focus after running overrideredirect, and the bind . <Expose> above doesn't seem to get it back.  Keyboard input doesn't get directed to my script now, but I have some timers that still cycle, so I know the script isn't hung, and without the overrideredirect, the script runs ok.  Tried "focus -force .", but the wm has lost control of the window.  Suggestions?

---

[SC] Tried this on my two-screen xinerama linux setup and of course the window spans 'both' screens. A little
bit of digging reveals the culprit as the X11 WidthOfScreen macro and a little more reveals that finding
the true width of the screen isn't that hard. Here's a little bit of C code as memo of how it might be
done:

 /* screen-info.c
  *
  * Compile with:
  *   cc -o screen-info screen-info.c -I/usr/X11R6/include -L/usr/X11R6/lib -lXinerama -lX11 -lXext
  *
  */

 #include <stdio.h>
 #include <unistd.h>
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
 #include <X11/extensions/Xinerama.h>

 int main(int argc, char *argv[]) {
     Display *display;
     Screen *screen;
     int i;

     display = XOpenDisplay(NULL);
     if(!display) {
	 printf("Couldn't open display %s\n",display);
     }

     if ( XineramaIsActive( display ) ) {
       int nscreens;
       XineramaScreenInfo * info = XineramaQueryScreens( display, &nscreens );

       printf("Xinerama is active\n");

       for( i = 0; i< nscreens; i++ ) {
	 printf( "Screen %d: (%d) %d+%d+%dx%d\n", i, info[i].screen_number, 
		 info[i].x_org, info[i].y_org,
		 info[i].width, info[i].height );
       }
     } else {
       printf("Xinerama is not active\n");
     }

     screen = DefaultScreenOfDisplay(display);
     printf( "DefaultScreenOfDisplay, %d x %d\n", 
	     WidthOfScreen(screen), HeightOfScreen(screen) );

     return(0);
 }