Window listing and manipulating windows in workbench 3.x

[edmayn]

Interesting ...

I now need to determine if a WA_BACKDROP/WLFG_BACKDROP flag is set for a window.

[Daedalus]

Originally Posted by edmayn

I now need to determine if a WA_BACKDROP/WLFG_BACKDROP flag is set for a window.

No you don't, just check that window->Title isn't null (which is good practice for dealing with any pointers anyway, but especially when dealing with the OS, which often uses null as a a legitimate status or result).

[bubbob42]

Originally Posted by edmayn

Interesting ...

I now need to determine if a WA_BACKDROP/WLFG_BACKDROP flag is set for a window.

I had the same problem when I wrote WinZoom (http://aminet.net/util/cdity/WinZoom.lha), which seems to already do some of the things you want to achieve.

The checks I currently perform to filter out the Workbench Window are:

NextWindow != NULL

and

NextWindow->Title!=0 (which should also be "NULL")

I also tried

NextWindow->Flags & WFLG_BACKDROP

but that didn't work very well.

Could you describe in more detail what you're trying to achieve? I started out to write a tool which places the active window in the largest free spot on screen - this is where I failed, because the "optimal algorithm" takes 60 seconds on a 060/50 and a FullHD screen, so a heuristic approach would be needed.

Instead I created a solution for cascading, maximizing (full, half, quarter screen), minimizing and iconifying (layersV45) windows. Seems as if we could collaborate on this project, if you'd like to?

[Cylon]

All Workbench windows have a special flag called WA_Workbenchwindow or similar. very easy to filter.

[bubbob42]

Originally Posted by Cylon

All Workbench windows have a special flag called WA_Workbenchwindow or similar. very easy to filter.

Well, all Workbenchwindows have that flag. Not only the main/backdrop window.

And AFAIR some application windows set this flag as well.

[edmayn]

bubbob42: What I am aiming for is to produce is a tiling window manager with features like dwm or XMonad to name a few. I would also like some sort of status bar. I really have no idea if this is even possible with AmigaOS, but so far it has been fun trying. I plan to draw inspiration from two projects above on how to write tiling algorithms. Read more about tiling window managers here

There is windowtiler on aminet already, but no source code is available and I'd like to know how it is done.

Generally speaking I prefer a keyboard controlled tiling wm, since I spend most of work time in a linux cli.

bubbob42, if you're interested in tiling wm's, and WinZoom looks closely related, I'd like to collaborate, but I need to write some more C first. Eventually I will put what I produce on github, perhaps we can take it from there and see if our interests align?

Concerning the window lister thing, I believe I have ironed out the problems pointed out by Thomas. I also found a workaround to Workbench Window/Backdrop problem. I've tried semi-hard to crash the program from different consoles, while running enforcer which gets no hit (is it enough to run it in a separate console?), and the program does not crash.

#include <stdio.h>
#include <string.h>
#include <proto/intuition.h>

int main(void)
{
  struct Screen *screen;

  // Lock workbench screen
  if (screen = LockPubScreen("Workbench")) {
    struct Window *window;
    int winnr = 0;
    char *wintitle;

    // Loop through windows on screen
    for (window = screen->FirstWindow; window; window = window->NextWindow) {
      // Ignore Workbench window, also if its backdropped.
      if (!(window->Flags & BACKDROP)
      && (!stricmp(window->Title, "Workbench") == 0)) {
    if (!window->Title) {
      wintitle = "Unnamed Window";
    } else {
      wintitle = window->Title;
    }
    printf("%s %d\n%s  \"%s\"\n%s %4d\n%s %d\n%s %8d\n%s %8d\n",
           "Window:", winnr,
           "Title:", wintitle,
           "Width:", window->Width,
           "Height:", window->Height,
           "x:", window->LeftEdge, "y:", window->TopEdge);
    // Increment window id
    winnr++;
      }
    }

    // Unlock screen
    UnlockPubScreen(0, screen);
  }

  return 0;
}

[bubbob42]

Originally Posted by edmayn

Generally speaking I prefer a keyboard controlled tiling wm, since I spend most of work time in a linux cli.

That's exactly what WinZoom does. It emulates the Windows-key+Cursor behaviour of Windows 7+ or Gnome, combined with alt-tab window selection. I also hate touching the mouse. :-)

However, it does not provide >2-column or row-tiling like some of the examples you provided.

bubbob42, if you're interested in tiling wm's, and WinZoom looks closely related, I'd like to collaborate, but I need to write some more C first. Eventually I will put what I produce on github, perhaps we can take it from there and see if our interests align?

Of course! Your project is a great opportunity to get into C and learn about Intuition as well.

Some hints (possible spoiler alert ) :

- You will have to build and manage some kind of window list. I use exec lists for this purpose.
- I recommend switching from console output to serial debug kprintf() via debug.lib. Why? Because if you're manipulating windows you did not open yourself, the Commodore way (check example windowtabbing Commodity from AmigaMail/NDK) goes like this:

ilock = LockIBase(0L);       /* lock intuition base */  
 
/* update your window list here, especially check if target window still exists */

Forbid(); /* kill Multitasking */
UnlockIBase(ilock);

/* manipulate the window structure */

Permit(); /* enable Multitasking */

While this approach avoids race conditions with Intuition, it also forbids console output for reasons Thomas described. So serial debug is the only friend left.

[edmayn]

Looks like valuable advice bubbob42! Thank you.

Which led me to this:

https://fs-uae.net/docs/serial-port

Great.

(I do have a working A1200, but I use fs-uae for testing)

[idrougge]

Do note that other windows may also have null titles, e.g. requesters and toolbars.

[Ami]

Originally Posted by edmayn

I'll see what I can do to avoid the deadlock you mention in regards to KingCON (and probably other console handlers).

I'm not sure, try to put printf() after UnlockIBase()

[edmayn]

The last couple of weeks I have dived deeper in to C on the Amiga and it has been fun!

As a way to get more familiar with intuition and how windows are handled within this framework I have expanded the window lister program quite a bit and refactored it.

It now includes a check for (IMO relevant) intuition window flags and automatic padding and sizing, based on the console width, for the output table.



Code:
https://github.com/RasmusEdgar/amiga.../wlist/wlist.c

(I tried to post the code here with code tags, but it somehow gets mangled up)

The code compiles cleanly with both SAS/C

mkmk
smake

and GCC

gcc wlist.c -o wlist -Werror -Wall -s -noixemul

I hope some of you find it interesting.

Critical feedback is welcome.

Br,
edmayn

[a/b]

General c/c++ suggestions:

char *wintitle, bd[3], ac[3], bl[3], wb[3], gz[3], zo[3];
strcpy(ac, "/ac");
strcpy(bl, "/bl");
strcpy(wb, "/wb");
strcpy(gz, "/gz");
strcpy(zo, "/zo");

strcat(flags, zo);

if (!wininfos) {
	free(miscinfo);   //  <= missing, memory leak
	printf("Failed to create window array of structs! Exiting.\n");
	return 1;
    }

if ((printer = printwindows(wininfos, miscinfo)) != 0) {
	free(miscinfo);   //  <= missing, memory leak
	free(wininfos);   //  <= missing, memory leak
	printf("Failed to print windows! Exiting.\n");
	return 1;
    }

You have to allocate 4 bytes for those strings (3 + terminator).
Use strncat instead of strcat to be on the safe(r) side.

Try to use a little different code structure that makes it easier to clean-up partially allocated/initialized stuff. For example, set all pointers/handles/etc. to null/0/..., then at the end, regardless whether you managed to fully initialize everything or not, go through all of them and free/deinitialize those that aren't null/0. That way you also have one common exit point from a function, so it's easier to add new code (otherwise you have to do partial deallocs all over the place).

[edmayn]

Thank you for the feedback a/b. Highly appreciated. Very valid points you raise. I'll look into fixing them the next couple of days.

[edmayn]

I fixed the problems several months ago, did some refactoring of the functions and changed the way I check for window flags. Forgot to update this thread.

You can find the finished code here:
https://github.com/RasmusEdgar/amiga.../wlist/wlist.c