Windows jump about under new multiple screen support

[bdeb@…]

The new multiple screen support is great, but:

Set up two displays so that the primary screen has a longer y dimension than the secondary screen, and both are aligned at the bottom. The secondary screen should be on the left. Create a non-X11 window that fills the primary screen. Drag it leftwards so it starts going off the primary screen. Part of the window is now invisible. Now do the same for an X11 window. One pixel BEFORE the window starts to leave the primary display, it jumps down so its title bar is at the top of the secondary display. Two things to observe:

• The window shouldn't jump at all - it should just go offscreen, like other non-X11 windows
• It certainly shouldn't do it one pixel early, when the whole window is actually still on the primary display.

Similar problems may occur for other screen arrangements, too.

[jeremyhu@…]

I don't really think this will be easy to accomplish. The window placement models are in conflict. The X server just handles it differently than the Window Server. I'm not even really sure where in the code the X server handles this, but I'll look into it.

[bdeb@…]

Ah, that seems very reasonable (and it would seem reasonable not to change the behaviour, as it might disconcert the hardcore X11-ers). However, I think it would be worth considering fixing the one-pixel error, as it leads to surprising leaping about of windows if you try to make a window completely fill one screen.

[bdeb@…]

Cc Me!