[compiz] [PATCH] Resize improvements (Multiple resize modes, better aspect ratio constraining)

[Danny Baumann]

Hi,

> 0001-Added-options-for-additional-resize-modes.patch - I think I'll just
> leave this patch out and add these options once we converted the resize
> plugin to use the new metadata system.

Yes, that's ok as it has the same effect ;-)

> 0002-Added-painting-code-for-additional-resize-modes.patch - I think we
> want the paintWindow function to paint it's own instance of the window
> like switcher and scale plugins are doing instead of transforming the
> core instance. The outline drawing is OK.

No big deal, will change that (although I still think that for things
like resizing/minimization we should go with modifying the core instance
because I don't see why we should add a second fake window instance -
but we discussed this earlier ;-) ).

> 0003-Update-resize-logic-to-reflect-additional-resize-mod.patch - I see
> a lot of calls to damageScreen in this patch when damageScreenRegion
> should be used in all those cases to avoid redrawing more than we need.
> Motion events shouldn't cause the window to be move when resizing in
> stretch-mode and rightEdge, bottomEdge variables can be removed once
> that's changed.

So you mean the window should just be translated in stretch mode? That
makes a lot of sense, right. You're also right about the damageScreen
calls (I don't think the difference will be huge as these calls are
executed very rarely, but I get your point).

> 0004-Added-proper-constraining-code.patch - I hope we can avoid
> including all this code and instead improve the core constraint function
> to solve any problems that currently exist. Can you provide some details
> on how the constraining is not currently working properly in the resize
> plugin so we can discuss how to best solve that?

The main point the current constraining code is lacking are the
following:

1) ability to apply only a subset of all the constraints (e.g. only
applying minimum/maximum size constraints) - no big deal with passing a
bit mask to constrainNewWindowSize

2) abilitity to resize windows with aspect ratio hint set to other
directions than the lower right 
The code in the patch (which was taken from Metacity) takes the resize
direction into account in order to compute the best possible window size
depending on the resize direction. The problem that I see here is: how
to pass the direction of resizing to constrainNewWindowSize properly?
Perhaps we could pass it using an enum and assume some default behaviour
when there is no clear direction (e.g. when called from
addWindowSizeChanges).

> 0005-Warp-pointer-if-resizing-hit-constraints-to-avoid-mo.patch - I had
> something similar to this in the resize plugin before but removed it as
> it can't be done properly, it will always look bad as the cursor can
> never be constrained perfectly. I'd like to avoid this completely.

Ok.

> 0006-Added-screen-damages-which-were-missing-if-the-resiz.patch - Again,
> damageScreen should never have to be called. You want to use
> damageScreenRegion.

Right, will update this.

> 0007-Avoid-resizing-windows-to-negative-sizes.patch - The constrain size
> code should be fixed to take care of this if it doesn't already.

It does, but there is some weird effect when only one coordinate is
negative. In my testing, the size (-1|700) became something like (20|
20). I will have a look into this if there is a more appropriate
solution than that patch.

> 0008-Avoid-window-flashing-back-to-its-old-size-for-a-sho.patch - Does
> this have to be a special case? Can't we have the final size change
> always be the indication that the resizing is done (not only for stretch
> mode)?

I'm not sure if I completely got your question, but the problem is as
follows: 
-  resize done 
-> configureXWindow is called 
-> server information is updated 
-> ... (server processing) 
-> (drawing during that time using the not updated w->attrib
coordinates) 
-> server processing finished, resizeWindow is called, w->attrib is
updated

If you have any suggestion on how to avoid that flashing back during the
server round trip, please let me know.

Regards,

Danny