[Merge] lp:~albaguirre/qtubuntu/use-mir-surface-apis into lp:qtubuntu

[Daniel d'Andrada]

The proposal to merge lp:~albaguirre/qtubuntu/use-mir-surface-apis into lp:qtubuntu has been updated.

Commit Message changed to:

Add support for Qt popups and dialog windows.

I have done some refactoring, cleanup and some bug fixing.

- An UbuntuWindow internally creates UbuntuSurface
- UbuntuSurface is responsible for creating the mir surfaces and calling mir apis
- Fix mutex locking (now really protecting access to mSurface) was not locked properly (QMutexLocker temporaries were created : QMutexLocker(&d->mutex) instead of QMutexLocker lock(&d->mutex).
- Handling resize events from the server has been improved.
-- Old resize events are dropped - meaning no redraw requests are issued if we know there are newer resize events in the queue
-- Redraw requests are never issued through the rendering thread only through the Qt event dispatch thread.
-- No flushing of event queue which leads to fewer interruptions in other surfaces (specially noticeable on surfaces that do animations).
- Workaround QtCreator not assigning a parent to its menu bar menus
-- The last focused window is tracked and used if a Qt popup is created without a parent
- Client requested resizes (through setGeometry) is now supported
- Resizing constraints are supported (propagateSizeHints)
- Visibility and window state are tracked separately
- Better focusing event handling
-- When an app has multiple windows, mir will send focus lost/gain pairs,
   in which case we need to peek into the queue to avoid telling Qt to unfocus all windows prematurely.

For more details, see:
https://code.launchpad.net/~albaguirre/qtubuntu/use-mir-surface-apis/+merge/267228
-- 
Your team Ubuntu Phablet Team is subscribed to branch lp:qtubuntu.