Ensure that DesktopView geometry is updated before notifying of screen geometry changes
Currently updating the DesktopView geometry and emitting signals notifying of changes to screen geometry are connected independently to QScreen::geometryChanged(), while screenGeometry() as well as availableScreenRect() and availableScreenRegion() depend on the DesktopView geometry. The incorrect order of slots being called causes the task manager to behave incorrectly on screen configuration changes, displaying either no windows or windows from a wrong screen. This also affects the desktop pager widget when configured to show the current desktop only.
To fix this, a new signal DesktopView::geometryChanged() is introduced and the lambda notifying of screen geometry changes is connected to this instead.
Edited by Alexander Kandaurov