Apparently you can't use opengl calls in a configure event signaled from
the window. If you do, on ubuntu 14.04 with unity, each and every frame
will be drawn. Since they are drawn slower than the event are emitted,
it continues to redraw after the resize is done, 'replaying' the resize
motion.
opengl calls from a configure event on the single child of the
window are ok.
Also, now that the window is not used to draw opengl, it doesn't produce
expose events, instead the drawable child must be used.
This also makes moving the window much smoother.
what now happens is that configure events are skipped until the first
on-map signal is fired. seem to work fine in a variety of wm:s. if this
works well we can return active? to be plain boolean.
A UI backend can delay setting active? to 100 until the windows actually
is visible. That way, some redundant redraws that happen when the window
isn't visible is supressed. It makes the Windows and GTK UI startup a
little faster.
Jon Harper
Björn Lindqvist
John Benediktsson