Try redrawing in multiple phases to avoid blocking the UI thread too long

When initially calling lo_render_windows() from a redrawRect(), just
post the user event asking for a redraw of the (headless) windows, and
return without actually drawing anything to the context.

Then when the RenderWindows() callback for that user event eventually
gets called (which during startup and/or loading of a document might
be several seconds later, as there is lots of other activity going on
also as "user events"), ask the UI thread for a fresh redraw, and wait
for lo_render_windows() in that phase to signal the actual redraw of
the "headless" windows into the context.

Unfortunately this doesn't work well enough. It is not a good idea to
not draw anything in response to a drawRect() it seems. The affected
rectangle gets initialised to black. So there is now irritating
flashing. One sees an almost ready document (and the UI elements which
still are there), but then it goes away for some time before finally
re-appearding. Quite silly. So I will revert this, and I am committing
it just to keep the code for reference in git.

Change-Id: I9ee490345f093d80113c36f9e3268cab5a810dd0

1 files changed, 1 insertions, 0 deletions

diff --git a/ios/experimental/LibreOffice/LibreOffice/AppDelegate.m b/ios/experimental/LibreOffice/LibreOffice/AppDelegate.m
index 2f74d483fb63..8daaccdbc9b1 100644
--- a/ios/experimental/LibreOffice/LibreOffice/AppDelegate.m
+++ b/ios/experimental/LibreOffice/LibreOffice/AppDelegate.m
@@ -37,6 +37,7 @@ static UIView *theView;
     r.origin = CGPointMake(0, 0);
 
     self.view = [[View alloc] initWithFrame: r];
+    self.view.clearsContextBeforeDrawing = NO;
     vc.view = self.view;
     theView = self.view;