[meld: 149/180] sourceview: Update drawing to use cairo clip extents for bounds

[Kai Willadsen <kaiw src gnome org>]

commit 35069302d59176c458494466a8640f0c9e14266b
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Tue Nov 11 06:26:34 2014 +1000

    sourceview: Update drawing to use cairo clip extents for bounds
    
    Previously, we checked to see what portion of the TextView was visible
    when deciding which changes needed redrawing. That doesn't work now
    with the pixel cache, which draws both above and below what's actually
    on screen.
    
    With this change, we trust that the cairo clip extents match up with
    what's going in to the pixel cache, and so use those as bounds for our
    change drawing.

 meld/sourceview.py |   12 +++++++-----
 1 files changed, 7 insertions(+), 5 deletions(-)
---
diff --git a/meld/sourceview.py b/meld/sourceview.py
index cb3f83b..fb0a04f 100644
--- a/meld/sourceview.py
+++ b/meld/sourceview.py
@@ -165,13 +165,15 @@ class MeldSourceView(GtkSource.View):
 
         visible = self.get_visible_rect()
         textbuffer = self.get_buffer()
-        x, y = self.window_to_buffer_coords(
-            Gtk.TextWindowType.WIDGET, 0, 0)
-        view_allocation = self.get_allocation()
+        _, rect = Gdk.cairo_get_clip_rectangle(context)
+        _, y = self.window_to_buffer_coords(
+            Gtk.TextWindowType.WIDGET, 0, rect.y)
+        _, y_end = self.window_to_buffer_coords(
+            Gtk.TextWindowType.WIDGET, 0, rect.y + rect.height)
         bounds = (self.get_line_num_for_y(y),
-                  self.get_line_num_for_y(y + view_allocation.height + 1))
+                  self.get_line_num_for_y(y_end))
 
-        width, height = view_allocation.width, view_allocation.height
+        width = self.get_allocation().width
         context.set_line_width(1.0)
 
         # Paint chunk backgrounds and outlines