Gecko:DisplayListBasedInvalidation: Difference between revisions

Gecko:DisplayListBasedInvalidation (view source)

224 bytes added , 4 October 2012

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 Used to find changes in inactive layer trees, compute widget dirty rects (BasicLayers only) and report MozAfterPaint events.
-= Potential Problems =
+= Implementor Notes =
-* Window resizing / incremental loading
+* DLBI assumes that each frame builds display items for its own content. If changes to a frame are reflected in the display item of a different, then you need to make sure that either the display item's ComputeInvalidationRegion implementation knows to check for this, or propagate InvalidateFrame() calls up to the drawing frame.
-** We want to make sure that we are only invalidating the new areas, not the entire page
-* Bordered frame size changes
-** We don't really want to invalidate the entire area here, but we do need to invalidate some of the internal area as well as the extended bounds.
+* If you're adding a new display item class, you may want to implement AllocateGeometry/ComputeInvalidationRegion and add a new nsDisplayItemGeometry subclass. Or the provided defaults may work fine.
 = Debugging Invalidations Problems =