It is possible for a PaintTask to start exiting soon after sending new
buffers to the compositor. In that case, the compositor should return
the now unnecessary buffers to the PaintTask so that it can properly
free them.
To accomplish this, the compositor now keeps a hash map of paint task
channels per pipeline id. When a PaintTask exists, the constellation
informs the compositor that it can forget about it. Additionally, the
PaintTask should not wait for any buffers when the engine is doing a
complete shutdown. In that case, the compositor is already halted and
has simply let all buffers leak. We pipe through the shutdown type when
destroying the pipeline to make this decision.
Fixes#2641.
When finding the layer under a point, take into account clipping
rectangles defined by layers that mask to bounds. This prevents clicks
from being hijacked by masked layers.
Root layers that define the extent of iframes should always mask their
child content. This fixes a bug where root layers without an assigned
size and location do not spill over the entire scene.
Instead of creating a display list for the entire page, only create one
for an area that expands around the viewport. On my machine this makes
incremental layout of http://timecube.com 50% faster.
This allows the compositor to add frames after the call to SetIds,
where the initial frame tree is created. There are still some issues
preventing proper late frame creation, but this prevents crashes when
it happens.
Fixes#3738.
Instead of creating a display list for the entire page, only create one
for an area that expands around the viewport. On my machine this makes
incremental layout of http://timecube.com 50% faster.
Now that scrolling roots are properly sized, we can simply look at the
scrolling root layer size when deciding the extents of layer scrolling.
This simplifies things a bit and further codifies the current model of
scrolling root + mask_to_bounds.
When interacting with Layers it is simpler to use LayerPixels, which
are unscaled pixels in the Layer coordinate system. This removes a lot
of room for error and makes things simpler.
Base layers (the background layer of each frame) shouldn't override the
size of their root layers. This allows base layers to scroll inside
root layer frames. This does mean that when determining the maximum
scroll position, we need to look at the size of scrolling root children
though.
Root layers should be sized to their frame rectangles and the root of
the root layers should track the window size. This is important because
layers need to be properly sized to scroll.
This allows iframe layers to move properly when their parents scroll
and is necessary to properly track their masking rects as their
children move and to draw their backgrounds in the proper position.
