Commit c084015e authored May 31, 2023 by Jorge Gil

Reland: Crop surface to the content size during drag-resizing

During drag-resizing, a fullscreen-sized surface is reused to
optimize reallocations, which can leave outdated app content on the
surface when resizing to a smaller size. This outdated app content
can then be briefly exposed to the user when drag-resizing to a
larger size until the app draws again and fills the new size.
To "clear" this garbage content, this change crops the content
directly from the client side during drag-resizing. The "gap" between
the cropped app content and the larger task that's in sync with the
drag-gesture is now the solid background color of the task surface
instead of the former garbage app content.

Bug: 270202228
Test: quickly drag-resize a freeform task to a smaller and then a
larger size, verify that the "gap" exposed while the app draw catches
up to the resize gesture is now a solid color instead of artifacts
from a previous app draw.
Test: atest AutoEnterPipFromSplitScreenOnGoToHomeTest - no regressions

Change-Id: Ibc3ca2a8f5b83b3fef2fe4832f93ca52d3b156a8
(cherry picked from commit 52530935)

parent e9998047

core/java/android/view/ViewRootImpl.java

+14 −4

Original line number	Diff line number	Diff line
		@@ -8432,11 +8432,21 @@ public final class ViewRootImpl implements ViewParent,
		}
		}

		if (mSurfaceControl.isValid() && !HardwareRenderer.isDrawingEnabled()) {
		if (mSurfaceControl.isValid()) {
		if (mPendingDragResizing && !mSurfaceSize.equals(
		mWinFrameInScreen.width(), mWinFrameInScreen.height())) {
		// During drag-resize, a single fullscreen-sized surface is reused for optimization.
		// Crop to the content size instead of the surface size to avoid exposing garbage
		// content that is still on the surface from previous re-layouts (e.g. when
		// resizing to a larger size).
		mTransaction.setWindowCrop(mSurfaceControl,
		mWinFrameInScreen.width(), mWinFrameInScreen.height());
		} else if (!HardwareRenderer.isDrawingEnabled()) {
		// When drawing is disabled the window layer won't have a valid buffer.
		// Set a window crop so input can get delivered to the window.
		mTransaction.setWindowCrop(mSurfaceControl, mSurfaceSize.x, mSurfaceSize.y).apply();
		}
		}

		mLastTransformHint = transformHint;