Maintain Z order for all layers in offscreen hierarchy
There was already code in place to ensure that z order was maintained in
the offscreen tree. However, this didn't work if a layer was moved to become
a child of an offscreen layer. The z order was only maintained beneath
the new offscreen layer, not the entire subtree.
This change uses the root of the offscreen subtree to ensure the z order
is maintained even when new offscreen layers are added to the subtree.
Fixes: 157188227
Test: IME gets correct relative z
Test: RelativeZTest.LayerWithRelativeReparentedToOffscreen
Change-Id: I62553ce245dacd2a8684d8bb02de67f60ddc6774
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index dcc213f..f5acbae 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -229,13 +229,23 @@
mFlinger->markLayerPendingRemovalLocked(this);
}
+sp<Layer> Layer::getRootLayer() {
+ sp<Layer> parent = getParent();
+ if (parent == nullptr) {
+ return this;
+ }
+ return parent->getRootLayer();
+}
+
void Layer::onRemovedFromCurrentState() {
- auto layersInTree = getLayersInTree(LayerVector::StateSet::Current);
+ // Use the root layer since we want to maintain the hierarchy for the entire subtree.
+ auto layersInTree = getRootLayer()->getLayersInTree(LayerVector::StateSet::Current);
std::sort(layersInTree.begin(), layersInTree.end());
- for (const auto& layer : layersInTree) {
+
+ traverse(LayerVector::StateSet::Current, [&](Layer* layer) {
layer->removeFromCurrentState();
layer->removeRelativeZ(layersInTree);
- }
+ });
}
void Layer::addToCurrentState() {
diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index 3fa935f..8507331 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -1088,6 +1088,10 @@
// Find the root of the cloned hierarchy, this means the first non cloned parent.
// This will return null if first non cloned parent is not found.
sp<Layer> getClonedRoot();
+
+ // Finds the top most layer in the hierarchy. This will find the root Layer where the parent is
+ // null.
+ sp<Layer> getRootLayer();
};
} // namespace android
diff --git a/services/surfaceflinger/tests/RelativeZ_test.cpp b/services/surfaceflinger/tests/RelativeZ_test.cpp
index 1180cac..3e0b3c6 100644
--- a/services/surfaceflinger/tests/RelativeZ_test.cpp
+++ b/services/surfaceflinger/tests/RelativeZ_test.cpp
@@ -207,6 +207,71 @@
sc->checkPixel(1, 1, Color::BLUE.r, Color::BLUE.g, Color::BLUE.b);
}
}
+
+// Preserve the relative z order when a layer is reparented to a layer that's already offscreen
+TEST_F(RelativeZTest, LayerWithRelativeReparentedToOffscreen) {
+ std::unique_ptr<ScreenCapture> sc;
+
+ Color testLayerColor = {255, 100, 0, 255};
+
+ // Background layer (RED)
+ // Foregroud layer (GREEN)
+ // child level 1a (testLayerColor) (relative to child level 2b)
+ // child level 1b (WHITE)
+ // child level 2a (BLUE)
+ // child level 2b (BLACK)
+ sp<SurfaceControl> childLevel1a =
+ createColorLayer("child level 1a", testLayerColor, mForegroundLayer.get());
+ sp<SurfaceControl> childLevel1b =
+ createColorLayer("child level 1b", Color::WHITE, mForegroundLayer.get());
+ sp<SurfaceControl> childLevel2a =
+ createColorLayer("child level 2a", Color::BLUE, childLevel1b.get());
+ sp<SurfaceControl> childLevel2b =
+ createColorLayer("child level 2b", Color::BLACK, childLevel1b.get());
+
+ Transaction{}
+ .setRelativeLayer(childLevel1a, childLevel2b->getHandle(), 1)
+ .show(childLevel1a)
+ .show(childLevel1b)
+ .show(childLevel2a)
+ .show(childLevel2b)
+ .apply();
+
+ {
+ // The childLevel1a should be in front of childLevel2b.
+ ScreenCapture::captureScreen(&sc);
+ sc->expectColor(Rect(0, 0, mDisplayWidth, mDisplayHeight), testLayerColor);
+ }
+
+ // Background layer (RED)
+ // Foregroud layer (GREEN)
+ // child level 1a (testLayerColor) (relative to child level 2b)
+ Transaction{}.reparent(childLevel1b, nullptr).apply();
+
+ // // Background layer (RED)
+ // // Foregroud layer (GREEN)
+ Transaction{}.reparent(childLevel1a, childLevel2a->getHandle()).apply();
+
+ {
+ // The childLevel1a and childLevel1b are no longer on screen
+ ScreenCapture::captureScreen(&sc);
+ sc->expectColor(Rect(0, 0, mDisplayWidth, mDisplayHeight), Color::GREEN);
+ }
+
+ // Background layer (RED)
+ // Foregroud layer (GREEN)
+ // child level 1b (WHITE)
+ // child level 2a (BLUE)
+ // child level 1a (testLayerColor) (relative to child level 2b)
+ // child level 2b (BLACK)
+ Transaction{}.reparent(childLevel1b, mForegroundLayer->getHandle()).apply();
+
+ {
+ // Nothing should change at this point since relative z info was preserved.
+ ScreenCapture::captureScreen(&sc);
+ sc->expectColor(Rect(0, 0, mDisplayWidth, mDisplayHeight), testLayerColor);
+ }
+}
} // namespace android
// TODO(b/129481165): remove the #pragma below and fix conversion issues