commit afd527ab1d841df22073f3b8c77ac3349c0e49e1
author Vishnu Nair <vishnun@google.com> Tue Oct 18 08:56:10 2022 -0700
committer Vishnu Nair <vishnun@google.com> Tue Oct 18 16:26:49 2022 +0000
tree 121bffd0f2c5e4a3fbad4bea546a64dc8f8349e1
parent 22c43f5828ea5b995f699f13246ed323539e9575

SF: Update transform hint when reparenting layers

A layer might be reparented to another display. When that
happens, update the transform hint for the layer.

Also, use the correct display when creating a layer.

Bug: 251360251
Test: move app between displays, rotate, check final buffer transforms
Change-Id: I742c15319d09804a5d7a4c1aac383893d7a67d53

services/surfaceflinger/SurfaceFlinger.cpp

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index a04ceef..e0119be 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -84,6 +84,7 @@
 #include <ui/DisplayState.h>
 #include <ui/DynamicDisplayInfo.h>
 #include <ui/GraphicBufferAllocator.h>
+#include <ui/LayerStack.h>
 #include <ui/PixelFormat.h>
 #include <ui/StaticDisplayInfo.h>
 #include <utils/StopWatch.h>
@@ -4116,6 +4117,8 @@
         return 0;
     }
 
+    ui::LayerStack oldLayerStack = layer->getLayerStack();
+
     // Only set by BLAST adapter layers
     if (what & layer_state_t::eProducerDisconnect) {
         layer->onDisconnect();
@@ -4380,6 +4383,12 @@
     if (layer->setTransactionCompletedListeners(callbackHandles)) flags |= eTraversalNeeded;
     // Do not put anything that updates layer state or modifies flags after
     // setTransactionCompletedListener
+
+    // if the layer has been parented on to a new display, update its transform hint.
+    if (((flags & eTransformHintUpdateNeeded) == 0) && oldLayerStack != layer->getLayerStack()) {
+        flags |= eTransformHintUpdateNeeded;
+    }
+
     return flags;
 }
 
@@ -6876,7 +6885,20 @@
         parent->addChild(layer);
     }
 
-    layer->updateTransformHint(mActiveDisplayTransformHint);
+    ui::LayerStack layerStack = layer->getLayerStack();
+    sp<const DisplayDevice> hintDisplay;
+    // Find the display that includes the layer.
+    for (const auto& [token, display] : mDisplays) {
+        if (display->getLayerStack() == layerStack) {
+            hintDisplay = display;
+            break;
+        }
+    }
+
+    if (hintDisplay) {
+        layer->updateTransformHint(hintDisplay->getTransformHint());
+    }
+
     if (mTransactionTracing) {
         mTransactionTracing->onLayerAddedToDrawingState(layer->getSequence(), vsyncId.value);
     }