commit 866455f07c21964af5c195709bc2081121965200
author Robert Carr <racarr@google.com> Tue Apr 02 16:28:26 2019 -0700
committer Robert Carr <racarr@google.com> Thu Apr 04 09:28:42 2019 -0700
tree 42ebce28d4caf7803a9562742bd9013d5828880e
parent 7b5d9813aacda610b262d6773f13a21ba8a75b98

SurfaceFlinger: Add exclusion list for captureLayers.

Among other use cases, WM needs to be able to omit the IME from Task Snapshots,
even while it is on-screen.

Bug: 126614127
Test: Transaction_test.cpp#CaptureLayerExclude,CaptureLayerExcludeTree
Change-Id: I055d99106c9ce2ed90d64eca06961d88cbd5e2d4

services/surfaceflinger/SurfaceFlinger.cpp

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 5676c59..fccd910 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -5405,10 +5405,11 @@
                                useIdentityTransform);
 }
 
-status_t SurfaceFlinger::captureLayers(const sp<IBinder>& layerHandleBinder,
-                                       sp<GraphicBuffer>* outBuffer, const Dataspace reqDataspace,
-                                       const ui::PixelFormat reqPixelFormat, const Rect& sourceCrop,
-                                       float frameScale, bool childrenOnly) {
+status_t SurfaceFlinger::captureLayers(
+        const sp<IBinder>& layerHandleBinder, sp<GraphicBuffer>* outBuffer,
+        const Dataspace reqDataspace, const ui::PixelFormat reqPixelFormat, const Rect& sourceCrop,
+        const std::unordered_set<sp<IBinder>, ISurfaceComposer::SpHash<IBinder>>& excludeHandles,
+        float frameScale, bool childrenOnly) {
     ATRACE_CALL();
 
     class LayerRenderArea : public RenderArea {
@@ -5530,15 +5531,36 @@
         reqHeight = 1;
     }
 
-    LayerRenderArea renderArea(this, parent, crop, reqWidth, reqHeight, reqDataspace, childrenOnly);
+    std::unordered_set<sp<Layer>, ISurfaceComposer::SpHash<Layer>> excludeLayers;
+    for (const auto& handle : excludeHandles) {
+        BBinder* local = handle->localBinder();
+        if (local != nullptr) {
+            auto layerHandle = reinterpret_cast<Layer::Handle*>(local);
+            excludeLayers.emplace(layerHandle->owner.promote());
+        } else {
+            ALOGW("Invalid layer handle passed as excludeLayer to captureLayers");
+            return NAME_NOT_FOUND;
+        }
+    }
 
-    auto traverseLayers = [parent, childrenOnly](const LayerVector::Visitor& visitor) {
+    LayerRenderArea renderArea(this, parent, crop, reqWidth, reqHeight, reqDataspace, childrenOnly);
+    auto traverseLayers = [parent, childrenOnly,
+                           &excludeLayers](const LayerVector::Visitor& visitor) {
         parent->traverseChildrenInZOrder(LayerVector::StateSet::Drawing, [&](Layer* layer) {
             if (!layer->isVisible()) {
                 return;
             } else if (childrenOnly && layer == parent.get()) {
                 return;
             }
+
+            sp<Layer> p = layer;
+            while (p != nullptr) {
+                if (excludeLayers.count(p) != 0) {
+                    return;
+                }
+                p = p->getParent();
+            }
+
             visitor(layer);
         });
     };