SurfaceFlinger and libgui: Support for child layers.

Add support for parenting Layers in a tree. Layers
follow scene-graph style rules, that is to say:
   1. A child is cropped to the final bounds of the parent.
   2. A child inherits the parent's transform (including position)
   3. A child's Z ordering is relative to the parent and bounded between
      the parents siblings.
   4. A childs lifetime is bounded by it's parents lifetime.

Test: New tests in Transaction_test plus manual testing with later branches.
Change-Id: I96f8ad863665b9a70b6f845561344c297b7e6eff

1 files changed, 8 insertions, 2 deletions

diff --git a/libs/gui/SurfaceComposerClient.cpp b/libs/gui/SurfaceComposerClient.cpp
index 540dbd9238..c2be6eb751 100644
--- a/libs/gui/SurfaceComposerClient.cpp
+++ b/libs/gui/SurfaceComposerClient.cpp
@@ -610,13 +610,19 @@ sp<SurfaceControl> SurfaceComposerClient::createSurface(
         uint32_t w,
         uint32_t h,
         PixelFormat format,
-        uint32_t flags)
+        uint32_t flags,
+        SurfaceControl* parent)
 {
     sp<SurfaceControl> sur;
     if (mStatus == NO_ERROR) {
         sp<IBinder> handle;
+        sp<IBinder> parentHandle;
         sp<IGraphicBufferProducer> gbp;
-        status_t err = mClient->createSurface(name, w, h, format, flags,
+
+        if (parent != nullptr) {
+            parentHandle = parent->getHandle();
+        }
+        status_t err = mClient->createSurface(name, w, h, format, flags, parentHandle,
                 &handle, &gbp);
         ALOGE_IF(err, "SurfaceComposerClient::createSurface error %s", strerror(-err));
         if (err == NO_ERROR) {