SurfaceFlinger: add a crop to the layer state

This change adds a crop rectangle specified in window coordinates to the layer
state.  The all window pixels outside this crop rectangle are treated as though
they were fully transparent.  This change also adds the plumbing necessary for
WindowManager to set that crop.

Change-Id: I582bc445dc8c97d4c943d4db8d582a6ef5a66081

1 files changed, 17 insertions, 0 deletions

diff --git a/libs/gui/SurfaceComposerClient.cpp b/libs/gui/SurfaceComposerClient.cpp
index ceb1ba6..8fa2167 100644
--- a/libs/gui/SurfaceComposerClient.cpp
+++ b/libs/gui/SurfaceComposerClient.cpp
@@ -125,6 +125,8 @@ public:
             const sp<SurfaceComposerClient>& client, SurfaceID id,
             uint32_t tint);
     status_t setOrientation(int orientation);
+    status_t setCrop(const sp<SurfaceComposerClient>& client, SurfaceID id,
+            const Rect& crop);
 
     static void closeGlobalTransaction(bool synchronous) {
         Composer::getInstance().closeGlobalTransactionImpl(synchronous);
@@ -290,6 +292,17 @@ status_t Composer::setOrientation(int orientation) {
     return NO_ERROR;
 }
 
+status_t Composer::setCrop(const sp<SurfaceComposerClient>& client,
+        SurfaceID id, const Rect& crop) {
+    Mutex::Autolock _l(mLock);
+    layer_state_t* s = getLayerStateLocked(client, id);
+    if (!s)
+        return BAD_INDEX;
+    s->what |= ISurfaceComposer::eCropChanged;
+    s->crop = crop;
+    return NO_ERROR;
+}
+
 // ---------------------------------------------------------------------------
 
 SurfaceComposerClient::SurfaceComposerClient()
@@ -398,6 +411,10 @@ void SurfaceComposerClient::closeGlobalTransaction(bool synchronous) {
 
 // ----------------------------------------------------------------------------
 
+status_t SurfaceComposerClient::setCrop(SurfaceID id, const Rect& crop) {
+    return getComposer().setCrop(this, id, crop);
+}
+
 status_t SurfaceComposerClient::setFreezeTint(SurfaceID id, uint32_t tint) {
     return getComposer().setFreezeTint(this, id, tint);
 }