cc: Expose clear and swap on Region

R=danakj@chromium.org
BUG=none


Review URL: https://chromiumcodereview.appspot.com/11368156

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@166866 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 59 insertions, 16 deletions

diff --git a/cc/layer_tree_host_unittest.cc b/cc/layer_tree_host_unittest.cc
index 04cef7f..b8c92c2 100644
--- a/cc/layer_tree_host_unittest.cc
+++ b/cc/layer_tree_host_unittest.cc
@@ -1632,7 +1632,7 @@ public:
     virtual bool drawsContent() const OVERRIDE { return true; }
 
     const Region& occludedScreenSpace() const { return m_occludedScreenSpace; }
-    void clearOccludedScreenSpace() { m_occludedScreenSpace = Region(); }
+    void clearOccludedScreenSpace() { m_occludedScreenSpace.Clear(); }
 
 private:
     TestLayer() : Layer() { }
diff --git a/cc/occlusion_tracker.cc b/cc/occlusion_tracker.cc
index c5f7276..cefcd9d 100644
--- a/cc/occlusion_tracker.cc
+++ b/cc/occlusion_tracker.cc
@@ -111,13 +111,13 @@ void OcclusionTrackerBase<LayerType, RenderSurfaceType>::finishedRenderTarget(co
     // TODO(senorblanco):  Make this smarter for SkImageFilter case:  once
     // SkImageFilters can report affectsOpacity(), call that.
     if (finishedTarget->maskLayer() || !surfaceOpacityKnown(surface) || surface->drawOpacity() < 1 || finishedTarget->filters().hasFilterThatAffectsOpacity() || finishedTarget->filter()) {
-        m_stack.back().occlusionInScreen = Region();
-        m_stack.back().occlusionInTarget = Region();
+        m_stack.back().occlusionInScreen.Clear();
+        m_stack.back().occlusionInTarget.Clear();
     } else {
         if (!surfaceTransformsToTargetKnown(surface))
-            m_stack.back().occlusionInTarget = Region();
+            m_stack.back().occlusionInTarget.Clear();
         if (!surfaceTransformsToScreenKnown(surface))
-            m_stack.back().occlusionInScreen = Region();
+            m_stack.back().occlusionInScreen.Clear();
     }
 }
 
diff --git a/cc/region.cc b/cc/region.cc
index f0fddc5..4167417 100644
--- a/cc/region.cc
+++ b/cc/region.cc
@@ -38,6 +38,14 @@ const Region& Region::operator=(const Region& region) {
   return *this;
 }
 
+void Region::Swap(Region& region) {
+  region.skregion_.swap(skregion_);
+}
+
+void Region::Clear() {
+  skregion_.setEmpty();
+}
+
 bool Region::IsEmpty() const {
   return skregion_.isEmpty();
 }
diff --git a/cc/region.h b/cc/region.h
index 49ad5f3..00e2bd1 100644
--- a/cc/region.h
+++ b/cc/region.h
@@ -24,6 +24,8 @@ class CC_EXPORT Region {
   const Region& operator=(gfx::Rect rect);
   const Region& operator=(const Region& region);
 
+  void Swap(Region& region);
+  void Clear();
   bool IsEmpty() const;
 
   bool Contains(gfx::Point point) const;
diff --git a/cc/region_unittest.cc b/cc/region_unittest.cc
index db0fc3c..ef1d889 100644
--- a/cc/region_unittest.cc
+++ b/cc/region_unittest.cc
@@ -297,54 +297,54 @@ TEST(RegionTest, ContainsRegion) {
   container.Union(gfx::Rect(0, 20, 41, 20));
   TEST_CONTAINS(container, gfx::Rect(5, 5, 30, 30));
 
-  container = Region();
+  container.Clear();
   container.Union(gfx::Rect(0, 0, 10, 10));
   container.Union(gfx::Rect(0, 30, 10, 10));
   container.Union(gfx::Rect(30, 30, 10, 10));
   container.Union(gfx::Rect(30, 0, 10, 10));
   TEST_NO_CONTAINS(container, gfx::Rect(5, 5, 30, 30));
 
-  container = Region();
+  container.Clear();
   container.Union(gfx::Rect(0, 0, 10, 10));
   container.Union(gfx::Rect(0, 30, 10, 10));
   container.Union(gfx::Rect(30, 0, 10, 40));
   TEST_NO_CONTAINS(container, gfx::Rect(5, 5, 30, 30));
 
-  container = Region();
+  container.Clear();
   container.Union(gfx::Rect(30, 0, 10, 10));
   container.Union(gfx::Rect(30, 30, 10, 10));
   container.Union(gfx::Rect(0, 0, 10, 40));
   TEST_NO_CONTAINS(container, gfx::Rect(5, 5, 30, 30));
 
-  container = Region();
+  container.Clear();
   container.Union(gfx::Rect(0, 0, 10, 40));
   container.Union(gfx::Rect(30, 0, 10, 40));
   TEST_NO_CONTAINS(container, gfx::Rect(5, 5, 30, 30));
 
-  container = Region();
+  container.Clear();
   container.Union(gfx::Rect(0, 0, 40, 40));
   TEST_NO_CONTAINS(container, gfx::Rect(10, -1, 20, 10));
 
-  container = Region();
+  container.Clear();
   container.Union(gfx::Rect(0, 0, 40, 40));
   TEST_NO_CONTAINS(container, gfx::Rect(10, 31, 20, 10));
 
-  container = Region();
+  container.Clear();
   container.Union(gfx::Rect(0, 0, 40, 20));
   container.Union(gfx::Rect(0, 20, 41, 20));
   TEST_NO_CONTAINS(container, gfx::Rect(-1, 10, 10, 20));
 
-  container = Region();
+  container.Clear();
   container.Union(gfx::Rect(0, 0, 40, 20));
   container.Union(gfx::Rect(0, 20, 41, 20));
   TEST_NO_CONTAINS(container, gfx::Rect(31, 10, 10, 20));
 
-  container = Region();
+  container.Clear();
   container.Union(gfx::Rect(0, 0, 40, 40));
   container.Subtract(gfx::Rect(0, 20, 60, 0));
   TEST_NO_CONTAINS(container, gfx::Rect(31, 10, 10, 20));
 
-  container = Region();
+  container.Clear();
   container.Union(gfx::Rect(0, 0, 60, 20));
   container.Union(gfx::Rect(30, 20, 10, 20));
   TEST_NO_CONTAINS(container, gfx::Rect(0, 0, 10, 39));
@@ -357,7 +357,7 @@ TEST(RegionTest, ContainsRegion) {
   TEST_NO_CONTAINS(container, gfx::Rect(50, 0, 10, 40));
   TEST_NO_CONTAINS(container, gfx::Rect(51, 0, 10, 41));
 
-  container = Region();
+  container.Clear();
   container.Union(gfx::Rect(30, 0, 10, 20));
   container.Union(gfx::Rect(0, 20, 60, 20));
   TEST_NO_CONTAINS(container, gfx::Rect(0, 0, 10, 39));
@@ -420,4 +420,37 @@ TEST(RegionTest, IsEmpty) {
   EXPECT_FALSE(SkIRect::MakeXYWH(0, 0, 2, 2).isEmpty());
 }
 
+TEST(RegionTest, Clear) {
+  Region r;
+
+  r = gfx::Rect(0, 0, 50, 50);
+  EXPECT_FALSE(r.IsEmpty());
+  r.Clear();
+  EXPECT_TRUE(r.IsEmpty());
+
+  r = gfx::Rect(0, 0, 50, 50);
+  r.Union(gfx::Rect(100, 0, 50, 50));
+  r.Union(gfx::Rect(0, 0, 500, 500));
+  EXPECT_FALSE(r.IsEmpty());
+  r.Clear();
+  EXPECT_TRUE(r.IsEmpty());
+}
+
+TEST(RegionSwap, Swap) {
+  Region r1, r2, r3;
+
+  r1 = gfx::Rect(0, 0, 50, 50);
+  r1.Swap(r2);
+  EXPECT_TRUE(r1.IsEmpty());
+  EXPECT_EQ(r2.ToString(), Region(gfx::Rect(0, 0, 50, 50)).ToString());
+
+  r1 = gfx::Rect(0, 0, 50, 50);
+  r1.Union(gfx::Rect(100, 0, 50, 50));
+  r1.Union(gfx::Rect(0, 0, 500, 500));
+  r3 = r1;
+  r1.Swap(r2);
+  EXPECT_EQ(r1.ToString(), Region(gfx::Rect(0, 0, 50, 50)).ToString());
+  EXPECT_EQ(r2.ToString(), r3.ToString());
+}
+
 }  // namespace