Notification for device scale factor change

BUG=105165
TEST=updated compositor test to cover OnDeviceScaleFactorChagned.

Review URL: https://chromiumcodereview.appspot.com/10391165

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@137571 0039d316-1c4b-4281-b951-d872f2087c98

13 files changed, 70 insertions, 2 deletions

diff --git a/ui/aura/demo/demo_main.cc b/ui/aura/demo/demo_main.cc
index 98b6f84..fb8e683 100644
--- a/ui/aura/demo/demo_main.cc
+++ b/ui/aura/demo/demo_main.cc
@@ -64,6 +64,7 @@ class DemoWindowDelegate : public aura::WindowDelegate {
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE {
     canvas->DrawColor(color_, SkXfermode::kSrc_Mode);
   }
+  virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE {}
   virtual void OnWindowDestroying() OVERRIDE {}
   virtual void OnWindowDestroyed() OVERRIDE {}
   virtual void OnWindowVisibilityChanged(bool visible) OVERRIDE {}
diff --git a/ui/aura/test/test_window_delegate.cc b/ui/aura/test/test_window_delegate.cc
index 0865079..52b50d7 100644
--- a/ui/aura/test/test_window_delegate.cc
+++ b/ui/aura/test/test_window_delegate.cc
@@ -69,6 +69,10 @@ void TestWindowDelegate::OnCaptureLost() {
 void TestWindowDelegate::OnPaint(gfx::Canvas* canvas) {
 }
 
+void TestWindowDelegate::OnDeviceScaleFactorChanged(
+    float device_scale_factor) {
+}
+
 void TestWindowDelegate::OnWindowDestroying() {
 }
 
diff --git a/ui/aura/test/test_window_delegate.h b/ui/aura/test/test_window_delegate.h
index 57a5ba1..294709d 100644
--- a/ui/aura/test/test_window_delegate.h
+++ b/ui/aura/test/test_window_delegate.h
@@ -38,6 +38,7 @@ class TestWindowDelegate : public WindowDelegate {
   virtual bool CanFocus() OVERRIDE;
   virtual void OnCaptureLost() OVERRIDE;
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
+  virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE;
   virtual void OnWindowDestroying() OVERRIDE;
   virtual void OnWindowDestroyed() OVERRIDE;
   virtual void OnWindowVisibilityChanged(bool visible) OVERRIDE;
diff --git a/ui/aura/window.cc b/ui/aura/window.cc
index d18937b..4128d90 100644
--- a/ui/aura/window.cc
+++ b/ui/aura/window.cc
@@ -794,6 +794,11 @@ void Window::OnPaintLayer(gfx::Canvas* canvas) {
     delegate_->OnPaint(canvas);
 }
 
+void Window::OnDeviceScaleFactorChanged(float device_scale_factor) {
+  if (delegate_)
+    delegate_->OnDeviceScaleFactorChanged(device_scale_factor);
+}
+
 void Window::UpdateLayerName(const std::string& name) {
 #if !defined(NDEBUG)
   DCHECK(layer());
diff --git a/ui/aura/window.h b/ui/aura/window.h
index 7917fba..382d582 100644
--- a/ui/aura/window.h
+++ b/ui/aura/window.h
@@ -395,6 +395,7 @@ class AURA_EXPORT Window : public ui::LayerDelegate,
 
   // Overridden from ui::LayerDelegate:
   virtual void OnPaintLayer(gfx::Canvas* canvas) OVERRIDE;
+  virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE;
 
   // Updates the layer name with a name based on the window's name and id.
   void UpdateLayerName(const std::string& name);
diff --git a/ui/aura/window_delegate.h b/ui/aura/window_delegate.h
index c3b79e2..34521c8 100644
--- a/ui/aura/window_delegate.h
+++ b/ui/aura/window_delegate.h
@@ -64,6 +64,9 @@ class AURA_EXPORT WindowDelegate {
   // Asks the delegate to paint window contents into the supplied canvas.
   virtual void OnPaint(gfx::Canvas* canvas) = 0;
 
+  // Called when the window's device scale factor has changed.
+  virtual void OnDeviceScaleFactorChanged(float device_scale_factor) = 0;
+
   // Called from Window's destructor before OnWindowDestroyed and before the
   // children have been destroyed and the window has been removed from its
   // parent.
diff --git a/ui/compositor/layer.cc b/ui/compositor/layer.cc
index ae2085f..620ec58 100644
--- a/ui/compositor/layer.cc
+++ b/ui/compositor/layer.cc
@@ -377,6 +377,8 @@ void Layer::OnDeviceScaleFactorChanged(float device_scale_factor) {
   RecomputeTransform();
   RecomputeDrawsContentAndUVRect();
   SchedulePaint(gfx::Rect(bounds_.size()));
+  if (delegate_)
+    delegate_->OnDeviceScaleFactorChanged(device_scale_factor);
   for (size_t i = 0; i < children_.size(); ++i)
     children_[i]->OnDeviceScaleFactorChanged(device_scale_factor);
 }
diff --git a/ui/compositor/layer_delegate.h b/ui/compositor/layer_delegate.h
index 292e399..cb00366 100644
--- a/ui/compositor/layer_delegate.h
+++ b/ui/compositor/layer_delegate.h
@@ -21,6 +21,9 @@ class COMPOSITOR_EXPORT LayerDelegate {
   // clipped to the Layer's invalid rect.
   virtual void OnPaintLayer(gfx::Canvas* canvas) = 0;
 
+  // Called when the layer's device scale factor has changed.
+  virtual void OnDeviceScaleFactorChanged(float device_scale_factor) = 0;
+
  protected:
   virtual ~LayerDelegate() {}
 };
diff --git a/ui/compositor/layer_unittest.cc b/ui/compositor/layer_unittest.cc
index 3af502d..581e1db 100644
--- a/ui/compositor/layer_unittest.cc
+++ b/ui/compositor/layer_unittest.cc
@@ -132,6 +132,9 @@ class ColoredLayer : public Layer, public LayerDelegate {
     canvas->DrawColor(color_);
   }
 
+  virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE {
+  }
+
  private:
   SkColor color_;
 };
@@ -212,7 +215,7 @@ class LayerWithRealCompositorTest : public testing::Test {
 // LayerDelegate that paints colors to the layer.
 class TestLayerDelegate : public LayerDelegate {
  public:
-  explicit TestLayerDelegate() : color_index_(0) {}
+  explicit TestLayerDelegate() { reset(); }
   virtual ~TestLayerDelegate() {}
 
   void AddColor(SkColor color) {
@@ -226,6 +229,10 @@ class TestLayerDelegate : public LayerDelegate {
     return StringPrintf("%.1f %.1f", scale_x_, scale_y_);
   }
 
+  float device_scale_factor() const {
+    return device_scale_factor_;
+  }
+
   // Overridden from LayerDelegate:
   virtual void OnPaintLayer(gfx::Canvas* canvas) OVERRIDE {
     SkBitmap contents = canvas->ExtractBitmap();
@@ -237,10 +244,15 @@ class TestLayerDelegate : public LayerDelegate {
     scale_y_ = matrix.getScaleY();
   }
 
+  virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE {
+    device_scale_factor_ = device_scale_factor;
+  }
+
   void reset() {
     color_index_ = 0;
     paint_size_.SetSize(0, 0);
     scale_x_ = scale_y_ = 0.0f;
+    device_scale_factor_ = 0.0f;
   }
 
  private:
@@ -249,6 +261,7 @@ class TestLayerDelegate : public LayerDelegate {
   gfx::Size paint_size_;
   float scale_x_;
   float scale_y_;
+  float device_scale_factor_;
 
   DISALLOW_COPY_AND_ASSIGN(TestLayerDelegate);
 };
@@ -270,6 +283,8 @@ class DrawTreeLayerDelegate : public LayerDelegate {
   virtual void OnPaintLayer(gfx::Canvas* canvas) OVERRIDE {
     painted_ = true;
   }
+  virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE {
+  }
 
   bool painted_;
 
@@ -286,6 +301,8 @@ class NullLayerDelegate : public LayerDelegate {
   // Overridden from LayerDelegate:
   virtual void OnPaintLayer(gfx::Canvas* canvas) OVERRIDE {
   }
+  virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE {
+  }
 
   DISALLOW_COPY_AND_ASSIGN(NullLayerDelegate);
 };
@@ -1000,6 +1017,9 @@ class SchedulePaintLayerDelegate : public LayerDelegate {
       last_clip_rect_ = gfx::SkRectToRect(sk_clip_rect);
   }
 
+  virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE {
+  }
+
   int paint_count_;
   Layer* layer_;
   gfx::Rect schedule_paint_rect_;
@@ -1071,6 +1091,9 @@ TEST_F(LayerWithRealCompositorTest, MAYBE_ScaleUpDown) {
   EXPECT_EQ("200x220", size_in_pixel.ToString());
   size_in_pixel = l1->web_layer().bounds();
   EXPECT_EQ("140x180", size_in_pixel.ToString());
+  // No scale change, so no scale notification.
+  EXPECT_EQ(0.0f, root_delegate.device_scale_factor());
+  EXPECT_EQ(0.0f, l1_delegate.device_scale_factor());
 
   RunPendingMessages();
   EXPECT_EQ("200x220", root_delegate.paint_size().ToString());
@@ -1085,6 +1108,9 @@ TEST_F(LayerWithRealCompositorTest, MAYBE_ScaleUpDown) {
   EXPECT_EQ("400x440", size_in_pixel.ToString());
   size_in_pixel = l1->web_layer().bounds();
   EXPECT_EQ("280x360", size_in_pixel.ToString());
+  // New scale factor must have been notified.
+  EXPECT_EQ(2.0f, root_delegate.device_scale_factor());
+  EXPECT_EQ(2.0f, l1_delegate.device_scale_factor());
 
   // Canvas size must have been scaled down up.
   RunPendingMessages();
@@ -1102,6 +1128,9 @@ TEST_F(LayerWithRealCompositorTest, MAYBE_ScaleUpDown) {
   EXPECT_EQ("200x220", size_in_pixel.ToString());
   size_in_pixel = l1->web_layer().bounds();
   EXPECT_EQ("140x180", size_in_pixel.ToString());
+  // New scale factor must have been notified.
+  EXPECT_EQ(1.0f, root_delegate.device_scale_factor());
+  EXPECT_EQ(1.0f, l1_delegate.device_scale_factor());
 
   // Canvas size must have been scaled down too.
   RunPendingMessages();
@@ -1112,8 +1141,12 @@ TEST_F(LayerWithRealCompositorTest, MAYBE_ScaleUpDown) {
 
   root_delegate.reset();
   l1_delegate.reset();
-  // Just changing the size shouldn't trigger repaint.
+  // Just changing the size shouldn't notify the scale change nor
+  // trigger repaint.
   GetCompositor()->SetScaleAndSize(1.0f, gfx::Size(1000, 1000));
+  // No scale change, so no scale notification.
+  EXPECT_EQ(0.0f, root_delegate.device_scale_factor());
+  EXPECT_EQ(0.0f, l1_delegate.device_scale_factor());
   RunPendingMessages();
   EXPECT_EQ("0x0", root_delegate.paint_size().ToString());
   EXPECT_EQ("0.0 0.0", root_delegate.ToScaleString());
@@ -1139,6 +1172,7 @@ TEST_F(LayerWithRealCompositorTest, MAYBE_ScaleReparent) {
   EXPECT_EQ("10,20 140x180", l1->bounds().ToString());
   gfx::Size size_in_pixel = l1->web_layer().bounds();
   EXPECT_EQ("140x180", size_in_pixel.ToString());
+  EXPECT_EQ(0.0f, l1_delegate.device_scale_factor());
 
   RunPendingMessages();
   EXPECT_EQ("140x180", l1_delegate.paint_size().ToString());
@@ -1159,6 +1193,7 @@ TEST_F(LayerWithRealCompositorTest, MAYBE_ScaleReparent) {
   EXPECT_EQ("10,20 140x180", l1->bounds().ToString());
   size_in_pixel = l1->web_layer().bounds();
   EXPECT_EQ("280x360", size_in_pixel.ToString());
+  EXPECT_EQ(2.0f, l1_delegate.device_scale_factor());
   RunPendingMessages();
   EXPECT_EQ("280x360", l1_delegate.paint_size().ToString());
   EXPECT_EQ("2.0 2.0", l1_delegate.ToScaleString());
@@ -1179,6 +1214,9 @@ TEST_F(LayerWithRealCompositorTest, MAYBE_NoScaleCanvas) {
 
   GetCompositor()->SetScaleAndSize(2.0f, gfx::Size(500, 500));
   GetCompositor()->SetRootLayer(root.get());
+  // Scale factor change is notified regardless of scale_canvas flag.
+  EXPECT_EQ(2.0f, l1_delegate.device_scale_factor());
+
   RunPendingMessages();
   EXPECT_EQ("280x360", l1_delegate.paint_size().ToString());
   EXPECT_EQ("1.0 1.0", l1_delegate.ToScaleString());
diff --git a/ui/views/view.cc b/ui/views/view.cc
index f5dd39b..cbcb45c 100644
--- a/ui/views/view.cc
+++ b/ui/views/view.cc
@@ -1230,6 +1230,10 @@ void View::OnPaintLayer(gfx::Canvas* canvas) {
   PaintCommon(canvas);
 }
 
+void View::OnDeviceScaleFactorChanged(float device_scale_factor) {
+  // Repainting with new scale factor will paint the content at the right scale.
+}
+
 void View::ReorderLayers() {
   View* v = this;
   while (v && !v->layer())
diff --git a/ui/views/view.h b/ui/views/view.h
index fc4a27f..8492d95 100644
--- a/ui/views/view.h
+++ b/ui/views/view.h
@@ -996,6 +996,7 @@ class VIEWS_EXPORT View : public ui::LayerDelegate,
 
   // Overridden from ui::LayerDelegate:
   virtual void OnPaintLayer(gfx::Canvas* canvas) OVERRIDE;
+  virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE;
 
   // Finds the layer that this view paints to (it may belong to an ancestor
   // view), then reorders the immediate children of that layer to match the
diff --git a/ui/views/widget/native_widget_aura.cc b/ui/views/widget/native_widget_aura.cc
index b63e8fd..a71b3d7 100644
--- a/ui/views/widget/native_widget_aura.cc
+++ b/ui/views/widget/native_widget_aura.cc
@@ -784,6 +784,10 @@ void NativeWidgetAura::OnPaint(gfx::Canvas* canvas) {
   delegate_->OnNativeWidgetPaint(canvas);
 }
 
+void NativeWidgetAura::OnDeviceScaleFactorChanged(float device_scale_factor) {
+  // Repainting with new scale factor will paint the content at the right scale.
+}
+
 void NativeWidgetAura::OnWindowDestroying() {
   delegate_->OnNativeWidgetDestroying();
 
diff --git a/ui/views/widget/native_widget_aura.h b/ui/views/widget/native_widget_aura.h
index c9a1480..7d89a77 100644
--- a/ui/views/widget/native_widget_aura.h
+++ b/ui/views/widget/native_widget_aura.h
@@ -144,6 +144,7 @@ class VIEWS_EXPORT NativeWidgetAura : public internal::NativeWidgetPrivate,
   virtual bool CanFocus() OVERRIDE;
   virtual void OnCaptureLost() OVERRIDE;
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
+  virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE;
   virtual void OnWindowDestroying() OVERRIDE;
   virtual void OnWindowDestroyed() OVERRIDE;
   virtual void OnWindowVisibilityChanged(bool visible) OVERRIDE;