Mus Demo: Code cleanup in MusDemo::WindowTreeData

services/ui/demo/mus_demo.cc

Index: services/ui/demo/mus_demo.cc
diff --git a/services/ui/demo/mus_demo.cc b/services/ui/demo/mus_demo.cc
index 6295e83b5dfad815ac6f014c163efd196e5de7fa..c0cde5a9b49f6d20d53437428fd4ece4e2408652 100644
--- a/services/ui/demo/mus_demo.cc
+++ b/services/ui/demo/mus_demo.cc
@@ -73,7 +73,6 @@ class MusDemo::WindowTreeData {
       std::unique_ptr<aura::WindowTreeHostMus> window_tree_host) {
     Init(std::move(window_tree_host));
   }
-  ~WindowTreeData();
 
  private:
   // Initializes the window tree host and start drawing frames.
@@ -82,15 +81,14 @@ class MusDemo::WindowTreeData {
   // Draws one frame, incrementing the rotation angle.
   void DrawFrame();
 
+  // Helper function to retrieve the window to which we draw the bitmap.
+  aura::Window* BitmapWindow() {

[sky, 2017/02/10 18:48:37]

GetBitmapWindow(), or as this is inlined and cheap, bitmap_window().

[fwang, 2017/02/11 09:58:48]

Done.

+    return window_tree_host_->window()->children()[0];

[sky, 2017/02/10 18:48:38]

DCHECK(!children.empty())

[fwang, 2017/02/11 09:58:48]

Done.

+  }
+
   // The Window tree host corresponding to this data.
   std::unique_ptr<aura::WindowTreeHostMus> window_tree_host_;
 
-  // Root window of the window tree host.
-  aura::Window* root_window_ = nullptr;
-
-  // Window to which we draw the bitmap.
-  std::unique_ptr<aura::Window> bitmap_window_;
-
   // Destroys itself when the window gets destroyed.
   aura_extra::ImageWindowDelegate* window_delegate_ = nullptr;
 
@@ -99,34 +97,24 @@ class MusDemo::WindowTreeData {
 
   // Current rotation angle for drawing.
   double angle_ = 0.0;
-
-  // Last time a frame was drawn.
-  base::TimeTicks last_draw_frame_time_;
 };

[sky, 2017/02/10 18:48:38]

DISALLOW...

[fwang, 2017/02/11 09:58:48]

Done.

 
-MusDemo::WindowTreeData::~WindowTreeData() {
-  timer_.Stop();
-  root_window_->RemoveChild(bitmap_window_.get());
-  bitmap_window_.reset();
-}
-
 void MusDemo::WindowTreeData::Init(
     std::unique_ptr<aura::WindowTreeHostMus> window_tree_host) {
   window_tree_host->InitHost();
   window_tree_host->Show();
-  root_window_ = window_tree_host->window();
   // Take ownership of the WTH.
   window_tree_host_ = std::move(window_tree_host);
 
   // Initialize the window for the bitmap.
   window_delegate_ = new aura_extra::ImageWindowDelegate();
-  bitmap_window_ = base::MakeUnique<aura::Window>(window_delegate_);
-  bitmap_window_->Init(LAYER_TEXTURED);
-  bitmap_window_->SetBounds(root_window_->bounds());
-  bitmap_window_->Show();
-  bitmap_window_->SetName("Bitmap");
-
-  root_window_->AddChild(bitmap_window_.get());
+  aura::Window* root_window = window_tree_host_->window();
+  aura::Window* bitmap_window = new aura::Window(window_delegate_);
+  bitmap_window->Init(LAYER_TEXTURED);
+  bitmap_window->SetBounds(root_window->bounds());

[sky, 2017/02/10 18:48:38]

bitmap_window should have the same size, but an origin of 0x0, e.g.
gfx::Rect(root_window->bounds().size());

[fwang, 2017/02/11 09:58:48]

Done.

+  bitmap_window->Show();
+  bitmap_window->SetName("Bitmap");
+  root_window->AddChild(bitmap_window);
 
   // Draw initial frame and start the timer to regularly draw frames.
   DrawFrame();
@@ -257,17 +245,11 @@ bool MusDemo::IsWindowActive(aura::Window* window) { return false; }
 void MusDemo::OnWmDeactivateWindow(aura::Window* window) {}
 
 void MusDemo::WindowTreeData::DrawFrame() {
-  base::TimeTicks now = base::TimeTicks::Now();
-
-  VLOG(1) << (now - last_draw_frame_time_).InMilliseconds()
-          << "ms since the last frame was drawn.";
-  last_draw_frame_time_ = now;
-
   angle_ += 2.0;
   if (angle_ >= 360.0)
     angle_ = 0.0;
 
-  const gfx::Rect& bounds = bitmap_window_->bounds();
+  const gfx::Rect& bounds = BitmapWindow()->bounds();
 
   // Allocate a bitmap of correct size.
   SkBitmap bitmap;
@@ -287,7 +269,7 @@ void MusDemo::WindowTreeData::DrawFrame() {
   gfx::Image image(image_skia);
 
   window_delegate_->SetImage(image);
-  bitmap_window_->SchedulePaintInRect(bitmap_window_->bounds());
+  BitmapWindow()->SchedulePaintInRect(BitmapWindow()->bounds());

[sky, 2017/02/10 18:48:37]

SchedulePaintInRect() takes a rectangle in the coordinates of the view you are
calling paint on. You are passing the bounds of the same window. Bounds are in
the coordinates of the parent. In other words you have a coordinate system
mismatch here. It doesn't really matter in this case since you know the origin
is 0x0, but it's good practice to do the right thing in case that changes, which
is window->SchedulePaintInRect(gfx::Rect(window->bounds().size());

[fwang, 2017/02/11 09:58:48]

Done.

 }
 
 }  // namespace demo