Implement NativeViewHostAura::InstallClip.

ui/views/controls/native/native_view_host_aura.cc

Index: ui/views/controls/native/native_view_host_aura.cc
diff --git a/ui/views/controls/native/native_view_host_aura.cc b/ui/views/controls/native/native_view_host_aura.cc
index 49bf733bbe2ae06567f1b9d148db2255b743ab85..0a3346334a1f91a187f7557bbd8fa00cccda90ea 100644
--- a/ui/views/controls/native/native_view_host_aura.cc
+++ b/ui/views/controls/native/native_view_host_aura.cc
@@ -16,41 +16,48 @@ namespace views {
 
 NativeViewHostAura::NativeViewHostAura(NativeViewHost* host)
     : host_(host),
-      installed_clip_(false) {
+      installed_clip_(false),
+      clipping_window_(NULL) {
+  clipping_window_.Init(aura::WINDOW_LAYER_NOT_DRAWN);
+  clipping_window_.set_owned_by_parent(false);
+  clipping_window_.layer()->set_name("NativeViewHostAuraClip");
+  clipping_window_.layer()->SetMasksToBounds(true);
 }
 
 NativeViewHostAura::~NativeViewHostAura() {
   if (host_->native_view()) {
     host_->native_view()->ClearProperty(views::kHostViewKey);
     host_->native_view()->RemoveObserver(this);
+    if (host_->native_view()->parent() == &clipping_window_)
+      clipping_window_.RemoveChild(host_->native_view());
   }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // NativeViewHostAura, NativeViewHostWrapper implementation:
-void NativeViewHostAura::NativeViewWillAttach() {
+void NativeViewHostAura::AttachNativeView() {
   host_->native_view()->AddObserver(this);
   host_->native_view()->SetProperty(views::kHostViewKey,
       static_cast<View*>(host_));
+  AddClippingWindow();
 }
 
 void NativeViewHostAura::NativeViewDetaching(bool destroyed) {
   if (!destroyed) {
-    host_->native_view()->ClearProperty(views::kHostViewKey);
     host_->native_view()->RemoveObserver(this);
+    host_->native_view()->ClearProperty(views::kHostViewKey);
     host_->native_view()->Hide();
     if (host_->native_view()->parent())
       Widget::ReparentNativeView(host_->native_view(), NULL);
   }
+  RemoveClippingWindow();
 }
 
 void NativeViewHostAura::AddedToWidget() {
   if (!host_->native_view())
     return;
 
-  aura::Window* widget_window = host_->GetWidget()->GetNativeView();
-  if (host_->native_view()->parent() != widget_window)
-    widget_window->AddChild(host_->native_view());
+  AddClippingWindow();
   if (host_->IsDrawn())
     host_->native_view()->Show();
   else
@@ -63,13 +70,13 @@ void NativeViewHostAura::RemovedFromWidget() {
     host_->native_view()->Hide();
     if (host_->native_view()->parent())
       host_->native_view()->parent()->RemoveChild(host_->native_view());
+    RemoveClippingWindow();
   }
 }
 
 void NativeViewHostAura::InstallClip(int x, int y, int w, int h) {
-  // Note that this does not pose a problem functionality wise - it might
-  // however pose a speed degradation if not implemented.
-  LOG(WARNING) << "NativeViewHostAura::InstallClip is not implemented yet.";
+  installed_clip_ = true;

[sky, 2014/06/10 16:11:06]

Is it possible to nuke installed_clip_ and use clip_rect_? If necessary, make
clip_rect_ a scoped_ptr.

[calamity, 2014/06/11 09:50:26]

Done.

+  clip_rect_ = host_->ConvertRectToWidget(gfx::Rect(x, y, w, h));
 }
 
 bool NativeViewHostAura::HasInstalledClip() {
@@ -81,8 +88,15 @@ void NativeViewHostAura::UninstallClip() {
 }
 
 void NativeViewHostAura::ShowWidget(int x, int y, int w, int h) {
-  // TODO: need to support fast resize.
-  host_->native_view()->SetBounds(gfx::Rect(x, y, w, h));
+  if (host_->fast_resize())
+    InstallClip(x, y, w, h);

[sky, 2014/06/10 16:11:06]

Doesn't InstallClip expect coordinates in the views coordinate space but x/y/w/h
is in the coordinates of the widget?

[calamity, 2014/06/11 09:50:26]

Hmm. Yeah. I think that this is actually completely wrong at the moment since it
uses w and h below which I believe is against the whole point of fast resize.
I'll just leave this as a TODO as this patch is getting a bit too unwieldy.

+
+  clipping_window_.SetBounds(installed_clip_ ? clip_rect_
+                                             : gfx::Rect(x, y, w, h));
+
+  gfx::Point clip_offset = clipping_window_.bounds().origin();
+  host_->native_view()->SetBounds(
+      gfx::Rect(x - clip_offset.x(), y - clip_offset.y(), w, h));
   host_->native_view()->Show();
 }
 
@@ -118,4 +132,35 @@ NativeViewHostWrapper* NativeViewHostWrapper::CreateWrapper(
   return new NativeViewHostAura(host);
 }
 
+void NativeViewHostAura::AddClippingWindow() {
+  RemoveClippingWindow();
+  clipping_window_.AddChild(host_->native_view());
+
+  gfx::Rect bounds = host_->native_view()->bounds();
+  if (host_->GetWidget()->GetNativeView()) {
+    Widget::ReparentNativeView(&clipping_window_,
+                               host_->GetWidget()->GetNativeView());
+  }
+
+  clipping_window_.SetBounds(bounds);
+  bounds.set_origin(gfx::Point(0, 0));
+  host_->native_view()->SetBounds(bounds);
+  clipping_window_.Show();
+}
+
+void NativeViewHostAura::RemoveClippingWindow() {
+  if (host_->native_view()->parent() == &clipping_window_) {
+    if (host_->GetWidget()->GetNativeView()) {
+      Widget::ReparentNativeView(host_->native_view(),
+                                 host_->GetWidget()->GetNativeView());
+    } else {
+      clipping_window_.RemoveChild(host_->native_view());
+    }
+    host_->native_view()->SetBounds(clipping_window_.bounds());
+  }
+  clipping_window_.Hide();
+  if (clipping_window_.parent())
+    clipping_window_.parent()->RemoveChild(&clipping_window_);
+}
+
 }  // namespace views