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..04af837354d943db8e9e8775c581b59091d6e7e4 100644
--- a/ui/views/controls/native/native_view_host_aura.cc
+++ b/ui/views/controls/native/native_view_host_aura.cc
@@ -15,32 +15,42 @@
 namespace views {
 
 NativeViewHostAura::NativeViewHostAura(NativeViewHost* host)
-    : host_(host),
-      installed_clip_(false) {
+    : host_(host), installed_clip_(false), clipping_window_(NULL) {

[sky, 2014/06/05 15:49:01]

nit: one param per line.

[calamity, 2014/06/06 08:13:44]

Done.

+  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(false);
 }
 
 NativeViewHostAura::~NativeViewHostAura() {
   if (host_->native_view()) {
     host_->native_view()->ClearProperty(views::kHostViewKey);
     host_->native_view()->RemoveObserver(this);
+    RemoveClippingWindow();

[sky, 2014/06/05 15:49:01]

Are you sure this is necessary here? In particular I'm questioning whether you
need to reparent the nativeview.

[calamity, 2014/06/06 08:13:44]

Removing this crashes NativeViewHostAuraTest.HostViewPropertyKey...

[sky, 2014/06/06 15:53:57]

What does the trace look like?

[calamity, 2014/06/10 08:48:46]

Evidently we need to remove the native view from the clipping window at least or
else destroying the clipping window destroys the native view. Removed this line
in patchset #3 and replaced it with code that doesn't cause a reparent.

   }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // 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) {
+    RemoveClippingWindow();
     host_->native_view()->ClearProperty(views::kHostViewKey);
     host_->native_view()->RemoveObserver(this);
     host_->native_view()->Hide();
     if (host_->native_view()->parent())
       Widget::ReparentNativeView(host_->native_view(), NULL);
+  } else {
+    clipping_window_.Hide();

[sky, 2014/06/05 15:49:01]

Why is this in an else? Shouldn't you always do it?

[calamity, 2014/06/06 08:13:44]

RemoveClippingView actually takes care of this. Fixed.

+    if (clipping_window_.parent())
+      clipping_window_.parent()->RemoveChild(&clipping_window_);
   }
 }
 
@@ -48,9 +58,7 @@ 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
@@ -61,15 +69,16 @@ void NativeViewHostAura::AddedToWidget() {
 void NativeViewHostAura::RemovedFromWidget() {
   if (host_->native_view()) {
     host_->native_view()->Hide();
+    RemoveClippingWindow();

[sky, 2014/06/05 15:49:01]

Seems weird to reparent the native_view to the widget and then remove it in the
next line.

[calamity, 2014/06/06 08:13:44]

Switched the order. RemoveClippingWindow() won't reparent after the native view
is removed from its parent.

     if (host_->native_view()->parent())
       host_->native_view()->parent()->RemoveChild(host_->native_view());
   }
 }
 
 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;
+  clipping_window_.SetBounds(host_->ConvertRectToWidget(gfx::Rect(x, y, w, h)));
+  clipping_window_.layer()->SetMasksToBounds(true);

[sky, 2014/06/05 15:49:01]

Can't you always set mask to bounds true?

[calamity, 2014/06/06 08:13:44]

It's set to false so that the native view can draw anywhere within the widget
when a clip isn't installed.

[sky, 2014/06/06 15:53:57]

Isn't the only time the size of the clipping_window and native_view differ when
InstallClip is invoked? That's why I think you can always set this mask to
bounds to true.

[calamity, 2014/06/10 08:48:46]

Oops, this comment was outdated. Yeah. Since I set the bounds correctly in patch
#2, this is now always SetMasksToBounds(true).

 }
 
 bool NativeViewHostAura::HasInstalledClip() {
@@ -77,13 +86,22 @@ bool NativeViewHostAura::HasInstalledClip() {
 }
 
 void NativeViewHostAura::UninstallClip() {
+  if (installed_clip_ == false)
+    return;
+
   installed_clip_ = false;
+  clipping_window_.layer()->SetMasksToBounds(false);
 }
 
 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));
-  host_->native_view()->Show();
+  if (host_->fast_resize()) {
+    InstallClip(x, y, w, h);
+  } else {
+    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();
+  }
 }
 
 void NativeViewHostAura::HideWidget() {
@@ -118,4 +136,34 @@ NativeViewHostWrapper* NativeViewHostWrapper::CreateWrapper(
   return new NativeViewHostAura(host);
 }
 
+void NativeViewHostAura::AddClippingWindow() {
+  gfx::Rect bounds = host_->native_view()->bounds();
+
+  if (host_->GetWidget()->GetNativeView()) {
+    Widget::ReparentNativeView(&clipping_window_,
+                               host_->GetWidget()->GetNativeView());
+  }
+  Widget::ReparentNativeView(host_->native_view(), &clipping_window_);
+
+  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