Implement features in NativeViewHostAura for scroll end effect

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 444f5803e687830df18efb39ca68f2bf5f51a3b0..d2d244f77f3ca27e4e2bbd832e484230ad47b551 100644
--- a/ui/views/controls/native/native_view_host_aura.cc
+++ b/ui/views/controls/native/native_view_host_aura.cc
@@ -7,6 +7,7 @@
 #include "base/logging.h"
 #include "ui/aura/focus_manager.h"
 #include "ui/aura/window.h"
+#include "ui/gfx/safe_integer_conversions.h"
 #include "ui/views/controls/native/native_view_host.h"
 #include "ui/views/view_constants_aura.h"
 #include "ui/views/widget/widget.h"
@@ -15,25 +16,34 @@ namespace views {
 
 NativeViewHostAura::NativeViewHostAura(NativeViewHost* host)
     : host_(host),
-      installed_clip_(false) {
+      installed_clip_(false),
+      clipping_window_(NULL) {
+    clipping_window_.SetTransparent(true);
+    clipping_window_.Init(ui::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();
   }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // 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) {
+  RemoveClippingWindow();
   if (!destroyed) {
     host_->native_view()->ClearProperty(views::kHostViewKey);
     host_->native_view()->RemoveObserver(this);
@@ -47,9 +57,9 @@ 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());
+  if (host_->native_view()->parent() !=  host_->GetWidget()->GetNativeView())
+    AddClippingWindow();
+
   if (host_->IsDrawn())
     host_->native_view()->Show();
   else
@@ -60,15 +70,20 @@ void NativeViewHostAura::AddedToWidget() {
 void NativeViewHostAura::RemovedFromWidget() {
   if (host_->native_view()) {
     host_->native_view()->Hide();
+    RemoveClippingWindow();
     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;
+  clip_rect_ = gfx::Rect(x + orig_bounds_.origin().x(),
+                         y + orig_bounds_.origin().y(),
+                         w,
+                         h);
+  UpdateClippingWindow();
+  clipping_window_.layer()->SetMasksToBounds(true);
 }
 
 bool NativeViewHostAura::HasInstalledClip() {
@@ -76,12 +91,25 @@ bool NativeViewHostAura::HasInstalledClip() {
 }
 
 void NativeViewHostAura::UninstallClip() {
+  if (installed_clip_ == false)
+    return;
   installed_clip_ = false;
+  UpdateClippingWindow();
+  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));
+  UninstallClip();

[xiyuan, 2013/10/09 18:31:47]

This should go inside host_->fast_resize() because in non-fast-resize path,
ShowWidget is called after InstallClip and this would incorrectly clear the
clip.

[rharrison, 2013/10/10 15:08:55]

Done.

+  if (host_->fast_resize()) {
+    gfx::Rect input_bounds(x, y, w, h);

[xiyuan, 2013/10/09 18:31:47]

Where is this used?

[rharrison, 2013/10/10 15:08:55]

Was part of some debug logging I had, thanks for catching this.

+    InstallClip(x - clipping_window_.bounds().origin().x(),

[xiyuan, 2013/10/09 18:31:47]

Should we use orig_bounds_ to convert |x|, |y| into host_'s local coordinates?

[rharrison, 2013/10/10 15:08:55]

Done.

+                y - clipping_window_.bounds().origin().y(),
+                w,
+                h);
+  } else {
+    orig_bounds_ = gfx::Rect(x, y, w, h);
+    UpdateClippingWindow();
+  }
   host_->native_view()->Show();
 }
 
@@ -111,4 +139,65 @@ NativeViewHostWrapper* NativeViewHostWrapper::CreateWrapper(
   return new NativeViewHostAura(host);
 }
 
+gfx::Point NativeViewHostAura::CalculateNativeViewOrigin(
+    const gfx::Rect& input_rect,
+    const gfx::Rect& native_rect) const {
+  int new_x = gfx::ToRoundedInt(host_->GetWidthScaleFactor() *
+                                (input_rect.width() -
+                                 native_rect.width()));
+  int new_y = gfx::ToRoundedInt(host_->GetHeightScaleFactor() *
+                                (input_rect.height() -
+                                 native_rect.height()));
+  return gfx::Point(new_x, new_y);
+}
+
+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));
+  orig_bounds_ = bounds;

[xiyuan, 2013/10/09 18:31:47]

Which coordinates is |orig_bounds_| using? This looks not right.

[rharrison, 2013/10/10 15:08:55]

orig_bounds_ is in the coordinate space of host_->GetWidget(), which is going to
become the parent ... oh I see the problem now... yeah that is wrong, it should
be with the original origin, not (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());
+    }
+
+    clipping_window_.Hide();
+    host_->native_view()->SetBounds(clipping_window_.bounds());
+    if (clipping_window_.parent())
+      clipping_window_.parent()->RemoveChild(&clipping_window_);
+  }
+}
+
+void NativeViewHostAura::UpdateClippingWindow() {
+  if (installed_clip_) {
+    clipping_window_.SetBounds(clip_rect_);
+    gfx::Rect native_view_bounds = host_->native_view()->bounds();
+    gfx::Point native_view_origin =
+        CalculateNativeViewOrigin(clipping_window_.bounds(),
+                                  native_view_bounds);
+
+    native_view_bounds.set_origin(native_view_origin);
+    host_->native_view()->SetBounds(native_view_bounds);
+  } else {
+    clip_rect_ = orig_bounds_;
+    clipping_window_.SetBounds(orig_bounds_);
+    host_->native_view()->SetBounds(gfx::Rect(orig_bounds_.size()));
+  }
+}
+
 }  // namespace views