Implement features in NativeViewHostAura for scroll end effect

ui/views/controls/native/native_view_host_aura.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/controls/native/native_view_host_aura.h"
 
 #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"
 
 namespace views {
 
 NativeViewHostAura::NativeViewHostAura(NativeViewHost* host)
     : host_(host),
-      installed_clip_(false) {
+      installed_clip_(false),
+      clipping_window_(NULL) {
+  clipping_window_.SetTransparent(true);

[sky, 2013/09/26 22:10:54]

I suspect the ownership isn't right here. Create a test that creates a widget
with ownership of NATIVE_WIDGET_OWNS_WIDGET (the default), add a NativeView with
an aura::window to the widget, and then close the widget (widget->CloseNow()).

[rharrison, 2013/09/30 20:48:45]

I have moved the ownership out of this class, so I think this has been resolved.

+  clipping_window_.Init(ui::LAYER_NOT_DRAWN);
+  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);
   }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // NativeViewHostAura, NativeViewHostWrapper implementation:
 void NativeViewHostAura::NativeViewWillAttach() {
   host_->native_view()->AddObserver(this);
   host_->native_view()->SetProperty(views::kHostViewKey,
       static_cast<View*>(host_));
 }
 
+void NativeViewHostAura::NativeViewAttached() {
+  AddClippingWindow();

[sky, 2013/09/26 22:10:54]

Replace this and NativeWillAttach with AttachNativeView, and move the call to
ReparentWindow to here and NativeViewHostWin.

[rharrison, 2013/09/30 20:48:45]

Done.

+}
+
 void NativeViewHostAura::NativeViewDetaching(bool destroyed) {
+  RemoveClippingWindow();
   if (!destroyed) {
     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);
   }
 }
 
 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
     host_->native_view()->Hide();
   host_->Layout();
 }
 
 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.";
+  gfx::Rect input_rect(x, y, w, h);
+
+  if (!installed_clip_) {
+    orig_bounds_ = host_->native_view()->layer()->bounds();
+  }
+
+  installed_clip_ = true;
+
+  gfx::Rect layer_bounds = orig_bounds_;
+
+  clipping_window_.layer()->SetMasksToBounds(true);
+  gfx::Point clipping_orig = layer_bounds.origin();
+
+  clipping_window_.layer()->SetBounds(gfx::Rect(clipping_orig.x() + x,
+                                                clipping_orig.y() + y,
+                                                w, h));
+  layer_bounds.set_origin(gfx::Point(-x, -y));
+  host_->native_view()->layer()->SetBounds(layer_bounds);
 }
 
 bool NativeViewHostAura::HasInstalledClip() {
   return installed_clip_;
 }
 
 void NativeViewHostAura::UninstallClip() {
+  if (installed_clip_ == false)
+    return;
+
+  clipping_window_.layer()->SetMasksToBounds(false);
+  host_->native_view()->layer()->SetBounds(orig_bounds_);
+
   installed_clip_ = 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));
+  if (host_->fast_resize()) {
+    UninstallClip();
+    gfx::Rect input_rect(x, y, w, h);
+    gfx::Rect native_bounds = host_->native_view()->layer()->bounds();
+    gfx::Point new_native_origin = CalculateNewNativeViewOrigin(input_rect,
+                                                                native_bounds);
+    host_->native_view()->SetBounds(gfx::Rect(new_native_origin.x(),
+                                              new_native_origin.y(),
+                                              native_bounds.width(),
+                                              native_bounds.height()));
+
+    gfx::Point clip_origin = CalculateClipOrigin(input_rect, native_bounds);
+    InstallClip(clip_origin.x(), clip_origin.y(), w, h);
+  } else {
+    clipping_window_.SetBounds(gfx::Rect(x, y, w, h));
+    host_->native_view()->SetBounds(gfx::Rect(0, 0, w, h));
+  }
   host_->native_view()->Show();
 }
 
 void NativeViewHostAura::HideWidget() {
   host_->native_view()->Hide();
 }
 
 void NativeViewHostAura::SetFocus() {
   aura::Window* window = host_->native_view();
   aura::client::FocusClient* client = aura::client::GetFocusClient(window);
   if (client)
     client->FocusWindow(window);
 }
 
 gfx::NativeViewAccessible NativeViewHostAura::GetNativeViewAccessible() {
   return NULL;
 }
 
 void NativeViewHostAura::OnWindowDestroyed(aura::Window* window) {
   DCHECK(window == host_->native_view());
   host_->NativeViewDestroyed();
 }
 
 // static
 NativeViewHostWrapper* NativeViewHostWrapper::CreateWrapper(
     NativeViewHost* host) {
   return new NativeViewHostAura(host);
 }
 
+gfx::Point NativeViewHostAura::CalculateNewNativeViewOrigin(
+    const gfx::Rect& input_rect,
+    const gfx::Rect& native_rect) const {
+  int new_x = input_rect.origin().x() +
+      gfx::ToRoundedInt(host_->GetWidthScaleFactor() * (input_rect.width() -
+                                                        native_rect.width()));
+  int new_y = input_rect.origin().y() +
+      gfx::ToRoundedInt(host_->GetHeightScaleFactor() * (input_rect.height() -
+                                                         native_rect.height()));
+  return gfx::Point(new_x, new_y);
+}
+
+gfx::Point NativeViewHostAura::CalculateClipOrigin(
+    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() {
+  aura::Window* widget_window = host_->GetWidget()->GetNativeView();
+  widget_window->AddChild(&clipping_window_);
+  clipping_window_.AddChild(host_->native_view());
+
+  gfx::Rect bounds = host_->native_view()->bounds();
+  bounds.set_origin(gfx::Point(0,0));
+  host_->native_view()->SetBounds(bounds);
+
+  clipping_window_.Show();
+  host_->Layout();
+}
+
+void NativeViewHostAura::RemoveClippingWindow() {
+  if (host_->native_view()->parent() == &clipping_window_) {
+    clipping_window_.parent()->AddChild(host_->native_view());
+    clipping_window_.parent()->RemoveChild(&clipping_window_);
+    host_->native_view()->SetBounds(clipping_window_.bounds());
+    clipping_window_.Hide();
+  }
+}
+
 }  // namespace views