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) {
+  clipping_layer_.reset(new ui::Layer(ui::LAYER_NOT_DRAWN));
+  clipping_layer_->set_name("NativeViewHostAuraClip");
+  clipping_layer_->SetMasksToBounds(true);
+  clipping_layer_->SetFillsBoundsOpaquely(false);
 }
 
 NativeViewHostAura::~NativeViewHostAura() {
   if (host_->native_view()) {
     host_->native_view()->ClearProperty(views::kHostViewKey);
     host_->native_view()->RemoveObserver(this);
   }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ skipping 30 matching lines @@
 
 void NativeViewHostAura::RemovedFromWidget() {
   if (host_->native_view()) {
     host_->native_view()->Hide();
     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_) {
+    host_->native_view()->layer()->parent()->Add(clipping_layer_.get());
+    clipping_layer_->Add(host_->native_view()->layer());

[sky, 2013/09/24 20:23:25]

In general I don't like temporarily adding layers this. Could you instead add a
View that has the clipping layer? Said view would always be present.

[sadrul, 2013/09/25 21:27:23]

The NativeView (aura::Window) attached to a NativeViewHost is parented to the
aura::Window hosting the Widget. I don't think we have a good way of parenting
an aura::Window to a View's layer (which makes it difficult to insert a View
that clips a child Window). I believe this is why Ryan is dancing with the
layers here.

If we wanted to avoid dealing directly with layers, then an alternate approach
could be to add a clipping Window to NativeViewHostAura. The clipping Window
becomes a child of the Widget's Window, and the NativeView becomes a child of
the clipping window. The NativeViewHostAura can then alter the clipping Window's
bounds as needed.

[sky, 2013/09/25 22:31:03]

Good point. I like the clipping Window approach. That way we aren't dynamically
adjusting things, which often times is error prone.

[rharrison, 2013/09/26 20:36:48]

Done.

+    orig_bounds_ = host_->native_view()->layer()->bounds();
+  }
+
+  installed_clip_ = true;
+
+  gfx::Rect layer_bounds = orig_bounds_;
+
+  clipping_layer_->SetBounds(gfx::Rect(layer_bounds.origin().x() + x,
+                                       layer_bounds.origin().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;
+
+  host_->native_view()->layer()->SetBounds(orig_bounds_);
+
+  clipping_layer_->parent()->Add(host_->native_view()->layer());
+  host_->native_view()->layer()->parent()->Remove(clipping_layer_.get());
+
   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 {
+    host_->native_view()->SetBounds(gfx::Rect(x, y, 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(
+    gfx::Rect input_rect,
+    gfx::Rect native_rect) const {
+  int new_x = input_rect.origin().x() +
+      gfx::ToRoundedInt(GetWidthFactor() * (input_rect.width() -
+                                            native_rect.width()));
+  int new_y = input_rect.origin().y() +
+      gfx::ToRoundedInt(GetHeightFactor() * (input_rect.height() -
+                                             native_rect.height()));
+  return gfx::Point(new_x, new_y);
+}
+
+gfx::Point NativeViewHostAura::CalculateClipOrigin(
+    gfx::Rect input_rect,
+    gfx::Rect native_rect) const {
+  int new_x = gfx::ToRoundedInt(GetWidthFactor() * (input_rect.width() -
+                                                    native_rect.width()));
+  int new_y = gfx::ToRoundedInt(GetHeightFactor() * (input_rect.height() -
+                                                     native_rect.height()));
+  return gfx::Point(new_x, new_y);
+}
+
+float NativeViewHostAura::GetWidthFactor() const {
+  float ret_val;
+  switch (host_->fast_resize_gravity()) {
+    case FAST_RESIZE_GRAVITY_NORTHWEST:
+      ret_val = 0.0;
+      break;
+    case FAST_RESIZE_GRAVITY_NORTH:
+      ret_val = 0.5;
+      break;
+    case FAST_RESIZE_GRAVITY_NORTHEAST:
+      ret_val = 1.0;
+      break;
+    case FAST_RESIZE_GRAVITY_EAST:
+      ret_val = 1.0;
+      break;
+    case FAST_RESIZE_GRAVITY_SOUTHEAST:
+      ret_val = 1.0;
+      break;
+    case FAST_RESIZE_GRAVITY_SOUTH:
+      ret_val = 0.5;
+      break;
+    case FAST_RESIZE_GRAVITY_SOUTHWEST:
+      ret_val = 0.0;
+      break;
+    case FAST_RESIZE_GRAVITY_WEST:
+      ret_val = 0.0;
+      break;
+    case FAST_RESIZE_GRAVITY_CENTER:
+      ret_val = 0.5;
+      break;
+    default:
+      NOTREACHED();
+  };

[sky, 2013/09/24 20:23:25]

nit: no ; (same on 245 below). Also, remove the default switch so you get
compile error.

[rharrison, 2013/09/26 20:36:48]

Done.

+  return ret_val;
+}
+
+float NativeViewHostAura::GetHeightFactor() const {
+  float ret_val;
+  switch (host_->fast_resize_gravity()) {
+    case FAST_RESIZE_GRAVITY_NORTHWEST:
+      ret_val = 0.0;
+      break;
+    case FAST_RESIZE_GRAVITY_NORTH:
+      ret_val = 0.0;
+      break;
+    case FAST_RESIZE_GRAVITY_NORTHEAST:
+      ret_val = 0.0;
+      break;
+    case FAST_RESIZE_GRAVITY_EAST:
+      ret_val = 0.5;
+      break;
+    case FAST_RESIZE_GRAVITY_SOUTHEAST:
+      ret_val = 1.0;
+      break;
+    case FAST_RESIZE_GRAVITY_SOUTH:
+      ret_val = 1.0;
+      break;
+    case FAST_RESIZE_GRAVITY_SOUTHWEST:
+      ret_val = 1.0;
+      break;
+    case FAST_RESIZE_GRAVITY_WEST:
+      ret_val = 0.5;
+      break;
+    case FAST_RESIZE_GRAVITY_CENTER:
+      ret_val = 0.5;
+      break;
+    default:
+      NOTREACHED();
+  };
+  return ret_val;
+}
+
+
 }  // namespace views