// 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 "content/browser/web_contents/web_contents_view_aura.h"

#include "base/auto_reset.h"
#include "base/metrics/histogram.h"
#include "base/utf_string_conversions.h"
#include "content/browser/renderer_host/dip_util.h"
#include "content/browser/renderer_host/overscroll_controller.h"
#include "content/browser/renderer_host/render_view_host_factory.h"
#include "content/browser/renderer_host/render_view_host_impl.h"
#include "content/browser/renderer_host/render_widget_host_impl.h"
#include "content/browser/renderer_host/render_widget_host_view_aura.h"
#include "content/browser/web_contents/interstitial_page_impl.h"
#include "content/browser/web_contents/navigation_entry_impl.h"
#include "content/browser/web_contents/web_contents_impl.h"
#include "content/public/browser/notification_observer.h"
#include "content/public/browser/notification_registrar.h"
#include "content/public/browser/notification_source.h"
#include "content/public/browser/notification_types.h"
#include "content/public/browser/overscroll_configuration.h"
#include "content/public/browser/render_view_host.h"
#include "content/public/browser/render_widget_host.h"
#include "content/public/browser/render_widget_host_view.h"
#include "content/public/browser/web_contents_delegate.h"
#include "content/public/browser/web_contents_observer.h"
#include "content/public/browser/web_contents_view_delegate.h"
#include "content/public/browser/web_drag_dest_delegate.h"
#include "third_party/WebKit/Source/WebKit/chromium/public/WebInputEvent.h"
#include "third_party/skia/include/effects/SkGradientShader.h"
#include "ui/aura/client/aura_constants.h"
#include "ui/aura/client/drag_drop_client.h"
#include "ui/aura/client/drag_drop_delegate.h"
#include "ui/aura/root_window.h"
#include "ui/aura/root_window_observer.h"
#include "ui/aura/window.h"
#include "ui/aura/window_observer.h"
#include "ui/base/clipboard/custom_data_helper.h"
#include "ui/base/dragdrop/drag_drop_types.h"
#include "ui/base/dragdrop/drag_utils.h"
#include "ui/base/dragdrop/os_exchange_data.h"
#include "ui/base/events/event.h"
#include "ui/base/events/event_utils.h"
#include "ui/base/hit_test.h"
#include "ui/compositor/layer.h"
#include "ui/compositor/scoped_layer_animation_settings.h"
#include "ui/gfx/canvas.h"
#include "ui/gfx/image/image.h"
#include "ui/gfx/image/image_png_rep.h"
#include "ui/gfx/image/image_skia.h"
#include "ui/gfx/screen.h"
#include "ui/gfx/skia_util.h"
#include "webkit/glue/webdropdata.h"

#if defined(OS_WIN)
#include "ui/base/clipboard/clipboard_util_win.h"
#endif

namespace content {
WebContentsViewPort* CreateWebContentsView(
    WebContentsImpl* web_contents,
    WebContentsViewDelegate* delegate,
    RenderViewHostDelegateView** render_view_host_delegate_view) {
  WebContentsViewAura* rv = new WebContentsViewAura(web_contents, delegate);
  *render_view_host_delegate_view = rv;
  return rv;
}

namespace {

const SkColor kShadowLightColor = SkColorSetARGB(0x0, 0, 0, 0);
const SkColor kShadowDarkColor = SkColorSetARGB(0x70, 0, 0, 0);
const int kShadowThick = 7;

enum ShadowEdge {
  SHADOW_NONE,
  SHADOW_LEFT,
  SHADOW_RIGHT,
  SHADOW_TOP,
  SHADOW_BOTTOM
};

bool ShouldNavigateForward(const NavigationController& controller,
                           OverscrollMode mode) {
  return mode == (base::i18n::IsRTL() ? OVERSCROLL_EAST : OVERSCROLL_WEST) &&
         controller.CanGoForward();
}

bool ShouldNavigateBack(const NavigationController& controller,
                        OverscrollMode mode) {
  return mode == (base::i18n::IsRTL() ? OVERSCROLL_WEST : OVERSCROLL_EAST) &&
         controller.CanGoBack();
}

// The window delegate for the overscroll window. This redirects trackpad events
// to the web-contents window. The delegate destroys itself when the window is
// destroyed.
class OverscrollWindowDelegate : public aura::WindowDelegate {
 public:
  OverscrollWindowDelegate(WebContentsImpl* web_contents,
                           OverscrollMode overscroll_mode)
      : web_contents_(web_contents),
        show_shadow_(false),
        forward_events_(true) {
    const NavigationControllerImpl& controller = web_contents->GetController();
    const NavigationEntryImpl* entry = NULL;
    if (ShouldNavigateForward(controller, overscroll_mode)) {
      entry = NavigationEntryImpl::FromNavigationEntry(
          controller.GetEntryAtOffset(1));
    } else if (ShouldNavigateBack(controller, overscroll_mode)) {
      entry = NavigationEntryImpl::FromNavigationEntry(
          controller.GetEntryAtOffset(-1));
    }
    if (!entry || !entry->screenshot())
      return;

    std::vector<gfx::ImagePNGRep> image_reps;
    image_reps.push_back(gfx::ImagePNGRep(entry->screenshot(),
          ui::GetScaleFactorForNativeView(web_contents_window())));
    image_ = gfx::Image(image_reps);
    if (image_.AsImageSkia().size() != web_contents_window()->bounds().size())
      image_ = gfx::Image();
  }

  bool has_screenshot() const { return !image_.IsEmpty(); }

  void set_show_shadow(bool show) {
    show_shadow_ = show;
  }

  void stop_forwarding_events() { forward_events_ = false; }

 private:
  virtual ~OverscrollWindowDelegate() {}

  aura::Window* web_contents_window() {
    return web_contents_->GetView()->GetContentNativeView();
  }

  // aura::WindowDelegate implementation:
  virtual gfx::Size GetMinimumSize() const OVERRIDE {
    return gfx::Size();
  }

  virtual gfx::Size GetMaximumSize() const OVERRIDE {
    return gfx::Size();
  }

  virtual void OnBoundsChanged(const gfx::Rect& old_bounds,
                               const gfx::Rect& new_bounds) OVERRIDE {
  }

  virtual gfx::NativeCursor GetCursor(const gfx::Point& point) OVERRIDE {
    return gfx::kNullCursor;
  }

  virtual int GetNonClientComponent(const gfx::Point& point) const OVERRIDE {
    return HTNOWHERE;
  }

  virtual bool ShouldDescendIntoChildForEventHandling(
      aura::Window* child,
      const gfx::Point& location) OVERRIDE {
    return false;
  }

  virtual bool CanFocus() OVERRIDE {
    return false;
  }

  virtual void OnCaptureLost() OVERRIDE {
  }

  virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE {
    if (show_shadow_) {
      canvas->Save();
      canvas->Translate(gfx::Vector2d(kShadowThick, 0));
    }
    if (image_.IsEmpty())
      canvas->DrawColor(SK_ColorGRAY);
    else
      canvas->DrawImageInt(image_.AsImageSkia(), 0, 0);

    if (show_shadow_) {
      canvas->Restore();
      SkPoint points[2];
      points[0].iset(0, 0);
      points[1].iset(kShadowThick, 0);
      SkColor colors[2] = { kShadowLightColor, kShadowDarkColor };
      skia::RefPtr<SkShader> shader = skia::AdoptRef(
          SkGradientShader::CreateLinear(points, colors, NULL,
              arraysize(points), SkShader::kRepeat_TileMode, NULL));

      SkRect rect = { SkIntToScalar(0),
                      SkIntToScalar(0),
                      SkIntToScalar(kShadowThick),
                      SkIntToScalar(web_contents_window()->bounds().height()) };
      SkPaint paint;
      paint.setShader(shader.get());
      canvas->sk_canvas()->drawRect(rect, paint);
    }
  }

  virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE {
  }

  virtual void OnWindowDestroying() OVERRIDE {
  }

  virtual void OnWindowDestroyed() OVERRIDE {
    delete this;
  }

  virtual void OnWindowTargetVisibilityChanged(bool visible) OVERRIDE {
  }

  virtual bool HasHitTestMask() const OVERRIDE {
    return false;
  }

  virtual void GetHitTestMask(gfx::Path* mask) const OVERRIDE {
  }

  virtual scoped_refptr<ui::Texture> CopyTexture() OVERRIDE {
    return scoped_refptr<ui::Texture>();
  }

  // Overridden from ui::EventHandler.
  virtual void OnScrollEvent(ui::ScrollEvent* event) OVERRIDE {
    if (forward_events_ && web_contents_window())
      web_contents_window()->delegate()->OnScrollEvent(event);
  }

  virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE {
    if (forward_events_ && web_contents_window())
      web_contents_window()->delegate()->OnGestureEvent(event);
  }

  WebContents* web_contents_;
  gfx::Image image_;
  bool show_shadow_;

  // The window is displayed both during the gesture, and after the gesture
  // while the navigation is in progress. During the gesture, it is necessary to
  // forward input events to the content page (e.g. when the overscroll window
  // slides under the cursor and starts receiving scroll events). However, once
  // the gesture is complete, and the window is being displayed as an overlay
  // window during navigation, events should not be forwarded anymore.
  bool forward_events_;

  DISALLOW_COPY_AND_ASSIGN(OverscrollWindowDelegate);
};

// Listens to all mouse drag events during a drag and drop and sends them to
// the renderer.
class WebDragSourceAura : public MessageLoopForUI::Observer,
                          public NotificationObserver {
 public:
  WebDragSourceAura(aura::Window* window, WebContentsImpl* contents)
      : window_(window),
        contents_(contents) {
    MessageLoopForUI::current()->AddObserver(this);
    registrar_.Add(this, NOTIFICATION_WEB_CONTENTS_DISCONNECTED,
                   Source<WebContents>(contents));
  }

  virtual ~WebDragSourceAura() {
    MessageLoopForUI::current()->RemoveObserver(this);
  }

  // MessageLoop::Observer implementation:
  virtual base::EventStatus WillProcessEvent(
      const base::NativeEvent& event) OVERRIDE {
    return base::EVENT_CONTINUE;
  }
  virtual void DidProcessEvent(const base::NativeEvent& event) OVERRIDE {
    if (!contents_)
      return;
    ui::EventType type = ui::EventTypeFromNative(event);
    RenderViewHost* rvh = NULL;
    switch (type) {
      case ui::ET_MOUSE_DRAGGED:
        rvh = contents_->GetRenderViewHost();
        if (rvh) {
          gfx::Point screen_loc_in_pixel = ui::EventLocationFromNative(event);
          gfx::Point screen_loc = ConvertPointToDIP(rvh->GetView(),
              screen_loc_in_pixel);
          gfx::Point client_loc = screen_loc;
          aura::Window* window = rvh->GetView()->GetNativeView();
          aura::Window::ConvertPointToTarget(window->GetRootWindow(),
              window, &client_loc);
          rvh->DragSourceMovedTo(client_loc.x(), client_loc.y(),
              screen_loc.x(), screen_loc.y());
        }
        break;
      default:
        break;
    }
  }

  virtual void Observe(int type,
      const NotificationSource& source,
      const NotificationDetails& details) OVERRIDE {
    if (type != NOTIFICATION_WEB_CONTENTS_DISCONNECTED)
      return;

    // Cancel the drag if it is still in progress.
    aura::client::DragDropClient* dnd_client =
        aura::client::GetDragDropClient(window_->GetRootWindow());
    if (dnd_client && dnd_client->IsDragDropInProgress())
      dnd_client->DragCancel();

    window_ = NULL;
    contents_ = NULL;
  }

  aura::Window* window() const { return window_; }

 private:
  aura::Window* window_;
  WebContentsImpl* contents_;
  NotificationRegistrar registrar_;

  DISALLOW_COPY_AND_ASSIGN(WebDragSourceAura);
};

// Utility to fill a ui::OSExchangeDataProvider object from WebDropData.
void PrepareDragData(const WebDropData& drop_data,
                     ui::OSExchangeData::Provider* provider) {
  if (!drop_data.text.string().empty())
    provider->SetString(drop_data.text.string());
  if (drop_data.url.is_valid())
    provider->SetURL(drop_data.url, drop_data.url_title);
  if (!drop_data.html.string().empty())
    provider->SetHtml(drop_data.html.string(), drop_data.html_base_url);
  if (!drop_data.filenames.empty()) {
    std::vector<ui::OSExchangeData::FileInfo> filenames;
    for (std::vector<WebDropData::FileInfo>::const_iterator it =
             drop_data.filenames.begin();
         it != drop_data.filenames.end(); ++it) {
      filenames.push_back(
          ui::OSExchangeData::FileInfo(
              base::FilePath::FromUTF8Unsafe(UTF16ToUTF8(it->path)),
              base::FilePath::FromUTF8Unsafe(UTF16ToUTF8(it->display_name))));
    }
    provider->SetFilenames(filenames);
  }
  if (!drop_data.custom_data.empty()) {
    Pickle pickle;
    ui::WriteCustomDataToPickle(drop_data.custom_data, &pickle);
#if defined(OS_WIN)
    provider->SetPickledData(
        ui::ClipboardUtil::GetWebCustomDataFormat()->cfFormat, pickle);
#else
    provider->SetPickledData(ui::Clipboard::GetWebCustomDataFormatType(),
                             pickle);
#endif
  }
}

// Utility to fill a WebDropData object from ui::OSExchangeData.
void PrepareWebDropData(WebDropData* drop_data,
                        const ui::OSExchangeData& data) {
  string16 plain_text;
  data.GetString(&plain_text);
  if (!plain_text.empty())
    drop_data->text = NullableString16(plain_text, false);

  GURL url;
  string16 url_title;
  data.GetURLAndTitle(&url, &url_title);
  if (url.is_valid()) {
    drop_data->url = url;
    drop_data->url_title = url_title;
  }

  string16 html;
  GURL html_base_url;
  data.GetHtml(&html, &html_base_url);
  if (!html.empty())
    drop_data->html = NullableString16(html, false);
  if (html_base_url.is_valid())
    drop_data->html_base_url = html_base_url;

  std::vector<ui::OSExchangeData::FileInfo> files;
  if (data.GetFilenames(&files) && !files.empty()) {
    for (std::vector<ui::OSExchangeData::FileInfo>::const_iterator
             it = files.begin(); it != files.end(); ++it) {
      drop_data->filenames.push_back(
          WebDropData::FileInfo(
              UTF8ToUTF16(it->path.AsUTF8Unsafe()),
              UTF8ToUTF16(it->display_name.AsUTF8Unsafe())));
    }
  }

  Pickle pickle;
#if defined(OS_WIN)
  if (data.GetPickledData(ui::ClipboardUtil::GetWebCustomDataFormat()->cfFormat,
                          &pickle))
#else
  if (data.GetPickledData(ui::Clipboard::GetWebCustomDataFormatType(),
                          &pickle))
#endif
    ui::ReadCustomDataIntoMap(pickle.data(), pickle.size(),
                              &drop_data->custom_data);
}

// Utilities to convert between WebKit::WebDragOperationsMask and
// ui::DragDropTypes.
int ConvertFromWeb(WebKit::WebDragOperationsMask ops) {
  int drag_op = ui::DragDropTypes::DRAG_NONE;
  if (ops & WebKit::WebDragOperationCopy)
    drag_op |= ui::DragDropTypes::DRAG_COPY;
  if (ops & WebKit::WebDragOperationMove)
    drag_op |= ui::DragDropTypes::DRAG_MOVE;
  if (ops & WebKit::WebDragOperationLink)
    drag_op |= ui::DragDropTypes::DRAG_LINK;
  return drag_op;
}

WebKit::WebDragOperationsMask ConvertToWeb(int drag_op) {
  int web_drag_op = WebKit::WebDragOperationNone;
  if (drag_op & ui::DragDropTypes::DRAG_COPY)
    web_drag_op |= WebKit::WebDragOperationCopy;
  if (drag_op & ui::DragDropTypes::DRAG_MOVE)
    web_drag_op |= WebKit::WebDragOperationMove;
  if (drag_op & ui::DragDropTypes::DRAG_LINK)
    web_drag_op |= WebKit::WebDragOperationLink;
  return (WebKit::WebDragOperationsMask) web_drag_op;
}

int ConvertAuraEventFlagsToWebInputEventModifiers(int aura_event_flags) {
  int web_input_event_modifiers = 0;
  if (aura_event_flags & ui::EF_SHIFT_DOWN)
    web_input_event_modifiers |= WebKit::WebInputEvent::ShiftKey;
  if (aura_event_flags & ui::EF_CONTROL_DOWN)
    web_input_event_modifiers |= WebKit::WebInputEvent::ControlKey;
  if (aura_event_flags & ui::EF_ALT_DOWN)
    web_input_event_modifiers |= WebKit::WebInputEvent::AltKey;
  if (aura_event_flags & ui::EF_COMMAND_DOWN)
    web_input_event_modifiers |= WebKit::WebInputEvent::MetaKey;
  return web_input_event_modifiers;
}

}  // namespace

// ShadowWindow is used to paint shadows around a content window.
// A ShadowWindow destroys itself when the content window is destroyed, and
// updates its bounds to make sure the shadows are painted in the correct size.
class ShadowWindow : public aura::Window,
                     public aura::WindowObserver {
 public:
  explicit ShadowWindow(aura::Window* window)
      : aura::Window(NULL),
        window_(window),
        edge_(SHADOW_NONE) {
    SetType(aura::client::WINDOW_TYPE_CONTROL);
    SetTransparent(true);
    set_owned_by_parent(false);
    Init(ui::LAYER_NOT_DRAWN);
    layer()->SetMasksToBounds(false);

    AddChild(window);
    window_->AddObserver(this);

    SetBounds(gfx::Rect(window->bounds().size()));
    Show();
  }

  void SetShadowEdge(ShadowEdge edge) {
    edge_ = edge;
    if (edge_ == SHADOW_NONE) {
      shadow_.reset();
      return;
    }

    shadow_.reset(new ui::Layer(ui::LAYER_TEXTURED));
    shadow_->set_delegate(this);
    shadow_->SetFillsBoundsOpaquely(false);
    layer()->Add(shadow_.get());
    layer()->StackBelow(shadow_.get(), window_->layer());
    UpdateShadowBounds();
  }

 private:
  friend class base::DeleteHelper<content::ShadowWindow>;

  virtual ~ShadowWindow() {
  }

  void UpdateShadowBounds() {
    if (!shadow_.get())
      return;
    gfx::Rect bound;
    switch (edge_) {
      case SHADOW_LEFT:
        bound.SetRect(-kShadowThick, 0, kShadowThick, bounds().height());
        break;
      case SHADOW_RIGHT:
        bound.SetRect(bounds().right(), 0, kShadowThick, bounds().height());
        break;
      case SHADOW_TOP:
        bound.SetRect(0, -kShadowThick, bounds().width(), kShadowThick);
        break;
      case SHADOW_BOTTOM:
        bound.SetRect(0, bounds().bottom(), bounds().width(), kShadowThick);
        break;
      case SHADOW_NONE:
        NOTREACHED();
    }
    shadow_->SetBounds(bound);
  }

  // Overridden from aura::WindowObserver:
  virtual void OnWindowBoundsChanged(Window* window,
                                     const gfx::Rect& old_bounds,
                                     const gfx::Rect& new_bounds) OVERRIDE {
    SetBounds(gfx::Rect(new_bounds.size()));
    UpdateShadowBounds();
  }

  virtual void OnWindowDestroying(aura::Window* window) OVERRIDE {
    DCHECK_EQ(window, window_);
    window_->RemoveObserver(this);
    window_ = NULL;
    MessageLoop::current()->DeleteSoon(FROM_HERE, this);
  }

  // Overridden from ui::LayerDelegate:
  virtual void OnPaintLayer(gfx::Canvas* canvas) OVERRIDE {
    SkPoint points[2];
    SkColor colors[2];

    points[0].iset(0, 0);
    switch (edge_) {
      case SHADOW_LEFT:
      case SHADOW_RIGHT:
        points[1].iset(shadow_->bounds().width(), 0);
        break;

      case SHADOW_TOP:
      case SHADOW_BOTTOM:
        points[1].iset(0, shadow_->bounds().height());
        break;

      default:
        NOTREACHED();
    }

    switch (edge_) {
      case SHADOW_LEFT:
      case SHADOW_TOP:
        colors[0] = kShadowLightColor;
        colors[1] = kShadowDarkColor;
        break;

      case SHADOW_RIGHT:
      case SHADOW_BOTTOM:
        colors[0] = kShadowDarkColor;
        colors[1] = kShadowLightColor;
        break;

      default:
        NOTREACHED();
    }

    skia::RefPtr<SkShader> shader = skia::AdoptRef(
        SkGradientShader::CreateLinear(points, colors, NULL,
            arraysize(points), SkShader::kRepeat_TileMode, NULL));

    SkPaint paint;
    paint.setShader(shader.get());
    canvas->sk_canvas()->drawRect(gfx::RectToSkRect(bounds()), paint);
  }

  aura::Window* window_;
  scoped_ptr<ui::Layer> shadow_;
  ShadowEdge edge_;

  DISALLOW_COPY_AND_ASSIGN(ShadowWindow);
};

// When a history navigation is triggered at the end of an overscroll
// navigation, it is necessary to show the history-screenshot until the page is
// done navigating and painting. This class accomplishes this by showing the
// screenshot window on top of the page until the page has completed loading and
// painting.
class OverscrollNavigationOverlay :
    public RenderWidgetHostViewAura::PaintObserver {
 public:
  OverscrollNavigationOverlay()
      : view_(NULL),
        loading_complete_(false),
        received_paint_update_(false),
        compositor_updated_(false),
        has_screenshot_(false),
        need_paint_update_(true) {
  }

  virtual ~OverscrollNavigationOverlay() {
    if (view_)
      view_->set_paint_observer(NULL);
  }

  bool has_window() const { return !!window_.get(); }

  void StartObservingView(RenderWidgetHostViewAura* view) {
    if (view_)
      view_->set_paint_observer(NULL);

    loading_complete_ = false;
    received_paint_update_ = false;
    compositor_updated_ = false;
    view_ = view;
    view_->set_paint_observer(this);

    // Make sure the overlay window is on top.
    if (window_.get() && window_->parent())
      window_->parent()->StackChildAtTop(window_.get());
  }

  void SetOverlayWindow(scoped_ptr<aura::Window> window, bool has_screenshot) {
    window_ = window.Pass();
    if (window_.get() && window_->parent())
      window_->parent()->StackChildAtTop(window_.get());
    has_screenshot_ = has_screenshot;
  }

  void SetupForTesting() {
    need_paint_update_ = false;
  }

 private:
  // Stop observing the page if the page-load has completed and the page has
  // been painted.
  void StopObservingIfDone() {
    // If there is a screenshot displayed in the overlay window, then wait for
    // the navigated page to complete loading and some paint update before
    // hiding the overlay.
    // If there is no screenshot in the overlay window, then hide this view
    // as soon as there is any new painting notification.
    if ((need_paint_update_ && !received_paint_update_) ||
        (has_screenshot_ && !loading_complete_)) {
      return;
    }

    window_.reset();
    if (view_) {
      view_->set_paint_observer(NULL);
      view_ = NULL;
    }
  }

  // Overridden from RenderWidgetHostViewAura::PaintObserver:
  virtual void OnPaintComplete() OVERRIDE {
    received_paint_update_ = true;
    StopObservingIfDone();
  }

  virtual void OnCompositingComplete() OVERRIDE {
    received_paint_update_ = compositor_updated_;
    StopObservingIfDone();
  }

  virtual void OnUpdateCompositorContent() OVERRIDE {
    compositor_updated_ = true;
  }

  virtual void OnPageLoadComplete() OVERRIDE {
    loading_complete_ = true;
    StopObservingIfDone();
  }

  virtual void OnViewDestroyed() OVERRIDE {
    DCHECK(view_);
    view_->set_paint_observer(NULL);
    view_ = NULL;
  }

  scoped_ptr<aura::Window> window_;
  RenderWidgetHostViewAura* view_;
  bool loading_complete_;
  bool received_paint_update_;
  bool compositor_updated_;
  bool has_screenshot_;

  // During tests, the aura windows don't get any paint updates. So the overlay
  // container keeps waiting for a paint update it never receives, causing a
  // timeout. So during tests, disable the wait for paint updates.
  bool need_paint_update_;

  DISALLOW_COPY_AND_ASSIGN(OverscrollNavigationOverlay);
};

class WebContentsViewAura::WindowObserver
    : public aura::WindowObserver, public aura::RootWindowObserver {
 public:
  explicit WindowObserver(WebContentsViewAura* view)
      : view_(view),
        parent_(NULL) {
    view_->window_->AddObserver(this);
  }

  virtual ~WindowObserver() {
    view_->window_->RemoveObserver(this);
    if (view_->window_->GetRootWindow())
      view_->window_->GetRootWindow()->RemoveRootWindowObserver(this);
    if (parent_)
      parent_->RemoveObserver(this);
  }

  // Overridden from aura::WindowObserver:
  virtual void OnWindowParentChanged(aura::Window* window,
                                     aura::Window* parent) OVERRIDE {
    if (window == parent_)
      return;
    if (parent_)
      parent_->RemoveObserver(this);
    parent_ = parent;
    if (parent)
      parent->AddObserver(this);
  }

  virtual void OnWindowBoundsChanged(aura::Window* window,
                                     const gfx::Rect& old_bounds,
                                     const gfx::Rect& new_bounds) OVERRIDE {
    SendScreenRects();
  }

  virtual void OnWindowAddedToRootWindow(aura::Window* window) OVERRIDE {
    if (window != parent_)
      window->GetRootWindow()->AddRootWindowObserver(this);
  }

  virtual void OnWindowRemovingFromRootWindow(aura::Window* window) OVERRIDE {
    if (window != parent_)
      window->GetRootWindow()->RemoveRootWindowObserver(this);
  }

  // Overridden RootWindowObserver:
  virtual void OnRootWindowMoved(const aura::RootWindow* root,
                                 const gfx::Point& new_origin) OVERRIDE {
    // This is for the desktop case (i.e. Aura desktop).
    SendScreenRects();
  }

 private:
  void SendScreenRects() {
    RenderWidgetHostImpl::From(view_->web_contents_->GetRenderViewHost())->
        SendScreenRects();
  }

  WebContentsViewAura* view_;

  // We cache the old parent so that we can unregister when it's not the parent
  // anymore.
  aura::Window* parent_;

  DISALLOW_COPY_AND_ASSIGN(WindowObserver);
};

#if defined(OS_WIN)
// Constrained windows are added as children of the WebContent's view which may
// overlap with windowed NPAPI plugins. In that case, tell the RWHV so that it
// can update the plugins' cutout rects accordingly.
class WebContentsViewAura::ChildWindowObserver : public aura::WindowObserver,
                                                 public WebContentsObserver {
 public:
  explicit ChildWindowObserver(WebContentsViewAura* view)
      : WebContentsObserver(view->web_contents_),
        view_(view),
        web_contents_destroyed_(false) {
    view_->window_->AddObserver(this);
  }

  virtual ~ChildWindowObserver() {
    view_->window_->RemoveObserver(this);
    const aura::Window::Windows& children = view_->window_->children();
    for (size_t i = 0; i < children.size(); ++i)
      children[i]->RemoveObserver(this);
  }

  // Overridden from aura::WindowObserver:
  virtual void OnWindowAdded(aura::Window* new_window) OVERRIDE {
    // If new child windows are added to the WebContent's view, tell the RWHV.
    // We also start watching them to know when their size is updated. Of
    // course, ignore the shadow window that contains the RWHV and child windows
    // of the child windows that we are watching.
    if (new_window->parent() == view_->window_ &&
        new_window != view_->content_container_) {
      new_window->AddObserver(this);
      UpdateConstrainedWindows(NULL);
    }
  }

  virtual void OnWillRemoveWindow(aura::Window* window) OVERRIDE {
    if (window->parent() == view_->window_ &&
        window != view_->content_container_) {
      window->RemoveObserver(this);
      UpdateConstrainedWindows(window);
    }
  }

  virtual void OnWindowBoundsChanged(aura::Window* window,
                                     const gfx::Rect& old_bounds,
                                     const gfx::Rect& new_bounds) OVERRIDE {
    if (window->parent() == view_->window_ &&
        window != view_->content_container_) {
      UpdateConstrainedWindows(NULL);
    }
  }

  // Overridden from WebContentsObserver:
  virtual void WebContentsDestroyed(WebContents* web_contents) OVERRIDE {
    web_contents_destroyed_ = true;
  }

 private:
  void UpdateConstrainedWindows(aura::Window* exclude) {
    if (RenderViewHostFactory::has_factory())
      return;  // Can't cast to RenderWidgetHostViewAura in unit tests.

    if (web_contents_destroyed_)
      return;

    RenderWidgetHostViewAura* view = static_cast<RenderWidgetHostViewAura*>(
        view_->web_contents_->GetRenderWidgetHostView());
    if (!view)
      return;

    std::vector<gfx::Rect> constrained_windows;
    const aura::Window::Windows& children = view_->window_->children();
    for (size_t i = 0; i < children.size(); ++i) {
      if (children[i] != view_->content_container_ && children[i] != exclude)
        constrained_windows.push_back(children[i]->GetBoundsInRootWindow());
    }

    view->UpdateConstrainedWindowRects(constrained_windows);
  }

  WebContentsViewAura* view_;
  bool web_contents_destroyed_;

  DISALLOW_COPY_AND_ASSIGN(ChildWindowObserver);
};
#endif

////////////////////////////////////////////////////////////////////////////////
// WebContentsViewAura, public:

WebContentsViewAura::WebContentsViewAura(
    WebContentsImpl* web_contents,
    WebContentsViewDelegate* delegate)
    : web_contents_(web_contents),
      delegate_(delegate),
      current_drag_op_(WebKit::WebDragOperationNone),
      drag_dest_delegate_(NULL),
      current_rvh_for_drag_(NULL),
      content_container_(NULL),
      overscroll_change_brightness_(false),
      current_overscroll_gesture_(OVERSCROLL_NONE),
      completed_overscroll_gesture_(OVERSCROLL_NONE) {
}

////////////////////////////////////////////////////////////////////////////////
// WebContentsViewAura, private:

WebContentsViewAura::~WebContentsViewAura() {
  if (!window_)
    return;

  window_observer_.reset();
#if defined(OS_WIN)
  child_window_observer_.reset();
#endif
  // Window needs a valid delegate during its destructor, so we explicitly
  // delete it here.
  window_.reset();
}

void WebContentsViewAura::SetupOverlayWindowForTesting() {
  if (navigation_overlay_.get())
    navigation_overlay_->SetupForTesting();
}

void WebContentsViewAura::SizeChangedCommon(const gfx::Size& size) {
  if (web_contents_->GetInterstitialPage())
    web_contents_->GetInterstitialPage()->SetSize(size);
  RenderWidgetHostView* rwhv =
      web_contents_->GetRenderWidgetHostView();
  if (rwhv)
    rwhv->SetSize(size);
}

void WebContentsViewAura::EndDrag(WebKit::WebDragOperationsMask ops) {
  aura::RootWindow* root_window = GetNativeView()->GetRootWindow();
  gfx::Point screen_loc =
      gfx::Screen::GetScreenFor(GetNativeView())->GetCursorScreenPoint();
  gfx::Point client_loc = screen_loc;
  RenderViewHost* rvh = web_contents_->GetRenderViewHost();
  aura::Window* window = rvh->GetView()->GetNativeView();
  aura::Window::ConvertPointToTarget(root_window, window, &client_loc);
  rvh->DragSourceEndedAt(client_loc.x(), client_loc.y(), screen_loc.x(),
      screen_loc.y(), ops);
}

void WebContentsViewAura::PrepareOverscrollWindow() {
  // If there is an existing |overscroll_window_| which is in the middle of an
  // animation, then destroying the window here causes the animation to be
  // completed immidiately, which triggers |OnImplicitAnimationsCompleted()|
  // callback, and that tries to reset |overscroll_window_| again, causing a
  // double-free. So use a temporary variable here.
  if (overscroll_window_.get()) {
    base::AutoReset<OverscrollMode> reset_state(&current_overscroll_gesture_,
                                                current_overscroll_gesture_);
    scoped_ptr<aura::Window> reset_window(overscroll_window_.release());
  }

  OverscrollWindowDelegate* overscroll_delegate = new OverscrollWindowDelegate(
      web_contents_,
      current_overscroll_gesture_);
  overscroll_window_.reset(new aura::Window(overscroll_delegate));
  overscroll_window_->SetType(aura::client::WINDOW_TYPE_CONTROL);
  overscroll_window_->SetTransparent(true);
  overscroll_window_->Init(ui::LAYER_TEXTURED);
  overscroll_window_->layer()->SetMasksToBounds(true);
  overscroll_window_->SetName("OverscrollOverlay");

  overscroll_change_brightness_ = overscroll_delegate->has_screenshot();
  window_->AddChild(overscroll_window_.get());

  gfx::Rect bounds = gfx::Rect(window_->bounds().size());
  if (ShouldNavigateForward(web_contents_->GetController(),
                            current_overscroll_gesture_)) {
    // The overlay will be sliding in from the right edge towards the left in
    // non-RTL, or sliding in from the left edge towards the right in RTL.
    // So position the overlay window accordingly.
    bounds.Offset(base::i18n::IsRTL() ? -bounds.width() : bounds.width(), 0);
  }

  if (GetWindowToAnimateForOverscroll() == overscroll_window_.get()) {
    overscroll_delegate->set_show_shadow(true);
    window_->StackChildAbove(overscroll_window_.get(), content_container_);
  } else {
    window_->StackChildBelow(overscroll_window_.get(), content_container_);

    switch (current_overscroll_gesture_) {
      case OVERSCROLL_EAST:
        content_container_->SetShadowEdge(SHADOW_LEFT);
        break;

      case OVERSCROLL_WEST:
        content_container_->SetShadowEdge(SHADOW_RIGHT);
        break;

      case OVERSCROLL_NORTH:
        content_container_->SetShadowEdge(SHADOW_BOTTOM);
        break;

      case OVERSCROLL_SOUTH:
        content_container_->SetShadowEdge(SHADOW_TOP);
        break;

      case OVERSCROLL_NONE:
      case OVERSCROLL_COUNT:
        NOTREACHED();
    }
  }

  UpdateOverscrollWindowBrightness(0.f);

  overscroll_window_->SetBounds(bounds);
  overscroll_window_->Show();
}

void WebContentsViewAura::PrepareContentWindowForOverscroll() {
  DCHECK(content_container_);
  DCHECK_EQ(content_container_, GetContentNativeView()->parent());

  aura::Window* content = content_container_;
  ui::ScopedLayerAnimationSettings settings(content->layer()->GetAnimator());
  settings.SetPreemptionStrategy(ui::LayerAnimator::IMMEDIATELY_SET_NEW_TARGET);
  content->SetTransform(gfx::Transform());
  content->layer()->SetLayerBrightness(0.f);
}

void WebContentsViewAura::ResetOverscrollTransform() {
  if (!web_contents_->GetRenderWidgetHostView())
    return;
  aura::Window* target = GetWindowToAnimateForOverscroll();
  if (!target)
    return;
  {
    ui::ScopedLayerAnimationSettings settings(target->layer()->GetAnimator());
    settings.SetPreemptionStrategy(
        ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
    settings.SetTweenType(ui::Tween::EASE_OUT);
    settings.AddObserver(this);
    target->SetTransform(gfx::Transform());
  }
  {
    ui::ScopedLayerAnimationSettings settings(target->layer()->GetAnimator());
    settings.SetPreemptionStrategy(
        ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
    settings.SetTweenType(ui::Tween::EASE_OUT);
    UpdateOverscrollWindowBrightness(0.f);
  }
}

void WebContentsViewAura::CompleteOverscrollNavigation(OverscrollMode mode) {
  if (!web_contents_->GetRenderWidgetHostView())
    return;

  // Animate out the current view first. Navigate to the requested history at
  // the end of the animation.
  if (current_overscroll_gesture_ == OVERSCROLL_NONE)
    return;

  UMA_HISTOGRAM_ENUMERATION("Overscroll.Navigated",
                            current_overscroll_gesture_, OVERSCROLL_COUNT);

  completed_overscroll_gesture_ = mode;
  aura::Window* target = GetWindowToAnimateForOverscroll();
  ui::ScopedLayerAnimationSettings settings(target->layer()->GetAnimator());
  settings.SetPreemptionStrategy(
      ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
  settings.SetTweenType(ui::Tween::EASE_OUT);
  settings.AddObserver(this);
  gfx::Transform transform;
  int content_width =
      web_contents_->GetRenderWidgetHostView()->GetViewBounds().width();
  int translate_x = mode == OVERSCROLL_WEST ? -content_width : content_width;
  transform.Translate(translate_x, 0);
  target->SetTransform(transform);
  UpdateOverscrollWindowBrightness(translate_x);
}

aura::Window* WebContentsViewAura::GetWindowToAnimateForOverscroll() {
  if (current_overscroll_gesture_ == OVERSCROLL_NONE)
    return NULL;

  return ShouldNavigateForward(web_contents_->GetController(),
                               current_overscroll_gesture_) ?
      overscroll_window_.get() : content_container_;
}

gfx::Vector2d WebContentsViewAura::GetTranslationForOverscroll(int delta_x,
                                                               int delta_y) {
  if (current_overscroll_gesture_ == OVERSCROLL_NORTH ||
      current_overscroll_gesture_ == OVERSCROLL_SOUTH) {
    // Ignore vertical overscroll.
    return gfx::Vector2d();
  }

  // For horizontal overscroll, scroll freely if a navigation is possible. Do a
  // resistive scroll otherwise.
  const NavigationControllerImpl& controller = web_contents_->GetController();
  const gfx::Rect& bounds = GetViewBounds();
  if (ShouldNavigateForward(controller, current_overscroll_gesture_))
    return gfx::Vector2d(std::max(-bounds.width(), delta_x), 0);
  else if (ShouldNavigateBack(controller, current_overscroll_gesture_))
    return gfx::Vector2d(std::min(bounds.width(), delta_x), 0);

  return gfx::Vector2d();
}

void WebContentsViewAura::PrepareOverscrollNavigationOverlay() {
  OverscrollWindowDelegate* delegate = static_cast<OverscrollWindowDelegate*>(
      overscroll_window_->delegate());
  delegate->set_show_shadow(false);
  delegate->stop_forwarding_events();
  overscroll_window_->SchedulePaintInRect(
      gfx::Rect(overscroll_window_->bounds().size()));
  navigation_overlay_->SetOverlayWindow(overscroll_window_.Pass(),
                                        delegate->has_screenshot());
  navigation_overlay_->StartObservingView(static_cast<
      RenderWidgetHostViewAura*>(web_contents_->GetRenderWidgetHostView()));
}

void WebContentsViewAura::UpdateOverscrollWindowBrightness(float delta_x) {
  if (!overscroll_change_brightness_)
    return;

  const float kBrightnessMin = -.1f;
  const float kBrightnessMax = -.01f;

  float ratio = fabs(delta_x) / GetViewBounds().width();
  ratio = std::min(1.f, ratio);
  if (base::i18n::IsRTL())
    ratio = 1.f - ratio;
  float brightness = current_overscroll_gesture_ == OVERSCROLL_WEST ?
      kBrightnessMin + ratio * (kBrightnessMax - kBrightnessMin) :
      kBrightnessMax - ratio * (kBrightnessMax - kBrightnessMin);
  brightness = std::max(kBrightnessMin, brightness);
  brightness = std::min(kBrightnessMax, brightness);
  aura::Window* window = GetWindowToAnimateForOverscroll();
  window->layer()->SetLayerBrightness(brightness);
}

////////////////////////////////////////////////////////////////////////////////
// WebContentsViewAura, WebContentsView implementation:

gfx::NativeView WebContentsViewAura::GetNativeView() const {
  return window_.get();
}

gfx::NativeView WebContentsViewAura::GetContentNativeView() const {
  RenderWidgetHostView* rwhv = web_contents_->GetRenderWidgetHostView();
  return rwhv ? rwhv->GetNativeView() : NULL;
}

gfx::NativeWindow WebContentsViewAura::GetTopLevelNativeWindow() const {
  return window_->GetToplevelWindow();
}

void WebContentsViewAura::GetContainerBounds(gfx::Rect *out) const {
  *out = window_->GetBoundsInScreen();
}

void WebContentsViewAura::OnTabCrashed(base::TerminationStatus status,
                                       int error_code) {
  // Set the focus to the parent because neither the view window nor this
  // window can handle key events.
  if (window_->HasFocus() && window_->parent())
    window_->parent()->Focus();
}

void WebContentsViewAura::SizeContents(const gfx::Size& size) {
  gfx::Rect bounds = window_->bounds();
  if (bounds.size() != size) {
    bounds.set_size(size);
    window_->SetBounds(bounds);
  } else {
    // Our size matches what we want but the renderers size may not match.
    // Pretend we were resized so that the renderers size is updated too.
    SizeChangedCommon(size);
  }
}

void WebContentsViewAura::Focus() {
  if (web_contents_->GetInterstitialPage()) {
    web_contents_->GetInterstitialPage()->Focus();
    return;
  }

  if (delegate_.get() && delegate_->Focus())
    return;

  RenderWidgetHostView* rwhv = web_contents_->GetRenderWidgetHostView();
  if (rwhv)
    rwhv->Focus();
}

void WebContentsViewAura::SetInitialFocus() {
  if (web_contents_->FocusLocationBarByDefault())
    web_contents_->SetFocusToLocationBar(false);
  else
    Focus();
}

void WebContentsViewAura::StoreFocus() {
  if (delegate_.get())
    delegate_->StoreFocus();
}

void WebContentsViewAura::RestoreFocus() {
  if (delegate_.get())
    delegate_->RestoreFocus();
}

WebDropData* WebContentsViewAura::GetDropData() const {
  return current_drop_data_.get();
}

gfx::Rect WebContentsViewAura::GetViewBounds() const {
  return window_->GetBoundsInScreen();
}

////////////////////////////////////////////////////////////////////////////////
// WebContentsViewAura, WebContentsViewPort implementation:

void WebContentsViewAura::CreateView(
    const gfx::Size& initial_size, gfx::NativeView context) {
  // NOTE: we ignore |initial_size| since in some cases it's wrong (such as
  // if the bookmark bar is not shown and you create a new tab). The right
  // value is set shortly after this, so its safe to ignore.

  window_.reset(new aura::Window(this));
  window_->set_owned_by_parent(false);
  window_->SetType(aura::client::WINDOW_TYPE_CONTROL);
  window_->SetTransparent(false);
  window_->Init(ui::LAYER_NOT_DRAWN);
  aura::RootWindow* root_window = context ? context->GetRootWindow() : NULL;
  if (root_window) {
    // There are places where there is no context currently because object
    // hierarchies are built before they're attached to a Widget. (See
    // views::WebView as an example; GetWidget() returns NULL at the point
    // where we are created.)
    //
    // It should be OK to not set a default parent since such users will
    // explicitly add this WebContentsViewAura to their tree after they create
    // us.
    if (root_window) {
      window_->SetDefaultParentByRootWindow(
          root_window, root_window->GetBoundsInScreen());
    }
  }
  window_->layer()->SetMasksToBounds(true);
  window_->SetName("WebContentsViewAura");

  window_observer_.reset(new WindowObserver(this));
#if defined(OS_WIN)
  child_window_observer_.reset(new ChildWindowObserver(this));
#endif

  // delegate_->GetDragDestDelegate() creates a new delegate on every call.
  // Hence, we save a reference to it locally. Similar model is used on other
  // platforms as well.
  if (delegate_.get())
    drag_dest_delegate_ = delegate_->GetDragDestDelegate();
}

RenderWidgetHostView* WebContentsViewAura::CreateViewForWidget(
    RenderWidgetHost* render_widget_host) {
  if (render_widget_host->GetView()) {
    // During testing, the view will already be set up in most cases to the
    // test view, so we don't want to clobber it with a real one. To verify that
    // this actually is happening (and somebody isn't accidentally creating the
    // view twice), we check for the RVH Factory, which will be set when we're
    // making special ones (which go along with the special views).
    DCHECK(RenderViewHostFactory::has_factory());
    return render_widget_host->GetView();
  }

  RenderWidgetHostView* view =
      RenderWidgetHostView::CreateViewForWidget(render_widget_host);
  view->InitAsChild(NULL);
  content_container_ = new ShadowWindow(view->GetNativeView());
  GetNativeView()->AddChild(content_container_);

  if (navigation_overlay_.get() && navigation_overlay_->has_window()) {
    navigation_overlay_->StartObservingView(static_cast<
        RenderWidgetHostViewAura*>(view));
  }

  view->Show();

  // We listen to drag drop events in the newly created view's window.
  aura::client::SetDragDropDelegate(view->GetNativeView(), this);

  RenderWidgetHostImpl* host_impl =
      RenderWidgetHostImpl::From(render_widget_host);
  if (host_impl->overscroll_controller() &&
      (!web_contents_->GetDelegate() ||
       web_contents_->GetDelegate()->CanOverscrollContent())) {
    host_impl->overscroll_controller()->set_delegate(this);
    if (!navigation_overlay_.get())
      navigation_overlay_.reset(new OverscrollNavigationOverlay());
  }

  return view;
}

RenderWidgetHostView* WebContentsViewAura::CreateViewForPopupWidget(
    RenderWidgetHost* render_widget_host) {
  return RenderWidgetHostViewPort::CreateViewForWidget(render_widget_host);
}

void WebContentsViewAura::SetPageTitle(const string16& title) {
  window_->set_title(title);
}

void WebContentsViewAura::RenderViewCreated(RenderViewHost* host) {
}

void WebContentsViewAura::RenderViewSwappedIn(RenderViewHost* host) {
  if (navigation_overlay_.get() && navigation_overlay_->has_window()) {
    navigation_overlay_->StartObservingView(static_cast<
        RenderWidgetHostViewAura*>(host->GetView()));
  }
}

void WebContentsViewAura::SetOverscrollControllerEnabled(bool enabled) {
  RenderViewHostImpl* host = static_cast<RenderViewHostImpl*>(
      web_contents_->GetRenderViewHost());
  if (host) {
    host->SetOverscrollControllerEnabled(enabled);
    if (enabled)
      host->overscroll_controller()->set_delegate(this);
  }
}

////////////////////////////////////////////////////////////////////////////////
// WebContentsViewAura, RenderViewHostDelegateView implementation:

void WebContentsViewAura::ShowContextMenu(
    const ContextMenuParams& params,
    ContextMenuSourceType type) {
  if (delegate_.get())
    delegate_->ShowContextMenu(params, type);
}

void WebContentsViewAura::ShowPopupMenu(const gfx::Rect& bounds,
                                        int item_height,
                                        double item_font_size,
                                        int selected_item,
                                        const std::vector<WebMenuItem>& items,
                                        bool right_aligned,
                                        bool allow_multiple_selection) {
  // External popup menus are only used on Mac and Android.
  NOTIMPLEMENTED();
}

void WebContentsViewAura::StartDragging(
    const WebDropData& drop_data,
    WebKit::WebDragOperationsMask operations,
    const gfx::ImageSkia& image,
    const gfx::Vector2d& image_offset,
    const DragEventSourceInfo& event_info) {
  aura::RootWindow* root_window = GetNativeView()->GetRootWindow();
  if (!aura::client::GetDragDropClient(root_window))
    return;

  ui::OSExchangeData::Provider* provider = ui::OSExchangeData::CreateProvider();
  PrepareDragData(drop_data, provider);

  ui::OSExchangeData data(provider);  // takes ownership of |provider|.

  if (!image.isNull()) {
    drag_utils::SetDragImageOnDataObject(image,
        gfx::Size(image.width(), image.height()), image_offset, &data);
  }

  scoped_ptr<WebDragSourceAura> drag_source(
      new WebDragSourceAura(GetNativeView(), web_contents_));

  // We need to enable recursive tasks on the message loop so we can get
  // updates while in the system DoDragDrop loop.
  int result_op = 0;
  {
    gfx::NativeView content_native_view = GetContentNativeView();
    MessageLoop::ScopedNestableTaskAllower allow(MessageLoop::current());
    result_op = aura::client::GetDragDropClient(root_window)->StartDragAndDrop(
        data, root_window, content_native_view,
        event_info.event_location, ConvertFromWeb(operations),
        event_info.event_source);
  }

  // Bail out immediately if the contents view window is gone. Note that it is
  // not safe to access any class members after system drag-and-drop returns
  // since the class instance might be gone. The local variable |drag_source|
  // is still valid and we can check its window property that is set to NULL
  // when the contents are gone.
  if (!drag_source->window())
    return;

  EndDrag(ConvertToWeb(result_op));
  web_contents_->GetRenderViewHost()->DragSourceSystemDragEnded();
}

void WebContentsViewAura::UpdateDragCursor(WebKit::WebDragOperation operation) {
  current_drag_op_ = operation;
}

void WebContentsViewAura::GotFocus() {
  if (web_contents_->GetDelegate())
    web_contents_->GetDelegate()->WebContentsFocused(web_contents_);
}

void WebContentsViewAura::TakeFocus(bool reverse) {
  if (web_contents_->GetDelegate() &&
      !web_contents_->GetDelegate()->TakeFocus(web_contents_, reverse) &&
      delegate_.get()) {
    delegate_->TakeFocus(reverse);
  }
}

////////////////////////////////////////////////////////////////////////////////
// WebContentsViewAura, OverscrollControllerDelegate implementation:

void WebContentsViewAura::OnOverscrollUpdate(float delta_x, float delta_y) {
  if (current_overscroll_gesture_ == OVERSCROLL_NONE)
    return;

  aura::Window* target = GetWindowToAnimateForOverscroll();
  ui::ScopedLayerAnimationSettings settings(target->layer()->GetAnimator());
  settings.SetPreemptionStrategy(ui::LayerAnimator::IMMEDIATELY_SET_NEW_TARGET);
  gfx::Vector2d translate = GetTranslationForOverscroll(delta_x, delta_y);
  gfx::Transform transform;
  transform.Translate(translate.x(), translate.y());
  target->SetTransform(transform);

  UpdateOverscrollWindowBrightness(delta_x);
}

void WebContentsViewAura::OnOverscrollComplete(OverscrollMode mode) {
  UMA_HISTOGRAM_ENUMERATION("Overscroll.Completed", mode, OVERSCROLL_COUNT);

  NavigationControllerImpl& controller = web_contents_->GetController();
  if (ShouldNavigateForward(controller, mode) ||
      ShouldNavigateBack(controller, mode)) {
    CompleteOverscrollNavigation(mode);
    return;
  }

  ResetOverscrollTransform();
}

void WebContentsViewAura::OnOverscrollModeChange(OverscrollMode old_mode,
                                                 OverscrollMode new_mode) {
  // Reset any in-progress overscroll animation first.
  ResetOverscrollTransform();

  // Make sure the content window has been prepared correctly before allowing
  // overscroll.
  bool content_window_ready =
      content_container_ &&
      GetContentNativeView() &&
      GetContentNativeView()->parent() == content_container_;

  if (new_mode == OVERSCROLL_NONE ||
      !content_window_ready ||
      (navigation_overlay_.get() && navigation_overlay_->has_window())) {
    current_overscroll_gesture_ = OVERSCROLL_NONE;
  } else {
    // Cleanup state of the content window first, because that can reset the
    // value of |current_overscroll_gesture_|.
    PrepareContentWindowForOverscroll();

    current_overscroll_gesture_ = new_mode;
    PrepareOverscrollWindow();

    UMA_HISTOGRAM_ENUMERATION("Overscroll.Started", new_mode, OVERSCROLL_COUNT);
  }
  completed_overscroll_gesture_ = OVERSCROLL_NONE;
}

////////////////////////////////////////////////////////////////////////////////
// WebContentsViewAura, ui::ImplicitAnimationObserver implementation:

void WebContentsViewAura::OnImplicitAnimationsCompleted() {
  if (ShouldNavigateForward(web_contents_->GetController(),
                            completed_overscroll_gesture_)) {
    PrepareOverscrollNavigationOverlay();
    web_contents_->GetController().GoForward();
  } else if (ShouldNavigateBack(web_contents_->GetController(),
                                completed_overscroll_gesture_)) {
    PrepareOverscrollNavigationOverlay();
    web_contents_->GetController().GoBack();
  }

  if (GetContentNativeView()) {
    content_container_->SetTransform(gfx::Transform());
    content_container_->layer()->SetLayerBrightness(0.f);
    content_container_->SetShadowEdge(SHADOW_NONE);
  }
  current_overscroll_gesture_ = OVERSCROLL_NONE;
  completed_overscroll_gesture_ = OVERSCROLL_NONE;
  overscroll_window_.reset();
}

////////////////////////////////////////////////////////////////////////////////
// WebContentsViewAura, aura::WindowDelegate implementation:

gfx::Size WebContentsViewAura::GetMinimumSize() const {
  return gfx::Size();
}

gfx::Size WebContentsViewAura::GetMaximumSize() const {
  return gfx::Size();
}

void WebContentsViewAura::OnBoundsChanged(const gfx::Rect& old_bounds,
                                          const gfx::Rect& new_bounds) {
  SizeChangedCommon(new_bounds.size());
  if (delegate_.get())
    delegate_->SizeChanged(new_bounds.size());

  // Constrained web dialogs, need to be kept centered over our content area.
  for (size_t i = 0; i < window_->children().size(); i++) {
    if (window_->children()[i]->GetProperty(
            aura::client::kConstrainedWindowKey)) {
      gfx::Rect bounds = window_->children()[i]->bounds();
      bounds.set_origin(
          gfx::Point((new_bounds.width() - bounds.width()) / 2,
                     (new_bounds.height() - bounds.height()) / 2));
      window_->children()[i]->SetBounds(bounds);
    }
  }
}

gfx::NativeCursor WebContentsViewAura::GetCursor(const gfx::Point& point) {
  return gfx::kNullCursor;
}

int WebContentsViewAura::GetNonClientComponent(const gfx::Point& point) const {
  return HTCLIENT;
}

bool WebContentsViewAura::ShouldDescendIntoChildForEventHandling(
    aura::Window* child,
    const gfx::Point& location) {
  return true;
}

bool WebContentsViewAura::CanFocus() {
  // Do not take the focus if the render widget host view is gone because
  // neither the view window nor this window can handle key events.
  return web_contents_->GetRenderWidgetHostView() != NULL;
}

void WebContentsViewAura::OnCaptureLost() {
}

void WebContentsViewAura::OnPaint(gfx::Canvas* canvas) {
}

void WebContentsViewAura::OnDeviceScaleFactorChanged(
    float device_scale_factor) {
}

void WebContentsViewAura::OnWindowDestroying() {
  // This means the destructor is going to be called soon. If there is an
  // overscroll gesture in progress (i.e. |overscroll_window_| is not NULL),
  // then destroying it in the WebContentsViewAura destructor can trigger other
  // virtual functions to be called (e.g. OnImplicitAnimationsCompleted()). So
  // destroy the overscroll window here.
  navigation_overlay_.reset();
  overscroll_window_.reset();
}

void WebContentsViewAura::OnWindowDestroyed() {
}

void WebContentsViewAura::OnWindowTargetVisibilityChanged(bool visible) {
  if (visible)
    web_contents_->WasShown();
  else
    web_contents_->WasHidden();
}

bool WebContentsViewAura::HasHitTestMask() const {
  return false;
}

void WebContentsViewAura::GetHitTestMask(gfx::Path* mask) const {
}

scoped_refptr<ui::Texture> WebContentsViewAura::CopyTexture() {
  // The layer we create doesn't have an external texture, so this should never
  // get invoked.
  NOTREACHED();
  return scoped_refptr<ui::Texture>();
}

////////////////////////////////////////////////////////////////////////////////
// WebContentsViewAura, ui::EventHandler implementation:

void WebContentsViewAura::OnKeyEvent(ui::KeyEvent* event) {
}

void WebContentsViewAura::OnMouseEvent(ui::MouseEvent* event) {
  if (!web_contents_->GetDelegate())
    return;

  switch (event->type()) {
    case ui::ET_MOUSE_PRESSED:
      web_contents_->GetDelegate()->ActivateContents(web_contents_);
      break;
    case ui::ET_MOUSE_MOVED:
      web_contents_->GetDelegate()->ContentsMouseEvent(
          web_contents_,
          gfx::Screen::GetScreenFor(GetNativeView())->GetCursorScreenPoint(),
          true);
      break;
    default:
      break;
  }
}

////////////////////////////////////////////////////////////////////////////////
// WebContentsViewAura, aura::client::DragDropDelegate implementation:

void WebContentsViewAura::OnDragEntered(const ui::DropTargetEvent& event) {
  if (drag_dest_delegate_)
    drag_dest_delegate_->DragInitialize(web_contents_);

  current_drop_data_.reset(new WebDropData());

  PrepareWebDropData(current_drop_data_.get(), event.data());
  WebKit::WebDragOperationsMask op = ConvertToWeb(event.source_operations());

  gfx::Point screen_pt =
      gfx::Screen::GetScreenFor(GetNativeView())->GetCursorScreenPoint();
  current_rvh_for_drag_ = web_contents_->GetRenderViewHost();
  web_contents_->GetRenderViewHost()->DragTargetDragEnter(
      *current_drop_data_.get(), event.location(), screen_pt, op,
      ConvertAuraEventFlagsToWebInputEventModifiers(event.flags()));

  if (drag_dest_delegate_) {
    drag_dest_delegate_->OnReceiveDragData(event.data());
    drag_dest_delegate_->OnDragEnter();
  }
}

int WebContentsViewAura::OnDragUpdated(const ui::DropTargetEvent& event) {
  DCHECK(current_rvh_for_drag_);
  if (current_rvh_for_drag_ != web_contents_->GetRenderViewHost())
    OnDragEntered(event);

  WebKit::WebDragOperationsMask op = ConvertToWeb(event.source_operations());
  gfx::Point screen_pt =
      gfx::Screen::GetScreenFor(GetNativeView())->GetCursorScreenPoint();
  web_contents_->GetRenderViewHost()->DragTargetDragOver(
      event.location(), screen_pt, op,
      ConvertAuraEventFlagsToWebInputEventModifiers(event.flags()));

  if (drag_dest_delegate_)
    drag_dest_delegate_->OnDragOver();

  return ConvertFromWeb(current_drag_op_);
}

void WebContentsViewAura::OnDragExited() {
  DCHECK(current_rvh_for_drag_);
  if (current_rvh_for_drag_ != web_contents_->GetRenderViewHost())
    return;

  web_contents_->GetRenderViewHost()->DragTargetDragLeave();
  if (drag_dest_delegate_)
    drag_dest_delegate_->OnDragLeave();

  current_drop_data_.reset();
}

int WebContentsViewAura::OnPerformDrop(const ui::DropTargetEvent& event) {
  DCHECK(current_rvh_for_drag_);
  if (current_rvh_for_drag_ != web_contents_->GetRenderViewHost())
    OnDragEntered(event);

  web_contents_->GetRenderViewHost()->DragTargetDrop(
      event.location(),
      gfx::Screen::GetScreenFor(GetNativeView())->GetCursorScreenPoint(),
      ConvertAuraEventFlagsToWebInputEventModifiers(event.flags()));
  if (drag_dest_delegate_)
    drag_dest_delegate_->OnDrop();
  current_drop_data_.reset();
  return current_drag_op_;
}

}  // namespace content