chrome/browser/renderer_host/render_widget_host_view.h

// Copyright (c) 2006-2008 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.

#ifndef CHROME_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_H_
#define CHROME_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_H_

#include "base/gfx/native_widget_types.h"
#include "base/shared_memory.h"
#include "third_party/skia/include/core/SkBitmap.h"
#include "webkit/glue/webplugin.h"
#include "webkit/glue/webwidget_delegate.h"

namespace gfx {
class Rect;
class Size;
}
namespace IPC {
class Message;
}

class BackingStore;
class RenderProcessHost;
class RenderWidgetHost;
class WebCursor;

// RenderWidgetHostView is an interface implemented by an object that acts as
// the "View" portion of a RenderWidgetHost. The RenderWidgetHost and its
// associated RenderProcessHost own the "Model" in this case which is the
// child renderer process. The View is responsible for receiving events from
// the surrounding environment and passing them to the RenderWidgetHost, and
// for actually displaying the content of the RenderWidgetHost when it
// changes.
class RenderWidgetHostView {
 public:
  virtual ~RenderWidgetHostView(){};

  // Platform-specific creator. Use this to construct new RenderWidgetHostViews
  // rather than using RenderWidgetHostViewWin & friends.
  //
  // This function must NOT size it, because the RenderView in the renderer
  // wounldn't have been created yet. The widget would set its "waiting for
  // resize ack" flag, and the ack would never come becasue no RenderView
  // received it.
  //
  // The RenderWidgetHost must already be created (because we can't know if it's
  // going to be a regular RenderWidgetHost or a RenderViewHost (a subclass).
  static RenderWidgetHostView* CreateViewForWidget(RenderWidgetHost* widget);

  // Perform all the initialization steps necessary for this object to represent
  // a popup (such as a <select> dropdown), then shows the popup at |pos|.
  virtual void InitAsPopup(RenderWidgetHostView* parent_host_view,
                           const gfx::Rect& pos) = 0;

  // Returns the associated RenderWidgetHost.
  virtual RenderWidgetHost* GetRenderWidgetHost() const = 0;

  // Notifies the View that it has become visible.
  virtual void DidBecomeSelected() = 0;

  // Notifies the View that it has been hidden.
  virtual void WasHidden() = 0;

  // Tells the View to size itself to the specified size.
  virtual void SetSize(const gfx::Size& size) = 0;

  // Retrieves the native view used to contain plugins and identify the
  // renderer in IPC messages.
  virtual gfx::NativeView GetNativeView() = 0;

  // Moves all plugin windows as described in the given list.
  virtual void MovePluginWindows(
      const std::vector<WebPluginGeometry>& plugin_window_moves) = 0;

  // Actually set/take focus to/from the associated View component.
  virtual void Focus() = 0;
  virtual void Blur() = 0;

  // Returns true if the View currently has the focus.
  virtual bool HasFocus() = 0;

  // Shows/hides the view.  These must always be called together in pairs.
  // It is not legal to call Hide() multiple times in a row.
  virtual void Show() = 0;
  virtual void Hide() = 0;

  // Retrieve the bounds of the View, in screen coordinates.
  virtual gfx::Rect GetViewBounds() const = 0;

  // Sets the cursor to the one associated with the specified cursor_type
  virtual void UpdateCursor(const WebCursor& cursor) = 0;

  // Indicates whether the page has finished loading.
  virtual void SetIsLoading(bool is_loading) = 0;

  // Enable or disable IME for the view.
  virtual void IMEUpdateStatus(int control, const gfx::Rect& caret_rect) = 0;

  // Informs the view that a portion of the widget's backing store was painted.
  // The view should ensure this gets copied to the screen.
  //
  // There are subtle performance implications here.  The RenderWidget gets sent
  // a paint ack after this returns, so if the view only ever invalidates in
  // response to this, then on Windows, where WM_PAINT has lower priority than
  // events which can cause renderer resizes/paint rect updates, e.g.
  // drag-resizing can starve painting; this function thus provides the view its
  // main chance to ensure it stays painted and not just invalidated.  On the
  // other hand, if this always blindly paints, then if we're already in the
  // midst of a paint on the callstack, we can double-paint unnecessarily.
  // (Worse, we might recursively call RenderWidgetHost::GetBackingStore().)
  // Thus implementers should generally paint as much of |rect| as possible
  // synchronously with as little overpainting as possible.
  virtual void DidPaintRect(const gfx::Rect& rect) = 0;

  // Informs the view that a portion of the widget's backing store was scrolled
  // by dx pixels horizontally and dy pixels vertically. The view should copy
  // the exposed pixels from the backing store of the render widget (which has
  // already been scrolled) onto the screen.
  virtual void DidScrollRect(
      const gfx::Rect& rect, int dx, int dy) = 0;

  // Notifies the View that the renderer has ceased to exist.
  virtual void RenderViewGone() = 0;

  // Tells the View to destroy itself.
  virtual void Destroy() = 0;

  // Tells the View that the tooltip text for the current mouse position over
  // the page has changed.
  virtual void SetTooltipText(const std::wstring& tooltip_text) = 0;

  // Notifies the View that the renderer text selection has changed.
  virtual void SelectionChanged(const std::string& text) { };

  // Tells the View to get the text from the selection clipboard and send it
  // back to the renderer asynchronously.
  virtual void PasteFromSelectionClipboard() { }

  // Tells the View whether the context menu is showing. This is used on Linux
  // to suppress updates to webkit focus for the duration of the show.
  virtual void ShowingContextMenu(bool showing) { }

  // Allocate a backing store for this view
  virtual BackingStore* AllocBackingStore(const gfx::Size& size) = 0;

#if defined(OS_MACOSX)
  // Display a native control popup menu for WebKit.
  virtual void ShowPopupWithItems(gfx::Rect bounds,
                                  int item_height,
                                  int selected_item,
                                  const std::vector<WebMenuItem>& items) = 0;
#endif

  void set_activatable(bool activatable) {
    activatable_ = activatable;
  }
  bool activatable() const { return activatable_; }

  // Subclasses should override this method to do whatever is appropriate to set
  // the custom background for their platform.
  virtual void SetBackground(const SkBitmap& background) {
    background_ = background;
  }
  const SkBitmap& background() const { return background_; }

 protected:
  // Interface class only, do not construct.
  RenderWidgetHostView() : activatable_(true) {}

  // Whether the window can be activated. Autocomplete popup windows for example
  // cannot be activated.  Default is true.
  bool activatable_;

  // A custom background to paint behind the web content. This will be tiled
  // horizontally. Can be null, in which case we fall back to painting white.
  SkBitmap background_;

 private:
  DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostView);
};

#endif  // CHROME_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_H_