chrome/renderer/page_click_tracker.h

// Copyright (c) 2011 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_RENDERER_PAGE_CLICK_TRACKER_H_
#define CHROME_RENDERER_PAGE_CLICK_TRACKER_H_

#include <vector>

#include "base/basictypes.h"
#include "base/observer_list.h"
#include "content/public/renderer/render_view_observer.h"
#include "third_party/WebKit/Source/WebKit/chromium/public/WebDOMEventListener.h"
#include "third_party/WebKit/Source/WebKit/chromium/public/WebNode.h"

class PageClickListener;


// This class is responsible for tracking clicks on elements in web pages and
// notifiying the associated listener when a node is clicked.
// Compared to a simple WebDOMEventListener, it offers the added capability of
// notifying the listeners of whether the clicked node was already focused
// before it was clicked.
//
// This is useful for password/form autofill where we want to trigger a
// suggestion popup when a text input is clicked.
// It only notifies of WebInputElement that are text inputs being clicked, but
// could easily be changed to report click on any type of WebNode.
//
// There is one PageClickTracker per RenderView.
class PageClickTracker : public content::RenderViewObserver,
                         public WebKit::WebDOMEventListener {
 public:
  explicit PageClickTracker(content::RenderView* render_view);
  virtual ~PageClickTracker();

  // Adds/removes a listener for getting notification when an element is
  // clicked.  Note that the order of insertion is important as a listener when
  // notified can decide to stop the propagation of the event (so that listeners
  // inserted after don't get the notification).
  void AddListener(PageClickListener* listener);
  void RemoveListener(PageClickListener* listener);

 private:
  // RenderView::Observer implementation.
  virtual void DidFinishDocumentLoad(WebKit::WebFrame* frame) OVERRIDE;
  virtual void FrameDetached(WebKit::WebFrame* frame) OVERRIDE;
  virtual void DidHandleMouseEvent(const WebKit::WebMouseEvent& event) OVERRIDE;

  // WebKit::WebDOMEventListener implementation.
  virtual void handleEvent(const WebKit::WebDOMEvent& event);

  // Checks to see if a text field is losing focus and inform listeners if
  // it is.
  void HandleTextFieldMaybeLosingFocus(
      const WebKit::WebNode& newly_clicked_node);

  // The last node that was clicked and had focus.
  WebKit::WebNode last_node_clicked_;

  // Whether the last clicked node had focused before it was clicked.
  bool was_focused_;

  // The frames we are listening to for mouse events.
  typedef std::vector<WebKit::WebFrame*> FrameList;
  FrameList tracked_frames_;

  // The listener getting the actual notifications.
  ObserverList<PageClickListener> listeners_;

  DISALLOW_COPY_AND_ASSIGN(PageClickTracker);
};

#endif  // CHROME_RENDERER_PAGE_CLICK_TRACKER_H_