popup_controller_common.h

// Copyright 2014 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_UI_AUTOFILL_POPUP_CONTROLLER_COMMON_H_
#define CHROME_BROWSER_UI_AUTOFILL_POPUP_CONTROLLER_COMMON_H_

#include "content/public/browser/render_widget_host.h"
#include "ui/gfx/native_widget_types.h"
#include "ui/gfx/geometry/rect.h"
#include "ui/gfx/geometry/rect_f.h"

namespace content {
struct NativeWebKeyboardEvent;
class RenderViewHost;
class WebContents;
}

namespace gfx {
class Display;
}

namespace autofill {

// Class that controls common functionality for  Autofill style popups. Can
// determine the correct location of a popup of a desired size and can register
// a handler to key press events.
class PopupControllerCommon {
 public:
  PopupControllerCommon(const gfx::RectF& element_bounds,
                        gfx::NativeView container_view,
                        content::WebContents* web_contents);
  virtual ~PopupControllerCommon();

  const gfx::RectF& element_bounds() const { return element_bounds_; }
  gfx::NativeView container_view() { return container_view_; }
  content::WebContents* web_contents() { return web_contents_; }

  // Returns the enclosing rectangle for |element_bounds_|.
  const gfx::Rect RoundedElementBounds() const;

  // Returns the bounds that the popup should be placed at, given the desired
  // width and height. By default this places the popup below |element_bounds|
  // but it will be placed above if there isn't enough space.
  gfx::Rect GetPopupBounds(int desired_width, int desired_height) const;

  // Callback used to register with RenderViewHost. This can only be set once,
  // or else a callback may be registered that will not be removed
  // (crbug.com/338070). Call will crash if callback is already set.
  void SetKeyPressCallback(content::RenderWidgetHost::KeyPressEventCallback);

  // Register listener for key press events with the current RenderViewHost
  // associated with |web_contents_|. If callback has already been registered,
  // this has no effect.
  void RegisterKeyPressCallback();

  // Remove previously registered callback, assuming that the current
  // RenderViewHost is the same as when it was originally registered. Safe to
  // call even if the callback is not currently registered.
  void RemoveKeyPressCallback();

 protected:
  // A helper function to get the display closest to the given point (virtual
  // for testing).
  virtual gfx::Display GetDisplayNearestPoint(const gfx::Point& point) const;

 private:
  // Calculates the width of the popup and the x position of it. These values
  // will stay on the screen.
  std::pair<int, int> CalculatePopupXAndWidth(
      const gfx::Display& left_display,
      const gfx::Display& right_display,
      int popup_required_width) const;

  // Calculates the height of the popup and the y position of it. These values
  // will stay on the screen.
  std::pair<int, int> CalculatePopupYAndHeight(
      const gfx::Display& top_display,
      const gfx::Display& bottom_display,
      int popup_required_height) const;

  // The bounds of the text element that is the focus of the popup.
  // These coordinates are in screen space.
  gfx::RectF element_bounds_;

  // Weak reference
  gfx::NativeView container_view_;

  // The WebContents in which this object should listen for keyboard events
  // while showing the popup. Can be NULL, in which case this object will not
  // listen for keyboard events.
  content::WebContents* web_contents_;

  // The RenderViewHost that this object has registered its keyboard press
  // callback with.
  content::RenderViewHost* key_press_event_target_;

  content::RenderWidgetHost::KeyPressEventCallback key_press_event_callback_;

  DISALLOW_COPY_AND_ASSIGN(PopupControllerCommon);
};

}  // namespace autofill

#endif  // CHROME_BROWSER_UI_AUTOFILL_POPUP_CONTROLLER_COMMON_H_