// 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.

#ifndef UI_VIEWS_WINDOW_DIALOG_CLIENT_VIEW_H_
#define UI_VIEWS_WINDOW_DIALOG_CLIENT_VIEW_H_

#include "ui/base/ui_base_types.h"
#include "ui/views/controls/button/button.h"
#include "ui/views/focus/focus_manager.h"
#include "ui/views/window/client_view.h"

namespace views {

class DialogDelegate;
class TextButton;
class Widget;
namespace internal {
class RootView;
}

///////////////////////////////////////////////////////////////////////////////
// DialogClientView
//
//  This ClientView subclass provides the content of a typical dialog box,
//  including a strip of buttons at the bottom right of the window, default
//  accelerator handlers for accept and cancel, and the ability for the
//  embedded contents view to provide extra UI to be shown in the row of
//  buttons.
//
//  DialogClientView also provides the ability to set an arbitrary view that is
//  positioned beneath the buttons.
//
class VIEWS_EXPORT DialogClientView : public ClientView,
                                      public ButtonListener,
                                      public FocusChangeListener {
 public:
  DialogClientView(Widget* widget, View* contents_view);
  virtual ~DialogClientView();

  // Adds the dialog buttons required by the supplied DialogDelegate to the
  // view.
  void ShowDialogButtons();

  // Updates the enabled state and label of the buttons required by the
  // supplied DialogDelegate
  void UpdateDialogButtons();

  // Accept the changes made in the window that contains this ClientView.
  void AcceptWindow();

  // Cancel the changes made in the window that contains this ClientView.
  void CancelWindow();

  // Accessors in case the user wishes to adjust these buttons.
  TextButton* ok_button() const { return ok_button_; }
  TextButton* cancel_button() const { return cancel_button_; }

  // Returns the number of pixels at the bottom of the dialog which are visually
  // part of the frame, but are actually rendered by the DialogClientView.
  int GetBottomMargin();

  // Overridden from View:
  virtual void NativeViewHierarchyChanged(
      bool attached,
      gfx::NativeView native_view,
      internal::RootView* root_view) OVERRIDE;

  // Overridden from ClientView:
  virtual bool CanClose() OVERRIDE;
  virtual void WidgetClosing() OVERRIDE;
  virtual int NonClientHitTest(const gfx::Point& point) OVERRIDE;
  virtual DialogClientView* AsDialogClientView() OVERRIDE;
  virtual const DialogClientView* AsDialogClientView() const OVERRIDE;

  // FocusChangeListener implementation:
  virtual void OnWillChangeFocus(View* focused_before,
                                 View* focused_now) OVERRIDE;
  virtual void OnDidChangeFocus(View* focused_before,
                                View* focused_now) OVERRIDE;

 protected:
  // View overrides:
  virtual void PaintChildren(gfx::Canvas* canvas) OVERRIDE;
  virtual void Layout() OVERRIDE;
  virtual void ViewHierarchyChanged(bool is_add, View* parent,
                                    View* child) OVERRIDE;
  virtual gfx::Size GetPreferredSize() OVERRIDE;
  virtual bool AcceleratorPressed(const ui::Accelerator& accelerator) OVERRIDE;

  // ButtonListener implementation:
  virtual void ButtonPressed(Button* sender,
                             const ui::Event& event) OVERRIDE;

 private:
  // Parameters for the internal dialog styling.
  struct StyleParams {
    StyleParams();

    int button_vedge_margin;
    int button_hedge_margin;
    int button_shadow_margin;
    int button_content_spacing;
    int related_button_hspacing;
  };

  // Create a dialog button of the appropriate type.
  TextButton* CreateDialogButton(ui::DialogButton type, const string16& title);

  // Paint the size box in the bottom right corner of the window if it is
  // resizable.
  void PaintSizeBox(gfx::Canvas* canvas);

  // Returns the greater of ok and cancel button's preferred height.
  int GetButtonsHeight() const;

  // Returns the height of the dialog buttons area, including the spacing
  // between bottom of contents view and top of buttons, the buttons height,
  // and the spacing between bottom of buttons to end of the dialog.
  int GetDialogButtonsAreaHeight() const;

  // Returns the preferred height of |footnote_view_|, or 0 if that view is
  // NULL.
  int GetFootnoteViewHeight() const;

  // Position and size various sub-views.
  void LayoutDialogButtons();
  void LayoutContentsView();
  void LayoutFootnoteView();

  // Makes the specified button the default button.
  void SetDefaultButton(TextButton* button);

  bool has_dialog_buttons() const { return ok_button_ || cancel_button_; }

  // Create and add the extra view, if supplied by the delegate.
  void CreateExtraView();

  // Creates and adds the footnote view, if supplied by the delegate.
  void CreateFootnoteView();

  // Returns the DialogDelegate for the window.
  DialogDelegate* GetDialogDelegate() const;

  // Closes the widget.
  void Close();

  // Updates focus listener.
  void UpdateFocusListener();

  // Parameters for the internal dialog styling.
  StyleParams style_params_;

  // The dialog buttons.
  TextButton* ok_button_;
  TextButton* cancel_button_;

  // The button that is currently the default button if any.
  TextButton* default_button_;

  // The button-level extra view, NULL unless the dialog delegate supplies one.
  View* extra_view_;

  // The view that resides beneath the dialog buttons, or NULL.
  View* footnote_view_;

  // See description of DialogDelegate::GetSizeExtraViewHeightToButtons for
  // details on this.
  bool size_extra_view_height_to_buttons_;

  // The layout rect of the size box, when visible.
  gfx::Rect size_box_bounds_;

  // True if we've notified the delegate the window is closing and the delegate
  // allosed the close. In some situations it's possible to get two closes (see
  // http://crbug.com/71940). This is used to avoid notifying the delegate
  // twice, which can have bad consequences.
  bool notified_delegate_;

  // true if focus listener is added.
  bool listening_to_focus_;

  // When ancestor gets changed focus manager gets changed as well.
  FocusManager* saved_focus_manager_;

  DISALLOW_COPY_AND_ASSIGN(DialogClientView);
};

}  // namespace views

#endif  // UI_VIEWS_WINDOW_DIALOG_CLIENT_VIEW_H_