components/web_modal/modal_dialog_host.h

// Copyright 2013 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_WEB_MODAL_MODAL_DIALOG_HOST_H_
#define COMPONENTS_WEB_MODAL_MODAL_DIALOG_HOST_H_

#include "components/web_modal/web_modal_export.h"
#include "ui/gfx/native_widget_types.h"

namespace gfx {
class Point;
class Size;
}  // namespace gfx

namespace web_modal {

// Observer to be implemented to update modal dialogs when the host indicates
// their position needs to be changed.
class WEB_MODAL_EXPORT ModalDialogHostObserver {
 public:
  virtual ~ModalDialogHostObserver();

  virtual void OnPositionRequiresUpdate() = 0;

  // The host must call this method on each observer before destruction.
  virtual void OnHostDestroying() = 0;
};

// Interface for supporting positioning of modal dialogs over a window/widget.
class WEB_MODAL_EXPORT ModalDialogHost {
 public:
  virtual ~ModalDialogHost();

  // Returns the view against which the dialog is positioned and parented.
  virtual gfx::NativeView GetHostView() const = 0;
  // Gets the position for the dialog in coordinates relative to the host view.
  virtual gfx::Point GetDialogPosition(const gfx::Size& size) = 0;
  // Returns whether a dialog currently about to be shown should be activated.
  virtual bool ShouldActivateDialog() const;

  // Add/remove observer. The host must implement these methods, store the
  // observers in a list, and call OnHostDestroying() on each before host
  // destruction. See https://crbug.com/1170577
  virtual void AddObserver(ModalDialogHostObserver* observer) = 0;
  virtual void RemoveObserver(ModalDialogHostObserver* observer) = 0;
};

}  // namespace web_modal

#endif  // COMPONENTS_WEB_MODAL_MODAL_DIALOG_HOST_H_