/* 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.
 */

/**
 * This file defines the <code>PPB_Buffer_Dev</code> interface.
 */
label Chrome {
  M14 = 0.5
};

[assert_size(4)]
enum PP_ScrollBy_Dev {
  PP_SCROLLBY_PIXEL = 0,
  PP_SCROLLBY_LINE = 1,
  PP_SCROLLBY_PAGE = 2,
  PP_SCROLLBY_DOCUMENT = 3
};

/**
 * The interface for a scrollbar.  A scrollbar is a widget, so the functions
 * in PPB_Widget can also be used with scrollbar objects.
 */
interface PPB_Scrollbar_Dev {
  /**
   * Create a new scrollbar.  Returns 0 if the instance is invalid.
   */
  PP_Resource Create([in] PP_Instance instance,
                     [in] PP_Bool vertical);

  /**
   * Returns PP_TRUE if the given resource is a Scrollbar. Returns PP_FALSE if
   * the resource is invalid or some type other than a scrollbar.
   */
  PP_Bool IsScrollbar([in] PP_Resource resource);

  /**
   * Gets the thickness of a scrollbar.
   */
  uint32_t GetThickness([in] PP_Resource resource);

  /**
   * Returns PP_TRUE if the system scrollbar style is an overlap scrollbar.
   */
  PP_Bool IsOverlay([in] PP_Resource scrollbar);

  /**
   * Gets the value of the scrollbar.
   */
  uint32_t GetValue([in] PP_Resource scrollbar);

  /**
   * Sets the value of the scrollbar.
   */
  void SetValue([in] PP_Resource scrollbar,
                [in] uint32_t value);

  /**
   * Set the document size (i.e. total length of the region that's being
   * scrolled).
   */
  void SetDocumentSize([in] PP_Resource scrollbar,
                       [in] uint32_t size);

  /**
   * Updates the tickmarks.  Only valid for vertical scrollbars.  "tick_marks"
   * contains "count" PP_Rect objects.
   */
  void SetTickMarks([in] PP_Resource scrollbar,
                    [in, size_as=count] PP_Rect[] tick_marks,
                    [in] uint32_t count);

  /**
   * Scroll by "multiplier" pixels/lines/pages units.  Positive values are
   * forward and negative are backward.  If "unit" is document then any positive
   * value goes to the end while any negative value goes to the beginning.
   */
  void ScrollBy([in] PP_Resource scrollbar,
                [in] PP_ScrollBy_Dev unit,
                [in] int32_t multiplier);
};