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/* 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.
*/
/* From ppb_view.idl modified Fri Feb 17 09:09:15 2012. */
#ifndef PPAPI_C_PPB_VIEW_H_
#define PPAPI_C_PPB_VIEW_H_
#include "ppapi/c/pp_bool.h"
#include "ppapi/c/pp_macros.h"
#include "ppapi/c/pp_point.h"
#include "ppapi/c/pp_rect.h"
#include "ppapi/c/pp_resource.h"
#include "ppapi/c/pp_size.h"
#include "ppapi/c/pp_stdint.h"
#define PPB_VIEW_INTERFACE_1_0 "PPB_View;1.0"
#define PPB_VIEW_INTERFACE PPB_VIEW_INTERFACE_1_0
/**
* @file
* This file defines the <code>PPB_View</code> struct representing the state
* of the view of an instance.
*/
/**
* @addtogroup Interfaces
* @{
*/
/**
* <code>PPB_View</code> represents the state of the view of an instance.
* You will receive new view information using
* <code>PPP_Instance.DidChangeView</code>.
*/
struct PPB_View_1_0 {
/**
* IsView() determines if the given resource is a valid
* <code>PPB_View</code> resource. Note that <code>PPB_ViewChanged</code>
* resources derive from <code>PPB_View</code> and will return true here
* as well.
*
* @param resource A <code>PP_Resource</code> corresponding to a
* <code>PPB_View</code> resource.
*
* @return <code>PP_TRUE</code> if the given resource supports
* <code>PPB_View</code> or <code>PP_FALSE</code> if it is an invalid
* resource or is a resource of another type.
*/
PP_Bool (*IsView)(PP_Resource resource);
/**
* GetRect() retrieves the rectangle of the module instance associated
* with a view changed notification relative to the upper-left of the browser
* viewport. This position changes when the page is scrolled.
*
* The returned rectangle may not be inside the visible portion of the
* viewport if the module instance is scrolled off the page. Therefore, the
* position may be negative or larger than the size of the page. The size will
* always reflect the size of the module were it to be scrolled entirely into
* view.
*
* In general, most modules will not need to worry about the position of the
* module instance in the viewport, and only need to use the size.
*
* @param resource A <code>PP_Resource</code> corresponding to a
* <code>PPB_View</code> resource.
*
* @param rect A <code>PP_Rect</code> receiving the rectangle on success.
*
* @return Returns <code>PP_TRUE</code> if the resource was valid and the
* viewport rectangle was filled in, <code>PP_FALSE</code> if not.
*/
PP_Bool (*GetRect)(PP_Resource resource, struct PP_Rect* rect);
/**
* IsFullscreen() returns whether the instance is currently
* displaying in fullscreen mode.
*
* @param resource A <code>PP_Resource</code> corresponding to a
* <code>PPB_View</code> resource.
*
* @return <code>PP_TRUE</code> if the instance is in full screen mode,
* or <code>PP_FALSE</code> if it's not or the resource is invalid.
*/
PP_Bool (*IsFullscreen)(PP_Resource resource);
/**
* IsVisible() determines whether the module instance might be visible to
* the user. For example, the Chrome window could be minimized or another
* window could be over it. In both of these cases, the module instance
* would not be visible to the user, but IsVisible() will return true.
*
* Use the result to speed up or stop updates for invisible module
* instances.
*
* This function performs the duties of GetRect() (determining whether the
* module instance is scrolled into view and the clip rectangle is nonempty)
* and IsPageVisible() (whether the page is visible to the user).
*
* @param resource A <code>PP_Resource</code> corresponding to a
* <code>PPB_View</code> resource.
*
* @return <code>PP_TRUE</code> if the instance might be visible to the
* user, <code>PP_FALSE</code> if it is definitely not visible.
*/
PP_Bool (*IsVisible)(PP_Resource resource);
/**
* IsPageVisible() determines if the page that contains the module instance
* is visible. The most common cause of invisible pages is that
* the page is in a background tab in the browser.
*
* Most applications should use IsVisible() instead of this function since
* the module instance could be scrolled off of a visible page, and this
* function will still return true. However, depending on how your module
* interacts with the page, there may be certain updates that you may want to
* perform when the page is visible even if your specific module instance is
* not visible.
*
* @param resource A <code>PP_Resource</code> corresponding to a
* <code>PPB_View</code> resource.
*
* @return <code>PP_TRUE</code> if the instance is plausibly visible to the
* user, <code>PP_FALSE</code> if it is definitely not visible.
*/
PP_Bool (*IsPageVisible)(PP_Resource resource);
/**
* GetClipRect() returns the clip rectangle relative to the upper-left corner
* of the module instance. This rectangle indicates the portions of the module
* instance that are scrolled into view.
*
* If the module instance is scrolled off the view, the return value will be
* (0, 0, 0, 0). This clip rectangle does <i>not</i> take into account page
* visibility. Therefore, if the module instance is scrolled into view, but
* the page itself is on a tab that is not visible, the return rectangle will
* contain the visible rectangle as though the page were visible. Refer to
* IsPageVisible() and IsVisible() if you want to account for page
* visibility.
*
* Most applications will not need to worry about the clip rectangle. The
* recommended behavior is to do full updates if the module instance is
* visible, as determined by IsVisible(), and do no updates if it is not
* visible.
*
* However, if the cost for computing pixels is very high for your
* application, or the pages you're targeting frequently have very large
* module instances with small visible portions, you may wish to optimize
* further. In this case, the clip rectangle will tell you which parts of
* the module to update.
*
* Note that painting of the page and sending of view changed updates
* happens asynchronously. This means when the user scrolls, for example,
* it is likely that the previous backing store of the module instance will
* be used for the first paint, and will be updated later when your
* application generates new content with the new clip. This may cause
* flickering at the boundaries when scrolling. If you do choose to do
* partial updates, you may want to think about what color the invisible
* portions of your backing store contain (be it transparent or some
* background color) or to paint a certain region outside the clip to reduce
* the visual distraction when this happens.
*
* @param resource A <code>PP_Resource</code> corresponding to a
* <code>PPB_View</code> resource.
*
* @param clip Output argument receiving the clip rect on success.
*
* @return Returns <code>PP_TRUE</code> if the resource was valid and the
* clip rect was filled in, <code>PP_FALSE</code> if not.
*/
PP_Bool (*GetClipRect)(PP_Resource resource, struct PP_Rect* clip);
};
typedef struct PPB_View_1_0 PPB_View;
/**
* @}
*/
#endif /* PPAPI_C_PPB_VIEW_H_ */
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