Change the DidChangeView update to take a new ViewChanged resource.

ppapi/api/ppb_view.idl

+/* Copyright (c) 2011 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.
+ */
+
+/**
+ * Defines the <code>PPB_View</code> struct representing the state of the
+ * view of an instance.
+ */
+
+label Chrome {
+  M18 = 1.0
+};
+
+/**
+ * <code>PPB_View</code> represents the state of the view of an instance.
+ * You can get a View object with the <code>PPB_Instance.GetView()</code>

[darin (slow to review), 2012/01/31 21:56:47]

nit: there is no GetView() method

+ * function. Additionally, all </code>PPB_ViewChanged</code> objects are also

[darin (slow to review), 2012/01/31 21:56:47]

nit: PPB_ViewChanged doesn't exist in this rev of the CL

+ * <code>PPB_View</code> objects so you will receive new view information via
+ * <code>PPP_Instance.DidChangeView</code>.
+ */
+[macro="PPB_VIEW_INTERFACE"]
+interface PPB_View {
+  /**
+   * <code>IsView()</code> 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.
+   *
+   * @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([in] PP_Resource resource);
+
+  /**
+   * <code>GetRect()</code> retrieves the rectangle of the instance
+   * associated with the 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 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 plugin were it to be scrolled entirely into view.
+   *
+   * In general, most plugins will not need to worry about the position of the
+   * instance in the viewport, and only need to use the size.
+   *
+   * @param rect Output argument receiving the rectangle on success.
+   *
+   * @return Returns <code>PP_TRUE</code> if the resource was valid and the
+   * viewport rect was filled in, <code>PP_FALSE</code> if not.
+   */
+  PP_Bool GetRect([in] PP_Resource resource,
+                  [out] PP_Rect rect);
+
+  /**
+   * <code>IsFullscreen()</code> returns whether the instance is currently
+   * displaying in fullscreen mode.
+   *
+   * @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([in] PP_Resource resource);
+
+  /**
+   * <code>IsVisible()</code> returns whether the instance is plausibly
+   * visible to the user. You should use this flag to throttle or stop updates
+   * for invisible plugins.
+   *
+   * Thie measure incorporates both whether the instance is scrolled into
+   * view (whether the clip rect is nonempty) and whether the page is plausibly
+   * visible to the user (<code>IsPageVisible()</code>).
+   *
+   * @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 IsVisible([in] PP_Resource resource);
+
+  /**
+   * <code>IsPageVisible()</code> determines if the page that contains the
+   * 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 <code>IsVisible()</code> rather than
+   * this function since the instance could be scrolled off of a visible
+   * page, and this function will still return true. However, depending on
+   * how your plugin interacts with the page, there may be certain updates
+   * that you may want to perform when the page is visible even if your
+   * specific instance isn't.
+   *
+   * @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([in] PP_Resource resource);
+
+  /**
+   * <code>GetClipRect()</code> returns the clip rectangle relative to the
+   * upper left corner of the instance. This rectangle indicates which parts of
+   * the instance are scrolled into view.
+   *
+   * If the instance is scrolled off the view, the return value will be
+   * (0, 0, 0, 0). this state. This clip rect does <i>not</i> take into account
+   * page visibility. This means if the instance is scrolled into view but the
+   * page itself is in an invisible tab, the return rect will contain the
+   * visible rect assuming the page was visible. See
+   * <code>IsPageVisible()</code> and <code>IsVisible()</code> if you want to
+   * handle this case.
+   *
+   * Most applications will not need to worry about the clip. The recommended
+   * behavior is to do full updates if the instance is visible as determined by
+   * <code>IsVisible()</code> and do no updates if not.
+   *
+   * However, if the cost for computing pixels is very high for your
+   * application or the pages you're targeting frequently have very large
+   * instances with small visible portions, you may wish to optimize further.
+   * In this case, the clip rect will tell you which parts of the plugin 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 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 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([in] PP_Resource resource,
+                      [out] PP_Rect clip);
+};
+