layout/base/nsIReflowCallback.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6 #ifndef nsIReflowCallback_h___
   7 #define nsIReflowCallback_h___
   8
   9 /**
  10  * Reflow callback interface.
  11  * These are not refcounted. Objects must be removed from the presshell
  12  * callback list before they die.
  13  * Protocol: objects will either get a ReflowFinished() call when a reflow
  14  * has finished or a ReflowCallbackCanceled() call if the shell is destroyed,
  15  * whichever happens first. If the object is explicitly removed from the shell
  16  * (using PresShell::CancelReflowCallback()) before that occurs then neither
  17  * of the callback methods are called.
  18  */
  19 class nsIReflowCallback {
  20  public:
  21   /**
  22    * The presshell calls this when reflow has finished. Return true if
  23    * you need a FlushType::Layout to happen after this.
  24    */
  25   virtual bool ReflowFinished() = 0;
  26   /**
  27    * The presshell calls this on outstanding callback requests in its
  28    * Destroy() method. The shell removes the request after calling
  29    * ReflowCallbackCanceled().
  30    */
  31   virtual void ReflowCallbackCanceled() = 0;
  32 };
  33
  34 #endif /* nsIReflowCallback_h___ */