gecko-dev/layout/base/nsIReflowCallback.h

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 * The Original Code is Mozilla Communicator client code.
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 * Contributor(s):
 *   Original Author: David Hyatt (hyatt@netscape.com)
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#ifndef nsIReflowCallback_h___
#define nsIReflowCallback_h___

/**
 * Reflow callback interface.
 * These are not refcounted. Objects must be removed from the presshell
 * callback list before they die.
 * Protocol: objects will either get a ReflowFinished() call when a reflow
 * has finished or a ReflowCallbackCanceled() call if the shell is destroyed,
 * whichever happens first. If the object is explicitly removed from the shell
 * (using nsIPresShell::CancelReflowCallback()) before that occurs then neither
 * of the callback methods are called.
 */
class nsIReflowCallback {
public:
  /**
   * The presshell calls this when reflow has finished. Return true if
   * you need a Flush_Layout to happen after this.
   */
  virtual bool ReflowFinished() = 0;
  /**
   * The presshell calls this on outstanding callback requests in its
   * Destroy() method. The shell removes the request after calling
   * ReflowCallbackCanceled().
   */
  virtual void ReflowCallbackCanceled() = 0;
};

#endif /* nsIReflowCallback_h___ */