xpcom/threads/nsISupportsPriority.idl

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #include "nsISupports.idl"
   6
   7 /**
   8  * This interface exposes the general notion of a scheduled object with a
   9  * integral priority value.  Following UNIX conventions, smaller (and possibly
  10  * negative) values have higher priority.
  11  *
  12  * This interface does not strictly define what happens when the priority of an
  13  * object is changed.  An implementation of this interface is free to define
  14  * the side-effects of changing the priority of an object.  In some cases,
  15  * changing the priority of an object may be disallowed (resulting in an
  16  * exception being thrown) or may simply be ignored.
  17  */
  18 [scriptable, uuid(aa578b44-abd5-4c19-8b14-36d4de6fdc36)]
  19 interface nsISupportsPriority : nsISupports
  20 {
  21   /**
  22    * Typical priority values.
  23    */
  24   const long PRIORITY_HIGHEST = -20;
  25   const long PRIORITY_HIGH    = -10;
  26   const long PRIORITY_NORMAL  =   0;
  27   const long PRIORITY_LOW     =  10;
  28   const long PRIORITY_LOWEST  =  20;
  29
  30   /**
  31    * This attribute may be modified to change the priority of this object.  The
  32    * implementation of this interface is free to truncate a given priority
  33    * value to whatever limits are appropriate.  Typically, this attribute is
  34    * initialized to PRIORITY_NORMAL, but implementations may choose to assign a
  35    * different initial value.
  36    */
  37   attribute long priority;
  38
  39   /**
  40    * This method adjusts the priority attribute by a given delta.  It helps
  41    * reduce the amount of coding required to increment or decrement the value
  42    * of the priority attribute.
  43    */
  44   void adjustPriority(in long delta);
  45 };