michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "nsISupports.idl"
michael@0: 
michael@0: /**
michael@0:  * This interface exposes the general notion of a scheduled object with a
michael@0:  * integral priority value.  Following UNIX conventions, smaller (and possibly
michael@0:  * negative) values have higher priority.
michael@0:  *
michael@0:  * This interface does not strictly define what happens when the priority of an
michael@0:  * object is changed.  An implementation of this interface is free to define
michael@0:  * the side-effects of changing the priority of an object.  In some cases,
michael@0:  * changing the priority of an object may be disallowed (resulting in an
michael@0:  * exception being thrown) or may simply be ignored.
michael@0:  */
michael@0: [scriptable, uuid(aa578b44-abd5-4c19-8b14-36d4de6fdc36)]
michael@0: interface nsISupportsPriority : nsISupports
michael@0: {
michael@0:   /**
michael@0:    * Typical priority values.
michael@0:    */
michael@0:   const long PRIORITY_HIGHEST = -20;
michael@0:   const long PRIORITY_HIGH    = -10;
michael@0:   const long PRIORITY_NORMAL  =   0;
michael@0:   const long PRIORITY_LOW     =  10;
michael@0:   const long PRIORITY_LOWEST  =  20;
michael@0:   
michael@0:   /**
michael@0:    * This attribute may be modified to change the priority of this object.  The
michael@0:    * implementation of this interface is free to truncate a given priority
michael@0:    * value to whatever limits are appropriate.  Typically, this attribute is
michael@0:    * initialized to PRIORITY_NORMAL, but implementations may choose to assign a
michael@0:    * different initial value.
michael@0:    */
michael@0:   attribute long priority;
michael@0: 
michael@0:   /**
michael@0:    * This method adjusts the priority attribute by a given delta.  It helps
michael@0:    * reduce the amount of coding required to increment or decrement the value
michael@0:    * of the priority attribute.
michael@0:    */
michael@0:   void adjustPriority(in long delta);
michael@0: };