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 * The Original Code is mozilla.org code.
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#include "nsISupports.idl"
#include "nsIEventSink.idl"

/* THIS IS A PUBLIC EMBEDDING API */


/**
 * The nsIDragHelperService is a service that wraps the dispatch
 * of drag events into gecko with the appropriate management of
 * the nsDragService/nsDragSession. It frees the application from
 * having to manage details specific to how Gecko processes drag
 * and drop.
 *
 * If the browser takes up the entire window, this is straightforward:
 * call |enter| when the mouse enters the window, |tracking| while the
 * mouse moves/hovers inside the window, and |leave| when the mouse
 * exits the window. Call |drop| when the mouse is released w/in the window.
 *
 * If the browser does not take up the entire window, call |enter|
 * when the mouse enters the rectangle bounding the browser, |tracking|
 * while it is inside, |leave| when the mouse leaves the rectangle, and
 * |drop| when the mouse is released w/in the rectangle. Note that the
 * application is responsible for knowing where in its window the browser
 * has been placed.
 *
 * @status UNDER_REVIEW
 */

native DragReference(DragReference);


[uuid(22ac1757-14c5-45ef-841e-ca6e932b989c)]
interface nsIDragHelperService : nsISupports
{
  /**
   * Call when the mouse has entered the rectangle bounding the browser
   * during a drag.
   *
   * @param inDragRef the native DragReference
   * @param inSink the event sink to which the event will be dispatched
   */   
  void enter ( in DragReference inDragRef, in nsIEventSink inSink ) ;
  
  /**
   * Call when the mouse is inside the rectangle bounding the browser
   * during a drag. The return value indicates if Gecko would accept the
   * contents of the drag if a drop were to happen with the mouse in the
   * current position. This can be used for doing some rudimentary drop
   * feedback.
   *
   * @param inDragRef the native DragReference
   * @param inSink the event sink to which the event will be dispatched
   *
   * @result <code>PR_TRUE</code> if the drag would be accepted by Gecko.
   *
   */   
  boolean tracking ( in DragReference inDragRef, in nsIEventSink inSink ) ;

  /**
   * Call when the mouse has left the rectangle bounding the browser
   * during a drag.
   *
   * @param inDragRef the native DragReference
   * @param inSink the event sink to which the event will be dispatched
   */   
  void leave ( in DragReference inDragRef, in nsIEventSink inSink ) ;

  /**
   * Call when a drop occurs inside the rectangle bounding the browser.
   *
   * @param inDragRef the native DragReference
   * @param inSink the event sink to which the event will be dispatched
   *
   * @result <code>PR_TRUE</code> if the drag was accepted by Gecko.
   */   
  boolean drop ( in DragReference inDragRef, in nsIEventSink inSink ) ;

};