DropTarget.java 文件源码

/**
    * Creates a new DropTarget given the <code>Component</code> 
    * to associate itself with, an <code>int</code> representing
    * the default acceptable action(s) to 
    * support, a <code>DropTargetListener</code>
    * to handle event processing, a <code>boolean</code> indicating 
    * if the <code>DropTarget</code> is currently accepting drops, and 
    * a <code>FlavorMap</code> to use (or null for the default <CODE>FlavorMap</CODE>).
    * <P>
    * The Component will receive drops only if it is enabled.
    * @param c  The <code>Component</code> with which this <code>DropTarget</code> is associated
    * @param ops    The default acceptable actions for this <code>DropTarget</code>
    * @param dtl    The <code>DropTargetListener</code> for this <code>DropTarget</code>
    * @param act    Is the <code>DropTarget</code> accepting drops.
    * @param fm The <code>FlavorMap</code> to use, or null for the default <CODE>FlavorMap</CODE> 
    * @exception HeadlessException if GraphicsEnvironment.isHeadless()
    *            returns true
    * @see java.awt.GraphicsEnvironment#isHeadless
    */
   public DropTarget(Component c, int ops, DropTargetListener dtl,
          boolean act, FlavorMap fm)
       throws HeadlessException
   {
       if (GraphicsEnvironment.isHeadless()) {
           throw new HeadlessException();
       }

component = c;

setDefaultActions(ops);

if (dtl != null) try {
    addDropTargetListener(dtl);
} catch (TooManyListenersException tmle) {
    // do nothing!
}

if (c != null) {
    c.setDropTarget(this);
    setActive(act);
}

       if (fm != null) flavorMap = fm;
   }