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;
    } else {
        flavorMap = SystemFlavorMap.getDefaultFlavorMap();
    }
}