Method setDropLocation

unused/javax/swing/JTree.java:1430–1466

Called to set or clear the drop location during a DnD operation. In some cases, the component may need to use it's internal selection temporarily to indicate the drop location. To help facilitate this, this method returns and accepts as a parameter a state object. This state object can be used to st

(TransferHandler.DropLocation location,
                           Object state,
                           boolean forDrop)

     * @return any saved state for this component, or <code>null</code> if none
     */
    Object setDropLocation(TransferHandler.DropLocation location,
                           Object state,
                           boolean forDrop) {

        Object retVal = null;
        DropLocation treeLocation = (DropLocation)location;

        if (dropMode == DropMode.USE_SELECTION) {
            if (treeLocation == null) {
                if (!forDrop && state != null) {
                    setSelectionPaths(((TreePath[][])state)[0]);
                    setAnchorSelectionPath(((TreePath[][])state)[1][0]);
                    setLeadSelectionPath(((TreePath[][])state)[1][1]);
                }
            } else {
                if (dropLocation == null) {
                    TreePath[] paths = getSelectionPaths();
                    if (paths == null) {
                        paths = new TreePath[0];
                    }

                    retVal = new TreePath[][] {paths,
                            {getAnchorSelectionPath(), getLeadSelectionPath()}};
                } else {
                    retVal = state;
                }

                setSelectionPath(treeLocation.getPath());
            }
        }

        DropLocation old = dropLocation;
        dropLocation = treeLocation;
        firePropertyChange("dropLocation", old, dropLocation);

        return retVal;
    }

    /**
     * Called to indicate to this component that DnD is done.