AggregateDragControl.java

package com.netifera.platform.ui.graphs;

import java.awt.Cursor;
import java.awt.event.MouseEvent;
import java.awt.geom.Point2D;
import java.util.Iterator;

import javax.swing.SwingUtilities;

import prefuse.Display;
import prefuse.controls.ControlAdapter;
import prefuse.visual.AggregateItem;
import prefuse.visual.VisualItem;

/**
 * Interactive drag control that is "aggregate-aware"
 */
class AggregateDragControl extends ControlAdapter {

	private VisualItem activeItem;
	protected Point2D down = new Point2D.Double();
	protected Point2D temp = new Point2D.Double();
	protected boolean dragged;

	/**
	 * Creates a new drag control that issues repaint requests as an item is
	 * dragged.
	 */
	public AggregateDragControl() {
	}

	/**
	 * @see prefuse.controls.Control#itemEntered(prefuse.visual.VisualItem,
	 *      java.awt.event.MouseEvent)
	 */
	public void itemEntered(VisualItem item, MouseEvent e) {
		Display d = (Display) e.getSource();
		d.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
		activeItem = item;
		if (!(item instanceof AggregateItem))
			setFixed(item, true);
	}

	/**
	 * @see prefuse.controls.Control#itemExited(prefuse.visual.VisualItem,
	 *      java.awt.event.MouseEvent)
	 */
	public void itemExited(VisualItem item, MouseEvent e) {
		if (activeItem == item) {
			activeItem = null;
			setFixed(item, false);
		}
		Display d = (Display) e.getSource();
		d.setCursor(Cursor.getDefaultCursor());
	}

	/**
	 * @see prefuse.controls.Control#itemPressed(prefuse.visual.VisualItem,
	 *      java.awt.event.MouseEvent)
	 */
	public void itemPressed(VisualItem item, MouseEvent e) {
		if (!SwingUtilities.isLeftMouseButton(e))
			return;
		dragged = false;
		Display d = (Display) e.getComponent();
		d.getAbsoluteCoordinate(e.getPoint(), down);
		if (item instanceof AggregateItem)
			setFixed(item, true);
	}

	/**
	 * @see prefuse.controls.Control#itemReleased(prefuse.visual.VisualItem,
	 *      java.awt.event.MouseEvent)
	 */
	public void itemReleased(VisualItem item, MouseEvent e) {
		if (!SwingUtilities.isLeftMouseButton(e))
			return;
		if (dragged) {
			activeItem = null;
			setFixed(item, false);
			dragged = false;
		}
	}

	/**
	 * @see prefuse.controls.Control#itemDragged(prefuse.visual.VisualItem,
	 *      java.awt.event.MouseEvent)
	 */
	public void itemDragged(VisualItem item, MouseEvent e) {
		if (!SwingUtilities.isLeftMouseButton(e))
			return;
		dragged = true;
		Display d = (Display) e.getComponent();
		d.getAbsoluteCoordinate(e.getPoint(), temp);
		double dx = temp.getX() - down.getX();
		double dy = temp.getY() - down.getY();

		move(item, dx, dy);

		down.setLocation(temp);
	}

	protected/* static */void setFixed(VisualItem item, boolean fixed) {
		if (item instanceof AggregateItem) {
			Iterator<?> items = ((AggregateItem) item).items();
			while (items.hasNext()) {
				setFixed((VisualItem) items.next(), fixed);
			}
		} else {
			item.setFixed(fixed);
		}
	}

	protected/* static */void move(VisualItem item, double dx, double dy) {
		if (item instanceof AggregateItem) {
			Iterator<?> items = ((AggregateItem) item).items();
			while (items.hasNext()) {
				move((VisualItem) items.next(), dx, dy);
			}
		} else {
			double x = item.getX();
			double y = item.getY();
			item.setStartX(x);
			item.setStartY(y);
			item.setX(x + dx);
			item.setY(y + dy);
			item.setEndX(x + dx);
			item.setEndY(y + dy);
		}
	}
}