DragPanelAdapter.java

/*
 * Author:  Chris Seguin
 *
 * This software has been developed under the copyleft
 * rules of the GNU General Public License.  Please
 * consult the GNU General Public License for more
 * details about use and distribution of this software.
 */
package org.acm.seguin.uml.line;

import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;

import org.acm.seguin.uml.UMLPackage;

/**
 *  This adapter handles dragging panels around on another panel. This is used
 *  to relocate the class images on the class diagram.
 *
 *@author     Chris Seguin
 *@created    July 28, 1999
 */
public class DragPanelAdapter implements MouseListener, MouseMotionListener {
	private EndPointPanel panel;
	private LinedPanel parent;
	private Point mouseStart;
	private Point panelStart;


	/**
	 *  Constructor for the DragPanelAdapter object
	 *
	 *@param  initPanel   Description of Parameter
	 *@param  initParent  Description of Parameter
	 */
	public DragPanelAdapter(EndPointPanel initPanel, LinedPanel initParent) {
		panel = initPanel;
		parent = initParent;
	}


	/**
	 *  Process a mouse click action
	 *
	 *@param  mevt  the mouse event
	 */
	public void mouseClicked(MouseEvent mevt) {
		boolean newState = !panel.isSelected();
		if ((mevt.getModifiers() & MouseEvent.BUTTON1_MASK) == 0) {
			return;
		}
		else if (!mevt.isControlDown()) {
			parent.deselectAll();
		}

		panel.setSelected(newState);
	}


	/**
	 *  Process the mouse entering the component
	 *
	 *@param  mevt  the mouse event
	 */
	public void mouseEntered(MouseEvent mevt) {
	}


	/**
	 *  Process the mouse leaving the component
	 *
	 *@param  mevt  the mouse event
	 */
	public void mouseExited(MouseEvent mevt) {
	}


	/**
	 *  Process a mouse button press
	 *
	 *@param  mevt  the mouse event
	 */
	public void mousePressed(MouseEvent mevt) {
		mouseStart = mevt.getPoint();
		panelStart = panel.getLocation(panelStart);
	}


	/**
	 *  User released the mouse button
	 *
	 *@param  mevt  the mouse event
	 */
	public void mouseReleased(MouseEvent mevt) {
		if ((mevt.getModifiers() & MouseEvent.BUTTON1_MASK) != 0) {
			if (parent instanceof LinedPanel) {
				((LinedPanel) parent).drop();
			}
			if (parent instanceof UMLPackage) {
				((UMLPackage) parent).setDirty();
			}
		}
	}


	/**
	 *  Notifies this object that it is being dragged
	 *
	 *@param  mevt  The mouse object
	 */
	public void mouseDragged(MouseEvent mevt) {
		if ((mevt.getModifiers() & MouseEvent.BUTTON1_MASK) != 0) {
			Point currentMouse = mevt.getPoint();

			int deltaX = currentMouse.x - mouseStart.x;
			int deltaY = currentMouse.y - mouseStart.y;

			if (!panel.isSelected()) {
				panel.shift(deltaX, deltaY);
			}
			else {
				parent.shift(deltaX, deltaY);
			}

			parent.repaint();
		}
	}


	/**
	 *  What to do when the mouse moves. Nothing.
	 *
	 *@param  mevt  the mouse event
	 */
	public void mouseMoved(MouseEvent mevt) {
	}
}