mxCellOverlay.java

package com.mxgraph.swing.util;

import java.awt.Cursor;
import java.awt.Graphics;

import javax.swing.ImageIcon;
import javax.swing.JComponent;

import com.mxgraph.util.mxConstants;
import com.mxgraph.util.mxPoint;
import com.mxgraph.util.mxRectangle;
import com.mxgraph.view.mxCellState;

public class mxCellOverlay extends JComponent implements mxICellOverlay
{

	/**
	 * 
	 */
	private static final long serialVersionUID = 921991820491141221L;

	/**
	 * 
	 */
	protected ImageIcon imageIcon;

	/**
	 * Holds the horizontal alignment for the overlay.
	 * Default is ALIGN_RIGHT. For edges, the overlay
	 * always appears in the center of the edge.
	 */
	protected Object align = mxConstants.ALIGN_RIGHT;

	/**
	 * Holds the vertical alignment for the overlay.
	 * Default is bottom. For edges, the overlay
	 * always appears in the center of the edge.
	 */
	protected Object verticalAlign = mxConstants.ALIGN_BOTTOM;

	/**
	 * Defines the overlapping for the overlay, that is,
	 * the proportional distance from the origin to the
	 * point defined by the alignment. Default is 0.5.
	 */
	protected double defaultOverlap = 0.5;

	/**
	 * 
	 */
	public mxCellOverlay(ImageIcon icon, String warning)
	{
		this.imageIcon = icon;
		setToolTipText(warning);
		setCursor(new Cursor(Cursor.DEFAULT_CURSOR));
	}

	/**
	 * @return the alignment of the overlay, see <code>mxConstants.ALIGN_*****</code>
	 */
	public Object getAlign()
	{
		return align;
	}

	/**
	 * @param value the alignment to set, see <code>mxConstants.ALIGN_*****</code>
	 */
	public void setAlign(Object value)
	{
		align = value;
	}

	/**
	 * @return the vertical alignment, see <code>mxConstants.ALIGN_*****</code>
	 */
	public Object getVerticalAlign()
	{
		return verticalAlign;
	}

	/**
	 * @param value the vertical alignment to set, see <code>mxConstants.ALIGN_*****</code>
	 */
	public void setVerticalAlign(Object value)
	{
		verticalAlign = value;
	}

	/**
	 * 
	 */
	public void paint(Graphics g)
	{
		g.drawImage(imageIcon.getImage(), 0, 0, getWidth(), getHeight(), this);
	}

	/*
	 * (non-Javadoc)
	 * @see com.mxgraph.swing.util.mxIOverlay#getBounds(com.mxgraph.view.mxCellState)
	 */
	public mxRectangle getBounds(mxCellState state)
	{
		boolean isEdge = state.getView().getGraph().getModel()
				.isEdge(state.getCell());
		double s = state.getView().getScale();
		mxPoint pt = null;

		int w = imageIcon.getIconWidth();
		int h = imageIcon.getIconHeight();

		if (isEdge)
		{
			int n = state.getAbsolutePointCount();

			if (n % 2 == 1)
			{
				pt = state.getAbsolutePoint(n / 2 + 1);
			}
			else
			{
				int idx = n / 2;
				mxPoint p0 = state.getAbsolutePoint(idx - 1);
				mxPoint p1 = state.getAbsolutePoint(idx);
				pt = new mxPoint(p0.getX() + (p1.getX() - p0.getX()) / 2,
						p0.getY() + (p1.getY() - p0.getY()) / 2);
			}
		}
		else
		{
			pt = new mxPoint();

			if (align.equals(mxConstants.ALIGN_LEFT))
			{
				pt.setX(state.getX());
			}
			else if (align.equals(mxConstants.ALIGN_CENTER))
			{
				pt.setX(state.getX() + state.getWidth() / 2);
			}
			else
			{
				pt.setX(state.getX() + state.getWidth());
			}

			if (verticalAlign.equals(mxConstants.ALIGN_TOP))
			{
				pt.setY(state.getY());
			}
			else if (verticalAlign.equals(mxConstants.ALIGN_MIDDLE))
			{
				pt.setY(state.getY() + state.getHeight() / 2);
			}
			else
			{
				pt.setY(state.getY() + state.getHeight());
			}
		}

		return new mxRectangle(pt.getX() - w * defaultOverlap * s, pt.getY()
				- h * defaultOverlap * s, w * s, h * s);
	}

}