Polyline.java

/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Alexander Shatalin (Borland) - Contribution for Bug 238874
 *******************************************************************************/
package org.eclipse.draw2d;

import org.eclipse.draw2d.geometry.Geometry;
import org.eclipse.draw2d.geometry.Point;
import org.eclipse.draw2d.geometry.PointList;
import org.eclipse.draw2d.geometry.Rectangle;

/**
 * Renders a {@link PointList} as a series of line segments.  A Polyline figure should be
 * positioned by manipulating its points, <EM>NOT</EM> by calling
 * {@link Figure#setBounds(Rectangle)}.
 * <P>
 * A polyline's bounds will be calculated automatically based on its PointList.  The
 * bounds will be the smallest Rectangle large enough to render the line properly.
 * Children should not be added to a Polyline and will not affect the bounds calculation.
 */
public class Polyline
	extends AbstractPointListShape
{

private int tolerance = 2;
private static final Rectangle LINEBOUNDS = Rectangle.SINGLETON;

{
	setFill(false);
	bounds  = null;
}

/**
 * @see org.eclipse.draw2d.IFigure#containsPoint(int, int)
 */
public boolean containsPoint(int x, int y) {
	int tolerance = (int)Math.max(getLineWidthFloat() / 2.0f, this.tolerance);
	LINEBOUNDS.setBounds(getBounds());
	LINEBOUNDS.expand(tolerance, tolerance);
	if (!LINEBOUNDS.contains(x, y))
		return false;
	return shapeContainsPoint(x, y) || childrenContainsPoint(x, y);
}

protected boolean shapeContainsPoint(int x, int y) {
	return Geometry.polylineContainsPoint(points, x, y, tolerance);
}

/**
 * Null implementation for a line.
 * @see org.eclipse.draw2d.Shape#fillShape(Graphics)
 */
protected void fillShape(Graphics g) { }

/**
 * @see org.eclipse.draw2d.IFigure#getBounds()
 */
public Rectangle getBounds() {
	if (bounds == null) {
		int expand = (int)(getLineWidthFloat() / 2.0f);
		bounds = getPoints()
			.getBounds()
			.getExpanded(expand, expand);
	}
	return bounds;
}

/**
 * @return <code>false</code> because Polyline's aren't filled
 */
public boolean isOpaque() {
	return false;
}

/**
 * @see Shape#outlineShape(Graphics)
 */
protected void outlineShape(Graphics g) {
	g.drawPolyline(points);
}

/**
 * @see Figure#primTranslate(int, int)
 */
public void primTranslate(int x, int y) { }

/** 
 * Erases the Polyline and removes all of its {@link Point Points}.
 * 
 * @since 2.0
 */
public void removeAllPoints() {
	super.removeAllPoints();
	bounds = null;
}

/**
 * @see org.eclipse.draw2d.Shape#setLineWidth(int)
 */
public void setLineWidth(int w) {
	if (getLineWidthFloat() == w) {
		return;
	}
	if (w < getLineWidthFloat()) { //The bounds will become smaller, so erase must occur first.
		erase();
	}
	bounds = null;
	super.setLineWidthFloat(w);
}

/**
 * Sets the list of points to be used by this polyline connection. Removes any previously 
 * existing points. The polyline will hold onto the given list by reference.
 *
 * @param points new set of points
 * @since 2.0
 */
public void setPoints(PointList points) {
	super.setPoints(points);
	firePropertyChange(Connection.PROPERTY_POINTS, null, points);
}

/**
  * Sets the tolerance
  *
  * @param tolerance the new tolerance value of the Polyline
  */
public void setTolerance(int tolerance) {
       this.tolerance = tolerance;
}

public void repaint() {
	bounds = null;
	super.repaint();
}
}