ScalablePolygonShape.java

/*******************************************************************************
 * Copyright (c) 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:
 *    Alexander Shatalin (Borland) - initial API and implementation
 *******************************************************************************/
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 org.eclipse.draw2d.geometry.PointList} as a polygonal shape 
 * scaled in accordance with bounds to fill whole figure.
 * This class is similar to {@link PolygonShape}, except the polygon should be 
 * scaled expanded/compressed to fit in current bounds. 
 * 
 * @since 3.5
 */
public class ScalablePolygonShape extends AbstractPointListShape {
	
	private static final Rectangle TEMPLATEBOUNDS = Rectangle.SINGLETON;
	
	private PointList scaledPoints;

	protected boolean shapeContainsPoint(int x, int y) {
		Point location = getLocation();
		return Geometry.polygonContainsPoint(getScaledPoints(), x - location.x, y - location.y);
	}

	protected void fillShape(Graphics graphics) {
		graphics.pushState();
		graphics.translate(getLocation());
		graphics.fillPolygon(getScaledPoints());
		graphics.popState();
	}

	protected void outlineShape(Graphics graphics) {
		graphics.pushState();
		graphics.translate(getLocation());
		graphics.drawPolygon(getScaledPoints());
		graphics.popState();
	}
	
	private Rectangle getTemplateBounds() {
		TEMPLATEBOUNDS.setLocation(0, 0);
		TEMPLATEBOUNDS.setSize(0, 0);
		int[] intArray = points.toIntArray();
		for (int i = 0; i < intArray.length; ) {
			int x = intArray[i++];
			if (x > TEMPLATEBOUNDS.width) {
				TEMPLATEBOUNDS.width = x;
			}
			int y = intArray[i++];
			if (y > TEMPLATEBOUNDS.height) {
				TEMPLATEBOUNDS.height = y;
			}
		}
		return TEMPLATEBOUNDS;
	}
	
	public PointList getScaledPoints() {
		if (scaledPoints != null) {
			return scaledPoints;
		}
		Rectangle pointsBounds = getTemplateBounds();
		Rectangle actualBounds = getBounds();
		double xScale = actualBounds.width > lineWidth ? ((double) actualBounds.width - lineWidth) / pointsBounds.width : 0;
		double yScale = actualBounds.height > lineWidth ? ((double) actualBounds.height - lineWidth) / pointsBounds.height : 0;
		double halfLineWidth = ((double) lineWidth) / 2;

		int[] pointsArray = points.getCopy().toIntArray();
		for (int i = 0; i < pointsArray.length; i = i + 2) {
			pointsArray[i] = (int) (Math.floor(pointsArray[i] * xScale) + halfLineWidth);
			pointsArray[i + 1] = (int) (Math.floor(pointsArray[i + 1] * yScale) + halfLineWidth);	
		}
		return scaledPoints = new PointList(pointsArray);
	}
	
	public void addPoint(Point pt) {
		scaledPoints = null;
		super.addPoint(pt);
	}
	
	public void insertPoint(Point pt, int index) {
		scaledPoints = null;
		super.insertPoint(pt, index);
	}
	
	public void removeAllPoints() {
		scaledPoints = null;
		super.removeAllPoints();
	}

	public void removePoint(int index) {
		scaledPoints = null;
		super.removePoint(index);
	}
	
	public void setStart(Point start) {
		scaledPoints = null;
		super.setStart(start);
	}
	
	public void setEnd(Point end) {
		scaledPoints = null;
		super.setEnd(end);
	}
	
	public void setPoint(Point pt, int index) {
		scaledPoints = null;
		super.setPoint(pt, index);
	}
	
	public void setPoints(PointList points) {
		scaledPoints = null;
		super.setPoints(points);
	}
	
	public void setBounds(Rectangle rect) {
		scaledPoints = null;
		super.setBounds(rect);
	}
	
	public void setLineWidth(int w) {
		scaledPoints = null;
		super.setLineWidth(w);
	}

}