FitZoom.java

/**
 * Copyright (C) 2009, 2010 SC 4ViewSoft SRL
 *  
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *  
 *      http://www.apache.org/licenses/LICENSE-2.0
 *  
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.androsz.achartengine.tools;

import com.androsz.achartengine.chart.XYChart;
import com.androsz.achartengine.model.XYSeries;

public class FitZoom extends AbstractTool {

	/**
	 * Builds an instance of the fit zoom tool.
	 * 
	 * @param chart
	 *            the XY chart
	 */
	public FitZoom(XYChart chart) {
		super(chart);
	}

	/**
	 * Apply the tool.
	 */
	public void apply() {
		if (mChart.getDataset() == null)
			return;
		if (mRenderer.isInitialRangeSet()) {
			mRenderer.setRange(mRenderer.getInitialRange());
		} else {
			final XYSeries[] series = mChart.getDataset().getSeries();
			double[] range = null;
			final int length = series.length;
			if (length > 0) {
				range = new double[] {
						series[0].getMinX(),
						series[0].getMaxX(),
						Math.min(mChart.getDefaultMinimum(),
								series[0].getMinY()), series[0].getMaxY() };
				for (int i = 1; i < length; i++) {
					range[0] = Math.min(range[0], series[i].getMinX());
					range[1] = Math.max(range[1], series[i].getMaxX());
					range[2] = Math.min(range[2], series[i].getMinY());
					range[3] = Math.max(range[3], series[i].getMaxY());
				}
				final double marginX = Math.abs(range[1] - range[0]) / 40;
				final double marginY = Math.abs(range[3] - range[2]) / 40;
				mRenderer.setRange(new double[] { range[0] - marginX,
						range[1] + marginX, range[2] - marginY,
						range[3] + marginY });
			}
		}
	}
}