/**
* 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 org.achartengine.tools;
import java.util.ArrayList;
import java.util.List;
import org.achartengine.chart.AbstractChart;
import org.achartengine.chart.RoundChart;
import org.achartengine.chart.XYChart;
import org.achartengine.renderer.DefaultRenderer;
/**
* The zoom tool.
*/
public class Zoom extends AbstractTool {
/** A flag to be used to know if this is a zoom in or out. */
private boolean mZoomIn;
/** The zoom rate. */
private float mZoomRate;
/** The zoom listeners. */
private List<ZoomListener> mZoomListeners = new ArrayList<ZoomListener>();
/**
* Builds the zoom tool.
*
* @param chart the chart
* @param in zoom in or out
* @param rate the zoom rate
*/
public Zoom(AbstractChart chart, boolean in, float rate) {
super(chart);
mZoomIn = in;
setZoomRate(rate);
}
/**
* Sets the zoom rate.
*
* @param rate
*/
public void setZoomRate(float rate) {
mZoomRate = rate;
}
/**
* Apply the zoom.
*/
public void apply() {
if (mChart instanceof XYChart) {
int scales = mRenderer.getScalesCount();
for (int i = 0; i < scales; i++) {
double[] range = getRange(i);
checkRange(range, i);
double[] limits = mRenderer.getZoomLimits();
boolean limited = limits != null && limits.length == 4;
double centerX = (range[0] + range[1]) / 2;
double centerY = (range[2] + range[3]) / 2;
double newWidth = range[1] - range[0];
double newHeight = range[3] - range[2];
if (mZoomIn) {
if (mRenderer.isZoomXEnabled()) {
newWidth /= mZoomRate;
}
if (mRenderer.isZoomYEnabled()) {
newHeight /= mZoomRate;
}
} else {
if (mRenderer.isZoomXEnabled()) {
newWidth *= mZoomRate;
}
if (mRenderer.isZoomYEnabled()) {
newHeight *= mZoomRate;
}
}
if (mRenderer.isZoomXEnabled()) {
double newXMin = centerX - newWidth / 2;
double newXMax = centerX + newWidth / 2;
if (!limited || limits[0] <= newXMin && limits[1] >= newXMax) {
setXRange(newXMin, newXMax, i);
}
}
if (mRenderer.isZoomYEnabled()) {
double newYMin = centerY - newHeight / 2;
double newYMax = centerY + newHeight / 2;
if (!limited || limits[2] <= newYMin && limits[3] >= newYMax) {
setYRange(newYMin, newYMax, i);
}
}
}
} else {
DefaultRenderer renderer = ((RoundChart) mChart).getRenderer();
if (mZoomIn) {
renderer.setScale(renderer.getScale() * mZoomRate);
} else {
renderer.setScale(renderer.getScale() / mZoomRate);
}
}
notifyZoomListeners(new ZoomEvent(mZoomIn, mZoomRate));
}
/**
* Notify the zoom listeners about a zoom change.
* @param e the zoom event
*/
private synchronized void notifyZoomListeners(ZoomEvent e) {
for (ZoomListener listener : mZoomListeners) {
listener.zoomApplied(e);
}
}
/**
* Notify the zoom listeners about a zoom reset.
*/
public synchronized void notifyZoomResetListeners() {
for (ZoomListener listener : mZoomListeners) {
listener.zoomReset();
}
}
/**
* Adds a new zoom listener.
*
* @param listener zoom listener
*/
public synchronized void addZoomListener(ZoomListener listener) {
mZoomListeners.add(listener);
}
/**
* Removes a zoom listener.
*
* @param listener zoom listener
*/
public synchronized void removeZoomListener(ZoomListener listener) {
mZoomListeners.add(listener);
}
}