001/* ================================================
002 * JFreeChart-FX : JavaFX extensions for JFreeChart
003 * ================================================
004 *
005 * (C) Copyright 2017-2021, by Object Refinery Limited and Contributors.
006 *
007 * Project Info:  https://github.com/jfree/jfreechart-fx
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
022 * USA.
023 *
024 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025 * Other names may be trademarks of their respective owners.]
026 *
027 * ------------------
028 * ZoomHandlerFX.java
029 * ------------------
030 * (C) Copyright 2014-2021, by Object Refinery Limited and Contributors.
031 *
032 * Original Author:  David Gilbert (for Object Refinery Limited);
033 * Contributor(s):   -;
034 *
035 */
036
037package org.jfree.chart.fx.interaction;
038
039import java.awt.geom.Point2D;
040import java.awt.geom.Rectangle2D;
041import javafx.scene.input.MouseEvent;
042import org.jfree.chart.fx.ChartCanvas;
043import org.jfree.chart.fx.ChartViewer;
044import org.jfree.chart.plot.Plot;
045import org.jfree.chart.plot.PlotRenderingInfo;
046import org.jfree.chart.plot.Zoomable;
047import org.jfree.chart.util.ShapeUtils;
048
049/**
050 * Handles drag zooming of charts on a {@link ChartCanvas}.  This 
051 * handler should be configured with the required modifier keys and installed 
052 * as a live handler (not an auxiliary handler).  This handler only works for
053 * a <b>ChartCanvas</b> that is embedded in a {@link ChartViewer}, since it 
054 * relies on the <b>ChartViewer</b> for drawing the zoom rectangle.
055 */
056public class ZoomHandlerFX extends AbstractMouseHandlerFX {
057
058    /** The viewer is used to overlay the zoom rectangle. */
059    private ChartViewer viewer;
060    
061    /** The starting point for the zoom. */
062    private Point2D startPoint;
063    
064    /**
065     * Creates a new instance with no modifier keys required.
066     * 
067     * @param id  the handler ID ({@code null} not permitted).
068     * @param parent  the chart viewer.
069     */
070    public ZoomHandlerFX(String id, ChartViewer parent) { 
071        this(id, parent, false, false, false, false);
072    }
073    
074    /**
075     * Creates a new instance that will be activated using the specified 
076     * combination of modifier keys.
077     * 
078     * @param id  the handler ID ({@code null} not permitted).
079     * @param parent  the chart viewer.
080     * @param altKey  require ALT key?
081     * @param ctrlKey  require CTRL key?
082     * @param metaKey  require META key?
083     * @param shiftKey   require SHIFT key?
084     */
085    public ZoomHandlerFX(String id, ChartViewer parent, boolean altKey, 
086            boolean ctrlKey, boolean metaKey, boolean shiftKey) {
087        super(id, altKey, ctrlKey, metaKey, shiftKey);
088        this.viewer = parent;
089    }
090    
091    /**
092     * Handles a mouse pressed event by recording the initial mouse pointer
093     * location.
094     * 
095     * @param canvas  the JavaFX canvas ({@code null} not permitted).
096     * @param e  the mouse event ({@code null} not permitted).
097     */
098    @Override
099    public void handleMousePressed(ChartCanvas canvas, MouseEvent e) {
100        if (canvas.getChart() == null) {
101                return;
102        }
103        Point2D pt = new Point2D.Double(e.getX(), e.getY());
104        Rectangle2D dataArea = canvas.findDataArea(pt);
105        if (dataArea != null) {
106            this.startPoint = ShapeUtils.getPointInRectangle(e.getX(),
107                    e.getY(), dataArea);
108        } else {
109            this.startPoint = null;
110            canvas.clearLiveHandler();
111        }
112    }
113    
114    /**
115     * Handles a mouse dragged event by updating the zoom rectangle displayed
116     * in the ChartViewer.
117     * 
118     * @param canvas  the JavaFX canvas ({@code null} not permitted).
119     * @param e  the mouse event ({@code null} not permitted).
120     */
121    @Override
122    public void handleMouseDragged(ChartCanvas canvas, MouseEvent e) {
123        if (this.startPoint == null) {
124            //no initial zoom rectangle exists but the handler is set
125            //as life handler unregister
126            canvas.clearLiveHandler();
127            return;
128        }
129        if (canvas.getChart() == null) {
130                return;
131        }
132
133        boolean hZoom, vZoom;
134        Plot p = canvas.getChart().getPlot();
135        if (!(p instanceof Zoomable)) {
136            return;
137        }
138        Zoomable z = (Zoomable) p;
139        if (z.getOrientation().isHorizontal()) {
140            hZoom = z.isRangeZoomable();
141            vZoom = z.isDomainZoomable();
142        } else {
143            hZoom = z.isDomainZoomable();
144            vZoom = z.isRangeZoomable();
145        }
146        Rectangle2D dataArea = canvas.findDataArea(this.startPoint);
147        
148        double x = this.startPoint.getX();
149        double y = this.startPoint.getY();
150        double w = 0;
151        double h = 0;
152        if (hZoom && vZoom) {
153            // selected rectangle shouldn't extend outside the data area...
154            double xmax = Math.min(e.getX(), dataArea.getMaxX());
155            double ymax = Math.min(e.getY(), dataArea.getMaxY());
156            w = xmax - this.startPoint.getX();
157            h = ymax - this.startPoint.getY();
158        }
159        else if (hZoom) {
160            double xmax = Math.min(e.getX(), dataArea.getMaxX());
161            y = dataArea.getMinY();
162            w = xmax - this.startPoint.getX();
163            h = dataArea.getHeight();
164        }
165        else if (vZoom) {
166            double ymax = Math.min(e.getY(), dataArea.getMaxY());
167            x = dataArea.getMinX();
168            w = dataArea.getWidth();
169            h = ymax - this.startPoint.getY();
170        }
171        this.viewer.showZoomRectangle(x, y, w, h);
172    }
173
174    @Override
175    public void handleMouseReleased(ChartCanvas canvas, MouseEvent e) {
176        if (canvas.getChart() == null) {
177                return;
178        }
179        Plot p = canvas.getChart().getPlot();
180        if (!(p instanceof Zoomable)) {
181            return;
182        }
183        boolean hZoom, vZoom;
184        Zoomable z = (Zoomable) p;
185        if (z.getOrientation().isHorizontal()) {
186            hZoom = z.isRangeZoomable();
187            vZoom = z.isDomainZoomable();
188        } else {
189            hZoom = z.isDomainZoomable();
190            vZoom = z.isRangeZoomable();
191        }
192
193        boolean zoomTrigger1 = hZoom && Math.abs(e.getX()
194                - this.startPoint.getX()) >= 10;
195        boolean zoomTrigger2 = vZoom && Math.abs(e.getY()
196                - this.startPoint.getY()) >= 10;
197        if (zoomTrigger1 || zoomTrigger2) {
198            Point2D endPoint = new Point2D.Double(e.getX(), e.getY());
199            PlotRenderingInfo pri = canvas.getRenderingInfo().getPlotInfo();
200            if ((hZoom && (e.getX() < this.startPoint.getX()))
201                    || (vZoom && (e.getY() < this.startPoint.getY()))) {
202                boolean saved = p.isNotify();
203                p.setNotify(false);
204                z.zoomDomainAxes(0, pri, endPoint);
205                z.zoomRangeAxes(0, pri, endPoint);
206                p.setNotify(saved);
207            } else {
208                double x = this.startPoint.getX();
209                double y = this.startPoint.getY();
210                double w = e.getX() - x;
211                double h = e.getY() - y;
212                Rectangle2D dataArea = canvas.findDataArea(this.startPoint);
213                double maxX = dataArea.getMaxX();
214                double maxY = dataArea.getMaxY();
215                // for mouseReleased event, (horizontalZoom || verticalZoom)
216                // will be true, so we can just test for either being false;
217                // otherwise both are true
218                if (!vZoom) {
219                    y = dataArea.getMinY();
220                    w = Math.min(w, maxX - this.startPoint.getX());
221                    h = dataArea.getHeight();
222                }
223                else if (!hZoom) {
224                    x = dataArea.getMinX();
225                    w = dataArea.getWidth();
226                    h = Math.min(h, maxY - this.startPoint.getY());
227                }
228                else {
229                    w = Math.min(w, maxX - this.startPoint.getX());
230                    h = Math.min(h, maxY - this.startPoint.getY());
231                }
232                Rectangle2D zoomArea = new Rectangle2D.Double(x, y, w, h);
233                if (!zoomArea.isEmpty()) {        
234                    boolean saved = p.isNotify();
235                    p.setNotify(false);
236                    double pw0 = percentW(x, dataArea);
237                    double pw1 = percentW(x + w, dataArea);
238                    double ph0 = percentH(y, dataArea);
239                    double ph1 = percentH(y + h, dataArea);
240                    PlotRenderingInfo info 
241                            = this.viewer.getRenderingInfo().getPlotInfo();
242                    if (z.getOrientation().isVertical()) {
243                        z.zoomDomainAxes(pw0, pw1, info, endPoint);
244                        z.zoomRangeAxes(1 - ph1, 1 - ph0, info, endPoint);
245                    } else {
246                        z.zoomRangeAxes(pw0, pw1, info, endPoint);
247                        z.zoomDomainAxes(1 - ph1, 1 - ph0, info, endPoint);
248                    }
249                    p.setNotify(saved);
250                }
251            }
252        }
253        this.viewer.hideZoomRectangle();
254        this.startPoint = null;
255        canvas.clearLiveHandler();
256    }
257
258    private double percentW(double x, Rectangle2D r) {
259        return (x - r.getMinX()) / r.getWidth();
260    }
261    
262    private double percentH(double y, Rectangle2D r) {
263        return (y - r.getMinY()) / r.getHeight();
264    }
265}