org.eclipse.linuxtools.tmf.ui/src/org/eclipse/linuxtools/tmf/ui/views/histogram/HistogramZoom.java

   1 /*******************************************************************************
   2  * Copyright (c) 2011, 2012 Ericsson
   3  *
   4  * All rights reserved. This program and the accompanying materials are
   5  * made available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *   Francois Chouinard - Initial API and implementation
  11  *   Francois Chouinard - Moved from LTTng to TMF
  12  *******************************************************************************/
  13
  14 package org.eclipse.linuxtools.tmf.ui.views.histogram;
  15
  16 import org.eclipse.swt.events.MouseEvent;
  17 import org.eclipse.swt.events.MouseWheelListener;
  18 import org.eclipse.swt.widgets.Canvas;
  19
  20 /**
  21  * Class to handle zooming within histogram windows..
  22  *
  23  * @version 1.0
  24  * @author Francois Chouinard
  25  * <p>
  26  */
  27 public class HistogramZoom implements MouseWheelListener {
  28
  29     // ------------------------------------------------------------------------
  30     // Constants
  31     // ------------------------------------------------------------------------
  32
  33     private final static double ZOOM_FACTOR = 0.8;
  34
  35     // ------------------------------------------------------------------------
  36     // Attributes
  37     // ------------------------------------------------------------------------
  38
  39     private final Histogram fHistogram;
  40     private final Canvas fCanvas;
  41
  42     private long fAbsoluteStartTime;
  43     private long fAbsoluteEndTime;
  44     private final long fMinWindowSize;
  45
  46     private long fRangeStartTime;
  47     private long fRangeDuration;
  48
  49     private MouseScrollCounter fScrollCounter;
  50
  51     // ------------------------------------------------------------------------
  52     // Constructors
  53     // ------------------------------------------------------------------------
  54
  55     public HistogramZoom(Histogram histogram, Canvas canvas, long start, long end) {
  56         fHistogram = histogram;
  57         fCanvas = canvas;
  58         fAbsoluteStartTime = start;
  59         fAbsoluteEndTime = end;
  60         fMinWindowSize = fCanvas.getBounds().x;
  61
  62         fRangeStartTime = fAbsoluteStartTime;
  63         fRangeDuration = fAbsoluteStartTime + fMinWindowSize;
  64
  65         canvas.addMouseWheelListener(this);
  66     }
  67
  68     // ------------------------------------------------------------------------
  69     // Accessors
  70     // ------------------------------------------------------------------------
  71
  72     /**
  73      * Get start time of the zoom window.
  74      * @return the start time.
  75      */
  76     public synchronized long getStartTime() {
  77         return fRangeStartTime;
  78     }
  79
  80     /**
  81      * Get the end time of the zoom window.
  82      * @return the end time
  83      */
  84     public synchronized long getEndTime() {
  85         return fRangeStartTime + fRangeDuration;
  86     }
  87
  88     /**
  89      * Get the duration of the zoom window.
  90      * @return the duration of the zoom window.
  91      */
  92     public synchronized long getDuration() {
  93         return fRangeDuration;
  94     }
  95
  96     // ------------------------------------------------------------------------
  97     // Operations
  98     // ------------------------------------------------------------------------
  99
 100     /**
 101      * Stops the zooming (multiple consecutive execution)
 102      */
 103     public synchronized void stop() {
 104         if (fScrollCounter != null) {
 105             fScrollCounter.interrupt();
 106             fScrollCounter = null;
 107         }
 108     }
 109
 110     /**
 111      * The the full time range of the histogram
 112      *
 113      * @param startTime the start time the histogram
 114      * @param endTime the end time of the histogram
 115      */
 116     public synchronized void setFullRange(long startTime, long endTime) {
 117         fAbsoluteStartTime = startTime;
 118         fAbsoluteEndTime = endTime;
 119     }
 120
 121     /**
 122      * Sets the new zoom window
 123      * @param startTime the start time
 124      * @param duration the duration
 125      */
 126     public synchronized void setNewRange(long startTime, long duration) {
 127         if (startTime < fAbsoluteStartTime)
 128             startTime = fAbsoluteStartTime;
 129
 130         long endTime = startTime + duration;
 131         if (endTime > fAbsoluteEndTime) {
 132             endTime = fAbsoluteEndTime;
 133             if (endTime - duration > fAbsoluteStartTime)
 134                 startTime = endTime - duration;
 135             else {
 136                 startTime = fAbsoluteStartTime;
 137             }
 138         }
 139
 140         fRangeStartTime = startTime;
 141         fRangeDuration = endTime - startTime;
 142     }
 143
 144     // ------------------------------------------------------------------------
 145     // MouseWheelListener
 146     // ------------------------------------------------------------------------
 147
 148     private long fMouseTimestamp = 0;
 149
 150     @Override
 151     public synchronized void mouseScrolled(MouseEvent event) {
 152         if (fScrollCounter == null) {
 153             fScrollCounter = new MouseScrollCounter(this);
 154             fScrollCounter.start();
 155             fMouseTimestamp = fHistogram.getTimestamp(event.x);
 156         }
 157         fScrollCounter.incrementMouseScroll(event.count);
 158     }
 159
 160     private synchronized void zoom(int nbClicks) {
 161         // The job is finished
 162         fScrollCounter = null;
 163
 164         // Compute the new time range
 165         long requestedRange = (nbClicks > 0) ? Math.round(ZOOM_FACTOR * fRangeDuration) : (long) Math.ceil(fRangeDuration * (1.0 / ZOOM_FACTOR));
 166
 167         // Perform a proportional zoom wrt the mouse position
 168         double ratio = ((double) (fMouseTimestamp - fRangeStartTime)) / fRangeDuration;
 169         long requestedStart = validateStart(fRangeStartTime + (long) ((fRangeDuration - requestedRange) * ratio));
 170         long requestedEnd = validateEnd(requestedStart, requestedStart + requestedRange);
 171         requestedStart = validateStart(requestedEnd - requestedRange);
 172
 173         fHistogram.updateTimeRange(requestedStart, requestedEnd);
 174     }
 175
 176     private long validateStart(long start) {
 177         if (start < fAbsoluteStartTime)
 178             start = fAbsoluteStartTime;
 179         if (start > fAbsoluteEndTime)
 180             start = fAbsoluteEndTime - fMinWindowSize;
 181         return start;
 182     }
 183
 184     private long validateEnd(long start, long end) {
 185         if (end > fAbsoluteEndTime)
 186             end = fAbsoluteEndTime;
 187         if (end < start + fMinWindowSize)
 188             end = start + fMinWindowSize;
 189         return end;
 190     }
 191
 192     // ------------------------------------------------------------------------
 193     // DelayedMouseScroll
 194     // ------------------------------------------------------------------------
 195
 196     private static class MouseScrollCounter extends Thread {
 197
 198         // --------------------------------------------------------------------
 199         // Constants
 200         // --------------------------------------------------------------------
 201
 202         private final static long QUIET_TIME = 100L;
 203         private final static long POLLING_INTERVAL = 10L;
 204
 205         // --------------------------------------------------------------------
 206         // Attributes
 207         // --------------------------------------------------------------------
 208
 209         private HistogramZoom fZoom = null;
 210
 211         private long fLastPoolTime = 0L;
 212         private int nbScrollClick = 0;
 213
 214         // --------------------------------------------------------------------
 215         // Constructors
 216         // --------------------------------------------------------------------
 217
 218         /**
 219          * Constructor of inner class to handle consecutive scrolls of mouse wheel.
 220          * @param zoom the histogram zoom reference
 221          */
 222         public MouseScrollCounter(HistogramZoom zoom) {
 223             fZoom = zoom;
 224             fLastPoolTime = System.currentTimeMillis();
 225         }
 226
 227         // --------------------------------------------------------------------
 228         // Operation
 229         // --------------------------------------------------------------------
 230
 231         /**
 232          * Increments the number of scroll clicks.
 233          * @param nbScrolls the number to add to the current value
 234          */
 235         public void incrementMouseScroll(int nbScrolls) {
 236             fLastPoolTime = System.currentTimeMillis();
 237             nbScrollClick += nbScrolls;
 238         }
 239
 240         // --------------------------------------------------------------------
 241         // Thread
 242         // --------------------------------------------------------------------
 243
 244         @Override
 245         public void run() {
 246             while ((System.currentTimeMillis() - fLastPoolTime) < QUIET_TIME) {
 247                 try {
 248                     Thread.sleep(POLLING_INTERVAL);
 249                 } catch (Exception e) {
 250                     return;
 251                 }
 252             }
 253             // Done waiting. Notify the histogram.
 254             if (!isInterrupted())
 255                 fZoom.zoom(nbScrollClick);
 256         }
 257     }
 258
 259 }