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  * <b><u>HistogramZoom</u></b>
  22  * <p>
  23  */
  24 public class HistogramZoom implements MouseWheelListener {
  25
  26     // ------------------------------------------------------------------------
  27     // Constants
  28     // ------------------------------------------------------------------------
  29
  30     private final static double ZOOM_FACTOR = 0.8;
  31
  32     // ------------------------------------------------------------------------
  33     // Attributes
  34     // ------------------------------------------------------------------------
  35
  36     private final Histogram fHistogram;
  37     private final Canvas fCanvas;
  38
  39     private long fAbsoluteStartTime;
  40     private long fAbsoluteEndTime;
  41     private final long fMinWindowSize;
  42
  43     private long fRangeStartTime;
  44     private long fRangeDuration;
  45
  46     private MouseScrollCounter fScrollCounter;
  47
  48     // ------------------------------------------------------------------------
  49     // Constructors
  50     // ------------------------------------------------------------------------
  51
  52     public HistogramZoom(Histogram histogram, Canvas canvas, long start, long end) {
  53         fHistogram = histogram;
  54         fCanvas = canvas;
  55         fAbsoluteStartTime = start;
  56         fAbsoluteEndTime = end;
  57         fMinWindowSize = fCanvas.getBounds().x;
  58
  59         fRangeStartTime = fAbsoluteStartTime;
  60         fRangeDuration = fAbsoluteStartTime + fMinWindowSize;
  61
  62         canvas.addMouseWheelListener(this);
  63     }
  64
  65     // ------------------------------------------------------------------------
  66     // Accessors
  67     // ------------------------------------------------------------------------
  68
  69     public synchronized long getStartTime() {
  70         return fRangeStartTime;
  71     }
  72
  73     public synchronized long getEndTime() {
  74         return fRangeStartTime + fRangeDuration;
  75     }
  76
  77     public synchronized long getDuration() {
  78         return fRangeDuration;
  79     }
  80
  81     // ------------------------------------------------------------------------
  82     // Operations
  83     // ------------------------------------------------------------------------
  84
  85     public synchronized void stop() {
  86         if (fScrollCounter != null) {
  87             fScrollCounter.interrupt();
  88             fScrollCounter = null;
  89         }
  90     }
  91
  92     public synchronized void setFullRange(long startTime, long endTime) {
  93         fAbsoluteStartTime = startTime;
  94         fAbsoluteEndTime = endTime;
  95     }
  96
  97     public synchronized void setNewRange(long startTime, long duration) {
  98         if (startTime < fAbsoluteStartTime)
  99             startTime = fAbsoluteStartTime;
 100
 101         long endTime = startTime + duration;
 102         if (endTime > fAbsoluteEndTime) {
 103             endTime = fAbsoluteEndTime;
 104             if (endTime - duration > fAbsoluteStartTime)
 105                 startTime = endTime - duration;
 106             else {
 107                 startTime = fAbsoluteStartTime;
 108             }
 109         }
 110
 111         fRangeStartTime = startTime;
 112         fRangeDuration = endTime - startTime;
 113     }
 114
 115     // ------------------------------------------------------------------------
 116     // MouseWheelListener
 117     // ------------------------------------------------------------------------
 118
 119     private long fMouseTimestamp = 0;
 120
 121     @Override
 122     public synchronized void mouseScrolled(MouseEvent event) {
 123         if (fScrollCounter == null) {
 124             fScrollCounter = new MouseScrollCounter(this);
 125             fScrollCounter.start();
 126             fMouseTimestamp = fHistogram.getTimestamp(event.x);
 127         }
 128         fScrollCounter.incrementMouseScroll(event.count);
 129     }
 130
 131     private synchronized void zoom(int nbClicks) {
 132         // The job is finished
 133         fScrollCounter = null;
 134
 135         // Compute the new time range
 136         long requestedRange = (nbClicks > 0) ? Math.round(ZOOM_FACTOR * fRangeDuration) : (long) Math.ceil(fRangeDuration * (1.0 / ZOOM_FACTOR));
 137
 138         // Perform a proportional zoom wrt the mouse position
 139         double ratio = ((double) (fMouseTimestamp - fRangeStartTime)) / fRangeDuration;
 140         long requestedStart = validateStart(fRangeStartTime + (long) ((fRangeDuration - requestedRange) * ratio));
 141         long requestedEnd = validateEnd(requestedStart, requestedStart + requestedRange);
 142         requestedStart = validateStart(requestedEnd - requestedRange);
 143
 144         fHistogram.updateTimeRange(requestedStart, requestedEnd);
 145     }
 146
 147     private long validateStart(long start) {
 148         if (start < fAbsoluteStartTime)
 149             start = fAbsoluteStartTime;
 150         if (start > fAbsoluteEndTime)
 151             start = fAbsoluteEndTime - fMinWindowSize;
 152         return start;
 153     }
 154
 155     private long validateEnd(long start, long end) {
 156         if (end > fAbsoluteEndTime)
 157             end = fAbsoluteEndTime;
 158         if (end < start + fMinWindowSize)
 159             end = start + fMinWindowSize;
 160         return end;
 161     }
 162
 163     // ------------------------------------------------------------------------
 164     // DelayedMouseScroll
 165     // ------------------------------------------------------------------------
 166
 167     private static class MouseScrollCounter extends Thread {
 168
 169         // --------------------------------------------------------------------
 170         // Constants
 171         // --------------------------------------------------------------------
 172
 173         private final static long QUIET_TIME = 100L;
 174         private final static long POLLING_INTERVAL = 10L;
 175
 176         // --------------------------------------------------------------------
 177         // Attributes
 178         // --------------------------------------------------------------------
 179
 180         private HistogramZoom fZoom = null;
 181
 182         private long fLastPoolTime = 0L;
 183         private int nbScrollClick = 0;
 184
 185         // --------------------------------------------------------------------
 186         // Constructors
 187         // --------------------------------------------------------------------
 188
 189         public MouseScrollCounter(HistogramZoom zoom) {
 190             fZoom = zoom;
 191             fLastPoolTime = System.currentTimeMillis();
 192         }
 193
 194         // --------------------------------------------------------------------
 195         // Operation
 196         // --------------------------------------------------------------------
 197
 198         public void incrementMouseScroll(int nbScrolls) {
 199             fLastPoolTime = System.currentTimeMillis();
 200             nbScrollClick += nbScrolls;
 201         }
 202
 203         // --------------------------------------------------------------------
 204         // Thread
 205         // --------------------------------------------------------------------
 206
 207         @Override
 208         public void run() {
 209             while ((System.currentTimeMillis() - fLastPoolTime) < QUIET_TIME) {
 210                 try {
 211                     Thread.sleep(POLLING_INTERVAL);
 212                 } catch (Exception e) {
 213                     return;
 214                 }
 215             }
 216             // Done waiting. Notify the histogram.
 217             if (!isInterrupted())
 218                 fZoom.zoom(nbScrollClick);
 219         }
 220     }
 221
 222 }