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     /**
  56      * Standard constructor.
  57      *
  58      * @param histogram
  59      *            The parent histogram object
  60      * @param canvas
  61      *            The canvas
  62      * @param start
  63      *            The start time of the zoom area
  64      * @param end
  65      *            The end time of the zoom area
  66      */
  67     public HistogramZoom(Histogram histogram, Canvas canvas, long start,
  68             long end) {
  69         fHistogram = histogram;
  70         fCanvas = canvas;
  71         fAbsoluteStartTime = start;
  72         fAbsoluteEndTime = end;
  73         fMinWindowSize = fCanvas.getBounds().x;
  74
  75         fRangeStartTime = fAbsoluteStartTime;
  76         fRangeDuration = fAbsoluteStartTime + fMinWindowSize;
  77
  78         canvas.addMouseWheelListener(this);
  79     }
  80
  81     // ------------------------------------------------------------------------
  82     // Accessors
  83     // ------------------------------------------------------------------------
  84
  85     /**
  86      * Get start time of the zoom window.
  87      * @return the start time.
  88      */
  89     public synchronized long getStartTime() {
  90         return fRangeStartTime;
  91     }
  92
  93     /**
  94      * Get the end time of the zoom window.
  95      * @return the end time
  96      */
  97     public synchronized long getEndTime() {
  98         return fRangeStartTime + fRangeDuration;
  99     }
 100
 101     /**
 102      * Get the duration of the zoom window.
 103      * @return the duration of the zoom window.
 104      */
 105     public synchronized long getDuration() {
 106         return fRangeDuration;
 107     }
 108
 109     // ------------------------------------------------------------------------
 110     // Operations
 111     // ------------------------------------------------------------------------
 112
 113     /**
 114      * Stops the zooming (multiple consecutive execution)
 115      */
 116     public synchronized void stop() {
 117         if (fScrollCounter != null) {
 118             fScrollCounter.interrupt();
 119             fScrollCounter = null;
 120         }
 121     }
 122
 123     /**
 124      * The the full time range of the histogram
 125      *
 126      * @param startTime the start time the histogram
 127      * @param endTime the end time of the histogram
 128      */
 129     public synchronized void setFullRange(long startTime, long endTime) {
 130         fAbsoluteStartTime = startTime;
 131         fAbsoluteEndTime = endTime;
 132     }
 133
 134     /**
 135      * Sets the new zoom window
 136      * @param startTime the start time
 137      * @param duration the duration
 138      */
 139     public synchronized void setNewRange(long startTime, long duration) {
 140         long realStart = startTime;
 141
 142         if (realStart < fAbsoluteStartTime) {
 143             realStart = fAbsoluteStartTime;
 144         }
 145
 146         long endTime = realStart + duration;
 147         if (endTime > fAbsoluteEndTime) {
 148             endTime = fAbsoluteEndTime;
 149             if (endTime - duration > fAbsoluteStartTime) {
 150                 realStart = endTime - duration;
 151             } else {
 152                 realStart = fAbsoluteStartTime;
 153             }
 154         }
 155
 156         fRangeStartTime = realStart;
 157         fRangeDuration = endTime - realStart;
 158     }
 159
 160     // ------------------------------------------------------------------------
 161     // MouseWheelListener
 162     // ------------------------------------------------------------------------
 163
 164     @Override
 165     public synchronized void mouseScrolled(MouseEvent event) {
 166         if (fScrollCounter == null) {
 167             fScrollCounter = new MouseScrollCounter(this);
 168             fScrollCounter.start();
 169         }
 170         fScrollCounter.incrementMouseScroll(event.count);
 171     }
 172
 173     private synchronized void zoom(int nbClicks) {
 174         // The job is finished
 175         fScrollCounter = null;
 176
 177         // Compute the new time range
 178         long requestedRange = (nbClicks > 0) ? Math.round(ZOOM_FACTOR * fRangeDuration) : (long) Math.ceil(fRangeDuration * (1.0 / ZOOM_FACTOR));
 179
 180         // Distribute delta and adjust for boundaries
 181         long requestedStart = validateStart(fRangeStartTime + (fRangeDuration - requestedRange) / 2);
 182         long requestedEnd = validateEnd(requestedStart, requestedStart + requestedRange);
 183         requestedStart = validateStart(requestedEnd - requestedRange);
 184
 185         fHistogram.updateTimeRange(requestedStart, requestedEnd);
 186     }
 187
 188     private long validateStart(long start) {
 189         long realStart = start;
 190
 191         if (realStart < fAbsoluteStartTime) {
 192             realStart = fAbsoluteStartTime;
 193         }
 194         if (realStart > fAbsoluteEndTime) {
 195             realStart = fAbsoluteEndTime - fMinWindowSize;
 196         }
 197         return realStart;
 198     }
 199
 200     private long validateEnd(long start, long end) {
 201         long realEnd = end;
 202
 203         if (realEnd > fAbsoluteEndTime) {
 204             realEnd = fAbsoluteEndTime;
 205         }
 206         if (realEnd < start + fMinWindowSize) {
 207             realEnd = start + fMinWindowSize;
 208         }
 209         return realEnd;
 210     }
 211
 212     // ------------------------------------------------------------------------
 213     // DelayedMouseScroll
 214     // ------------------------------------------------------------------------
 215
 216     private static class MouseScrollCounter extends Thread {
 217
 218         // --------------------------------------------------------------------
 219         // Constants
 220         // --------------------------------------------------------------------
 221
 222         private final static long QUIET_TIME = 100L;
 223         private final static long POLLING_INTERVAL = 10L;
 224
 225         // --------------------------------------------------------------------
 226         // Attributes
 227         // --------------------------------------------------------------------
 228
 229         private HistogramZoom fZoom = null;
 230
 231         private long fLastPoolTime = 0L;
 232         private int nbScrollClick = 0;
 233
 234         // --------------------------------------------------------------------
 235         // Constructors
 236         // --------------------------------------------------------------------
 237
 238         /**
 239          * Constructor of inner class to handle consecutive scrolls of mouse wheel.
 240          * @param zoom the histogram zoom reference
 241          */
 242         public MouseScrollCounter(HistogramZoom zoom) {
 243             fZoom = zoom;
 244             fLastPoolTime = System.currentTimeMillis();
 245         }
 246
 247         // --------------------------------------------------------------------
 248         // Operation
 249         // --------------------------------------------------------------------
 250
 251         /**
 252          * Increments the number of scroll clicks.
 253          * @param nbScrolls the number to add to the current value
 254          */
 255         public void incrementMouseScroll(int nbScrolls) {
 256             fLastPoolTime = System.currentTimeMillis();
 257             nbScrollClick += nbScrolls;
 258         }
 259
 260         // --------------------------------------------------------------------
 261         // Thread
 262         // --------------------------------------------------------------------
 263
 264         @Override
 265         public void run() {
 266             while ((System.currentTimeMillis() - fLastPoolTime) < QUIET_TIME) {
 267                 try {
 268                     Thread.sleep(POLLING_INTERVAL);
 269                 } catch (Exception e) {
 270                     return;
 271                 }
 272             }
 273             // Done waiting. Notify the histogram.
 274             if (!isInterrupted()) {
 275                 fZoom.zoom(nbScrollClick);
 276             }
 277         }
 278     }
 279
 280 }