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

   1 /*******************************************************************************
   2  * Copyright (c) 2011, 2014 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  *   Patrick Tasse - Update for mouse wheel zoom
  13  *******************************************************************************/
  14
  15 package org.eclipse.tracecompass.tmf.ui.views.histogram;
  16
  17 import org.eclipse.swt.events.KeyEvent;
  18 import org.eclipse.swt.events.KeyListener;
  19 import org.eclipse.swt.events.MouseEvent;
  20 import org.eclipse.swt.events.MouseWheelListener;
  21
  22 /**
  23  * Class to handle zooming within histogram windows..
  24  *
  25  * @version 1.0
  26  * @author Francois Chouinard
  27  * <p>
  28  */
  29 public class HistogramZoom implements MouseWheelListener, KeyListener {
  30
  31     // ------------------------------------------------------------------------
  32     // Constants
  33     // ------------------------------------------------------------------------
  34
  35     private final static double ZOOM_FACTOR = 0.8;
  36
  37     // ------------------------------------------------------------------------
  38     // Attributes
  39     // ------------------------------------------------------------------------
  40
  41     private final Histogram fHistogram;
  42
  43     private long fAbsoluteStartTime;
  44     private long fAbsoluteEndTime;
  45     private final long fMinWindowSize;
  46
  47     private long fRangeStartTime;
  48     private long fRangeDuration;
  49
  50     // ------------------------------------------------------------------------
  51     // Constructors
  52     // ------------------------------------------------------------------------
  53
  54     /**
  55      * Standard constructor.
  56      *
  57      * @param histogram
  58      *            The parent histogram object
  59      * @param start
  60      *            The start time of the zoom area
  61      * @param end
  62      *            The end time of the zoom area
  63      */
  64     public HistogramZoom(Histogram histogram, long start, long end) {
  65         fHistogram = histogram;
  66         fAbsoluteStartTime = start;
  67         fAbsoluteEndTime = end;
  68         fMinWindowSize = 0;
  69
  70         fRangeStartTime = fAbsoluteStartTime;
  71         fRangeDuration = fAbsoluteStartTime + fMinWindowSize;
  72
  73         histogram.addMouseWheelListener(this);
  74         histogram.addKeyListener(this);
  75     }
  76
  77     // ------------------------------------------------------------------------
  78     // Accessors
  79     // ------------------------------------------------------------------------
  80
  81     /**
  82      * Get start time of the zoom window.
  83      * @return the start time.
  84      */
  85     public synchronized long getStartTime() {
  86         return fRangeStartTime;
  87     }
  88
  89     /**
  90      * Get the end time of the zoom window.
  91      * @return the end time
  92      */
  93     public synchronized long getEndTime() {
  94         return fRangeStartTime + fRangeDuration;
  95     }
  96
  97     /**
  98      * Get the duration of the zoom window.
  99      * @return the duration of the zoom window.
 100      */
 101     public synchronized long getDuration() {
 102         return fRangeDuration;
 103     }
 104
 105     // ------------------------------------------------------------------------
 106     // Operations
 107     // ------------------------------------------------------------------------
 108
 109     /**
 110      * The the full time range of the histogram
 111      *
 112      * @param startTime the start time the histogram
 113      * @param endTime the end time of the histogram
 114      */
 115     public synchronized void setFullRange(long startTime, long endTime) {
 116         fAbsoluteStartTime = startTime;
 117         fAbsoluteEndTime = endTime;
 118     }
 119
 120     /**
 121      * Sets the new zoom window
 122      * @param startTime the start time
 123      * @param duration the duration
 124      */
 125     public synchronized void setNewRange(long startTime, long duration) {
 126         long realStart = startTime;
 127
 128         if (realStart < fAbsoluteStartTime) {
 129             realStart = fAbsoluteStartTime;
 130         }
 131
 132         long endTime = realStart + duration;
 133         if (endTime > fAbsoluteEndTime) {
 134             endTime = fAbsoluteEndTime;
 135             if (endTime - duration > fAbsoluteStartTime) {
 136                 realStart = endTime - duration;
 137             } else {
 138                 realStart = fAbsoluteStartTime;
 139             }
 140         }
 141
 142         fRangeStartTime = realStart;
 143         fRangeDuration = endTime - realStart;
 144     }
 145
 146     // ------------------------------------------------------------------------
 147     // MouseWheelListener
 148     // ------------------------------------------------------------------------
 149
 150     @Override
 151     public void mouseScrolled(MouseEvent event) {
 152         zoom(event.count);
 153     }
 154
 155     @Override
 156     public void keyPressed(KeyEvent e) {
 157         if (e.character == '+') {
 158             zoom(1);
 159         } else if (e.character == '-') {
 160             zoom(-1);
 161         }
 162     }
 163
 164     @Override
 165     public void keyReleased(KeyEvent e) {
 166     }
 167
 168     private synchronized void zoom(int nbClicks) {
 169         // Compute the new time range
 170         long requestedRange = (nbClicks > 0) ? Math.round(ZOOM_FACTOR * fRangeDuration) : (long) Math.ceil(fRangeDuration * (1.0 / ZOOM_FACTOR));
 171
 172         // Distribute delta and adjust for boundaries
 173         long requestedStart = validateStart(fRangeStartTime + (fRangeDuration - requestedRange) / 2);
 174         long requestedEnd = validateEnd(requestedStart, requestedStart + requestedRange);
 175         requestedStart = validateStart(requestedEnd - requestedRange);
 176
 177         fHistogram.updateTimeRange(requestedStart, requestedEnd);
 178     }
 179
 180     private long validateStart(long start) {
 181         long realStart = start;
 182
 183         if (realStart < fAbsoluteStartTime) {
 184             realStart = fAbsoluteStartTime;
 185         }
 186         if (realStart > fAbsoluteEndTime) {
 187             realStart = fAbsoluteEndTime - fMinWindowSize;
 188         }
 189         return realStart;
 190     }
 191
 192     private long validateEnd(long start, long end) {
 193         long realEnd = end;
 194
 195         if (realEnd > fAbsoluteEndTime) {
 196             realEnd = fAbsoluteEndTime;
 197         }
 198         if (realEnd < start + fMinWindowSize) {
 199             realEnd = start + fMinWindowSize;
 200         }
 201         return realEnd;
 202     }
 203 }