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4bcc4ed6 | 1 | /******************************************************************************* |
60ae41e1 | 2 | * Copyright (c) 2013, 2014 Ericsson |
4bcc4ed6 BH |
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 | * Bernd Hufmann - Initial API and implementation | |
11 | *******************************************************************************/ | |
12 | ||
13 | package org.eclipse.linuxtools.tmf.ui.viewers.xycharts; | |
14 | ||
15 | import org.eclipse.swt.events.MouseEvent; | |
16 | import org.eclipse.swt.events.MouseWheelListener; | |
17 | import org.swtchart.IAxis; | |
18 | ||
19 | /** | |
20 | * Class for providing zooming based on mouse wheel. It centers the zoom on | |
21 | * mouse position. It also notifies the viewer about a change of range. | |
22 | * | |
23 | * @author Bernd Hufmann | |
24 | * @since 3.0 | |
25 | */ | |
26 | public class TmfMouseWheelZoomProvider extends TmfBaseProvider implements MouseWheelListener { | |
27 | ||
28 | // ------------------------------------------------------------------------ | |
29 | // Constants | |
30 | // ------------------------------------------------------------------------ | |
31 | private final static double ZOOM_FACTOR = 0.8; | |
32 | private final static long MIN_WINDOW_SIZE = 1; | |
33 | ||
34 | // ------------------------------------------------------------------------ | |
35 | // Constructors | |
36 | // ------------------------------------------------------------------------ | |
37 | /** | |
38 | * Standard constructor. | |
39 | * | |
40 | * @param tmfChartViewer | |
41 | * The parent histogram object | |
42 | */ | |
43 | public TmfMouseWheelZoomProvider(ITmfChartTimeProvider tmfChartViewer) { | |
44 | super(tmfChartViewer); | |
45 | register(); | |
46 | } | |
47 | ||
48 | // ------------------------------------------------------------------------ | |
49 | // TmfBaseProvider | |
50 | // ------------------------------------------------------------------------ | |
51 | @Override | |
52 | public void register() { | |
53 | getChart().getPlotArea().addMouseWheelListener(this); | |
54 | } | |
55 | ||
56 | @Override | |
57 | public void deregister() { | |
58 | if ((getChartViewer().getControl() != null) && !getChartViewer().getControl().isDisposed()) { | |
59 | getChart().getPlotArea().removeMouseWheelListener(this); | |
60 | } | |
61 | } | |
62 | ||
63 | @Override | |
64 | public void refresh() { | |
65 | // nothing to do | |
66 | } | |
67 | ||
68 | // ------------------------------------------------------------------------ | |
69 | // MouseWheelListener | |
70 | // ------------------------------------------------------------------------ | |
71 | @Override | |
72 | public synchronized void mouseScrolled(MouseEvent event) { | |
73 | ITmfChartTimeProvider viewer = getChartViewer(); | |
74 | ||
75 | long oldDuration = viewer.getWindowDuration(); | |
76 | ||
77 | if (oldDuration == 0) { | |
78 | return; | |
79 | } | |
80 | ||
81 | // Compute the new time range | |
82 | long newDuration = oldDuration; | |
83 | double ratio = 1.0; | |
84 | if (event.count > 0) { | |
85 | ratio = ZOOM_FACTOR; | |
86 | newDuration = Math.round(ZOOM_FACTOR * oldDuration); | |
87 | } else { | |
88 | ratio = 1.0 / ZOOM_FACTOR; | |
89 | newDuration = (long) Math.ceil(oldDuration * ratio); | |
90 | } | |
91 | newDuration = Math.max(MIN_WINDOW_SIZE, newDuration); | |
92 | ||
93 | // Center the zoom on mouse position, distribute new duration and adjust for boundaries. | |
94 | IAxis xAxis = getChart().getAxisSet().getXAxis(0); | |
95 | long timeAtXPos = limitXDataCoordinate(xAxis.getDataCoordinate(event.x)) + viewer.getTimeOffset(); | |
96 | // Note: ratio = newDuration/oldDuration | |
97 | long newWindowStartTime = timeAtXPos - Math.round(ratio * (timeAtXPos - viewer.getWindowStartTime())); | |
98 | long newWindowEndTime = validateWindowEndTime(newWindowStartTime, newWindowStartTime + newDuration); | |
99 | newWindowStartTime = validateWindowStartTime(newWindowStartTime); | |
100 | viewer.updateWindow(newWindowStartTime, newWindowEndTime); | |
101 | } | |
102 | ||
103 | // ------------------------------------------------------------------------ | |
104 | // Helper methods | |
105 | // ------------------------------------------------------------------------ | |
106 | private long validateWindowStartTime(long start) { | |
107 | ITmfChartTimeProvider viewer = getChartViewer(); | |
108 | long realStart = start; | |
109 | ||
110 | long startTime = viewer.getStartTime(); | |
111 | long endTime = viewer.getEndTime(); | |
112 | ||
113 | if (realStart < startTime) { | |
114 | realStart = startTime; | |
115 | } | |
116 | if (realStart > endTime) { | |
117 | realStart = endTime; | |
118 | } | |
119 | return realStart; | |
120 | } | |
121 | ||
122 | private long validateWindowEndTime(long start, long end) { | |
123 | ITmfChartTimeProvider viewer = getChartViewer(); | |
124 | long realEnd = end; | |
125 | long endTime = viewer.getEndTime(); | |
126 | ||
127 | if (realEnd > endTime) { | |
128 | realEnd = endTime; | |
129 | } | |
130 | if (realEnd < start + MIN_WINDOW_SIZE) { | |
131 | realEnd = start + MIN_WINDOW_SIZE; | |
132 | } | |
133 | return realEnd; | |
134 | } | |
135 | } |