KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > eclipse > jface > viewers > deferred > FastProgressReporter


1 /*******************************************************************************
2  * Copyright (c) 2004, 2005 IBM Corporation and others.
3  * All rights reserved. This program and the accompanying materials
4  * are made available under the terms of the Eclipse Public License v1.0
5  * which accompanies this distribution, and is available at
6  * http://www.eclipse.org/legal/epl-v10.html
7  *
8  * Contributors:
9  * IBM Corporation - initial API and implementation
10  *******************************************************************************/
11 package org.eclipse.jface.viewers.deferred;
12
13 import org.eclipse.core.runtime.IProgressMonitor;
14
15 /**
16  * A more efficient alternative to an IProgressMonitor. In particular, the implementation
17  * is designed to make isCanceled() run as efficiently as possible. Currently package-visible
18  * because the implementation is incomplete.
19  *
20  * @since 3.1
21  */
22 final class FastProgressReporter {
23     private IProgressMonitor monitor;
24     private volatile boolean canceled = false;
25     private int cancelCheck = 0;
26 // private String taskName;
27 //
28 // private int taskDepth = 0;
29 // private int subTaskSize = 1;
30 // private int totalWork = 1;
31 // private int parentWork = 1;
32 // private int monitorUnitsRemaining;
33
34     private static int CANCEL_CHECK_PERIOD = 40;
35     
36     /**
37      * Constructs a null FastProgressReporter
38      */
39     public FastProgressReporter() {
40     }
41     
42     /**
43      * Constructs a FastProgressReporter that wraps the given progress monitor
44      *
45      * @param monitor the monitor to wrap
46      * @param totalProgress the total progress to be reported
47      */
48     public FastProgressReporter(IProgressMonitor monitor, int totalProgress) {
49         this.monitor = monitor;
50         //monitorUnitsRemaining = totalProgress;
51 canceled = monitor.isCanceled();
52     }
53     
54 // /**
55 // * Every call to beginTask must have a corresponding call to endTask, with the
56 // * same argument.
57 // *
58 // * @param totalWork
59 // * @since 3.1
60 // */
61 // public void beginTask(int totalWork) {
62 //
63 // if (monitor == null) {
64 // return;
65 // }
66 //
67 // taskDepth++;
68 //
69 // if (totalWork == 0) {
70 // return;
71 // }
72 //
73 // this.totalWork *= totalWork;
74 // }
75 //
76 // public void beginSubTask(int subTaskWork) {
77 // subTaskSize *= subTaskWork;
78 // }
79 //
80 // public void endSubTask(int subTaskWork) {
81 // subTaskSize /= subTaskWork;
82 // }
83 //
84 // public void worked(int amount) {
85 // amount *= subTaskSize;
86 //
87 // if (amount > totalWork) {
88 // amount = totalWork;
89 // }
90 //
91 // int consumed = monitorUnitsRemaining * amount / totalWork;
92 //
93 // if (consumed > 0) {
94 // monitor.worked(consumed);
95 // monitorUnitsRemaining -= consumed;
96 // }
97 // totalWork -= amount;
98 // }
99 //
100 // public void endTask(int totalWork) {
101 // taskDepth--;
102 //
103 // if (taskDepth == 0) {
104 // if (monitor != null && monitorUnitsRemaining > 0) {
105 // monitor.worked(monitorUnitsRemaining);
106 // }
107 // }
108 //
109 // if (totalWork == 0) {
110 // return;
111 // }
112 //
113 // this.totalWork /= totalWork;
114 //
115 // }
116
117     /**
118      * Return whether the progress monitor has been canceled.
119      *
120      * @return <code>true</code> if the monitor has been cancelled, <code>false</code> otherwise.
121      */
122     public boolean isCanceled() {
123         if (monitor == null) {
124             return canceled;
125         }
126         
127         cancelCheck++;
128         if (cancelCheck > CANCEL_CHECK_PERIOD) {
129             canceled = monitor.isCanceled();
130             cancelCheck = 0;
131         }
132         return canceled;
133     }
134     
135     /**
136      * Cancel the progress monitor.
137      */
138     public void cancel() {
139         canceled = true;
140         
141         if (monitor == null) {
142             return;
143         }
144         monitor.setCanceled(true);
145     }
146 }
147
Popular Tags