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Java > Open Source Codes > org > eclipse > jface > dialogs > ProgressIndicator


1 /*******************************************************************************
2  * Copyright (c) 2000, 2006 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.dialogs;
12
13 import org.eclipse.swt.SWT;
14 import org.eclipse.swt.custom.StackLayout;
15 import org.eclipse.swt.widgets.Composite;
16 import org.eclipse.swt.widgets.ProgressBar;
17
18 /**
19  * A control for showing progress feedback for a long running operation. This
20  * control supports both determinate and indeterminate SWT progress bars. For
21  * indeterminate progress, we don't have to know the total amount of work in
22  * advance and no <code>worked</code> method needs to be called.
23  */
24 public class ProgressIndicator extends Composite {
25     private final static int PROGRESS_MAX = 1000; // value to use for max in
26
27     // progress bar
28 private boolean animated = true;
29
30     private StackLayout layout;
31
32     private ProgressBar determinateProgressBar;
33
34     private ProgressBar indeterminateProgressBar;
35
36     private double totalWork;
37
38     private double sumWorked;
39
40     /**
41      * Create a ProgressIndicator as a child under the given parent.
42      *
43      * @param parent
44      * The widgets parent
45      */
46     public ProgressIndicator(Composite parent) {
47         super(parent, SWT.NULL);
48         determinateProgressBar = new ProgressBar(this, SWT.HORIZONTAL);
49         indeterminateProgressBar = new ProgressBar(this, SWT.HORIZONTAL
50                 | SWT.INDETERMINATE);
51         layout = new StackLayout();
52         setLayout(layout);
53     }
54
55     /**
56      * Initialize the progress bar to be animated.
57      */
58     public void beginAnimatedTask() {
59         done();
60         layout.topControl = indeterminateProgressBar;
61         layout();
62         animated = true;
63     }
64
65     /**
66      * Initialize the progress bar.
67      *
68      * @param max
69      * The maximum value.
70      */
71     public void beginTask(int max) {
72         done();
73         this.totalWork = max;
74         this.sumWorked = 0;
75         determinateProgressBar.setMinimum(0);
76         determinateProgressBar.setMaximum(PROGRESS_MAX);
77         determinateProgressBar.setSelection(0);
78         layout.topControl = determinateProgressBar;
79         layout();
80         animated = false;
81     }
82
83     /**
84      * Progress is done.
85      */
86     public void done() {
87         if (!animated) {
88             determinateProgressBar.setMinimum(0);
89             determinateProgressBar.setMaximum(0);
90             determinateProgressBar.setSelection(0);
91         }
92         layout.topControl = null;
93         layout();
94     }
95
96     /**
97      * Moves the progress indicator to the end.
98      */
99     public void sendRemainingWork() {
100         worked(totalWork - sumWorked);
101     }
102
103     /**
104      * Moves the progress indicator by the given amount of work units
105      * @param work the amount of work to increment by.
106      */
107     public void worked(double work) {
108         if (work == 0 || animated) {
109             return;
110         }
111         sumWorked += work;
112         if (sumWorked > totalWork) {
113             sumWorked = totalWork;
114         }
115         if (sumWorked < 0) {
116             sumWorked = 0;
117         }
118         int value = (int) (sumWorked / totalWork * PROGRESS_MAX);
119         if (determinateProgressBar.getSelection() < value) {
120             determinateProgressBar.setSelection(value);
121         }
122     }
123 }
124
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