001 /* ProgressMonitor.java --
002 Copyright (C) 2002, 2004, 2005, 2006, Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
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017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
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033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038 package javax.swing;
039
040 import java.awt.Component;
041 import java.awt.event.ActionEvent;
042 import java.awt.event.ActionListener;
043
044 import javax.accessibility.AccessibleContext;
045
046 /**
047 * <p>Using this class you can easily monitor tasks where you cannot
048 * estimate the duration exactly.</p>
049 *
050 * <p>A ProgressMonitor instance waits until the first time setProgress
051 * is called. When <code>millisToDecideToPopup</code> time elapsed the
052 * instance estimates the duration until the whole operation is completed.
053 * If this duration exceeds <code>millisToPopup</code> a non-modal dialog
054 * with a message and a progress bar is shown.</p>
055 *
056 * <p>The value of <code>millisToDecideToPopup</code> defaults to
057 * <code>500</code> and <code>millisToPopup</code> to
058 * <code>2000</code>.</p>
059 *
060 * @author Andrew Selkirk
061 * @author Robert Schuster (robertschuster@fsfe.org)
062 * @since 1.2
063 * @status updated to 1.2
064 */
065 public class ProgressMonitor
066 {
067
068 /**
069 * The accessible content for this component
070 */
071 protected AccessibleContext accessibleContext;
072
073 /**
074 * parentComponent
075 */
076 Component component;
077
078 /**
079 * note
080 */
081 String note;
082
083 /**
084 * message
085 */
086 Object message;
087
088 /**
089 * millisToDecideToPopup
090 */
091 int millisToDecideToPopup = 500;
092
093 /**
094 * millisToPopup
095 */
096 int millisToPopup = 2000;
097
098 int min, max, progress;
099
100 JProgressBar progressBar;
101
102 JLabel noteLabel;
103
104 JDialog progressDialog;
105
106 Timer timer;
107
108 boolean canceled;
109
110 /**
111 * Creates a new <code>ProgressMonitor</code> instance. This is used to
112 * monitor a task and pops up a dialog if the task is taking a long time to
113 * run.
114 *
115 * @param component The parent component of the progress dialog or
116 * <code>null</code>.
117 * @param message A constant message object which works in the way it does
118 * in {@link JOptionPane}.
119 * @param note A string message which can be changed while the operation goes
120 * on.
121 * @param minimum The minimum value for the operation (start value).
122 * @param maximum The maximum value for the operation (end value).
123 */
124 public ProgressMonitor(Component component, Object message,
125 String note, int minimum, int maximum)
126 {
127
128 // Set data.
129 this.component = component;
130 this.message = message;
131 this.note = note;
132
133 min = minimum;
134 max = maximum;
135 }
136
137 /**
138 * <p>Hides the dialog and stops any measurements.</p>
139 *
140 * <p>Has no effect when <code>setProgress</code> is not at least
141 * called once.</p>
142 */
143 public void close()
144 {
145 if (progressDialog != null)
146 {
147 progressDialog.setVisible(false);
148 }
149
150 if (timer != null)
151 {
152 timer.stop();
153 timer = null;
154 }
155 }
156
157 /**
158 * <p>Updates the progress value.</p>
159 *
160 * <p>When called for the first time this initializes a timer
161 * which decides after <code>millisToDecideToPopup</code> time
162 * whether to show a progress dialog or not.</p>
163 *
164 * <p>If the progress value equals or exceeds the maximum
165 * value the progress dialog is closed automatically.</p>
166 *
167 * @param progress New progress value.
168 */
169 public void setProgress(int progress)
170 {
171 this.progress = progress;
172
173 // Initializes and starts a timer with a task
174 // which measures the duration and displays
175 // a progress dialog if neccessary.
176 if (timer == null && progressDialog == null)
177 {
178 timer = new Timer(25, null);
179 timer.addActionListener(new TimerListener());
180 timer.start();
181 }
182
183 // Cancels timer and hides progress dialog if the
184 // maximum value is reached.
185 if (progressBar != null && this.progress >= progressBar.getMaximum())
186 {
187 // The reason for using progressBar.getMaximum() instead of max is that
188 // we want to prevent that changes to the value have any effect after the
189 // progress dialog is visible (This is how the JDK behaves.).
190 close();
191 }
192
193 }
194
195 /**
196 * Returns the minimum or start value of the operation.
197 *
198 * @return Minimum or start value of the operation.
199 */
200 public int getMinimum()
201 {
202 return min;
203 }
204
205 /**
206 * <p>Use this method to set the minimum or start value of
207 * your operation.</p>
208 *
209 * <p>For typical application like copy operation this will be
210 * zero.</p>
211 *
212 * <p>Keep in mind that changing this value after the progress
213 * dialog is made visible has no effect upon the progress bar.</p>
214 *
215 * @param minimum The new minimum value.
216 */
217 public void setMinimum(int minimum)
218 {
219 min = minimum;
220 }
221
222 /**
223 * Return the maximum or end value of your operation.
224 *
225 * @return Maximum or end value.
226 */
227 public int getMaximum()
228 {
229 return max;
230 }
231
232 /**
233 * <p>Sets the maximum or end value of the operation to the
234 * given integer.</p>
235 *
236 * @param maximum
237 */
238 public void setMaximum(int maximum)
239 {
240 max = maximum;
241 }
242
243 /**
244 * Returns whether the user canceled the operation.
245 *
246 * @return Whether the operation was canceled.
247 */
248 public boolean isCanceled()
249 {
250 // The value is predefined to false
251 // and changes only when the user clicks
252 // the cancel button in the progress dialog.
253 return canceled;
254 }
255
256 /**
257 * Returns the amount of milliseconds to wait
258 * until the ProgressMonitor should decide whether
259 * a progress dialog is to be shown or not.
260 *
261 * @return The duration in milliseconds.
262 */
263 public int getMillisToDecideToPopup()
264 {
265 return millisToDecideToPopup;
266 }
267
268 /**
269 * Sets the amount of milliseconds to wait until the
270 * ProgressMonitor should decide whether a progress dialog
271 * is to be shown or not.
272 *
273 * <p>This method has no effect when the progress dialog
274 * is already visible.</p>
275 *
276 * @param time The duration in milliseconds.
277 */
278 public void setMillisToDecideToPopup(int time)
279 {
280 millisToDecideToPopup = time;
281 }
282
283 /**
284 * Returns the number of milliseconds to wait before displaying the progress
285 * dialog. The default value is 2000.
286 *
287 * @return The number of milliseconds.
288 *
289 * @see #setMillisToPopup(int)
290 */
291 public int getMillisToPopup()
292 {
293 return millisToPopup;
294 }
295
296 /**
297 * Sets the number of milliseconds to wait before displaying the progress
298 * dialog.
299 *
300 * @param time the number of milliseconds.
301 *
302 * @see #getMillisToPopup()
303 */
304 public void setMillisToPopup(int time)
305 {
306 millisToPopup = time;
307 }
308
309 /**
310 * Returns a message which is shown in the progress dialog.
311 *
312 * @return The changeable message visible in the progress dialog.
313 */
314 public String getNote()
315 {
316 return note;
317 }
318
319 /**
320 * <p>Set the message shown in the progess dialog.</p>
321 *
322 * <p>Changing the note while the progress dialog is visible
323 * is possible.</p>
324 *
325 * @param note A message shown in the progress dialog.
326 */
327 public void setNote(String note)
328 {
329 if (noteLabel != null)
330 {
331 noteLabel.setText(note);
332 }
333 else
334 {
335 this.note = note;
336 }
337 }
338
339 /**
340 * Internal method that creates the progress dialog.
341 */
342 void createDialog()
343 {
344 // If there is no note we suppress the generation of the
345 // label.
346 Object[] tmp = (note == null) ?
347 new Object[]
348 {
349 message,
350 progressBar = new JProgressBar(min, max)
351 }
352 :
353 new Object[]
354 {
355 message,
356 noteLabel = new JLabel(note),
357 progressBar = new JProgressBar(min, max)
358 };
359
360 JOptionPane pane = new JOptionPane(tmp, JOptionPane.INFORMATION_MESSAGE);
361
362 // FIXME: Internationalize the button
363 JButton cancelButton = new JButton("Cancel");
364 cancelButton.addActionListener(new ActionListener()
365 {
366 public void actionPerformed(ActionEvent ae)
367 {
368 canceled = true;
369 }
370 });
371
372 pane.setOptions(new Object[] { cancelButton });
373
374 // FIXME: Internationalize the title
375 progressDialog = pane.createDialog(component, "Progress ...");
376 progressDialog.setModal(false);
377 progressDialog.setResizable(true);
378
379 progressDialog.pack();
380 progressDialog.setVisible(true);
381
382 }
383
384 /** An ActionListener implementation which does the measurements
385 * and estimations of the ProgressMonitor.
386 */
387 class TimerListener implements ActionListener
388 {
389 long timestamp;
390
391 int lastProgress;
392
393 boolean first = true;
394
395 TimerListener()
396 {
397 timestamp = System.currentTimeMillis();
398 }
399
400 public void actionPerformed(ActionEvent ae)
401 {
402 long now = System.currentTimeMillis();
403
404 if (first)
405 {
406 if ((now - timestamp) > millisToDecideToPopup)
407 {
408 first = false;
409
410
411 long expected = (progress - min == 0) ?
412 (now - timestamp) * (max - min) :
413 (now - timestamp) * (max - min) / (progress - min);
414
415 if (expected > millisToPopup)
416 {
417 createDialog();
418 }
419 }
420 else
421 {
422 // We have not waited long enough to make a decision,
423 // so return and try again when the timer is invoked.
424 return;
425 }
426 }
427 else if (progressDialog != null)
428 {
429 // The progress dialog is being displayed. We now calculate
430 // whether setting the progress bar to the current progress
431 // value would result in a visual difference.
432 int delta = progress - progressBar.getValue();
433
434 if ((delta * progressBar.getWidth() / (max - min)) > 0)
435 {
436 // At least one pixel would change.
437 progressBar.setValue(progress);
438 }
439 }
440 else
441 {
442 // No dialog necessary
443 timer.stop();
444 timer = null;
445 }
446
447 timestamp = now;
448 }
449 }
450
451 /**
452 * Gets the accessible context.
453 *
454 * @return the accessible context.
455 */
456 public AccessibleContext getAccessibleContext()
457 {
458 return accessibleContext;
459 }
460 }