1page.title=Displaying Progress in a Notification 2parent.title=Notifying the User 3parent.link=index.html 4 5trainingnavtop=true 6previous.title=Using Expanded Notification Styles 7previous.link=expanded.html 8 9@jd:body 10 11<div id="tb-wrapper"> 12<div id="tb"> 13 14<!-- table of contents --> 15<h2>This lesson teaches you to</h2> 16<ol> 17 <li><a href="#FixedProgress">Display a Fixed-duration progress Indicator</a></li> 18 <li><a href="#ActivityIndicator">Display a Continuing Activity Indicator</a></li> 19</ol> 20 21<!-- other docs (NOT javadocs) --> 22<h2>You should also read</h2> 23 24<ul> 25 <li> 26 <a href="{@docRoot}guide/topics/ui/notifiers/notifications.html">Notifications</a> API Guide 27 </li> 28 <li> 29 <a href="{@docRoot}guide/components/intents-filters.html"> 30 Intents and Intent Filters 31 </a> 32 </li> 33 <li> 34 <a href="{@docRoot}design/patterns/notifications.html">Notifications</a> Design Guide 35 </li> 36</ul> 37 38 39</div> 40</div> 41 42 43 44<p> 45 Notifications can include an animated progress indicator that shows users the status 46 of an ongoing operation. If you can estimate how long the operation takes and how much of it 47 is complete at any time, use the "determinate" form of the indicator 48 (a progress bar). If you can't estimate the length of the operation, use the 49 "indeterminate" form of the indicator (an activity indicator). 50</p> 51<p> 52 Progress indicators are displayed with the platform's implementation of the 53 {@link android.widget.ProgressBar} class. 54</p> 55<p> 56 To use a progress indicator, call 57 {@link android.support.v4.app.NotificationCompat.Builder#setProgress setProgress()}. The 58 determinate and indeterminate forms are described in the following sections. 59</p> 60<!-- ------------------------------------------------------------------------------------------ --> 61<h2 id="FixedProgress">Display a Fixed-duration Progress Indicator</h2> 62<p> 63 To display a determinate progress bar, add the bar to your notification by calling 64 {@link android.support.v4.app.NotificationCompat.Builder#setProgress 65 setProgress(max, progress, false)} and then issue the notification. 66 The third argument is a boolean that indicates whether the 67 progress bar is indeterminate (<strong>true</strong>) or determinate (<strong>false</strong>). 68 As your operation proceeds, 69 increment <code>progress</code>, and update the notification. At the end of the operation, 70 <code>progress</code> should equal <code>max</code>. A common way to call 71 {@link android.support.v4.app.NotificationCompat.Builder#setProgress setProgress()} 72 is to set <code>max</code> to 100 and then increment <code>progress</code> as a 73 "percent complete" value for the operation. 74</p> 75<p> 76 You can either leave the progress bar showing when the operation is done, or remove it. In 77 either case, remember to update the notification text to show that the operation is complete. 78 To remove the progress bar, call 79 {@link android.support.v4.app.NotificationCompat.Builder#setProgress 80 setProgress(0, 0, false)}. For example: 81</p> 82<pre> 83... 84mNotifyManager = 85 (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE); 86mBuilder = new NotificationCompat.Builder(this); 87mBuilder.setContentTitle("Picture Download") 88 .setContentText("Download in progress") 89 .setSmallIcon(R.drawable.ic_notification); 90// Start a lengthy operation in a background thread 91new Thread( 92 new Runnable() { 93 @Override 94 public void run() { 95 int incr; 96 // Do the "lengthy" operation 20 times 97 for (incr = 0; incr <= 100; incr+=5) { 98 // Sets the progress indicator to a max value, the 99 // current completion percentage, and "determinate" 100 // state 101 mBuilder.setProgress(100, incr, false); 102 // Displays the progress bar for the first time. 103 mNotifyManager.notify(0, mBuilder.build()); 104 // Sleeps the thread, simulating an operation 105 // that takes time 106 try { 107 // Sleep for 5 seconds 108 Thread.sleep(5*1000); 109 } catch (InterruptedException e) { 110 Log.d(TAG, "sleep failure"); 111 } 112 } 113 // When the loop is finished, updates the notification 114 mBuilder.setContentText("Download complete") 115 // Removes the progress bar 116 .setProgress(0,0,false); 117 mNotifyManager.notify(ID, mBuilder.build()); 118 } 119 } 120// Starts the thread by calling the run() method in its Runnable 121).start(); 122</pre> 123<p> 124 The resulting notifications are shown in figure 1. On the left side is a snapshot of the 125 notification during the operation; on the right side is a snapshot of it after the operation 126 has finished. 127</p> 128<img 129 id="figure1" 130 src="{@docRoot}images/ui/notifications/progress_bar_summary.png" 131 height="84" 132 alt="" /> 133<p class="img-caption"> 134<strong>Figure 1.</strong> The progress bar during and after the operation.</p> 135<!-- ------------------------------------------------------------------------------------------ --> 136<h2 id="ActivityIndicator">Display a Continuing Activity Indicator</h2> 137<p> 138 To display a continuing (indeterminate) activity indicator, add it to your notification with 139 {@link android.support.v4.app.NotificationCompat.Builder#setProgress setProgress(0, 0, true)} 140 and issue the notification. The first two arguments are ignored, and the third argument 141 declares that the indicator is indeterminate. The result is an indicator 142 that has the same style as a progress bar, except that its animation is ongoing. 143</p> 144<p> 145 Issue the notification at the beginning of the operation. The animation will run until you 146 modify your notification. When the operation is done, call 147 {@link android.support.v4.app.NotificationCompat.Builder#setProgress 148 setProgress(0, 0, false)} and then update the notification to remove the activity indicator. 149 Always do this; otherwise, the animation will run even when the operation is complete. Also 150 remember to change the notification text to indicate that the operation is complete. 151</p> 152<p> 153 To see how continuing activity indicators work, refer to the preceding snippet. Locate the following lines: 154</p> 155<pre> 156// Sets the progress indicator to a max value, the current completion 157// percentage, and "determinate" state 158mBuilder.setProgress(100, incr, false); 159// Issues the notification 160mNotifyManager.notify(0, mBuilder.build()); 161</pre> 162<p> 163 Replace the lines you've found with the following lines. Notice that the third parameter 164 in the {@link android.support.v4.app.NotificationCompat.Builder#setProgress setProgress()} 165 call is set to {@code true} to indicate that the progress bar is 166 indeterminate: 167</p> 168<pre> 169 // Sets an activity indicator for an operation of indeterminate length 170mBuilder.setProgress(0, 0, true); 171// Issues the notification 172mNotifyManager.notify(0, mBuilder.build()); 173</pre> 174<p> 175 The resulting indicator is shown in figure 2: 176</p> 177<img 178 id="figure2" 179 src="{@docRoot}images/ui/notifications/activity_indicator.png" 180 height="99" 181 alt="" /> 182<p class="img-caption"><strong>Figure 2.</strong> An ongoing activity indicator.</p> 183
