1page.title=Hiding the Status Bar
2
3trainingnavtop=true
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5@jd:body
6
7<div id="tb-wrapper">
8<div id="tb">
9
10<!-- table of contents -->
11<h2>This lesson teaches you to</h2>
12<ol>
13  <li><a href="#40">Hide the Status Bar on Android 4.0 and Lower</a></li>
14  <li><a href="#41">Hide the Status Bar on Android 4.1 and Higher</a></li>
15  <li><a href="#behind">Make Content Appear Behind the Status Bar</a></li>
16</ol>
17
18<!-- other docs (NOT javadocs) -->
19<h2>You should also read</h2>
20
21<ul>
22    <li>
23        <a href="{@docRoot}training/appbar/index.html">Adding the App Bar</a>
24    </li>
25    <li>
26        <a href="{@docRoot}design/index.html">
27        Android Design Guide
28        </a>
29    </li>
30</ul>
31
32<h2>Try it out</h2>
33
34<div class="download-box">
35  <a href="{@docRoot}samples/ImmersiveMode/index.html"
36class="button">Get the sample</a>
37 <p class="filename">ImmersiveMode sample</p>
38</div>
39
40</div>
41</div>
42
43<p>
44    This lesson describes how to hide the status bar on different versions of
45    Android. Hiding the status bar (and optionally, the navigation bar) lets the
46    content use more of the display space, thereby providing a more immersive user experience.
47
48</p>
49
50<p>
51 Figure 1 shows an app with a visible status bar:
52</p>
53
54<img src="{@docRoot}images/training/status_bar_show.png"
55  alt="system bars">
56<p class="img-caption"><strong>Figure 1.</strong> Visible status bar.</p>
57
58<p>
59 Figure 2 shows an app with a hidden status bar. Note that the action bar is hidden too.
60 You should never show the action bar without the status bar.
61</p>
62
63<img src="{@docRoot}images/training/status_bar_hide.png"
64  alt="system bars">
65<p class="img-caption"><strong>Figure 2.</strong> Hidden status bar.</p>
66
67<h2 id="40">Hide the Status Bar on Android 4.0 and Lower</h2>
68
69<p>You can hide the status bar on Android 4.0 (API level 14) and lower by setting
70{@link android.view.WindowManager} flags. You can do this programmatically or by
71setting an activity theme in your app's manifest file. Setting an activity theme in your app's
72manifest file is the preferred approach if the status bar should always remain
73hidden in your app (though strictly speaking, you could programmatically override the
74theme if you wanted to). For example:</p>
75
76<pre>
77&lt;application
78    ...
79    android:theme=&quot;@android:style/Theme.Holo.NoActionBar.Fullscreen&quot; &gt;
80    ...
81&lt;/application&gt;
82</pre>
83
84<p>The advantages of using an activity theme are as follows:</p>
85
86<ul>
87<li>It's easier to maintain and less error-prone than setting a flag programmatically.</li>
88<li>It results in smoother UI transitions, because the system has the information it needs
89to render your UI before instantiating your app's main activity.</li>
90</ul>
91
92<p>
93Alternatively, you can programmatically set {@link android.view.WindowManager} flags.
94This approach makes it easier to hide and show the status bar as the user interacts with
95your app:</p>
96
97<pre>public class MainActivity extends Activity {
98
99    &#64;Override
100    protected void onCreate(Bundle savedInstanceState) {
101        super.onCreate(savedInstanceState);
102        // If the Android version is lower than Jellybean, use this call to hide
103        // the status bar.
104        if (Build.VERSION.SDK_INT &lt; 16) {
105            getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
106                    WindowManager.LayoutParams.FLAG_FULLSCREEN);
107        }
108        setContentView(R.layout.activity_main);
109    }
110    ...
111}
112</pre>
113
114<p>When you set {@link android.view.WindowManager} flags (whether through an activity theme or
115programmatically), the flags remain in effect unless your app clears them.</p>
116
117<p>You can use
118{@link android.view.WindowManager.LayoutParams#FLAG_LAYOUT_IN_SCREEN}
119to set  your activity layout to use the same screen area that's available when you've enabled
120{@link android.view.WindowManager.LayoutParams#FLAG_FULLSCREEN}. This prevents your
121content from resizing when the status bar hides and shows.</p>
122
123
124<h2 id="41">Hide the Status Bar on Android 4.1 and Higher</h2>
125
126<p>You can hide the status bar on Android 4.1 (API level 16) and higher by
127using {@link android.view.View#setSystemUiVisibility setSystemUiVisibility()}.
128{@link android.view.View#setSystemUiVisibility setSystemUiVisibility()} sets UI flags at
129the individual view level; these settings are aggregated to the window level. Using
130{@link android.view.View#setSystemUiVisibility setSystemUiVisibility()} to set UI flags
131gives you more granular control over the system bars than using
132{@link android.view.WindowManager} flags. This snippet hides the status bar:</p>
133
134<pre>View decorView = getWindow().getDecorView();
135// Hide the status bar.
136int uiOptions = View.SYSTEM_UI_FLAG_FULLSCREEN;
137decorView.setSystemUiVisibility(uiOptions);
138// Remember that you should never show the action bar if the
139// status bar is hidden, so hide that too if necessary.
140ActionBar actionBar = getActionBar();
141actionBar.hide();
142</pre>
143
144<p>Note the following:</p>
145
146<ul>
147<li>Once UI flags have been cleared (for example, by navigating away from the
148activity), your app needs to reset them if you want to hide the bars again.
149See <a href="visibility.html">Responding to UI Visibility Changes</a> for a
150discussion of how to listen for UI visibility changes so that your app can
151respond accordingly.</li>
152
153<li>Where you set the UI flags makes a difference. If you hide the system bars in your activity's
154 {@link android.app.Activity#onCreate onCreate()} method and the user presses Home, the system bars will
155 reappear. When the user reopens the activity, {@link android.app.Activity#onCreate onCreate()}
156won't get called, so the system bars will remain visible. If you want system UI changes to
157persist as the user navigates in and out of your activity, set UI flags in
158{@link android.app.Activity#onResume onResume()}
159or {@link android.view.Window.Callback#onWindowFocusChanged onWindowFocusChanged()}.</li>
160
161  <li>The method {@link android.view.View#setSystemUiVisibility setSystemUiVisibility()}
162  only has an effect if the view you call it from is visible.</li>
163
164  <li>Navigating away from the view causes flags
165  set with {@link android.view.View#setSystemUiVisibility setSystemUiVisibility()}
166  to be cleared.</li>
167</ul>
168 </p>
169
170 <h2 id="behind">Make Content Appear Behind the Status Bar</h2>
171<p>On Android 4.1 and higher, you can set your application's content to appear behind
172the status bar, so that the content doesn't resize as the status bar hides and shows.
173To do this, use
174{@link android.view.View#SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN}.
175You may also need to use
176{@link android.view.View#SYSTEM_UI_FLAG_LAYOUT_STABLE} to help your app maintain a
177stable layout.</p>
178
179<p>When you use this approach, it becomes your responsibility to ensure that critical parts
180of your app's UI (for example, the built-in controls in a Maps application) don't end up
181getting covered by system bars. This could make your app unusable. In most cases you can
182handle this by adding the {@code android:fitsSystemWindows} attribute to your XML layout file, set to
183{@code true}. This adjusts the padding of the parent {@link android.view.ViewGroup}
184to leave space for the system windows. This is sufficient for most applications.</p>
185
186<p>In some cases, however, you may need to modify the default padding to get the desired
187layout for your app. To directly manipulate how your
188content lays out relative to the system bars (which occupy a space known as the window's
189"content insets"), override {@link android.view.View#fitSystemWindows fitSystemWindows(Rect insets)}.
190The {@link android.view.View#fitSystemWindows fitSystemWindows()} method is called by the
191view hierarchy when the content insets for a window have changed, to allow the window to
192adjust its content accordingly. By overriding this method you can handle the
193insets (and hence your app's layout) however you want. </p>
194