1page.title=Buttons
2page.tags=buttons
3@jd:body
4
5<p>
6  Some content is best experienced full screen, like videos, games, image
7  galleries, books, and slides in a presentation. You can engage users more
8  deeply with content in full screen by minimizing visual distraction from app
9  controls and protecting users from escaping the app accidentally.
10</p>
11
12<div style="margin:auto;padding:auto;text-align:center;">
13    <img src="{@docRoot}design/media/fullscreen_landing.png" style="margin:1em auto 2em auto;">
14</div>
15<p>
16  In version 4.4, Android offers two approaches for making your app go full
17  screen: Lean Back and Immersive. In both approaches, all persistent system
18  bars are hidden. The difference between them is how the user brings the bars
19  back into view.
20</p>
21
22<div class="cols">
23  <div class="col-6">
24    <h4>Lean Back</h4>
25    <p>Touch the screen anywhere to bring back system bars. </p>
26    <img src="{@docRoot}design/media/fullscreen_leanback.png" style="width:311px;">
27  </div>
28  <div class="col-6">
29    <h4>Immersive</h4>
30    <p>Swipe from the any edge of the screen with a hidden bar to bring back system bars. </p>
31    <img src="{@docRoot}design/media/fullscreen_immersive_swipe_bottom.png" style="width:160px;float:right">
32    <img src="{@docRoot}design/media/fullscreen_immersive_swipe_top.png" style="width:160px">
33  </div>
34</div>
35
36<h2 id="leanback">
37  Lean Back
38</h2>
39
40<p>
41  The Lean Back approach is for full-screen experiences in which users won't be
42  interacting heavily with the screen while consuming content, like while
43  watching a video.
44</p>
45
46<p>
47  In this type of experience, users are leaning back and watching the screen.
48  Then, when they need to bring back the bars, they simply touch anywhere. This
49  gesture is easy and intuitive.
50</p>
51
52    <img src="{@docRoot}design/media/fullscreen_leanback.png" style="width:311px;">
53
54<h2 id="immersive">
55  Immersive
56</h2>
57
58<p>
59  The Immersive approach is mainly intended for apps in which the user will be
60  heavily interacting with the full screen as part of the primary experience.
61  Examples are games, viewing images in a gallery, or reading paginated
62  content, like a book or slides in a presentation.
63</p>
64
65<p>
66  In this type of experience, when users need to bring back the system bars,
67  they swipe from any edge where a system bar is hidden. By requiring this more
68  deliberate gesture, the user's deep engagement with your app won't be
69  interrupted by accidental touches and swipes.
70</p>
71
72<div class="cols">
73  <div class="col-6">
74    <img src="{@docRoot}design/media/fullscreen_immersive_swipe_bottom.png" style="width:160px;float:right">
75    <img src="{@docRoot}design/media/fullscreen_immersive_swipe_top.png" style="width:160px">
76  </div>
77</div>
78
79<p>
80  The user learns about the gesture to bring back the system bars through a
81  message that appears the first time the app goes full screen.
82</p>
83
84<p>
85  If your app has its own controls that aren't needed when a user is immersed
86  in content, make them disappear and reappear in sync with the system bars.
87  This rule also applies to any app-specific gestures you might have for hiding
88  and showing app controls. For example, if touching anywhere on the screen
89  toggles the appearance of an action bar or a palette, then it must also
90  toggle the appearance of system bars.
91</p>
92
93<p>
94  You might be tempted to use this approach just to maximize screen real
95  estate. But be mindful of how often users jump in and out of apps to check
96  notifications, do impromptu searches, and more. This approach will cause
97  users to lose easy access to system navigation, so a little extra space
98  should not be the only benefit they're getting in return.
99</p>
100
101<h2 id="variation_using_edges">
102  Variation: Swiping from edges with bars also affects the app
103</h2>
104
105<p>
106  In the Immersive approach, any time a user swipes from an edge with a system
107  bar, the Android framework takes care of revealing the system bars. Your app
108  won't even be aware that this gesture occurred.
109</p>
110
111<p>
112  But in some apps, the user might occasionally need to swipe from the edge as
113  <strong>part of the primary app experience</strong>. Examples are games and
114  drawing applications.
115</p>
116
117<p>
118  For apps with this requirement, you can use a variation on the Immersive
119  approach: when a user swipes from an edge with a system bar, system bars are
120  shown and the gesture is passed to the app so the app can respond to the
121  gesture.
122</p>
123
124<p>
125  For example, in a drawing app that uses this approach, if a user wants to
126  draw a line that begins at the very edge of the screen, swiping from the edge
127  would reveal the system bars and also start drawing a line that begins at the
128  very edge.
129</p>
130
131<p>
132  In this approach, to minimize disruption while a user is deeply engaged in
133  the app, the system bars are semi-transparent. The bars automatically
134  disappear after a few seconds of no interaction or as soon as the user
135  touches or gestures anywhere outside the system bars.
136</p>
137
138<h2 id="lightsout">What About Lights Out Mode?</h2>
139
140<p>
141  Before Android 4.4, the design guideline was to use Lights Out mode, a mode
142  in which the Action Bar and Status Bar fades away and becomes unavailable
143  after a few seconds of inactivity. The Navigation Bar is still available and
144  responds to touches but appears dimmed.
145</p>
146
147<p>
148  Replace previous implementations of Lights Out mode with the Lean Back or
149  Immersive approaches. Continue to use Lights Out mode for implementations of
150  your app targeted for earlier releases.
151</p>
152