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For example, if your app requires portrait orientation, you should declare<uses-feature android:name="android.hardware.screen.portrait"/> so that only devicesthat support portrait orientation (whether always or by user choice) can install your
app. If yourapplication supports both orientations, then you don't need to declare either.

Both orientations are assumed not required, by default, so your app may be installedon devices that support one or both orientations. However, if any of your activities request thatthey run in a specific orientation, using the

android:screenOrientation attribute, then this also declares that the application requires thatorientation. For example, if you declare

android:screenOrientation with either "landscape",
"reverseLandscape", or"sensorLandscape", then your application will be available only to devices that supportlandscape orientation. As a best practice, you should still declare your requirement for thisorientation using a
<uses-feature> element. If you declare an orientation for youractivity using

android:screenOrientation, but don't actually require it, you can disable therequirement by declaring the orientation with a
<uses-feature> element and includeandroid:required="false".

For backwards compatibility, any device running a platform version that supports only APIlevel 12 or lower is assumed to support both landscape and portrait.

When declared as required, this indicates that the application is compatible with a deviceonly if it offers an emulated touchscreen ("fake touch" interface), or better. A device that offersa fake touch interface provides a user input system that emulates
a subset of touchscreencapabilities. For example, a mouse or remote control that drives an on-screen cursor provides a faketouch interface. If your application requires basic point and click interaction (in otherwords, it won't work with
only a d-pad controller), you should declare this feature.Because this is the minimum level of touch interaction, your app will also be compatible withdevices that offer more complex touch interfaces.

Note: Because applications require the android.hardware.touchscreen feature by default, if you want your application to be available todevices that provide a fake touch interface, you must also explicitly declare
that a touch screen isnot required by declaring <uses-featureandroid:name="android.hardware.touchscreen"
android:required="false"/>

When declared as required, this indicates that the application is compatible with a deviceonly if it supports touch emulation for events that supports distinct tracking of two or morefingers, or better.

Unlike the distinct multitouch defined by android.hardware.touchscreen.multitouch.distinct, input devices that support distinct multi-touchwith a fake touch interface will not support all two-finger gestures, because the input isbeing transformed
to cursor movement on the screen. That is, single finger gestures on such a devicemove a cursor; two-finger swipes will result in single-finger touch events; other two-fingergestures will result in the corresponding two-finger touch event. An example device
that supportsdistinct multi-touch with a fake touch interface is one that provides a trackpad for cursor movementwhich also supports two or more fingers.

When declared as required, this indicates that the application is compatible with a deviceonly if it supports touch emulation for events that supports distinct tracking of five or morefingers.

Unlike the distinct multitouch defined by android.hardware.touchscreen.multitouch.jazzhand, input devices that support jazzhand multi-touchwith a fake touch interface will not support all five-finger gestures, because the input is beingtransformed
to cursor movement on the screen. That is, single finger gestures on such a device movea cursor; multi-finger gestures will result in single-finger touch events; other multi-fingergestures will result in the corresponding multi-finger touch event. An example
device that supportsdistinct multi-touch with a fake touch interface is one that provides a trackpad for cursor movementwhich also supports five or more fingers.

By default, your application requires this. As such, your application is notavailable to devices that provide only an emulated touch interface ("fake touch"), by default. Ifyou want your application available to devices that provide a fake touch
interface (or even devicesthat provide only a d-pad controller), you must explicitly declare that a touch screen is notrequired, by declaring
android.hardware.touchscreen with android:required="false".You should do so even if your application uses—but does not
require—a realtouch screen interface.

If your application does require a touch interface (in order to perform touchgestures such as a fling), then you don't need to do anything, because this is required by default.However, it's best if you explicitly declare all features used by your
application, so you shouldstill declare this if your app uses it.

If you require more complex touch interaction, such as multi-finger gestures, youshould declare the advanced touch screen features below.

(See
Special handling for Bluetooth feature for details.)