Adding instructions on how to build and run ExoPlayer demo apps

Issue:#7338
PiperOrigin-RevId: 312470913

demos/README.md

@@ -2,3 +2,24 @@
 
 
 This directory contains applications that demonstrate how to use ExoPlayer.
 This directory contains applications that demonstrate how to use ExoPlayer.
 Browse the individual demos and their READMEs to learn more.
 Browse the individual demos and their READMEs to learn more.
+
+## Running a demo ##
+
+### From Android Studio ###
+
+* File -> New -> Import Project -> Specify the root ExoPlayer folder.
+* Choose the demo from the run configuration dropdown list.
+* Click Run.
+
+### Using gradle from the command line: ###
+
+* Open a Terminal window at the root ExoPlayer folder.
+* Run `./gradlew projects` to show all projects. Demo projects start with `demo`.
+* Run `./gradlew :<demo name>:tasks` to view the list of available tasks for
+the demo project. Choose an install option from the `Install tasks` section.
+* Run `./gradlew :<demo name>:<install task>`.
+
+**Example**:
+
+`./gradlew :demo:installNoExtensionsDebug` installs the main ExoPlayer demo app
+ in debug mode with no extensions.

demos/cast/README.md

@@ -2,3 +2,6 @@
 
 
 This folder contains a demo application that showcases ExoPlayer integration
 This folder contains a demo application that showcases ExoPlayer integration
 with Google Cast.
 with Google Cast.
+
+Please see the [demos README](../README.md) for instructions on how to build and
+run this demo.

demos/gl/README.md

@@ -8,4 +8,7 @@ drawn using an Android canvas, and includes the current frame's presentation
 timestamp, to show how to get the timestamp of the frame currently in the
 timestamp, to show how to get the timestamp of the frame currently in the
 off-screen surface texture.
 off-screen surface texture.
 
 
+Please see the [demos README](../README.md) for instructions on how to build and
+run this demo.
+
 [GLSurfaceView]: https://developer.android.com/reference/android/opengl/GLSurfaceView
 [GLSurfaceView]: https://developer.android.com/reference/android/opengl/GLSurfaceView

demos/main/README.md

@@ -3,3 +3,6 @@
 This is the main ExoPlayer demo application. It uses ExoPlayer to play a number
 This is the main ExoPlayer demo application. It uses ExoPlayer to play a number
 of test streams. It can be used as a starting point or reference project when
 of test streams. It can be used as a starting point or reference project when
 developing other applications that make use of the ExoPlayer library.
 developing other applications that make use of the ExoPlayer library.
+
+Please see the [demos README](../README.md) for instructions on how to build and
+run this demo.

demos/surface/README.md

@@ -18,4 +18,7 @@ called, and because you can move output off-screen easily (`setOutputSurface`
 can't take a `null` surface, so the player has to use a `DummySurface`, which
 can't take a `null` surface, so the player has to use a `DummySurface`, which
 doesn't handle protected output on all devices).
 doesn't handle protected output on all devices).
 
 
+Please see the [demos README](../README.md) for instructions on how to build and
+run this demo.
+
 [SurfaceControl]: https://developer.android.com/reference/android/view/SurfaceControl
 [SurfaceControl]: https://developer.android.com/reference/android/view/SurfaceControl