README

AudioFocusGrabber: a Tool for Testing Audio Focus Handling in Apps

A simple app used to test audio focus handling in apps, especially MediaSession in Chrome. You can perform audio gain/abandon actions, in order to simulate a short ping from an SMS or email, or permanent audio focus gain from other media player apps.

Setup

1: Build and install the AudioFocusGrabber app

ninja -C out/Debug audio_focus_grabber_apk
adb install -r out/Debug/apks/AudioFocusGrabber.apk

2: Simulate audio focus actions

You can simulate audio focus actions using the UI, the notification bar or through adb shell. There are three kinds of audio focus actions, corresponding to:

AudioManager.AUDIOFOCUS_GAIN
AudioManager.AUDIOFOCUS_TRANSIENT
AudioManager.AUDIOFOCUS_TRANSIENT_MAY_DUCK

2.1: Controlling from the UI

From the UI, there are three buttons for the three actions. Just click it, and AudioFocusGrabber will perform the audio focus action, and play a ping sound.

However in this way, the app must be in background.

2.2: Controlling from the notification

You can also start a notification from the UI, and then you can make controls from the notification.

In this way, the app must be in background or losed window focus.

2.3 Controlling from the `adb` shell

From the adb shell, which you can do it even if the AudioFocusGrabber is not in foreground. You may use the following three commands:

adb shell am startservice -a AUDIO_FOCUS_GRABBER_GAIN
adb shell am startservice -a AUDIO_FOCUS_GRABBER_TRANSIENT_PAUSE
adb shell am startservice -a AUDIO_FOCUS_GRABBER_TRANSIENT_DUCK

In this way, the app may be in the foreground, in the background or losed window focus.