Call the hardware back button programmatically?

Question

I know that one can overwrite the Back Button functionality in Android, but I was wondering if there was a method or anything I could call that would functionally do the same thing as pressing the hardware button.

Answer 1

You can send the back button press to the system like this

this.dispatchKeyEvent(new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_BACK)); 

Or you can override the back button press and call

finish();

on your Activity. That basically does the same thing as the generic back button.

Answer 2

Just call this.onBackPressed(); in Activity.

Answer 3

If you want just "press" hardware button, create service extended from AccessibilityService:

class ExampleAccessService:AccessibilityService() {
    override fun onInterrupt() {
    }

    override fun onAccessibilityEvent(event: AccessibilityEvent?) {
    }
    
    fun doAction(){
        performGlobalAction(GLOBAL_ACTION_RECENTS)
//        performGlobalAction(GLOBAL_ACTION_BACK)
//        performGlobalAction(GLOBAL_ACTION_HOME)
//        performGlobalAction(GLOBAL_ACTION_NOTIFICATIONS)
//        performGlobalAction(GLOBAL_ACTION_POWER_DIALOG)
//        performGlobalAction(GLOBAL_ACTION_QUICK_SETTINGS)
//        performGlobalAction(GLOBAL_ACTION_TOGGLE_SPLIT_SCREEN)
    }
}

Call doAction() where you want action

Add to Manifest:

<application
...
    <service
        android:name=".ExampleAccessService"
        android:permission="android.permission.BIND_ACCESSIBILITY_SERVICE"
        android:label="Name of servise" // it will be viewed in Settings->Accessibility->Services
        android:enabled="true"
        android:exported="false" >
        <intent-filter>
            <action android:name="android.accessibilityservice.AccessibilityService"/>
        </intent-filter>
        <meta-data
            android:name="android.accessibilityservice"
            android:resource="@xml/accessibility_service_config"/>
    </service>
...
</application>

accessibility_service_config.xml:

<?xml version="1.0" encoding="utf-8"?>
<accessibility-service xmlns:android="http://schemas.android.com/apk/res/android"
    android:accessibilityEventTypes="typeAllMask"
    android:accessibilityFeedbackType="feedbackAllMask"
    android:accessibilityFlags="flagDefault"
    android:canRetrieveWindowContent="false"
    android:description="your description"
    android:notificationTimeout="100"
    android:packageNames="your app package, ex: ex: com.example.android"
    android:settingsActivity="your settings activity ex: com.example.android.MainActivity" />

for more info look at https://developer.android.com/guide/topics/ui/accessibility/service