How to get event when power button android is pressed-CodePudding

Need help, I'm making a screen locker app using React Native, and want to get an event when the android power button is pressed...

Thanks in advance..

CodePudding user response：

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.KeyEvent
import android.widget.TextView
import android.widget.Toast

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

    }

    // 1. onKeyDown is a boolean function, which returns the state of 
    //the KeyEvent.
    // 2. This function is an internal function, that functions outside 
    //the actual application.
    // 3. When any Key is pressed, a Toast appears with the following 
    //message.
    // 4. This code can check if the device responds to any Key.
    //override fun onKeyDown(keyCode: Int, event: KeyEvent?): Boolean {

        when (keyCode) {
            KeyEvent.KEYCODE_VOLUME_DOWN -> 
Toast.makeText(applicationContext, "Volume Down Key Pressed", 
Toast.LENGTH_SHORT).show()
            KeyEvent.KEYCODE_VOLUME_UP -> 
Toast.makeText(applicationContext, 
"Volume Up Key Pressed", Toast.LENGTH_SHORT).show()
            KeyEvent.KEYCODE_POWER -> Toast.makeText(applicationContext, 
"Power Key Pressed", Toast.LENGTH_SHORT).show()
        }
        return true
    }
}

CodePudding user response：

*You cannot override the power button press from your application. But when you press power button the screen turns on/off. So you can detect this using a broadcast receiver.

<receiver android:name=".MyBroadCastReciever">
<intent-filter>
    <action android:name="android.intent.action.SCREEN_OFF"/>
    <action android:name="android.intent.action.SCREEN_ON"/>
</intent-filter>
</receiver>

MyBroadCastReciever.java

public class MyBroadCastReciever extends BroadcastReceiver {

@Override
public void onReceive(Context context, Intent intent) {
    if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
        //Take count of the screen off position
    } else if (intent.getAction().equals(Intent.ACTION_SCREEN_ON)) {
        //Take count of the screen on position
    }
}
}
Hope this is helpful for you.

Note:-For to keep my broadcast receiver always running in Background.I am written one Background Service which continuously start in background and give boost to my broadcast receiver.*

CodePudding user response：

You can use the react-native-keyevent package for react native.

componentDidMount() {
KeyEvent.onKeyDownListener((keyEvent) => {
    if (keyEvent.keyCode === 'Keycode of the power button'){
        this.timeout = setTimeout(() => {
            //Your SOS Function here
        }, 1000)
    }
});

KeyEvent.onKeyUpListener((keyEvent) => {
    if (keyEvent.keyCode === 'Keycode of the power button'){
        clearTimeout(this.timeout)
    }
    })
}

componentWillUnmount() {
  KeyEvent.removeKeyDownListener();
  KeyEvent.removeKeyUpListener();
}