Android How To Keep Screen On While Using webView

android, java

Solution

There are 3 possible ways of doing this, two are preferable and similar in function it’s just personal preference which you use. The other is a bit more aggressive and can be used in other scenarios where you want other parts of the system to stay awake as well (like the processor).

Here’s the ways:

Inform the `window manager` in `onCreate` you want the screen to stay on

This Activity below keeps the screen on using the window manager, you don’t have to worry about managing this it will be kept on for the duration of the Activity lifecycle. The screen may dim but it won’t turn off. No permissions are needed in your manifest.

package com.mysite;
import com.mysite.R;
import android.app.Activity;
import android.os.Bundle;
import android.view.WindowManager;
import android.webkit.WebView;

public class MainActivity extends Activity {
    public WebView myWebView = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.activity_flag);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
        myWebView = new WebView(this);      
        myWebView.loadUrl("http://www.mysite.com");

    }
}

`WakeLock` – used for critical downloads or things that you definitely don’t want the Android system shutting down for

This Activity aquires a wakelock to keep the screen on whilst in this activity. This requires a permission in your manifest. It is important to manage your wakelocks and always release them when finished (in onPause).

public class MainActivity extends Activity {
    private static final String TAG = "com.mysite.ScreenOnWakeLockActivity.WAKE_LOCK_TAG";
    private WakeLock wakeLock;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_flag);

        PowerManager powerManager = (PowerManager) getSystemService(POWER_SERVICE);
        wakeLock = powerManager.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK, TAG);

        myWebView = new WebView(this);      
        myWebView.loadUrl("http://www.mysite.com");
    }

    @Override
    protected void onResume() {
        super.onResume();
        wakeLock.acquire();
    }

    @Override
    protected void onPause() {
        super.onPause();
        wakeLock.release();
    }
}

Declare the screen stays on in your `XML layout`

This activity keeps the screen on using a flag in the XML layout file we are using `android:keepScreenOn=”true”` no manifest permissions are needed.

/**
 * This activity keeps the screen on using a flag in the XML layout file we are using 'android:keepScreenOn="true"'
 * We don't use a wakelock so no manifest permissions are needed
 *
 * @author chirag.saga
 *
 */
public class MainActivity extends Activity {
    public WebView myWebView = null;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.activity_flag);

        myWebView = new WebView(this);      
        myWebView.loadUrl("http://www.mysite.com");
    }
}

Problem

Original source