Android Activity Not Showing When Screen is Woken Up and Lock Screen Not Disabling

Here is the base implementation I used to achieve this. It's working for my users from 2.3-4.3. You can build on it from here I'm sure. I created this very short-lived Activity, just to handle this event - You can use it as a helper Class if needs be:

import android.app.Activity;
import android.os.Bundle;
import android.view.WindowManager;

public class BlankActivity extends Activity {

    @Override
    public void onCreate(final Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        getWindow().setFlags(
                WindowManager.LayoutParams.FLAG_FULLSCREEN | WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD
                        | WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED | WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON,
                WindowManager.LayoutParams.FLAG_FULLSCREEN | WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD
                        | WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED | WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);


        // Your code here - Or if it doesn't trigger, see below
    }

    @Override
    public void onAttachedToWindow() {

        // You may need to execute your code here

    }

    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);

        if (newConfig.orientation == Configuration.ORIENTATION_LANDSCAPE) {

        } else if (newConfig.orientation == Configuration.ORIENTATION_PORTRAIT) {

        }
    }

    @Override
    public void onPause() {
        super.onPause();

        finish();
    }
}

And in the Manifest:

    <activity
        android:name="com.your.package.BlankActivity"
        android:clearTaskOnLaunch="true"
        android:configChanges="keyboardHidden|orientation|screenSize"
        android:excludeFromRecents="true"
        android:launchMode="singleInstance"
        android:noHistory="true"
        android:theme="@android:style/Theme.Translucent.NoTitleBar.Fullscreen" >
    </activity>

Contrary to other related posts, the Translucent theme did not cause an issue, neither was there a need for a layout to be added to the Activity.

Hope it works for you too.