How do I make a strobe light effect on Android?

Question

For my app, I want a strobe light with multi colors to play, how do I do this?

Answer 1

If you want different colors and such, then you can just create a View in your XML to take up the whole screen width. Then based on an AlarmManager you can use setBackground() to make it a color of your choice.

It might be more beneficial to use a Handler instead of AlarmManager, but you can look at both to see what suits your needs.

Answer 2

If you want your screen to flash with different colors, that is just a matter of making a timer and having the main view change background colors every so often.

javax.swing.Timer can be used to change the screen every so often:

Timer colorChanger = new Timer(500 /*milis between each color change*/, new TimeListener(this) );
colorChanger.start();

Where TimeListener will be an ActionListener that changes the background color of a specified activity. TimerListener could look like this:

public class TimerListener implements ActionListener {
    public TimerListener(Activity activity) {
        this.backgroundToChange = activity;
    }
    private Activity backgroundToChange = null; // the activity who's background we will change
    private int numFrames = 0; //the number of frames that have passed
    public void actionPerformed(ActionEvent evt) { //happens when the timer will go off
        numFrames++;
        switch ( numFrames % 2 ) { // every other time it will make the background red or green
            case 0: backgroundToChange.getContentView().setBackgroundColor(Color.RED);
            case 1: backgroundToChange.getContentView().setBackgroundColor(Color.GREEN);
        }
    }
}

You're gonna need to import javax.swing.Timer and ActionListener and ActionEvent are in java.awt.event.

If you're using android however, you might want to consider using another class that is designed for android other than Timer. Timer is designed for swing and might not work well if you are using it on android. Any other timer like class will work similar to Timer though.