So I am trying to create a "strobe" light effect in my app.
To do this I need a time delay, one of 100ms the other of 20.
Here is the code I'm using.
Thread timer = new Thread();
long longTime = 100;
long shortTime = 20;
for (int x = 0; x < 2000000; x++)
{
layout.setBackgroundColor(background);
try {
timer.sleep(longTime);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
layout.setBackgroundColor(backgroundBlack);
try {
timer.sleep(shortTime);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
The issue I have is that when I click the button to call that code, nothing happens. So I've done a bit of debugging and am pretty sure it is the timing call. I have never programmed in Java before so I am unsure how to call a Thread Sleep.
You could use a Handler as below to achieve this.
public class Strobe extends Activity {
private LinearLayout mLinearLayout;
private Handler mHander = new Handler();
private boolean mActive = false;
private boolean mSwap = true;
private final Runnable mRunnable = new Runnable() {
public void run() {
if (mActive) {
if (mSwap) {
mLinearLayout.setBackgroundColor(Color.WHITE);
mSwap = false;
mHander.postDelayed(mRunnable, 20);
} else {
mLinearLayout.setBackgroundColor(Color.BLACK);
mSwap = true;
mHander.postDelayed(mRunnable, 100);
}
}
}
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mLinearLayout = (LinearLayout) findViewById(R.id.strobe);
startStrobe();
}
private void startStrobe() {
mActive = true;
mHander.post(mRunnable);
}
}
Set a Theme to the Activity to make it full screen.
android:theme="@android:style/Theme.NoTitleBar.Fullscreen"