Android - Blinking image using the Alpha fade animation
I've been struggling for a few days on this, finally just decided to ask. It's so simple I've got to be missing something very basic.
I have an XML layout page with an image defined. I have two anim XML pages, one to change alpha from 0 to 1, and the other from 1 to 0 in order to create a "blinking" effect. So the alphaAnimation is defined in XML, I just need to call it.
The image pops up, but there's no looping blinking effect.
public class blinker extends Activity {
//create name of animation
Animation myFadeInAnimation;
Animation myFadeOutAnimation;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.scanning_view);
//grab the imageview and load the animations
ImageView myImageView = (ImageView) findViewById(R.id.blinkingView01);
Animation myFadeInAnimation = AnimationUtils.loadAnimation(null, R.anim.fade_in);
Animation myFadeOutAnimation = AnimationUtils.loadAnimation(null, R.anim.fade_out);
//fade it in, and fade it out.
myImageView.startAnimation(myFadeInAnimation);
myImageView.startAnimation(myFadeOutAnimation);
}
}
Two XML Animation layouts in Anim resource:
<?xml version="1.0" encoding="UTF-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<alpha android:fromAlpha="0.0"
android:toAlpha="1.0"
android:interpolator="@android:anim/accelerate_interpolator"
android:duration="50" android:repeatCount="infinite"/>
</set>
And the other:
<?xml version="1.0" encoding="UTF-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<alpha android:fromAlpha="1.0" android:toAlpha="0.0"
android:interpolator="@android:anim/accelerate_interpolator"
android:duration="1000" android:repeatCount="infinite"/>
</set>
The best way to tween fade :
ImageView myImageView = (ImageView) findViewById(R.id.imageView2);
Animation myFadeInAnimation = AnimationUtils.loadAnimation(Splash.this, R.anim.tween);
myImageView.startAnimation(myFadeInAnimation);
in your res/anim/ create tween.xml tween 1s start opacity 0 to 1 and reverse infinit...
<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<alpha
android:fromAlpha="0.0"
android:toAlpha="1.0"
android:duration="1000"
android:repeatMode="reverse"
android:repeatCount="infinite" />
</set>
Why not use android:repeatMode="reverse"
You can use the below alpha animation to set the blinking effects to the views in android.
blinkanimation= new AlphaAnimation(1, 0); // Change alpha from fully visible to invisible
blinkanimation.setDuration(300); // duration
blinkanimation.setInterpolator(new LinearInterpolator()); // do not alter animation rate
blinkanimation.setRepeatCount(3); // Repeat animation infinitely
blinkanimation.setRepeatMode(Animation.REVERSE);
After this add the animation to your view like,
view.setAnimation(blinkanimation);
or
view.startAnimation(blinkanimation);
If someone will decide to use programmatic version:
val anim = AlphaAnimation(1.0f, 0.0f)
anim.duration = 750
anim.fillAfter = true
// here is repeat settings
anim.repeatMode = AlphaAnimation.REVERSE // ping pong mode
anim.repeatCount = 1 // count of repeats
yourView.startAnimation(anim)