Android ImageView Animation


Question

I've created a layout with an image view and a web view. The web view is set to have a default visibility of gone. When the activity fires up it displays the image view first and when the web view has finished loading its url, it marks itself as visible and the imageview is marked as hidden.

When the imageview is shown, I would like it to rotate repeatedly just for a little added pizazz.

I have never done animations before in Android and all the posts I found when I asked the internet were not helpful; thus, I have returned to SO for help.

So if I start with this...

    final ImageView splash = (ImageView)findViewById(R.id.splash);

How do I create a repeated rotate animation and apply it to the ImageView?

Thanks again!

1
60
4/20/2010 2:45:42 PM

Accepted Answer

Use a RotateAnimation, setting the pivot point to the centre of your image.

RotateAnimation anim = new RotateAnimation(0f, 350f, 15f, 15f);
anim.setInterpolator(new LinearInterpolator());
anim.setRepeatCount(Animation.INFINITE);
anim.setDuration(700);

// Start animating the image
final ImageView splash = (ImageView) findViewById(R.id.splash);
splash.startAnimation(anim);

// Later.. stop the animation
splash.setAnimation(null);
102
1/9/2010 1:20:55 PM

How to rotate an image around its center:

ImageView view = ... //Initialize ImageView via FindViewById or programatically

RotateAnimation anim = new RotateAnimation(0.0f, 360.0f, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);

//Setup anim with desired properties
anim.setInterpolator(new LinearInterpolator());
anim.setRepeatCount(Animation.INFINITE); //Repeat animation indefinitely
anim.setDuration(700); //Put desired duration per anim cycle here, in milliseconds

//Start animation
view.startAnimation(anim); 
//Later on, use view.setAnimation(null) to stop it.

This will cause the image to rotate around its center (0.5 or 50% of its width/height). I am posting this for future readers who get here from Google, as I have, and who wish to rotate the image around its center without defining said center in absolute pixels.


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