animation for zoom in and zoom out in android for imageview

Question

How do i set zoom in and zoom out when click on imageview?I want my program to react when user click on imageview must get large to some extent and can move imageview on that screen and sometime it reduce the size along when it move on touch anywhere on the screen .when click again is go resume original size what do i do?

Answer 1

As far as I know there are two ways.

The first way:

Make a new folder in res called 'anim'. Than make a xml file inside, for example zoomin.xml. Afterwards put the following code inside.

<scale  xmlns:android="http://schemas.android.com/apk/res/android"
  android:fromXScale="1" 
  android:toXScale="5" 
  android:fromYScale="1" 
  android:toYScale="5" 
  android:pivotX="50%" 
  android:pivotY="50%" 
  android:duration="1000" 
  android:fillAfter="true">
</scale>

Make another one for zoom out, but with reversed values.

<scale  xmlns:android="http://schemas.android.com/apk/res/android"
  android:fromXScale="5" 
  android:toXScale="1" 
  android:fromYScale="5" 
  android:toYScale="1" 
  android:pivotX="50%" 
  android:pivotY="50%" 
  android:duration="1000" 
  android:fillAfter="true">
</scale>

You can change the values according to your needs. I think that they are self-explanatory.

And now in your java code.

ImageView imageView = (imageView)findViewById(R.id.yourImageViewId);

Animation zoomin = AnimationUtils.loadAnimation(this, R.anim.zoomin);
Animation zoomout = AnimationUtils.loadAnimation(this, R.anim.zoomout);
imageView.setAnimation(zoomin);
imageView.setAnimation(zoomout);

Now you only need to keep track which is the current state. And for each state execute this lines of codes:

imageView.startAnimation(zoomin);

and

imageView.startAnimation(zoomout);

For example:

imageView.setOnClickListener(new OnClickListener(){
            public void onClick(View v) {
                if(!pressed) {
                    v.startAnimation(zoomin);
                    pressed = !pressed;
                } else {
                    v.startAnimation(zoomout);
                    pressed = !pressed;
                }
            }
        });

The other way is described here : http://developer.android.com/training/animation/zoom.html.