Sunday, 16 October 2016

View animation Expand and Collapse - Android

This Post helps to animate the android views expand and collapse like Expandable list view.

Find below the code snippet.

ViewAnimationUtils.java







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import android.view.View;
import android.view.ViewGroup;
import android.view.animation.Animation;
import android.view.animation.Transformation;

public class ViewAnimationUtils {

    int animDuration = 600;
 
    public static void expand(final View view) {
        view.measure(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        final int targtetHeight = view.getMeasuredHeight();
        view.getLayoutParams().height = 0;
        view.setVisibility(View.VISIBLE);
        Animation animation = new Animation() {
            @Override
            protected void applyTransformation(float interpolatedTime, Transformation t) {
                view.getLayoutParams().height = interpolatedTime == 1
                        ? ViewGroup.LayoutParams.WRAP_CONTENT
                        : (int) (targtetHeight * interpolatedTime);
                view.requestLayout();
            }

            @Override
            public boolean willChangeBounds() {
                return true;
            }
        };
        animation.setDuration(animDuration);
        view.startAnimation(animation);
    }

    public static void collapse(final View view) {
        final int initialHeight = view.getMeasuredHeight();
        Animation animation = new Animation() {
            @Override
            protected void applyTransformation(float interpolatedTime, Transformation t) {
                if (interpolatedTime == 1) {
                    view.setVisibility(View.GONE);
                } else {
                    view.getLayoutParams().height = initialHeight - (int) (initialHeight * interpolatedTime);
                    view.requestLayout();
                }
            }

            @Override
            public boolean willChangeBounds() {
                return true;
            }
        };
        animation.setDuration(animDuration);
        view.startAnimation(animation);
    }
}

Example
TextView description;
Button expand, collapse;
expand.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
  ViewAnimationUtils.expand(description)
 }
});

collapse.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View v) {
  ViewAnimationUtils.expand(description)
 }
});

1 comment:

Vimalan S said...

Very Informative..!