Expand ListView item with animation

Question

I have a ListView. Initially, the ListView contains some data. When the user clicks on an item, another layout will be dynamically added to that it

Answer 1

I think I was looking for the same as was asked, I was looking for a way to animate the expanding of the listview item as some new content is shown (I was just changing the visibility on some views from GONE to VISIBLE). I had used the answer by mirroredAbstraction to help me apply a translate animation (I didn't want a rotate animation):

to each of the views. It create a nice effect, but looking closely, the listview item was actually suddenly expanding to the entire size that would be needed, then the animation dropped the views into place. But what I wanted was the effect of the listview item growing down as the views come into visibility.

I found exactly what I was looking for here: expanding-listview-items

The blogger has a link to his github sample, here: ExpandAnimationExample

If you find these sites gone, please inform me and I will make my copy available.

he put a negative margin on the content to come into visibility as well as setting visibility to GONE:

android:layout_marginBottom="-50dip"

and wrote an animation manipulating the bottom margin:

public class ExpandAnimation extends Animation {
...
    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t) {
        super.applyTransformation(interpolatedTime, t);

        if (interpolatedTime < 1.0f) {

            // Calculating the new bottom margin, and setting it
            mViewLayoutParams.bottomMargin = mMarginStart
                    + (int) ((mMarginEnd - mMarginStart) * interpolatedTime);

            // Invalidating the layout, making us seeing the changes we made
            mAnimatedView.requestLayout();
        }
        ...
    }
}

and it looks very nice. I found his answer to this SO (possible duplicate?) question:

Adding animation to a ListView in order to expand/collapse content

Also, please let me know if you know another way to do the same thing.