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):
<translate xmlns:android="http://schemas.android.com/apk/res/android"
android:interpolator="@android:anim/linear_interpolator"
android:fromYDelta="0"
android:toYDelta="-100%p"
android:duration="500"
/>
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.