Develop Reference

ChangeBounds Android Transition

I have a recyclerview in my app, and each row contains a button which shows a text in the same cell, under the button. I have used ChangeBounds transition to make the text appear with a smooth animation, increasing the row height until the text is completely shown. So when a button is clicked, I do:
TransitionManager.beginDelayedTransition(row, transition)
holder.hiddenText.setVisibility(View.VISIBLE)
It works well, but whith a problem. The hidden text appears with an animation which increases its height, as expected. But the row height is not animated, and it jumps from the original height until the final height without any animation.
Is there any way to achieve a height transition over the row, to increase at the same time as the text?

If you want animation to take effect for row also, then you need to perform beginDelayedTransition() on a one layer higher of the row, which in your case maybe is the actual RecyclerView.

Try this on your row's layout
public static void expand(final View v) {
v.measure(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
final int targetHeight = v.getMeasuredHeight();
// Older versions of android (pre API 21) cancel animations for views with a height of 0.
v.getLayoutParams().height = 1;
v.setVisibility(View.VISIBLE);
Animation a = new Animation()
{
#Override
protected void applyTransformation(float interpolatedTime, Transformation t) {
v.getLayoutParams().height = interpolatedTime == 1
? LayoutParams.WRAP_CONTENT
: (int)(targetHeight * interpolatedTime);
v.requestLayout();
}
#Override
public boolean willChangeBounds() {
return true;
}
};
// 1dp/ms
a.setDuration((int)(targetHeight / v.getContext().getResources().getDisplayMetrics().density));
v.startAnimation(a);
}
Linear or Relative layout of row's will animate and expand. Hope this solves your problem

How to smoothen Linear layout height animation, having heavy content

Animation animation = new Animation() {
#Override
protected void applyTransformation(float interpolatedTime, Transformation t) {
ViewGroup.LayoutParams params = slidingPane.getLayoutParams();
int calculatedHeight = expandedHeight - ((int) (expandedHeight * interpolatedTime));
if (calculatedHeight <= collapsedHeight) {
calculatedHeight = collapsedHeight;
}
params.height = calculatedHeight;
slidingPane.setLayoutParams(params);
slidingPane.requestLayout();
}
#Override
public boolean willChangeBounds() {
return true;
}
};
animation.setDuration(ANIMATION_DURATION);
animation.setAnimationListener(animationListener);
slidingPane.startAnimation(animation);
SlidingPane is a LinearLayout and it has a ListView as a child. ListView contains images in every row.
Now this code is working absolutely fine, but animation is not smooth. If I remove images from listview then it works fine.
I have already tried following things based on the answers on SO on similar questions -
1. Hide the content of sliding pane before animation and then again make them visible on animation end. It helps but behavior looks very odd
2. Set android:animateLayoutChanges="true" in xml, but its not animating anything
Is there anyway to solve this problem?

Instead of manually changing the height on each animation step, you should try to use the more systematic animation, like ValueAnimator, or ObjectAnimator:
slidingPane.animate().scaleY(0f).setInterpolator(new AccelerateDecelerateInterpolator()).setDuration(ANIMATION_DURATION);
You can use pivotY/pivotY on the view to control the anchor point of the scale animation.
Related docs:
https://developer.android.com/reference/android/animation/ValueAnimator.html
https://developer.android.com/reference/android/animation/ObjectAnimator.html
https://developer.android.com/guide/topics/graphics/prop-animation.html

RecyclerView scrollToPositionWithOffset with animation

Im trying to animate a card view's position and resize it to fit screen at the same time.
When the user clicks a button inside the cardview, the cardview should expand to the size of its container, and scroll up to become fully visible at the same time
in my custom animator class, im using the following function:
#Override
protected void applyTransformation(float interpolatedTimeTransformation t) {
int newHeight = (int) (startHeight + (targetHeight - startHeight) *interpolatedTime);
view.getLayoutParams().height = newHeight;
((LinearLayoutManager) MainPage.mainGroupRecycler.getLayoutManager()).scrollToPositionWithOffset(MainPage.mainGroupRecycler.getChildAdapterPosition((CardView) view.getParent()), 0);
view.requestLayout();
}
in the following case, the recyclerview instantly shows the cardview at the top of the visible area without animating the scrolling, then it animates the resize. I need it to scroll at the same time the resize is happening.
i tried calling another scroll function:
MainPage.mainGroupRecycler.scrollToPosition(MainPage.mainGroupRecycler.getChildAdapterPosition((CardView) view.getParent()));
But the problem with this is that the scrolling will only animate after the resize is complete.
I need the resizing and the scrolling to happen simultaneously.
Any help will be appreciated

For the two effects to occur in tandem, you must start the animation of the view, and call scrollToPosition at the same time.
Also, remove the call to "scrollToPosition" from within the animation's applyTransformation method. This is bad because it's telling the layout manager that it needs to scroll to a certain position on every iteration of the animation, which could occur hundreds of times. You only need to call scrollToPosition once.
Also, instead of scrollToPosition, use smoothScrollToPosition for a nice smooth scroll effect.

I figured out the solution.
In my animator class:
#Override
protected void applyTransformation(float interpolatedTime, Transformation t){
calculatedOffset = (int) (tempOffset*interpolatedTime);
tempOffset = tempOffset-calculatedOffset;
recyclerView.scrollBy(0,calculatedOffset);
int newHeight = (int) (startHeight + (targetHeight - startHeight) * interpolatedTime);
LinearLayout ll = (LinearLayout)view.findViewById(R.id.cardchild);
ll.setLayoutParams(new CardView.LayoutParams(ll.getWidth(),newHeight));
}
A note to anyone using a similar approach, make sure to set recyclerView.setItemViewCacheSize(itemList.size) if u have a large number of items because if you dont, the cached objects will be reused thus resizing multiple items and not just the item u clicked

Android fragment animation first time stuck

I am doing an animation inside a fragment.
I have 2 views on top of each other, one of them set on View.GONE.
when I press a button I want my 2nd fragment to translate animation from the bottom to top.
I am doing it fine and it's working great,
the problem is that in my first run, the xml view is gone, but he is in the same Y he is suppose to be.
so the first animation I do isn't doing anything, just switch from GONE to VISIBLE, after that, I press dismiss and the fragment goes away and comes back just like I want too.
my problem is just the first run.
how can I set my view Y to be 100% below my screen?
here's the code I use :
private void moreCustomAnimation() {
int yOffset = moreMenuFrameLayout.getMeasuredHeight();
TranslateAnimation moveAnim = new TranslateAnimation(0, 0, yOffset, 0);
moveAnim.setDuration(500);
moveAnim.setFillAfter(true);
blackView.setVisibility(View.VISIBLE);
moreMenuFrameLayout.setVisibility(View.VISIBLE);
moreMenuFrameLayout.startAnimation(moveAnim);
moveAnim.setAnimationListener(new Animation.AnimationListener() {
#Override
public void onAnimationStart(Animation animation) {
}
#Override
public void onAnimationEnd(Animation animation) {
}
#Override
public void onAnimationRepeat(Animation animation) {
}
});
}
on the way out of the screen I use the same code just switch the
yOffset to the other Y integer, and set the view to GONE at animation end.
thanks a lot in advance for any help !

You can use the onGlobalLayout event to set the position of the view.
Like this:
moreMenuFrameLayout.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
moreMenuFrameLayout.setTranslationY(moreMenuFrameLayout.getMeasuredHeight());
moreMenuFrameLayout.getViewTreeObserver().removeOnGlobalLayoutListener(this);
}
});
This event happens when your views get their actual size and position before being drawn to the screen. However, they happen every time the view is drawn so you must remember to remove the listener right after the first time.
HTH

First time you can add the 'yOffset' value to the view orginal points
moreMenuFrameLayout.setY(currentYpostition + yOffset)
and this will place the view to the bottom of the screen. You can enable the visibility when the animation starts.

expand animation issue of the last item in ListView android

I apply the expand animation in ListView using,
#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();
// Making sure we didn't run the ending before (it happens!)
} else if (!mWasEndedAlready) {
mViewLayoutParams.bottomMargin = mMarginEnd;
mAnimatedView.requestLayout();
if (mIsVisibleAfter) {
mAnimatedView.setVisibility(View.GONE);
}
mWasEndedAlready = true;
}
}
Here, when I try to click the last item of the ListView, the last item of my Listview expand downward so, I cannot see the whole contents of the last one without scrolling upward.
In other words, If I click the last one, I want my focus on the bottom side of the last item (automatically scrolling) so I can see the full contents of the last one immediately.
Is there any way to solve it?

Maybe this will help:(First check if the user has clicked the last item)
listView.setSelection(ListAdapter.getCount() - 1);
Or sometimes you have to do something like this:
listView.post(new Runnable()
{
#Override
public void run()
{
listView.setSelection(ListAdapter.getCount() - 1);
}
});