android view animate and without animation acts differently

Question

when I use case 1 it works as expected , but use animate (case2) the view never becomes visible!

case 1>

viewstub.setVisibility(View.GONE);
mContentLoaded = false;
showContentOrLoadingIndicator(mContentLoaded);

in this View will become invisible and visible again!

case 2>

viewstub.setVisibility(View.GONE); 

viewstub.animate().alpha(0f).setDuration(mShortAnimationDuration)
            .setListener(new AnimatorListenerAdapter() {
                @Override
                public void onAnimationEnd(Animator animation) {
                    viewstub.setVisibility(View.GONE);
                }
            });

in this View will become invisible and never becomes visible again! any solutions or reason ?

private void showContentOrLoadingIndicator(boolean contentLoaded) {
        // Decide which view to hide and which to show.
        final View showView = contentLoaded ? listView : mLoadingView;
        final View hideView = contentLoaded ? mLoadingView : listView;

        // Set the "show" view to 0% opacity but visible, so that it is visible
        // (but fully transparent) during the animation.
        showView.setAlpha(0f);
        showView.setVisibility(View.VISIBLE);

        // Animate the "show" view to 100% opacity, and clear any animation
        // listener set on
        // the view. Remember that listeners are not limited to the specific
        // animation
        // describes in the chained method calls. Listeners are set on the
        // ViewPropertyAnimator object for the view, which persists across
        // several
        // animations.
        showView.animate().alpha(1f).setDuration(mShortAnimationDuration)
                .setListener(null);

        // Animate the "hide" view to 0% opacity. After the animation ends, set
        // its visibility
        // to GONE as an optimization step (it won't participate in layout
        // passes, etc.)
        hideView.animate().alpha(0f).setDuration(mShortAnimationDuration)
                .setListener(new AnimatorListenerAdapter() {
                    @Override
                    public void onAnimationEnd(Animator animation) {
                        hideView.setVisibility(View.GONE);
                    }
                });
    }

Dude · Accepted Answer

I don't fully understand the exact reason and haven't really delved deep into the docs, but I think I can point you in the right direction.

It seems that the issue comes from this part of the code:

showView.animate().alpha(1f).setDuration(mShortAnimationDuration)
            .setListener(null);

It's as if the animation may run and finish and only then set the listener to null(which contradicts the auto-start property. So if your list has an AnimatorListenerAdapterset to it, when calling showContentOrLoadingIndicator(true); then the

@Override
public void onAnimationEnd(Animator animation) {
    hideView.setVisibility(View.GONE);
}

method will hide your list before the listener is set to null. I found this by logging the view that gets set to GONE in onAnimationEnd

So the solution would be to set the listener to null earlier in the method chain:

showView.animate()
    .setListener(null)
    .alpha(1f)
    .setDuration(mShortAnimationDuration)

If someone can offer detailed explanations about how this can happen, I'd be interested to get further educated.

Hope this helps

android view animate and without animation acts differently

Answers (2)

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