ExpandCollapseHelper.java

/*
 *
 */

package syncthing.android.ui.common;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.animation.AnimatorSet;
import android.animation.ObjectAnimator;
import android.animation.ValueAnimator;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AccelerateDecelerateInterpolator;

/**
 * Helper to animate collapse and expand animation
 */
public class ExpandCollapseHelper {
    /**
     * This method expandes the view that was clicked.
     *
     * @param expandingLayout  layout to expand
     * @param cardView         cardView
     * @param recyclerView     recyclerView
     */
    public static void animateCollapsing(final View expandingLayout, final ExpandableView cardView, final RecyclerView recyclerView, boolean wobble) {
        final int origHeight = expandingLayout.getHeight();

        ValueAnimator animator = createHeightAnimator(expandingLayout, origHeight, 0);
        animator.addListener(new AnimatorListenerAdapter() {

            @Override
            public void onAnimationEnd(final Animator animator) {
                expandingLayout.setVisibility(View.GONE);

                //reset height else recycled views never show
                ViewGroup.LayoutParams layoutParams = expandingLayout.getLayoutParams();
                layoutParams.height = origHeight;
                expandingLayout.setLayoutParams(layoutParams);

                cardView.getExpandable().setExpanded(false);

                //notifyAdapter(recyclerView, recyclerView.getLayoutManager().getPosition((View)cardView));

//                Card card = cardView.getCard();
//                if (card.getOnCollapseAnimatorEndListener()!=null)
//                    card.getOnCollapseAnimatorEndListener().onCollapseEnd(card);
            }
        });
        if (wobble) {
            AnimatorSet animatorSet = new AnimatorSet();
            animatorSet.playTogether(animator, createWobbleAnimator(cardView.getView()));
            animatorSet.start();
        } else {
            animator.start();
        }
    }

    /**
     * This method collapse the view that was clicked.
     *
     * @param expandingLayout  layout to collapse
     * @param cardView         cardView
     * @param recyclerView     recyclerView
     */
    public static void animateExpanding(final View expandingLayout, final ExpandableView cardView, final RecyclerView recyclerView, boolean wobble) {
            /* Update the layout so the extra content becomes visible.*/
        expandingLayout.setVisibility(View.VISIBLE);

        View parent = (View) expandingLayout.getParent();
        final int widthSpec = View.MeasureSpec.makeMeasureSpec(
                parent.getMeasuredWidth() - parent.getPaddingLeft() - parent.getPaddingRight(), View.MeasureSpec.AT_MOST);
        final int heightSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        expandingLayout.measure(widthSpec, heightSpec);


        ValueAnimator animator = createHeightAnimator(expandingLayout, 0, expandingLayout.getMeasuredHeight());
        if (recyclerView != null) {
            animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
                final int listViewHeight = recyclerView.getHeight();
                final int listViewBottomPadding = recyclerView.getPaddingBottom();

                final View v = findDirectChild(expandingLayout, recyclerView);

                @Override
                public void onAnimationUpdate(final ValueAnimator valueAnimator) {
                    if (recyclerView.getLayoutManager().canScrollVertically()) {
                        final int bottom = v.getBottom();
                        if (bottom > listViewHeight) {
                            final int top = v.getTop();
                            if (top > 0) {
                                //recyclerView.scrollBy(0,Math.min(bottom - listViewHeight + listViewBottomPadding, top));
                                recyclerView.smoothScrollBy(0,Math.min(bottom - listViewHeight + listViewBottomPadding + 4, top));

                            }
                        }
                    }
                }
            });
        }
        animator.addListener(new AnimatorListenerAdapter() {
            @Override
            public void onAnimationEnd(Animator animation) {
                super.onAnimationEnd(animation);
                cardView.getExpandable().setExpanded(true);

                //notifyAdapter(recyclerView,recyclerView.getLayoutManager().getPosition((View)cardView));

//                Card card = cardView.getCard();
//                if (card.getOnExpandAnimatorEndListener()!=null)
//                    card.getOnExpandAnimatorEndListener().onExpandEnd(card);

            }
        });
        if (wobble) {
            AnimatorSet animatorSet = new AnimatorSet();
            animatorSet.playTogether(animator, createWobbleAnimator((View)cardView));
            animatorSet.start();
        } else {
            animator.start();
        }
    }

    private static View findDirectChild(final View view, final RecyclerView recyclerView) {
        View result = view;
        View parent = (View) result.getParent();
        while (parent != recyclerView) {
            result = parent;
            parent = (View) result.getParent();
        }
        return result;
    }

    public static ValueAnimator createHeightAnimator(final View view, final int start, final int end) {
        ValueAnimator animator = ValueAnimator.ofInt(start, end);
        animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {

            @Override
            public void onAnimationUpdate(final ValueAnimator valueAnimator) {
                int value = (Integer) valueAnimator.getAnimatedValue();

                ViewGroup.LayoutParams layoutParams = view.getLayoutParams();
                layoutParams.height = value;
                view.setLayoutParams(layoutParams);
            }
        });

        return animator;
    }

    public static Animator createWobbleAnimator(final View view) {
        ObjectAnimator objectAnimator = ObjectAnimator.ofFloat(view, "rotationX", 0f, 30f);
        objectAnimator.setDuration(100);
        objectAnimator.setInterpolator(new AccelerateDecelerateInterpolator());
        ObjectAnimator objectAnimator2 = ObjectAnimator.ofFloat(view, "rotationX", 30f, 0f);
        objectAnimator.setDuration(100);
        objectAnimator.setInterpolator(new AccelerateDecelerateInterpolator());
        AnimatorSet set = new AnimatorSet();
        set.playSequentially(objectAnimator, objectAnimator2);
        return set;
    }

    /**
     * This method notifies the adapter after setting expand value inside cards
     *
     * @param recyclerView
     */
    public static void notifyAdapter(RecyclerView recyclerView, int position){
        if (recyclerView instanceof CardRecyclerView) {

            CardRecyclerView cardRecyclerView = (CardRecyclerView) recyclerView;
            if (cardRecyclerView.getAdapter()!=null){
                cardRecyclerView.getAdapter().notifyItemChanged(position);
            }
        }
    }
}