com.architjn.acjmusicplayer.elements.ScrollAwareFABBehavior.java Source code

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Here is the source code for com.architjn.acjmusicplayer.elements.ScrollAwareFABBehavior.java

Source

package com.architjn.acjmusicplayer.elements;

import android.content.Context;
import android.support.design.widget.CoordinatorLayout;
import android.support.design.widget.FloatingActionButton;
import android.support.v4.view.ViewCompat;
import android.support.v4.view.animation.FastOutSlowInInterpolator;
import android.util.AttributeSet;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.view.animation.Interpolator;

import com.architjn.acjmusicplayer.R;

/*
 * Copyright 2015 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

public class ScrollAwareFABBehavior extends FloatingActionButton.Behavior {
    private static final Interpolator INTERPOLATOR = new FastOutSlowInInterpolator();
    private boolean mIsAnimatingOut = false;

    public ScrollAwareFABBehavior(Context context, AttributeSet attrs) {
        super();
    }

    @Override
    public boolean onStartNestedScroll(final CoordinatorLayout coordinatorLayout, final FloatingActionButton child,
            final View directTargetChild, final View target, final int nestedScrollAxes) {
        // Ensure we react to vertical scrolling
        return nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL
                || super.onStartNestedScroll(coordinatorLayout, child, directTargetChild, target, nestedScrollAxes);
    }

    @Override
    public void onNestedScroll(final CoordinatorLayout coordinatorLayout, final FloatingActionButton child,
            final View target, final int dxConsumed, final int dyConsumed, final int dxUnconsumed,
            final int dyUnconsumed) {
        super.onNestedScroll(coordinatorLayout, child, target, dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed);
        if (dyConsumed > 0 && !this.mIsAnimatingOut && child.getVisibility() == View.VISIBLE) {
            // User scrolled down and the FAB is currently visible -> hide the FAB
            animateOut(child);
        } else if (dyConsumed < 0 && child.getVisibility() != View.VISIBLE) {
            // User scrolled up and the FAB is currently not visible -> show the FAB
            animateIn(child);
        }
    }

    // Same animation that FloatingActionButton.Behavior uses to hide the FAB when the AppBarLayout exits
    private void animateOut(final FloatingActionButton button) {
        Animation anim = AnimationUtils.loadAnimation(button.getContext(), R.anim.abc_slide_out_bottom);
        anim.setInterpolator(INTERPOLATOR);
        anim.setDuration(600L);
        anim.setAnimationListener(new Animation.AnimationListener() {
            public void onAnimationStart(Animation animation) {
                ScrollAwareFABBehavior.this.mIsAnimatingOut = true;
            }

            public void onAnimationEnd(Animation animation) {
                ScrollAwareFABBehavior.this.mIsAnimatingOut = false;
                button.setVisibility(View.GONE);
            }

            @Override
            public void onAnimationRepeat(final Animation animation) {
            }
        });
        button.startAnimation(anim);
    }

    // Same animation that FloatingActionButton.Behavior uses to show the FAB when the AppBarLayout enters
    private void animateIn(FloatingActionButton button) {
        button.setVisibility(View.VISIBLE);
        Animation anim = AnimationUtils.loadAnimation(button.getContext(), R.anim.abc_slide_in_bottom);
        anim.setDuration(600L);
        anim.setInterpolator(INTERPOLATOR);
        button.startAnimation(anim);
    }
}