com.guodong.sun.guodong.behavior.MyFabBehavior.java Source code

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Here is the source code for com.guodong.sun.guodong.behavior.MyFabBehavior.java

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/*
 * Copyright (C) 2017 guodongAndroid
 *
 * 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.
 *
 * Last modified 2017-05-04 15:03:21
 *
 * GitHub:   https://github.com/guodongAndroid
 * Website:  http://www.sunxiaoduo.com
 * Email:    sun33919135@gmail.com
 * QQ:       33919135
 */

package com.guodong.sun.guodong.behavior;

import android.animation.Animator;
import android.content.Context;
import android.support.design.widget.CoordinatorLayout;
import android.support.v4.view.ViewCompat;
import android.support.v4.view.animation.FastOutSlowInInterpolator;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewPropertyAnimator;
import android.view.animation.Interpolator;

public class MyFabBehavior extends CoordinatorLayout.Behavior<View> {

    private static final Interpolator INTERPOLATOR = new FastOutSlowInInterpolator();

    private float viewY;//?coordinatorLayout?
    private boolean isAnimate;//?

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

    //?
    @Override
    public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout, View child, View directTargetChild,
            View target, int nestedScrollAxes) {

        if (child.getVisibility() == View.VISIBLE && viewY == 0) {
            //??coordinatorLayout?
            viewY = coordinatorLayout.getHeight() - child.getY();
        }

        return (nestedScrollAxes & ViewCompat.SCROLL_AXIS_VERTICAL) != 0;//?
    }

    //??
    @Override
    public void onNestedPreScroll(CoordinatorLayout coordinatorLayout, View child, View target, int dx, int dy,
            int[] consumed) {
        //dy0? ?0?

        if (dy >= 0 && !isAnimate && child.getVisibility() == View.VISIBLE) {
            hide(child);
        } else if (dy < 0 && !isAnimate && child.getVisibility() == View.GONE) {
            show(child);
        }
    }

    //??
    private void hide(final View view) {
        ViewPropertyAnimator animator = view.animate().translationY(viewY).setInterpolator(INTERPOLATOR)
                .setDuration(200);

        animator.setListener(new Animator.AnimatorListener() {
            @Override
            public void onAnimationStart(Animator animator) {
                isAnimate = true;
            }

            @Override
            public void onAnimationEnd(Animator animator) {
                view.setVisibility(View.GONE);
                isAnimate = false;
            }

            @Override
            public void onAnimationCancel(Animator animator) {
                show(view);
            }

            @Override
            public void onAnimationRepeat(Animator animator) {
            }
        });
        animator.start();
    }

    //
    private void show(final View view) {
        ViewPropertyAnimator animator = view.animate().translationY(0).setInterpolator(INTERPOLATOR)
                .setDuration(200);
        animator.setListener(new Animator.AnimatorListener() {
            @Override
            public void onAnimationStart(Animator animator) {
                view.setVisibility(View.VISIBLE);
                isAnimate = true;
            }

            @Override
            public void onAnimationEnd(Animator animator) {
                isAnimate = false;
            }

            @Override
            public void onAnimationCancel(Animator animator) {
                hide(view);
            }

            @Override
            public void onAnimationRepeat(Animator animator) {
            }
        });
        animator.start();
    }
}