ScaleDownShowBehavior.java

/*
 * Copyright 2017 GcsSloop
 *
 * 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 2017-03-31 03:42:32
 *
 * GitHub:  https://github.com/GcsSloop
 * Website: http://www.gcssloop.com
 * Weibo:   http://weibo.com/GcsSloop
 */

package com.gcssloop.diycode.widget.behavior;

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.ViewPropertyAnimatorListener;
import android.util.AttributeSet;
import android.view.View;

// FAB 行为控制器
public class ScaleDownShowBehavior extends FloatingActionButton.Behavior {
    public ScaleDownShowBehavior(Context context, AttributeSet attrs) {
        super();
    }

    @Override
    public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout,
                                       FloatingActionButton child, View directTargetChild,
                                       View target, int nestedScrollAxes) {
        if (nestedScrollAxes == ViewCompat.SCROLL_AXIS_VERTICAL){
            return true;
        }
        return super.onStartNestedScroll(coordinatorLayout, child, directTargetChild,
                target, nestedScrollAxes);
    }

    private boolean isAnimateIng = false;   // 是否正在动画
    private boolean isShow = true;  // 是否已经显示

    public void onNestedScroll(CoordinatorLayout coordinatorLayout, FloatingActionButton child,
                               View target, int dxConsumed, int dyConsumed,
                               int dxUnconsumed, int dyUnconsumed) {
        if ((dyConsumed > 0 || dyUnconsumed > 0) && !isAnimateIng && isShow) {// 手指上滑，隐藏FAB
            AnimatorUtil.translateHide(child, new StateListener() {
                @Override
                public void onAnimationStart(View view) {
                    super.onAnimationStart(view);
                    isShow = false;
                }
            });
        } else if ((dyConsumed < 0 || dyUnconsumed < 0 && !isAnimateIng && !isShow)) {
            AnimatorUtil.translateShow(child, new StateListener() {
                @Override
                public void onAnimationStart(View view) {
                    super.onAnimationStart(view);
                    isShow = true;
                }
            });// 手指下滑，显示FAB
        }
    }

    class StateListener implements ViewPropertyAnimatorListener {
        @Override
        public void onAnimationStart(View view) {
            isAnimateIng = true;
        }

        @Override
        public void onAnimationEnd(View view) {
            isAnimateIng = false;
        }

        @Override
        public void onAnimationCancel(View view) {
            isAnimateIng = false;
        }
    }
}