package com.ble.gsense.rbq.view;/** * Created by rbq on 2016/12/8. */import java.util.Random;import java.util.concurrent.atomic.AtomicBoolean;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.Rect;import android.os.Handler;import android.os.Message;import android.util.AttributeSet;import android.view.View;import com.ble.gsense.rbq.R;public class MusicPlayBarView extends View {    private byte[] mBytes;    private Rect mRect = new Rect();    private Paint mForePaint = new Paint();    //添加这个标志的原因是用于判断当前是否进入循环了。如果没有则在onDraw()方法的时候进入。为什么需要这样呢。原因是RecyclerView的一个资源节约的机制来的，在item不在页面显示中的时候就会销毁掉这个View,导致无法在重新进入的时候跳动。然后就是有的时候他不会销毁，但是会暂停住整个状态，就是这个item处于第一个超出界面的item时不会销毁（个人猜测没看源码）。所以导致了滑动RecyclerView回来之后不会跳动的问题。所以添加这个用于解决此问题。    private AtomicBoolean mInHandlerFlag=new AtomicBoolean(false);    public MusicPlayBarView (Context context) {        super(context);        init();    }    public MusicPlayBarView (Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);        init();    }    public MusicPlayBarView (Context context, AttributeSet attrs) {        super(context, attrs);        init();    }    public boolean isShow() {        return super.isShown();    }    @Override    protected void onAttachedToWindow() {        super.onAttachedToWindow();        mInHandlerFlag.set(false);    }    private Handler mHandler = new Handler() {        @Override        public void handleMessage(Message msg) {            if (!MusicPlayBarView .this.isShown())                return;            mHandler.removeMessages(0);            mInHandlerFlag.set(true);            Random random = new Random();            byte[] bytes = getBytes(987);            bytes = getBytes(random.nextInt());            if (isShow.get()) {                mHandler.sendEmptyMessageDelayed(0, 100);            }            updateVisualizer(bytes);        }    };    public void show() {        if (!isShow.get()) {            isShow.set(true);            mHandler.sendEmptyMessage(0);        }    }    public void hide() {        isShow.set(false);        mHandler.sendEmptyMessage(0);    }    private AtomicBoolean isShow = new AtomicBoolean(false);    private byte[] getBytes(int data) {        byte[] bytes = new byte[4];        bytes[0] = (byte) (data & 0xff);        bytes[1] = (byte) ((data & 0xff00) >> 8);        bytes[2] = (byte) ((data & 0xff0000) >> 16);        bytes[3] = (byte) ((data & 0xff000000) >> 24);        return bytes;    }    public static byte[] getBytes(long data) {        byte[] bytes = new byte[8];        bytes[0] = (byte) (data & 0xff);        bytes[1] = (byte) ((data >> 8) & 0xff);        bytes[2] = (byte) ((data >> 16) & 0xff);        bytes[3] = (byte) ((data >> 24) & 0xff);        bytes[4] = (byte) ((data >> 32) & 0xff);        bytes[5] = (byte) ((data >> 40) & 0xff);        bytes[6] = (byte) ((data >> 48) & 0xff);        bytes[7] = (byte) ((data >> 56) & 0xff);        return bytes;    }    public byte[] getBytes(float data) {        int intBits = Float.floatToIntBits(data);        return getBytes(intBits);    }    public byte[] getBytes(double data) {        long intBits = Double.doubleToLongBits(data);        return getBytes(intBits);    }    private void init() {        mBytes = null;        mForePaint.setStrokeWidth(1f);        mForePaint.setAntiAlias(true);        mForePaint.setColor(Color.rgb(0, 143, 229));    }    public void updateVisualizer(byte[] bytes) {        byte[] model = new byte[bytes.length];        for (int i = 0; i < bytes.length - 1; i++) {            model[i] = bytes[i];        }        mBytes = bytes;        invalidate();    }    private void drawRect(float left, float width, float top, Canvas canvas) {        final float right = left + width;        final float bottom = getHeight();        final float thickness = 3.0f;        float currenttop = bottom;        while (true) {            canvas.drawRect(left, currenttop - thickness, right, currenttop,                    mForePaint);            currenttop -= thickness;            if (currenttop <= top)                break;        }    }    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        if(isShow.get()&&!mInHandlerFlag.get()){            mHandler.sendEmptyMessage(0);            return;        }        if (mBytes == null) {            return;        }        int sum = 0;        for (int i = 0; i < mBytes.length; i++)            sum += mBytes[i];        if (sum == 0)            return;        mRect.set(0, 0, getWidth(), getHeight());        int length = mBytes.length;        final float width = getResources().getDimensionPixelSize(                R.dimen.music_play_animation_width);// play bar width        final float blankWidth = getResources().getDimensionPixelSize(                R.dimen.music_play_animation_blank_area_width);// blank area width        final float lastOffSet = width + blankWidth;        float left, top;        for (int i = 0; i < length; i++) {            left = lastOffSet * i;// every play bar start x position.            top = mRect.height() / 2 + ((byte) mBytes[i])                    * (mRect.height() / 2) / 128;            drawRect(left, width, top, canvas);        }    }}