LyricShowView.java

package com.atguigu.mobileplayer1020.view;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.widget.TextView;

import com.atguigu.mobileplayer1020.bean.LyricBean;
import com.atguigu.mobileplayer1020.utils.DensityUtil;

import java.util.ArrayList;

/**
 * 作者：尚硅谷-杨光福 on 2017/1/13 14:20
 * 微信：yangguangfu520
 * QQ号：541433511
 * 作用：自定义显示歌词的控件
 */
public class LyricShowView extends TextView {
    private final Context mContext;
    private int width;
    private int height;
    private ArrayList<LyricBean> lyricBeen;
    private Paint paint;
    private Paint nopaint;
    /**
     * 歌词的索引
     */
    private int index = 0;
    private float textHeight;
    /**
     * 歌曲当前播放的进程
     */
    private int currentPosition;
    private float sleepTime;
    private float timePoint;

    public LyricShowView(Context context, AttributeSet attrs) {
        super(context, attrs);
        this.mContext = context;
        textHeight = DensityUtil.dip2px(mContext,20);
        initView();


    }

    private void initView() {
        //创建画笔
        paint = new Paint();
        paint.setTextSize(DensityUtil.dip2px(mContext,16));
        paint.setColor(Color.GREEN);
        paint.setTextAlign(Paint.Align.CENTER);
        paint.setAntiAlias(true);

        nopaint = new Paint();
        nopaint.setTextSize(DensityUtil.dip2px(mContext,16));
        nopaint.setColor(Color.WHITE);
        nopaint.setTextAlign(Paint.Align.CENTER);
        nopaint.setAntiAlias(true);


//        lyricBeen = new ArrayList<>();
//        //添加歌词列表
//        LyricBean lyricBean = new LyricBean();
//        for (int i = 0; i < 1000; i++) {
//            //歌词内容
//            lyricBean.setContent("aaaaaaaaaaa" + i);
//            //休眠时间
//            lyricBean.setSleepTime(i + 1000);
//            //时间戳
//            lyricBean.setTimePoint(i * 1000);
//            //添加到集合中
//            lyricBeen.add(lyricBean);
//            //重新创建
//            lyricBean = new LyricBean();
//
//        }
    }



    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        width = w;
        height = h;
    }


    /**
     * 绘制歌词
     */

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        if (lyricBeen != null && lyricBeen.size() > 0) {




            if(index != lyricBeen.size()-1){
                float plush = 0;

                if(sleepTime==0){
                    plush = 0;
                }else{
                    // 这一句花的时间： 这一句休眠时间  =  这一句要移动的距离：总距离(行高)
                    //这一句要移动的距离 = （这一句花的时间/这一句休眠时间） * 总距离(行高)
                    plush = ((currentPosition-timePoint)/sleepTime)*textHeight;
                }


                canvas.translate(0,-plush);

            }

            //绘制歌词
            //当前句-绿色
            String content = lyricBeen.get(index).getContent();
            canvas.drawText(content, width / 2, height / 2, paint);
            //绘制前面部分

            float tempY = height / 2;
            for (int i = index - 1; i >= 0; i--) {

                tempY = tempY - textHeight;
                if (tempY < 0) {
                    break;
                }

                String preContent = lyricBeen.get(i).getContent();
                canvas.drawText(preContent, width / 2, tempY, nopaint);
            }


            //绘制后面部分

            tempY = height / 2;
            for (int i = index + 1; i < lyricBeen.size(); i++) {
                tempY = tempY + textHeight;
                if (tempY > height) {
                    break;
                }
                String nextContent = lyricBeen.get(i).getContent();
                canvas.drawText(nextContent, width / 2, tempY, nopaint);
            }

        } else {


            //没有歌词
            canvas.drawText("没有找到歌词...", width / 2, height / 2, paint);
        }


    }

    /**
     * 根据当前播放的位置，计算高亮哪句，并且与歌曲播放同步
     *
     * @param currentPosition
     */
    public void setNextShowLyric(int currentPosition) {
        this.currentPosition = currentPosition;
        if(lyricBeen ==null || lyricBeen.size()==0)
            return;

        for (int i=1;i<lyricBeen.size();i++){

            if(currentPosition <lyricBeen.get(i).getTimePoint()){

                int indexTemp = i - 1;

                if(currentPosition >= lyricBeen.get(indexTemp).getTimePoint()){
                    //就我们要找的高亮的哪句
                    index = indexTemp;//某一句歌词的索引
                    sleepTime = lyricBeen.get(indexTemp).getSleepTime();
                    timePoint = lyricBeen.get(indexTemp).getTimePoint();

                }

            }else{
                index = i;
            }
        }

        invalidate();//强制绘制
    }

    /**
     * 设置歌词列表
     * @param lyricBeens
     */
    public void setLyrics(ArrayList<LyricBean> lyricBeens) {
        this.lyricBeen = lyricBeens;
    }
}