Android从右向左滑的折线图

最近项目中有个仿安居客折线图的功能（不包含缩放），网上找了一大堆，没找到合适的，就找了一个从左到右的demo改成了反向的，先上效果图：

    1：可滑动，默认从右向左滑动，X轴文字跟随滑动

    2：可绘制多条折线

    3：X,Y轴线条以及折线颜色直接在XML设置

    4：可点击X轴文本，以及折点，折点数显示（因为我的需求里没有，没在效果里显示，有需要将代码里注释部分关闭即可）

                                                

Demo请戳这里

使用方式：

1:使用ChartView

import android.animation.Animator;
import android.animation.ValueAnimator;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.util.Log;
import android.util.TypedValue;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.animation.DecelerateInterpolator;
import android.widget.HorizontalScrollView;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * 自定义折线图
 * Created by xiaoyunfei on 16/11/29.
 */
public class ChartView extends HorizontalScrollView {
    //xy坐标轴颜色
    private int xylinecolor = 0xffe2e2e2;
    //xy坐标轴宽度
    private int xylinewidth = dpToPx(1);
    //xy坐标轴文字颜色
    private int xytextcolor = 0xff7e7e7e;
    //xy坐标轴文字大小
    private int xytextsize = spToPx(12);
    //折线图中折线的颜色
    private int linecolor = 0xff02bbb7;
    private int linecolor1 = 0xff02bbb7;
    //x轴各个坐标点水平间距
    private int interval = dpToPx(50);
    //背景颜色
    private int bgcolor = 0x00000000;
    //是否在ACTION_UP时，根据速度进行自滑动，没有要求，建议关闭，过于占用GPU
    private boolean isScroll = false;
    //绘制XY轴坐标对应的画笔
    private Paint xyPaint;
    //绘制XY轴的文本对应的画笔
    private Paint xyTextPaint;
    //画折线对应的画笔
    private Paint linePaint;
    private Paint linePaint2;
    private int width;
    private int height;
    //x轴的原点坐标
    private int xOri;
    //y轴的原点坐标
    private int yOri;
    //第一个点X的坐标
    private float xInit;
    //第一个点对应的最大Y坐标
    private float maxXInit;
    //第一个点对应的最小X坐标
    private float minXInit;
    //x轴坐标对应的数据
    private List<String> xValue = new ArrayList<>();
    //y轴坐标对应的数据
    private List<Float> yValue = new ArrayList<>();
    //折线对应的数据
    private Map<String, Float> value = new HashMap<>();
    private Map<String, Float> value1 = new HashMap<>();
    //点击的点对应的X轴的第几个点，默认1
    private int selectIndex = 1;
    //X轴刻度文本对应的最大矩形，为了选中时，在x轴文本画的框框大小一致
    private Rect xValueRect;
    //速度检测器
    private VelocityTracker velocityTracker;
    private int widthPixels;

    private scrollToView scrollToView;
    private float startX=2000;

    public void setScrollToView(scrollToView scrollToView){
        this.scrollToView = scrollToView;
    }

    public ChartView(Context context) {
        this(context, null);
    }

    public ChartView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public ChartView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs, defStyleAttr);
        initPaint();

        widthPixels = context.getResources().getDisplayMetrics().widthPixels;

    }
    boolean isStart;
    /**
     * 初始化
     *
     * @param context
     * @param attrs
     * @param defStyleAttr
     */
    private void init(Context context, AttributeSet attrs, int defStyleAttr) {
        TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.chartView, defStyleAttr, 0);
        int count = array.getIndexCount();
        for (int i = 0; i < count; i++) {
            int attr = array.getIndex(i);
            switch (attr) {
                case R.styleable.chartView_xylinecolor://xy坐标轴颜色
                    xylinecolor = array.getColor(attr, xylinecolor);
                    break;
                case R.styleable.chartView_xylinewidth://xy坐标轴宽度
                    xylinewidth = (int) array.getDimension(attr, TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, xylinewidth, getResources().getDisplayMetrics()));
                    break;
                case R.styleable.chartView_xytextcolor://xy坐标轴文字颜色
                    xytextcolor = array.getColor(attr, xytextcolor);
                    break;
                case R.styleable.chartView_xytextsize://xy坐标轴文字大小
                    xytextsize = (int) array.getDimension(attr, TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, xytextsize, getResources().getDisplayMetrics()));
                    break;
                case R.styleable.chartView_linecolor://折线图中折线的颜色
                    linecolor = array.getColor(attr, linecolor);
                    break;
                case R.styleable.chartView_linecolor1://折线图中折线的颜色
                    linecolor1 = array.getColor(attr, linecolor1);
                    break;
                case R.styleable.chartView_interval://x轴各个坐标点水平间距
                    interval = (int) array.getDimension(attr, TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, interval, getResources().getDisplayMetrics()));
                    break;
                case R.styleable.chartView_bgcolor: //背景颜色
                    bgcolor = array.getColor(attr, bgcolor);
                    break;
                case R.styleable.chartView_isScroll://是否在ACTION_UP时，根据速度进行自滑动
                    isScroll = array.getBoolean(attr, isScroll);
                    break;
            }

        }

        array.recycle();

    }

    /**
     * 初始化畫筆
     */
    private void initPaint() {
        xyPaint = new Paint();
        xyPaint.setAntiAlias(true);
        xyPaint.setStrokeWidth(xylinewidth);
        xyPaint.setStrokeCap(Paint.Cap.ROUND);
        xyPaint.setColor(xylinecolor);

        xyTextPaint = new Paint();
        xyTextPaint.setAntiAlias(true);
        xyTextPaint.setTextSize(xytextsize);
        xyTextPaint.setStrokeCap(Paint.Cap.ROUND);
        xyTextPaint.setColor(xytextcolor);
        xyTextPaint.setStyle(Paint.Style.STROKE);

        <