Android实现列表时间轴

public class DividerItemDecoration extends RecyclerView.ItemDecoration{
// 写右边字的画笔(具体信息)
private Paint mPaint;
// 写左边日期字的画笔( 时间 + 日期)
private Paint mPaint1;
private Paint mPaint2;
private Paint mPaint3;
// 左 上偏移长度
private int itemView_leftinterval;
private int itemView_topinterval;
// 轴点半径
private int circle_radius;
// 图标
private Bitmap mIcon;
//月份合集(使用时需要设置)
private List<String  monthList= new ArrayList< ();
//年份合集(使用时需要设置)
private List<String  yearList= new ArrayList< ();
public void setMonthList(List<String  monthList) {
this.monthList = monthList;
}
public void setYearList(List<String  yearList) {
this.yearList = yearList;
}
// 在构造函数里进行绘制的初始化，如画笔属性设置等
public DividerItemDecoration(Context context) {
// 轴点画笔(红色)
mPaint = new Paint();
mPaint.setColor(Color.rgb(58, 154, 239));
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(3);
// 左边时间文本画笔(蓝色)
// 此处设置了两只分别设置 时分 & 年月
mPaint1 = new Paint();
mPaint1.setColor(Color.BLACK);
mPaint1.setTextSize(30);
mPaint2 = new Paint();
mPaint2.setColor(context.getResources().getColor(R.color.divider));
mPaint2.setTextSize(26);
mPaint3 = new Paint();
mPaint3.setColor(Color.rgb(58, 154, 239));
mPaint3.setTextSize(20);
// 赋值ItemView的左偏移长
itemView_leftinterval = 150;
// 赋值ItemView的上偏移长度
itemView_topinterval = 30;
// 赋值轴点圆的半径为10
circle_radius = 8;
}
// 重写getItemOffsets（）方法
// 作用：设置ItemView 左 & 上偏移长度
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
super.getItemOffsets(outRect, view, parent, state);
// 设置ItemView的左 & 上偏移长度分别为150 px & 30px,即此为onDraw()可绘制的区域
outRect.set(itemView_leftinterval, itemView_topinterval, 0, 0);
}
// 重写onDraw（）
// 作用:在间隔区域里绘制时光轴线 & 时间文本
@Override
public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
super.onDraw(c, parent, state);
// 获取RecyclerView的Child view的个数
int childCount = parent.getChildCount();
// 遍历每个Item，分别获取它们的位置信息，然后再绘制对应的分割线
for (int i = 0; i < childCount; i++) {
// 获取每个Item对象
View child = parent.getChildAt(i);
View lastChild = null;
if (i   0) {
lastChild = parent.getChildAt(i - 1);
}
/**
* 绘制轴点
*/
// 轴点 = 圆 = 圆心(x,y) 位置可以根据需求来调节
float centerx = child.getLeft() - itemView_leftinterval / 4;
float centery = child.getTop() + itemView_topinterval +10;
// 绘制轴点圆
c.drawCircle(centerx, centery, circle_radius, mPaint);
/**
* 绘制上半轴线(x轴是保持不变的)
*/
// 上端点坐标(x,y)
float upLine_up_x = centerx;
float upLine_up_y = 0;
if (i 0){
upLine_up_y = lastChild.getBottom();
}else {
upLine_up_y = centery - itemView_topinterval;
}
// 下端点坐标(x,y)
float upLine_bottom_x = centerx;
float upLine_bottom_y = centery - circle_radius;
//绘制上半部轴线
c.drawLine(upLine_up_x, upLine_up_y, upLine_bottom_x, upLine_bottom_y, mPaint);
/**
* 绘制下半轴线,最后一个不画下半轴
*/
if (i <childCount-1){
// 上端点坐标(x,y)
float bottomLine_up_x = centerx;
float bottom_up_y = centery + circle_radius;
// 下端点坐标(x,y)
float bottomLine_bottom_x = centerx;
float bottomLine_bottom_y = child.getBottom();
//绘制下半部轴线
c.drawLine(bottomLine_up_x, bottom_up_y, bottomLine_bottom_x, bottomLine_bottom_y, mPaint);
}
/**
* 绘制左边时间文本
*/
// 获取每个Item的位置
int index = parent.getChildAdapterPosition(child);
// 设置文本起始坐标
float Text_x = child.getLeft() - itemView_leftinterval * 5 / 6;
float Text_y = upLine_bottom_y;
// 根据Item位置设置时间文本
switch (index) {
case (0):
// 设置日期绘制位置
c.drawText(monthList.get(0), Text_x, Text_y, mPaint1);
c.drawText(yearList.get(0), Text_x + 8, Text_y + 28, mPaint2);
break;
case (1):
// 设置日期绘制位置
c.drawText(monthList.get(1), Text_x, Text_y, mPaint1);
c.drawText(yearList.get(1), Text_x + 8, Text_y + 28, mPaint2);
break;
case (2):
// 设置日期绘制位置
if (TextUtils.isEmpty(yearList.get(2))){
c.drawText(monthList.get(2), Text_x, Text_y, mPaint3);
}else {
c.drawText(monthList.get(2), Text_x, Text_y, mPaint1);
c.drawText(yearList.get(2), Text_x + 8, Text_y + 28, mPaint2);
}
break;
case (3):
// 设置日期绘制位置
c.drawText(monthList.get(3), Text_x, Text_y, mPaint1);
c.drawText(yearList.get(3), Text_x + 8, Text_y + 28, mPaint2);
break;
case (4):
// 设置日期绘制位置
c.drawText(monthList.get(4), Text_x, Text_y, mPaint1);
c.drawText(yearList.get(4), Text_x + 8, Text_y + 28, mPaint2);
break;
default:c.drawText("结束", Text_x, Text_y, mPaint1);
}
}
}
}

DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(this);
dividerItemDecoration.setMonthList(monthList);
dividerItemDecoration.setYearList(yearList);
mRecyclerView.addItemDecoration(dividerItemDecoration);