Android自定义控件实现可多选课程日历CalendarView

package widget;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.MotionEvent;
import android.view.View;

import com.arisaid.calendarview.R;

import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;

/**
 * Created by zhouyou on 2016/7/25.
 * Class desc:
 *
 * 自定义日历View，可多选
 */
public class CalendarView extends View {

  // 列的数量
  private static final int NUM_COLUMNS  =  7;
  // 行的数量
  private static final int NUM_ROWS    =  6;

  /**
   * 可选日期数据
   */
  private List<String> mOptionalDates;

  /**
   * 以选日期数据
   */
  private List<String> mSelectedDates = new ArrayList<>();

  // 背景颜色
  private int mBgColor = Color.parseColor("#F7F7F7");
  // 天数默认颜色
  private int mDayNormalColor = Color.parseColor("#0070F8");
  // 天数不可选颜色
  private int mDayNotOptColor = Color.parseColor("#CBCBCB");
  // 天数选择后颜色
  private int mDayPressedColor = Color.WHITE;
  // 天数字体大小
  private int mDayTextSize = 14;
  // 是否可以被点击状态
  private boolean mClickable = true;

  private DisplayMetrics mMetrics;
  private Paint mPaint;
  private int mCurYear;
  private int mCurMonth;
  private int mCurDate;

  private int mSelYear;
  private int mSelMonth;
  private int mSelDate;
  private int mColumnSize;
  private int mRowSize;
  private int[][] mDays;

  // 当月一共有多少天
  private int mMonthDays;
  // 当月第一天位于周几
  private int mWeekNumber;
  // 已选中背景Bitmap
  private Bitmap mBgOptBitmap;
  // 未选中背景Bitmap
  private Bitmap mBgNotOptBitmap;

  public CalendarView(Context context) {
    super(context);
    init();
  }

  public CalendarView(Context context, AttributeSet attrs) {
    super(context, attrs);
    init();
  }

  public CalendarView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    init();
  }

  private void init() {
    // 获取手机屏幕参数
    mMetrics = getResources().getDisplayMetrics();
    // 创建画笔
    mPaint = new Paint();
    // 获取当前日期
    Calendar calendar = Calendar.getInstance();
    mCurYear  =  calendar.get(Calendar.YEAR);
    mCurMonth  =  calendar.get(Calendar.MONTH);
    mCurDate  =  calendar.get(Calendar.DATE);
    setSelYTD(mCurYear, mCurMonth, mCurDate);

    // 获取背景Bitmap
    mBgOptBitmap  = BitmapFactory.decodeResource(getResources(), R.mipmap.ic_bg_course_optional);
    mBgNotOptBitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.ic_bg_course_not_optional);
  }

  @Override
  public void invalidate() {
    // 避免程序过度绘制
    if(hasWindowFocus()) super.invalidate();
  }

  @Override
  protected void onDraw(Canvas canvas) {
    initSize();

    // 绘制背景
    mPaint.setColor(mBgColor);
    canvas.drawRect(0, 0, canvas.getWidth(), canvas.getHeight(), mPaint);

    mDays = new int[6][7];
    // 设置绘制字体大小
    mPaint.setTextSize(mDayTextSize * mMetrics.scaledDensity);
    // 设置绘制字体颜色

    String dayStr;
    // 获取当月一共有多少天
    mMonthDays = DateUtils.getMonthDays(mSelYear, mSelMonth);
    // 获取当月第一天位于周几
    mWeekNumber = DateUtils.getFirstDayWeek(mSelYear, mSelMonth);

    for(int day = 0; day < mMonthDays; day++){
      dayStr = String.valueOf(day + 1);
      int column = (day + mWeekNumber - 1) % 7;
      int row   = (day + mWeekNumber - 1) / 7;
      mDays[row][column] = day + 1;
      int startX = (int) (mColumnSize * column + (mColumnSize - mPaint.measureText(dayStr)) / 2);
      int startY = (int) (mRowSize * row + mRowSize / 2 - (mPaint.ascent() + mPaint.descent()) / 2);

      // 判断当前天数是否可选
      if(mOptionalDates.contains(getSelData(mSelYear, mSelMonth, mDays[row][column]))){
        // 可选，继续判断是否是点击过的
        if(!mSelectedDates.contains(getSelData(mSelYear, mSelMonth, mDays[row][column]))){
          // 没有点击过，绘制默认背景
          canvas.drawBitmap(mBgNotOptBitmap, startX - 22, startY - 55, mPaint);
          mPaint.setColor(mDayNormalColor);
        }else{
          // 点击过，绘制点击过的背景
          canvas.drawBitmap(mBgOptBitmap, startX - 22, startY - 55, mPaint);
          mPaint.setColor(mDayPressedColor);
        }
        // 绘制天数
        canvas.drawText(dayStr, startX, startY - 10, mPaint);
      }else{
        mPaint.setColor(mDayNotOptColor);
        canvas.drawText(dayStr, startX, startY, mPaint);
      }
    }
  }

  private int downX = 0,downY = 0;

  @Override
  public boolean onTouchEvent(MotionEvent event) {
    int eventCode = event.getAction();
    switch(eventCode){
      case MotionEvent.ACTION_DOWN:
        downX = (int) event.getX();
        downY = (int) event.getY();
        break;
      case MotionEvent.ACTION_MOVE:
        break;
      case MotionEvent.ACTION_UP:
        if(!mClickable) return true;

        int upX = (int) event.getX();
        int upY = (int) event.getY();
        if(Math.abs(upX - downX) < 10 && Math.abs(upY - downY) < 10){
          performClick();
          onClick((upX + downX) / 2, (upY + downY) / 2);
        }
        break;
    }
    return true;
  }

  /**
   * 点击事件
   */
  private void onClick(int x, int y){
    int row = y / mRowSize;
    int column = x / mColumnSize;
    setSelYTD(mSelYear, mSelMonth, mDays[row][column]);

    // 判断是否点击过
    boolean isSelected = mSelectedDates.contains(getSelData(mSelYear, mSelMonth, mSelDate));
    if(isSelected){
      mSelectedDates.remove(getSelData(mSelYear, mSelMonth, mSelDate));
    }else{
      mSelectedDates.add(getSelData(mSelYear, mSelMonth, mSelDate));
    }

    invalidate();
    if(mListener != null){
      // 执行回调
      mListener.onClickDateListener(mSelYear, (mSelMonth + 1), mSelDate);
    }
  }

  /**
   * 初始化列宽和高
   */
  private void initSize() {
    // 初始化每列的大小
    mColumnSize = getWidth() / NUM_COLUMNS;
    // 初始化每行的大小
    mRowSize = getHeight() / NUM_ROWS;
  }

  /**
   * 设置可选择日期
   * @param dates 日期数据
   */
  public void setOptionalDate(List<String> dates){
    this.mOptionalDates = dates;
  }

  /**
   * 设置年月日
   * @param year 年
   * @param month 月
   * @param date 日
   */
  public void setSelYTD(int year, int month, int date){
    this.mSelYear  =  year;
    this.mSelMonth =  month;
    this.mSelDate  =  date;
  }

  /**
   * 设置上一个月日历
   */
  public void setLastMonth(){
    int year  =  mSelYear;
    int month  =  mSelMonth;
    int day   =  mSelDate;
    // 如果是1月份，则变成12月份
    if(month == 0){
      year = mSelYear-1;
      month = 11;
    }else if(DateUtils.getMonthDays(year, month) == day){
      //　如果当前日期为该月最后一点，当向前推的时候，就需要改变选中的日期
      month = month-1;
      day = DateUtils.getMonthDays(year, month);
    }else{
      month = month-1;
    }
    setSelYTD(year,month,day);
    invalidate();
  }

  /**
   * 设置下一个日历
   */
  public void setNextMonth(){
    int year  =  mSelYear;
    int month  =  mSelMonth;
    int day   =  mSelDate;
    // 如果是12月份，则变成1月份
    if(month == 11){
      year = mSelYear+1;
      month = 0;
    }else if(DateUtils.getMonthDays(year, month) == day){
      //　如果当前日期为该月最后一点，当向前推的时候，就需要改变选中的日期
      month = month + 1;
      day = DateUtils.getMonthDays(year, month);
    }else{
      month = month + 1;
    }
    setSelYTD(year,month,day);
    invalidate();
  }

  /**
   * 获取当前展示的年和月份
   * @return 格式：2016-06
   */
  public String getDate(){
    String data;
    if((mSelMonth + 1) < 10){
      data = mSelYear + "-0" + (mSelMonth + 1);
    }else{
      data = mSelYear + "-" + (mSelMonth + 1);
    }
    return data;
  }

  /**
   * 获取当前展示的日期
   * @return 格式：20160606
   */
  private String getSelData(int year, int month, int date){
    String monty, day;
    month = (month + 1);

    // 判断月份是否有非0情况
    if((month) < 10) {
      monty = "0" + month;
    }else{
      monty = String.valueOf(month);
    }

    // 判断天数是否有非0情况
    if((date) < 10){
      day = "0" + (date);
    }else{
      day = String.valueOf(date);
    }
    return year + monty + day;
  }

  /**
   * 获取已选日期数据
   */
  public List<String> getSelectedDates(){
    return mSelectedDates;
  }

  /**
   * 设置已选日期数据
   */
  public void setSelectedDates(List<String> dates){
    this.mSelectedDates = dates;
  }

  /**
   * 设置日历是否可以点击
   */
  @Override
  public void setClickable(boolean clickable) {
    this.mClickable = clickable;
  }

  private OnClickListener mListener;

  public interface OnClickListener{
    void onClickDateListener(int year, int month, int day);
  }

  /**
   * 设置点击回调
   */
  public void setOnClickDate(OnClickListener listener){
    this.mListener = listener;
  }

  @Override
  protected void onDetachedFromWindow() {
    super.onDetachedFromWindow();
    recyclerBitmap(mBgOptBitmap);
    recyclerBitmap(mBgNotOptBitmap);
  }

  /**
   * 释放Bitmap资源
   */
  private void recyclerBitmap(Bitmap bitmap) {
    if(bitmap != null && !bitmap.isRecycled()){
      bitmap.recycle();
    }
  }
}

List<String> mDatas = new ArrayList<>();
mDatas.add("20160801");
mDatas.add("20160802");
mDatas.add("20160803");
mDatas.add("20160816");
mDatas.add("20160817");
mDatas.add("20160826");
mDatas.add("20160910");
mDatas.add("20160911");
mDatas.add("20160912");

// 设置可选日期
mCalendarView.setOptionalDate(mDatas);

mCalendarView.setOnClickDate(new CalendarView.OnClickListener() {
  @Override
  public void onClickDateListener(int year, int month, int day) {
    Toast.makeText(getApplication(), year + "年" + month + "月" + day + "天", Toast.LENGTH_SHORT).show();

    // 获取已选择日期
    List<String> dates = mCalendarView.getSelectedDates();
    for (String date : dates) {
      Log.e("test", "date: " + date);
    }

  }
});

// 设置已选日期
mCalendarView.setSelectedDates(mDatas);
// 设置不可以被点击
mCalendarView.setClickable(false);