android 自定义PickerView 日期滑动选择器

 

 

package com.inks.alltest;

import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.LinearGradient;
import android.graphics.Paint;
import android.graphics.RectF;
import android.graphics.Shader;
import android.os.Handler;
import android.os.Message;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;

import java.util.ArrayList;


/**
 * Created by inks on 2019/5/1 0021.
 */

public class RollerPickerView extends View {
    private ArrayList lists = new ArrayList<>();
    private int itemNumber = 3;
    private float textSize = 60;
    private int textUncheckedColour = 0XFF666666;
    private int textSelectionColour = 0XFFFFFFFF;
    private float midTextScale = 0.1f;
    //选中条目背景色
    private int selectedBgMid = 0XFF00c6ff;
    private int selectedBgSides = 0XFF00c6ff;
    //未选中的背景色
    private int unSelectedBgMid = 0XFF00c6ff;
    private int unSelectedBgSides = 0XFF00c6ff;
    //分割线颜色
    private int dividingLineColor = 0XFFFFFFFF;
    //当前选中项
    private int selectIndex = 0;


    private static String TAG = "RollerPickerView";
    private Paint mPaint;//文字画笔
    private Paint mLinePaint;//分割线画笔
    private Paint mbgPaint;//背景画笔
    private float oneItemHeight;
    private int specWidthSize, specHeightSize;
    private GradualColourUtil gradualColourUtil;
    private float lastMoveY = 0;
    private float moveY = 0;
    private VelocityTracker velocityTracker;
    private float yVelocity = 0;
    private boolean actionDown = false;
    private boolean needBack = false;

    //上边条目区域
    private RectF unS1;
    //下边条目区域
    private RectF unS2;
    //选中条目区域
    private RectF unS;
    //着色器
    private Shader shader1;
    private Shader shader2;
    private Shader shaderMid;


    //定义一个接口对象listerner
    private OnItemSelectListener listener;

    //获得接口对象的方法。
    public void setOnItemSelectListener(OnItemSelectListener listener) {
        this.listener = listener;
    }
    //定义一个接口
    public interface OnItemSelectListener {
        public void onItemSelect(int index, String indexString);
    }
    public RollerPickerView(Context context) {
        this(context, null);
    }

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

    public RollerPickerView(Context context, AttributeSet attrs, int defStyleAttr) {
        this(context, attrs, defStyleAttr, 0);
    }

    public RollerPickerView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        init();

    }

    public void init() {
        gradualColourUtil = new GradualColourUtil(textUncheckedColour, textSelectionColour);
        mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mPaint.setTextAlign(Paint.Align.CENTER);
        mLinePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mLinePaint.setColor(dividingLineColor);
        mLinePaint.setStrokeWidth(4);
        mbgPaint = new Paint(Paint.ANTI_ALIAS_FLAG);

        if (velocityTracker == null) {//velocityTracker对象为空 获取velocityTracker对象
            velocityTracker = VelocityTracker.obtain();
        } else {//velocityTracker对象不为空 将velocityTracker对象重置为初始状态
            velocityTracker.clear();
        }
        lists.clear();
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        specWidthSize = MeasureSpec.getSize(widthMeasureSpec);//宽
        specHeightSize = MeasureSpec.getSize(heightMeasureSpec);//高
        oneItemHeight = specHeightSize / (float) itemNumber;
        setMeasuredDimension(specWidthSize, specHeightSize);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        if (moveY == 0) {
            if (Math.abs(lastMoveY) > oneItemHeight / 2) {
                if (lastMoveY > 0) {
                    selectIndex++;
                } else {
                    selectIndex--;
                }
            }
            lastMoveY = 0;
            if (!actionDown) {
                int selectItemIndex;
                if (lists.size() > 0) {
                    if (selectIndex > 0) {
                        selectItemIndex = -selectIndex + (1 - (-selectIndex + 1) / lists.size()) * lists.size();
                    } else {
                        selectItemIndex = -selectIndex + selectIndex / lists.size() * lists.size();
                    }
                    if (listener != null) {
                        if (needBack) {
                            listener.onItemSelect(selectItemIndex, lists.get(selectItemIndex));
                            needBack = false;
                        }
                    }
                }
            }
        } else {
            lastMoveY = lastMoveY + moveY;
            moveY =0;
            if (Math.abs(lastMoveY) >= oneItemHeight) {
                if (lastMoveY > 0) {
                    lastMoveY = lastMoveY - oneItemHeight;
                    selectIndex++;
                } else {
                    lastMoveY = lastMoveY + oneItemHeight;
                    selectIndex--;
                }
            }
        }
        if (unS1 == null || unS == null || unS2 == null) {
            unS1 = new RectF(0, 0, specWidthSize, (itemNumber - 1) / 2 * oneItemHeight);
            unS = new RectF(0, (itemNumber - 1) / 2 * oneItemHeight, specWidthSize, (itemNumber + 1) / 2 * oneItemHeight);
            unS2 = new RectF(0, (itemNumber + 1) / 2 * oneItemHeight, specWidthSize, specHeightSize);
        }
        if (shader1 == null || shader2 == null || shaderMid == null) {
            shader1 = new LinearGradient(0, 0, 0, (itemNumber - 1) / 2 * oneItemHeight, unSelectedBgSides, unSelectedBgMid, Shader.TileMode.REPEAT);
            shader2 = new LinearGradient(0, (itemNumber + 1) / 2 * oneItemHeight, 0, specHeightSize, unSelectedBgMid, unSelectedBgSides, Shader.TileMode.REPEAT);
            shaderMid = new LinearGradient(0, (itemNumber - 1) / 2 * oneItemHeight, 0, (itemNumber + 1) / 2 * oneItemHeight, new int[]{selectedBgSides, selectedBgMid, selectedBgSides}, null, Shader.TileMode.REPEAT);
        }
        mbgPaint.setShader(shader1);
        canvas.drawRect(unS1, mbgPaint);
        mbgPaint.setShader(shader2);
        canvas.drawRect(unS2, mbgPaint);
        mbgPaint.setShader(shaderMid);
        canvas.drawRect(unS, mbgPaint);

        canvas.drawLine(0, (itemNumber - 1) / 2 * oneItemHeight, specWidthSize, (itemNumber - 1) / 2 * oneItemHeight, mLinePaint);
        canvas.drawLine(0, (itemNumber + 1) / 2 * oneItemHeight, specWidthSize, (itemNumber + 1) / 2 * oneItemHeight, mLinePaint);

        //text到中心的最远距离（隐藏到中心）
        float furthest = (itemNumber + 1) / 2.0f * oneItemHeight;
        float midDistance = (itemNumber / 2.0f * oneItemHeight);

        for (int i = -1; i < itemNumber + 1; i++) {
            float baseline = oneItemHeight / 2.0f + oneItemHeight * i + lastMoveY;
            //当前距离中心距离
            float nowDistance = Math.abs(baseline - midDistance);
            //当前距离中心距离百分比
            float nowDisPer = nowDistance / furthest;
            int alpha = 255 - (int) (nowDisPer * 255);
            float scale = midTextScale * nowDisPer;
            if (nowDistance < oneItemHeight) {
                if (nowDistance < (oneItemHeight * 0.8)) {
                    mPaint.setTextSize(textSize * ((1.0f + midTextScale - scale)));
                } else {
                    mPaint.setTextSize(textSize);
                }
                mPaint.setColor(gradualColourUtil.getColour(1 - (nowDistance / oneItemHeight)));
            } else {
                mPaint.setTextSize(textSize);
                mPaint.setColor(textUncheckedColour);
            }
            mPaint.setAlpha(alpha);
            //mPaint.setTextSize(textSize*(1.0f+0.6f-scale)+textSize*(0.6f-scale)*0.5f);
            //mPaint.setTextScaleX(1.0f+scale);
            Paint.FontMetrics fontMetrics = mPaint.getFontMetrics();
            float distance = (fontMetrics.bottom - fontMetrics.top) / 2.0f - fontMetrics.bottom;
            String text;
            if (lists.size() > 1) {
                if (i < ((itemNumber - 1) / 2)) {
                    //距离中间条目的个数（上）
                    int x = (((itemNumber - 1) / 2) - i) + selectIndex;

                    if (x <= 0) {
                        int x2 = -x % lists.size();
                        text = lists.get(x2);
                    } else {
                        //绝对个数
                        int x2 = (x - ((x - 1) / lists.size()) * lists.size());
                        text = lists.get((lists.size() - x2));
                    }

                } else {
                    //距离中间条目的个数（下）
                    int x = (i - ((itemNumber - 1) / 2)) - selectIndex;
                    if (x < 0) {
                        int x2 = lists.size() - ((-x) - ((-x) - 1) / lists.size() * lists.size());
                        text = lists.get((x2));
                    } else {
                        //绝对个数
                        int x2 = x % lists.size();
                        text = lists.get(x2);
                    }

                }
            } else if (lists.size() == 1) {
                text = lists.get(0);
            } else {
                text = "Empty";
            }
            canvas.drawText(text, specWidthSize / 2.0f, baseline + distance, mPaint);
        }
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        velocityTracker.addMovement(event);//向velocityTracker对象添加action
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                actionDown = true;
                mHandler.removeMessages(111);
                moveY = 0;
                invalidate();
                break;
            case MotionEvent.ACTION_UP:
                actionDown = false;
                velocityTracker.computeCurrentVelocity(1000, 2500);
                yVelocity = velocityTracker.getYVelocity();
                mHandler.removeMessages(111);
                mHandler.sendEmptyMessageDelayed(111, 30);
                break;
            case MotionEvent.ACTION_MOVE:
                velocityTracker.computeCurrentVelocity(1000, 2500);
                moveY = velocityTracker.getYVelocity() / 100;
                if (moveY != 0) {
                    invalidate();
                }
                break;
        }
        return true;
    }


    @SuppressLint("HandlerLeak")
    private Handler mHandler = new Handler() {

        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            switch (msg.what) {
                case 111:
                    if (yVelocity >= 100) {
                        yVelocity = yVelocity - 50;
                    } else if (yVelocity <= -50) {
                        yVelocity = yVelocity + 50;
                    } else {
                        yVelocity = 0;
                    }
                    moveY = yVelocity / 100;
                    needBack = true;
                    invalidate();
                    mHandler.removeMessages(111);
                    if (moveY != 0) {
                        mHandler.sendEmptyMessageDelayed(111, 20);
                    }

                    break;
                case 222:

                    break;
            }
        }
    };

    @Override
    protected void onDetachedFromWindow() {
        velocityTracker.recycle();
        super.onDetachedFromWindow();
    }


    public ArrayList getLists() {
        return lists;
    }

    public void setLists(ArrayList lists) {
        mHandler.removeMessages(111);
        this.lists = lists;
        lastMoveY = 0;
        moveY = 0;
        needBack = false;
        selectIndex=0;
        invalidate();
    }

    public int getItemNumber() {
        return itemNumber;
    }

    public void setItemNumber(int itemNumber) {
        mHandler.removeMessages(111);
        lastMoveY = 0;
        moveY = 0;
        needBack = false;
        if(itemNumber>0){
            if(itemNumber%2==0){
                this.itemNumber = itemNumber+1;
            }else{
                this.itemNumber = itemNumber;
            }
            shader1=null;
            unS1=null;
            oneItemHeight = specHeightSize / (float) this.itemNumber;
            Log.e("itemNumber:",this.itemNumber+"");
            invalidate();
        }
    }

    public float getTextSize() {
        return textSize;
    }

    public void setTextSize(float textSize) {
        this.textSize = textSize;
        invalidate();
    }

    public int getTextUncheckedColour() {
        return textUncheckedColour;
    }

    public void setTextUncheckedColour(int textUncheckedColour) {
        this.textUncheckedColour = textUncheckedColour;
        invalidate();
    }

    public int getTextSelectionColour() {
        return textSelectionColour;
    }

    public void setTextSelectionColour(int textSelectionColour) {
        this.textSelectionColour = textSelectionColour;
        invalidate();
    }

    public float getMidTextScale() {
        return midTextScale;
    }

    public void setMidTextScale(float midTextScale) {
        this.midTextScale = midTextScale;
        invalidate();
    }

    public int getSelectedBgMid() {
        return selectedBgMid;
    }

    public void setSelectedBgMid(int selectedBgMid) {
        this.selectedBgMid = selectedBgMid;
        shaderMid=null;
        invalidate();
    }

    public int getSelectedBgSides() {
        return selectedBgSides;
    }

    public void setSelectedBgSides(int selectedBgSides) {
        this.selectedBgSides = selectedBgSides;
        shaderMid=null;
        invalidate();
    }

    public int getUnSelectedBgMid() {
        return unSelectedBgMid;
    }

    public void setUnSelectedBgMid(int unSelectedBgMid) {
        this.unSelectedBgMid = unSelectedBgMid;
        shader1=null;
        shader2=null;
        invalidate();
    }

    public int getUnSelectedBgSides() {
        return unSelectedBgSides;
    }

    public void setUnSelectedBgSides(int unSelectedBgSides) {
        this.unSelectedBgSides = unSelectedBgSides;
        shader1=null;
        shader2=null;
        invalidate();
    }

    public int getDividingLineColor() {
        return dividingLineColor;

    }

    public void setDividingLineColor(int dividingLineColor) {
        this.dividingLineColor = dividingLineColor;
        invalidate();
    }

    public int getSelectIndex() {
        int selectItemIndex;
        if (selectIndex > 0) {
            selectItemIndex = -selectIndex + (1 - (-selectIndex + 1) / lists.size()) * lists.size();
        } else {
            selectItemIndex = -selectIndex + selectIndex / lists.size() * lists.size();
        }
        return selectItemIndex;
    }

    public void setSelectIndex(int selectIndex) {
        this.selectIndex = -selectIndex;
        mHandler.removeMessages(111);
        lastMoveY = 0;
        moveY = 0;
        needBack = false;
        invalidate();
    }
}

 

 

package com.inks.alltest;

public class GradualColourUtil {
    private int startColour;
    private int endColour;

    public GradualColourUtil(int startColour, int endColour) {
        this.startColour = startColour;
        this.endColour = endColour;
    }

    public int getColour(float per) {
        int R = (int) ((endColour - startColour) / 65536 % 256 * per);
        int G = (int) ((endColour - startColour) / 256 % 256 * per);
        int B = (int) ((endColour - startColour) % 256 * per);
        int returnR = startColour / 65536 + R;
        int returnG = startColour / 256 % 256 + G;
        int returnB = startColour % 256 + B;
        return returnR * 65536 + returnG * 256 + returnB +0XFF000000;
    }
}

 

 

 

 

data_bg.xml

 

package com.inks.alltest;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    RollerPickerView pickerView1 ;
    RollerPickerView pickerView2;
    TextView textView;
    private ArrayList years = new ArrayList<>();
    private ArrayList months = new ArrayList<>();
    private String yearStr,monthStr;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_roller);
         pickerView1 = findViewById(R.id.RollerPickerView1);
         pickerView2 = findViewById(R.id.RollerPickerView2);
        textView = findViewById(R.id.TextView);
        initDate();
        pickerView1.setLists(years);
        pickerView2.setLists(months);
        pickerView1.setSelectIndex(29);
        yearStr = "1990";
        monthStr="1";
        textView.setText(yearStr+"-"+monthStr);
        pickerView1.setOnItemSelectListener(new RollerPickerView.OnItemSelectListener() {
            @Override
            public void onItemSelect(int index, String indexString) {
                yearStr = indexString;
                textView.setText(yearStr+"-"+monthStr);
            }
        });
        pickerView2.setOnItemSelectListener(new RollerPickerView.OnItemSelectListener() {
            @Override
            public void onItemSelect(int index, String indexString) {
                monthStr = indexString;
                textView.setText(yearStr+"-"+monthStr);
            }
        });


    }



    private void initDate() {
        years.clear();
        months.clear();
        for(int i =0;i<100;i++){
            years.add((2019-i)+"");
        }
        for(int i =0;i<12;i++){
            months.add((i+1)+"");
        }
    }
}