自定义view实战(11)：滑动解锁九宫格控件

前语

上一篇文章用贝塞尔曲线画了一个看起来不错的小红点功用，技术上没什么难度，首要便是数学上的核算。这篇文章也差不多，仿照了一个常用的滑动解锁的九宫格控件。

需求

用过安卓的都知道，用过苹果的也知道，这儿便是一个滑动解锁的控件。中心思想如下：

• 1、摆放九个圆，当手指经过圆邻近的时分选取该点，手指移动的时分将选中点连线
• 2、预设一个正确的连线，当手指抬起时的连线与预设连线一致，验证经过
• 3、经过layout参数能够设置圆和线的色彩

效果图

这儿功用牵强能够吧，感觉选中点的时分不是很流通。

代码

import android.annotation.SuppressLint
import android.content.Context
import android.graphics.Canvas
import android.graphics.Color
import android.graphics.Paint
import android.graphics.Path
import android.util.AttributeSet
import android.view.MotionEvent
import android.view.View
import com.silencefly96.module_common.R
import java.util.*
import kotlin.math.sqrt
/**
 * 九宫格控件
 *
 * @author silence
 * @date 2022-11-09
 */
class PatternLockView @JvmOverloads constructor(
    context: Context,
    attributeSet: AttributeSet? = null,
    defStyleAttr: Int = 0
): View(context, attributeSet, defStyleAttr){
    /**
     * 预设值
     */
    var preData = LinkedList<Int>()
    /**
     * 回调接口
     */
    var listener: OnMoveUpListener? = null
    // 当前值
    private var curData = LinkedList<Int>()
    // 圆的色彩
    private val mCircleColor: Int
    // 线的色彩
    private val mLineColor: Int
    // 圆半径占最短宽高的份额
    private val mRadiusPercent: Float
    // 两点之间的间隔
    private var mBetweenLength = 0f
    // 第一个圆地点位置
    private var mStartX = 0f
    private var mStartY = 0f
    // 圆半径
    private var mRadius = 0f
    // 当前手指地点的位置
    private var mCurPosX = 0f
    private var mCurPosY = 0f
    // 是否在移动的状况
    private var isMoving = false
    // 途径
    private var mPath = Path()
    // 校验成果， -1失利，0未验证，1验证成功，依据验证成果修改线条色彩
    private var mCheckResult = 0
    // 画笔
    private val mPaint = Paint().apply {
        strokeWidth = 5f
        style = Paint.Style.STROKE
        flags = Paint.ANTI_ALIAS_FLAG
        // 连接处样式: 平斜接
        strokeJoin = Paint.Join.MITER
        strokeMiter = 4f
        // 落笔和结束时那点(point)的样式: 增加半圆
        strokeCap = Paint.Cap.ROUND
    }
    init {
        // 获取布局参数
        val typedArray =
            context.obtainStyledAttributes(attributeSet, R.styleable.PatternLockView)
        mCircleColor = typedArray.getColor(R.styleable.PatternLockView_circleColor,
            Color.LTGRAY)
        mLineColor = typedArray.getColor(R.styleable.PatternLockView_lineColor, Color.YELLOW)
        mRadiusPercent = typedArray.getFraction(R.styleable.PatternLockView_circleRadiusPercent,
            1, 1, 0.05f)
        typedArray.recycle()
    }
    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec)
        val width = getDefaultSize(100, widthMeasureSpec)
        val height = getDefaultSize(100, heightMeasureSpec)
        // 设置参数
        mBetweenLength = (if (width < height) width else height) * 0.25f
        mRadius = (if (width < height) width else height) * mRadiusPercent
        mStartX = width / 2f - mBetweenLength
        mStartY = height / 2f - mBetweenLength
        setMeasuredDimension(width, height)
    }
    @SuppressLint("ClickableViewAccessibility")
    override fun onTouchEvent(event: MotionEvent): Boolean {
        when(event.action) {
            MotionEvent.ACTION_DOWN -> {
                // 铲除旧数据
                isMoving = true
                curData.clear()
                mCheckResult = 0
                invalidate()
            }
            MotionEvent.ACTION_MOVE -> {
                // 判别是否进入哪个点的范围
                val index = getEventCircleIndex(event.x, event.y)
                if (index != -1 && !curData.contains(index)) {
                    curData.add(index)
                }
                mCurPosX = event.x
                mCurPosY = event.y
                // 触发制作
                invalidate()
            }
            MotionEvent.ACTION_UP -> {
                isMoving = false
                // 判别是否契合设置的值
                if (curData == preData) {
                    mCheckResult = 1
                    listener?.onMoveUp(true)
                }else {
                    // 没有连线不触发判别
                    if (curData.size > 1) {
                        mCheckResult = -1
                        listener?.onMoveUp(false)
                    }
                }
                // 最终更新下，把移动的那部分线条去掉
                invalidate()
            }
        }
        return true
    }
    private fun getEventCircleIndex(x: Float, y: Float): Int {
        var curX: Float
        var curY: Float
        for (i in 0 until 9) {
            curX = mStartX + mBetweenLength * (i % 3)
            curY = mStartY + mBetweenLength * (i / 3)
            if (getDistance(curX, curY, x, y) <= mRadius) {
                return i
            }
        }
        return -1
    }
    private fun getDistance(x1: Float, y1: Float, x2: Float, y2: Float): Float {
        // 平方和公式
        @Suppress("ReplaceJavaStaticMethodWithKotlinAnalog")
        return sqrt((Math.pow((x1 - x2).toDouble(), 2.0)
                + Math.pow((y1 - y2).toDouble(), 2.0)).toFloat())
    }
    override fun onDraw(canvas: Canvas) {
        super.onDraw(canvas)
        // 先制作九个点
        var curX: Float
        var curY: Float
        mPaint.color = mCircleColor
        mPaint.style = Paint.Style.FILL
        mPaint.strokeWidth = 5f
        for (i in 0 until 9) {
            curX = mStartX + mBetweenLength * (i % 3)
            curY = mStartY + mBetweenLength * (i / 3)
            canvas.drawCircle(curX, curY, mRadius, mPaint)
        }
        // 再制作线，先画固定的线，再画移动中的线
        mPaint.color = when(mCheckResult) {
            -1 -> Color.RED
            1 -> Color.GREEN
            else -> mLineColor
        }
        mPaint.style = Paint.Style.STROKE
        mPaint.strokeWidth = mRadius / 3f
        mPath.reset()
        for (i in curData) {
            // 当前点坐标
            curX = mStartX + mBetweenLength * (i % 3)
            curY = mStartY + mBetweenLength * (i / 3)
            if (curData.indexOf(i) == 0) {
                mPath.moveTo(curX, curY)
            }else {
                mPath.lineTo(curX, curY)
            }
        }
        // 再画最终一点
        if (curData.size > 0 && isMoving) {
            mPath.lineTo(mCurPosX, mCurPosY)
        }
        canvas.drawPath(mPath, mPaint)
    }
    interface OnMoveUpListener{
        fun onMoveUp(success: Boolean)
    }
}

对应的style文件: pattern_lock_view_style.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="PatternLockView">
        <attr name="circleColor" format="color"/>
        <attr name="lineColor" format="color"/>
        <attr name="circleRadiusPercent" format="fraction"/>
    </declare-styleable>
</resources>

首要问题

实际上，这儿没什么有难度的地方，便是画了九个圆，加上几段依据触发的点构成的连线，就不多写了，能够看代码注释。