Android实现短信验证码输入框

open class ListenPasteEditTextTest : AppCompatEditText {

    constructor(context: Context): super(context)
    constructor(context: Context, attributeSet: AttributeSet): super(context,attributeSet)
    constructor(context: Context, attributeSet: AttributeSet, defStyleAttr: Int): super(context, attributeSet, defStyleAttr)

    var lisenter: ClipInterface ? = null

    override fun onTextContextMenuItem(id: Int): Boolean {
        when(id) {
            //剪切复制黏贴
            android.R.id.cut -> lisenter?.onCut();
            android.R.id.copy -> lisenter?.onCopy();
            android.R.id.paste -> lisenter?.onPaste();
        }

        return super.onTextContextMenuItem(id)
    }
}

interface ClipInterface{
    fun onCut()
    fun onCopy()
    fun onPaste()
}

class VerificationCodeInputTest(context: Context, attributeSet: AttributeSet) : ViewGroup(context, attributeSet), ClipInterface{

    private val box = 4
    private val boxWidth = 120
    private val boxHeight = 120
    private var childPadding = 14

    private val TYPE_NUMBER = "number"
    private val TYPE_TEXT = "text"
    private val TYPE_PASSWORD = "password"
    private val TYPE_PHONE = "phone"

    private val boxBgFocus: Drawable? = null
    private val boxBgNormal: Drawable? = null

    private val inputType = TYPE_NUMBER
    var listener: VerCideListener? = null

    init {
        val textWatcher = object : TextWatcher{
            override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {

            }

            override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {

            }

            override fun afterTextChanged(s: Editable?) {
                if (s != null) {
                    if (s.isNotEmpty()) {
                        focus()
                        checkAndCommit()
                    }
                }
            }
        }

        val onKeyListener = OnKeyListener { v, keyCode, event ->
            if (keyCode == KeyEvent.KEYCODE_DEL) {
                //backFocus();
                backFocusClearAll()
            }
            false
        }

        //四个输入框
        for (index in 0 until box) {
            val editText = ListenPasteEditTextTest(context)
            val layoutParams = LinearLayout.LayoutParams(boxWidth, boxHeight)
            layoutParams.bottomMargin = childPadding
            layoutParams.topMargin = childPadding
            layoutParams.leftMargin = childPadding
            layoutParams.rightMargin = childPadding
            layoutParams.gravity = Gravity.CENTER
            editText.layoutParams = layoutParams
            editText.lisenter = this
            editText.setOnKeyListener(onKeyListener)
            //设置背景颜色，就是输入框中的下划线
            setBg(editText, false)
            editText.setTextColor(Color.BLACK)
            editText.gravity = Gravity.CENTER
            //最多给你输入一个字符
            editText.filters = arrayOf<InputFilter>(InputFilter.LengthFilter(1))

            //设置textView输入内容的显示模式
            if (TYPE_PASSWORD == inputType) {
                editText.transformationMethod = PasswordTransformationMethod.getInstance()
            } else if (TYPE_TEXT == inputType) {
                editText.inputType = InputType.TYPE_CLASS_TEXT
            } else if (TYPE_PHONE == inputType) {
                editText.inputType = InputType.TYPE_CLASS_PHONE
            }

            editText.id = index
            //设置字符宽度
            editText.setEms(1)
            editText.addTextChangedListener(textWatcher)
            addView(editText, index)
        }
    }

    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
        var parentWidth = measuredWidth
        //如果在xml中配置的是match_patent 则直接获取当前手机的width尺寸
        if (parentWidth == ViewGroup.LayoutParams.MATCH_PARENT) {
            parentWidth = getScreenWidth()
        }
        Log.d(javaClass.name, "onMeasure width $parentWidth")

        val count = childCount
        for (i in 0 until count) {
            val child = getChildAt(i)
            this.measureChild(child, widthMeasureSpec, heightMeasureSpec)
        }
        if (count > 0) {
            val child = getChildAt(0)
            val cWidth = child.measuredWidth
            if (parentWidth != ViewGroup.LayoutParams.WRAP_CONTENT) {
                // 重新计算padding
                childPadding = (parentWidth - cWidth * count) / (count + 1)
            }

            val cHeight = child.measuredHeight

            val maxH = cHeight + 2 * childPadding
            val maxW = cWidth * count + childPadding * (count + 1)
            //上面都是计算当前editText的width加上pandding，之后设置给父布局
            setMeasuredDimension(
                View.resolveSize(maxW, widthMeasureSpec),
                View.resolveSize(maxH, heightMeasureSpec)
            )
        }
    }

    override fun onLayout(changed: Boolean, l: Int, t: Int, r: Int, b: Int) {
        val childCount = childCount

        for (i in 0 until childCount) {
            val child = getChildAt(i)
            child.visibility = View.VISIBLE
            val cWidth = child.measuredWidth
            val cHeight = child.measuredHeight
            val cl = childPadding + i * (cWidth + childPadding)
            val cr = cl + cWidth
            val ct = childPadding
            val cb = ct + cHeight
            child.layout(cl, ct, cr, cb)
        }
    }

    private fun getScreenWidth(): Int {
        val resources = this.resources
        val dm = resources.displayMetrics
        return dm.widthPixels
    }

    override fun onCut() {

    }

    override fun onCopy() {

    }

    override fun onPaste() {
        val copyText = getCutAndCopyText()
        // 如果是数字并且 length 和 填写位数一致才会进行填充
        if (isNumeric(copyText) && copyText.length == box) {
            for (i in 0 until childCount) {
                (getChildAt(i) as EditText).append(copyText.get(i).toString())
            }
        }
    }

    fun setBg(editText: EditText, focus: Boolean) {
        if (boxBgNormal != null && !focus) {
            editText.background = boxBgNormal
        } else if (boxBgFocus != null && focus) {
            editText.background = boxBgFocus
        }
    }

    private fun focus() {
        val count = childCount
        var editText: EditText
        for (i in 0 until count) {
            editText = getChildAt(i) as EditText
            if (editText.text.isEmpty()) {
                editText.requestFocus()
                return
            }
        }
    }

    private fun checkAndCommit() {
        val stringBuilder = StringBuilder()
        var full = false
        for (i in 0 until box) {
            val editText = getChildAt(i) as EditText
            val content = editText.text.toString()
            if (!content.isEmpty()) {
                stringBuilder.append(content)
            }
        }

        if (stringBuilder.length == box) {
            full = true
        }

        if (full) {

            if (listener != null) {
                listener?.onComplete(stringBuilder.toString())
                backFocusClearAll()
            }
        }
    }


    //清空所有并重新输入
    fun backFocusClearAll() {
        var editText: EditText
        for (i in 0 until box) {
            editText = getChildAt(i) as EditText
            editText.setText("")
            editText.clearFocus()
        }
        getChildAt(0).requestFocus()
    }

    
    private fun isNumeric(str: String?): Boolean {
        if (str == null || str.isEmpty()) {
            return false
        }
        for (i in 0 until str.length) {
            if (!Character.isDigit(str[i])) {
                return false
            }
        }
        return true
    }

    
    private fun getCutAndCopyText(): String {
        val manager = context.getSystemService(CLIPBOARD_SERVICE) as ClipboardManager
        if (manager != null && manager.hasPrimaryClip() && manager.primaryClip!!.itemCount > 0) {
            val addedText = manager.primaryClip!!.getItemAt(0).text
            if (addedText != null) {
                return addedText.toString()
            }
        }
        return ""
    }
}

interface VerCideListener {
    fun onComplete(content: String)
}