Amount edittext first version

views/src/main/java/ru/touchin/widget/AmountWithDecimalEditText.kt

@@ -0,0 +1,151 @@
+package ru.touchin.widget
+
+import android.content.Context
+import android.util.AttributeSet
+import androidx.appcompat.widget.AppCompatEditText
+import androidx.core.widget.doOnTextChanged
+import ru.touchin.roboswag.components.views.R
+import java.text.DecimalFormat
+import java.text.DecimalFormatSymbols
+import kotlin.math.max
+import kotlin.math.min
+import kotlin.math.pow
+
+class AmountWithDecimalEditText @JvmOverloads constructor(
+    context: Context,
+    attrs: AttributeSet?,
+    defStyleAttr: Int = R.attr.editTextStyle
+) : AppCompatEditText(context, attrs, defStyleAttr) {
+
+    companion object {
+
+        private const val COMMON_MONEY_MASK = "###,##0"
+        private const val DEFAULT_DECIMAL_SEPARATOR = ","
+        private const val GROUPING_SEPARATOR = ' '
+        private const val DEFAULT_DECIMAL_PART_LENGTH = 2
+        private val hardcodedSymbols = listOf(GROUPING_SEPARATOR)
+        private val possibleDecimalSeparators = listOf(",", ".")
+    }
+
+    private var textBefore = ""
+    private var isTextWasArtificiallyChanged = true
+
+    var decimalSeparator = DEFAULT_DECIMAL_SEPARATOR
+        set(value) {
+            if (!possibleDecimalSeparators.contains(value))
+                throw Exception("Not allowed decimal separator. Supports only: $possibleDecimalSeparators")
+            field = value
+        }
+
+
+    var decimalPartLength = DEFAULT_DECIMAL_PART_LENGTH
+    var isSeparatorCutInvalidDecimalLength = false
+
+    init {
+        doOnTextChanged { text, _, _, _ ->
+            if (isTextWasArtificiallyChanged) {
+                isTextWasArtificiallyChanged = false
+                val cursorPos = selectionStart
+                var text = text.toString()
+                possibleDecimalSeparators.forEach {
+                    text = text.replace(it, decimalSeparator)
+                }
+
+                if (text == decimalSeparator || text.count { it == decimalSeparator[0] } > 1) {
+                    setText(textBefore)
+                    setSelection(max(cursorPos - 1, 0))
+                    return@doOnTextChanged
+                }
+
+                if (text.take(2) == "00") {
+                    setText(textBefore)
+                    setSelection(max(cursorPos - 1, 0))
+                    return@doOnTextChanged
+                }
+
+                if (text.length >= 2 && text[0] == '0' && text[1] != decimalSeparator[0]) {
+                    setText(text[1].toString())
+                    setSelection(max(cursorPos - 1, 0))
+                    return@doOnTextChanged
+                }
+
+
+                val decimalPartLength_ = text.split(decimalSeparator).getOrNull(1)?.length
+                if (!isSeparatorCutInvalidDecimalLength && decimalPartLength_ != null && decimalPartLength_ > decimalPartLength) {
+                    setText(textBefore)
+                    setSelection(max(cursorPos - 1, 0))
+                    return@doOnTextChanged
+                }
+
+                val textAfter = if (text.isNotEmpty()) {
+                    text.withoutFormatting().formatMoney(decimalPartLength_)
+                } else ""
+
+                if (!isTextErased(textBefore, textAfter)) {
+                    val diff = textAfter.length - textBefore.length - 1
+                    setText(textAfter)
+                    setSelection(min(cursorPos + diff, textAfter.length))
+                } else {
+                    if (!textBefore.contains(decimalSeparator)
+                        && textAfter.contains(decimalSeparator)
+                    ) {
+                        setText(textAfter)
+                        setSelection(
+                            min(
+                                textAfter.length,
+                                textAfter.indexOf(decimalSeparator) + 1
+                            )
+                        )
+                        return@doOnTextChanged
+                    }
+                    val diff = textBefore.length - textAfter.length
+                    if (diff == 0) {
+                        setText(textAfter)
+                        setSelection(min(cursorPos, textAfter.length))
+                    } else {
+                        setText(textAfter)
+                        setSelection(max(cursorPos - diff + 1, 0))
+                    }
+
+                }
+            } else {
+                textBefore = text.toString()
+                isTextWasArtificiallyChanged = true
+            }
+        }
+    }
+
+
+    fun getTextWithoutFormatting() = text.toString().withoutFormatting()
+
+    private fun String.withoutFormatting(): String {
+        var result = this
+        hardcodedSymbols.forEach { result = this.replace(it.toString(), "") }
+        return result
+    }
+
+    private fun isTextErased(textBefore: String, textAfter: String) =
+        textAfter.length <= textBefore.length
+
+    private fun String.formatMoney(decimalPartLength_: Int?): String {
+        var mask = COMMON_MONEY_MASK
+        if (decimalPartLength_ != null && decimalPartLength != 0) mask += "." + "0".repeat(
+            min(
+                decimalPartLength_,
+                decimalPartLength
+            )
+        )
+
+        val formatter = DecimalFormat(mask)
+        formatter.decimalFormatSymbols = DecimalFormatSymbols().also {
+            it.decimalSeparator = decimalSeparator[0]
+            it.groupingSeparator = GROUPING_SEPARATOR
+        }
+        return formatter.format(this.replace(",", ".").toDouble().floor())
+    }
+
+    private fun Double.floor() =
+        (this * 10.toDouble().pow(decimalPartLength)).toLong() / 10.toDouble()
+            .pow(decimalPartLength)
+
+}