Updated on 2026-08-14

app/src/main/java/com/tangem/tap/common/text/Truncate.kt

@@ -0,0 +1,136 @@
+package com.tangem.tap.common.text
+
+import android.widget.TextView
+import com.tangem.tap.common.extensions.isEven
+
+/**
+[REDACTED_AUTHOR]
+ */
+enum class TruncateType {
+    START, MIDDLE, END
+}
+
+interface Truncate {
+    fun apply(tv: TextView, text: String, with: String): String
+
+    companion object {
+        fun create(type: TruncateType): Truncate {
+            return when (type) {
+              TruncateType.START -> TruncateStart()
+              TruncateType.MIDDLE -> TruncateMiddle()
+              TruncateType.END -> TruncateEnd()
+            }
+        }
+    }
+}
+
+abstract class BaseTruncate : Truncate {
+    protected var hasBeenTruncated = false
+
+    override fun apply(tv: TextView, text: String, with: String): String {
+        val roughLength = getRoughFitLength(tv, text, with)
+        val fittedText = preciseFitting(tv, roughTruncate(text, roughLength), with)
+        return if (hasBeenTruncated) attachWith(fittedText, with) else fittedText
+    }
+
+    protected fun getRoughFitLength(tv: TextView, text: String, with: String): Int {
+        val existingSpace = tv.measuredWidth - (tv.paddingStart + tv.paddingEnd)
+        val textWillTakeSpace = tv.paint.measureText(text)
+        val overSizeRatio: Float = textWillTakeSpace / existingSpace
+
+        val maxLengthOfText = text.length / overSizeRatio
+        if (text.length <= maxLengthOfText) return text.length
+
+        return maxLengthOfText.toInt()
+    }
+
+    protected fun preciseFitting(tv: TextView, text: String, with: String): String {
+        if (!hasBeenTruncated) return text
+
+        val spaceForText = tv.measuredWidth - (tv.paddingStart + tv.paddingEnd)
+
+        var fittedText = text
+        while (tv.paint.measureText(fittedText + with) > spaceForText) {
+            fittedText = preciseTruncate(fittedText)
+        }
+        return fittedText
+    }
+
+    protected abstract fun roughTruncate(text: String, residualLength: Int): String
+    protected abstract fun preciseTruncate(text: String): String
+    protected abstract fun attachWith(text: String, with: String): String
+}
+
+class TruncateStart : BaseTruncate() {
+    override fun roughTruncate(text: String, residualLength: Int): String {
+        if (text.length <= residualLength) return text
+
+        hasBeenTruncated = true
+        return text.substring(residualLength, text.length)
+    }
+
+    override fun preciseTruncate(text: String): String = text.substring(1, text.length)
+
+    override fun attachWith(text: String, with: String): String = with + text
+}
+
+class TruncateMiddle : BaseTruncate() {
+
+    override fun roughTruncate(text: String, residualLength: Int): String {
+        if (text.length <= residualLength) return text
+
+        hasBeenTruncated = true
+        val halfOfResidualLength = residualLength / 2
+        val leftSide = text.substring(0, halfOfResidualLength)
+        val rightSide = text.substring(text.length - halfOfResidualLength, text.length)
+
+        return leftSide + rightSide
+    }
+
+    override fun preciseTruncate(text: String): String {
+        val middlePosition = text.length / 2
+        return if (text.length.isEven()) {
+            val leftSide = text.substring(0, middlePosition - 1)
+            val rightSide = text.substring(middlePosition, text.length)
+            leftSide + rightSide
+        } else {
+            val leftSide = text.substring(0, middlePosition)
+            val rightSide = text.substring(middlePosition + 1, text.length)
+            leftSide + rightSide
+        }
+    }
+
+    override fun attachWith(text: String, with: String): String {
+        val cuttingPosition = text.length / 2
+        val leftSide = text.substring(0, cuttingPosition)
+        val rightSide = text.substring(cuttingPosition, text.length)
+        return leftSide + with + rightSide
+    }
+}
+
+class TruncateEnd : BaseTruncate() {
+    override fun roughTruncate(text: String, residualLength: Int): String {
+        if (text.length <= residualLength) return text
+
+        hasBeenTruncated = true
+        return text.substring(0, residualLength)
+    }
+
+    override fun preciseTruncate(text: String): String = text.substring(0, text.length - 1)
+
+    override fun attachWith(text: String, with: String): String = text + with
+}
+
+fun TextView.truncateWith(text: String, type: TruncateType, with: String = "..."): String {
+    val truncate = Truncate.create(type)
+    return truncate.apply(this, text, with)
+}
+
+fun TextView.truncateStartWith(text: String, with: String = "..."): String =
+        this.truncateWith(text, TruncateType.START, with)
+
+fun TextView.truncateMiddleWith(text: String, with: String = "..."): String =
+        this.truncateWith(text, TruncateType.MIDDLE, with)
+
+fun TextView.truncateEndWith(text: String, with: String = "..."): String =
+        this.truncateWith(text, TruncateType.END, with)