Merge branch 'main-upstream' into chess-enhancements-and-bug-fixes

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/compose/TextFieldStateExtensions.kt

@@ -0,0 +1,131 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.commons.compose
+
+import androidx.compose.foundation.text.input.TextFieldState
+import androidx.compose.ui.text.TextRange
+import kotlin.math.max
+import kotlin.math.min
+
+fun TextFieldState.insertUrlAtCursor(url: String) {
+    edit {
+        var toInsert = url.trim()
+        val selStart = selection.start
+        val selEnd = selection.end
+        val text = asCharSequence()
+
+        if (selStart > 0 && text[selStart - 1] != ' ' && text[selStart - 1] != '\n') {
+            toInsert = " $toInsert"
+        }
+
+        // takes the position before adding an empty char after the url
+        val endOfUrlIndex = selStart + toInsert.length
+
+        if (selEnd < length && text[selEnd] != ' ' && text[selEnd] != '\n') {
+            toInsert = "$toInsert "
+        }
+
+        replace(selStart, selEnd, toInsert)
+        selection = TextRange(endOfUrlIndex, endOfUrlIndex)
+    }
+}
+
+fun TextFieldState.replaceCurrentWord(wordToInsert: String) {
+    edit {
+        val text = asCharSequence()
+        val selStart = selection.start
+        val selEnd = selection.end
+        val lastWordStart = currentWordStartIdx(text, selStart)
+        val lastWordEnd = currentWordEndIdx(text, selEnd, length)
+        val cursor = lastWordStart + wordToInsert.length
+        replace(lastWordStart, lastWordEnd, wordToInsert)
+        selection = TextRange(cursor, cursor)
+    }
+}
+
+fun TextFieldState.currentWord(): String {
+    val text = this.text
+    val selection = this.selection
+    if (selection.end != selection.start) return ""
+
+    val start = currentWordStartIdx(text, selection.start)
+    val end = currentWordEndIdx(text, selection.end, text.length)
+
+    return if (start < end) {
+        text.subSequence(start, end).toString()
+    } else {
+        ""
+    }
+}
+
+private fun currentWordStartIdx(
+    text: CharSequence,
+    selectionStart: Int,
+): Int {
+    val previousNewLine = text.lastIndexOf('\n', selectionStart - 1)
+    val previousSpace = text.lastIndexOf(' ', selectionStart - 1)
+
+    return max(
+        previousNewLine,
+        previousSpace,
+    ) + 1
+}
+
+private fun currentWordEndIdx(
+    text: CharSequence,
+    selectionEnd: Int,
+    textLength: Int,
+): Int {
+    val nextNewLine = text.indexOf('\n', selectionEnd)
+    val nextSpace = text.indexOf(' ', selectionEnd)
+
+    if (nextSpace < 0 && nextNewLine < 0) return selectionEnd
+    if (nextSpace > 0 && nextNewLine > 0) {
+        return min(
+            nextNewLine,
+            nextSpace,
+        )
+    }
+    if (nextSpace > 0) {
+        return nextSpace
+    }
+    return nextNewLine
+}
+
+private fun CharSequence.lastIndexOf(
+    char: Char,
+    startIndex: Int,
+): Int {
+    for (i in startIndex downTo 0) {
+        if (this[i] == char) return i
+    }
+    return -1
+}
+
+private fun CharSequence.indexOf(
+    char: Char,
+    startIndex: Int,
+): Int {
+    for (i in startIndex until length) {
+        if (this[i] == char) return i
+    }
+    return -1
+}

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/utils/ListUtils.kt

@@ -22,6 +22,14 @@ package com.vitorpamplona.amethyst.commons.utils
 
 import kotlinx.collections.immutable.ImmutableList
 
+/**
+ * Compares two [ImmutableList] instances by element identity (`===`), not value equality (`==`).
+ *
+ * Returns `true` only when both lists have the same size and each element at the same index
+ * is the exact same object reference.
+ *
+ * Useful for cheap change detection in UI/state pipelines where object identity is meaningful.
+ */
 fun <T> equalImmutableLists(
     list1: ImmutableList<T>,
     list2: ImmutableList<T>,