Adopt PlatformTextInputService2 (#2990)

Extend the functionality of the `TextEditingScope` and adjust its
behaviour to align with the `EditProcessor`'s commands.
Apply `recomposeAndLayout` after edit commands to recalculate the text
and layout state.
Refactor the `UIKitTextInputService` to use the
`PlatformTextInputMethodRequest` directly to bypass issues caused by
delays in mutable state propagation.
Add the `UIKitTextInputServiceAdapter` to support the deprecated
`PlatformTextInputService`.

Fixes
https://youtrack.jetbrains.com/issue/CMP-7832/iOS-Adopt-PlatformTextInputService2
Fixes
https://youtrack.jetbrains.com/issue/CMP-7983/BasicTextFieldTextFieldState-inputTransformation-reports-inconsistent-changes-between-Android-and-iOS
Fixes
https://youtrack.jetbrains.com/issue/CMP-9566/BasicTextField-w-InputTransformation-incorrect-internal-state-on-iOS

## Release Notes
### Fixes - iOS
- Fix issue where `BasicTextField` reported inconsistent changes between
Android and iOS
- Fix issue where a `BasicTextField` with `InputTransformation` may use
the incorrect internal text state.

Author: ASalavei

compose/foundation/foundation/src/skikoMain/kotlin/androidx/compose/foundation/text/input/internal/LegacyPlatformTextInputServiceAdapter.skiko.kt

@@ -32,7 +32,9 @@ import androidx.compose.ui.text.input.FinishComposingTextCommand
 import androidx.compose.ui.text.input.ImeAction
 import androidx.compose.ui.text.input.ImeOptions
 import androidx.compose.ui.text.input.OffsetMapping
+import androidx.compose.ui.text.input.SetComposingRegionCommand
 import androidx.compose.ui.text.input.SetComposingTextCommand
+import androidx.compose.ui.text.input.SetSelectionCommand
 import androidx.compose.ui.text.input.TextEditingScope
 import androidx.compose.ui.text.input.TextEditorState
 import androidx.compose.ui.text.input.TextFieldValue
@@ -114,6 +116,7 @@ internal actual fun createLegacyPlatformTextInputServiceAdapter():
                 override fun get(index: Int): Char = textFieldValue.text[index]
                 override fun subSequence(startIndex: Int, endIndex: Int): CharSequence =
                     textFieldValue.text.subSequence(startIndex, endIndex)
+                override val text: String get() = textFieldValue.text
             }
 
             val editBlock: (block: TextEditingScope.() -> Unit) -> Unit = { block ->
@@ -152,6 +155,12 @@ private fun TextEditingScope(commands: MutableList<EditCommand>) = object : Text
         )
     }
 
+    override fun setSelection(start: Int, end: Int) {
+        commands.add(
+            SetSelectionCommand(start, end)
+        )
+    }
+
     override fun commitText(
         text: CharSequence,
         newCursorPosition: Int
@@ -161,6 +170,12 @@ private fun TextEditingScope(commands: MutableList<EditCommand>) = object : Text
         )
     }
 
+    override fun setComposingRegion(start: Int, end: Int) {
+        commands.add(
+            SetComposingRegionCommand(start, end)
+        )
+    }
+
     override fun setComposingText(
         text: CharSequence,
         newCursorPosition: Int

compose/foundation/foundation/src/skikoMain/kotlin/androidx/compose/foundation/text/input/internal/TextInputSession.skiko.kt

@@ -143,18 +143,11 @@ private inline fun (() -> TextFieldCharSequence).asTextEditorState() = object :
     override val composition: TextRange?
         get() = this@asTextEditorState().composition
 
-    override fun toString(): String = this@asTextEditorState().toString()
-
+    override val text: String get() = this@asTextEditorState().toString()
 }
 
 @OptIn(ExperimentalComposeUiApi::class)
 private fun TextEditingScope(buffer: TextFieldBuffer) = object : TextEditingScope {
-    private var TextFieldBuffer.cursor: Int
-        get() = if (selection.collapsed) selection.end else -1
-        set(value) {
-            setSelectionCoerced(value, value)
-        }
-
     // Be careful about using TextRange.start/end, as the selection can be reversed (start > end).
     // Prefer to use TextRange.min/max.
 
@@ -180,15 +173,17 @@ private fun TextEditingScope(buffer: TextFieldBuffer) = object : TextEditingScop
         )
     }
 
+    override fun setSelection(start: Int, end: Int) {
+        buffer.setSelectionCoerced(start, end)
+    }
+
     override fun commitText(text: CharSequence, newCursorPosition: Int) {
         // API description says replace ongoing composition text if there. Then, if there is no
         // composition text, insert text into the cursor position or replace selection.
         val replacementRange = buffer.composition ?: buffer.selection
         buffer.replace(replacementRange.min, replacementRange.max, text)
 
-        // After replace function is called, the editing buffer places the cursor at the end of the
-        // modified range.
-        val newCursor = buffer.cursor
+        val newCursor = replacementRange.min + text.length
 
         // See API description for the meaning of newCursorPosition.
         val newCursorInBuffer =
@@ -200,19 +195,21 @@ private fun TextEditingScope(buffer: TextFieldBuffer) = object : TextEditingScop
         buffer.setSelectionCoerced(newCursorInBuffer, newCursorInBuffer)
     }
 
+    override fun setComposingRegion(start: Int, end: Int) {
+        buffer.setComposition(start, end)
+    }
+
     override fun setComposingText(text: CharSequence, newCursorPosition: Int) {
         val replacementRange = buffer.composition ?: buffer.selection
         // API doc says, if there is ongoing composing text, replace it with new text.
         // If there is no composing text, insert composing text into the cursor position with
         // removing selected text if any.
         buffer.replace(replacementRange.min, replacementRange.max, text)
         if (text.isNotEmpty()) {
-            buffer.setComposition(replacementRange.min, replacementRange.max + text.length)
+            buffer.setComposition(replacementRange.min, replacementRange.min + text.length)
         }
 
-        // After replace function is called, the editing buffer places the cursor at the end of the
-        // modified range.
-        val newCursor = buffer.cursor
+        val newCursor = replacementRange.min + text.length
 
         // See API description for the meaning of newCursorPosition.
         val newCursorInBuffer =
@@ -222,7 +219,7 @@ private fun TextEditingScope(buffer: TextFieldBuffer) = object : TextEditingScop
                 newCursor + newCursorPosition - text.length
             }
 
-        buffer.cursor = newCursorInBuffer
+        buffer.setSelectionCoerced(newCursorInBuffer, newCursorInBuffer)
     }
 
     override fun finishComposingText() {