Magnifier for iOS 17+ (#1000)

## Proposed Changes - Text field and selection container magnifier for iOS 17+ <img src="https://github.com/JetBrains/compose-multiplatform-core/assets/63979218/f7fd9432-066f-4cc3-ad96-5029bfe75848" height = 300> ## Testing Test: try magnifier in all types of text fields ## Issues Fixed Partly: JetBrains/compose-multiplatform#3692
JetBrains · Apr 5, 2024 · 5a698ba · 5a698ba
1 parent ae0fd0d
commit 5a698ba
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Showing 8 changed files with 722 additions and 14 deletions.
diff --git a/...ation/src/commonMain/kotlin/androidx/compose/foundation/text/LongPressTextDragObserver.kt b/...ation/src/commonMain/kotlin/androidx/compose/foundation/text/LongPressTextDragObserver.kt
@@ -23,6 +23,7 @@ import androidx.compose.foundation.gestures.detectDragGesturesAfterLongPress
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.input.pointer.PointerInputScope
 import androidx.compose.ui.util.fastAny
+import kotlin.coroutines.cancellation.CancellationException
 import kotlinx.coroutines.CoroutineStart
 import kotlinx.coroutines.coroutineScope
 import kotlinx.coroutines.launch
@@ -84,6 +85,12 @@ internal suspend fun PointerInputScope.detectDownAndDragGesturesWithObserver(
         }
         launch(start = CoroutineStart.UNDISPATCHED) {
             detectDragGesturesWithObserver(observer)
+        }.invokeOnCompletion {
+            // Otherwise observer won't be notified if
+            // composable was disposed before the drag cancellation
+            if (it is CancellationException){
+                observer.onCancel()
+            }
         }
     }
 }

diff --git a/...commonMain/kotlin/androidx/compose/foundation/text/selection/TextFieldSelectionManager.kt b/...commonMain/kotlin/androidx/compose/foundation/text/selection/TextFieldSelectionManager.kt
@@ -152,13 +152,13 @@ internal class TextFieldSelectionManager(
      * when the dragging is stopped.
      */
     var draggingHandle: Handle? by mutableStateOf(null)
-        private set
+        internal set
 
     /**
      * The current position of a drag, in decoration box coordinates.
      */
     var currentDragPosition: Offset? by mutableStateOf(null)
-        private set
+        internal set
 
     /**
      * The previous offset of a drag, before selection adjustments.
@@ -450,7 +450,10 @@ internal class TextFieldSelectionManager(
                 updateFloatingToolbar(show = true)
             }
 
-            override fun onCancel() {}
+            override fun onCancel() {
+                draggingHandle = null
+                currentDragPosition = null
+            }
         }
 
     /**

diff --git a/...ction/TextFieldSelectionManager.native.kt → ...ection/TextFieldSelectionManager.macos.kt b/...ction/TextFieldSelectionManager.native.kt → ...ection/TextFieldSelectionManager.macos.kt
@@ -1,5 +1,5 @@
 /*
- * Copyright 2021 The Android Open Source Project
+ * Copyright 2024 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.

diff --git a/...koMain/kotlin/androidx/compose/foundation/text/CupertinoTextFieldPointerModifier.skiko.kt b/...koMain/kotlin/androidx/compose/foundation/text/CupertinoTextFieldPointerModifier.skiko.kt
@@ -51,7 +51,7 @@ internal fun Modifier.cupertinoTextFieldPointer(
 ): Modifier = if (enabled) {
     // TODO switch to ".updateSelectionTouchMode { state.isInTouchMode = it }" as in defaultTextFieldPointer
     if (isInTouchMode) {
-        val longPressHandlerModifier = getLongPressHandlerModifier(state, offsetMapping)
+        val longPressHandlerModifier = getLongPressHandlerModifier(state, offsetMapping, manager)
         val tapHandlerModifier = getTapHandlerModifier(
             interactionSource,
             state,
@@ -110,7 +110,7 @@ private fun getTapHandlerModifier(
                     if (currentState.handleState != HandleState.Selection) {
                         currentState.layoutResult?.let { layoutResult ->
                             // TODO: Research native behavior with any text transformations (which adds symbols like with using NSNumberFormatter)
-                            if (manager.visualTransformation != VisualTransformation.None) {
+                            if (currentManager.visualTransformation != VisualTransformation.None) {
                                 TextFieldDelegate.setCursorOffset(
                                     touchPointOffset,
                                     layoutResult,
@@ -126,7 +126,7 @@ private fun getTapHandlerModifier(
                                     offsetMapping = currentOffsetMapping,
                                     showContextMenu = {
                                         // it shouldn't be selection, but this is a way to call context menu in BasicTextField
-                                        manager.enterSelectionMode(true)
+                                        currentManager.enterSelectionMode(true)
                                     },
                                     onValueChange = currentState.onValueChange
                                 )
@@ -175,10 +175,12 @@ private fun getTapHandlerModifier(
 @Composable
 private fun getLongPressHandlerModifier(
     state: TextFieldState,
-    offsetMapping: OffsetMapping
+    offsetMapping: OffsetMapping,
+    manager: TextFieldSelectionManager,
 ): Modifier {
     val currentState by rememberUpdatedState(state)
     val currentOffsetMapping by rememberUpdatedState(offsetMapping)
+    val currentManager by rememberUpdatedState(manager)
 
     return Modifier.pointerInput(Unit) {
         val longTapActionsObserver =
@@ -187,6 +189,9 @@ private fun getLongPressHandlerModifier(
                 var dragBeginOffset = Offset.Zero
 
                 override fun onStart(startPoint: Offset) {
+                    currentManager.draggingHandle = Handle.SelectionEnd
+                    currentManager.currentDragPosition = startPoint
+
                     currentState.layoutResult?.let { layoutResult ->
                         TextFieldDelegate.setCursorOffset(
                             startPoint,
@@ -204,6 +209,7 @@ private fun getLongPressHandlerModifier(
                     dragTotalDistance += delta
                     currentState.layoutResult?.let { layoutResult ->
                         val currentDragPosition = dragBeginOffset + dragTotalDistance
+                        currentManager.currentDragPosition = currentDragPosition
                         TextFieldDelegate.setCursorOffset(
                             currentDragPosition,
                             layoutResult,
@@ -219,9 +225,15 @@ private fun getLongPressHandlerModifier(
 
                 override fun onUp() {}
 
-                override fun onStop() {}
+                override fun onStop() {
+                    currentManager.draggingHandle = null
+                    currentManager.currentDragPosition = null
+                }
 
-                override fun onCancel() {}
+                override fun onCancel() {
+                    currentManager.draggingHandle = null
+                    currentManager.currentDragPosition = null
+                }
             }
 
         detectDragGesturesAfterLongPress(
@@ -339,4 +351,4 @@ private fun createTextFieldValue(
         annotatedString = annotatedString,
         selection = selection
     )
-}
+}