Fix missing clicks inside SelectionContainer (#1106)

## Proposed Changes

- Do not recreate modifier nodes on focus change - Buttons inside
`DisableSelection` now clickable. Before it receives only second click
- Do not consume UP events if there were no drag before - Buttons inside
`SelectionContainer` now clickable, but text inside them is still
selectable
- `SelectionManager.hasFocus` now `true` if any of it's children is
focusable
- `onClearSelectionRequested` now triggers on consumed click on
focusable, non-selectable child

## Testing

Test: `Selection` page in mpp

## Issues Fixed

Fixes JetBrains/compose-multiplatform#1450

compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/text/selection/SelectionContainer.kt

@@ -150,7 +150,7 @@ internal fun SelectionContainer(
     DisposableEffect(manager) {
         onDispose {
             manager.onRelease()
-            manager.hasFocus = false
+            manager.focusState = null
         }
     }
 }

compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/text/selection/SelectionGestures.kt

@@ -183,13 +183,15 @@ private suspend fun AwaitPointerEventScope.mouseSelection(
 
         val started = observer.onStart(downChange.position, selectionAdjustment)
         if (started) {
+            var dragConsumed = selectionAdjustment != SelectionAdjustment.None
             val shouldConsumeUp = drag(downChange.id) {
                 if (observer.onDrag(it.position, selectionAdjustment)) {
                     it.consume()
+                    dragConsumed = true
                 }
             }
 
-            if (shouldConsumeUp) {
+            if (shouldConsumeUp && dragConsumed) {
                 currentEvent.changes.fastForEach {
                     if (it.changedToUp()) it.consume()
                 }

compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/text/selection/SelectionManager.kt

@@ -18,8 +18,6 @@ package androidx.compose.foundation.text.selection
 
 import androidx.annotation.VisibleForTesting
 import androidx.compose.foundation.focusable
-import androidx.compose.foundation.gestures.awaitEachGesture
-import androidx.compose.foundation.gestures.waitForUpOrCancellation
 import androidx.compose.foundation.text.Handle
 import androidx.compose.foundation.text.TextDragObserver
 import androidx.compose.foundation.text.selection.Selection.AnchorInfo
@@ -31,6 +29,7 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.focus.FocusRequester
+import androidx.compose.ui.focus.FocusState
 import androidx.compose.ui.focus.focusRequester
 import androidx.compose.ui.focus.onFocusChanged
 import androidx.compose.ui.geometry.Offset
@@ -41,7 +40,12 @@ import androidx.compose.ui.hapticfeedback.HapticFeedback
 import androidx.compose.ui.hapticfeedback.HapticFeedbackType
 import androidx.compose.ui.input.key.KeyEvent
 import androidx.compose.ui.input.key.onKeyEvent
-import androidx.compose.ui.input.pointer.PointerInputScope
+import androidx.compose.ui.input.pointer.AwaitPointerEventScope
+import androidx.compose.ui.input.pointer.PointerEvent
+import androidx.compose.ui.input.pointer.PointerEventPass
+import androidx.compose.ui.input.pointer.PointerInputChange
+import androidx.compose.ui.input.pointer.changedToUp
+import androidx.compose.ui.input.pointer.changedToUpIgnoreConsumed
 import androidx.compose.ui.input.pointer.pointerInput
 import androidx.compose.ui.layout.LayoutCoordinates
 import androidx.compose.ui.layout.boundsInWindow
@@ -54,6 +58,7 @@ import androidx.compose.ui.platform.TextToolbarStatus
 import androidx.compose.ui.text.AnnotatedString
 import androidx.compose.ui.text.buildAnnotatedString
 import androidx.compose.ui.unit.IntSize
+import androidx.compose.ui.util.fastAll
 import androidx.compose.ui.util.fastAny
 import androidx.compose.ui.util.fastFold
 import androidx.compose.ui.util.fastForEach
@@ -120,10 +125,25 @@ internal class SelectionManager(private val selectionRegistrar: SelectionRegistr
      */
     var focusRequester: FocusRequester = FocusRequester()
 
+    /**
+     * Current focus state.
+     */
+    var focusState: FocusState? by mutableStateOf(null)
+
+    /**
+     * Return true if the corresponding SelectionContainer has a child that is focused.
+     */
+    val hasFocus get() = focusState?.hasFocus ?: false
+
     /**
      * Return true if the corresponding SelectionContainer is focused.
      */
-    var hasFocus: Boolean by mutableStateOf(false)
+    private val isContainerFocused get() = focusState?.isFocused ?: false
+
+    /**
+     * Return true if dragging gesture is currently in process.
+     */
+    private val isDraggingInProgress get() = draggingHandle != null
 
     /**
      * Modifier for selection container.
@@ -134,10 +154,10 @@ internal class SelectionManager(private val selectionRegistrar: SelectionRegistr
             .onGloballyPositioned { containerLayoutCoordinates = it }
             .focusRequester(focusRequester)
             .onFocusChanged { focusState ->
-                if (!focusState.isFocused && hasFocus) {
+                if (!focusState.hasFocus && hasFocus) {
                     onRelease()
                 }
-                hasFocus = focusState.isFocused
+                this.focusState = focusState
             }
             .focusable()
             .updateSelectionTouchMode { isInTouchMode = it }
@@ -236,7 +256,7 @@ internal class SelectionManager(private val selectionRegistrar: SelectionRegistr
         private set
 
     private val shouldShowMagnifier
-        get() = draggingHandle != null && isInTouchMode && !isTriviallyCollapsedSelection()
+        get() = isDraggingInProgress && isInTouchMode && !isTriviallyCollapsedSelection()
 
     @VisibleForTesting
     internal var previousSelectionLayout: SelectionLayout? = null
@@ -664,20 +684,27 @@ internal class SelectionManager(private val selectionRegistrar: SelectionRegistr
         override fun onCancel() = done()
     }
 
-    /**
-     * Detect tap without consuming the up event.
-     */
-    private suspend fun PointerInputScope.detectNonConsumingTap(onTap: (Offset) -> Unit) {
-        awaitEachGesture {
-            waitForUpOrCancellation()?.let {
-                onTap(it.position)
+    private fun Modifier.onClearSelectionRequested(block: () -> Unit): Modifier =
+        pointerInput(Unit) {
+            awaitPointerEventScope {
+                while (true) {
+                    awaitPointerEventWhereAllChanges(PointerEventPass.Initial) {
+                        it.changedToUpIgnoreConsumed()
+                    }?.let {
+                        if (!isContainerFocused && !isDraggingInProgress) {
+                            block()
+                        }
+                    }
+                    awaitPointerEventWhereAllChanges(PointerEventPass.Main) {
+                        it.changedToUp()
+                    }?.let {
+                        if (isContainerFocused) {
+                            block()
+                        }
+                    }
+                }
             }
         }
-    }
-
-    private fun Modifier.onClearSelectionRequested(block: () -> Unit): Modifier {
-        return if (hasFocus) pointerInput(Unit) { detectNonConsumingTap { block() } } else this
-    }
 
     private fun convertToContainerCoordinates(
         layoutCoordinates: LayoutCoordinates,
@@ -992,3 +1019,12 @@ internal fun LayoutCoordinates.visibleBounds(): Rect {
 
 internal fun Rect.containsInclusive(offset: Offset): Boolean =
     offset.x in left..right && offset.y in top..bottom
+
+/**
+ * Suspend until a [PointerEvent] is reported to the specified input [pass].
+ * Returns it if all changes match the given [predicate].
+ */
+private suspend fun AwaitPointerEventScope.awaitPointerEventWhereAllChanges(
+    pass: PointerEventPass = PointerEventPass.Main,
+    predicate: (PointerInputChange) -> Boolean,
+) = awaitPointerEvent(pass).takeIf { it.changes.fastAll(predicate) }

compose/mpp/demo/src/commonMain/kotlin/androidx/compose/mpp/demo/components/Selection.kt

@@ -17,27 +17,50 @@
 package androidx.compose.mpp.demo.components
 
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.text.selection.DisableSelection
 import androidx.compose.foundation.text.selection.SelectionContainer
+import androidx.compose.material3.Button
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.dp
 
 @Composable
 fun SelectionExample() {
-    SelectionContainer(
-        Modifier.padding(24.dp).fillMaxWidth()
-    ) {
-        Column {
-            Text(
-                "I'm a selection container. Double tap on word to select a word." +
-                    " Triple tap on content to select whole paragraph.\nAnother paragraph for testing.\n" +
-                    "And another one."
-            )
-            Text("I'm another Text() block. Let's try to select me!")
-            Text("I'm yet another Text() with multiparagraph structure block.\nLet's try to select me!")
+    var count by remember { mutableStateOf(0) }
+    Column {
+        Button(onClick = { count++ }) {
+            Text("Outside Count: $count")
+        }
+        SelectionContainer(
+            Modifier.padding(24.dp).fillMaxWidth()
+        ) {
+            Column {
+                Text(
+                    "I'm a selection container. Double tap on word to select a word." +
+                        " Triple tap on content to select whole paragraph.\nAnother paragraph for testing.\n" +
+                        "And another one."
+                )
+                Row {
+                    DisableSelection {
+                        Button(onClick = { count++ }) {
+                            Text("DisableSelection Count: $count")
+                        }
+                    }
+                    Button(onClick = { count++ }) {
+                        Text("SelectionContainer Count: $count")
+                    }
+                }
+                Text("I'm another Text() block. Let's try to select me!")
+                Text("I'm yet another Text() with multiparagraph structure block.\nLet's try to select me!")
+            }
         }
     }
 }