refactor: isolate dictionary rows from mutation-block recomposition

Delete-block flag becomes a () -> Boolean provider read at state/gesture time, so flipping it no longer recomposes the whole Dictionaries block.
2026-09-04 01:53:06 +08:00
parent 4f202f8c10
commit 628813c3f6
2 changed files with 33 additions and 17 deletions
@@ -28,6 +28,7 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.rememberUpdatedState
 import androidx.compose.runtime.setValue
+import androidx.compose.runtime.snapshotFlow
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clipToBounds
@@ -83,7 +84,7 @@ fun DictionaryListItem(
    onToggle: () -> Unit,
    onDelete: () -> Unit,
    modifier: Modifier = Modifier,
-    canDelete: Boolean = true
+    isDeleteBlocked: () -> Boolean = { false }
 ) {
    val haptic = LocalHapticFeedback.current
    val density = LocalDensity.current
@@ -95,8 +96,9 @@ fun DictionaryListItem(
    val offsetAnim = remember { Animatable(0f) }

    var rawOffset by remember { mutableFloatStateOf(0f) }
-    val isDeleteRevealed by remember(canDelete) {
-        derivedStateOf { canDelete && rawOffset <= -swipeThresholdPx }
+    val isDeleteBlockedCurrent by rememberUpdatedState(isDeleteBlocked)
+    val isDeleteRevealed by remember {
+        derivedStateOf { !isDeleteBlockedCurrent() && rawOffset <= -swipeThresholdPx }
    }

    LaunchedEffect(isDeleteRevealed) {
@@ -105,10 +107,13 @@ fun DictionaryListItem(
        }
    }

-    LaunchedEffect(canDelete) {
-        if (!canDelete) {
+    LaunchedEffect(Unit) {
+        snapshotFlow { isDeleteBlockedCurrent() }
+            .collect { blocked ->
+                if (blocked) {
                    rawOffset = 0f
-            offsetAnim.snapTo(0f)
+                    scope.launch { offsetAnim.snapTo(0f) }
+                }
            }
    }

@@ -142,13 +147,14 @@ fun DictionaryListItem(
                .height(DictionaryItemHeight)
                .background(MaterialTheme.colorScheme.surfaceVariant)
                .graphicsLayer { translationX = offsetAnim.value }
-                .pointerInput(canDelete, maxSwipePx, swipeThresholdPx) {
-                    if (!canDelete) return@pointerInput
+                .pointerInput(maxSwipePx, swipeThresholdPx) {
                    detectHorizontalDragGestures(
                        onDragStart = {
+                            if (isDeleteBlockedCurrent()) return@detectHorizontalDragGestures
                            haptic.performHapticFeedback(HapticFeedbackType.TextHandleMove)
                        },
                        onDragEnd = {
+                            if (isDeleteBlockedCurrent()) return@detectHorizontalDragGestures
                            val target = if (rawOffset <= -swipeThresholdPx) -maxSwipePx else 0f
                            rawOffset = target
                            scope.launch {
@@ -159,6 +165,7 @@ fun DictionaryListItem(
                            }
                        },
                        onDragCancel = {
+                            if (isDeleteBlockedCurrent()) return@detectHorizontalDragGestures
                            val target = if (rawOffset <= -swipeThresholdPx) -maxSwipePx else 0f
                            rawOffset = target
                            scope.launch {
@@ -169,6 +176,7 @@ fun DictionaryListItem(
                            }
                        },
                        onHorizontalDrag = { _, dragAmount ->
+                            if (isDeleteBlockedCurrent()) return@detectHorizontalDragGestures
                            val newOffset = (rawOffset + dragAmount).coerceIn(-maxSwipePx, 0f)
                            rawOffset = newOffset
                            scope.launch { offsetAnim.snapTo(newOffset) }
@@ -13,6 +13,7 @@ import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberUpdatedState
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.hapticfeedback.HapticFeedbackType
@@ -75,6 +76,13 @@ fun DictionaryManagement(
        derivedStateOf { importState is ImportState.Importing || importState is ImportState.Extracting }
    }
    val hasEnabledSources by remember(sources) { derivedStateOf { sources.any { it.isEnabled } } }
+    val isBlockingMutations = isInProgress
+
+    // Invariant: the mutation-block flag is read only at state-read/gesture time (derivedStateOf,
+    // snapshotFlow, pointerInput callbacks), never at row composition time. A composition-time read
+    // (e.g. Modifier.alpha(if (isDeleteBlocked()) ...)) would invalidate every row on each flip.
+    val isMutationsBlockedState = rememberUpdatedState(isBlockingMutations)
+    val isDeleteBlocked = remember { { isMutationsBlockedState.value } }

    SectionCard(
        modifier = modifier
@@ -125,13 +133,13 @@ fun DictionaryManagement(

                    // Disable accessibility on background content during import to improve performance.
                    // The progress dialog remains accessible for cancellation.
-                    val backgroundModifier = if (isInProgress) {
+                    val backgroundModifier = if (isBlockingMutations) {
                        Modifier.semantics(mergeDescendants = true) { }
                    } else {
                        Modifier
                    }

-                    if (dictionaries.isEmpty() && !isInProgress) {
+                    if (dictionaries.isEmpty() && !isBlockingMutations) {
                        Column(
                            modifier = backgroundModifier
                                .fillMaxWidth()
@@ -153,7 +161,7 @@ fun DictionaryManagement(
                            )
                        }
                    } else {
-                        if (dictionaryStatus is DictionaryStatus.NeedsUpdate && !isInProgress && hasEnabledSources) {
+                        if (dictionaryStatus is DictionaryStatus.NeedsUpdate && !isBlockingMutations && hasEnabledSources) {
                            DictionaryUpdateCard(
                                onStartDownload = onStartDownload,
                                modifier = backgroundModifier
@@ -167,10 +175,10 @@ fun DictionaryManagement(
                            modifier = Modifier
                                .fillMaxWidth()
                                .then(backgroundModifier),
-                            canDelete = !isInProgress
+                            isDeleteBlocked = isDeleteBlocked
                        )

-                        if (!isInProgress) {
+                        if (!isBlockingMutations) {
                            DictionaryActionButtons(
                                onAddSource = {
                                    haptic.performHapticFeedback(HapticFeedbackType.TextHandleMove)
@@ -248,7 +256,7 @@ private fun DictionaryListSection(
    onToggleDictionary: (String) -> Unit,
    onDeleteDictionary: (Dictionary) -> Unit,
    modifier: Modifier = Modifier,
-    canDelete: Boolean = true
+    isDeleteBlocked: () -> Boolean = { false }
 ) {
    Column(
        modifier = modifier,
@@ -259,7 +267,7 @@ private fun DictionaryListSection(
                dictionary = dictionary,
                onToggle = { onToggleDictionary(dictionary.path) },
                onDelete = { onDeleteDictionary(dictionary) },
-                canDelete = canDelete
+                isDeleteBlocked = isDeleteBlocked
            )
        }
    }