Fix SelectableLazyList scrolling logic and event handling (#179)

JetBrains · Oct 16, 2023 · 4da6105 · 4da6105
1 parent a36e52d
commit 4da6105
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Showing 2 changed files with 16 additions and 5 deletions.
diff --git a/core/src/main/kotlin/org/jetbrains/jewel/foundation/lazy/SelectableLazyColumn.kt b/core/src/main/kotlin/org/jetbrains/jewel/foundation/lazy/SelectableLazyColumn.kt
@@ -12,6 +12,7 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -22,6 +23,7 @@ import androidx.compose.ui.input.key.onPreviewKeyEvent
 import androidx.compose.ui.input.pointer.PointerEventType
 import androidx.compose.ui.input.pointer.pointerInput
 import androidx.compose.ui.unit.dp
+import kotlinx.coroutines.launch
 import org.jetbrains.jewel.foundation.lazy.SelectableLazyListScopeContainer.Entry
 import org.jetbrains.jewel.foundation.tree.DefaultSelectableLazyColumnEventAction
 import org.jetbrains.jewel.foundation.tree.DefaultSelectableLazyColumnKeyActions
@@ -48,6 +50,7 @@ fun SelectableLazyColumn(
     interactionSource: MutableInteractionSource = remember { MutableInteractionSource() },
     content: SelectableLazyListScope.() -> Unit,
 ) {
+    val scope = rememberCoroutineScope()
     val container = SelectableLazyListScopeContainer()
         .apply(content)
 
@@ -74,7 +77,16 @@ fun SelectableLazyColumn(
             .focusable(interactionSource = interactionSource)
             .onPreviewKeyEvent { event ->
                 if (state.lastActiveItemIndex != null) {
-                    keyActions.handleOnKeyEvent(event, keys, state, selectionMode).invoke(event)
+                    val actionHandled = keyActions
+                        .handleOnKeyEvent(event, keys, state, selectionMode)
+                        .invoke(event)
+                    if (actionHandled) {
+                        scope.launch {
+                            state.lastActiveItemIndex?.let {
+                                state.scrollToItem(it)
+                            }
+                        }
+                    }
                 }
                 true
             },

diff --git a/core/src/main/kotlin/org/jetbrains/jewel/foundation/lazy/SelectableLazyListState.kt b/core/src/main/kotlin/org/jetbrains/jewel/foundation/lazy/SelectableLazyListState.kt
@@ -19,6 +19,7 @@ val SelectableLazyListState.visibleItemsRange
     get() = firstVisibleItemIndex..firstVisibleItemIndex + layoutInfo.visibleItemsInfo.size
 
 interface SelectableScope {
+
     var selectedKeys: List<Any>
 }
 
@@ -41,16 +42,14 @@ class SelectableLazyListState(
      * @param itemIndex The index of the item to focus on.
      * @param animateScroll Whether to animate the scroll to the focused item.
      * @param scrollOffset The scroll offset for the focused item.
-     * @param skipScroll Whether to skip the scroll to the focused item.
      */
     suspend fun scrollToItem(
         itemIndex: Int,
         animateScroll: Boolean = false,
         scrollOffset: Int = 0,
-        skipScroll: Boolean = false,
     ) {
         val visibleRange = visibleItemsRange.drop(2).dropLast(4)
-        if (!skipScroll && itemIndex !in visibleRange && visibleRange.isNotEmpty()) {
+        if (itemIndex !in visibleRange && visibleRange.isNotEmpty()) {
             when {
                 itemIndex < visibleRange.first() -> lazyListState.scrollToItem(
                     max(0, itemIndex - 2),
@@ -59,7 +58,7 @@ class SelectableLazyListState(
                 )
 
                 itemIndex > visibleRange.last() -> {
-                    lazyListState.scrollToItem(max(itemIndex - (visibleRange.size + 1), 0), animateScroll, 0)
+                    lazyListState.scrollToItem(max(itemIndex - (visibleRange.size + 2), 0), animateScroll, 0)
                 }
             }
         }