Merge pull request #659 from usuiat/fix_nestedscroll_issue_in_timetab…

…le_grid Fix NestedScroll Issue in Timetable Grid to Allow Tab Shrinking on Scroll
DroidKaigi · Aug 19, 2023 · 0ea0e39 · 0ea0e39
2 parents 4f4e26c + 5629cb6
commit 0ea0e39
Show file tree

Hide file tree

Showing 2 changed files with 30 additions and 2 deletions.
diff --git a/...ssions/src/main/java/io/github/droidkaigi/confsched2023/sessions/section/TimetableGrid.kt b/...ssions/src/main/java/io/github/droidkaigi/confsched2023/sessions/section/TimetableGrid.kt
@@ -32,6 +32,8 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.clipToBounds
 import androidx.compose.ui.draw.drawBehind
 import androidx.compose.ui.geometry.Offset
+import androidx.compose.ui.input.nestedscroll.NestedScrollDispatcher
+import androidx.compose.ui.input.nestedscroll.NestedScrollSource
 import androidx.compose.ui.input.pointer.PointerInputChange
 import androidx.compose.ui.input.pointer.PointerInputScope
 import androidx.compose.ui.input.pointer.pointerInput
@@ -69,13 +71,15 @@ data class TimetableGridUiState(val timetable: Timetable)
 @Composable
 fun TimetableGrid(
     uiState: TimetableGridUiState,
+    nestedScrollDispatcher: NestedScrollDispatcher,
     onTimetableItemClick: (TimetableItem) -> Unit,
     modifier: Modifier = Modifier,
 ) {
     val timetableGridState = rememberTimetableGridState()
     TimetableGrid(
         timetable = uiState.timetable,
         timetableState = timetableGridState,
+        nestedScrollDispatcher = nestedScrollDispatcher,
         modifier = modifier,
         contentPadding = PaddingValues(16.dp),
     ) { timetableItem, itemHeightPx ->
@@ -92,6 +96,7 @@ fun TimetableGrid(
 fun TimetableGrid(
     timetable: Timetable,
     timetableState: TimetableState,
+    nestedScrollDispatcher: NestedScrollDispatcher,
     modifier: Modifier = Modifier,
     contentPadding: PaddingValues = PaddingValues(),
     content: @Composable (TimetableItem, Int) -> Unit,
@@ -159,6 +164,7 @@ fun TimetableGrid(
                                 dragAmount,
                                 change.uptimeMillis,
                                 change.position,
+                                nestedScrollDispatcher,
                             )
                         }
                     },
@@ -251,6 +257,7 @@ fun TimetablePreview() {
         modifier = Modifier.fillMaxSize(),
         timetable = Timetable.fake(),
         timetableState = timetableState,
+        nestedScrollDispatcher = remember { NestedScrollDispatcher() },
     ) { timetableItem, itemHeightPx ->
         TimetableGridItem(
             timetableItem = timetableItem,
@@ -572,15 +579,29 @@ private class TimetableScreen(
         dragAmount: Offset,
         timeMillis: Long,
         position: Offset,
+        nestedScrollDispatcher: NestedScrollDispatcher,
     ) {
-        val nextPossibleX = calculatePossibleScrollX(dragAmount.x)
-        val nextPossibleY = calculatePossibleScrollY(dragAmount.y)
+        val parentConsumed = nestedScrollDispatcher.dispatchPreScroll(
+            available = dragAmount,
+            source = NestedScrollSource.Drag,
+        )
+        val nextPossibleX = calculatePossibleScrollX(dragAmount.x - parentConsumed.x)
+        val nextPossibleY = calculatePossibleScrollY(dragAmount.y - parentConsumed.y)
+        val weConsumed = Offset(
+            nextPossibleX - scrollState.scrollX,
+            nextPossibleY - scrollState.scrollY,
+        )
         scrollState.scroll(
             scrollX = nextPossibleX,
             scrollY = nextPossibleY,
             timeMillis = timeMillis,
             position = position,
         )
+        nestedScrollDispatcher.dispatchPostScroll(
+            consumed = parentConsumed + weConsumed,
+            available = dragAmount - weConsumed - parentConsumed,
+            source = NestedScrollSource.Drag,
+        )
     }
 
     fun enableHorizontalScroll(dragX: Float): Boolean {

diff --git a/...sions/src/main/java/io/github/droidkaigi/confsched2023/sessions/section/TimetableSheet.kt b/...sions/src/main/java/io/github/droidkaigi/confsched2023/sessions/section/TimetableSheet.kt
@@ -16,6 +16,7 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.geometry.Offset
 import androidx.compose.ui.input.nestedscroll.NestedScrollConnection
+import androidx.compose.ui.input.nestedscroll.NestedScrollDispatcher
 import androidx.compose.ui.input.nestedscroll.NestedScrollSource
 import androidx.compose.ui.input.nestedscroll.nestedScroll
 import androidx.compose.ui.platform.testTag
@@ -100,11 +101,17 @@ fun TimetableSheet(
                 }
 
                 is GridTimetable -> {
+                    val nestedScrollDispatcher = remember { NestedScrollDispatcher() }
                     TimetableGrid(
                         uiState = requireNotNull(uiState.timetableGridUiState[selectedDay]),
+                        nestedScrollDispatcher = nestedScrollDispatcher,
                         onTimetableItemClick = onTimetableItemClick,
                         modifier = Modifier
                             .fillMaxSize()
+                            .nestedScroll(
+                                timetableSheetContentScrollState.nestedScrollConnection,
+                                nestedScrollDispatcher,
+                            )
                             .weight(1f),
                     )
                 }