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Set cacheExtent for SliverFillRemaining widget (#143612)

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When a Sliver with items is outside of the Viewport, but within the Viewport's `cacheExtent`, the framework should create SemanticNodes for the items even though they are out of view. However, for this to work, the Sliver's geometry must have a `cacheExtent` (how much space the sliver took up of the Viewport's `cacheExtent`) greater than 0, otherwise it is [excluded](f01ce9f4cb/packages/flutter/lib/src/rendering/viewport.dart (L311-L315)).

`SliverFillRemaining` widgets that fall outside the viewport did not have this set and therefore were being excluded when SemanticNodes were created, even if they were within the Viewport's `cacheExtent`. This PR sets the `cacheExtent` for `SliverFillRemaining` widgets.

In addition, `RenderSliverFillRemainingWithScrollable` would get dropped from the semantic tree because it's child had a size of 0 when outside the remaining paint extent. To fix, we give the child a `maxExtent` of the sliver's `cacheExtent` if it's outside the remaining paint extent but within the viewport's cacheExtent.

Fixes https://github.com/flutter/flutter/issues/142065.

Definitions:
* `RenderViewport.cacheExtent`:
  ```dart
  /// The viewport has an area before and after the visible area to cache items
  /// that are about to become visible when the user scrolls.
  ///
  /// Items that fall in this cache area are laid out even though they are not
  /// (yet) visible on screen. The [cacheExtent] describes how many pixels
  /// the cache area extends before the leading edge and after the trailing edge
  /// of the viewport.
  ///
  /// The total extent, which the viewport will try to cover with children, is
  /// [cacheExtent] before the leading edge + extent of the main axis +
  /// [cacheExtent] after the trailing edge.
  ///
  /// The cache area is also used to implement implicit accessibility scrolling
  /// on iOS: When the accessibility focus moves from an item in the visible
  /// viewport to an invisible item in the cache area, the framework will bring
  /// that item into view with an (implicit) scroll action.
  ```
* `SliverGeometry.cacheExtent`:
  ```dart
  /// How many pixels the sliver has consumed in the
  /// [SliverConstraints.remainingCacheExtent].
  ```
* `SliverContraints.remainingCacheExtent`:
  ```dart
  /// Describes how much content the sliver should provide starting from the
  /// [cacheOrigin].
  ///
  /// Not all content in the [remainingCacheExtent] will be visible as some
  /// of it might fall into the cache area of the viewport.
  ///
  /// Each sliver should start laying out content at the [cacheOrigin] and
  /// try to provide as much content as the [remainingCacheExtent] allows.
  ```
This commit is contained in:
Victoria Ashworth 2024-03-13 11:34:25 -05:00 committed by GitHub
parent 1ccad1a2a7
commit 825e901e00
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3 changed files with 1329 additions and 1 deletions
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23
packages/flutter/lib/src/rendering/sliver_fill.dart
View file

@ -83,21 +83,36 @@ class RenderSliverFillRemainingWithScrollable extends RenderSliverSingleBoxAdapt
final SliverConstraints constraints = this.constraints;
final double extent = constraints.remainingPaintExtent - math.min(constraints.overlap, 0.0);
final double cacheExtent = calculateCacheOffset(
constraints,
from: 0.0,
to: constraints.viewportMainAxisExtent,
);
if (child != null) {
double maxExtent = extent;
// If sliver has no extent, but is within viewport's cacheExtent, use the
// sliver's cacheExtent as the maxExtent so that it does not get dropped
// from the semantic tree.
if (extent == 0 && cacheExtent > 0) {
maxExtent = cacheExtent;
}
child!.layout(constraints.asBoxConstraints(
minExtent: extent,
maxExtent: extent,
maxExtent: maxExtent,
));
}
final double paintedChildSize = calculatePaintOffset(constraints, from: 0.0, to: extent);
assert(paintedChildSize.isFinite);
assert(paintedChildSize >= 0.0);
geometry = SliverGeometry(
scrollExtent: constraints.viewportMainAxisExtent,
paintExtent: paintedChildSize,
maxPaintExtent: paintedChildSize,
hasVisualOverflow: extent > constraints.remainingPaintExtent || constraints.scrollOffset > 0.0,
cacheExtent: cacheExtent,
);
if (child != null) {
setChildParentData(child!, constraints, geometry!);
@ -162,11 +177,14 @@ class RenderSliverFillRemaining extends RenderSliverSingleBoxAdapter {
final double paintedChildSize = calculatePaintOffset(constraints, from: 0.0, to: extent);
assert(paintedChildSize.isFinite);
assert(paintedChildSize >= 0.0);
final double cacheExtent = calculateCacheOffset(constraints, from: 0.0, to: extent);
geometry = SliverGeometry(
scrollExtent: extent,
paintExtent: paintedChildSize,
maxPaintExtent: paintedChildSize,
hasVisualOverflow: extent > constraints.remainingPaintExtent || constraints.scrollOffset > 0.0,
cacheExtent: cacheExtent,
);
if (child != null) {
setChildParentData(child!, constraints, geometry!);
@ -235,11 +253,14 @@ class RenderSliverFillRemainingAndOverscroll extends RenderSliverSingleBoxAdapte
final double paintedChildSize = calculatePaintOffset(constraints, from: 0.0, to: extent);
assert(paintedChildSize.isFinite);
assert(paintedChildSize >= 0.0);
final double cacheExtent = calculateCacheOffset(constraints, from: 0.0, to: extent);
geometry = SliverGeometry(
scrollExtent: extent,
paintExtent: math.min(maxExtent, constraints.remainingPaintExtent),
maxPaintExtent: maxExtent,
hasVisualOverflow: extent > constraints.remainingPaintExtent || constraints.scrollOffset > 0.0,
cacheExtent: cacheExtent,
);
if (child != null) {
setChildParentData(child!, constraints, geometry!);

921
packages/flutter/test/rendering/sliver_cache_test.dart
View file

@ -872,6 +872,914 @@ void main() {
visible: true,
);
});
group('RenderSliverFillRemaining calculates correct geometry', () {
test('when initially in view', () {
// Viewport is 800x600
const double viewportHeight = 600;
const double viewportWidth = 800;
const double cacheExtent = 250.0;
const double beginningViewportCacheExtent = viewportHeight + cacheExtent;
const double firstSliverHeight = 400;
const double sliverFillRemainingChildHeight = 100.0;
final List<RenderSliver> slivers = <RenderSliver>[
RenderSliverToBoxAdapter(
child: RenderSizedBox(const Size(400.0, firstSliverHeight)),
),
RenderSliverFillRemaining(
child: RenderSizedBox(const Size(100.0, sliverFillRemainingChildHeight)),
)
];
final RenderViewport root = RenderViewport(
crossAxisDirection: AxisDirection.right,
offset: ViewportOffset.zero(),
cacheExtent: cacheExtent,
children: slivers,
);
layout(root);
final RenderSliver firstVisibleSliver = slivers[0];
expectSliverConstraints(
sliver: firstVisibleSliver,
cacheOrigin: 0.0,
remainingPaintExtent: viewportHeight,
remainingCacheExtent: beginningViewportCacheExtent,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: firstVisibleSliver,
paintExtent: firstSliverHeight,
cacheExtent: firstSliverHeight,
visible: true,
);
// With RenderSliverFillRemaining:
// * The child has a minExtent and maxExtent of the remaining space of the
// viewportMainAxisExtent or the height of the child - whichever is larger.
// * The sliver has a paintExtent of the child's minExtent/maxExtent or the
// remainingPaintExtent - whichever is smaller.
// * The sliver has a cacheExtent of the child's minExtent/maxExtent or the
// remainingCacheExtent - whichever is smaller.
final RenderSliverSingleBoxAdapter sliverFillRemaining = slivers[1] as RenderSliverSingleBoxAdapter;
const double extentOfChild = viewportHeight - firstSliverHeight;
double remainingPaintExtent = viewportHeight - firstSliverHeight;
double remainingCacheExtent = beginningViewportCacheExtent - firstSliverHeight;
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: extentOfChild,
minHeight: extentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: extentOfChild,
cacheExtent: extentOfChild,
visible: true,
);
// Overscroll
const double scrollOffset = 50;
root.offset = ViewportOffset.fixed(scrollOffset);
pumpFrame();
remainingPaintExtent = viewportHeight - firstSliverHeight + scrollOffset;
remainingCacheExtent = beginningViewportCacheExtent - firstSliverHeight + scrollOffset;
// With RenderSliverFillRemaining, when you overscroll, the extent of the
// child does not change and therefore neither does paintExtent or cacheExtent.
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: extentOfChild,
minHeight: extentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: extentOfChild,
cacheExtent: extentOfChild,
visible: true,
);
});
test('when scrolled into view', () {
// Viewport is 800x600
const double viewportHeight = 600;
const double viewportWidth = 800;
const double cacheExtent = 250.0;
const double beginningViewportCacheExtent = viewportHeight + cacheExtent;
const double firstSliverHeight = beginningViewportCacheExtent;
const double sliverFillRemainingChildHeight = 100.0;
final List<RenderSliver> slivers = <RenderSliver>[
RenderSliverToBoxAdapter(
child: RenderSizedBox(const Size(400.0, firstSliverHeight)),
),
RenderSliverFillRemaining(
child: RenderSizedBox(const Size(100.0, sliverFillRemainingChildHeight)),
)
];
final RenderViewport root = RenderViewport(
crossAxisDirection: AxisDirection.right,
offset: ViewportOffset.zero(),
cacheExtent: cacheExtent,
children: slivers,
);
layout(root);
final RenderSliver firstVisibleSliver = slivers[0];
expectSliverConstraints(
sliver: firstVisibleSliver,
cacheOrigin: 0.0,
remainingPaintExtent: viewportHeight,
remainingCacheExtent: beginningViewportCacheExtent,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: firstVisibleSliver,
paintExtent: viewportHeight,
cacheExtent: firstSliverHeight,
visible: true,
);
// With RenderSliverFillRemaining:
// * The child has a minExtent and maxExtent of the remaining space of the
// viewportMainAxisExtent or the height of the child - whichever is larger.
// * The sliver has a paintExtent of the child's minExtent/maxExtent or the
// remainingPaintExtent - whichever is smaller.
// * The sliver has a cacheExtent of the child's minExtent/maxExtent or the
// remainingCacheExtent - whichever is smaller.
final RenderSliverSingleBoxAdapter sliverFillRemaining = slivers[1] as RenderSliverSingleBoxAdapter;
const double extentOfChild = sliverFillRemainingChildHeight;
double remainingPaintExtent = 0;
double remainingCacheExtent = 0;
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: extentOfChild,
minHeight: extentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: remainingPaintExtent,
cacheExtent: remainingCacheExtent,
visible: false,
);
// Scroll so RenderSliverFillRemaining is not within viewport, but is
// within remainingCacheExtent.
root.offset = ViewportOffset.fixed(cacheExtent);
pumpFrame();
remainingPaintExtent = 0;
remainingCacheExtent = cacheExtent;
// When within the remainingCacheExtent, the sliver will have a cacheExtent
// of the child's extent.
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: extentOfChild,
minHeight: extentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: remainingPaintExtent,
cacheExtent: extentOfChild,
visible: false,
);
// Scroll so RenderSliverFillRemaining is partially within viewport.
root.offset = ViewportOffset.fixed(cacheExtent + 50);
pumpFrame();
remainingPaintExtent = 50;
remainingCacheExtent = cacheExtent + 50;
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: extentOfChild,
minHeight: extentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: remainingPaintExtent,
cacheExtent: extentOfChild,
visible: true,
);
// Scroll so RenderSliverFillRemaining is completely within viewport.
root.offset = ViewportOffset.fixed(cacheExtent + sliverFillRemainingChildHeight);
pumpFrame();
remainingPaintExtent = sliverFillRemainingChildHeight;
remainingCacheExtent = cacheExtent + sliverFillRemainingChildHeight;
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: extentOfChild,
minHeight: extentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: extentOfChild,
cacheExtent: extentOfChild,
visible: true,
);
// Overscroll
root.offset = ViewportOffset.fixed(cacheExtent + sliverFillRemainingChildHeight + 50);
pumpFrame();
remainingPaintExtent = sliverFillRemainingChildHeight + 50;
remainingCacheExtent = cacheExtent + sliverFillRemainingChildHeight + 50;
// With RenderSliverFillRemaining, when you overscroll, the extent of the
// child does not change and therefore neither does paintExtent or cacheExtent.
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: extentOfChild,
minHeight: extentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: extentOfChild,
cacheExtent: extentOfChild,
visible: true,
);
});
});
group('RenderSliverFillRemainingAndOverscroll calculates correct geometry', () {
test('when initially in view', () {
// Viewport is 800x600
const double viewportHeight = 600;
const double viewportWidth = 800;
const double cacheExtent = 250.0;
const double beginningViewportCacheExtent = viewportHeight + cacheExtent;
const double firstSliverHeight = 400;
const double sliverFillRemainingChildHeight = 100.0;
final List<RenderSliver> slivers = <RenderSliver>[
RenderSliverToBoxAdapter(
child: RenderSizedBox(const Size(400.0, firstSliverHeight)),
),
RenderSliverFillRemainingAndOverscroll(
child: RenderSizedBox(const Size(100.0, sliverFillRemainingChildHeight)),
)
];
final RenderViewport root = RenderViewport(
crossAxisDirection: AxisDirection.right,
offset: ViewportOffset.zero(),
cacheExtent: cacheExtent,
children: slivers,
);
layout(root);
final RenderSliver firstVisibleSliver = slivers[0];
expectSliverConstraints(
sliver: firstVisibleSliver,
cacheOrigin: 0.0,
remainingPaintExtent: viewportHeight,
remainingCacheExtent: beginningViewportCacheExtent,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: firstVisibleSliver,
paintExtent: firstSliverHeight,
cacheExtent: firstSliverHeight,
visible: true,
);
// With RenderSliverFillRemainingAndOverscroll:
// * The child has a minExtent of the remaining space of the viewportMainAxisExtent
// or the height of the child - whichever is larger.
// * The child has a maxExtent of the remaining space of the viewportMainAxisExtent,
// the height of the child, or the remainingPaintExtent - whichever is larger.
// * The sliver has a paintExtent of the child's maxExtent or the
// remainingPaintExtent - whichever is smaller.
// * The sliver has a cacheExtent of the child's minExtent or the
// remainingCacheExtent - whichever is smaller.
final RenderSliverSingleBoxAdapter sliverFillRemaining = slivers[1] as RenderSliverSingleBoxAdapter;
const double minExtentOfChild = viewportHeight - firstSliverHeight;
double maxExtentOfChild = viewportHeight - firstSliverHeight;
double remainingPaintExtent = viewportHeight - firstSliverHeight;
double remainingCacheExtent = beginningViewportCacheExtent - firstSliverHeight;
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: maxExtentOfChild,
minHeight: minExtentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: maxExtentOfChild,
cacheExtent: minExtentOfChild,
visible: true,
);
// Overscroll
const double scrollOffset = 50;
root.offset = ViewportOffset.fixed(scrollOffset);
pumpFrame();
remainingPaintExtent = viewportHeight - firstSliverHeight + scrollOffset;
remainingCacheExtent = beginningViewportCacheExtent - firstSliverHeight + scrollOffset;
// When you overscroll, the child's maxExtent is the
// remainingPaintExtent, since it's the higher value.
maxExtentOfChild = remainingPaintExtent;
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: maxExtentOfChild,
minHeight: minExtentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: maxExtentOfChild,
cacheExtent: minExtentOfChild,
visible: true,
);
});
test('when scrolled into view', () {
// Viewport is 800x600
const double viewportHeight = 600;
const double viewportWidth = 800;
const double cacheExtent = 250.0;
const double beginningViewportCacheExtent = viewportHeight + cacheExtent;
const double firstSliverHeight = beginningViewportCacheExtent;
const double sliverFillRemainingChildHeight = 100.0;
final List<RenderSliver> slivers = <RenderSliver>[
RenderSliverToBoxAdapter(
child: RenderSizedBox(const Size(400.0, firstSliverHeight)),
),
RenderSliverFillRemainingAndOverscroll(
child: RenderSizedBox(const Size(100.0, sliverFillRemainingChildHeight)),
)
];
final RenderViewport root = RenderViewport(
crossAxisDirection: AxisDirection.right,
offset: ViewportOffset.zero(),
cacheExtent: cacheExtent,
children: slivers,
);
layout(root);
final RenderSliver firstVisibleSliver = slivers[0];
expectSliverConstraints(
sliver: firstVisibleSliver,
cacheOrigin: 0.0,
remainingPaintExtent: viewportHeight,
remainingCacheExtent: beginningViewportCacheExtent,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: firstVisibleSliver,
paintExtent: viewportHeight,
cacheExtent: firstSliverHeight,
visible: true,
);
// With RenderSliverFillRemainingAndOverscroll:
// * The child has a minExtent of the remaining space of the viewportMainAxisExtent
// or the height of the child - whichever is larger.
// * The child has a maxExtent of the remaining space of the viewportMainAxisExtent,
// the height of the child, or the remainingPaintExtent - whichever is larger.
// * The sliver has a paintExtent of the child's maxExtent or the
// remainingPaintExtent - whichever is smaller.
// * The sliver has a cacheExtent of the child's minExtent or the
// remainingCacheExtent - whichever is smaller.
final RenderSliverSingleBoxAdapter sliverFillRemaining = slivers[1] as RenderSliverSingleBoxAdapter;
const double minExtentOfChild = sliverFillRemainingChildHeight;
double maxExtentOfChild = sliverFillRemainingChildHeight;
double remainingPaintExtent = 0;
double remainingCacheExtent = 0;
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: maxExtentOfChild,
minHeight: minExtentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: remainingPaintExtent,
cacheExtent: remainingCacheExtent,
visible: false,
);
// Scroll so RenderSliverFillRemainingAndOverscroll is not within viewport,
// but is within remainingCacheExtent.
root.offset = ViewportOffset.fixed(cacheExtent);
pumpFrame();
remainingPaintExtent = 0;
remainingCacheExtent = cacheExtent;
// When within the remainingCacheExtent, the sliver will have a cacheExtent
// of the child's minExtent.
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: maxExtentOfChild,
minHeight: minExtentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: remainingPaintExtent,
cacheExtent: minExtentOfChild,
visible: false,
);
// Scroll so RenderSliverFillRemainingAndOverscroll is partially within
// the viewport.
root.offset = ViewportOffset.fixed(cacheExtent + 50);
pumpFrame();
remainingPaintExtent = 50;
remainingCacheExtent = cacheExtent + 50;
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: maxExtentOfChild,
minHeight: minExtentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: remainingPaintExtent,
cacheExtent: minExtentOfChild,
visible: true,
);
// Scroll so RenderSliverFillRemainingAndOverscroll is completely within
// the viewport.
root.offset = ViewportOffset.fixed(cacheExtent + sliverFillRemainingChildHeight);
pumpFrame();
remainingPaintExtent = sliverFillRemainingChildHeight;
remainingCacheExtent = cacheExtent + sliverFillRemainingChildHeight;
// When completely in view, the slivers's paintExtent is the child's
// maxExtentOfChild, since it's the smaller value.
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: maxExtentOfChild,
minHeight: minExtentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: maxExtentOfChild,
cacheExtent: minExtentOfChild,
visible: true,
);
// Overscroll
root.offset = ViewportOffset.fixed(cacheExtent + sliverFillRemainingChildHeight + 50);
pumpFrame();
remainingPaintExtent = sliverFillRemainingChildHeight + 50;
remainingCacheExtent = cacheExtent + sliverFillRemainingChildHeight + 50;
// When you overscroll, the child's maxExtent is the remainingPaintExtent,
// since it's the higher value.
maxExtentOfChild = remainingPaintExtent;
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: maxExtentOfChild,
minHeight: minExtentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: maxExtentOfChild,
cacheExtent: minExtentOfChild,
visible: true,
);
});
});
group('RenderSliverFillRemainingWithScrollable calculates correct geometry', () {
test('when initially in view', () {
// Viewport is 800x600
const double viewportHeight = 600;
const double viewportWidth = 800;
const double cacheExtent = 250.0;
const double beginningViewportCacheExtent = viewportHeight + cacheExtent;
const double firstSliverHeight = 400;
const double sliverFillRemainingChildHeight = 100.0;
final List<RenderSliver> slivers = <RenderSliver>[
RenderSliverToBoxAdapter(
child: RenderSizedBox(const Size(400.0, firstSliverHeight)),
),
RenderSliverFillRemainingWithScrollable(
child: RenderSizedBox(const Size(100.0, sliverFillRemainingChildHeight)),
)
];
final RenderViewport root = RenderViewport(
crossAxisDirection: AxisDirection.right,
offset: ViewportOffset.zero(),
cacheExtent: cacheExtent,
children: slivers,
);
layout(root);
final RenderSliver firstVisibleSliver = slivers[0];
expectSliverConstraints(
sliver: firstVisibleSliver,
cacheOrigin: 0.0,
remainingPaintExtent: viewportHeight,
remainingCacheExtent: beginningViewportCacheExtent,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: firstVisibleSliver,
paintExtent: firstSliverHeight,
cacheExtent: firstSliverHeight,
visible: true,
);
// With RenderSliverFillRemainingWithScrollable:
// * The child has a minExtent of the remainingPaintExtent.
// * If not within the viewport but within the cacheExtent, the child has
// a maxExtent of the sliver's cacheExtent. Otherwise, the child has a
// maxExtent of the remainingPaintExtent
// * The sliver has a paintExtent of the child's minExtent or the
// remainingPaintExtent - whichever is smaller.
// * The sliver has a cacheExtent of either the viewportMainAxisExtent or
// the remainingCacheExtent - whichever is smaller.
final RenderSliverSingleBoxAdapter sliverFillRemaining = slivers[1] as RenderSliverSingleBoxAdapter;
double remainingPaintExtent = viewportHeight - firstSliverHeight;
double remainingCacheExtent = beginningViewportCacheExtent - firstSliverHeight;
double minExtentOfChild = remainingPaintExtent;
double maxExtentOfChild = remainingPaintExtent;
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: maxExtentOfChild,
minHeight: minExtentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: minExtentOfChild,
cacheExtent: remainingCacheExtent,
visible: true,
);
// Overscroll so first sliver is partially out of view.
root.offset = ViewportOffset.fixed(50);
pumpFrame();
remainingPaintExtent = viewportHeight - firstSliverHeight + 50;
remainingCacheExtent = beginningViewportCacheExtent - firstSliverHeight + 50;
minExtentOfChild = remainingPaintExtent;
maxExtentOfChild = remainingPaintExtent;
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: maxExtentOfChild,
minHeight: minExtentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: minExtentOfChild,
cacheExtent: remainingCacheExtent,
visible: true,
);
// Overscroll so only RenderSliverFillRemainingWithScrollable is visible.
root.offset = ViewportOffset.fixed(firstSliverHeight);
pumpFrame();
remainingPaintExtent = viewportHeight;
remainingCacheExtent = beginningViewportCacheExtent;
minExtentOfChild = remainingPaintExtent;
maxExtentOfChild = remainingPaintExtent;
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: maxExtentOfChild,
minHeight: minExtentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: minExtentOfChild,
cacheExtent: viewportHeight,
visible: true,
);
});
test('when scrolled into view', () {
// Viewport is 800x600
const double viewportHeight = 600;
const double viewportWidth = 800;
const double cacheExtent = 250.0;
const double beginningViewportCacheExtent = viewportHeight + cacheExtent;
const double firstSliverHeight = beginningViewportCacheExtent;
const double sliverFillRemainingChildHeight = 100.0;
final List<RenderSliver> slivers = <RenderSliver>[
RenderSliverToBoxAdapter(
child: RenderSizedBox(const Size(400.0, firstSliverHeight)),
),
RenderSliverFillRemainingWithScrollable(
child: RenderSizedBox(const Size(100.0, sliverFillRemainingChildHeight)),
)
];
final RenderViewport root = RenderViewport(
crossAxisDirection: AxisDirection.right,
offset: ViewportOffset.zero(),
cacheExtent: cacheExtent,
children: slivers,
);
layout(root);
final RenderSliver firstVisibleSliver = slivers[0];
expectSliverConstraints(
sliver: firstVisibleSliver,
cacheOrigin: 0.0,
remainingPaintExtent: viewportHeight,
remainingCacheExtent: beginningViewportCacheExtent,
scrollOffset: 0.0,
);
expectSliverGeometry(
sliver: firstVisibleSliver,
paintExtent: viewportHeight,
cacheExtent: firstSliverHeight,
visible: true,
);
// With RenderSliverFillRemainingWithScrollable:
// * The child has a minExtent of the remainingPaintExtent.
// * If not within the viewport but within the cacheExtent, the child has
// a maxExtent of the sliver's cacheExtent. Otherwise, the child has a
// maxExtent of the remainingPaintExtent
// * The sliver has a paintExtent of the child's minExtent or the
// remainingPaintExtent - whichever is smaller.
// * The sliver has a cacheExtent of either the viewportMainAxisExtent or
// the remainingCacheExtent - whichever is smaller.
final RenderSliverSingleBoxAdapter sliverFillRemaining = slivers[1] as RenderSliverSingleBoxAdapter;
double remainingPaintExtent = 0;
double remainingCacheExtent = 0;
double minExtentOfChild = remainingPaintExtent;
double maxExtentOfChild = remainingPaintExtent;
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: maxExtentOfChild,
minHeight: minExtentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: minExtentOfChild,
cacheExtent: remainingCacheExtent,
visible: false,
);
// Scroll so RenderSliverFillRemainingWithScrollable is not within
// viewport, but is within remainingCacheExtent.
root.offset = ViewportOffset.fixed(cacheExtent);
pumpFrame();
remainingPaintExtent = 0;
remainingCacheExtent = cacheExtent;
minExtentOfChild = remainingPaintExtent;
// When RenderSliverFillRemainingWithScrollable is completely outside the
// viewport, but is within the remainingCacheExtent, the child has a
// maxExtent of the slivers's cacheExtent.
maxExtentOfChild = remainingCacheExtent;
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: maxExtentOfChild,
minHeight: minExtentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: minExtentOfChild,
cacheExtent: remainingCacheExtent,
visible: false,
);
// Scroll so RenderSliverFillRemainingWithScrollable is partially within
// viewport.
root.offset = ViewportOffset.fixed(cacheExtent + 50);
pumpFrame();
remainingPaintExtent = 50;
remainingCacheExtent = cacheExtent + 50;
minExtentOfChild = remainingPaintExtent;
maxExtentOfChild = remainingPaintExtent;
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: maxExtentOfChild,
minHeight: minExtentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: minExtentOfChild,
cacheExtent: remainingCacheExtent,
visible: true,
);
// Scroll so RenderSliverFillRemainingWithScrollable takes the entire
// viewport.
root.offset = ViewportOffset.fixed(firstSliverHeight);
pumpFrame();
remainingPaintExtent = viewportHeight;
remainingCacheExtent = beginningViewportCacheExtent;
minExtentOfChild = remainingPaintExtent;
maxExtentOfChild = remainingPaintExtent;
expectSliverConstraints(
sliver: sliverFillRemaining,
cacheOrigin: 0.0,
remainingPaintExtent: remainingPaintExtent,
remainingCacheExtent: remainingCacheExtent,
scrollOffset: 0.0,
);
expectSliverChildConstraints(
sliver: sliverFillRemaining,
maxHeight: maxExtentOfChild,
minHeight: minExtentOfChild,
maxWidth: viewportWidth,
minWidth: viewportWidth,
);
expectSliverGeometry(
sliver: sliverFillRemaining,
paintExtent: minExtentOfChild,
cacheExtent: viewportHeight,
visible: true,
);
});
});
}
void expectSliverConstraints({
@ -898,6 +1806,19 @@ void expectSliverGeometry({
expect(sliver.geometry!.visible, visible, reason: 'visible');
}
void expectSliverChildConstraints({
required RenderSliverSingleBoxAdapter sliver,
required double maxWidth,
required double maxHeight,
required double minWidth,
required double minHeight,
}) {
expect(sliver.child!.constraints.maxWidth, maxWidth, reason: 'maxWidth');
expect(sliver.child!.constraints.maxHeight, maxHeight, reason: 'maxHeight');
expect(sliver.child!.constraints.minWidth, minWidth, reason: 'minWidth');
expect(sliver.child!.constraints.minHeight, minHeight, reason: 'minHeight');
}
class TestRenderSliverBoxChildManager extends RenderSliverBoxChildManager {
TestRenderSliverBoxChildManager({
required this.children,

386
packages/flutter/test/widgets/sliver_fill_remaining_test.dart
View file

@ -139,6 +139,132 @@ void main() {
expect(controller.offset, 150.0);
expect(find.byType(Container), findsOneWidget);
});
group('has correct semantics when', () {
testWidgets('within viewport', (WidgetTester tester) async {
// Viewport is 800x600
const double viewportHeight = 600;
const double cacheExtent = 250;
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
Directionality(
textDirection: TextDirection.ltr,
child: CustomScrollView(
cacheExtent: cacheExtent,
slivers: <Widget>[
SliverToBoxAdapter(
child: Container(
color: Colors.amber,
height: viewportHeight - 100,
width: 150,
),
),
// This sliver is within viewport
const SliverFillRemaining(
child: SizedBox(
height: 100,
child: Text('Text in SliverFillRemaining'),
),
),
],
),
),
);
// When SliverFillRemaining is within the viewport, semantic nodes for
// it are created.
final SemanticsFinder textInSliverFillRemaining = find.semantics.byLabel(
'Text in SliverFillRemaining',
);
expect(textInSliverFillRemaining, findsOne);
expect(textInSliverFillRemaining, containsSemantics(isHidden: false));
handle.dispose();
});
testWidgets('outside of viewport but within cache extent', (WidgetTester tester) async {
// Viewport is 800x600
const double viewportHeight = 600;
const double cacheExtent = 250;
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
Directionality(
textDirection: TextDirection.ltr,
child: CustomScrollView(
cacheExtent: cacheExtent,
slivers: <Widget>[
// This sliver takes up entire viewport and leaves 250 remaining cacheExtent
SliverToBoxAdapter(
child: Container(
color: Colors.amber,
height: viewportHeight,
width: 150,
),
),
// This sliver is not within viewport but is within remaining cacheExtent
const SliverFillRemaining(
child: SizedBox(
height: 100,
child: Text('Text in SliverFillRemaining'),
),
),
],
),
),
);
// When SliverFillRemaining is not in viewport, but is within
// cacheExtent, hidden semantic nodes for it are created.
final SemanticsFinder textInSliverFillRemaining = find.semantics.byLabel(
'Text in SliverFillRemaining',
);
expect(textInSliverFillRemaining, findsOne);
expect(textInSliverFillRemaining, containsSemantics(isHidden: true));
handle.dispose();
});
testWidgets('outside of viewport and not within cache extent', (WidgetTester tester) async {
// Viewport is 800x600
const double viewportHeight = 600;
const double cacheExtent = 250;
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
Directionality(
textDirection: TextDirection.ltr,
child: CustomScrollView(
cacheExtent: cacheExtent,
slivers: <Widget>[
// This sliver takes up entire viewport and leaves 0 remaining cacheExtent
SliverToBoxAdapter(
child: Container(
color: Colors.amber,
height: viewportHeight + cacheExtent,
width: 150,
),
),
// This sliver is not within viewport and not within remaining cacheExtent
const SliverFillRemaining(
child: SizedBox(
height: 100,
child: Text('Text in SliverFillRemaining'),
),
),
],
),
),
);
// When SliverFillRemaining is not in viewport and not within
// cacheExtent, semantic nodes are not created.
final SemanticsFinder textInSliverFillRemaining = find.semantics.byLabel(
'Text in SliverFillRemaining',
);
expect(textInSliverFillRemaining, findsNothing);
handle.dispose();
});
});
});
group('hasScrollBody: false', () {
@ -357,6 +483,135 @@ void main() {
expect(tester.getCenter(button).dx, equals(400.0));
}, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.macOS }));
group('has correct semantics when', () {
testWidgets('within viewport', (WidgetTester tester) async {
// Viewport is 800x600
const double viewportHeight = 600;
const double cacheExtent = 250;
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
Directionality(
textDirection: TextDirection.ltr,
child: CustomScrollView(
cacheExtent: cacheExtent,
slivers: <Widget>[
SliverToBoxAdapter(
child: Container(
color: Colors.amber,
height: viewportHeight - 100,
width: 150,
),
),
// This sliver is within viewport
const SliverFillRemaining(
hasScrollBody: false,
child: SizedBox(
height: 100,
child: Text('Text in SliverFillRemaining'),
),
),
],
),
),
);
// When SliverFillRemaining is within the viewport, semantic nodes for
// it are created.
final SemanticsFinder textInSliverFillRemaining = find.semantics.byLabel(
'Text in SliverFillRemaining',
);
expect(textInSliverFillRemaining, findsOne);
expect(textInSliverFillRemaining, containsSemantics(isHidden: false));
handle.dispose();
});
testWidgets('outside of viewport but within cache extent', (WidgetTester tester) async {
// Viewport is 800x600
const double viewportHeight = 600;
const double cacheExtent = 250;
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
Directionality(
textDirection: TextDirection.ltr,
child: CustomScrollView(
cacheExtent: cacheExtent,
slivers: <Widget>[
// This sliver takes up entire viewport and leaves 250 remaining cacheExtent
SliverToBoxAdapter(
child: Container(
color: Colors.amber,
height: viewportHeight,
width: 150,
),
),
// This sliver is not within viewport but is within remaining cacheExtent
const SliverFillRemaining(
hasScrollBody: false,
child: SizedBox(
height: 100,
child: Text('Text in SliverFillRemaining'),
),
),
],
),
),
);
// When SliverFillRemaining is not in viewport, but is within
// cacheExtent, hidden semantic nodes for it are created.
final SemanticsFinder textInSliverFillRemaining = find.semantics.byLabel(
'Text in SliverFillRemaining',
);
expect(textInSliverFillRemaining, findsOne);
expect(textInSliverFillRemaining, containsSemantics(isHidden: true));
handle.dispose();
});
testWidgets('outside of viewport and not within cache extent', (WidgetTester tester) async {
// Viewport is 800x600
const double viewportHeight = 600;
const double cacheExtent = 250;
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
Directionality(
textDirection: TextDirection.ltr,
child: CustomScrollView(
cacheExtent: cacheExtent,
slivers: <Widget>[
// This sliver takes up entire viewport and leaves 0 remaining cacheExtent
SliverToBoxAdapter(
child: Container(
color: Colors.amber,
height: viewportHeight + cacheExtent,
width: 150,
),
),
// This sliver is not within viewport and not within remaining cacheExtent
const SliverFillRemaining(
hasScrollBody: false,
child: SizedBox(
height: 100,
child: Text('Text in SliverFillRemaining'),
),
),
],
),
),
);
// When SliverFillRemaining is not in viewport and not within
// cacheExtent, semantic nodes are not created.
final SemanticsFinder textInSliverFillRemaining = find.semantics.byLabel(
'Text in SliverFillRemaining',
);
expect(textInSliverFillRemaining, findsNothing);
handle.dispose();
});
});
group('fillOverscroll: true, relevant platforms', () {
testWidgets('child without size is sized by extent and overscroll', (WidgetTester tester) async {
final List<Widget> slivers = <Widget>[
@ -650,6 +905,137 @@ void main() {
expect(tester.getBottomLeft(button).dy, equals(600.0));
expect(tester.getCenter(button).dx, equals(400.0));
}, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.macOS }));
group('has correct semantics when', () {
testWidgets('within viewport', (WidgetTester tester) async {
// Viewport is 800x600
const double viewportHeight = 600;
const double cacheExtent = 250;
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
Directionality(
textDirection: TextDirection.ltr,
child: CustomScrollView(
cacheExtent: cacheExtent,
slivers: <Widget>[
SliverToBoxAdapter(
child: Container(
color: Colors.amber,
height: viewportHeight - 100,
width: 150,
),
),
// This sliver is within viewport
const SliverFillRemaining(
hasScrollBody: false,
fillOverscroll: true,
child: SizedBox(
height: 100,
child: Text('Text in SliverFillRemaining'),
),
),
],
),
),
);
// When SliverFillRemaining is within the viewport, semantic nodes for
// it are created.
final SemanticsFinder textInSliverFillRemaining = find.semantics.byLabel(
'Text in SliverFillRemaining',
);
expect(textInSliverFillRemaining, findsOne);
expect(textInSliverFillRemaining, containsSemantics(isHidden: false));
handle.dispose();
}, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.macOS }));
testWidgets('outside of viewport but within cache extent', (WidgetTester tester) async {
// Viewport is 800x600
const double viewportHeight = 600;
const double cacheExtent = 250;
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
Directionality(
textDirection: TextDirection.ltr,
child: CustomScrollView(
cacheExtent: cacheExtent,
slivers: <Widget>[
// This sliver takes up entire viewport and leaves 250 remaining cacheExtent
SliverToBoxAdapter(
child: Container(
color: Colors.amber,
height: viewportHeight,
width: 150,
),
),
// This sliver is not within viewport but is within remaining cacheExtent
const SliverFillRemaining(
hasScrollBody: false,
fillOverscroll: true,
child: SizedBox(
height: 100,
child: Text('Text in SliverFillRemaining'),
),
),
],
),
),
);
// When SliverFillRemaining is not in viewport, but is within
// cacheExtent, hidden semantic nodes for it are created.
final SemanticsFinder textInSliverFillRemaining = find.semantics.byLabel(
'Text in SliverFillRemaining',
);
expect(textInSliverFillRemaining, findsOne);
expect(textInSliverFillRemaining, containsSemantics(isHidden: true));
handle.dispose();
}, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.macOS }));
testWidgets('outside of viewport and not within cache extent', (WidgetTester tester) async {
// Viewport is 800x600
const double viewportHeight = 600;
const double cacheExtent = 250;
final SemanticsHandle handle = tester.ensureSemantics();
await tester.pumpWidget(
Directionality(
textDirection: TextDirection.ltr,
child: CustomScrollView(
cacheExtent: cacheExtent,
slivers: <Widget>[
// This sliver takes up entire viewport and leaves 0 remaining cacheExtent
SliverToBoxAdapter(
child: Container(
color: Colors.amber,
height: viewportHeight + cacheExtent,
width: 150,
),
),
// This sliver is not within viewport and not within remaining cacheExtent
const SliverFillRemaining(
hasScrollBody: false,
fillOverscroll: true,
child: SizedBox(
height: 100,
child: Text('Text in SliverFillRemaining'),
),
),
],
),
),
);
// When SliverFillRemaining is not in viewport and not within
// cacheExtent, semantic nodes are not created.
final SemanticsFinder textInSliverFillRemaining = find.semantics.byLabel(
'Text in SliverFillRemaining',
);
expect(textInSliverFillRemaining, findsNothing);
handle.dispose();
}, variant: const TargetPlatformVariant(<TargetPlatform>{ TargetPlatform.iOS, TargetPlatform.macOS }));
});
});
group('fillOverscroll: true, is ignored on irrelevant platforms', () {