Struct RenderSliverFixedExtentList 

pub struct RenderSliverFixedExtentList { /* private fields */ }

A sliver that places multiple box children with the same main axis extent in a linear array.

RenderSliverFixedExtentList places its children in a linear array along the main axis starting at offset zero and without gaps. Each child is forced to have the item_extent in the main axis and the crate::SliverConstraints::cross_axis_extent in the cross axis.

RenderSliverFixedExtentList is more efficient than crate::RenderSliverList because it does not need to perform layout on its children to obtain their extent in the main axis.

Implementations

impl RenderSliverFixedExtentList

pub fn new( app: &mut App, child_manager: Rc<dyn RenderSliverBoxChildManager>, item_extent: f64, ) -> RenderHandle<RenderSliverFixedExtentList>

Creates a sliver that contains multiple box children that have a given extent in the main axis.

pub fn set_item_extent(self: RenderHandle<Self>, app: &mut App, value: f64)

Sets RenderSliverFixedExtentBoxAdaptor::item_extent.

Trait Implementations

impl ContainerRenderObjectMixin for RenderSliverFixedExtentList

type ChildType = AnyRenderBox

Flutter’s ChildType: the protocol of this render object’s children.

type ParentDataType = SliverMultiBoxAdaptorParentData

Flutter’s ParentDataType: the parent data this render object installs on its children.

fn container_data( self: RenderHandle<Self>, app: &App, ) -> &ContainerRenderObjectData<AnyRenderBox>

Mixin field access.

fn container_data_mut( self: RenderHandle<Self>, app: &mut App, ) -> &mut ContainerRenderObjectData<AnyRenderBox>

See container_data.

fn insert( self: RenderHandle<Self>, app: &mut App, child: AnyRenderBox, after: Option<AnyRenderBox>, )

Insert child into this render object’s child list after the given child.

fn move_child( self: RenderHandle<Self>, app: &mut App, child: AnyRenderBox, after: Option<AnyRenderBox>, )

Move the given child in the child list to be after another child.

fn remove(self: RenderHandle<Self>, app: &mut App, child: AnyRenderBox)

Remove this child from the child list.

fn remove_all(self: RenderHandle<Self>, app: &mut App)

Remove all their children from this render object’s child list.

fn child_count(self: RenderHandle<Self>, app: &App) -> usize

The number of children.

fn add(self: RenderHandle<Self>, app: &mut App, child: Self::ChildType)

Append child to the end of this render object’s child list.

fn add_all( self: RenderHandle<Self>, app: &mut App, children: Option<Vec<Self::ChildType>>, )

Add all the children to the end of this render object’s child list.

fn did_attach( self: RenderHandle<Self>, app: &mut App, owner: Handle<PipelineOwner>, )

The body of Flutter’s attach override: attaches every child in the list.

fn did_detach(self: RenderHandle<Self>, app: &mut App)

The body of Flutter’s detach override: detaches every child in the list.

fn redepth_children(self: RenderHandle<Self>, app: &mut App)

Flutter’s redepthChildren: walks the child list.

fn visit_children( self: RenderHandle<Self>, app: &App, visitor: &mut dyn FnMut(AnyRenderObject), )

Flutter’s visitChildren: walks the child list.

fn first_child(self: RenderHandle<Self>, app: &App) -> Option<Self::ChildType>

The first child in the child list.

fn last_child(self: RenderHandle<Self>, app: &App) -> Option<Self::ChildType>

The last child in the child list.

fn child_before( self: RenderHandle<Self>, app: &App, child: Self::ChildType, ) -> Option<Self::ChildType>

The previous child before the given child in the child list.

fn child_after( self: RenderHandle<Self>, app: &App, child: Self::ChildType, ) -> Option<Self::ChildType>

The next child after the given child in the child list.

fn children_as_list(self: RenderHandle<Self>, app: &App) -> Vec<Self::ChildType>

Returns a list containing the children of this render object.

impl RenderObject for RenderSliverFixedExtentList

fn render_object_data(self: RenderHandle<Self>, app: &App) -> &RenderObjectData

Mixin field access.

fn render_object_data_mut( self: RenderHandle<Self>, app: &mut App, ) -> &mut RenderObjectData

See render_object_data.

fn setup_parent_data( self: RenderHandle<Self>, app: &mut App, child: AnyRenderObject, )

Sets up parent data for child if it has none.

fn visit_children( self: RenderHandle<Self>, app: &App, visitor: &mut dyn FnMut(AnyRenderObject), )

Calls visitor for each immediate child.

fn did_attach( self: RenderHandle<Self>, app: &mut App, owner: Handle<PipelineOwner>, )

The body of Flutter’s attach override after super.attach(owner); the base body has already run. The default attaches the children reported by visit_children.

fn did_detach(self: RenderHandle<Self>, app: &mut App)

The body of Flutter’s detach override after super.detach(). The default detaches the children reported by visit_children.

fn redepth_children(self: RenderHandle<Self>, app: &mut App)

Adjusts the depth of each child reported by visit_children.

fn apply_paint_transform( self: RenderHandle<Self>, app: &App, child: AnyRenderObject, transform: &mut Matrix4, )

Applies the transform that would be applied when painting the given child to the given matrix.

fn paint( self: RenderHandle<Self>, app: &mut App, context: &mut PaintingContext, offset: Offset, )

Paint this render object into the given context at the given offset.

fn perform_layout(self: RenderHandle<Self>, app: &mut App)

Do the work of computing the layout for this render object.

fn as_render_object(self: RenderHandle<Self>, app: &App) -> AnyRenderObject

Dart’s implicit upcast of a concrete render object to RenderObject: this object’s type-erased handle, through the vtable the protocol recorded when it created it.

fn perform_resize(self: RenderHandle<Self>, _app: &mut App)

Updates the render object’s size using only the constraints.

fn sized_by_parent(self: RenderHandle<Self>, _app: &App) -> bool

Whether the constraints are the only input to the sizing algorithm.

fn is_repaint_boundary(self: RenderHandle<Self>, _app: &App) -> bool

Whether this render object repaints separately from its parent.

fn always_needs_compositing(self: RenderHandle<Self>, _app: &App) -> bool

Whether this render object always needs compositing.

fn mouse_tracker_annotation( self: RenderHandle<Self>, _app: &App, ) -> Option<MouseTrackerAnnotation>

Dart’s this is MouseTrackerAnnotation: the annotation this render object implements, read live each time the mouse tracker consults it. None for a render object that is not an annotation, which is the default.

fn update_composited_layer( self: RenderHandle<Self>, app: &mut App, old_layer: Option<AnyOffsetLayer>, ) -> AnyOffsetLayer

Update the composited layer owned by this render object.

fn show_on_screen( self: RenderHandle<Self>, app: &mut App, descendant: Option<AnyRenderObject>, rect: Option<Rect>, duration: Duration, curve: Rc<dyn Curve>, )

Attempt to make (a portion of) this or a descendant RenderObject visible on screen.

fn interface(self: RenderHandle<Self>, id: TypeId) -> Option<Box<dyn Any>>

Dart’s object is RenderAbstractViewport for any interface: the erased handle of the interface id names, if this type implements it.

fn dispose(self: RenderHandle<Self>, app: &mut App)

Release any resources held by this render object.

impl RenderSliver for RenderSliverFixedExtentList

fn render_sliver_data(self: RenderHandle<Self>, app: &App) -> &RenderSliverData

Mixin field access.

fn render_sliver_data_mut( self: RenderHandle<Self>, app: &mut App, ) -> &mut RenderSliverData

See render_sliver_data.

fn hit_test_children( self: RenderHandle<Self>, app: &mut App, result: &mut SliverHitTestResult<'_>, main_axis_position: f64, cross_axis_position: f64, ) -> bool

Override this method to check whether any children are located at the given position.

fn child_main_axis_position( self: RenderHandle<Self>, app: &App, child: AnyRenderObject, ) -> f64

Returns the distance from the leading visible edge of the sliver to the side of the given child closest to that edge.

fn child_scroll_offset( self: RenderHandle<Self>, app: &App, child: AnyRenderObject, ) -> Option<f64>

Returns the scroll offset for the leading edge of the given child.

fn constraints(self: RenderHandle<Self>, app: &App) -> SliverConstraints

The sliver constraints most recently supplied by the parent.

fn geometry(self: RenderHandle<Self>, app: &App) -> SliverGeometry

The amount of space this sliver occupies.

fn set_geometry( self: RenderHandle<Self>, app: &mut App, geometry: SliverGeometry, )

Sets the geometry of this sliver. Call from RenderObject::perform_layout.

fn paint_bounds(self: RenderHandle<Self>, app: &App) -> Rect

An estimate of the bounds within which this render object will paint: the paint extent along the main axis by the cross axis extent.

fn center_offset_adjustment(self: RenderHandle<Self>, _app: &App) -> f64

For a center sliver, the distance before the absolute zero scroll offset that this sliver can cover.

fn hit_test( self: RenderHandle<Self>, app: &mut App, result: &mut SliverHitTestResult<'_>, main_axis_position: f64, cross_axis_position: f64, ) -> bool

Determines the set of render objects located at the given position.

fn hit_test_self( self: RenderHandle<Self>, _app: &App, _main_axis_position: f64, _cross_axis_position: f64, ) -> bool

Override this method if this render object can be hit even if its children were not hit.

fn handle_event( self: RenderHandle<Self>, _app: &mut App, _event: &PointerEvent, _entry: &SliverHitTestEntry, )

Override to handle pointer events that hit this render object.

fn calculate_paint_offset( self: RenderHandle<Self>, _app: &App, constraints: SliverConstraints, from: f64, to: f64, ) -> f64

Computes the portion of the region from from to to that is visible, assuming that only the region from the SliverConstraints::scroll_offset that is SliverConstraints::remaining_paint_extent high is visible, and that the relationship between scroll offsets and paint offsets is linear.

fn calculate_cache_offset( self: RenderHandle<Self>, _app: &App, constraints: SliverConstraints, from: f64, to: f64, ) -> f64

Computes the portion of the region from from to to that is within the cache extent of the viewport, assuming that only the region from the SliverConstraints::cache_origin that is SliverConstraints::remaining_cache_extent high is visible, and that the relationship between scroll offsets and paint offsets is linear.

fn child_cross_axis_position( self: RenderHandle<Self>, _app: &App, _child: AnyRenderObject, ) -> f64

Returns the distance along the cross axis from the zero of the cross axis in this sliver’s paint coordinate space to the nearest side of the given child.

fn get_absolute_size_relative_to_origin( self: RenderHandle<Self>, app: &App, ) -> Size

This returns a Size with dimensions relative to the leading edge of the sliver, specifically the same offset that is given to the RenderObject::paint method. This means that the dimensions may be negative.

fn get_absolute_size(self: RenderHandle<Self>, app: &App) -> Size

This returns the absolute Size of the sliver.

fn get_max_paint_rect(self: RenderHandle<Self>, app: &App) -> Rect

Returns the Rect that covers the total paint extent of the sliver.

fn layout( self: RenderHandle<Self>, app: &mut App, constraints: SliverConstraints, parent_uses_size: bool, )

See AnyRenderSliver::layout.

fn as_sliver(self: RenderHandle<Self>) -> AnyRenderSliver

The type-erased RenderSliver handle. Free: the vtable is a const, and the id is copied.

fn as_object(self: RenderHandle<Self>) -> AnyRenderObject

The type-erased RenderObject handle, through as_sliver.

fn adopt_child(self: RenderHandle<Self>, app: &mut App, child: AnyRenderObject)

See AnyRenderObject::adopt_child.

fn drop_child(self: RenderHandle<Self>, app: &mut App, child: AnyRenderObject)

See AnyRenderObject::drop_child.

fn mark_needs_layout(self: RenderHandle<Self>, app: &mut App)

See AnyRenderObject::mark_needs_layout.

fn mark_needs_paint(self: RenderHandle<Self>, app: &mut App)

See AnyRenderObject::mark_needs_paint.

fn mark_needs_composited_layer_update(self: RenderHandle<Self>, app: &mut App)

See AnyRenderObject::mark_needs_composited_layer_update.

fn schedule_initial_layout(self: RenderHandle<Self>, app: &mut App)

See AnyRenderObject::schedule_initial_layout.

fn parent(self: RenderHandle<Self>, app: &App) -> Option<AnyRenderObject>

See AnyRenderObject::parent.

fn owner(self: RenderHandle<Self>, app: &App) -> Option<Handle<PipelineOwner>>

See AnyRenderObject::owner.

fn attached(self: RenderHandle<Self>, app: &App) -> bool

See AnyRenderObject::attached.

fn debug_needs_layout(self: RenderHandle<Self>, app: &App) -> bool

See AnyRenderObject::debug_needs_layout.

impl RenderSliverFixedExtentBoxAdaptor for RenderSliverFixedExtentList

fn fixed_extent_data( self: RenderHandle<Self>, app: &App, ) -> &RenderSliverFixedExtentBoxAdaptorData

Mixin field access.

fn fixed_extent_data_mut( self: RenderHandle<Self>, app: &mut App, ) -> &mut RenderSliverFixedExtentBoxAdaptorData

See fixed_extent_data.

fn item_extent(self: RenderHandle<Self>, app: &App) -> Option<f64>

The main-axis extent of each item.

fn item_extent_builder( self: RenderHandle<Self>, app: &App, ) -> Option<ItemExtentBuilder>

The main-axis extent builder of each item.

fn layout_dimensions( self: RenderHandle<Self>, app: &App, ) -> SliverLayoutDimensions

The layout dimensions for the sliver.

fn index_to_layout_offset( self: RenderHandle<Self>, app: &App, index: i32, ) -> f64

The layout offset for the child with the given index.

fn get_min_child_index_for_scroll_offset( self: RenderHandle<Self>, app: &App, scroll_offset: f64, ) -> i32

The minimum child index that is visible at the given scroll offset.

fn get_max_child_index_for_scroll_offset( self: RenderHandle<Self>, app: &App, scroll_offset: f64, ) -> i32

The maximum child index that is visible at the given scroll offset.

fn child_index_for_scroll_offset( self: RenderHandle<Self>, app: &App, scroll_offset: f64, builder: &ItemExtentBuilder, ) -> i32

Flutter’s _getChildIndexForScrollOffset.

fn estimate_max_scroll_offset( self: RenderHandle<Self>, app: &App, constraints: SliverConstraints, first_index: Option<i32>, last_index: Option<i32>, leading_scroll_offset: Option<f64>, trailing_scroll_offset: Option<f64>, ) -> f64

Called to estimate the total scrollable extents of this object.

fn compute_max_scroll_offset( self: RenderHandle<Self>, app: &mut App, _constraints: SliverConstraints, ) -> f64

Called to obtain a precise measure of the total scrollable extents of this object.

fn child_constraints( self: RenderHandle<Self>, app: &App, index: i32, ) -> BoxConstraints

Flutter’s _getChildConstraints.

fn paint_extent_of( self: RenderHandle<Self>, app: &App, child: AnyRenderBox, ) -> f64

The body of Flutter’s paintExtentOf override.

fn perform_layout(self: RenderHandle<Self>, app: &mut App)

The body of Flutter’s performLayout override.

impl RenderSliverHelpers for RenderSliverFixedExtentList

fn hit_test_box_child( self: RenderHandle<Self>, app: &mut App, result: &mut BoxHitTestResult<'_>, child: AnyRenderBox, main_axis_position: f64, cross_axis_position: f64, ) -> bool

Utility function for RenderSliver::hit_test_children for use when the children are crate::RenderBox widgets.

fn apply_paint_transform_for_box_child( self: RenderHandle<Self>, app: &App, child: AnyRenderBox, transform: &mut Matrix4, )

Utility function for RenderObject::apply_paint_transform for use when the children are crate::RenderBox widgets.

impl RenderSliverMultiBoxAdaptor for RenderSliverFixedExtentList

fn adaptor_data( self: RenderHandle<Self>, app: &App, ) -> &RenderSliverMultiBoxAdaptorData

Mixin field access.

fn adaptor_data_mut( self: RenderHandle<Self>, app: &mut App, ) -> &mut RenderSliverMultiBoxAdaptorData

See adaptor_data.

fn paint_extent_of( self: RenderHandle<Self>, app: &App, child: AnyRenderBox, ) -> f64

Returns the dimension of the given child in the main axis, as given by the child’s size.

fn child_manager( self: RenderHandle<Self>, app: &App, ) -> Rc<dyn RenderSliverBoxChildManager>

The delegate that manages the children of this object.

fn setup_parent_data( self: RenderHandle<Self>, app: &mut App, child: AnyRenderObject, )

The body of Flutter’s setupParentData override.

fn debug_child_integrity_enabled(self: RenderHandle<Self>, app: &App) -> bool

Whether the integrity check is enabled.

fn set_debug_child_integrity_enabled( self: RenderHandle<Self>, app: &mut App, enabled: bool, )

Sets debug_child_integrity_enabled, immediately performing an integrity check.

fn debug_assert_child_list_locked(self: RenderHandle<Self>, app: &App) -> bool

Flutter’s _debugAssertChildListLocked.

fn debug_verify_child_order(self: RenderHandle<Self>, app: &App) -> bool

Verify that the child list index is in strictly increasing order.

fn insert( self: RenderHandle<Self>, app: &mut App, child: AnyRenderBox, after: Option<AnyRenderBox>, )

The body of Flutter’s insert override.

fn did_adopt_child(self: RenderHandle<Self>, app: &mut App, child: AnyRenderBox)

The body of Flutter’s adoptChild override, run after a child joins the child list.

fn move_child( self: RenderHandle<Self>, app: &mut App, child: AnyRenderBox, after: Option<AnyRenderBox>, )

The body of Flutter’s move override.

fn remove(self: RenderHandle<Self>, app: &mut App, child: AnyRenderBox)

The body of Flutter’s remove override.

fn remove_all(self: RenderHandle<Self>, app: &mut App)

The body of Flutter’s removeAll override.

fn keep_alive_children(self: RenderHandle<Self>, app: &App) -> Vec<AnyRenderBox>

The children currently held in the keep-alive bucket, in insertion order.

fn create_or_obtain_child( self: RenderHandle<Self>, app: &mut App, index: i32, after: Option<AnyRenderBox>, )

Flutter’s _createOrObtainChild.

fn destroy_or_cache_child( self: RenderHandle<Self>, app: &mut App, child: AnyRenderBox, )

Flutter’s _destroyOrCacheChild.

fn did_attach( self: RenderHandle<Self>, app: &mut App, owner: Handle<PipelineOwner>, )

The body of Flutter’s attach override: attaches the kept-alive children too.

fn did_detach(self: RenderHandle<Self>, app: &mut App)

The body of Flutter’s detach override: detaches the kept-alive children too.

fn redepth_children(self: RenderHandle<Self>, app: &mut App)

The body of Flutter’s redepthChildren override.

fn visit_children( self: RenderHandle<Self>, app: &App, visitor: &mut dyn FnMut(AnyRenderObject), )

The body of Flutter’s visitChildren override: visits the kept-alive children too.

fn add_initial_child( self: RenderHandle<Self>, app: &mut App, index: i32, layout_offset: f64, ) -> bool

Called during layout to create and add the child with the given index and scroll offset.

fn insert_and_layout_leading_child( self: RenderHandle<Self>, app: &mut App, child_constraints: BoxConstraints, parent_uses_size: bool, ) -> Option<AnyRenderBox>

Called during layout to create, add, and lay out the child before ContainerRenderObjectMixin::first_child.

fn insert_and_layout_child( self: RenderHandle<Self>, app: &mut App, child_constraints: BoxConstraints, after: Option<AnyRenderBox>, parent_uses_size: bool, ) -> Option<AnyRenderBox>

Called during layout to create, add, and lay out the child after the given child.

fn calculate_leading_garbage( self: RenderHandle<Self>, app: &App, first_index: i32, ) -> usize

Returns the number of children preceding the first_index that need to be garbage collected.

fn calculate_trailing_garbage( self: RenderHandle<Self>, app: &App, last_index: i32, ) -> usize

Returns the number of children following the last_index that need to be garbage collected.

fn collect_garbage( self: RenderHandle<Self>, app: &mut App, leading_garbage: usize, trailing_garbage: usize, )

Called after layout with the number of children that can be garbage collected at the head and tail of the child list.

fn index_of(self: RenderHandle<Self>, app: &App, child: AnyRenderBox) -> i32

Returns the index of the given child, as given by the SliverMultiBoxAdaptorParentData::index field of the child’s parent data.

fn hit_test_children( self: RenderHandle<Self>, app: &mut App, result: &mut SliverHitTestResult<'_>, main_axis_position: f64, cross_axis_position: f64, ) -> bool

The body of Flutter’s hitTestChildren override.

fn child_main_axis_position( self: RenderHandle<Self>, app: &App, child: AnyRenderObject, ) -> f64

The body of Flutter’s childMainAxisPosition override.

fn child_scroll_offset( self: RenderHandle<Self>, app: &App, child: AnyRenderObject, ) -> Option<f64>

The body of Flutter’s childScrollOffset override.

fn paints_child( self: RenderHandle<Self>, app: &App, child: AnyRenderBox, ) -> bool

Whether the given child is painted, i.e. it is reified and not kept alive off-screen.

fn apply_paint_transform( self: RenderHandle<Self>, app: &App, child: AnyRenderObject, transform: &mut Matrix4, )

The body of Flutter’s applyPaintTransform override.

fn paint( self: RenderHandle<Self>, app: &mut App, context: &mut PaintingContext, offset: Offset, )

The body of Flutter’s paint override.

fn debug_assert_child_list_is_non_empty_and_contiguous( self: RenderHandle<Self>, app: &App, ) -> bool

Asserts that the reified child list is not empty and has a contiguous sequence of indices.

impl RenderSliverWithKeepAliveMixin for RenderSliverFixedExtentList

fn setup_parent_data( self: RenderHandle<Self>, app: &mut App, child: AnyRenderObject, )

Alerts the developer that the child’s parent data needs to embed a KeepAliveParentData.