Struct RenderCustomMultiChildLayoutBox 

pub struct RenderCustomMultiChildLayoutBox { /* private fields */ }

Defers the layout of multiple children to a delegate.

The delegate can determine the layout constraints for each child and can decide where to position each child. The delegate can also determine the size of the parent, but the size of the parent cannot depend on the sizes of the children.

Implementations

impl RenderCustomMultiChildLayoutBox

pub fn new( app: &mut App, delegate: Rc<dyn MultiChildLayoutDelegate>, ) -> RenderHandle<RenderCustomMultiChildLayoutBox>

Creates a render object that customizes the layout of multiple children.

Add children with add or add_all; Dart’s constructor takes them.

pub fn delegate( self: RenderHandle<Self>, app: &App, ) -> Rc<dyn MultiChildLayoutDelegate>

The delegate that controls the layout of the children.

pub fn set_delegate( self: RenderHandle<Self>, app: &mut App, new_delegate: Rc<dyn MultiChildLayoutDelegate>, )

Sets delegate.

Trait Implementations

impl ContainerRenderObjectMixin for RenderCustomMultiChildLayoutBox

type ChildType = AnyRenderBox

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

type ParentDataType = MultiChildLayoutParentData

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

The number of children.

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

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

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

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

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

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 RenderBox for RenderCustomMultiChildLayoutBox

fn render_box_data(self: RenderHandle<Self>, app: &App) -> &RenderBoxData

Mixin field access.

fn render_box_data_mut( self: RenderHandle<Self>, app: &mut App, ) -> &mut RenderBoxData

See render_box_data.

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

Installs BoxParentData unless the child already has it.

fn compute_min_intrinsic_width( self: RenderHandle<Self>, app: &mut App, height: f64, ) -> f64

Computes the value returned by get_min_intrinsic_width. Do not call this function directly, instead, call get_min_intrinsic_width.

fn compute_max_intrinsic_width( self: RenderHandle<Self>, app: &mut App, height: f64, ) -> f64

Computes the value returned by get_max_intrinsic_width. Do not call this function directly, instead, call get_max_intrinsic_width.

fn compute_min_intrinsic_height( self: RenderHandle<Self>, app: &mut App, width: f64, ) -> f64

Computes the value returned by get_min_intrinsic_height. Do not call this function directly, instead, call get_min_intrinsic_height.

fn compute_max_intrinsic_height( self: RenderHandle<Self>, app: &mut App, width: f64, ) -> f64

Computes the value returned by get_max_intrinsic_height. Do not call this function directly, instead, call get_max_intrinsic_height.

fn compute_dry_layout( self: RenderHandle<Self>, app: &mut App, constraints: BoxConstraints, ) -> Size

Computes the value returned by get_dry_layout. Do not call this function directly, instead, call get_dry_layout.

fn hit_test_children( self: RenderHandle<Self>, app: &mut App, result: &mut BoxHitTestResult<'_>, position: Offset, ) -> bool

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

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

The box constraints most recently supplied by the parent.

fn get_min_intrinsic_width( self: RenderHandle<Self>, app: &mut App, height: f64, ) -> f64

See AnyRenderBox::get_min_intrinsic_width.

fn get_max_intrinsic_width( self: RenderHandle<Self>, app: &mut App, height: f64, ) -> f64

See AnyRenderBox::get_max_intrinsic_width.

fn get_min_intrinsic_height( self: RenderHandle<Self>, app: &mut App, width: f64, ) -> f64

See AnyRenderBox::get_min_intrinsic_height.

fn get_max_intrinsic_height( self: RenderHandle<Self>, app: &mut App, width: f64, ) -> f64

See AnyRenderBox::get_max_intrinsic_height.

fn get_dry_layout( self: RenderHandle<Self>, app: &mut App, constraints: BoxConstraints, ) -> Size

See AnyRenderBox::get_dry_layout.

fn get_dry_baseline( self: RenderHandle<Self>, app: &mut App, constraints: BoxConstraints, baseline: TextBaseline, ) -> Option<f64>

See AnyRenderBox::get_dry_baseline.

fn compute_dry_baseline( self: RenderHandle<Self>, app: &mut App, constraints: BoxConstraints, baseline: TextBaseline, ) -> Option<f64>

Computes the value returned by get_dry_baseline.

fn debug_cannot_compute_dry_layout( self: RenderHandle<Self>, failure: DryLayoutFailure<'_>, )

Called from compute_dry_layout or compute_dry_baseline if this box does not support calculating a dry layout.

fn get_distance_to_baseline( self: RenderHandle<Self>, app: &mut App, baseline: TextBaseline, only_real: bool, ) -> Option<f64>

See AnyRenderBox::get_distance_to_baseline.

fn get_distance_to_actual_baseline( self: RenderHandle<Self>, app: &mut App, baseline: TextBaseline, ) -> Option<f64>

See AnyRenderBox::get_distance_to_actual_baseline.

fn compute_distance_to_actual_baseline( self: RenderHandle<Self>, app: &mut App, baseline: TextBaseline, ) -> Option<f64>

Returns the distance from the y-coordinate of the position of the box to the y-coordinate of the first given baseline in the box’s contents, if any, or None otherwise.

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

Mark this render object’s layout information as dirty.

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

Updates the box’s size using only the constraints.

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

The size of this box.

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

Multiply the transform from the parent’s coordinate system to this box’s coordinate system into the given transform.

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

An estimate of the bounds within which this render object will paint: the box’s own size.

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

Whether this render object has undergone layout and has a size.

fn handle_event( self: RenderHandle<Self>, app: &mut App, event: &PointerEvent, entry: &BoxHitTestEntry, )

Override this method to handle pointer events that hit this render object.

fn hit_test( self: RenderHandle<Self>, app: &mut App, result: &mut BoxHitTestResult<'_>, position: Offset, ) -> bool

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

fn hit_test_self( self: RenderHandle<Self>, _app: &App, _position: Offset, ) -> bool

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

fn set_size(self: RenderHandle<Self>, app: &mut App, size: Size)

Sets the size of this box. Call from RenderObject::perform_layout or RenderObject::perform_resize.

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

See AnyRenderBox::layout.

fn as_box(self: RenderHandle<Self>) -> AnyRenderBox

The type-erased RenderBox 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_box.

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_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 mark_needs_compositing_bits_update(self: RenderHandle<Self>, app: &mut App)

See AnyRenderObject::mark_needs_compositing_bits_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 RenderBoxContainerDefaultsMixin for RenderCustomMultiChildLayoutBox

fn default_compute_distance_to_first_actual_baseline( self: RenderHandle<Self>, app: &mut App, baseline: TextBaseline, ) -> Option<f64>

Returns the baseline of the first child with a baseline.

fn default_compute_distance_to_highest_actual_baseline( self: RenderHandle<Self>, app: &mut App, baseline: TextBaseline, ) -> Option<f64>

Returns the minimum baseline value among every child.

fn default_hit_test_children( self: RenderHandle<Self>, app: &mut App, result: &mut BoxHitTestResult<'_>, position: Offset, ) -> bool

Performs a hit test on each child by walking the child list backwards.

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

Paints each child by walking the child list forwards.

impl RenderObject for RenderCustomMultiChildLayoutBox

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

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

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

Sets up parent data for child if it has none.

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

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

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 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.