Struct RenderPositionedBox 

pub struct RenderPositionedBox { /* private fields */ }

Positions its child using an AlignmentGeometry.

For example, to align a box at the bottom right, you would pass this box a tight constraint that is bigger than the child’s natural size, with an alignment of Alignment::BOTTOM_RIGHT.

By default, sizes to be as big as possible in both axes. If either axis is unconstrained, then in that direction it will be sized to fit the child’s dimensions. Using width_factor and height_factor you can force this latter behavior in all cases.

Implementations

impl RenderPositionedBox

pub fn new( app: &mut App, alignment: AlignmentGeometry, text_direction: Option<TextDirection>, width_factor: Option<f64>, height_factor: Option<f64>, child: Option<AnyRenderBox>, ) -> RenderHandle<Self>

Creates a render object that positions its child.

width_factor and height_factor must be non-negative when given.

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

If non-null, sets its width to the child’s width multiplied by this factor.

Can be both greater and less than 1.0 but must be positive.

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

Sets width_factor.

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

If non-null, sets its height to the child’s height multiplied by this factor.

Can be both greater and less than 1.0 but must be positive.

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

Sets height_factor.

Trait Implementations

impl RenderAligningShiftedBox for RenderPositionedBox

fn aligning_data( self: RenderHandle<Self>, app: &App, ) -> &RenderAligningShiftedBoxData

Mixin field access.

fn aligning_data_mut( self: RenderHandle<Self>, app: &mut App, ) -> &mut RenderAligningShiftedBoxData

See aligning_data.

fn resolved_alignment(self: RenderHandle<Self>, app: &mut App) -> Alignment

The alignment resolved against text_direction.

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

fn alignment(self: RenderHandle<Self>, app: &App) -> AlignmentGeometry

How to align the child.

fn set_alignment( self: RenderHandle<Self>, app: &mut App, value: AlignmentGeometry, )

Sets alignment.

fn text_direction(self: RenderHandle<Self>, app: &App) -> Option<TextDirection>

The text direction with which to resolve alignment.

fn set_text_direction( self: RenderHandle<Self>, app: &mut App, value: Option<TextDirection>, )

Sets text_direction.

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

Apply the current alignment to the child.

impl RenderBox for RenderPositionedBox

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

Computes the value returned by get_dry_baseline.

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

The box constraints most recently supplied by the parent.

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

Installs BoxParentData unless the child already has it.

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 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 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 RenderObject for RenderPositionedBox

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

Calls visitor for each immediate child.

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 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 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.

impl RenderObjectWithChildMixin for RenderPositionedBox

type ChildType = AnyRenderBox

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

fn child_data( self: RenderHandle<Self>, app: &App, ) -> &RenderObjectWithChildData<AnyRenderBox>

Mixin field access.

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

See child_data.

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

The render object’s unique child.

fn set_child( self: RenderHandle<Self>, app: &mut App, value: Option<Self::ChildType>, )

Sets the unique child, adopting or dropping as Flutter’s setter does.

impl RenderShiftedBox for RenderPositionedBox

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

The child’s minimum intrinsic width, or 0 without a child.

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

The child’s maximum intrinsic width, or 0 without a child.

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

The child’s minimum intrinsic height, or 0 without a child.

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

The child’s maximum intrinsic height, or 0 without a child.

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

The child’s baseline shifted by the child’s paint offset, or none without a child.

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

The child’s dry baseline at this box’s constraints. The base applies no transform; subclasses override to add their offset.

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

Hit tests the child at its parent-data offset.

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

Paints the child at its parent-data offset.