Struct RenderParagraph 

pub struct RenderParagraph { /* private fields */ }

A render object that displays a paragraph of text.

Dart’s constructor arguments beyond text and textDirection are the setters; add the inline children with add or add_all. The paragraph shapes against fonts when given, else the app-wide collection of PaintingBinding.

Implementations

impl RenderParagraph

pub fn new( app: &mut App, text: InlineSpanRef, text_direction: TextDirection, fonts: Option<Handle<FontCollection>>, ) -> RenderHandle<Self>

Creates a paragraph render object.

pub fn fonts(self: RenderHandle<Self>, app: &mut App) -> Handle<FontCollection>

The collection this paragraph shapes against: the override, else the app-wide one.

pub fn text(self: RenderHandle<Self>, app: &App) -> InlineSpanRef

The text to display.

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

Sets text.

pub fn text_align(self: RenderHandle<Self>, app: &App) -> TextAlign

How the text should be aligned horizontally.

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

Sets text_align.

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

The directionality of the text.

This decides how the TextAlign::Start, TextAlign::End, and TextAlign::Justify values of text_align are interpreted.

This is also used to disambiguate how to render bidirectional text. For example, if the text is an English phrase followed by a Hebrew phrase, in a TextDirection::Ltr context the English phrase will be on the left and the Hebrew phrase to its right, while in a TextDirection::Rtl context, the English phrase will be on the right and the Hebrew phrase on its left.

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

Sets text_direction.

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

Whether the text should break at soft line breaks.

If false, the glyphs in the text will be positioned as if there was unlimited horizontal space.

If the text exceeds the given number of lines, it will be truncated according to overflow and soft_wrap.

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

Sets soft_wrap.

pub fn overflow(self: RenderHandle<Self>, app: &App) -> TextOverflow

How visual overflow should be handled.

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

Sets overflow.

pub fn text_scaler(self: RenderHandle<Self>, app: &App) -> TextScaler

The font scaling strategy to use when laying out and rendering the text.

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

Sets text_scaler.

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

The pixel ratio of the device this paragraph is being rendered on.

Flutter repaints on change only on the web; here it is bookkeeping.

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

Sets device_pixel_ratio.

pub fn max_lines(self: RenderHandle<Self>, app: &App) -> Option<i32>

An optional maximum number of lines for the text to span, wrapping if necessary.

If the text exceeds the given number of lines, it will be truncated according to overflow and soft_wrap.

pub fn set_max_lines( self: RenderHandle<Self>, app: &mut App, value: Option<i32>, )

Sets max_lines. The value may be None. If it is not None, then it must be greater than zero.

pub fn text_width_basis(self: RenderHandle<Self>, app: &App) -> TextWidthBasis

Defines how to measure the width of the rendered text.

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

Sets text_width_basis.

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

Defines how to apply TextStyle.height over and under text.

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

Sets text_height_behavior.

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

The height of a space in text in logical pixels.

pub fn get_offset_for_caret( self: RenderHandle<Self>, app: &mut App, position: TextPosition, caret_prototype: Rect, ) -> Offset

Returns the offset at which to paint the caret.

Valid only after layout.

pub fn get_full_height_for_caret( self: RenderHandle<Self>, app: &mut App, position: TextPosition, ) -> f64

Returns the full height of the caret at the given position.

Valid only after layout.

pub fn get_boxes_for_selection( self: RenderHandle<Self>, app: &mut App, selection: TextSelection, box_height_style: BoxHeightStyle, box_width_style: BoxWidthStyle, ) -> Vec<TextBox>

Returns a list of rects that bound the given selection.

The box_height_style and box_width_style arguments may be used to select the shape of the TextBoxes. These properties default to BoxHeightStyle::Tight and BoxWidthStyle::Tight respectively.

A given selection might have more than one rect if this text painter contains bidirectional text because logically contiguous text might not be visually contiguous.

Valid only after layout.

pub fn get_position_for_offset( self: RenderHandle<Self>, app: &mut App, offset: Offset, ) -> TextPosition

Returns the position within the text for the given pixel offset.

Valid only after layout.

pub fn get_word_boundary( self: RenderHandle<Self>, app: &mut App, position: TextPosition, ) -> TextRange

Returns the text range of the word at the given offset. Characters not part of a word, such as spaces, symbols, and punctuation, have word breaks on both sides. In such cases, this method will return a text range that contains the given text position.

Word boundaries are defined more precisely in Unicode Standard Annex #29 http://www.unicode.org/reports/tr29/#Word_Boundaries.

Valid only after layout.

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

Returns the size of the text as laid out.

This can differ from size if the text overflowed or if the constraints provided by the parent RenderObject forced the layout to be bigger than necessary for the given text.

This returns the TextPainter::size of the underlying TextPainter.

Valid only after layout.

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

Whether the text was truncated or ellipsized as laid out.

This returns the TextPainter::did_exceed_max_lines of the underlying TextPainter.

Valid only after layout.

Trait Implementations

impl ContainerRenderObjectMixin for RenderParagraph

type ChildType = AnyRenderBox

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

type ParentDataType = TextParentData

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 RelayoutWhenSystemFontsChangeMixin for RenderParagraph

fn relayout_when_system_fonts_change_data( self: RenderHandle<Self>, app: &App, ) -> &RelayoutWhenSystemFontsChangeData

Mixin field access.

fn relayout_when_system_fonts_change_data_mut( self: RenderHandle<Self>, app: &mut App, ) -> &mut RelayoutWhenSystemFontsChangeData

See relayout_when_system_fonts_change_data.

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

A callback that is called when system fonts have changed.

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

Flutter’s attach override body after super.attach.

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

Flutter’s detach override body before super.detach.

fn system_fonts_listener(self: RenderHandle<Self>) -> Listener

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

impl RenderBox for RenderParagraph

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 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 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 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 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 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 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 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 RenderInlineChildrenContainerDefaults for RenderParagraph

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

Installs TextParentData on child, the mixin’s setupParentData.

fn layout_inline_children( self: RenderHandle<Self>, app: &mut App, max_width: f64, layout_child: ChildLayouter, get_child_baseline: ChildBaselineGetter, ) -> Vec<PlaceholderDimensions>

Computes the layout for every inline child using the max_width constraint.

fn position_inline_children( self: RenderHandle<Self>, app: &mut App, boxes: &[TextBox], )

Positions each inline child according to the coordinates provided in the boxes list.

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

Paints each inline child.

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

Performs a hit test on each inline child.

impl RenderObject for RenderParagraph

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 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 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 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.