Struct zng_app::widget::node::NilUiNode

pub struct NilUiNode;

A UI node that does nothing and has collapsed layout (zero size).

Trait Implementations

impl UiNode for NilUiNode

fn measure(&mut self, _: &mut WidgetMeasure) -> PxSize

Computes the widget size given the contextual layout metrics without actually updating the widget layout.

fn layout(&mut self, _: &mut WidgetLayout) -> PxSize

Computes the widget layout given the contextual layout metrics.

fn is_nil(&self) -> bool

Gets if this node does nothing and is layout collapsed.

fn info(&mut self, info: &mut WidgetInfoBuilder)

Builds widget info.

fn init(&mut self)

Initializes the node in a new UI context.

fn deinit(&mut self)

Deinitializes the node in the current UI context.

fn update(&mut self, updates: &WidgetUpdates)

Receives variable and other non-event updates.

fn event(&mut self, update: &EventUpdate)

Receives an event.

fn render(&mut self, frame: &mut FrameBuilder)

Generates render instructions and updates transforms and hit-test areas.

fn render_update(&mut self, update: &mut FrameUpdate)

Updates values in the last generated frame.

fn boxed(self) -> BoxedUiNode

where Self: Sized,

Box this node or just returns self if it is already a BoxedUiNode.

fn cfg_boxed(self) -> BoxedUiNode

where Self: Sized,

Helper for complying with the "dyn_node" feature, boxes the node or just returns it depending of the compile time feature.

fn is_widget(&self) -> bool

Gets if this node represents a full widget, that is, it is the outer-most widget node and defines a widget context.

fn with_context<R, F>( &mut self, update_mode: WidgetUpdateMode, f: F ) -> Option<R>

where F: FnOnce() -> R,

Calls f with the WIDGET context of the node if it is_widget.

fn into_widget(self) -> BoxedUiNode

where Self: Sized,

Gets a BoxedUiNode that is a full widget.

fn init_widget(self) -> (BoxedUiNode, ResponseVar<WidgetId>)

where Self: Sized,

Gets a BoxedUiNode that already is a full widget or will be after init and a response var that already is the widget ID or will update once after init with the ID.

fn downcast_unbox<T: UiNode>(self) -> Result<T, BoxedUiNode>

where Self: Sized,

Downcast to T, if self is T or self is a BoxedUiNode that is T.

fn actual_type_id(&self) -> TypeId

Returns the type_id of the unboxed node.

fn as_any(&self) -> &dyn Any

where Self: Sized,

Access to dyn Any methods.

fn as_any_mut(&mut self) -> &mut dyn Any

where Self: Sized,

Access to mut dyn Any methods.

fn trace<E, S>(self, enter_mtd: E) -> BoxedUiNode

where Self: Sized, E: FnMut(UiNodeOpMethod) -> S + Send + 'static,

Wraps the node in a node that, before delegating each method, calls a closure with the UiNodeOpMethod, the closure can return a span that is dropped after the method delegation.

fn op(&mut self, op: UiNodeOp<'_>)

Runs the UiNodeOp.