Trait InstanceNode

pub trait InstanceNode {
    // Required methods
    fn base(&self) -> &BaseInstance;
    fn instantiate(args: InstantiationArgs) -> Rc<Self>
       where Self: Sized;
    fn resolve_debug(
        &self,
        f: &mut Formatter<'_>,
        expanded_node: Option<&ExpandedNode>,
    ) -> Result;

    // Provided methods
    fn update(
        self: Rc<Self>,
        _expanded_node: &Rc<ExpandedNode>,
        _context: &Rc<RuntimeContext>,
    ) { ... }
    fn handle_pre_render(
        &self,
        expanded_node: &ExpandedNode,
        context: &Rc<RuntimeContext>,
        rcs: &mut dyn RenderContext,
    ) { ... }
    fn render(
        &self,
        expanded_node: &ExpandedNode,
        context: &Rc<RuntimeContext>,
        rcs: &mut dyn RenderContext,
    ) { ... }
    fn handle_post_render(
        &self,
        expanded_node: &ExpandedNode,
        context: &Rc<RuntimeContext>,
        rcs: &mut dyn RenderContext,
    ) { ... }
    fn handle_mount(
        self: Rc<Self>,
        expanded_node: &Rc<ExpandedNode>,
        context: &Rc<RuntimeContext>,
    ) { ... }
    fn handle_unmount(
        &self,
        expanded_node: &Rc<ExpandedNode>,
        context: &Rc<RuntimeContext>,
    ) { ... }
    fn handle_scroll(&self, args_scroll: Scroll) { ... }
    fn get_template(&self) -> Option<&InstanceNodePtrList> { ... }
    fn clips_content(&self, _expanded_node: &ExpandedNode) -> bool { ... }
    fn handle_native_interrupt(
        &self,
        _expanded_node: &Rc<ExpandedNode>,
        _interrupt: &NativeInterrupt,
    ) { ... }
    fn handle_control_flow_node_expansion(
        self: Rc<Self>,
        _expanded_node: &Rc<ExpandedNode>,
        _context: &Rc<RuntimeContext>,
    ) { ... }
    fn handle_setup_slot_children(
        self: Rc<Self>,
        _expanded_node: &Rc<ExpandedNode>,
        _context: &Rc<RuntimeContext>,
    ) { ... }
}

Central runtime representation of a properties-computable and renderable node. InstanceNodes are conceptually stateless, and rely on ExpandedNodes for stateful representations.

An InstanceNode sits in between a [pax_compiler::TemplateNodeDefinition], the compile-time definition analogue to this instance, and ExpandedNode.

There is a 1:1 relationship between [pax_compiler::TemplateNodeDefinition]s and InstanceNodes. There is a one-to-many relationship between one InstanceNode and possibly many variant ExpandedNodes, due to duplication via for.

InstanceNodes are architecturally “type-aware” — they can perform type-specific operations e.g. on the state stored in ExpandedNode, while ExpandedNodes are “type-blind”. The latter store polymorphic data but cannot operate on it without the type-aware assistance of their linked InstanceNode.

(See [RepeatInstance#expand_node] where we visit a singular InstanceNode several times, producing multiple ExpandedNodes.)

Required Methods

fn base(&self) -> &BaseInstance

Retrieves the base instance, containing common functionality that all instances share

fn instantiate(args: InstantiationArgs) -> Rc<Self>

where Self: Sized,

fn resolve_debug( &self, f: &mut Formatter<'_>, expanded_node: Option<&ExpandedNode>, ) -> Result

Provided Methods

fn update( self: Rc<Self>, _expanded_node: &Rc<ExpandedNode>, _context: &Rc<RuntimeContext>, )

Updates the expanded node, recomputing its properties and possibly updating its children

fn handle_pre_render( &self, expanded_node: &ExpandedNode, context: &Rc<RuntimeContext>, rcs: &mut dyn RenderContext, )

Second lifecycle method during each render loop, occurs after properties have been computed, but before rendering Example use-case: perform side-effects to the drawing contexts. This is how [Frame] performs clipping, for example. Occurs in a pre-order traversal of the render tree.

fn render( &self, expanded_node: &ExpandedNode, context: &Rc<RuntimeContext>, rcs: &mut dyn RenderContext, )

Third lifecycle method during each render loop, occurs after all descendents have been rendered. Occurs in a post-order traversal of the render tree. Most primitives are expected to draw their contents to the rendering context during this event.

fn handle_post_render( &self, expanded_node: &ExpandedNode, context: &Rc<RuntimeContext>, rcs: &mut dyn RenderContext, )

Fourth and final lifecycle method during each render loop, occurs after all descendents have been rendered AND the current node has been rendered. Useful for clean-up, e.g. this is where Frame cleans up the drawing contexts to stop clipping. Occurs in a post-order traversal of the render tree.

fn handle_mount( self: Rc<Self>, expanded_node: &Rc<ExpandedNode>, context: &Rc<RuntimeContext>, )

Fires during the tick when a node is first attached to the render tree. For example, this event fires by all nodes on the global first tick, and by all nodes in a subtree when a Conditional subsequently turns on a subtree (i.e. when the Conditionals criterion becomes true after being false through the end of at least 1 frame.) A use-case: send a message to native renderers that a Text element should be rendered and tracked

fn handle_unmount( &self, expanded_node: &Rc<ExpandedNode>, context: &Rc<RuntimeContext>, )

Fires during element unmount, when an element is about to be removed from the render tree (e.g. by a Conditional) A use-case: send a message to native renderers that a Text element should be removed

fn handle_scroll(&self, args_scroll: Scroll)

Invoked by event interrupts to pass scroll information to render node

fn get_template(&self) -> Option<&InstanceNodePtrList>

fn clips_content(&self, _expanded_node: &ExpandedNode) -> bool

Used by frame to control content clipping

fn handle_native_interrupt( &self, _expanded_node: &Rc<ExpandedNode>, _interrupt: &NativeInterrupt, )

fn handle_control_flow_node_expansion( self: Rc<Self>, _expanded_node: &Rc<ExpandedNode>, _context: &Rc<RuntimeContext>, )

fn handle_setup_slot_children( self: Rc<Self>, _expanded_node: &Rc<ExpandedNode>, _context: &Rc<RuntimeContext>, )

Trait Implementations

impl Debug for dyn InstanceNode

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

Implementors

impl InstanceNode for ComponentInstance

impl InstanceNode for ConditionalInstance

impl InstanceNode for RepeatInstance

impl InstanceNode for SlotInstance