The type for renderer callbacks inherited by all nodes in a tree.

create_root ctx () is a new root node backed by ctx's layout tree.

Optional parameters:

• id: identifier string. Defaults to "node-N".
• style: flexbox style. Defaults to Toffee.Style.default.
• glyph_pool: glyph pool for text rendering. Defaults to none.

num t is t's numeric identifier, unique within the renderer.

toffee_node t is t's layout node identifier.

set_is_root t v marks or unmarks t as a root node.

layout_dirty t is true iff t needs re-layout.

clear_layout_dirty t clears t's layout dirty flag.

update_layout t ~x ~y ~width ~height caches layout results for t, enabling O(1) queries via x, y, width, and height.

measure t is t's measure function, if any.

pre_render_update t ~delta runs t's on-frame and resize hooks.

render t grid ~delta invokes t's render callback.

render_before t is t's pre-render hook, if any.

render_after t is t's post-render hook, if any.

ensure_frame_buffer t ~parent is Some buf if t uses buffered rendering and has positive dimensions, None otherwise.

blit_frame_buffer t ~dst copies t's frame buffer into dst.

render_full t ~grid ~delta runs the complete render sequence for t: frame buffer selection, pre-render hook, render callback, post-render hook, and frame buffer blit.

children_z t is t's children sorted by z-index. The result is cached.

iter_children_z t f applies f to each child of t in z-index order.

children_in_viewport ~parent ~viewport ~padding is the children of parent whose bounds intersect viewport expanded by padding cells, sorted by z-index.

focus_direct t focuses t without delegating to the renderer. Returns false if t is not focusable.

blur_direct t blurs t without delegating to the renderer.

live_count t is the total number of live-rendering nodes in t's subtree, including t itself.

set_on_live_count_change t cb registers an observer called when live_count t changes. None clears it.

set_lifecycle_pass t callback registers a lifecycle pass hook for t. None clears it.

run_lifecycle_pass t invokes t's lifecycle callback, if any.

emit_mouse t event dispatches event to t's mouse handlers, bubbling to ancestors unless propagation is stopped via Event.Mouse.stop_propagation.

emit_key t event dispatches event to t's key handlers.

emit_default_key t event dispatches event to t's default key handler, if any.

emit_paste t event dispatches event to t's paste handler, if any.

emit_selection_changed t sel notifies t's selection on_change callback with sel. Returns false if no callback is registered.

clear_selection t calls t's selection clear callback, if any.

should_start_selection t ~x ~y is true iff t's should_start callback returns true for (x, y). Returns false if no callback is registered.

get_selected_text t calls t's get_text callback and returns the result, or "" if no callback is registered.

child_clip t is the clipping rectangle for t's children as returned by t's clip override, or None if no override is set.

set_glyph_pool t pool assigns a glyph pool for text rendering by t and its descendants.

glyph_pool t is t's glyph pool, or None if none is assigned.