Struct TreeView 

pub struct TreeView {
    pub nodes: Vec<TreeNode>,
    pub row_height: f64,
    pub indent_width: f64,
    pub font: Arc<Font>,
    pub font_size: f64,
    pub drag_enabled: bool,
    pub toggle_on_row_click: bool,
    /* private fields */
}

Fields

nodes: Vec<TreeNode>

row_height: f64

indent_width: f64

font: Arc<Font>

font_size: f64

drag_enabled: bool

toggle_on_row_click: bool

When true, clicking anywhere on a row that has children also toggles its expansion state. When false (the default), only the expand-toggle arrow collapses/expands; clicks elsewhere only select.

Set to true for file-explorer-style trees (the demo Tree tab). Leave false for the inspector tree, where clicking selects without accidentally collapsing an expanded branch.

Implementations

impl TreeView

pub fn new(font: Arc<Font>) -> Self

pub fn with_row_height(self, h: f64) -> Self

pub fn with_indent_width(self, w: f64) -> Self

pub fn with_font_size(self, s: f64) -> Self

pub fn with_drag_enabled(self) -> Self

pub fn with_toggle_on_row_click(self) -> Self

pub fn with_margin(self, m: Insets) -> Self

pub fn with_h_anchor(self, h: HAnchor) -> Self

pub fn with_v_anchor(self, v: VAnchor) -> Self

pub fn with_min_size(self, s: Size) -> Self

pub fn with_max_size(self, s: Size) -> Self

pub fn add_root(&mut self, label: impl Into<String>, icon: NodeIcon) -> usize

Add a root-level node; returns its index.

pub fn add_child( &mut self, parent_idx: usize, label: impl Into<String>, icon: NodeIcon, ) -> usize

Add a child of parent_idx; returns its index.

pub fn expand(&mut self, idx: usize)

Expand the node at idx.

impl TreeView

pub fn hovered_node_idx(&self) -> Option<usize>

Returns the node index currently under the cursor, or None.

Trait Implementations

impl Widget for TreeView

fn type_name(&self) -> &'static str

A static name for this widget type, used by the inspector. Default: “Widget”.

fn bounds(&self) -> Rect

Bounding rectangle in parent-local Y-up coordinates.

fn set_bounds(&mut self, b: Rect)

Set the bounding rectangle. Called by the parent during layout.

fn children(&self) -> &[Box<dyn Widget>]

Immutable access to child widgets.

fn children_mut(&mut self) -> &mut Vec<Box<dyn Widget>>

Mutable access to child widgets (required for event dispatch + layout).

fn is_focusable(&self) -> bool

Whether this widget can receive keyboard focus. Default: false.

fn margin(&self) -> Insets

Outer margin around this widget in logical units.

fn h_anchor(&self) -> HAnchor

Horizontal anchor: how this widget sizes/positions itself horizontally within the slot the parent assigns. Default: HAnchor::FIT (take natural content width).

fn v_anchor(&self) -> VAnchor

Vertical anchor: how this widget sizes/positions itself vertically within the slot the parent assigns. Default: VAnchor::FIT (take natural content height).

fn min_size(&self) -> Size

Minimum size constraint (logical units).

fn max_size(&self) -> Size

Maximum size constraint (logical units).

fn hit_test(&self, local_pos: Point) -> bool

Return true if local_pos (in this widget’s local coordinates) falls inside this widget’s interactive area. Default: axis-aligned rect test.

fn layout(&mut self, available: Size) -> Size

Compute desired size given available space, and update internal layout.

fn paint(&mut self, ctx: &mut dyn DrawCtx)

Paint this widget’s own content into ctx.

fn on_event(&mut self, event: &Event) -> EventResult

Handle an event. The event’s positions are already in local Y-up coordinates. Return EventResult::Consumed to stop bubbling.

fn claims_pointer_exclusively(&self, _local_pos: Point) -> bool

When true, hit_test_subtree stops recursing into this widget’s children and returns this widget as the hit target. Used for floating overlays (e.g. a scrollbar painted above its content) that must claim the pointer before children that happen to share the same pixels. Default: false.

fn id(&self) -> Option<&str>

Optional human-readable identifier for this widget instance.

fn is_visible(&self) -> bool

Return false to suppress painting this widget and all its children. The widget’s own paint() will not be called. Default: true.

fn properties(&self) -> Vec<(&'static str, String)>

Return type-specific properties for the inspector properties pane.

fn has_backbuffer(&self) -> bool

Whether this widget renders into its own offscreen buffer before compositing into the parent.

fn backbuffer_cache_mut(&mut self) -> Option<&mut BackbufferCache>

Opt into per-widget CPU bitmap caching with a dirty flag.

fn backbuffer_mode(&self) -> BackbufferMode

Storage format for this widget’s backbuffer. Ignored unless [backbuffer_cache_mut] returns Some. Default BackbufferMode::Rgba — correct for any widget. Opt into BackbufferMode::LcdCoverage only when the widget paints opaque content covering its full bounds.

fn contributes_children_to_inspector(&self) -> bool

Whether the inspector should recurse into this widget’s children.

fn show_in_inspector(&self) -> bool

Return false to hide this widget (and its subtree) from the inspector node snapshot entirely. Intended for zero-size utility widgets such as layout-time watchers / tickers / invisible composers — they bloat the inspector tree without providing user-relevant information and, at scale, can make the inspector’s per-frame tree rebuild expensive.

fn lcd_preference(&self) -> Option<bool>

Per-widget LCD subpixel preference for backbuffered text rendering.

fn paint_overlay(&mut self, _ctx: &mut dyn DrawCtx)

Paint decorations that must appear on top of all children.

fn clip_children_rect(&self) -> Option<(f64, f64, f64, f64)>

Return a clip rectangle (in local coordinates) that constrains all child painting. paint_subtree applies this clip before recursing into children, then restores the previous clip state afterward. The clip does not affect paint_overlay, which runs after the clip is removed.

fn enforce_integer_bounds(&self) -> bool

Whether paint_subtree should snap this widget’s incoming translation to the physical pixel grid.

fn take_raise_request(&mut self) -> bool

Container widgets (notably crate::widgets::Stack) call this on each child at the start of layout(). A widget that returns true is moved to the END of its parent’s child list — painted last, i.e. raised to the top of the z-order. take_ semantics: the call is also expected to clear the request so the child doesn’t keep getting raised every frame.

fn needs_paint(&self) -> bool

Return true if this widget, or any visible descendant, has state that requires a repaint (hover change, tween in flight, etc.).

fn next_paint_deadline(&self) -> Option<Instant>

Return the earliest wall-clock instant at which this widget (or any visible descendant) wants the next paint. None = no scheduled wake. The host loop turns a Some(t) into ControlFlow::WaitUntil(t) so e.g. a cursor blink fires without continuous polling.