Struct Modifier 

pub struct Modifier {

    pub key: Option<u64>,
    pub size: Option<Size>,
    pub width: Option<f32>,
    pub height: Option<f32>,
    pub fill_max: bool,
    pub fill_max_w: bool,
    pub fill_max_h: bool,
    pub padding: Option<f32>,
    pub padding_values: Option<PaddingValues>,
    pub min_width: Option<f32>,
    pub min_height: Option<f32>,
    pub max_width: Option<f32>,
    pub max_height: Option<f32>,
    pub background: Option<Brush>,
    pub state_colors: Option<StateColors>,
    pub state_elevation: Option<StateElevation>,
    pub border: Option<Border>,
    pub flex_grow: Option<f32>,
    pub flex_shrink: Option<f32>,
    pub flex_basis: Option<f32>,
    pub flex_wrap: Option<FlexWrap>,
    pub flex_dir: Option<FlexDirection>,
    pub gap: Option<f32>,
    pub row_gap: Option<f32>,
    pub column_gap: Option<f32>,
    pub align_self: Option<AlignSelf>,
    pub justify_content: Option<JustifyContent>,
    pub align_items_container: Option<AlignItems>,
    pub align_content: Option<AlignContent>,
    pub clip_rounded: Option<f32>,
    pub z_index: f32,
    pub render_z_index: Option<f32>,
    pub hit_passthrough: bool,
    pub input_blocker: bool,
    pub repaint_boundary: bool,
    pub click: bool,
    pub disabled: bool,
    pub on_scroll: Option<Rc<dyn Fn(Vec2) -> Vec2>>,
    pub on_pointer_down: Option<Rc<dyn Fn(PointerEvent)>>,
    pub on_pointer_move: Option<Rc<dyn Fn(PointerEvent)>>,
    pub on_pointer_up: Option<Rc<dyn Fn(PointerEvent)>>,
    pub on_pointer_enter: Option<Rc<dyn Fn(PointerEvent)>>,
    pub on_pointer_leave: Option<Rc<dyn Fn(PointerEvent)>>,
    pub semantics: Option<Semantics>,
    pub alpha: Option<f32>,
    pub graphics_layer: Option<f32>,
    pub shadow: Option<ShadowSpec>,
    pub transform: Option<Transform>,
    pub grid: Option<GridConfig>,
    pub grid_col_span: Option<u16>,
    pub grid_row_span: Option<u16>,
    pub position_type: Option<PositionType>,
    pub offset_left: Option<f32>,
    pub offset_right: Option<f32>,
    pub offset_top: Option<f32>,
    pub offset_bottom: Option<f32>,
    pub margin_left: Option<f32>,
    pub margin_right: Option<f32>,
    pub margin_top: Option<f32>,
    pub margin_bottom: Option<f32>,
    pub aspect_ratio: Option<f32>,
    pub painter: Option<Rc<dyn Fn(&mut Scene, Rect)>>,
    pub on_drag_start: Option<Rc<dyn Fn(DragStart) -> Option<DragPayload>>>,
    pub on_drag_end: Option<Rc<dyn Fn(DragEnd)>>,
    pub on_drag_enter: Option<Rc<dyn Fn(DragOver)>>,
    pub on_drag_over: Option<Rc<dyn Fn(DragOver)>>,
    pub on_drag_leave: Option<Rc<dyn Fn(DragOver)>>,
    pub on_drop: Option<Rc<dyn Fn(DropEvent) -> bool>>,
    pub on_action: Option<Rc<dyn Fn(Action) -> bool>>,
    pub cursor: Option<CursorIcon>,
    pub animate_content_size: Option<AnimationSpec>,
    pub focus_requester: Option<FocusRequester>,
    pub on_focus_changed: Option<Rc<dyn Fn(bool)>>,
}

Fields

key: Option<u64>

Optional stable identity key for this view node.

If set, layout_and_paint will prefer this over child index when assigning stable ViewIds. This is the “escape hatch” for dynamic lists / conditional UI where index-based identity would otherwise shift.

size: Option<Size>

width: Option<f32>

height: Option<f32>

fill_max: bool

fill_max_w: bool

fill_max_h: bool

padding: Option<f32>

padding_values: Option<PaddingValues>

min_width: Option<f32>

min_height: Option<f32>

max_width: Option<f32>

max_height: Option<f32>

background: Option<Brush>

state_colors: Option<StateColors>

state_elevation: Option<StateElevation>

border: Option<Border>

flex_grow: Option<f32>

flex_shrink: Option<f32>

flex_basis: Option<f32>

flex_wrap: Option<FlexWrap>

flex_dir: Option<FlexDirection>

gap: Option<f32>

row_gap: Option<f32>

column_gap: Option<f32>

align_self: Option<AlignSelf>

justify_content: Option<JustifyContent>

align_items_container: Option<AlignItems>

align_content: Option<AlignContent>

clip_rounded: Option<f32>

z_index: f32

Z-index for hit-testing order (higher = receives events first).

render_z_index: Option<f32>

Z-index for render order (higher = painted on top). If None, uses tree order.

hit_passthrough: bool

If true, this view does not create hit regions.

input_blocker: bool

If true, this view blocks pointer/touch input for hits below it.

repaint_boundary: bool

click: bool

disabled: bool

When true, the component ignores pointer events and appears disabled.

on_scroll: Option<Rc<dyn Fn(Vec2) -> Vec2>>

on_pointer_down: Option<Rc<dyn Fn(PointerEvent)>>

on_pointer_move: Option<Rc<dyn Fn(PointerEvent)>>

on_pointer_up: Option<Rc<dyn Fn(PointerEvent)>>

on_pointer_enter: Option<Rc<dyn Fn(PointerEvent)>>

on_pointer_leave: Option<Rc<dyn Fn(PointerEvent)>>

semantics: Option<Semantics>

alpha: Option<f32>

graphics_layer: Option<f32>

shadow: Option<ShadowSpec>

transform: Option<Transform>

grid: Option<GridConfig>

grid_col_span: Option<u16>

grid_row_span: Option<u16>

position_type: Option<PositionType>

offset_left: Option<f32>

offset_right: Option<f32>

offset_top: Option<f32>

offset_bottom: Option<f32>

margin_left: Option<f32>

margin_right: Option<f32>

margin_top: Option<f32>

margin_bottom: Option<f32>

aspect_ratio: Option<f32>

painter: Option<Rc<dyn Fn(&mut Scene, Rect)>>

on_drag_start: Option<Rc<dyn Fn(DragStart) -> Option<DragPayload>>>

on_drag_end: Option<Rc<dyn Fn(DragEnd)>>

on_drag_enter: Option<Rc<dyn Fn(DragOver)>>

on_drag_over: Option<Rc<dyn Fn(DragOver)>>

on_drag_leave: Option<Rc<dyn Fn(DragOver)>>

on_drop: Option<Rc<dyn Fn(DropEvent) -> bool>>

on_action: Option<Rc<dyn Fn(Action) -> bool>>

cursor: Option<CursorIcon>

Cursor icon hint for desktop/web runners.

animate_content_size: Option<AnimationSpec>

If set, the size of this node will smoothly animate to its target size whenever content size changes. Uses the provided animation spec.

focus_requester: Option<FocusRequester>

A FocusRequester handle that will be associated with this view. When the requester’s request_focus() is called, keyboard focus will move to this view.

on_focus_changed: Option<Rc<dyn Fn(bool)>>

Called when this view gains or loses focus. The boolean parameter is true when focused, false when unfocused.

Implementations

impl Modifier

pub fn then(self, other: Self) -> Self

Chain another modifier’s settings onto this one. Useful for creating reusable modifier templates.

impl Modifier

pub fn new() -> Self

pub fn key(self, key: u64) -> Self

Attaches a stable identity key to this view node. Use for dynamic lists / conditional UI where index-based identity can shift.

pub fn size(self, w: f32, h: f32) -> Self

pub fn width(self, w: f32) -> Self

pub fn height(self, h: f32) -> Self

pub fn fill_max_size(self) -> Self

pub fn fill_max_width(self) -> Self

pub fn fill_max_height(self) -> Self

pub fn padding(self, v: f32) -> Self

pub fn padding_values(self, padding: PaddingValues) -> Self

pub fn ime_padding(self) -> Self

Add padding equal to the current IME (soft keyboard) bottom inset. Combine with system_bars_padding() to handle both system bars and keyboard.

pub fn system_bars_padding(self) -> Self

Add padding equal to the current system bar insets (status bar top, nav bar bottom).

pub fn status_bars_padding(self) -> Self

Add status bar inset as top padding.

pub fn navigation_bars_padding(self) -> Self

Add navigation bar inset as bottom padding.

pub fn min_size(self, w: f32, h: f32) -> Self

pub fn max_size(self, w: f32, h: f32) -> Self

pub fn min_width(self, w: f32) -> Self

pub fn min_height(self, h: f32) -> Self

pub fn max_width(self, w: f32) -> Self

pub fn max_height(self, h: f32) -> Self

pub fn background(self, color: Color) -> Self

Set a solid color background.

pub fn background_brush(self, brush: Brush) -> Self

Set a brush (solid, gradient, etc.) background.

pub fn border(self, width: f32, color: Color, radius: f32) -> Self

pub fn flex_grow(self, v: f32) -> Self

pub fn flex_shrink(self, v: f32) -> Self

pub fn flex_basis(self, v: f32) -> Self

pub fn flex_wrap(self, w: FlexWrap) -> Self

pub fn flex_dir(self, d: FlexDirection) -> Self

pub fn gap(self, v: f32) -> Self

pub fn row_gap(self, v: f32) -> Self

pub fn column_gap(self, v: f32) -> Self

pub fn align_self(self, a: AlignSelf) -> Self

pub fn align_self_center(self) -> Self

pub fn justify_content(self, j: JustifyContent) -> Self

pub fn align_items(self, a: AlignItems) -> Self

pub fn align_content(self, a: AlignContent) -> Self

pub fn clip_rounded(self, radius: f32) -> Self

pub fn z_index(self, z: f32) -> Self

pub fn render_z_index(self, z: f32) -> Self

Sets the render z-index for this view. Higher values are painted on top. Unlike z_index (which only affects hit-testing), this affects visual layering.

pub fn input_blocker(self) -> Self

Prevent pointer/touch from reaching lower layers.

pub fn hit_passthrough(self) -> Self

pub fn clickable(self) -> Self

pub fn state_colors(self, colors: StateColors) -> Self

Set state-driven background colors for hover, press, disabled states. The layout engine automatically selects and animates between these based on interaction.

pub fn state_elevation(self, elev: StateElevation) -> Self

Set state-driven elevation values for hover, press, disabled states.

pub fn disabled(self) -> Self

Mark this component as disabled - it won’t respond to pointer events.

pub fn enabled(self, enabled: bool) -> Self

Mark this component as enabled or disabled.

pub fn on_scroll(self, f: impl Fn(Vec2) -> Vec2 + 'static) -> Self

pub fn on_pointer_down(self, f: impl Fn(PointerEvent) + 'static) -> Self

pub fn on_pointer_move(self, f: impl Fn(PointerEvent) + 'static) -> Self

pub fn on_pointer_up(self, f: impl Fn(PointerEvent) + 'static) -> Self

pub fn on_pointer_enter(self, f: impl Fn(PointerEvent) + 'static) -> Self

pub fn on_pointer_leave(self, f: impl Fn(PointerEvent) + 'static) -> Self

pub fn semantics(self, s: Semantics) -> Self

pub fn alpha(self, a: f32) -> Self

pub fn graphics_layer(self, alpha: f32) -> Self

Render this subtree into an offscreen texture, then composite it back into the parent with the given group alpha (0.0..=1.0). Allows correct blending when children overlap inside the layer, and sets up the architecture for future layer effects (shadow, blur, clip).

pub fn shadow(self, blur_radius: f32, offset_y: f32) -> Self

Drop shadow with the given blur_radius (dp) and vertical offset_y (dp). The shadow color defaults to black with alpha 64 (~25%). Combines with Modifier::graphics_layer to draw a shadow underneath the layer.

pub fn shadow_with_color( self, blur_radius: f32, offset_y: f32, color: Color, ) -> Self

Drop shadow with a custom color. Alpha 0..=255.

pub fn elevation(self, level: f32) -> Self

Material-style elevation. Auto-scales blur and offset by level (dp) and uses a default shadow color. Level 0 = no shadow; 4 = subtle; 16 = strong. Requires Modifier::graphics_layer to take effect.

pub fn transform(self, t: Transform) -> Self

pub fn grid(self, columns: usize, row_gap: f32, column_gap: f32) -> Self

pub fn grid_span(self, col_span: u16, row_span: u16) -> Self

pub fn absolute(self) -> Self

pub fn offset( self, left: Option<f32>, top: Option<f32>, right: Option<f32>, bottom: Option<f32>, ) -> Self

pub fn offset_left(self, v: f32) -> Self

pub fn offset_right(self, v: f32) -> Self

pub fn offset_top(self, v: f32) -> Self

pub fn offset_bottom(self, v: f32) -> Self

pub fn margin(self, v: f32) -> Self

pub fn margin_horizontal(self, v: f32) -> Self

pub fn margin_vertical(self, v: f32) -> Self

pub fn aspect_ratio(self, ratio: f32) -> Self

pub fn painter(self, f: impl Fn(&mut Scene, Rect) + 'static) -> Self

pub fn scale(self, s: f32) -> Self

pub fn scale2(self, sx: f32, sy: f32) -> Self

pub fn translate(self, x: f32, y: f32) -> Self

pub fn translate_vec2(self, v: Vec2) -> Self

pub fn rotate(self, radians: f32) -> Self

pub fn weight(self, w: f32) -> Self

pub fn repaint_boundary(self) -> Self

Marks this view as a repaint boundary candidate.

The engine may cache its painted output.

pub fn on_action(self, f: impl Fn(Action) -> bool + 'static) -> Self

pub fn on_drag_start( self, f: impl Fn(DragStart) -> Option<DragPayload> + 'static, ) -> Self

Mark this node as a drag source. Return Some(payload) to start dragging.

pub fn on_drag_end(self, f: impl Fn(DragEnd) + 'static) -> Self

Called when a drag ends (drop accepted or canceled/ignored).

pub fn on_drag_enter(self, f: impl Fn(DragOver) + 'static) -> Self

Called when a drag first enters this target.

pub fn on_drag_over(self, f: impl Fn(DragOver) + 'static) -> Self

Called on every pointer move while a drag is over this target.

pub fn on_drag_leave(self, f: impl Fn(DragOver) + 'static) -> Self

Called when a drag leaves this target.

pub fn on_drop(self, f: impl Fn(DropEvent) -> bool + 'static) -> Self

Called on pointer release while a drag is over this target. Return true to accept the drop.

pub fn cursor(self, c: CursorIcon) -> Self

Set the cursor icon hint for desktop/web runners.

pub fn animate_content_size(self, spec: AnimationSpec) -> Self

Animate size changes smoothly when the content’s natural size changes. Uses the provided AnimationSpec for the transition. The content will be clipped to the animated size during transitions.

pub fn focus_requester(self, fr: FocusRequester) -> Self

Attach a FocusRequester to this view. The requester will be associated with the view’s focusable element, allowing programmatic focus requests.

pub fn on_focus_changed(self, f: impl Fn(bool) + 'static) -> Self

Register a callback that fires when this view gains or loses keyboard focus. The argument is true when the view receives focus, false when it loses it.

Trait Implementations

impl Clone for Modifier

fn clone(&self) -> Modifier

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Modifier

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

Formats the value using the given formatter.

impl Default for Modifier

fn default() -> Modifier

Returns the “default value” for a type.