Struct VisualChanged 

pub struct VisualChanged {
    pub new_visual_aabb: Rect,
    pub new_world_transform: Affine,
}

Event fired when a view’s visual representation in the window changes.

This is fired when the view’s final rendered position or transform changes, including changes from CSS-like transforms (translation, scale, rotation). This represents the view’s actual visual appearance in the window after all transforms have been applied.

Important: Visual vs Layout Coordinates

Use this event when you need to know where the view actually appears on screen. The coordinates and transform provided here reflect the final rendered state after all transforms (translation, scale, rotation) from this view and all ancestors have been applied.

When to use VisualChanged vs LayoutChanged

• Use VisualChanged: When you need the actual rendered position on screen, or to position elements relative to where a view visually appears (e.g., tooltips, popovers, overlays)
• Use LayoutChanged: When you only care about layout box sizes or relative positioning within the layout tree, ignoring transforms

Coordinate Spaces in Floem

Note: All event handling and painting in Floem happen in the view’s local coordinate space. Floem automatically handles transformations to and from local coordinates. You typically only need visual window coordinates when positioning separate elements (like overlays or platform windows) relative to a view’s visual appearance, or when interacting with platform APIs that expect window coordinates.

Use Cases for VisualChanged

• Positioning tooltips or popovers relative to a transformed view
• Implementing drag-and-drop with visual feedback
• Coordinating with platform overlays or native windows
• Calculating whether two views visually overlap on screen

Fields

new_visual_aabb: Rect

The new axis-aligned bounding box in window coordinates after all transforms

This is the smallest rectangle that contains the view after all transforms are applied. For rotated views, this will be larger than the view’s layout box.

new_world_transform: Affine

The new world transform matrix combining all parent and local transforms

This transform maps from the view’s local coordinate space to window coordinates.

Implementations

impl VisualChanged

pub fn listener() -> VisualChangedListener

Get the event listener for this custom event

pub fn extract(event: &Event) -> Option<&VisualChanged>

Attempt to extract this event type from a generic [Event].

Equivalent to: Self::listener_key().extract(event)

impl VisualChanged

pub fn visual_window_origin(&self) -> Point

Get the visual origin of the view in window coordinates

This returns the top-left corner of the visual bounding box after all transforms. Note that for rotated or scaled views, this may not correspond directly to the layout box origin transformed by new_world_transform.

pub fn local_to_window(&self, local_point: Point) -> Point

Transform a point from the view’s local coordinate space to window coordinates

This applies the full world transform to convert a point in the view’s local coordinate space to its position in the window.

pub fn window_to_local(&self, window_point: Point) -> Point

Transform a point from window coordinates to the view’s local coordinate space

This applies the inverse world transform to convert a point in window coordinates to the view’s local coordinate space. Returns None if the transform is not invertible.

Trait Implementations

impl Clone for VisualChanged

fn clone(&self) -> VisualChanged

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for VisualChanged

impl CustomEvent for VisualChanged

fn listener_key() -> EventListenerKey

Get the unique key for this event type

fn listener_key_dyn(&self) -> EventListenerKey

Get the listener key for this trait object

fn allow_disabled(&self) -> bool

fn as_any(&self) -> &dyn Any

Downcast helper

fn clone_box(&self) -> Box<dyn CustomEvent>

Clone this event into a Box without requiring Clone on the trait

fn transform(&mut self, transform: Affine)

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

Format for Debug output. Default uses the type name.

impl Debug for VisualChanged

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

Formats the value using the given formatter.

impl PartialEq for VisualChanged

fn eq(&self, other: &VisualChanged) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for VisualChanged