Struct CallbackInfoRefData 

pub struct CallbackInfoRefData<'a> {
    pub layout_window: &'a LayoutWindow,
    pub renderer_resources: &'a RendererResources,
    pub previous_window_state: &'a Option<FullWindowState>,
    pub current_window_state: &'a FullWindowState,
    pub gl_context: &'a OptionGlContextPtr,
    pub current_scroll_manager: &'a BTreeMap<DomId, BTreeMap<NodeHierarchyItemId, ScrollPosition>>,
    pub current_window_handle: &'a RawWindowHandle,
    pub system_callbacks: &'a ExternalSystemCallbacks,
    pub system_style: Arc<SystemStyle>,
    pub monitors: Arc<Mutex<MonitorVec>>,
    pub ctx: OptionRefAny,
}

Reference data container for CallbackInfo (all read-only fields)

This struct consolidates all readonly references that callbacks need to query window state. By grouping these into a single struct, we reduce the number of parameters to CallbackInfo::new() from 13 to 3, making the API more maintainable and easier to extend.

This is pure syntax sugar - the struct lives on the stack in the caller and is passed by reference.

Fields

layout_window: &'a LayoutWindow

Pointer to the LayoutWindow containing all layout results (READ-ONLY for queries)

renderer_resources: &'a RendererResources

Necessary to query FontRefs from callbacks

previous_window_state: &'a Option<FullWindowState>

Previous window state (for detecting changes)

current_window_state: &'a FullWindowState

State of the current window that the callback was called on (read only!)

gl_context: &'a OptionGlContextPtr

An Rc to the OpenGL context, in order to be able to render to OpenGL textures

current_scroll_manager: &'a BTreeMap<DomId, BTreeMap<NodeHierarchyItemId, ScrollPosition>>

Immutable reference to where the nodes are currently scrolled (current position)

current_window_handle: &'a RawWindowHandle

Handle of the current window

system_callbacks: &'a ExternalSystemCallbacks

Callbacks for creating threads and getting the system time (since this crate uses no_std)

system_style: Arc<SystemStyle>

Platform-specific system style (colors, spacing, etc.) Arc allows safe cloning in callbacks without unsafe pointer manipulation

monitors: Arc<Mutex<MonitorVec>>

Shared monitor list - initialized once at app start, updated by the platform layer on monitor topology changes (e.g. WM_DISPLAYCHANGE, NSScreenParametersChanged). Callbacks lock the mutex to read; platform locks to write.

ctx: OptionRefAny

The callable for FFI language bindings (Python, etc.) Cloned from the Callback struct before invocation. Native Rust callbacks have this as None.

Trait Implementations

impl<'a> Debug for CallbackInfoRefData<'a>

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

Formats the value using the given formatter.