Module callbacks 

Callback handling for layout events (invocation, result processing). Callback handling for layout events

This module provides the CallbackInfo struct and related types for handling UI callbacks. Callbacks need access to layout information (node sizes, positions, hierarchy), which is why this module lives in azul-layout instead of azul-core.

Structs

Callback

Stores a function pointer that is executed when the given UI element is hit

CallbackInfo

CallbackInfo is a lightweight wrapper around pointers to stack-local data.

CallbackInfoRefData

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

DeleteResult

FFI-safe wrapper for delete inspection result (range_to_delete, deleted_text)

ExternalSystemCallbacks

Config necessary for threading + animations to work in no_std environments

MenuCallback

Menu callback: What data / function pointer should be called when the menu item is clicked?

PenTilt

FFI-safe wrapper for pen tilt angles (x_tilt, y_tilt) in degrees

RenderImageCallback

Callback that returns a rendered OpenGL texture

RenderImageCallbackInfo

Information passed to image rendering callbacks

SelectAllResult

FFI-safe wrapper for select-all result (full_text, selected_range)

Enums

CallbackChange

Represents a change made by a callback that will be applied after the callback returns

FocusUpdateRequest

Request to change focus, returned from callbacks

OptionCallback

FFI-safe Option type for C interop.

OptionDeleteResult

OptionMenuCallback

Optional MenuCallback

OptionPenTilt

OptionSelectAllResult

ResultStringString

Result type for functions returning String or a String error

ResultU8VecString

Result type for functions returning U8Vec or a String error

ResultVoidString

Result type for functions returning () or a String error

Statics

CALLBACK_INVOKER

Process-global slot for this callback kind’s host-side invoker.

Functions

AzApp_setCallbackInvoker

Register the host-side invoker for this callback kind.

AzCallback_createFromHostHandle

C-ABI export wrapping <Wrapper>::create_from_host_handle.

base64_encode

Encode bytes to Base64 string

css_properties_need_relayout

Whether a batch of CSS property overrides can move geometry, i.e. whether applying it has to re-run layout or only has to repaint.

Type Aliases

AzCallbackInvoker

Pointer-arg variant of this callback kind’s typedef.

CallbackType

Main callback type for UI event handling

RenderImageCallbackType

Callback type that renders an OpenGL texture