Struct Callback 

pub struct Callback { /* private fields */ }

A generic callback handler for executing functions with stored arguments. Callback allows you to associate a function with an optional argument and invoke it later.

Usage

Callback is use for creating a Option component. The callback will be trigger when the Option component is selected.

Implementations

impl Callback

pub fn new<T>(func: fn(&Option<Box<dyn Any>>) -> FtuiResult<()>, arg: T) -> Self

where T: 'static,

Constructs a new Callback with an associated argument.

Parameters

• func: A callback function created using the cbk_new_callback_func! macro.
• arg: The argument value to associate with the Callback (T: 'static).

Example

// Define a callback function using the macro.
cbk_new_callback_func!(callback_function, arg, {
    ...
});

// Create a `Callback` with an associated `u32` value.
let _ = Callback::new(callback_function, 5u32);

pub fn no_arg(func: fn(&Option<Box<dyn Any>>) -> FtuiResult<()>) -> Self

Constructs a new Callback without an associated argument.

Parameters

• func: A callback function created using the cbk_new_callback_func! macro.

Example

// Define a callback function using the macro.
cbk_new_callback_func!(callback_function, arg, {
    ...
});

// Create a `Callback` without a associated argument.
let _ = Callback::no_arg(callback_function);

pub fn call(&self) -> FtuiResult<()>

Invoke the Callback. Typically used for testing purposes.

Returns

• Ok(()): Returns nothing.
• Err(FtuiError): Returns an error.

Example

// Define a callback function that accepts a `u32` and prints it.
cbk_new_callback_func!(print_num, arg, {
    println!("{}", tui::cbk::cast_arg::<u32>(arg)?);
    Ok(())
});
 
// Create a `Callback` with an argument of 5 and invoke it.
Callback::new(print_num, 5u32).call()?; // Prints: 5

pub fn update_arg<T>(&mut self, arg: T)

where T: 'static,

Updates the argument associated with this Callback.

Parameters

• arg: The new argument value to associate with the Callback (T' static).

Example

// Define a callback function that accepts a `u32` and prints it.
cbk_new_callback_func!(print_num, arg, {
    println!("{}", tui::cbk::cast_arg::<u32>(arg)?);
    Ok(())
});
 
// Create a `Callback` with an initial argument.
let mut callback = Callback::new(print_num, 5u32); 

callback.call()?; // Prints: 5

// Update the argument to a new value.
callback.update_arg(6u32);

callback.call()?; // Prints: 6

pub fn remove_arg(&mut self)

Remove the argument associated with the Callback.