Trait Component 

pub trait Component: ComponentAccessor + Downcast {
    // Required method
    fn draw(&mut self, f: &mut Frame<'_>, area: Rect);

    // Provided methods
    fn init(&mut self, area: Rect) { ... }
    fn keybindings(&self) -> KeyBindings { ... }
    fn handle_key_events(&mut self, key: KeyEvent) -> Option<Action> { ... }
    fn handle_mouse_events(&mut self, mouse: MouseEvent) -> Option<Action> { ... }
    fn handle_tick_event(&mut self) -> Option<Action> { ... }
    fn handle_frame_event(&mut self) -> Option<Action> { ... }
    fn handle_paste_event(&mut self, message: &str) -> Option<Action> { ... }
    fn update(&mut self, action: &Action) { ... }
    fn on_event(&mut self, message: &str) { ... }
    fn child_mut(&mut self, name: &str) -> Option<&mut Box<dyn Component>> { ... }
    fn child(&mut self, name: &str) -> Option<&Box<dyn Component>> { ... }
    fn on_active_changed(&mut self, active: bool) { ... }
}

The main trait for all UI components in the weavetui framework.

This trait defines the core functionality of a component, including event handling (handle_key_events, handle_mouse_events, etc.) and rendering (draw).

Implementors must also implement ComponentAccessor and Downcast.

Required Methods

fn draw(&mut self, f: &mut Frame<'_>, area: Rect)

Render the component on the screen. (REQUIRED)

Arguments

• f - A frame used for rendering.
• area - The area in which the component should be drawn.

Provided Methods

fn init(&mut self, area: Rect)

Initialize the component with a specified area if necessary. Usefull for components that need to performe some initialization before the first render.

Arguments

• area - Rectangular area where the component will be rendered the first time.

fn keybindings(&self) -> KeyBindings

Returns the KeyBindings for this component.

KeyBindings are used to display keybinding hints to the user.

fn handle_key_events(&mut self, key: KeyEvent) -> Option<Action>

Handle key events and produce actions if necessary.

Arguments

• key - A key event to be processed.

Returns

• Option<Action> - An action to be processed or none.

fn handle_mouse_events(&mut self, mouse: MouseEvent) -> Option<Action>

Handle mouse events and produce actions if necessary.

Arguments

• mouse - A mouse event to be processed.

Returns

• Option<Action> - An action to be processed or none.

fn handle_tick_event(&mut self) -> Option<Action>

Handle Tick events and produce actions if necessary.

Returns

• Option<Action> - An action to be processed or none.

fn handle_frame_event(&mut self) -> Option<Action>

Handle frame events and produce actions if necessary.

Returns

• Option<Action> - An action to be processed or none.

fn handle_paste_event(&mut self, message: &str) -> Option<Action>

Handle paste events and produce actions if necessary.

Arguments

• message - A string message to be processed.

Returns

• Option<Action> - An action to be processed or none.

fn update(&mut self, action: &Action)

Update the state of the component based on a received action.

Arguments

• action - An action that may modify the state of the component.

fn on_event(&mut self, message: &str)

Receive a custom event, probably from another component.

Arguments

• message - A string message to be processed.

fn child_mut(&mut self, name: &str) -> Option<&mut Box<dyn Component>>

Get a child component by name as a mutable reference.

The method will return the child as a mutable reference to a Box<dyn Component>, which means that the caller will have to downcast it to the desired type if necessary.

let child = self.child_mut("child_name").unwrap();

if let Some(downcasted_child) = child.downcast_mut::<MyComponent>() {
   // do something with the downcasted child    
}

Arguments

• name - The name of the child component.

Returns

• Option<&mut Box<dyn Component>> - A mutable reference to the child component or none.

fn child(&mut self, name: &str) -> Option<&Box<dyn Component>>

Get a child component by name as an immutable reference.

The method will return the child as a reference to a Box<dyn Component>, which means that the caller will have to downcast it to the desired type if necessary.

let child = self.child("child_name").unwrap();

if let Some(downcasted_child) = child.downcast_ref::<MyComponent>() {
    // do something with the downcasted child
}

… or just use the [child_downcast] utility functions.

Arguments

• name - The name of the child component.

Returns

• Option<&Box<dyn Component>> - A reference to the child component or none.

fn on_active_changed(&mut self, active: bool)

Notify the component that its active state has changed.

Whenever the active state of a component changes, the component will be notified through this method. This is useful for components that need to perform some action when they are activated or deactivated.

Arguments

• active - The new active state of the component.

Implementations

impl dyn Component

pub fn is<__T>(&self) -> bool

where __T: Component,

Returns true if the trait object wraps an object of type __T.

pub fn downcast<__T>( self: Box<dyn Component>, ) -> Result<Box<__T>, Box<dyn Component>>

where __T: Component,

Returns a boxed object from a boxed trait object if the underlying object is of type __T. Returns the original boxed trait if it isn’t.

pub fn downcast_rc<__T>( self: Rc<dyn Component>, ) -> Result<Rc<__T>, Rc<dyn Component>>

where __T: Component,

Returns an Rc-ed object from an Rc-ed trait object if the underlying object is of type __T. Returns the original Rc-ed trait if it isn’t.

pub fn downcast_ref<__T>(&self) -> Option<&__T>

where __T: Component,

Returns a reference to the object within the trait object if it is of type __T, or None if it isn’t.

pub fn downcast_mut<__T>(&mut self) -> Option<&mut __T>

where __T: Component,

Returns a mutable reference to the object within the trait object if it is of type __T, or None if it isn’t.

Implementors