Event handling

For a component to receive events it has to enable event handling by implementing one or more of the following methods:

`on_mount`

Event called when a component is added to the tree.

fn on_init(
    &mut self,
    state: &mut Self::State,
    mut children: Children<'_, '_>,
    mut context: Context<'_, '_, Self::State>,
) { }

`on_unmount`

Event called when a component is removed from the tree and returned to component storage.

fn on_unmount(
    &mut self,
    state: &mut Self::State,
    mut children: Children<'_, '_>,
    mut context: Context<'_, '_, Self::State>,
) { }

`on_key`

Accept a key event and a mutable reference to the state.

fn on_key(
    &mut self,
    key: KeyEvent,
    state: &mut Self::State,
    mut children: Children<'_, '_>,
    mut context: Context<'_, '_, Self::State>,
) { }

on_mouse

Accept a mouse event and a mutable reference to the state.

fn on_mouse(
    &mut self,
    mouse: MouseEvent,
    state: &mut Self::State,
    mut children: Children<'_, '_>,
    mut context: Context<'_, '_, Self::State>,
) { }

on_focus

The component gained focus.

fn on_focus(
    &mut self,
    state: &mut Self::State,
    mut children: Children<'_, '_>,
    mut context: Context<'_, '_, Self::State>,
) { }

on_blur

The component lost focus.

fn on_blur(
    &mut self,
    state: &mut Self::State,
    mut children: Children<'_, '_>,
    mut context: Context<'_, '_, Self::State>,
) {}

on_tick

Issued every frame by the runtime.

By default every component has ??. To stop a component from receiving tick events set ?? to false.

fn on_tick(
    &mut self,
    state: &mut Self::State,
    mut children: Children<'_, '_>,
    context: Context<'_, '_, Self::State>,
    dt: Duration,
) {
}

on_resize

Issues when the backend is resized.

fn on_resize(
    &mut self,
    state: &mut Self::State,
    mut children: Children<'_, '_>,
    mut context: Context<'_, '_, Self::State>,
) {
}

on_event

This is issued if a child component emits an event using context.publish().

fn on_event(
    &mut self,
    event: &mut UserEvent<'_>,
    state: &mut Self::State,
    mut children: Children<'_, '_>,
    mut context: Context<'_, '_, Self::State>,
) {
}

Example

use anathema::widgets::components::events::{KeyCode, KeyEvent, MouseEvent};
use anathema::widgets::Elements;

impl Component for MyComponent {
    type Message = ();
    type State = MyState;

    fn on_key(
        &mut self,
        key: KeyEvent,
        state: &mut Self::State,
        mut children: Children<'_, '_>,
        mut context: Context<'_, '_, Self::State>,
    ) {
        // Get mutable access to the name
        let mut name = state.name.to_mut();

        if let Some(c) = key.get_char() {
            name.push(c);
        }

        if let KeyCode::Enter = key.code {
            name.clear();
        }
    }

    fn on_mouse(
        &mut self,
        mouse: MouseEvent,
        state: &mut Self::State,
        mut children: Children<'_, '_>,
        mut context: Context<'_, '_, Self::State>,
    ) {
        // Mouse event
    }
}

Anathema