Trait HasFocus

Source

pub trait HasFocus {
    // Required methods
    fn focus(&self) -> FocusFlag;
    fn area(&self) -> Rect;

    // Provided methods
    fn build(&self, builder: &mut FocusBuilder) { ... }
    fn area_z(&self) -> u16 { ... }
    fn navigable(&self) -> Navigation { ... }
    fn is_focused(&self) -> bool { ... }
    fn lost_focus(&self) -> bool { ... }
    fn gained_focus(&self) -> bool { ... }
}

Expand description

Trait for a widget that has a focus flag.

When used for a widget implement

focus()
area() and optionally
area_z() and navigable()

When used for a container widget implement

build()

    fn build(&self, builder: &mut FocusBuilder) {
        let tag = builder.start(self);
        builder.widget(&self.component_a);
        builder.widget(&self.component_b);
        builder.end(tag);
    }

Creates a container with an identity.

Or just

    fn build(&self, builder: &mut FocusBuilder) {
        builder.widget(&self.component_a);
        builder.widget(&self.component_b);
    }

for an anonymous container.

focus(), area() and area_z() are only used for the first case. navigable() is ignored for containers, leave it at the default.

Required Methods§

Source

fn focus(&self) -> FocusFlag

Access to the flag for the rest.

Source

fn area(&self) -> Rect

Area for mouse focus.

This area shouldn’t overlap with areas returned by other widgets. If it does, the widget should use z_areas() for clarification. Otherwise, the areas are searched in order of addition.