Struct widgetry::mapspace::world::World

pub struct World<ID: ObjectID> {
    objects: HashMap<ID, Object<ID>>,
    quadtree: QuadTree<ID>,
    draw_master_batches: Vec<ToggleZoomed>,
    hovering: Option<ID>,
    dragging_from: Option<(Pt2D, bool)>,
}

A World manages objects that exist in “map-space”, the zoomable and pannable canvas. These objects can be drawn, hovered on, clicked, dragged, etc.

Fields

objects: HashMap<ID, Object<ID>>

quadtree: QuadTree<ID>

draw_master_batches: Vec<ToggleZoomed>

hovering: Option<ID>

dragging_from: Option<(Pt2D, bool)>

Implementations

impl<ID: ObjectID> World<ID>

pub fn unbounded() -> World<ID>

Creates an empty World, whose objects can exist anywhere from (0, 0) to the max f64.

pub fn bounded(bounds: &Bounds) -> World<ID>

Creates an empty World, whose objects can exist in the provided rectangular boundary.

pub fn add<'a>(&'a mut self, id: ID) -> ObjectBuilder<'a, ID>

Start adding an object to the World. The caller should specify the object with methods on ObjectBuilder, then call build.

pub fn initialize_hover(&mut self, ctx: &EventCtx<'_>)

After adding all objects to a World, call this to initially detect if the cursor is hovering on an object.

pub fn rebuilt_during_drag(&mut self, prev_world: &World<ID>)

If a drag event causes the world to be totally rebuilt, call this with the previous world to preserve the ongoing drag.

This should be called after initialize_hover.

Important: the rebuilt world must include the same object ID that’s currently being dragged from the previous world.

pub fn draw_master_batch<I: Into<ToggleZoomedBuilder>>(
    &mut self,
    ctx: &EventCtx<'_>,
    draw: I
)

Draw something underneath all objects. This is useful for performance, when a large number of objects never change appearance.

pub fn event(&mut self, ctx: &mut EventCtx<'_>) -> WorldOutcome<ID>

Let objects in the world respond to something happening.

fn calculate_hover(&self, cursor: Pt2D) -> Option<ID>

pub fn draw(&self, g: &mut GfxCtx<'_>)

Draw objects in the world that’re currently visible.

impl World<DummyID>

pub fn add_unnamed<'a>(&'a mut self) -> ObjectBuilder<'a, DummyID>

Begin adding an unnamed object to the World.

Note: You must call build on this object before calling add_unnamed again. Otherwise, the object IDs will collide.