Need to access argument of enum - rust

Question

Working with bevy_mod_picking crate.
In the callback event when you pick a mesh the example code has:
pub fn print_events(mut events: EventReader<PickingEvent>) {
for event in events.iter() {
match event {
PickingEvent::Selection(e) => info!("selection {:?}", e),
PickingEvent::Hover(e) => info!("hover event {:?}", e),
PickingEvent::Clicked(e) => info!("click {:?}", e),
}
}
}
I need to access the Entity in all cases.
Clicked(e) is already an entity so I can modify it to use an Entity method:
PickingEvent::Clicked(e) => {
info!("click {}", e.id());
},
The others are of type:
pub enum SelectionEvent {
JustSelected(Entity),
JustDeselected(Entity),
}
and
pub enum HoverEvent {
JustEntered(Entity),
JustLeft(Entity),
}
My question is two fold:
When I run the program and select a mesh "selection JustSelected(1v0)" is printed.
1 in this case is the Entity id but I don't understand the construction 1v0. What is v in this case? Is this some sort way of printing a tuple?
Most importantly how do I modify the event handler to use the e argument of Selection(e)? As with Clicked(e) I would like to print the Entity id number of the selected mesh. Eg:
PickingEvent::Selection(e) => info!("selection {}", e/magic grammar here/.id()),
EDIT - ADDED FULL CODE FOR CONTEXT
use bevy::{
prelude::*,
window::{PresentMode, RequestRedraw},
winit::WinitSettings,
};
use bevy_mod_picking::*; // raycaster
fn main() {
App::new()
.insert_resource(Msaa { samples: 4 })
.insert_resource(WinitSettings::desktop_app())
.add_plugins(DefaultPlugins)
.add_plugins(DefaultPickingPlugins)
.add_plugin(DebugCursorPickingPlugin)
.add_startup_system(setup)
.add_system_to_stage(CoreStage::PostUpdate, print_events)
.run();
}
pub fn print_events(mut events: EventReader<PickingEvent>) {
for event in events.iter() {
match event {
PickingEvent::Selection(e) => info!("selection {:?}", e),
PickingEvent::Hover(e) => info!("hover event {:?}", e),
PickingEvent::Clicked(e) => {
info!("click {}", e.id());
},
}
}
}
fn setup(
mut commands: Commands,
asset_server: Res<AssetServer>,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
) {
let texture_handle = asset_server.load("Topo_small.png");
let icosphere_handle = meshes.add(Mesh::from(shape::Icosphere { subdivisions: 8, radius: 2.0 }));
let icosphere_material_handle = materials.add(StandardMaterial {
base_color: Color::rgb(0.8, 0.7, 0.6),
..default()
});
// this material renders the texture normally
let material_handle = materials.add(StandardMaterial {
base_color_texture: Some(texture_handle.clone()),
..default()
});
// parent icosphere
commands
.spawn_bundle(PbrBundle {
mesh: icosphere_handle.clone(),
material: material_handle,
transform: Transform::from_xyz(0.0, 0.0, 1.0),
..default()
})
.insert_bundle(PickableBundle::default());
// light
commands.spawn_bundle(PointLightBundle {
transform: Transform::from_xyz(4.0, 5.0, -4.0),
..default()
});
// camera
commands.spawn_bundle(PerspectiveCameraBundle {
transform: Transform::from_xyz(5.0, 10.0, 10.0).looking_at(Vec3::ZERO, Vec3::Y),
..default()
})
.insert_bundle(PickingCameraBundle::default());
}

Answer 1

Based on the comment I was actually able to get it by modifying the Selection match to:
PickingEvent::Selection(e) => {
if let SelectionEvent::JustSelected(e) = e {
info!("selection ID {}", e.id());
}
info!("selection {:?}", e)
},

Answer 2

So I've run into the same problem and based on the proposed solution, I elaborated a bit more :
By using a Query, you can actually find the interactable entity (eg. hovered) and get its components from the Query:
pub fn select_and_change_color(
mut events: EventReader<PickingEvent>,
mut materials: ResMut<Assets<StandardMaterial>>,
query: Query<(Entity, &Handle<StandardMaterial>)>,
) {
for event in events.iter() {
match event {
PickingEvent::Selection(e) => {
if let SelectionEvent::JustSelected(selected_entity) = e {
// retrieve the selected entity in the query
let (entity, material_handle) = query.get(*selected_entity).unwrap();
// Now you have access to both the entity and one of its
// component: its material. You can for example change the color of it.
let material = materials.get_mut(material_handle).unwrap();
material.base_color = Color::rgb(0.9, 0.1, 0.9);
}
},
PickingEvent::Hover(e) => info!("hover event {:?}", e),
PickingEvent::Clicked(e) => {
info!("click {}", e.id());
},
}
}
}
The parameter materials is a Unique mutable borrow of a resource and gives you a way to retrieve assets from the World.