Get width and height from an image in Bevy - bevy

Question

I am fairly new to Bevy and rust. I want to load an png image and get the width and height of it. The code below does not print "found resource ...".
fn setup( mut commands: Commands,
asset_server: Res<AssetServer>,
mut materials: ResMut<Assets<Image>>) {
let texture_handle = asset_server.load("board.png");
//materials.add(texture_handle.clone().into()); //Gives error: the trait `From<Handle<_>>` is not implemented for `bevy::prelude::Image`
commands.spawn().insert_bundle(SpriteBundle {
texture: texture_handle.clone(),
..Default::default()
}).insert(BackgroundSprite);
if let Some(image) = materials.get(texture_handle) {
print!("found resource with width and height: [{},{}]", image.texture_descriptor.size.width, image.texture_descriptor.size.height);
}
}

Answer 1

I figured it out after some help on the Bevy Discord help channle.
Resources are loaded asynchronously and has to be accessed at a later point. See AssetEvent example here
I am a beginner when it comes to Rust so I wont say this is the way to do it. But here is my result:
#[derive(Component)]
pub struct BackgroundHandle {
handle: Handle<Image>,
}
#[derive(Component)]
pub struct BackgroundSpriteSize {
width: u32,
height: u32,
}
fn setup( mut commands: Commands,
mut app_state: ResMut<State<BoardState>>,
asset_server: Res<AssetServer>) {
let texture_handle = asset_server.load("board.png");
commands.spawn().insert_bundle(SpriteBundle {
texture: texture_handle.clone(),
..Default::default()
}).insert(BackgroundSpriteBundle);
commands.insert_resource(BackgroundHandle {
handle: texture_handle,
});
app_state.set(BoardState::Initializing);
}
fn setupBounds(mut commands: Commands,
mut app_state: ResMut<State<BoardState>>,
mut ev_asset: EventReader<AssetEvent<Image>>,
assets: Res<Assets<Image>>,
bg: Res<BackgroundHandle>) {
for ev in ev_asset.iter() {
match ev {
AssetEvent::Created { handle } => {
if *handle == bg.handle {
let img = assets.get(bg.handle.clone()).unwrap();
let bg_size = BackgroundSpriteSize {
width: img.texture_descriptor.size.width,
height: img.texture_descriptor.size.height,
};
commands.insert_resource(bg_size);
app_state.set(BoardState::Initialized);
}
},
_ => {
}
}
}
}