feat: Inventory mouse scroll & visible item data

src/ui/inventory/bundles.rs

@@ -8,6 +8,8 @@ use bevy::{
     },
 };
 
+use crate::item::ItemData;
+
 use super::*;
 
 pub fn ui_manager_bundle(children: Vec<Entity>, aligned_left: bool) -> impl Bundle {
@@ -29,6 +31,7 @@ pub fn ui_manager_bundle(children: Vec<Entity>, aligned_left: bool) -> impl Bund
         GlobalZIndex::default(),
         Children::spawn(SpawnWith(move |parent: &mut RelatedSpawner<ChildOf>| {
             let scroll_area_id = parent.spawn((
+                InventoryScrollArea,
                 Node {
                     width: percent(100.),
                     height: percent(100.),
@@ -40,7 +43,14 @@ pub fn ui_manager_bundle(children: Vec<Entity>, aligned_left: bool) -> impl Bund
                     ..default()
                 },
                 ScrollPosition(Vec2::ZERO),
-            )).add_children(children.as_slice()).id();
+                Pickable {
+                    is_hoverable: true,
+                    should_block_lower: false,
+                }
+            ))
+                .add_children(children.as_slice())
+                .observe(observers::on_scroll)
+                .id();
             parent.spawn((
                 Node {
                     min_width: px(8),
@@ -146,3 +156,46 @@ pub fn ui_item_bundle(item: &Item, item_entity: Entity, image: Handle<Image>) ->
         )),
     )
 }
+
+pub fn hovered_item_data_bundle(item_data: &ItemData) -> impl Bundle {
+    (
+        HoveredItemData,
+        Node {
+            display: Display::Flex,
+            flex_direction: FlexDirection::Column,
+            min_width: percent(100.),
+            top: percent(100.),
+            align_self: AlignSelf::Start,
+            justify_self: JustifySelf::Center,
+            overflow: Overflow::visible(),
+            border: UiRect::all(px(1.)),
+            ..default()
+        },
+        BackgroundColor(Color::hsla(0., 0., 0.3, 0.8)),
+        BorderColor::all(Color::BLACK),
+        Pickable::IGNORE,
+        Name::new("HoveredItemData"),
+        children![
+            (
+                Text::new(item_data.name.clone()),
+                TextFont {
+                    font_size: 24.,
+                    ..default()
+                },
+                TextLayout::new_with_justify(Justify::Center),
+                TextColor::WHITE,
+                Pickable::IGNORE,
+            ),
+            (
+                Text::new(item_data.description.clone()),
+                TextFont {
+                    font_size: 14.,
+                    ..default()
+                },
+                TextLayout::new(Justify::Justified, LineBreak::WordBoundary),
+                TextColor(Color::hsl(0., 0., 0.8)),
+                Pickable::IGNORE,
+            ),
+        ],
+    )
+}

src/ui/inventory/mod.rs

@@ -19,6 +19,15 @@ pub mod systems;
 #[require(Node)]
 pub struct UiInventoryManager;
 
+#[derive(Component, Debug, PartialEq, Eq, Default, Clone, Copy, Reflect)]
+#[reflect(Component, Debug, PartialEq, Default, Clone)]
+#[require(Node)]
+pub struct InventoryScrollArea;
+
+#[derive(Component, Debug, PartialEq, Eq, Default, Clone, Copy, Reflect)]
+#[reflect(Component, Debug, PartialEq, Default, Clone)]
+pub struct HoveredScrollArea;
+
 #[derive(Component, Debug, PartialEq, Eq, Clone, Copy, Reflect)]
 #[reflect(Component, Debug, PartialEq, Clone)]
 #[require(Node)]
@@ -38,6 +47,11 @@ pub struct UiItem(pub Entity);
 #[reflect(Component, Debug, PartialEq, Default, Clone)]
 pub struct HoveredItem;
 
+#[derive(Component, Debug, PartialEq, Eq, Clone, Copy, Reflect)]
+#[reflect(Component, Debug, PartialEq, Clone)]
+#[require(Node)]
+pub struct HoveredItemData;
+
 #[derive(Component, Debug, PartialEq, Eq, Default, Clone, Copy, Reflect)]
 #[reflect(Component, Debug, PartialEq, Default, Clone)]
 pub struct HoveredSlot;

src/ui/inventory/observers.rs

@@ -1,7 +1,28 @@
 use bevy::prelude::*;
+use bevy_input::mouse::MouseScrollUnit;
+
+use crate::item::ItemData;
 
 use super::*;
 
+pub fn on_scroll(
+    e: On<Pointer<Scroll>>,
+    mut q: Query<&mut ScrollPosition, With<InventoryScrollArea>>,
+) {
+    let Ok(mut scroll_position) = q.get_mut(e.event_target()) else {
+        return;
+    };
+    
+    let multiplier = match e.unit {
+        MouseScrollUnit::Line => {
+            MouseScrollUnit::SCROLL_UNIT_CONVERSION_FACTOR
+        },
+        MouseScrollUnit::Pixel => 1.,
+    };
+
+    scroll_position.0.y -= e.y * multiplier;
+}
+
 pub fn on_slot_over(
     e: On<Pointer<Over>>,
     mut commands: Commands,
@@ -29,14 +50,20 @@ pub fn on_slot_out(e: On<Pointer<Out>>, mut query: Query<&mut ImageNode, With<Ui
 pub fn on_item_over(
     e: On<Pointer<Over>>,
     mut commands: Commands,
-    query: Query<(), With<UiItem>>,
+    ui_item_query: Query<&UiItem>,
+    item_data_query: Query<&ItemData>,
     has_hovered_item: Option<Single<(), With<HoveredItem>>>,
 ) {
     if has_hovered_item.is_some() {
         return;
     }
-    if let Ok(_) = query.get(e.event_target()) {
-        commands.entity(e.event_target()).insert(HoveredItem);
+    if let Ok(UiItem(item_id)) = ui_item_query.get(e.event_target()) {
+        let Ok(item_data) = item_data_query.get(*item_id) else {
+            error!("UiItem {} is pointing to non-existing Item", e.event_target());
+            return;
+        };
+        commands.entity(e.event_target()).insert(HoveredItem)
+            .with_child(bundles::hovered_item_data_bundle(item_data));
     }
 }
 
@@ -46,7 +73,8 @@ pub fn on_item_out(
     query: Query<(), (With<UiItem>, With<HoveredItem>)>,
 ) {
     if let Ok(_) = query.get(e.event_target()) {
-        commands.entity(e.event_target()).remove::<HoveredItem>();
+        commands.entity(e.event_target()).remove::<HoveredItem>()
+            .despawn_children();
     }
 }
 

src/ui/inventory/systems.rs

@@ -4,7 +4,7 @@ use crate::{
     inventory::ActiveInventory,
     item::{
         Item,
-        ItemImage,
+        ItemData,
     },
     player::Player,
     ui::UiRoot,
@@ -25,7 +25,7 @@ pub fn setup_ui_inventory(
     player_query: Query<(), With<Player>>,
     active_inventory_query: Query<Entity, With<ActiveInventory>>,
     item_query: Query<&Item>,
-    item_image_query: Query<&ItemImage>,
+    item_image_query: Query<&ItemData>,
     root_query: Query<Entity, With<UiRoot>>,
 ) {
     let Ok(root) = root_query.single() else {
@@ -57,12 +57,12 @@ pub fn setup_ui_inventory(
                     match item_query.get(item_entity) {
                         Ok(item) => {
                             let item_image = item_image_query.get(item_entity)
-                                .expect("ItemImage is required on Item");
-                            Some((item, item_entity, item_image))
+                                .expect("ItemData is required on Item");
+                            Some((item, item_entity, &item_image.image))
                         },
                         Err(_) => None,
                     }
-                }).collect::<Vec<(&Item, Entity, &ItemImage)>>()
+                }).collect::<Vec<(&Item, Entity, &Handle<Image>)>>()
             }
             None => Vec::new(),
         };
@@ -76,7 +76,7 @@ pub fn setup_ui_inventory(
                     if let Some((item, entity, item_image)) = items.iter()
                         .find(|(i, _, _)| i.position == UVec2::new(x, y)) {
                         slot_commands.with_children(|commands| {
-                            commands.spawn(ui_item_bundle(item, *entity, item_image.0.clone()))
+                            commands.spawn(ui_item_bundle(item, *entity, (*item_image).clone()))
                                 .observe(on_item_over)
                                 .observe(on_item_out)
                                 .observe(on_item_drag_start)