add basic drag drop window

module/applications/sheets/items/armor.mjs

@@ -4,7 +4,13 @@ export default class ArmorSheet extends DHBaseItemSheet {
     /**@inheritdoc */
     static DEFAULT_OPTIONS = {
         classes: ['armor'],
-        dragDrop: [{ dragSelector: null, dropSelector: null }],
+        dragDrop: [
+            { dragSelector: null, dropSelector: null },
+            { dragSelector: null, dropSelector: '.attachments-section' }
+        ],
+        actions: {
+            removeAttachment: ArmorSheet.#removeAttachment
+        },
         tagifyConfigs: [
             {
                 selector: '.features-input',
@@ -26,6 +32,19 @@ export default class ArmorSheet extends DHBaseItemSheet {
         settings: {
             template: 'systems/daggerheart/templates/sheets/items/armor/settings.hbs',
             scrollable: ['.settings']
+        },
+        attachments: {
+            template: 'systems/daggerheart/templates/sheets/items/armor/attachments.hbs',
+            scrollable: ['.attachments']
+        }
+    };
+
+    /** @override */
+    static TABS = {
+        primary: {
+            tabs: [{ id: 'description' }, { id: 'actions' }, { id: 'settings' }, { id: 'attachments' }],
+            initial: 'description',
+            labelPrefix: 'DAGGERHEART.GENERAL.Tabs'
         }
     };
 
@@ -37,6 +56,28 @@ export default class ArmorSheet extends DHBaseItemSheet {
             case 'settings':
                 context.features = this.document.system.features.map(x => x.value);
                 break;
+            case 'attachments':
+                // Prepare attached items for display
+                const attachedUUIDs = this.document.system.attached || [];
+                context.attachedItems = await Promise.all(
+                    attachedUUIDs.map(async uuid => {
+                        try {
+                            const item = await fromUuid(uuid);
+                            return {
+                                uuid: uuid,
+                                name: item?.name || 'Unknown Item',
+                                img: item?.img || 'icons/svg/item-bag.svg'
+                            };
+                        } catch (error) {
+                            return {
+                                uuid: uuid,
+                                name: 'Unknown Item',
+                                img: 'icons/svg/item-bag.svg'
+                            };
+                        }
+                    })
+                );
+                break;
         }
 
         return context;
@@ -49,4 +90,48 @@ export default class ArmorSheet extends DHBaseItemSheet {
     static async #onFeatureSelect(selectedOptions) {
         await this.document.update({ 'system.features': selectedOptions.map(x => ({ value: x.value })) });
     }
+
+    /**
+     * Handle dropping items onto the attachments section
+     * @param {DragEvent} event - The drop event
+     */
+    async _onDrop(event) {
+        const data = TextEditor.getDragEventData(event);
+        
+        // Only handle Item drops
+        if (data.type !== 'Item') return;
+        
+        // Check if dropped on attachments section
+        const attachmentsSection = event.target.closest('.attachments-section');
+        if (!attachmentsSection) return super._onDrop(event);
+        
+        // Get the item being dropped
+        const item = await Item.implementation.fromDropData(data);
+        if (!item) return;
+        
+        // Get current attached UUIDs
+        const currentAttached = this.document.system.attached || [];
+        const newUUID = item.uuid;
+        
+        // Prevent duplicates
+        if (currentAttached.includes(newUUID)) return;
+        
+        await this.document.update({
+            'system.attached': [...currentAttached, newUUID]
+        });
+    }
+
+    /**
+     * Remove an attached item
+     * @param {Event} event - The click event
+     * @param {HTMLElement} target - The clicked element
+     */
+    static async #removeAttachment(event, target) {
+        const uuid = target.dataset.uuid;
+        const currentAttached = this.document.system.attached || [];
+        
+        await this.document.update({
+            'system.attached': currentAttached.filter(attachedUuid => attachedUuid !== uuid)
+        });
+    }
 }

module/data/item/armor.mjs

@@ -40,6 +40,7 @@ export default class DHArmor extends BaseDataItem {
                 major: new fields.NumberField({ integer: true, initial: 0 }),
                 severe: new fields.NumberField({ integer: true, initial: 0 })
             }),
+            attached: new fields.ArrayField(new fields.StringField()),
             actions: new fields.ArrayField(new ActionField())
         };
     }