docs/V2-ARCHITECTURE.md

@@ -0,0 +1,408 @@
+# Calendar V2 Architecture
+
+## Oversigt
+
+Calendar V2 er bygget med en event-driven arkitektur og et fleksibelt grouping-system der tillader forskellige kalendervisninger (dag, uge, ressource, team).
+
+---
+
+## Event System
+
+### CoreEvents Katalog
+
+Alle events er defineret i `src/v2/constants/CoreEvents.ts`.
+
+#### Drag-Drop Events
+
+| Event | Payload | Emitter | Subscribers |
+|-------|---------|---------|-------------|
+| `event:drag-start` | `IDragStartPayload` | DragDropManager | EdgeScrollManager |
+| `event:drag-move` | `IDragMovePayload` | DragDropManager | EventRenderer |
+| `event:drag-end` | `IDragEndPayload` | DragDropManager | EdgeScrollManager |
+| `event:drag-cancel` | `IDragCancelPayload` | DragDropManager | EdgeScrollManager |
+| `event:drag-column-change` | `IDragColumnChangePayload` | DragDropManager | EventRenderer |
+
+#### Resize Events
+
+| Event | Payload | Emitter | Subscribers |
+|-------|---------|---------|-------------|
+| `event:resize-start` | `IResizeStartPayload` | ResizeManager | - |
+| `event:resize-end` | `IResizeEndPayload` | ResizeManager | - |
+
+#### Edge Scroll Events
+
+| Event | Payload | Emitter | Subscribers |
+|-------|---------|---------|-------------|
+| `edge-scroll:tick` | `{ scrollDelta: number }` | EdgeScrollManager | DragDropManager |
+| `edge-scroll:started` | `{}` | EdgeScrollManager | - |
+| `edge-scroll:stopped` | `{}` | EdgeScrollManager | - |
+
+#### Lifecycle Events
+
+| Event | Purpose |
+|-------|---------|
+| `core:initialized` | DI container klar |
+| `core:ready` | Kalender fuldt initialiseret |
+| `core:destroyed` | Cleanup færdig |
+
+#### Data Events
+
+| Event | Purpose |
+|-------|---------|
+| `data:loading` | Data fetch startet |
+| `data:loaded` | Data fetch færdig |
+| `data:error` | Data fetch fejlet |
+| `entity:saved` | Entity gemt i IndexedDB |
+| `entity:deleted` | Entity slettet fra IndexedDB |
+
+#### View Events
+
+| Event | Purpose |
+|-------|---------|
+| `view:changed` | View/grouping ændret |
+| `view:rendered` | View rendering færdig |
+| `events:rendered` | Events renderet til DOM |
+| `grid:rendered` | Time grid renderet |
+
+---
+
+## Event Flows
+
+### Drag-Drop Flow
+
+```
+pointerdown på event
+    └── DragDropManager.handlePointerDown()
+        └── Gem mouseDownPosition, capture pointer
+
+pointermove (>5px)
+    └── DragDropManager.initializeDrag()
+        ├── Opret ghost clone (opacity 0.3)
+        ├── Marker original med .dragging
+        ├── EMIT: event:drag-start
+        │   └── EdgeScrollManager starter scrollTick loop
+        └── Start animateDrag() RAF loop
+
+pointermove (under drag)
+    ├── DragDropManager.updateDragTarget()
+    │   ├── Detect kolonneændring
+    │   │   └── EMIT: event:drag-column-change
+    │   │       └── EventRenderer flytter element til ny kolonne
+    │   └── Beregn targetY for smooth interpolation
+    │
+    └── DragDropManager.animateDrag() (RAF)
+        ├── Interpoler currentY mod targetY (factor 0.3)
+        ├── Opdater element.style.top
+        └── EMIT: event:drag-move
+            └── EventRenderer.updateDragTimestamp()
+                └── Beregn snapped tid og opdater visning
+
+EdgeScrollManager.scrollTick() (parallel RAF)
+    ├── Beregn velocity baseret på museafstand til kanter
+    │   - Inner zone (0-50px): 640 px/sek
+    │   - Outer zone (50-100px): 140 px/sek
+    ├── Scroll viewport: scrollTop += scrollDelta
+    └── EMIT: edge-scroll:tick
+        └── DragDropManager kompenserer element position
+
+pointerup
+    └── DragDropManager.handlePointerUp()
+        ├── Snap currentY til grid (15-min intervaller)
+        ├── Fjern ghost element
+        ├── EMIT: event:drag-end
+        │   └── EdgeScrollManager stopper scroll
+        └── Persist ændringer til IndexedDB
+```
+
+---
+
+## Grouping System
+
+### ViewConfig
+
+```typescript
+interface ViewConfig {
+  templateId: string;           // 'day' | 'simple' | 'resource' | 'team'
+  groupings: GroupingConfig[];
+}
+
+interface GroupingConfig {
+  type: string;                 // 'date' | 'resource' | 'team'
+  values: string[];             // IDs der skal vises
+}
+```
+
+### Sådan bestemmer groupings strukturen
+
+1. **Kolonneantal**: Produkt af alle grouping dimensioner
+   - Eksempel: `5 datoer × 2 ressourcer = 10 kolonner`
+
+2. **Header layout**: CSS grid bruger `data-levels` til at stakke headers
+   - `data-levels="date"` → 1 header række
+   - `data-levels="resource date"` → 2 header rækker
+   - `data-levels="team resource date"` → 3 header rækker
+
+3. **Renderer selektion**: Grouping types matches til tilgængelige renderers
+
+### Konfigurationseksempler
+
+#### Simple Date View (3 dage, ingen ressourcer)
+
+```typescript
+{
+  templateId: 'simple',
+  groupings: [
+    { type: 'date', values: ['2024-01-15', '2024-01-16', '2024-01-17'] }
+  ]
+}
+```
+
+**Resultat:** 3 kolonner, 1 header række
+
+```
+┌─── Date1 ───┬─── Date2 ───┬─── Date3 ───┐
+│             │             │             │
+```
+
+#### Resource View (2 ressourcer, 3 dage)
+
+```typescript
+{
+  templateId: 'resource',
+  groupings: [
+    { type: 'resource', values: ['EMP001', 'EMP002'] },
+    { type: 'date', values: ['2024-01-15', '2024-01-16', '2024-01-17'] }
+  ]
+}
+```
+
+**Resultat:** 6 kolonner, 2 header rækker
+
+```
+┌───── Resource1 (span 3) ─────┬───── Resource2 (span 3) ─────┐
+├─── D1 ───┬─── D2 ───┬─── D3 ─┼─── D1 ───┬─── D2 ───┬─── D3 ─┤
+│          │          │        │          │          │        │
+```
+
+#### Team View (2 teams, 2 ressourcer, 3 dage)
+
+```typescript
+{
+  templateId: 'team',
+  groupings: [
+    { type: 'team', values: ['team1', 'team2'] },
+    { type: 'resource', values: ['res1', 'res2'] },
+    { type: 'date', values: ['2024-01-15', '2024-01-16', '2024-01-17'] }
+  ]
+}
+```
+
+**Resultat:** 12 kolonner, 3 header rækker
+
+```
+┌─────────── Team1 (span 6) ───────────┬─────────── Team2 (span 6) ───────────┐
+├───── Res1 (span 3) ──┬── Res2 (3) ───┼───── Res1 (span 3) ──┬── Res2 (3) ───┤
+├── D1 ─┬── D2 ─┬── D3 ┼── D1 ─┬── D2 ─┼── D1 ─┬── D2 ─┬── D3 ┼── D1 ─┬── D2 ─┤
+│       │       │      │       │       │       │       │      │       │       │
+```
+
+---
+
+## Header Rendering
+
+### data-levels Attribut
+
+`swp-calendar-header` modtager `data-levels` som bestemmer header row layout:
+
+```typescript
+// I CalendarOrchestrator.render()
+const levels = viewConfig.groupings.map(g => g.type).join(' ');
+headerContainer.dataset.levels = levels;  // "resource date" eller "team resource date"
+```
+
+### CSS Grid Styling
+
+```css
+swp-calendar-header[data-levels="date"] > swp-day-header {
+  grid-row: 1;
+}
+
+swp-calendar-header[data-levels="resource date"] {
+  > swp-resource-header { grid-row: 1; }
+  > swp-day-header { grid-row: 2; }
+}
+
+swp-calendar-header[data-levels="team resource date"] {
+  > swp-team-header { grid-row: 1; }
+  > swp-resource-header { grid-row: 2; }
+  > swp-day-header { grid-row: 3; }
+}
+```
+
+### Rendering Pipeline
+
+1. Renderers eksekveres i den rækkefølge de står i `viewConfig.groupings`
+2. Hver renderer APPENDER sine headers til `headerContainer`
+3. CSS bruger `data-levels` + element type til at positionere i korrekt række
+
+---
+
+## Renderers
+
+### DateRenderer
+
+```typescript
+class DateRenderer implements IRenderer {
+  readonly type = 'date';
+
+  render(context: IRenderContext): void {
+    // For HVER ressource (eller én gang hvis ingen):
+    //   For HVER dato i filter['date']:
+    //     Opret swp-day-header + swp-day-column
+    //     Sæt dataset.date & dataset.resourceId
+  }
+}
+```
+
+### ResourceRenderer
+
+```typescript
+class ResourceRenderer implements IRenderer {
+  readonly type = 'resource';
+
+  async render(context: IRenderContext): Promise<void> {
+    // Load IResource[] fra ResourceService
+    // For HVER ressource:
+    //   Opret swp-resource-header
+    //   Sæt grid-column: span ${dateCount}
+  }
+}
+```
+
+### TeamRenderer
+
+```typescript
+class TeamRenderer implements IRenderer {
+  readonly type = 'team';
+
+  render(context: IRenderContext): void {
+    // For HVERT team:
+    //   Tæl ressourcer der tilhører team
+    //   Opret swp-team-header
+    //   Sæt grid-column: span ${colspan}
+  }
+}
+```
+
+---
+
+## Grid Konfiguration
+
+### IGridConfig
+
+```typescript
+interface IGridConfig {
+  hourHeight: number;      // pixels per time (fx 60)
+  dayStartHour: number;    // fx 6 (06:00)
+  dayEndHour: number;      // fx 18 (18:00)
+  snapInterval: number;    // minutter (fx 15)
+}
+```
+
+### Position Beregning
+
+```typescript
+function calculateEventPosition(start: Date, end: Date, config: IGridConfig): EventPosition {
+  const startMinutes = start.getHours() * 60 + start.getMinutes();
+  const endMinutes = end.getHours() * 60 + end.getMinutes();
+
+  const dayStartMinutes = config.dayStartHour * 60;
+  const minuteHeight = config.hourHeight / 60;
+
+  return {
+    top: (startMinutes - dayStartMinutes) * minuteHeight,
+    height: (endMinutes - startMinutes) * minuteHeight
+  };
+}
+```
+
+**Eksempel:** Event 09:00-10:00 med dayStartHour=6, hourHeight=60
+- startMinutes = 540, dayStartMinutes = 360
+- top = (540 - 360) × 1 = **180px**
+- height = (600 - 540) × 1 = **60px**
+
+---
+
+## Z-Index Stack
+
+```
+z-index: 10  ← Events (interaktive, draggable)
+z-index: 5   ← Unavailable zones (visuel, pointer-events: none)
+z-index: 2   ← Time linjer (baggrund)
+z-index: 1   ← Kvarter linjer (baggrund)
+z-index: 0   ← Grid baggrund
+```
+
+---
+
+## Komponenter
+
+| Komponent | Ansvar | Fil |
+|-----------|--------|-----|
+| **CalendarOrchestrator** | Orkestrerer renderer pipeline | `core/CalendarOrchestrator.ts` |
+| **DateRenderer** | Opretter dag-headers og kolonner | `features/date/DateRenderer.ts` |
+| **ResourceRenderer** | Opretter ressource-headers | `features/resource/ResourceRenderer.ts` |
+| **TeamRenderer** | Opretter team-headers | `features/team/TeamRenderer.ts` |
+| **EventRenderer** | Renderer events med positioner | `features/event/EventRenderer.ts` |
+| **ScheduleRenderer** | Renderer unavailable zoner | `features/schedule/ScheduleRenderer.ts` |
+| **DragDropManager** | Håndterer drag-drop | `managers/DragDropManager.ts` |
+| **ResizeManager** | Håndterer event resize | `managers/ResizeManager.ts` |
+| **EdgeScrollManager** | Auto-scroll ved kanter | `managers/EdgeScrollManager.ts` |
+| **ScrollManager** | Synkroniserer scroll | `core/ScrollManager.ts` |
+| **EventBus** | Central event dispatcher | `core/EventBus.ts` |
+| **DateService** | Dato formatering og beregning | `core/DateService.ts` |
+
+---
+
+## Filer
+
+```
+src/v2/
+├── constants/
+│   └── CoreEvents.ts          # Alle event konstanter
+├── core/
+│   ├── CalendarOrchestrator.ts
+│   ├── DateService.ts
+│   ├── EventBus.ts
+│   ├── IGridConfig.ts
+│   ├── IGroupingRenderer.ts
+│   ├── RenderBuilder.ts
+│   ├── ScrollManager.ts
+│   └── ViewConfig.ts
+├── features/
+│   ├── date/
+│   │   └── DateRenderer.ts
+│   ├── event/
+│   │   └── EventRenderer.ts
+│   ├── resource/
+│   │   └── ResourceRenderer.ts
+│   ├── schedule/
+│   │   └── ScheduleRenderer.ts
+│   └── team/
+│       └── TeamRenderer.ts
+├── managers/
+│   ├── DragDropManager.ts
+│   └── EdgeScrollManager.ts
+├── storage/
+│   ├── BaseEntityService.ts
+│   ├── IndexedDBContext.ts
+│   └── events/
+│       ├── EventService.ts
+│       └── EventStore.ts
+├── types/
+│   ├── CalendarTypes.ts
+│   ├── DragTypes.ts
+│   └── ScheduleTypes.ts
+└── utils/
+    └── PositionUtils.ts
+```

src/v2/V2CompositionRoot.ts

@@ -44,6 +44,7 @@ import { DataSeeder } from './workers/DataSeeder';
 // Features
 import { EventRenderer } from './features/event/EventRenderer';
 import { ScheduleRenderer } from './features/schedule/ScheduleRenderer';
+import { HeaderDrawerRenderer } from './features/headerdrawer/HeaderDrawerRenderer';
 
 // Schedule
 import { ScheduleOverrideStore } from './storage/schedules/ScheduleOverrideStore';
@@ -135,6 +136,7 @@ export function createV2Container(): Container {
   // Features
   builder.registerType(EventRenderer).as<EventRenderer>();
   builder.registerType(ScheduleRenderer).as<ScheduleRenderer>();
+  builder.registerType(HeaderDrawerRenderer).as<HeaderDrawerRenderer>();
 
   // Renderers - registreres som Renderer (array injection til CalendarOrchestrator)
   builder.registerType(DateRenderer).as<IRenderer>();

src/v2/constants/CoreEvents.ts

@@ -37,6 +37,11 @@ export const CoreEvents = {
   EVENT_DRAG_CANCEL: 'event:drag-cancel',
   EVENT_DRAG_COLUMN_CHANGE: 'event:drag-column-change',
 
+  // Header drag (timed → header conversion)
+  EVENT_DRAG_ENTER_HEADER: 'event:drag-enter-header',
+  EVENT_DRAG_MOVE_HEADER: 'event:drag-move-header',
+  EVENT_DRAG_LEAVE_HEADER: 'event:drag-leave-header',
+
   // Event resize
   EVENT_RESIZE_START: 'event:resize-start',
   EVENT_RESIZE_END: 'event:resize-end',

src/v2/demo/DemoApp.ts

@@ -10,6 +10,7 @@ import { ViewConfig } from '../core/ViewConfig';
 import { DragDropManager } from '../managers/DragDropManager';
 import { EdgeScrollManager } from '../managers/EdgeScrollManager';
 import { ResizeManager } from '../managers/ResizeManager';
+import { HeaderDrawerRenderer } from '../features/headerdrawer/HeaderDrawerRenderer';
 
 export class DemoApp {
   private animator!: NavigationAnimator;
@@ -27,7 +28,8 @@ export class DemoApp {
     private dataSeeder: DataSeeder,
     private dragDropManager: DragDropManager,
     private edgeScrollManager: EdgeScrollManager,
-    private resizeManager: ResizeManager
+    private resizeManager: ResizeManager,
+    private headerDrawerRenderer: HeaderDrawerRenderer
   ) {}
 
   async init(): Promise<void> {

src/v2/features/headerdrawer/HeaderDrawerLayoutEngine.ts

@@ -0,0 +1,135 @@
+/**
+ * HeaderDrawerLayoutEngine - Calculates row placement for header items
+ *
+ * Prevents visual overlap by assigning items to different rows when
+ * they occupy the same columns. Uses a track-based algorithm similar
+ * to V1's AllDayLayoutEngine.
+ *
+ * Each row can hold multiple items as long as they don't overlap in columns.
+ * When an item spans columns that are already occupied, it's placed in the
+ * next available row.
+ */
+
+export interface IHeaderItemLayout {
+  itemId: string;
+  gridArea: string;        // "row / col-start / row+1 / col-end"
+  startColumn: number;
+  endColumn: number;
+  row: number;
+}
+
+export interface IHeaderItemInput {
+  id: string;
+  columnStart: number;     // 0-based column index
+  columnEnd: number;       // 0-based end column (inclusive)
+}
+
+export class HeaderDrawerLayoutEngine {
+  private tracks: boolean[][] = [];
+  private columnCount: number;
+
+  constructor(columnCount: number) {
+    this.columnCount = columnCount;
+    this.reset();
+  }
+
+  /**
+   * Reset tracks for new layout calculation
+   */
+  reset(): void {
+    this.tracks = [new Array(this.columnCount).fill(false)];
+  }
+
+  /**
+   * Calculate layout for all items
+   * Items should be sorted by start column for optimal packing
+   */
+  calculateLayout(items: IHeaderItemInput[]): IHeaderItemLayout[] {
+    this.reset();
+    const layouts: IHeaderItemLayout[] = [];
+
+    for (const item of items) {
+      const row = this.findAvailableRow(item.columnStart, item.columnEnd);
+
+      // Mark columns as occupied in this row
+      for (let col = item.columnStart; col <= item.columnEnd; col++) {
+        this.tracks[row][col] = true;
+      }
+
+      // gridArea format: "row / col-start / row+1 / col-end"
+      // CSS grid uses 1-based indices
+      layouts.push({
+        itemId: item.id,
+        gridArea: `${row + 1} / ${item.columnStart + 1} / ${row + 2} / ${item.columnEnd + 2}`,
+        startColumn: item.columnStart,
+        endColumn: item.columnEnd,
+        row: row + 1  // 1-based for CSS
+      });
+    }
+
+    return layouts;
+  }
+
+  /**
+   * Calculate layout for a single new item
+   * Useful for real-time drag operations
+   */
+  calculateSingleLayout(item: IHeaderItemInput): IHeaderItemLayout {
+    const row = this.findAvailableRow(item.columnStart, item.columnEnd);
+
+    // Mark columns as occupied
+    for (let col = item.columnStart; col <= item.columnEnd; col++) {
+      this.tracks[row][col] = true;
+    }
+
+    return {
+      itemId: item.id,
+      gridArea: `${row + 1} / ${item.columnStart + 1} / ${row + 2} / ${item.columnEnd + 2}`,
+      startColumn: item.columnStart,
+      endColumn: item.columnEnd,
+      row: row + 1
+    };
+  }
+
+  /**
+   * Find the first row where all columns in range are available
+   */
+  private findAvailableRow(startCol: number, endCol: number): number {
+    for (let row = 0; row < this.tracks.length; row++) {
+      if (this.isRowAvailable(row, startCol, endCol)) {
+        return row;
+      }
+    }
+
+    // Add new row if all existing rows are occupied
+    this.tracks.push(new Array(this.columnCount).fill(false));
+    return this.tracks.length - 1;
+  }
+
+  /**
+   * Check if columns in range are all available in given row
+   */
+  private isRowAvailable(row: number, startCol: number, endCol: number): boolean {
+    for (let col = startCol; col <= endCol; col++) {
+      if (this.tracks[row][col]) {
+        return false;
+      }
+    }
+    return true;
+  }
+
+  /**
+   * Get the number of rows currently in use
+   */
+  getRowCount(): number {
+    return this.tracks.length;
+  }
+
+  /**
+   * Update column count (e.g., when view changes)
+   */
+  setColumnCount(count: number): void {
+    this.columnCount = count;
+    this.reset();
+  }
+}

src/v2/features/headerdrawer/HeaderDrawerRenderer.ts

@@ -0,0 +1,151 @@
+import { IEventBus } from '../../types/CalendarTypes';
+import { IGridConfig } from '../../core/IGridConfig';
+import { CoreEvents } from '../../constants/CoreEvents';
+import {
+  IDragEnterHeaderPayload,
+  IDragMoveHeaderPayload,
+  IDragLeaveHeaderPayload
+} from '../../types/DragTypes';
+
+/**
+ * HeaderDrawerRenderer - Handles rendering of items in the header drawer
+ *
+ * Listens to drag events from DragDropManager and creates/manages
+ * swp-header-item elements in the header drawer.
+ *
+ * Uses subgrid for column alignment with parent swp-calendar-header.
+ * Position items via gridArea for explicit row/column placement.
+ */
+export class HeaderDrawerRenderer {
+  private currentItem: HTMLElement | null = null;
+  private container: HTMLElement | null = null;
+  private sourceElement: HTMLElement | null = null;
+
+  constructor(
+    private eventBus: IEventBus,
+    private gridConfig: IGridConfig
+  ) {
+    this.setupListeners();
+  }
+
+  /**
+   * Setup event listeners for drag events
+   */
+  private setupListeners(): void {
+    this.eventBus.on(CoreEvents.EVENT_DRAG_ENTER_HEADER, (e) => {
+      const payload = (e as CustomEvent<IDragEnterHeaderPayload>).detail;
+      this.handleDragEnter(payload);
+    });
+
+    this.eventBus.on(CoreEvents.EVENT_DRAG_MOVE_HEADER, (e) => {
+      const payload = (e as CustomEvent<IDragMoveHeaderPayload>).detail;
+      this.handleDragMove(payload);
+    });
+
+    this.eventBus.on(CoreEvents.EVENT_DRAG_LEAVE_HEADER, (e) => {
+      const payload = (e as CustomEvent<IDragLeaveHeaderPayload>).detail;
+      this.handleDragLeave(payload);
+    });
+
+    this.eventBus.on(CoreEvents.EVENT_DRAG_END, () => {
+      this.handleDragEnd();
+    });
+
+    this.eventBus.on(CoreEvents.EVENT_DRAG_CANCEL, () => {
+      this.cleanup();
+    });
+  }
+
+  /**
+   * Handle drag entering header zone - create preview item
+   */
+  private handleDragEnter(payload: IDragEnterHeaderPayload): void {
+    this.container = document.querySelector('swp-header-drawer');
+    if (!this.container) return;
+
+    // Store reference to source element
+    this.sourceElement = payload.element;
+
+    // Create header item
+    const item = document.createElement('swp-header-item');
+    item.dataset.id = payload.eventId;
+    item.dataset.itemType = payload.itemType;
+    item.dataset.date = payload.sourceDate;
+    item.dataset.duration = String(payload.duration);
+    item.textContent = payload.title;
+
+    // Apply color class if present
+    if (payload.colorClass) {
+      item.classList.add(payload.colorClass);
+    }
+
+    // Add dragging state
+    item.classList.add('dragging');
+
+    // Initial placement (duration determines column span)
+    // gridArea format: "row / col-start / row+1 / col-end"
+    const col = payload.sourceColumnIndex + 1;
+    const endCol = col + payload.duration;
+    item.style.gridArea = `1 / ${col} / 2 / ${endCol}`;
+
+    this.container.appendChild(item);
+    this.currentItem = item;
+
+    // Hide original element while in header
+    payload.element.style.visibility = 'hidden';
+  }
+
+  /**
+   * Handle drag moving within header - update column position
+   */
+  private handleDragMove(payload: IDragMoveHeaderPayload): void {
+    if (!this.currentItem) return;
+
+    // Update column position (duration=1 for now)
+    const col = payload.columnIndex + 1;
+    const duration = parseInt(this.currentItem.dataset.duration || '1', 10);
+    const endCol = col + duration;
+
+    this.currentItem.style.gridArea = `1 / ${col} / 2 / ${endCol}`;
+    this.currentItem.dataset.date = payload.dateKey;
+  }
+
+  /**
+   * Handle drag leaving header - remove preview and restore source
+   */
+  private handleDragLeave(_payload: IDragLeaveHeaderPayload): void {
+    this.cleanup();
+  }
+
+  /**
+   * Handle drag end - finalize the item (it stays in header)
+   */
+  private handleDragEnd(): void {
+    if (!this.currentItem) return;
+
+    // Remove dragging state
+    this.currentItem.classList.remove('dragging');
+
+    // Item stays - it's now permanent
+    // TODO: Emit event to persist allDay=true change
+
+    // Clear references but leave item in DOM
+    this.currentItem = null;
+    this.sourceElement = null;
+  }
+
+  /**
+   * Cleanup preview item and restore source visibility
+   */
+  private cleanup(): void {
+    // Remove preview item
+    this.currentItem?.remove();
+    this.currentItem = null;
+
+    // Restore source element visibility
+    if (this.sourceElement) {
+      this.sourceElement.style.visibility = '';
+      this.sourceElement = null;
+    }
+  }
+}

src/v2/features/headerdrawer/index.ts

@@ -0,0 +1,2 @@
+export { HeaderDrawerRenderer } from './HeaderDrawerRenderer';
+export { HeaderDrawerLayoutEngine, type IHeaderItemLayout, type IHeaderItemInput } from './HeaderDrawerLayoutEngine';

src/v2/managers/DragDropManager.ts

@@ -8,7 +8,10 @@ import {
   IDragMovePayload,
   IDragEndPayload,
   IDragCancelPayload,
-  IDragColumnChangePayload
+  IDragColumnChangePayload,
+  IDragEnterHeaderPayload,
+  IDragMoveHeaderPayload,
+  IDragLeaveHeaderPayload
 } from '../types/DragTypes';
 
 interface DragState {
@@ -39,6 +42,7 @@ export class DragDropManager {
   private pendingElement: HTMLElement | null = null;
   private pendingMouseOffset: IMousePosition | null = null;
   private container: HTMLElement | null = null;
+  private inHeader = false;
 
   private readonly DRAG_THRESHOLD = 5;
   private readonly INTERPOLATION_FACTOR = 0.3;
@@ -159,6 +163,7 @@ export class DragDropManager {
     // Cleanup
     this.dragState.element.classList.remove('dragging');
     this.dragState = null;
+    this.inHeader = false;
   };
 
   private initializeDrag(element: HTMLElement, mouseOffset: IMousePosition, e: PointerEvent): void {
@@ -217,6 +222,12 @@ export class DragDropManager {
   private updateDragTarget(e: PointerEvent): void {
     if (!this.dragState) return;
 
+    // Check header zone first
+    this.checkHeaderZone(e);
+
+    // Skip normal grid handling if in header
+    if (this.inHeader) return;
+
     // Check for column change
     const columnAtPoint = this.getColumnAtPoint(e.clientX);
     if (columnAtPoint && columnAtPoint !== this.dragState.currentColumn) {
@@ -244,6 +255,74 @@ export class DragDropManager {
     }
   }
 
+  /**
+   * Check if pointer is in header zone and emit appropriate events
+   */
+  private checkHeaderZone(e: PointerEvent): void {
+    if (!this.dragState) return;
+
+    const headerViewport = document.querySelector('swp-header-viewport');
+    if (!headerViewport) return;
+
+    const rect = headerViewport.getBoundingClientRect();
+    const isInHeader = e.clientY < rect.bottom;
+
+    if (isInHeader && !this.inHeader) {
+      // Entered header
+      this.inHeader = true;
+
+      const payload: IDragEnterHeaderPayload = {
+        eventId: this.dragState.eventId,
+        element: this.dragState.element,
+        sourceColumnIndex: this.getColumnIndex(this.dragState.columnElement),
+        sourceDate: this.dragState.columnElement.dataset.date || '',
+        title: this.dragState.element.querySelector('swp-event-title')?.textContent || '',
+        colorClass: [...this.dragState.element.classList].find(c => c.startsWith('is-')),
+        itemType: 'event',
+        duration: 1
+      };
+
+      this.eventBus.emit(CoreEvents.EVENT_DRAG_ENTER_HEADER, payload);
+    } else if (!isInHeader && this.inHeader) {
+      // Left header
+      this.inHeader = false;
+
+      const payload: IDragLeaveHeaderPayload = {
+        eventId: this.dragState.eventId
+      };
+
+      this.eventBus.emit(CoreEvents.EVENT_DRAG_LEAVE_HEADER, payload);
+    } else if (isInHeader) {
+      // Moving within header
+      const column = this.getColumnAtX(e.clientX);
+      if (column) {
+        const payload: IDragMoveHeaderPayload = {
+          eventId: this.dragState.eventId,
+          columnIndex: this.getColumnIndex(column),
+          dateKey: column.dataset.date || ''
+        };
+
+        this.eventBus.emit(CoreEvents.EVENT_DRAG_MOVE_HEADER, payload);
+      }
+    }
+  }
+
+  /**
+   * Get column index (0-based) for a column element
+   */
+  private getColumnIndex(column: HTMLElement): number {
+    if (!this.container) return 0;
+    const columns = Array.from(this.container.querySelectorAll('swp-day-column'));
+    return columns.indexOf(column);
+  }
+
+  /**
+   * Get column at X coordinate (alias for getColumnAtPoint)
+   */
+  private getColumnAtX(clientX: number): HTMLElement | null {
+    return this.getColumnAtPoint(clientX);
+  }
+
   /**
    * Find column element at given X coordinate
    */
@@ -323,5 +402,6 @@ export class DragDropManager {
     this.eventBus.emit(CoreEvents.EVENT_DRAG_CANCEL, payload);
 
     this.dragState = null;
+    this.inHeader = false;
   }
 }

src/v2/types/DragTypes.ts

@@ -45,3 +45,25 @@ export interface IDragColumnChangePayload {
   newColumn: HTMLElement;
   currentY: number;
 }
+
+// Header drag payloads
+export interface IDragEnterHeaderPayload {
+  eventId: string;
+  element: HTMLElement;        // Original dragged element
+  sourceColumnIndex: number;
+  sourceDate: string;
+  title: string;
+  colorClass?: string;
+  itemType: 'event' | 'reminder';
+  duration: number;            // Antal dage (default 1)
+}
+
+export interface IDragMoveHeaderPayload {
+  eventId: string;
+  columnIndex: number;
+  dateKey: string;
+}
+
+export interface IDragLeaveHeaderPayload {
+  eventId: string;
+}

wwwroot/css/v2/calendar-v2-events.css

@@ -346,3 +346,38 @@ swp-allday-container swp-event.transitioning {
 .is-amber { --b-primary: var(--b-color-amber); }
 .is-orange { --b-primary: var(--b-color-orange); }
 .is-deep-orange { --b-primary: var(--b-color-deep-orange); }
+
+/* Header drawer items */
+swp-header-item {
+  --b-text: var(--color-text);
+
+  /* Positioneres via style.gridArea */
+  height: 22px;
+  margin: 2px 4px;
+  padding: 2px 8px;
+  border-radius: 3px;
+  font-size: 0.75rem;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  display: flex;
+  align-items: center;
+  cursor: pointer;
+  user-select: none;
+  transition: background-color 200ms ease;
+
+  /* Color system fra swp-event */
+  background-color: color-mix(in srgb, var(--b-primary) 10%, var(--b-mix));
+  color: var(--b-text);
+  border-left: 4px solid var(--b-primary);
+
+  &:hover {
+    background-color: color-mix(in srgb, var(--b-primary) 15%, var(--b-mix));
+  }
+
+  /* Dragging state */
+  &.dragging {
+    opacity: 0.7;
+    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
+  }
+}

wwwroot/css/v2/calendar-v2-layout.css

@@ -73,8 +73,12 @@ swp-header-spacer {
 }
 
 swp-header-drawer {
-  display: block;
-  height: 0;
+  display: grid;
+  grid-template-columns: repeat(var(--grid-columns), minmax(var(--day-column-min-width), 1fr));
+  min-width: calc(var(--grid-columns) * var(--day-column-min-width));
+  grid-auto-rows: 28px;
+  gap: 2px 0;
+  min-height: 0;
   overflow: hidden;
   background: var(--color-background-alt);
   border-bottom: 1px solid var(--color-border);