Improves all-day event drag and drop

Refactors all-day event drag and drop handling for improved accuracy and performance.

Introduces a shared `ColumnDetectionUtils` for consistent column detection.

Simplifies all-day conversion during drag, placing events in row 1 and calculating the column from the target date.

Implements differential updates during drag end, updating only changed events for smoother transitions.

src/managers/AllDayManager.ts

@@ -4,12 +4,14 @@ import { eventBus } from '../core/EventBus';
 import { ALL_DAY_CONSTANTS } from '../core/CalendarConfig';
 import { AllDayEventRenderer } from '../renderers/AllDayEventRenderer';
 import { AllDayLayoutEngine } from '../utils/AllDayLayoutEngine';
+import { ColumnDetectionUtils } from '../utils/ColumnDetectionUtils';
 import { CalendarEvent } from '../types/CalendarTypes';
 import {
   DragMouseEnterHeaderEventPayload,
   DragStartEventPayload,
   DragMoveEventPayload,
-  DragEndEventPayload
+  DragEndEventPayload,
+  DragColumnChangeEventPayload
 } from '../types/EventTypes';
 import { DragOffset, MousePosition } from '../types/DragDropTypes';
 
@@ -20,6 +22,11 @@ import { DragOffset, MousePosition } from '../types/DragDropTypes';
 export class AllDayManager {
   private allDayEventRenderer: AllDayEventRenderer;
   private layoutEngine: AllDayLayoutEngine | null = null;
+  
+  // State tracking for differential updates
+  private currentLayouts: Map<string, string> = new Map();
+  private currentAllDayEvents: CalendarEvent[] = [];
+  private currentWeekDates: string[] = [];
 
   constructor() {
     this.allDayEventRenderer = new AllDayEventRenderer();
@@ -53,10 +60,6 @@ export class AllDayManager {
         originalElementId: originalElement?.dataset?.eventId
       });
 
-      if (cloneElement && cloneElement.classList.contains('all-day-style')) {
-        this.handleConvertFromAllDay(cloneElement);
-      }
-
       this.checkAndAnimateAllDayHeight();
     });
 
@@ -73,17 +76,26 @@ export class AllDayManager {
       this.handleDragStart(draggedElement, eventId || '', mouseOffset);
     });
 
-    eventBus.on('drag:move', (event) => {
+    eventBus.on('drag:column-change', (event) => {
-      const { draggedElement, mousePosition } = (event as CustomEvent<DragMoveEventPayload>).detail;
+      const { draggedElement, mousePosition } = (event as CustomEvent<DragColumnChangeEventPayload>).detail;
-
+     
-      // Only handle for all-day events - check if original element is all-day
-      const isAllDayEvent = draggedElement.closest('swp-allday-container');
-      if (!isAllDayEvent) return;
 
+      // Check if there's an all-day clone for this event
       const eventId = draggedElement.dataset.eventId;
-      const dragClone = document.querySelector(`swp-allday-container swp-event[data-event-id="clone-${eventId}"]`);
+      const dragClone = document.querySelector(`swp-allday-container swp-event[data-event-id="clone-${eventId}"]`) as HTMLElement;
+      
+       if (!dragClone.hasAttribute('data-allday')) {
+        return; 
+      }
+
+
+      // If we find an all-day clone, handle the drag move
       if (dragClone) {
-        this.handleDragMove(dragClone as HTMLElement, mousePosition);
+        console.log('🔄 AllDayManager: Found all-day clone, handling drag:column-change', {
+          eventId,
+          cloneId: dragClone.dataset.eventId
+        });
+        this.handleColumnChange(dragClone, mousePosition);
       }
     });
 
@@ -259,6 +271,42 @@ export class AllDayManager {
     });
   }
 
+  /**
+   * Store current layouts from DOM for comparison
+   */
+  private storeCurrentLayouts(): void {
+    this.currentLayouts.clear();
+    const container = this.getAllDayContainer();
+    if (!container) return;
+    
+    container.querySelectorAll('swp-event').forEach(element => {
+      const htmlElement = element as HTMLElement;
+      const eventId = htmlElement.dataset.eventId;
+      const gridArea = htmlElement.style.gridArea;
+      if (eventId && gridArea) {
+        this.currentLayouts.set(eventId, gridArea);
+      }
+    });
+    
+    console.log('📋 AllDayManager: Stored current layouts', {
+      count: this.currentLayouts.size,
+      layouts: Array.from(this.currentLayouts.entries())
+    });
+  }
+
+  /**
+   * Set current events and week dates (called by EventRendererManager)
+   */
+  public setCurrentEvents(events: CalendarEvent[], weekDates: string[]): void {
+    this.currentAllDayEvents = events;
+    this.currentWeekDates = weekDates;
+    
+    console.log('📝 AllDayManager: Set current events', {
+      eventCount: events.length,
+      weekDatesCount: weekDates.length
+    });
+  }
+
   /**
    * Calculate layout for ALL all-day events using AllDayLayoutEngine
    * This is the correct method that processes all events together for proper overlap detection
@@ -276,6 +324,10 @@ export class AllDayManager {
       weekDates
     });
     
+    // Store current state
+    this.currentAllDayEvents = events;
+    this.currentWeekDates = weekDates;
+    
     // Initialize layout engine with provided week dates
     this.layoutEngine = new AllDayLayoutEngine(weekDates);
     
@@ -313,95 +365,37 @@ export class AllDayManager {
 
 
   /**
-   * Handle conversion of timed event to all-day event using CSS styling
+   * Handle conversion of timed event to all-day event - SIMPLIFIED
+   * During drag: Place in row 1 only, calculate column from targetDate
    */
   private handleConvertToAllDay(targetDate: string, cloneElement: HTMLElement): void {
-    console.log('🔄 AllDayManager: Converting to all-day using AllDayLayoutEngine', {
+    console.log('🔄 AllDayManager: Converting to all-day (row 1 only during drag)', {
       eventId: cloneElement.dataset.eventId,
       targetDate
     });
 
     // Get all-day container, request creation if needed
     let allDayContainer = this.getAllDayContainer();
-    if (!allDayContainer) {
-      console.log('🔄 AllDayManager: All-day container not found, requesting creation...');
-      // Request HeaderManager to create container
-      eventBus.emit('header:ensure-allday-container');
 
-      // Try again after request
+    // Calculate target column from targetDate using ColumnDetectionUtils
-      allDayContainer = this.getAllDayContainer();
+    const targetColumn = ColumnDetectionUtils.getColumnIndexFromDate(targetDate);
-      if (!allDayContainer) {
-        console.error('All-day container still not found after creation request');
-        return;
-      }
-    }
 
-    // Create mock event for layout calculation
+    cloneElement.removeAttribute('style');
-    const mockEvent: CalendarEvent = {
-      id: cloneElement.dataset.eventId || '',
-      title: cloneElement.dataset.title || '',
-      start: new Date(targetDate),
-      end: new Date(targetDate),
-      type: 'work',
-      allDay: true,
-      syncStatus: 'synced'
-    };
-
-    // Get existing all-day events from EventManager
-    const existingEvents = this.getExistingAllDayEvents();
-    
-    // Add the new drag event to the array
-    const allEvents = [...existingEvents, mockEvent];
-    
-    // Get actual visible dates from DOM headers (same as EventRendererManager does)
-    const weekDates = this.getVisibleDatesFromDOM();
-    
-    // Calculate layout for all events including the new one
-    const layouts = this.calculateAllDayEventsLayout(allEvents, weekDates);
-    const layout = layouts.get(mockEvent.id);
-    
-    if (!layout) {
-      console.error('AllDayManager: No layout found for drag event', mockEvent.id);
-      return;
-    }
-
-    // Set all properties BEFORE adding to DOM
     cloneElement.classList.add('all-day-style');
-    cloneElement.style.gridColumn = layout.startColumn.toString();
+    cloneElement.style.gridRow = '1';
-    cloneElement.style.gridRow = layout.row.toString();
+    cloneElement.style.gridColumn = targetColumn.toString();
-    cloneElement.dataset.allDayDate = targetDate;
+    cloneElement.dataset.allday = 'true'; // Set the all-day attribute for filtering
-    cloneElement.style.display = '';
 
-    // NOW add to container (after all positioning is calculated)
+    // Add to container
-    allDayContainer.appendChild(cloneElement);
+    allDayContainer?.appendChild(cloneElement);
 
-    console.log('✅ AllDayManager: Converted to all-day style using AllDayLayoutEngine', {
+    console.log('✅ AllDayManager: Converted to all-day style (simple row 1)', {
       eventId: cloneElement.dataset.eventId,
-      gridColumn: layout.startColumn,
+      gridColumn: targetColumn,
-      gridRow: layout.row
+      gridRow: 1
     });
   }
 
-  /**
-   * Handle conversion from all-day back to timed event
-   */
-  private handleConvertFromAllDay(cloneElement: HTMLElement): void {
-    console.log('🔄 AllDayManager: Converting from all-day back to timed', {
-      eventId: cloneElement.dataset.eventId
-    });
-
-    // Remove all-day CSS class
-    cloneElement.classList.remove('all-day-style');
-
-    // Reset grid positioning
-    cloneElement.style.gridColumn = '';
-    cloneElement.style.gridRow = '';
-
-    // Remove all-day date attribute
-    delete cloneElement.dataset.allDayDate;
-
-    console.log('✅ AllDayManager: Converted from all-day back to timed');
-  }
 
   /**
    * Handle drag start for all-day events
@@ -439,49 +433,114 @@ export class AllDayManager {
   }
 
   /**
-   * Handle drag move for all-day events
+   * Handle drag move for all-day events - SPECIALIZED FOR ALL-DAY CONTAINER
    */
-  private handleDragMove(dragClone: HTMLElement, mousePosition: MousePosition): void {
+  private handleColumnChange(dragClone: HTMLElement, mousePosition: MousePosition): void {
-    // Calculate grid column based on mouse position
+    // Get the all-day container to understand its grid structure
-    const dayHeaders = document.querySelectorAll('swp-day-header');
+    const allDayContainer = this.getAllDayContainer();
-    let targetColumn = 1;
+    if (!allDayContainer) return;
 
-    dayHeaders.forEach((header, index) => {
+    // Calculate target column using ColumnDetectionUtils
-      const rect = header.getBoundingClientRect();
+    const targetColumn = ColumnDetectionUtils.getColumnIndexFromX(mousePosition.x);
-      if (mousePosition.x >= rect.left && mousePosition.x <= rect.right) {
-        targetColumn = index + 1;
-      }
-    });
 
-    // Update clone position
+    // Update clone position - ALWAYS keep in row 1 during drag
+    // Use simple grid positioning that matches all-day container structure
     dragClone.style.gridColumn = targetColumn.toString();
+    dragClone.style.gridRow = '1'; // Force row 1 during drag
+    dragClone.style.gridArea = `1 / ${targetColumn} / 2 / ${targetColumn + 1}`;
 
-    console.log('🔄 AllDayManager: Updated drag clone position', {
+    console.log('🔄 AllDayManager: Updated all-day drag clone position', {
       eventId: dragClone.dataset.eventId,
       targetColumn,
+      gridRow: 1,
+      gridArea: dragClone.style.gridArea,
       mouseX: mousePosition.x
     });
   }
 
   /**
-   * Handle drag end for all-day events
+   * Handle drag end for all-day events - WITH DIFFERENTIAL UPDATES
    */
   private handleDragEnd(originalElement: HTMLElement, dragClone: HTMLElement, finalPosition: { column: string; y: number }): void {
-    // Normalize clone
+    console.log('🎯 AllDayManager: Starting drag end with differential updates', {
+      eventId: dragClone.dataset.eventId,
+      finalColumn: finalPosition.column
+    });
+
+    // 1. Store current layouts BEFORE any changes
+    this.storeCurrentLayouts();
+
+    // 2. Normalize clone ID
     const cloneId = dragClone.dataset.eventId;
     if (cloneId?.startsWith('clone-')) {
       dragClone.dataset.eventId = cloneId.replace('clone-', '');
     }
 
-    // Remove dragging styles
+    // 3. Create temporary array with existing events + the dropped event
+    const droppedEventId = dragClone.dataset.eventId || '';
+    const droppedEventDate = dragClone.dataset.allDayDate || finalPosition.column;
+    
+    const droppedEvent: CalendarEvent = {
+      id: droppedEventId,
+      title: dragClone.dataset.title || dragClone.textContent || '',
+      start: new Date(droppedEventDate),
+      end: new Date(droppedEventDate),
+      type: 'work',
+      allDay: true,
+      syncStatus: 'synced'
+    };
+
+    // Use current events + dropped event for calculation
+    const tempEvents = [...this.currentAllDayEvents, droppedEvent];
+
+    // 4. Calculate new layouts for ALL events
+    const newLayouts = this.calculateAllDayEventsLayout(tempEvents, this.currentWeekDates);
+
+    // 5. Apply differential updates - only update events that changed
+    let changedCount = 0;
+    newLayouts.forEach((layout, eventId) => {
+      const oldGridArea = this.currentLayouts.get(eventId);
+      const newGridArea = layout.gridArea;
+
+      if (oldGridArea !== newGridArea) {
+        changedCount++;
+        const element = document.querySelector(`[data-event-id="${eventId}"]`) as HTMLElement;
+        if (element) {
+          console.log('🔄 AllDayManager: Updating event position', {
+            eventId,
+            oldGridArea,
+            newGridArea
+          });
+
+          // Add transition class for smooth animation
+          element.classList.add('transitioning');
+          element.style.gridArea = newGridArea;
+          element.style.gridRow = layout.row.toString();
+          element.style.gridColumn = `${layout.startColumn} / ${layout.endColumn + 1}`;
+
+          // Remove transition class after animation
+          setTimeout(() => element.classList.remove('transitioning'), 200);
+        }
+      }
+    });
+
+    // 6. Clean up drag styles from the dropped clone
     dragClone.classList.remove('dragging');
     dragClone.style.zIndex = '';
     dragClone.style.cursor = '';
     dragClone.style.opacity = '';
 
-    console.log('✅ AllDayManager: Completed drag operation for all-day event', {
+    // 7. Restore original element opacity
-      eventId: dragClone.dataset.eventId,
+    originalElement.style.opacity = '';
-      finalColumn: dragClone.style.gridColumn
+
+    // 8. Check if height adjustment is needed
+    this.checkAndAnimateAllDayHeight();
+
+    console.log('✅ AllDayManager: Completed differential drag end', {
+      eventId: droppedEventId,
+      totalEvents: newLayouts.size,
+      changedEvents: changedCount,
+      finalGridArea: newLayouts.get(droppedEventId)?.gridArea
     });
   }
 

src/managers/DragDropManager.ts

@@ -6,12 +6,14 @@
 import { IEventBus } from '../types/CalendarTypes';
 import { calendarConfig } from '../core/CalendarConfig';
 import { PositionUtils } from '../utils/PositionUtils';
+import { ColumnDetectionUtils } from '../utils/ColumnDetectionUtils';
 import {
   DragStartEventPayload,
   DragMoveEventPayload,
   DragEndEventPayload,
   DragMouseEnterHeaderEventPayload,
-  DragMouseLeaveHeaderEventPayload
+  DragMouseLeaveHeaderEventPayload,
+  DragColumnChangeEventPayload
 } from '../types/EventTypes';
 
 interface CachedElements {
@@ -25,11 +27,6 @@ interface Position {
   y: number;
 }
 
-interface ColumnBounds {
-  date: string;
-  left: number;
-  right: number;
-}
 
 export class DragDropManager {
   private eventBus: IEventBus;
@@ -59,8 +56,6 @@ export class DragDropManager {
     lastColumnDate: null
   };
 
-  // Column bounds cache for coordinate-based column detection
-  private columnBoundsCache: ColumnBounds[] = [];
 
 
   // Auto-scroll properties
@@ -120,16 +115,16 @@ export class DragDropManager {
     }
 
     // Initialize column bounds cache
-    this.updateColumnBoundsCache();
+    ColumnDetectionUtils.updateColumnBoundsCache();
 
     // Listen to resize events to update cache
     window.addEventListener('resize', () => {
-      this.updateColumnBoundsCache();
+      ColumnDetectionUtils.updateColumnBoundsCache();
     });
 
     // Listen to navigation events to update cache
     this.eventBus.on('navigation:completed', () => {
-      this.updateColumnBoundsCache();
+      ColumnDetectionUtils.updateColumnBoundsCache();
     });
 
   }
@@ -247,12 +242,13 @@ export class DragDropManager {
           const previousColumn = this.currentColumn;
           this.currentColumn = newColumn;
 
-          this.eventBus.emit('drag:column-change', {
+          const dragColumnChangePayload: DragColumnChangeEventPayload = {
             draggedElement: this.draggedElement,
             previousColumn,
             newColumn,
             mousePosition: currentPosition
-          });
+          };
+          this.eventBus.emit('drag:column-change', dragColumnChangePayload);
         }
       }
     }
@@ -377,58 +373,13 @@ export class DragDropManager {
     return Math.max(0, snappedY);
   }
 
-  /**
-   * Update column bounds cache for coordinate-based column detection
-   */
-  private updateColumnBoundsCache(): void {
-    // Reset cache
-    this.columnBoundsCache = [];
-
-    // Find alle kolonner
-    const columns = document.querySelectorAll('swp-day-column');
-
-    // Cache hver kolonnes x-grænser
-    columns.forEach(column => {
-      const rect = column.getBoundingClientRect();
-      const date = (column as HTMLElement).dataset.date;
-
-      if (date) {
-        this.columnBoundsCache.push({
-          date,
-          left: rect.left,
-          right: rect.right
-        });
-      }
-    });
-
-    // Sorter efter x-position (fra venstre til højre)
-    this.columnBoundsCache.sort((a, b) => a.left - b.left);
-
-  }
-
-  /**
-   * Get column date from X coordinate using cached bounds
-   */
-  private getColumnDateFromX(x: number): string | null {
-    // Opdater cache hvis tom
-    if (this.columnBoundsCache.length === 0) {
-      this.updateColumnBoundsCache();
-    }
-
-    // Find den kolonne hvor x-koordinaten er indenfor grænserne
-    const column = this.columnBoundsCache.find(col =>
-      x >= col.left && x <= col.right
-    );
-
-    return column ? column.date : null;
-  }
 
   /**
    * Coordinate-based column detection (replaces DOM traversal)
    */
   private detectColumn(mouseX: number, mouseY: number): string | null {
     // Brug den koordinatbaserede metode direkte
-    const columnDate = this.getColumnDateFromX(mouseX);
+    const columnDate = ColumnDetectionUtils.getColumnDateFromX(mouseX);
 
     // Opdater stadig den eksisterende cache hvis vi finder en kolonne
     if (columnDate && columnDate !== this.cachedElements.lastColumnDate) {
@@ -610,7 +561,7 @@ export class DragDropManager {
       this.isInHeader = true;
 
       // Calculate target date using existing method
-      const targetDate = this.getColumnDateFromX(event.clientX);
+      const targetDate = ColumnDetectionUtils.getColumnDateFromX(event.clientX);
 
       if (targetDate) {
         console.log('🎯 DragDropManager: Emitting drag:mouseenter-header', { targetDate });
@@ -636,7 +587,7 @@ export class DragDropManager {
       console.log('🚪 DragDropManager: Emitting drag:mouseleave-header');
 
       // Calculate target date using existing method
-      const targetDate = this.getColumnDateFromX(event.clientX);
+      const targetDate = ColumnDetectionUtils.getColumnDateFromX(event.clientX);
 
       // Find clone element (if it exists)
       const eventId = this.draggedElement?.dataset.eventId;

src/renderers/EventRendererManager.ts

@@ -8,7 +8,7 @@ import { AllDayManager } from '../managers/AllDayManager';
 import { EventRendererStrategy } from './EventRenderer';
 import { SwpEventElement } from '../elements/SwpEventElement';
 import { AllDayEventRenderer } from './AllDayEventRenderer';
-import { DragStartEventPayload, DragMoveEventPayload, DragEndEventPayload, DragMouseEnterHeaderEventPayload, DragMouseLeaveHeaderEventPayload, HeaderReadyEventPayload } from '../types/EventTypes';
+import { DragStartEventPayload, DragMoveEventPayload, DragEndEventPayload, DragMouseEnterHeaderEventPayload, DragMouseLeaveHeaderEventPayload, DragColumnChangeEventPayload, HeaderReadyEventPayload } from '../types/EventTypes';
 /**
  * EventRenderingService - Render events i DOM med positionering using Strategy Pattern
  * Håndterer event positioning og overlap detection
@@ -190,6 +190,11 @@ export class EventRenderingService {
         // Handle drag move
         this.eventBus.on('drag:move', (event: Event) => {
             const { draggedElement, snappedY, column, mouseOffset } = (event as CustomEvent<DragMoveEventPayload>).detail;
+            
+            // Filter: Only handle events WITHOUT data-allday attribute (normal timed events)
+            if (draggedElement.hasAttribute('data-allday')) {
+                return; // This is an all-day event, let AllDayManager handle it
+            }
             if (this.strategy.handleDragMove && column) {
                 const eventId = draggedElement.dataset.eventId || '';
                 this.strategy.handleDragMove(eventId, snappedY, column, mouseOffset);
@@ -241,7 +246,7 @@ export class EventRenderingService {
 
         // Handle column change
         this.eventBus.on('drag:column-change', (event: Event) => {
-            const { draggedElement, newColumn } = (event as CustomEvent).detail;
+            const { draggedElement, newColumn } = (event as CustomEvent<DragColumnChangeEventPayload>).detail;
             if (this.strategy.handleColumnChange) {
                 const eventId = draggedElement.dataset.eventId || '';
                 this.strategy.handleColumnChange(eventId, newColumn);
@@ -359,6 +364,9 @@ export class EventRenderingService {
             count: weekDates.length
         });
         
+        // Pass current events to AllDayManager for state tracking
+        this.allDayManager.setCurrentEvents(allDayEvents, weekDates);
+        
         // Calculate layout for ALL all-day events together using AllDayLayoutEngine
         const layouts = this.allDayManager.calculateAllDayEventsLayout(allDayEvents, weekDates);
         

src/types/EventTypes.ts

@@ -87,6 +87,14 @@ export interface DragMouseLeaveHeaderEventPayload {
   cloneElement: HTMLElement| null;
 }
 
+// Drag column change event payload
+export interface DragColumnChangeEventPayload {
+  draggedElement: HTMLElement;
+  previousColumn: string | null;
+  newColumn: string;
+  mousePosition: MousePosition;
+}
+
 // Header ready event payload
 export interface HeaderReadyEventPayload {
   headerElement: HTMLElement;

src/utils/ColumnDetectionUtils.ts

@@ -0,0 +1,94 @@
+/**
+ * ColumnDetectionUtils - Shared utility for column detection and caching
+ * Used by both DragDropManager and AllDayManager for consistent column detection
+ */
+
+export interface ColumnBounds {
+  date: string;
+  left: number;
+  right: number;
+}
+
+export class ColumnDetectionUtils {
+  private static columnBoundsCache: ColumnBounds[] = [];
+
+  /**
+   * Update column bounds cache for coordinate-based column detection
+   */
+  public static updateColumnBoundsCache(): void {
+    // Reset cache
+    this.columnBoundsCache = [];
+
+    // Find alle kolonner
+    const columns = document.querySelectorAll('swp-day-column');
+
+    // Cache hver kolonnes x-grænser
+    columns.forEach(column => {
+      const rect = column.getBoundingClientRect();
+      const date = (column as HTMLElement).dataset.date;
+
+      if (date) {
+        this.columnBoundsCache.push({
+          date,
+          left: rect.left,
+          right: rect.right
+        });
+      }
+    });
+
+    // Sorter efter x-position (fra venstre til højre)
+    this.columnBoundsCache.sort((a, b) => a.left - b.left);
+  }
+
+  /**
+   * Get column date from X coordinate using cached bounds
+   */
+  public static getColumnDateFromX(x: number): string | null {
+    // Opdater cache hvis tom
+    if (this.columnBoundsCache.length === 0) {
+      this.updateColumnBoundsCache();
+    }
+
+    // Find den kolonne hvor x-koordinaten er indenfor grænserne
+    const column = this.columnBoundsCache.find(col =>
+      x >= col.left && x <= col.right
+    );
+
+    return column ? column.date : null;
+  }
+
+  /**
+   * Get column index (1-based) from date
+   */
+  public static getColumnIndexFromDate(date: string): number {
+    // Opdater cache hvis tom
+    if (this.columnBoundsCache.length === 0) {
+      this.updateColumnBoundsCache();
+    }
+
+    const columnIndex = this.columnBoundsCache.findIndex(col => col.date === date);
+    return columnIndex >= 0 ? columnIndex + 1 : 1; // 1-based index
+  }
+
+  /**
+   * Get column index from X coordinate
+   */
+  public static getColumnIndexFromX(x: number): number {
+    const date = this.getColumnDateFromX(x);
+    return date ? this.getColumnIndexFromDate(date) : 1;
+  }
+
+  /**
+   * Clear cache (useful for testing or when DOM structure changes)
+   */
+  public static clearCache(): void {
+    this.columnBoundsCache = [];
+  }
+
+  /**
+   * Get current cache for debugging
+   */
+  public static getCache(): ColumnBounds[] {
+    return [...this.columnBoundsCache];
+  }
+}

wwwroot/css/calendar-events-css.css

@@ -125,24 +125,21 @@ swp-resize-handle[data-position="bottom"] {
 }
 
 /* Resize handles controlled by JavaScript - no general hover */
-  
+swp-handle-hitarea {
-  /* Hit area */
+  position: absolute;
-  swp-handle-hitarea {
+  left: -8px;
-    position: absolute;
+  right: -8px;
-    left: -8px;
+  top: -6px;
-    right: -8px;
+  bottom: -6px;
-    top: -6px;
+  cursor: ns-resize;
-    bottom: -6px;
+}
-    cursor: ns-resize;
+
-  }
+swp-handle-hitarea[data-position="top"] {
-  
+  top: 4px;
-  &[data-position="top"] {
+}
-    top: 4px;
+
-  }
+swp-handle-hitarea[data-position="bottom"] {
-  
+  bottom: 4px;
-  &[data-position="bottom"] {
-    bottom: 4px;
-  }
 }
 
 /* Multi-day events */
@@ -250,3 +247,8 @@ swp-event-group swp-event {
   right: 0;
   margin: 0;
 }
+
+/* All-day event transition for smooth repositioning */
+swp-allday-container swp-event.transitioning {
+  transition: grid-area 200ms ease-out, grid-row 200ms ease-out, grid-column 200ms ease-out;
+}