/// <summary> /// Handle the DragEnter event for the presentation editor /// </summary> /// <param name="sender">sender</param> /// <param name="e">event args</param> protected override void DragEnter(object sender, DragEventArgs e) { if (!htmlMarshallingTarget.IsEditable) //disable drop operations when not in edit mode. { e.Effect = DragDropEffects.None; return; } DataObjectMeister dataMeister = new DataObjectMeister(e.Data); if (HtmlHandler.IsPasteFromSharedCanvas(dataMeister) && htmlMarshallingTarget.SelectionIsInvalid) { e.Effect = DragDropEffects.None; return; } base.DragEnter(sender, e); }