                                  Two-Object Drag
Ŀ
               App1                   App2                    App3               

                                                               
  (user select)                                                
                                              
                                                               
  WM_BEGINDRAG                                                 
                                              
                                                               
           DrgAllocDraginfo                                     
                                                               
            DrgAddStrHandle                                     
                                                               
            DrgSetDragitem                                      
                                                               
            DrgAddStrHandle                                     
                                                               
            DrgSetDragitem                                      
                                                               
               DrgDrag                                          
                                                               
                       DM_DRAGOVER                             
                                         
                                                               
                                 DrgAccessDraginfo              
                                                               
                                (Target emphasis on)            
                                                               
                         (Verify that drop can be accepted)     
                                                               
                                  DrgFreeDraginfo               
                                                               
                       "DOR_DROP"                              
                                         
                                                               
                      DM_DRAGLEAVE                             
                                         
                                                               
                                (Target emphasis off)           
                                                               
                                         
                                                               
                                   DM_DRAGOVER                  
                  
                                                               
                                                        DrgAccessDraginfo
                                                               
                                                       (Target emphasis on)
                                                               
                                                         DrgFreeDraginfo
                                                               
                                   "DOR_DROP"                   
                  
   (WM_ENDDRAG)                                                
                                              
                                                               
                                     DM_DROP                    
                  
                                                               
                                                        DrgAccessDraginfo
                                                               
                                                      (Target emphasis off)
                                                               
                                                       (Perform operation)
                                                               
                                                         DrgFreeDraginfo
                                                               
                                                       DrgSendTransferMsg
                                                               
                               DM_ENDCONVERSATION               
                  
                  
                                                               
                  
                                                               
           (DrgDrag returns)                                    
                                                               
            DrgFreeDraginfo                                     
                                                               
                                                               
                                                               
