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A property of the SYSTEM built-in variable that defers the resizing and/or movement of controls until the end of the ACCEPT loop or SYSTEM{PROP:DeferMove} is reset to zero (0). This disables the immediate effect of all assignments to position and size properties, enabling the library to perform all moves at once (which eliminates temporarily overlapping controls). The absolute value of the number assigned to SYSTEM{PROP:DeferMove} defines the number of deferred moves for which space is pre-allocated (automatically expanded when necessary, but less efficient and may fail). Assigning a positive number automatically resets PROP:DeferMove to zero at the next ACCEPT, while a negative number leaves it set until explicitly reset to zero (0).

In multi-threaded applications, the setting of SYSTEM{PROP:DeferMove} to a non-zero value initiates the deferred move for the current thread only.

PROP:DeferMove is ignored if PROP:LazyDisplay is set to zero (0).

Example:

WinView WINDOW('View'),AT(0,0,320,200),MDI,MAX,HVSCROLL
        IMAGE(),AT(0,0,,),USE(?Image)
        BUTTON('New Picture'),AT(160,180,60,20),USE(?NewPic)
        BUTTON('Close'),AT(80,180,60,20),USE(?Close)
       END
FileName    STRING(64)                 !Filename variable
ImageWidth  SHORT
ImageHeight SHORT
  CODE
  OPEN(WinView)
  DISABLE(?LastPic)
  IF NOT FILEDIALOG('Choose File to View',FileName,'BitMap|*.BMP|PCX|*.PCX',0)
   RETURN                        !Return if no file chosen
  END
  ?Image{PROP:Text} = FileName
  ACCEPT
   CASE ACCEPTED()
   OF ?NewPic
    IF NOT FILEDIALOG('Choose File to View',FileName,'BitMap|*.BMP|PCX|*.PCX',0)
     BREAK                       !Return if no file chosen
    END
    ?Image{PROP:Text} = FileName
    SYSTEM{PROP:DeferMove} = 4               !Defer move and resize 
    ImageWidth = ?Image{PROP:Width}          !1 move
    ImageHeight = ?Image{PROP:Height}        !2 moves
    IF ImageWidth > 320
     ?Image{PROP:Width} = 320
     ?Image{PROP:XPos} = 0
    ELSE
     ?Image{PROP:XPos} = (320 - ImageWidth) / 2    !Center horizontally
    END
    IF ImageHeight > 180
     ?Image{PROP:Height} = 180
     ?Image{PROP:YPos} = 0
    ELSE
     ?Image{PROP:YPos} = (180 - ImageHeight) / 2   !Center vertically 
    END
   OF ?Close
    BREAK
   END 
  END             !Moves and resizing happens at the end of the ACCEPT loop