Drop position

version 2004.2 (Modified)

Drop position {(columnNumber)} Number

The Drop position command can be used to find out the location, in a "complex" destination object, where an object has been (dragged and) dropped.

Typically, you will use Drop position when handling a drag and drop event that occurred over an array, a list box or a hierarchical list.

• If the destination object is an array, the command returns an element number.

• If the destination object is a list box, the command returns a row number. In this case, the command also returns the column number where the drop took place in the optional columnNumber parameter.

• If the destination object is a hierarchical list, the command returns an item position.

In all cases, the command may return -1 if the source object has been dropped beyond the last element or the last item of the destination object.

If you call Drop position when handling an event that is not a drag-and-drop event and that occurred over an array or a hierarchical list, the command returns -1.

Important: A form object accepts dropped data if its Droppable property has been selected. Also, its object method must be activated for On Drag Over and/or On Drop, in order to process these events.

1. See the examples for the DRAG AND DROP PROPERTIES command.

2. In the following example, a list of amounts paid must be broken down per month and per person. This is carried out by drag and drop from a scrollable area:

The list box object method contains the following code:

   Case of 
      :(Form event=On Drag Over)
         DRAG AND DROP PROPERTIES($source;$arrayrow;$processnum)
         If ($source=Get pointer("SA1")) `If the drop does come from the scrollable area
            $0:=0
         Else
            $0:=-1 `The drop is refused
         End if
      :(Form event=On Drop)
         DRAG AND DROP PROPERTIES($source;$arrayrow;$processnum)
         $rownum:=Drop position($colnum)
         If ($colnum=1)
            BEEP
         Else 
            Case of  `Adding of dropped values
               : ($colnum=2)
                  John{$rownum}:=John{$rownum}+SA1{$arrayrow}
               : ($colnum=3)
                  Mark{$rownum}:=Mark{$rownum}+SA1{$arrayrow}
               : ($colnum=4)
                  Peter{$rownum}:=Peter{$rownum}+SA1{$arrayrow}
            End case 
            DELETE ELEMENT(SA1;$arrayrow) `Updating of area
         End if 
   End case 

Drag and Drop, DRAG AND DROP PROPERTIES.