**************************************************
*-- Class:        cbogrddropdown 
*-- ParentClass:  combobox
*-- BaseClass:    combobox
*-- Drop Down List for use in a grid. special navigation key handling
*
Define Class cbogrddropdown As ComboBox


  Height = 21
  SpecialEffect = 1
  Style = 2
  Width = 75
  BorderStyle = 0
  *-- Save original setting of _DBLCLICK...facilitate incremental searching
  nolddblclick = 0
  Name = "cbogrddropdown"

  *-- Set to true when the list is dropped so we know how to handle the cursor keys
  ldroppeddown = .F.

  *-- Save the original value of the combo when it gets focus
  uoldval = .F.

  *-- an array property to hold the rowsource when this is using a rowsourcetype f 5-array
  Dimension acontents[1]


  *-- Handle the cursor keys differently depending on whether or not the combo is dropped down
  Procedure handlekey
    Lparameters nKeyCode
    Local lnMaxRow, llRetVal

    With This
      *** If escape or enter pressed, the list is not dropped down anymore
      If nKeyCode = 27 Or nKeyCode = 13
        .ldroppeddown = .F.
      Endif
      *** If the list is not dropped down, traverse the grid with cursor keys
      If !.ldroppeddown
        With .Parent.Parent
          *** Calculate the maximum number of rows in the grid
          lnMaxRows = Int( ( .Height - .HeaderHeight - ;
            IIF( Inlist( .ScrollBars, 1, 3 ),;
            SYSMETRIC( 8 ), 0 ) ) / .RowHeight )
          *** Move up a row in the grid: up arrow key pressed
          If nKeyCode = 5 Then
            *** If we are sitting on the top row in the visible portion of the grid,
            *** Scroll the grid up a row in case there is a previous record
            If .RelativeRow = 1
              .DoScroll( 0 )
            Endif
            .ActivateCell( .RelativeRow - 1, .ActiveColumn )
            *** Let KeyPress know we have handled the keystroke
            llRetVal = .T.
          Else
            *** Move down a row in the grid if the down arrow key is pressed and the
            *** combo box is closed
            *** If we are sitting on the bottom row in the visible portion of the grid,
            *** Scroll the grid down a row in case there is a next record
            If nKeyCode = 24 Then
              If .RelativeRow >= lnMaxRows
                .DoScroll( 1 )
              Endif
              .ActivateCell( .RelativeRow + 1, .ActiveColumn )
              llRetVal = .T.
            Endif
          Endif
        Endwith
      Endif
    Endwith

    Return llRetVal
  Endproc


  Procedure LostFocus
    *** We now need code to check the version number here because VFP 7
    *** Does not use _DBLCLICK for Incremental Search
    If Version( 5 ) > 699
      _Incseek = This.nolddblclick
    Else
      _Dblclick = This.nolddblclick
    Endif
  Endproc


  Procedure KeyPress
    Lparameters nKeyCode, nShiftAltCtrl
    If This.handlekey( nKeyCode )
      Nodefault
    Endif
  Endproc


  Procedure DropDown
    This.ldroppeddown = .T.
  Endproc


  Procedure Click
    This.ldroppeddown = .F.
  Endproc


  Procedure GotFocus
    With This
      *** Save Original value in case we have to restore it later
      .uoldval = .Value
      *** Facilitate incremental searching in the drop down
      If Version( 5 ) > 699
        *** We are in VFP 7.0 or later
        .nolddblclick = _Incseek
        _Incseek = 1.5
      Else
        .nolddblclick = _Dblclick
        _Dblclick = 1.5
      Endif
    Endwith
  Endproc


  Procedure Init
    If DoDefault()
      This.Setup()
    Endif
  Endproc


  *-- Called from the init() to do any setup work in the combo
  Procedure Setup
  Endproc


Enddefine