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Q146222: How to Use Grid MouseDown Code to Prevent Row/Partition Resize

Article: Q146222
Product(s): Microsoft FoxPro
Version(s): WINDOWS:3.0,3.0b
Operating System(s): 
Keyword(s): kbcode
Last Modified: 05-FEB-2000

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b 
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SUMMARY
=======

There are no Grid properties that can be used to disable the ability to use the
mouse to resize the Grid HeaderHeight and RowHeight or move the Partition
Slider. However, code can be placed in the user procedure associated with the
Grid MouseDown event to prevent any of the following actions being made with the
mouse:

- Resizing the Grid HeaderHeight

- Resizing the Grid RowHeight

- Moving the Partition Slider

MORE INFORMATION
================

To cause the mouse action to be ignored at certain times, a NODEFAULT is
conditionally executed in the Grid MouseDown code depending on the mouse
coordinates. This effectively prevents access to the three previously listed
properties. The following code example is designed for a grid that can be used
in a form, on a page of a pageframe or within a container, regardless of nesting
level.

Place the following code in the procedure associated with the MouseDown event for
the grid.

  ****** Start of Grid MouseDown

  *************************************************************
  * If the grid is on a form (not in a container or pageframe),
  * this section may be omitted. It iterates through
  * object nesting level for all objects above the grid in the
  * hierarchy and makes necessary adjustments to nXCoord and
  * nYCoord. This allows the NODEFAULT to be called at the appropriate
  * time regardless of whether the grid is in a container, page in
  * a pageframe, or a combination that contains several layers.

  LOCAL cObjlist, nTopTotal, nLeftTotal

  cObjlist = ''
  nLeftTotal = 0
  nTopTotal = 0

  cObjlist = SYS(1272,this)        && Get object hierarchy for grid
  IF TYPE('ThisFormSet') = 'O'     && In a Formset?
    * If so, remove Formset from object list
    cObjlist=SUBSTR(cObjlist,AT('.',cObjlist)+1)
  ENDIF

  * Strip off grid name and replace form name with 'thisform'
  cObjlist='thisform' + SUBSTR(cObjlist,AT('.',cObjlist), ;
    RAT('.',cObjlist) - AT('.',cObjlist))

  IF !'thisform'==(cObjlist)   && Something more than thisform in hierarchy?
    FOR i=1 TO OCCURS('.',cObjlist) && Number of '.'s = depth of hierarchy
      IF TYPE("EVAL(cObjList+'.left')")='N'   && Does Obj have Left property?
        nLeftTotal = nLeftTotal+EVAL(cObjlist+'.left') + ;
          IIF('3.10' $ OS(1) OR 'NT' $ OS(1),1,0)  && Add it in
      ENDIF
      IF TYPE("EVAL(cObjList+'.top')")='N'    && Does Obj have Top property?
        nTopTotal=nTopTotal+EVAL(cObjlist+'.top')  && Add it in
      ENDIF
      IF EVAL(cObjlist+'.baseclass')='PageFrame' && Is object a PageFrame?
        IF EVAL(cObjlist+'.tabs')=.T. && Does PageFrame have Tabs?
          nTopTotal=nTopTotal+24 + ;
            IIF('3.10' $ OS(1) OR 'NT' $ OS(1),2,0)   && Add in Tab height
        ELSE
          nTopTotal=nTopTotal + ;
            EVAL(cObjlist+'.borderwidth') + ;
            IIF(EVAL(cObjlist+'.SpecialEffect')<2,1,0)
          nLeftTotal=nLeftTotal+EVAL(cObjlist+'.borderwidth')
        ENDIF
        nLeftTotal=nLeftTotal+1+ IIF('3.10' $OS(1) OR 'NT' $ OS(1),1,0)
      ENDIF
      * Pare last object from list
      cObjlist=SUBSTR(cObjlist,1,RAT('.',cObjlist)-1)
    ENDFOR
  ENDIF

  nXCoord=nXCoord-nLeftTotal   && Compensate nX- and nYCoord for top and left
  nYCoord=nYCoord-nTopTotal    && of all containers that hold the Grid

  *
  * End of section to omit if grid is directly on form
  ****************************************************

WITH this

    * Each of these checks the position of the mouse when the MouseDown
    * is called. If the position is where the click should be ignored,
    * NODEFAULT is issued.

    * This makes rows not resizable

    IF nXCoord < .partition + .Left + 20 AND ;
        nYCoord > .Top + .HeaderHeight + .RowHeight - 5 AND ;
        nYCoord < .Top + .HeaderHeight + .RowHeight + 7
      NODEFAULT
    ENDIF

    * This makes header not resizable

    IF nXCoord < .partition + .Left + 20 AND ;
        nYCoord > .Top + .HeaderHeight - 5 AND ;
        nYCoord < .Top + .HeaderHeight + 7
      NODEFAULT
    ENDIF

    * This makes partition not moveable

    IF MOD(.ScrollBars,2) = 1       && Check for horizontal scrollbar
      IF nXCoord < .partition + .Left + 6 AND ;
      nXCoord >= .partition + .Left AND ;
        nYCoord > .Top + .Height - 19
        NODEFAULT
      ENDIF
    ENDIF

  ENDWITH

Notes
-----

There are 12 x 20 pixel areas where the pointer changes to a two-headed up/down
arrow and the HeaderHeight or RowHeight may be resized. For the HeaderHeight,
this is at the lower edge of the Header on the left side of the grid. For the
RowHeight, this is at the lower edge of the first row of data on the left side
of the grid. Likewise, there is a 19 x 6 pixel area where the pointer changes to
a two-headed left/right arrow and the Partition Slider may be moved. This is the
small black rectangle to the left of the grid's horizontal scroll bar. Although
the pointer will still change when moved over these areas when you use the code
example, you will not be able to make adjustments.

There are slight differences between the calculation of the location of objects
placed within pageframe and container objects in Windows 95, Windows NT, and
Windows 3.1x. The following code conditionally makes these adjustments depending
on the operating system:

     IIF('3.10' $ OS(1) OR 'NT' $ OS(1),1,0)

Additional query words: VFoxWin

======================================================================
Keywords          : kbcode 
Technology        : kbVFPsearch kbAudDeveloper kbVFP300 kbVFP300b
Version           : WINDOWS:3.0,3.0b

=============================================================================

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