PRB: Disabled Grid Controls Can Be Selected with Mouse

RESOLUTION

Include code in the AfterRowColChange event to handle cases in which the column is being changed to a disabled column or control. Following are two examples of code to accomplish this.

Example One

The following example demonstrates the simplest case. For this example, assume that column one is always disabled, column two is never disabled, and horizontal scrolling is disabled.

   LPARAMETERS nColIndex

   * LPARAMETERS statement required and inserted by Visual FoxPro

   * Check to see if you're on column one
   IF nColIndex = 1
       * Change the active cell
       WITH This
           .ActivateCell(.RelativeRow, 2)
       ENDWITH
   ENDIF
				

NOTE: This example makes use of the RelativeRow property. Do not use the ActiveRow property; it will not work properly. Note that the ActiveCell method assigns the focus to column two even if column two is disabled or the current control in column two is disabled.

Example Two

The following example is slightly more robust. It can be used on scrollable grids, where the columns or controls may have a variable enabled setting. The code first checks to make sure that the current column is valid. If it is not, it starts moving through the available columns until it finds a valid column for input focus, and then sets the focus. The code wraps from the last column to the first, taking into account that several controls may exist within the column. The code leaves the focus on the current column if no columns are enabled.

   LPARAMETERS nColIndex

   * LPARAMETERS statement required and inserted by Visual FoxPro

   LOCAL iLoop, iMax, lFocusSet

   WITH This && Grid

      * Initialize Loop Variables
      iMax = .ColumnCount
      iLoop = nColIndex + 1

      * Check if current column is valid
      WITH .Columns(nColIndex)
         * Column is valid only if the Column's Enabled Property is True
         * and the CurrentControl's Enabled Property is True

         * Note: The EVAL function (cf. EVALUATE() online help) is used as
         * as an alternative to macro substitution for accessing the
         * column's current control

         lFocusSet=.Enabled .AND. EVAL("." + .CurrentControl + ".Enabled")

      ENDWITH

      * Start at next column (to the right) and cycle through all columns
      * until a valid column is reached or loop returns to current column

      * Note: If the current column is valid, lFocusSet = true and this
      * loop is skipped
      DO WHILE iLoop # nColIndex .AND. .NOT. lFocusSet
         * Wrap to first column if necessary
         IF iLoop > iMax
            iLoop = 1
         ELSE

            WITH .Columns(iLoop)
               * If this column is Valid (same criteria as above)
               IF .Enabled .AND. EVAL("." + .CurrentControl + ".Enabled" )
                  * Set focus to column and end loop
                  .SetFocus
                  lFocusSet = .T.
               ENDIF
            ENDWITH
            * Advance to next column
            iLoop = iLoop + 1
         ENDIF
      ENDDO
   ENDWITH
				

NOTE: This example does not take into account columns or controls within columns that have a When event that returns False.