LockColumns Method 227

Applies To: Grid

Description

This method is used to lock one or more columns of a Grid object. However, LockColumns is not supported in combination with hierarchical column titles as specified by the ColTitleDepth property.

The argument to LockColumns is a 1 or 2-element vector as follows.

[1]	Column(s)	integer scalar, vector or matrix
[2]	Lock flag	0 or 1

Column(s) may be a scalar or a vector specifying the column or columns to be locked or unlocked. Alternatively, it may be a matrix whose first row specifies the columns to be locked and whose second row specifies where they are to be locked.

If the Lock flag is 1, the corresponding columns are locked. This is the default and may be omitted. If the Lock flag is 0, the corresponding columns are unlocked

Examples

      F.G.LockColumns 3         ⍝Lock 3rd column
      F.G.LockColumns 3 0       ⍝Unlock 3rd column
      F.G.LockColumns (4 5)     ⍝Lock 4th & 5th cols
      F.G.LockColumns (2 1⍴8 4) ⍝Lock 8 at 4
      F.G.LockColumns 3         ⍝Lock 3rd column
      F.G.LockColumns 3 0       ⍝Unlock 3rd column
      F.G.LockColumns (4 5)     ⍝Lock 4th & 5th cols
      F.G.LockColumns (2 1⍴8 4) ⍝Lock 8 at 4

The result is an integer matrix containing the indices of all locked columns and the positions at which they are currently locked.

The expression:

      F.G.LockColumns ⊂⍬

may therefore be used to obtain the indices of the locked columns, and:

      F.G.LockColumns(F.G.LockColumns ⊂⍬) 0

unlocks all currently locked columns.

Locks are additive. If column 4 is locked, locking column 5 results in both columns 4 and 5 being locked.

A locked column remains fixed in position and does not scroll sideways. The user may enter and edit cells in a locked column in the normal way, but the behaviour of the various cell movement keys (Tab, left and right cursor, and so forth) differs when a locked column is encountered. As a general rule, if a keystroke attempts to move the cursor into a locked column from an adjacent column, and the adjacent column has been scrolled, it is unscrolled and the cursor remains in the (new) column adjacent to the fixed column. If not, the cursor moves into the locked column.

When you lock a column, the position you specify for it to be locked at is a position in the data and not the physical position of the column as displayed in the Grid. The physical column in the Grid depends upon the value of the Index property at the time it was locked.

If C is the value specified for where a given column is to be locked, the value of the physical column P at which it will be displayed in the Grid named GRID is:

      P←C-(2⊃GRID ⎕WG 'Index')-⎕IO

Furthermore, the position of a locked column given by the result of the LockColumns method changes (with the Index property) as the Grid is scrolled.