CellMove Event 151
Applies To: Grid
Description
If enabled, this event is reported when the user attempts to position the cursor over a cell in a Grid by clicking the left mouse button or by pressing a cursor movement key. The purpose of this event is to allow an application to perform some action prior to the user entering a cell, to inhibit entry to a cell, or to deny exit from the current cell.
The default action is to position the user on the new cell. This action can be prevented by returning a 0 from the callback function attached to the event.
The event message reported as the result of ⎕DQ, or supplied as the right argument to your callback function, is an 8 element vector as follows :
[1] |
Object | ref or character vector |
[2] |
Event | 'CellMove' or 151 |
[3] |
New cell row | integer |
[4] |
New cell column | integer |
[5] |
Scroll flag | 0 or 1 |
[6] |
Selection flag | 0, 1 or 2 |
[7] |
Mouse flag | 0 or 1 |
[8] |
Changed flag | 0 or 1 (relates to current cell) |
[9] |
New value | new value of current cell or ⍬ |
The 5th element of the event message is 1 if switching to the new cell would cause the Grid to scroll.
The 6th element of the event message is 1 if the user is moving to the new cell by extending the selection. It is 2 if the user selects an entire row or column (by clicking on a title), which moves the current cell to the first one in the selection.
The 7th element of the event message is 1 if the mouse is used to switch to a new cell.
The 8th element of the event message is 1 if the user is attempting to move to the new cell from another cell in the Grid having typed in (as if to alter) the current cell.
The 9th element of the event message is the intended new value in the current cell or ⍬ (zilde) if Changed flag is 0.
The CellMove event may be used to validate and refuse changes as the user navigates between cells. See also CellChange.
An application can position the user on a particular cell in a Grid by calling CellMove as a method. If so, the argument need contain only the New cell row and New cell column parameters.