RowFocusChanging event
Description
Occurs when the current row is about to change in the DataWindow.
(The current row of the DataWindow is not necessarily the same as
the current row in the database.)
The RowFocusChanging event occurs just before the RowFocusChanged event.
PowerBuilder event information
Event ID: pbm_dwnrowchanging
|
Argument |
Description |
|---|---|
|
currentrow |
Long by value. The number of the row |
|
newrow |
Long by value. The number of the row |
Web DataWindow client control event information
Event name: RowFocusChanging
|
Argument |
Description |
|---|---|
|
currentRow |
Number. The number of the row that is |
|
newRow |
Number. The number of the row that is |
Web ActiveX event information
Event name: beforeRowFocusChange
|
Argument |
Description |
|---|---|
|
CurrentRow |
Number. The number of the row that is |
|
NewRow |
Number. The number of the row that is |
Return Values
Set the return code to affect the outcome of the event:
-
0 Continue processing
(setting the current row) -
1 Prevent the current row from changing
For information on setting the return code in a particular
environment, see “About return values for
DataWindow events”.
Usage
Typically the RowFocusChanging event is coded to respond to
a mouse click or keyboard action that would change the current row
in the DataWindow object. The following methods can also trigger
the RowFocusChanging event, as well as the RowFocusChanged and ItemFocusChanged
events, when the action changes the current row:
-
SetRow
-
Retrieve
-
RowsCopy
-
RowsMove
-
DeleteRow
-
RowsDiscard
In these cases, the RowFocusChanging event script can prevent
the changing of the DataWindow object’s current row only.
The script cannot prevent the data from being changed (for example,
the rows still get moved).
When you use the ScrollToRow method to
change focus, the RowFocusChanging event is triggered before the
scroll occurs, and the RowFocusChanged event is triggered after
the scroll occurs.
In a tabular DataWindow, if the user clicks to change rows,
the row focus does not change, and the row and DataWindow do not
scroll. You can still scroll programmatically or by using the scroll
bar.
In a read-only DataWindow, when you click on any column that
is not in the current row, the RowFocusChanging and RowFocusChanged
events fire, but the current column is not changed—the
current column remains at 0, since no column can have focus. DataWindows
are read-only if updates are not allowed, all tab orders are set
to 0, or all tab columns are protected.
However, if focus is on an editable column in an updatable
DataWindow (a DataWindow that has one or more editable columns),
the row focus events do not fire when you click on a protected column
or on a column whose tab order is 0. The focus remains on the current,
editable column.
If focus moves off an editable column in an updatable DataWindow,
the DataWindow switches to read-only mode. This can happen when
the last row in the DataWindow does not have an editable column.
In this case, tabbing off the last editable column causes the row
focus to move to the row following the row with the last editable
column. The DataWindow then remains in read-only mode until focus
is given to an editable column.
Examples
This example displays a message alerting you that
changes have been made in the window dw_detail which will
be lost if the row focus is changed to the window dw_master.
|
1 |
IF dw_detail.DeletedCount() > 0 OR & <br> dw_detail.ModifiedCount() > 0 THEN |
|
1 |
MessageBox("dw_master", "Changes will be lost &<br> in Detail") |
|
1 |
ELSE |
|
1 |
RETURN 0 |
|
1 |
END IF |