Hi there,
I'm running into a problem with TMaskEdit (I'm trying to maintain maskedit..pp)
Desired behaviour (as in Delphi):
When user leaves the control and validation failes (and the according exception is raised), two things must happen:
1. the control must get focus again
2. while resetting the focus to the control the value of FTextOnEnter must _not_ be updated (so that Reset resets the control in a state wher no validation is performed upon lossing focus)
I tried to achieve this using a boolean FValidationFailed, set in DoExit, and examine this in DoEnter (where FTextOnEnter is set).
See the code below (my working copy)
procedure TCustomMaskEdit.DoEnter;
begin
inherited DoEnter;
if isMasked then
begin
debugln('TCustomMaskEdit.DoEnter: FValidationFailed =
',DbgS(FValidationFailed));
FCursorPos := GetSelStart;
//Only save FTextOnEnter if validation did not fail in last DoExit
that occurred
if not FValidationFailed then
FTextOnEnter := Inherited Text
else
FValidationFailed := False;
<snipped irrelevant code>
end;
procedure TCustomMaskEdit.DoExit;
begin
debugln('TCustomMaskEdit.DoExit: FValidationFailed =
',DbgS(FValidationFailed));
//First give OnExit a change to prevent a EDBEditError
inherited DoExit;
{$IFNDEF MASKEDIT_NOVALIDATEONEXIT}
//Do not validate if FValidationFailed, or risk raising an exception
while the previous exception was
//not handled, resulting in an application crash
if IsMasked and (FTextOnEnter Inherited Text) and (not
FValidationFailed) then
begin
//assume failure
try
//debugln('TCustomMaskedit.DoExit: try ValidateEdit');
FValidationFailed := True;
ValidateEdit;
FValidationFailed := False;
finally
if FValidationFailed then
begin
//debugln('TCustomMaskedit.DoExit: Validation failed');
SetFocus;
SelectAll;
end;
end;
end;
{$ENDIF}
end;This functions just fine, as long as the user uses the mouse to leave the control, if the user presses Tab things go wrong:
Here's the sequence of events when using the mouse
1. DoExit, FValidationFailed = False
2. Default ExceptionHandler kicks in with a showmessage
3. DoEnter, FValidationFailed = True
Now with the user pressing Tab
1. DoExit, FValidationFailed = False
2. DoEnter, FValidationFailed = True
3. Default ExceptionHandler kicks in with a showmessage
4. DoEnter, FValidationFailed = False
In the latter case, the second DoEnter will set FTextOnEnter because FValidationFailed now is False and Reset does not work properly.
Has anyone of you an idea how to solve this?
Thanks,
Bart