I am writing column and cell classes for FMX TGrid that will contain TCalendarEdit and TTimeEdit instances in every cell. Everything works fine except the proper processing of changes done in these child controls.
type
TFMTValue<T> = record
FieldValue: T;
Modified: boolean;
Appended: boolean;
Deleted: boolean;
end;
TDateTimeCell = class(TStyledControl)
private
FDate_Time: TFMTValue<TDateTime>;
procedure SetDateTime(const Value: TFMTValue<TDateTime>);
function GetDateTime: TFMTValue<TDateTime>;
protected
procedure SetData(const Value: TValue); override;
public
property Date_Time: TFMTValue<TDateTime> read GetDateTime write SetDateTime;
…
end;
…
function TDateTimeCell.GetDateTime: TFMTValue<TDateTime>;
begin
FDate_Time.Modified := (FDate_Time.Modified) or
(FDate_Time.FieldValue <> FCalendarEdit.Date +
+ FTimeEdit.Time);
FDate_Time.FieldValue := FCalendarEdit.Date + FTimeEdit.Time;
Result := FDate_Time;
end;
procedure TDateTimeCell.SetData(const Value: TValue);
begin
Date_Time := Value.AsType<TFMTValue<TDateTime>>;
inherited SetData(TValue.From<TDateTime>(FDate_Time.FieldValue));
ApplyStyling;
end;
procedure TDateTimeCell.SetDateTime(const Value: TFMTValue<TDateTime>);
begin
FDate_Time := Value;
FCalendarEdit.Date := DateOf(FDate_Time.FieldValue);
FTimeEdit.Time := TimeOF(FDate_Time.FieldValue);
FDate_Time.FieldValue:=FCalendarEdit.Date + FTimeEdit.Time; //this line helps but not in all cases
end;
The idea is that data is assigned via TGrid OnGetValue event handler. Both date and time are displayed. The user activity is catched and Modified flag is set. The problem is that this flag is set to true sometimes even without any user activities. I suspect it is due to the rounding of time part of TDateTime. There are no other ways the code assignes values to FCalendarEdit.Date and FTimeEdit.Time.
How can I properly compare the data stored in FCalendarEdit.Date and FTimeEdit.Time with that stored in FDate_Time.FieldValue?
Appended
Setting the flag in this way does not resolve the issue.
FDate_Time.Modified := (FDate_Time.Modified) or
(DateOf(FDate_Time.FieldValue) <> FCalendarEdit.Date) or
(TimeOf(FDate_Time.FieldValue)<> FTimeEdit.Time);
Appended 2. On a valued advice of @Ken-White.
If we replace the comparison line by
FDate_Time.Modified := (FDate_Time.Modified) or
(not SameDateTime(FDate_Time.FieldValue,
FCalendarEdit.Date + FTimeEdit.Time));
It works fine. So the TDataTime comparison must be done by this function only.
