How to enter dates into a TDateTimePicker by keyboard only (Views: 706)
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Problem/Question/Abstract: We have decided to replace all occurrences of TMaskEdit in our applications with TDateTimePicker's (of course only where they were used for entering dates). The problem is making the transition as easy as possible for the users. TDateTimePicker as it is is not very well-suited for keyboard-only input. The first annoyance is that you have to explicitly enter the separators. TMaskEdit just jumped to the next figure if you entered a number instead of the separator character. It becomes worse still when ShowCheckbox is True. In that case the focus is automatically shifted to the checkbox after having entered the first two digits, essentially making it impossible to enter a date by keyboard only (unless you manually cursor to the every single figure). Does anyone know if it possible at all to overcome these limitations by simply subclassing TDateTimePicker? Answer: Here is the routine that I use for date entry edits. Feel free to use it if you just want keyboard entry of dates. Here's the way it works: As the user types in the edit, it's checked against the current ShortDateFormat setting to determine whether it's in the month, day or year portion. If, for instance, they are in the month portion and they type a '3', it knows that it must be the third month and so puts '03' and goes to the next section (if any). If you want to default any portion to the current day, month or year, simply hit the space bar. This gives users a really fast way to fill in dates, especially the current day's. All you need to do is assign the OnKeyPress event of any edit control and make a simple call: DateKeyPress(self, Key); {Included because I use it to tab to the next control when the date is complete} procedure PressTabKey(Shift: boolean = false); begin if Shift then keybd_event(VK_SHIFT, 0, 0, 0); keybd_event(VK_TAB, 0, 0, 0); keybd_event(VK_TAB, 0, KEYEVENTF_KEYUP, 0); if Shift then keybd_event(VK_SHIFT, 0, KEYEVENTF_KEYUP, 0); end; procedure DateKeyPress(Sender: TObject; var Key: char); const Zero: char = '0'; DateParts: array[1..3] of string = ('', '', ''); SeparatorChar: string = ''; procedure GetDateParts; var x, y: integer; s: string; c: char; begin s := ShortDateFormat; y := 1; c := s[1]; for x := 1 to length(s) do if (s[x] <> DateSeparator) then begin if (s[x] <> c) then begin c := s[x]; inc(y); end; DateParts[y] := DateParts[y] + s[x]; end else begin inc(y); c := s[x + 1]; end; if pos(DateSeparator, s) <> 0 then SeparatorChar := DateSeparator else SeparatorChar := ''; end; function FixDatePart(s: string; Part: integer): string; begin if (s <> '') and (s[length(s)] = DateSeparator) then delete(s, length(s), 1); if (s = '') then s := FormatDateTime(DateParts[Part], Now); if (DateParts[Part][1] in ['m', 'M', 'd', 'D']) then result := format('%.' + IntToStr(length(DateParts[Part])) + 'd', [StrToInt(s)]) else if (length(s) < length(DateParts[Part])) then result := copy(FormatDateTime(DateParts[Part], Now), 1, length(Dateparts[Part]) - length(s)) + s else result := s; end; var s: string; x, sepLength: integer; begin if DateParts[1] = '' then GetDateParts; if ord(Key) in ActionKeys then exit; s := copy(TEdit(Sender).Text, 1, TEdit(Sender).SelStart); x := length(s); sepLength := length(SeparatorChar); case Key of ' ': begin if (x = length(DateParts[1]) + sepLength) then s := s + FixDatePart('', 2) + SeparatorChar else if (x = length(DateParts[1] + DateParts[2]) + (sepLength * 2)) then s := s + FixDatePart('', 3) else if (x = 0) then s := FixDatePart('', 1) + SeparatorChar else if (x <= length(DateParts[1])) then s := FixDatePart(s, 1) + SeparatorChar + FixDatePart('', 2) + SeparatorChar else if (x <= (length(DateParts[1] + DateParts[2]) + (sepLength * 2))) then s := copy(s, 1, length(DateParts[1]) + sepLength) + FixDatePart(copy(s, length(DateParts[1]) + sepLength + 1, length(s)), 2) + SeparatorChar + FormatDateTime(DateParts[3], Now) else s := copy(s, 1, length(DateParts[1] + DateParts[2]) + (sepLength * 2)) + FixDatePart(copy(s, length(DateParts[1] + DateParts[2]) + (sepLength * 2) + 1, length(s)), 3); TEdit(Sender).Text := s; Key := #0; TEdit(Sender).SelStart := length(s); end; '0'..'9': begin if (x in [length(DateParts[1]), length(DateParts[1] + DateParts[2]) + sepLength]) then s := s + SeparatorChar + Key else if (x = 0) and (((DateParts[1][1] in ['m', 'M']) and (Key in ['2'..'9'])) or((DateParts[1][1] in ['d', 'D']) and (Key in ['4'..'9']))) then s := FixDatePart(Key, 1) + SeparatorChar else if (x = length(DateParts[1]) + sepLength) and (((DateParts[2][1] in ['m', 'M']) and (Key in ['2'..'9'])) or ((DateParts[2][1] in ['d', 'D']) and (Key in ['4'..'9']))) then s := s + FixDatePart(Key, 2) + SeparatorChar else s := s + Key; if (length(s) = length(DateParts[1])) or (length(s) = length(DateParts[1] + DateParts[2]) + sepLength) then s := s + SeparatorChar; TEdit(Sender).Text := s; Key := #0; TEdit(Sender).SelStart := length(s); end; { uncomment this to use N/A values 'n','N': begin TEdit(Sender).Text := 'N/A'; TEdit(Sender).SelStart := 0; TEdit(Sender).SelLength := 3; Key := #0; end;} else begin if (Key = DateSeparator) then begin if s[x] <> DateSeparator then begin if x = length(DateParts[1]) - 1 then s := Zero + s + DateSeparator else if x = 4 then begin insert(Zero, s, 4); s := s + '/'; end; end; TEdit(Sender).Text := s; Key := #0; TEdit(Sender).SelStart := length(s); end else Key := #0; end; end; if length(TEdit(Sender).Text) = length(ShortDateFormat) then PressTabKey; end; |