[solved] looping direction controlled by flag

[Josh]

indeed,
adds more code but function can be tided up,
even the directiion can be set in the create

Code: Pascal  [Select][+][-]

1. TControlIterator = class
2.   private
3.     F_Controls: TArray<TControl>;
4.     F_Index: Integer;
5.     F_Step: Integer;
6.     F_Low, F_High: Integer;
7. ........
8. ........
9. constructor TControlIterator.Create(const Controls: TArray<TControl>; IsFirst: Boolean);
10. begin
11.   F_Controls := Controls;
12.   F_Low := Low(Controls);
13.   F_High := High(Controls);
14.  
15.   if IsFirst then
16.   begin
17.     F_Index := F_Low;  // Start from the beginning
18.     F_Step := 1;      // Move forward
19.   end
20.   else
21.   begin
22.     F_Index := F_High; // Start from the end
23.     F_Step := -1;     // Move backward
24.   end;
25. end;                  
26.  
27. .......
28.  
29.  

and function

Code: Pascal  [Select][+][-]

1. function GetTheControl(const IsFirst: Boolean): TControl;
2. var
3.   Flight: TControlIterator;
4.   Cntrl: TControl;
5. begin
6.   Flight := TControlIterator.Create(AR_CONTROLS, IsFirst);
7.   try
8.     while Flight.HasNext do
9.     begin
10.       Cntrl := Flight.Next;
11.       if Provides_SQL(Cntrl) then  Exit(Cntrl);
12.     end;
13.   finally
14.     Flight.Free;
15.   end;
16.   Error_Halt('No matching control found.');
17. end;
18. end;  

[Joanna from IRC]

Hi
Another possibility would be to utilize 'case', like this:

Code: Pascal  [Select][+][-]

1. var x: integer;
2. begin
3.   case IsFirst of
4.     false: begin
5.              for x:= ControlCount-1 downto 0 do
6.                if Controls[x].Name = 'Memo1' then exit(Controls[x]);
7.            end;
8.     true: begin
9.             for x:= 0 to ControlCount-1 do
10.               if Controls[x].Name = 'Edit1' then exit(Controls[x]);
11.           end
12.   end;
13.   Result:= nil;
14.   fPresenter.Provider.NotifySubscribers(prStatus,nil,Str2Pch('(!) Attention: Control was not found! '));
15. end;
16.  

I hope you get the gist of the algorithm, 'cause I really don't wanna mess with your caps-locked-code...
Regards Benny

Or this

Code: Pascal  [Select][+][-]

1.  FUNCTION TCASCADING_FLOWPANEL.GET_THE_CONTROL(CONST IS_FIRST:BOOLEAN):TCONTROL;
2.          VAR X:INTEGER;
3. BEGIN
4. CASE IS_FIRST OF
5.         TRUE: FOR X:= LOW(AR_CONTROLS) TO HIGH(AR_CONTROLS) DO
6.                          IF PROVIDES_SQL(AR_CONTROLS[X])THEN EXIT(AR_CONTROLS[X]);
7.          FALSE: FOR X:= HIGH(AR_CONTROLS) DOWNTO LOW(AR_CONTROLS) DO
8.                            IF PROVIDES_SQL(AR_CONTROLS[X])THEN EXIT(AR_CONTROLS[X]);
9.           END;
10. ERROR_HALT('FUNCTION TCASCADING_FLOWPANEL.GET_THE_CONTROL');
11. END;  

[cdbc]

Hi Joanna
Yup, I think you've got it =^
I'll just put on my shades  , so I don't get an 'Eye-Sore'... 
Regards Benny

[440bx]

For some reason, Pascal code looks horrible in all uppercase.

[Joanna from IRC]

cdbc i liked the idea of the case because even though my
two if statements could never both be true  its still sort of sloppy to call both of them. The case gives less ambiguity in what will happen if thats the correct term...

[cdbc]

Hi Joanna
Yup, I think 'case' makes for clear code.
Regards Benny