[Solved] Console program with select menu

[nikel]

Hello, I'm trying to make a selection menu for my console program. I couldn't make hover background but I made it using an arrow to mark. I moved the code to a new class but it's not working now. Here's my code.

Code: Pascal  [Select][+][-]

1. constructor TMenu.Create();
2. begin
3.   FSelectedIndex:=-1;
4.   FStartIndex:=-1;
5.   FMark:='     ';
6.   FListOfLines:=TStringList.Create;
7.   FListOfLines.Sorted:=False;
8. end;
9.  
10. destructor TMenu.Destroy;
11. begin
12.   FListOfLines:=nil;
13.   FListOfLines.Free;
14. end;
15.  
16. procedure TMenu.AddText(T: string);
17. begin
18.   FListOfLines.Add(T);
19. end;
20.  
21. procedure TMenu.AddChoiceItem(Ci: string; S: Boolean);
22. begin
23.   FListOfLines.Add(Ci);
24.  
25.   // Set start index
26.   if (FStartIndex = -1) then
27.   begin
28.     FStartIndex:=FListOfLines.Count - 1;
29.   end;
30.  
31.   // Set end index
32.   FEndIndex:=FListOfLines.Count - 1;
33.  
34.   // Add it according to state of selection
35.   if (S = True) then
36.   begin
37.     FSelectedIndex:=FStartIndex;
38.     FMark:=' --->';
39.   end
40.   else
41.   begin
42.     FMark:='     ';
43.   end;
44.  
45.   FListOfLines[FListOfLines.Count - 1]:=FMark + FListOfLines[FListOfLines.Count - 1];
46. end;
47.  
48. procedure TMenu.AddSeparator;
49. begin
50.   FListOfLines.Add(#10);
51. end;
52.  
53. procedure TMenu.OnChoice(K: Char);
54. var
55.   I       : Integer;
56. begin
57.   if (K = #72) and (FSelectedIndex > FStartIndex) then
58.   begin
59.     FListOfLines[FSelectedIndex]:=ReplaceStr(FListOfLines[FSelectedIndex], '     ', ' --->');
60.     FSelectedIndex:=FSelectedIndex - 1;
61.   end
62.   else if (K = #80) and (FSelectedIndex < FEndIndex) then
63.   begin
64.     FListOfLines[FSelectedIndex]:=ReplaceStr(FListOfLines[FSelectedIndex], '     ', ' --->');
65.     FSelectedIndex:=FSelectedIndex + 1;
66.   end;
67. end;

Here's how I call the class.

Code: Pascal  [Select][+][-]

1. Menu:=TMenu.Create();
2. Menu.AddText('Is this bpm correct: ' + B.ToString);
3. Menu.AddText('for the file ' + Nm);
4. Menu.AddSeparator;
5. Menu.AddChoiceItem('Yes', True);
6. Menu.AddChoiceItem('Make it half', False);
7. Menu.AddChoiceItem('Custom', False);
8. Menu.AddSeparator;
9. Menu.AddText('(Press escape to exit)');
10.  
11. repeat
12.   ClrScr;
13.   Writeln;Writeln;Writeln;
14.  
15.   for I:=0 to Menu.ListOfLines.Count - 1 do
16.   begin
17.     WriteLn(Menu.ListOfLines[I]);
18.   end;
19.  
20.   Key:=ReadKey;
21.    if Key=#0 then
22.       Key:=ReadKey;
23.  
24.   if (Key = #72) then
25.   begin
26.     Menu.OnChoice(#72);
27.   end
28.   else if (Key = #80) then
29.   begin
30.     Menu.OnChoice(#80);
31.   end;
32. until Key = #27;
33.  
34. Menu.Destroy;
35. Menu:=nil;
36. Menu.Free;

When I hit down arrow nothing happens. How can I make it work?

[Thaddy]

Have a look at the FreeVision demo.

[nikel]

Thank you for your reply. FreeVision is too complex for me.

[nikel]

It was a careless mistake. I had to change OnChoice function and set the variable first.

[dseligo]

It was a careless mistake. I had to change OnChoice function and set the variable first.

You also have error in OnDestroy. You first set FListOfLines to nil, and after that you call Free. It should be other way around.

P.S.: And in the main program similar:

Code: Pascal  [Select][+][-]

1. Menu.Destroy;
2. Menu:=nil;
3. Menu.Free;

Do it like this:

Code: Pascal  [Select][+][-]

1. Menu.Free;
2. Menu:=nil; // this is optional, you don't have to do it