File Navigator 1.0: a simple demo for an ASCII scroll-list of files in folder

[TempodiBasic]

Hi
in pure QBasic
here a simple demonstration about how to do a scroll-list with selection of some elements.
The input of list is from a file, but it can be changed at your need.
The input of user is keyboard, but it can be expanded at your need to mouse and joystick.
The output is an ASCII boxed scrollable list, but it can be changed in graphic primitive or graphic images at your need.
 
in this case I use this method to show the files of a folder.

Code: QB64: [Select]

1. DECLARE SUB AllList (Max AS INTEGER)
2. Const Max = 500
3. Dim F(1 To Max) As String, S(1 To Max) As String * 2
4. Dim wide As Integer, n As Integer, a As Integer, i As Integer, Upper As Integer
5. n = 0
6. NameFile$ = "filedir.tmp"
7. On Error GoTo Nofile
8. Color 7, 0
9. Cls
10. Shell "dir  /b> " + NameFile$
11. Open NameFile$ For Input As #1
12. While Not EOF(1)
13.     n = n + 1
14.     Line Input #1, F(n)
15.     S(n) = "  "
16.     If wide < Len(F(n)) Then wide = Len(F(n))
17. Wend
18. Close #1
19.  
20. On Error GoTo 0
21. Kill NameFile$
22. Upper = n
23.  
24. 'AllList Upper
25. Cls
26. ChoiceList Upper, wide
27.  
28. End
29.  
30. Nofile:
31. Print " Error "; FileName$ + " not found!"
32. End
33. Resume Next
34.  
35.  
36. Sub ChoiceList (Umax As Integer, wid As Integer)
37.     Shared F() As String, S() As String * 2
38.     a = 0
39.     k$ = ""
40.     If i = 0 Then i = 1: n = i
41.     ' 183 · 186º 189 ½ 196 Ä 211 Ó 214  Ö
42.  
43.     Do
44.         ' here is the output of list
45.         Color 7, 0
46.         If i < n Or i > (n + 15) Then n = i
47.         Locate 4, 23
48.         Print "Ö" + String$(wid + 3, "Ä") + "·"
49.         For a = n To n + 15 Step 1
50.             If a > Umax Then M$ = Space$(wid + 3) Else M$ = " " + F(a) + S(a) + Space$(wid - Len(F(a)))
51.             If a = i Then Color 15, 0
52.             Locate , 23
53.             Print "º" + M$ + "º"
54.             If a = i Then Color 7, 0
55.         Next a
56.         Locate , 23
57.         Print "Ó" + String$(wid + 3, "Ä") + "½"
58.         Locate , 23
59.         Print Chr$(24) + Chr$(25) + " move, S select, D done"
60.  
61.  
62.  
63.         ' here is the user input from keyboard
64.         Do
65.             k$ = UCase$(InKey$)
66.             ' it switches the selector
67.             If k$ = "S" Then If S(i) = "  " Then S(i) = "<-" Else S(i) = "  "
68.             ' down
69.             If k$ = Chr$(0) + "P" Then If i < Umax Then i = i + 1
70.             'up
71.             If k$ = Chr$(0) + "H" Then If i > 1 Then i = i - 1
72.             If k$ = "D" Then Exit Sub 'Return ' all selection has been done
73.         Loop Until k$ <> ""
74.     Loop
75.     'Return
76. End Sub
77.  
78. Sub AllList (UMax As Integer)
79.     Shared F() As String, S() As String * 2
80.     ' debug SUB to show the whole list
81.     For a = 1 To UMax Step 1
82.         Print F(a) + S(a)
83.         If a Mod 15 = 0 Then Sleep 2
84.     Next a
85. End Sub
86.  

Happy Coding in the New Year!

PS: QB64 beats QBasic for NOT get back a QBasic Parser bug:
If you DIM a string array suffix, if you SHARED that string array from into the SUB, you cannot use the suffix for define datatype but you must use AS.
Doing so you fall in Parser error that alert you; SUB shared variable isn't declared at main module! LOL

Instead QB64 recognizes that the same name with or without suffix  are the same if declared as the same type of data.
Here the issue of Qbasic showed in code.

Code: QB64: [Select]

1. DIM Me$ (1 to 10)
2.  
3. 'main
4.  
5. END
6. SUB foo
7. SHARED Me () AS STRING
8. END SUB