using the clipboard for communicatign between programs
#11
(10-23-2022, 08:41 PM)bplus Wrote:
(10-23-2022, 08:36 PM)Spriggsy Wrote: Microsoft discourages usage of the clipboard in this manner but if it works for your specific purpose then nice.

Did they give a reason to go along with discouragement?
Some people went as far as copying and pasting passwords, credit card data and stuff like that and were hijacked for it, didn't know a malicious program was able to force copy into the clipboard somehow, or block the attempt by the system to clear the clipboard. It must have peaked off enough people going into or out of a web browser then trying to paste text somewhere. Like when I tried one of @Pete's programs to trigger an URL that resided on the clipboard.

In the past a malicious program could put something into the clipboard to disable something in Internet Explorer. Other things could be done that way because a few companies insisted in providing data into or obtaining data from the clipboard, from paying customers. It sounds paranoid, because there's Data Execution Prevention and stuff like that to check certain sensitive areas of RAM periodically. However, it might be a reason why Windows Defender and/or anti-virus slow things down where they don't have to (eg. computer kept totally offline for weeks).
Reply
#12
Thumbs Up 
Interesting, thanks! Powerful tools are also dangerous.
b = b + ...
Reply
#13
No fancy local hosting in this example but it is a useful example on how to use _clipboard$ to open another window (well it's really another program) to serve as a control panel.

A simple ascii doodle program that will let the user doodle in the window with the mouse.
(EDIT: updated to use colorpick16.exe)

Code: (Select All)
'clipboard communcation sample
'an ascii doodle pad that opens a control panel app in another window
'
Screen _NewImage(60, 30, 0)
_Title "ClipDoodle"
Cls
_Clipboard$ = "ClipDoodleOn" ' "clears" clipboard for use
Shell _DontWait "pickclip.exe" ' Open the pickclip control panel
Shell _DontWait "colorpick16.exe" ' Open the color control panel

_ControlChr Off
AK = 42
Do
    _Limit 100
    Do While _MouseInput 'mouse status changes only
        _Limit 2000
        x = _MouseX
        y = _MouseY

        If _MouseButton(1) Then
            _PrintString (x, y), brush$
        End If
    Loop
    kk$ = InKey$
    ik$ = _Clipboard$
    If Left$(ik$, 2) = "AC" Then AK = Val(Right$(ik$, Len(ik$) - 2))
    If Left$(ik$, 2) = "CK" Then
        ff$ = " "
        n = 2
        Do
            n = n + 1
            A$ = Mid$(ik$, n, 1)
            If A$ <> "/" Then ff$ = ff$ + A$
        Loop Until A$ = "/"
        bb$ = ""
        Do
            A$ = Mid$(ik$, n, 1)
            If A$ <> "/" Then bb$ = bb$ + A$
            n = n + 1
        Loop Until n > Len(ik$)
        FG = Val(ff$): BG = Val(bb$)
        Color FG, BG
    End If
    brush$ = Chr$(AK)
Loop Until kk$ = Chr$(27)
_Clipboard$ = "QUITCOLORPICK16"
Sleep 1
_Clipboard$ = "QUITCLIPPICK"
System


compile this part as pickclip.exe
Code: (Select All)
'pickclip
'complie as pickclip.exe
'sample of a "control panel" feeding output to the clipboard
Screen _NewImage(33, 20, 0)
_ScreenMove 600, 0
_Title "Pick Clip"
_ControlChr Off
AA = 0
'builds ascii grid
For y = 1 To 16
    For x = 1 To 16
        _PrintString (x * 2, y), Chr$(AA)
        AA = AA + 1
    Next
Next
Do
    _Limit 100
    Do While _MouseInput 'mouse status changes only
        x = _MouseX
        y = _MouseY
        If _MouseButton(1) Then
            x = Int(x / 2)
            AK = (y - 1) * 16 + (x - 1)
            _PrintString (1, 18), "                     "
            If AK > -1 And AK < 256 Then pp$ = "Picked ASCII " + Str$(AK) + " : " + Chr$(AK)
            _PrintString (1, 18), pp$
            _Clipboard$ = "AC" + Str$(AK)
        End If
    Loop
    kk$ = InKey$
    If _Clipboard$ = "QUITCLIPPICK" Then kk$ = "QUITALL"
Loop Until kk$ = "QUITALL" Or kk$ = "Q"
_Clipboard$ = "pickclip did quit" 'so QUIT message isn't left in clipboard
System


When both are compiled clipdoodle will open pickclip. Anytime you click on a character to select it that character will get put in the clipboard as "AC"+ascii# to be read by clipdoodle. If you accidentally close pickclip you can reopen it again without impacting the clipdoodle.
When you quit clipdoodle by pressing <esc> it will put a message on the clipboard telling pickclip to quit as well.
Reply
#14
added a color picker to the clipdoodle program above.

compile as colorpick16.exe
Code: (Select All)
'colorpick16
'
'a color picker for mode 0 screens.
'
Screen _NewImage(32, 8, 0)
_ScreenMove 600, 400
_Title "colorpick16"
For y = 0 To 1
    For x = 0 To 7
        fk = y * 8 + x
        p$ = "[  ]"
        a$ = _Trim$(Str$(fk))
        If Len(a$) = 1 Then
            Mid$(p$, 3, 1) = a$
        Else
            Mid$(p$, 2, 2) = a$
        End If
        Color fk, 0
        If fk = 0 Then Color 0, 7
        _PrintString ((x + 1) * 4 - 3, y + 1), p$
    Next
Next
_PrintString (1, 4), "Foreground"
_PrintString (1, 5), "Background"
For x = 0 To 7
    bk = x
    p$ = "[  ]"
    a$ = _Trim$(Str$(bk))
    Mid$(p$, 3, 1) = a$
    Color 0, bk
    If bk = 0 Then Color 15, 0
    _PrintString ((x + 1) * 4 - 3, 7), p$
Next
fk = 15: bk = 0
Do
    _Limit 100
    Do While _MouseInput 'mouse status changes only
        x = _MouseX
        y = _MouseY
        If _MouseButton(1) Then
            If y >= 1 And y <= 2 Then
                fk = (y - 1) * 8 + Int(x / 4)
            End If
            Color fk, 0
            If fk = 0 Then Color fk, 8
            _PrintString (12, 4), "    "
            _PrintString (12, 4), Str$(fk)
            If y = 7 Then
                bk = Int(x / 4)
            End If
            Color fk, bk
            _PrintString (12, 5), "    "
            _PrintString (12, 5), Str$(bk)
            _Clipboard$ = "CK" + _Trim$(Str$(fk)) + "/" + _Trim$(Str$(bk))
        End If
    Loop
    kk$ = InKey$
    ccheck$ = _Clipboard$
    If ccheck$ = "QUITCOLORPICK16" Then kk$ = "QUITCOLORPICK16"
Loop Until kk$ = Chr$(27) Or kk$ = "QUITCOLORPICK16"
_Clipboard$ = "pickcolor quit"

System


This will enable the user to change foreground and background colors in the clipdoodle sample posted earlier.
Reply




Users browsing this thread: 5 Guest(s)