Mutex and Firefly

[Richard Marchessault]

What code would you recommend to determine if a program is already and switch to the running program instead of starting it up again? I can see examples of using CreateMutex on the PowerBasic forums but wonder how best to implement this with FireFly.

[Pierre Bellisle]

Sadly, I'm not a FireFly user, but still, here is the same Mutex & GW_HWNDNEXT approach I had in PowerBASIC...

Code Select Expand


#Define JumpCompiler "<D:\Free\64\fbc.exe>" 'Compiler to use "< = left delimiter, >" = right delimiter
#Define JumpCompilerCmd "<-s gui -w pedantic "D:\Free\bas\~~Default.rc">" 'Command line to send to compiler (gui or console)

#define UniCode
#Include Once "windows.bi"
#Include Once "win\shellapi.bi"

#Define AppName "Mutex demo"
#Define StaticInfo 101
#Define CrLf Chr(13, 10)
#Define dwMutex 1901310955 '[YYMMDDHHMM] - 10 digits - Max is 4,294,967,295, I use current time

Dim Shared As HINSTANCE hInstance : hInstance = GetModuleHandle(NULL)
'_____________________________________________________________________________

Function WndProc(ByVal hWnd As HWND, ByVal uMsg As UINT, ByVal wParam As WPARAM, ByVal lParam As LPARAM) As Integer
Dim    hStaticInfo        As HWND
Static hWindowDefaultFont As HFONT

Function = 0

Select Case (uMsg)

   Case WM_CREATE
     Dim As NONCLIENTMETRICS NotClientMetrics
     NotClientMetrics.cbSize = SizeOf(NONCLIENTMETRICS)
     SystemParametersInfo(SPI_GETNONCLIENTMETRICS, NotClientMetrics.cbSize, @NotClientMetrics, 0)
     hWindowDefaultFont = CreateFontIndirect(@NotClientMetrics.lfMessageFont)

     hStaticInfo = CreateWindowEx(0, "Static", "Try to run another self instance" & CRLF & "(Minimize me before)", _
                                  WS_CHILD Or WS_VISIBLE Or SS_CENTER Or SS_NOTIFY, _
                                  10, 30, 200, 30, _
                                  hWnd, Cast(HMENU, StaticInfo), _
                                  hInstance, NULL)
    SendMessage(hStaticInfo, WM_SETFONT, Cast(UInteger, hWindowDefaultFont), TRUE)

   Case WM_DESTROY
     DeleteObject(hWindowDefaultFont) 'Clean up
     PostQuitMessage(0) 'Ask message loop to end
     Exit Function

End Select

Function = DefWindowProc(hWnd, uMsg, wParam, lParam)

End Function
'_____________________________________________________________________________

Function WinMain(ByVal hInstance As HINSTANCE, ByVal hPrevInst As HINSTANCE, _
                 ByVal CmdLine As WString Ptr, ByVal CmdShow As Integer) As UINT
Dim WinClass   As WNDCLASS
Dim wMsg       As MSG
Dim hWnd       As HWND
Dim hIco       As HICON
Dim WindowSize As SIZEL
Dim wsAppName  As WString * 128

wsAppName              = AppName
WindowSize.cx          = 230
WindowSize.cy          = 120
hIco                   = ExtractIcon(GETMODULEHANDLE(""), "Shell32.dll", 294) 'o
WinClass.style         = CS_HREDRAW Or CS_VREDRAW
WinClass.lpfnWndProc   = ProcPtr(WndProc)
WinClass.cbClsExtra    = 0
WinClass.cbWndExtra    = 0
WinClass.hInstance     = hInstance
WinClass.hIcon         = hIco
WinClass.hCursor       = LoadCursor(NULL, IDC_ARROW)
WinClass.hbrBackground = Cast(HGDIOBJ, COLOR_BTNFACE + 1) 'Default color
WinClass.lpszMenuName  = NULL
WinClass.lpszClassName = @wsAppName

Dim hTry        As HWND
Dim hMutex      As HWND
Dim zMutex      As ZString * 16

zMutex  = "MyUniqueMutex" 'MaxStringLen is %MAX_PATH, no "\", case sensitive
hMutex  = CreateMutex(ByVal NULL, 0, zMutex)
If GetLastError = ERROR_ALREADY_EXISTS Then
   Beep()
   'Optionnal: MessageBox(HWND_DESKTOP, AppName & " is already running!", AppName, MB_TOPMOST Or MB_OK)
   hTry =  GetForegroundWindow()
   Do While hTry
     If  GetWindowLongPtr(hTry, GWLP_USERDATA) = dwMutex Then
       If IsIconic(hTry) Then ShowWindow(hTry, SW_RESTORE) 'Unminimize exe
       SetForegroundWindow(hTry)
       Exit Do
     End If
     hTry = GetWindow(hTry, GW_HWNDNEXT)
   Loop
   If hTry = 0 Then 'Can't find it!!!
     MessageBox(HWND_DESKTOP, AppName & " is running hidden in background!", AppName, MB_TOPMOST Or MB_OK)
   End IF
   End
End If

If (RegisterClass(@WinClass)) Then
   hWnd = CreateWindowEx(WS_EX_WINDOWEDGE, _
                         wsAppName, wsAppName, _
                         WS_OVERLAPPED OR WS_CLIPCHILDREN Or WS_DLGFRAME Or WS_BORDER Or WS_VISIBLE Or WS_CAPTION Or _
                         WS_MAXIMIZEBOX Or WS_MINIMIZEBOX Or WS_SYSMENU , _
                         (GetSystemMetrics(SM_CXSCREEN) - WindowSize.cx) / 2, _ 'PosX
                         (GetSystemMetrics(SM_CYSCREEN) - WindowSize.cy) / 2, _ 'PosY
                         WindowSize.cx, WindowSize.cy, _ 'Width, height
                         NULL, NULL, hInstance, NULL)

   SetWindowLongPtr(hWnd, GWLP_USERDATA, dwMutex) 'Set window mutex

   ShowWindow(hWnd, SW_SHOW)
   UpdateWindow(hWnd)

   While GetMessage(@wMsg, ByVal NULL, 0, 0) > 0
     If IsDialogMessage(hWnd, @wMsg) = 0 Then
       TranslateMessage(@wMsg)
       DispatchMessage(@wMsg)
     End If
   Wend
End If

DestroyIcon(hIco)

CloseHandle(hMutex)

Function = wMsg.message

End Function
'_____________________________________________________________________________

End WinMain(hInstance, NULL, Command(), SW_NORMAL) 'Call main() and return the error code to the OS
'_____________________________________________________________________________
'


[José Roca]

Pierre,

Firefly uses PowerBasic, not Freebasic.

[Pierre Bellisle]

This was my impression, so I double checked with a quick search and got FireFly for FreeBASIC v3.78 uploaded... by Paul and then because the PowerBASIC's answers where quite explicit I thought Richard was adapting code, I guess that it was kind of a redundant variant of the same question.
In any case, for easy find, the PB equivalent of the above code is at Mutex and GWL_USERDATA

[José Roca]

Sorry, I forgot that there was a version of Firefly for FreeBasic. I wonder why somebody will want to use it, since it was deprecated long time ago.

[Klaas Holland]

I do use FireFly for FreeBasic and I am pleased with it.
That was my way to learn FreeBasic.
Now I am waiting for WinFBE to become as good and easy as FireFly.

[Marc Pons]

@José, I also use Firefly for freebasic and with the extension i have done arround , it is totally usable,
i use it still with freebasic from 0.24  to 1.06 on 32bits and 1.05 or 1.06 on 64bits

in my understanding it is a vey interresting tool to create simple windowed app , I even can make windowed dll with it.
Even COM app using my old axsuite3 adaptation...
until the new Paul's visual editor is not totally done it is a very simple solution for people not wanting to write all sdk stuff.

As a nostalgic of vb6, it was the closest i've found, and hope to find the same simplicity with the new Paul's visual editor (sorry still not tested)

I take here alse the opportunity to thank you again Paul and you José for the great features of your contributions
kind regards
Marc

Paul:  i did not make the evolution on the French translation for your last ide version, (was travelling in your countrie in Montréal)
is it some changes in the existing I have to check or just adding new translations?

[David Kenny]

Dick,

This code is the entire FF_WinMain in one of my old programs. You can get to FF_WinMain from the Firefly Workspace dialog (F9 to activate the dialog). On the Explorer tab, under Special Functions.

Code Select Expand

Function FF_WINMAIN(ByVal hInstance     As Dword, _
                    ByVal hPrevInstance As Dword, _
                    ByVal lpCmdLine     As Asciiz Ptr, _
                    ByVal iCmdShow      As Long) As Long
Local hWin      As   Dword
Local ProgName   As   String
'If this function returns TRUE (non-zero) then the actual WinMain will exit
'thus ending the program. You can do program initialization in this function.
Dim DrSelFlag(5)         
ProgName="User Copy"
If FF_PrevInstance Then
   hWin = FindWindow(ByVal %Null, ByVal StrPtr(ProgName))
   OpenIcon hWin                       '-- Activate the first instance
   SetForegroundWindow hWin
   
   Function = %True    'return %TRUE if you want the program to end.
Else
   Function = %False     
End If

End Function


Just change the ProgramName from "User Copy" to your program name.  The mutex is handled by the FF routine FF_PrevInstance (in the Functions Library - Hit F8 - in the General branch). The rest I got from the PB forums.
It does exactly what you are asking for.

David

[Klaas Holland]

This is the FreeBasic version

Code Select Expand

 
Function FF_WINMAIN ( ByVal hInstance     as HINSTANCE, _
                      ByVal hPrevInstance as HINSTANCE, _
                      ByRef lpCmdLine     as String,    _ 
                      ByVal iCmdShow      as Long       ) as Long

    If FF_PrevInstance Then
        Dim hWin   as Long  =  FindWindow(gFLY_AppID, ByVal 0)
        OpenIcon hWin                                         '-- Activate the first instance
        SetForegroundWindow hWin

        Function = True   
    Else
        Function = False    'return TRUE if you want the program to end.
    End If

End Function


[Wilko Verweij]

Hi, I doubt if this actually works. See : https://docs.microsoft.com/en-us/windows/desktop/api/winbase/nf-winbase-winmain

Type: HINSTANCE

A handle to the previous instance of the application. This parameter is always NULL. If you need to detect whether another instance already exists, create a uniquely named mutex using the CreateMutex function.

So I think this code does not work for modern Windows versions. It should have worked under older versions. See https://stackoverflow.com/questions/7458436/why-does-previnstance-exist-in-winmain-and-wwinmain-if-it-is-always-null

Sorry for spoiling...

The FindWindow / OpenIcon / SetForeGroundWindow is still a useful suggestion (did not test).
Wilko

[José Roca]

I suggest that you reread the post. It is not checking the hPrevInstance parameter, but calling the FF_PrevInstance function, that in turn calls FindWindow.

[Wilko Verweij]

You are right, of course. I overlooked the difference between hPrevInstance and FF_PrevInstance. Sorry for the confusion.