Initial commit

singleinstance.sln

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+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 2013
+VisualStudioVersion = 12.0.40418.0
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "singleinstance", "singleinstance\singleinstance.vcxproj", "{95C5CED1-7955-43FC-9EA3-E20D2CE1DEB1}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Win32 = Debug|Win32
+		Release|Win32 = Release|Win32
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{95C5CED1-7955-43FC-9EA3-E20D2CE1DEB1}.Debug|Win32.ActiveCfg = Debug|Win32
+		{95C5CED1-7955-43FC-9EA3-E20D2CE1DEB1}.Debug|Win32.Build.0 = Debug|Win32
+		{95C5CED1-7955-43FC-9EA3-E20D2CE1DEB1}.Release|Win32.ActiveCfg = Release|Win32
+		{95C5CED1-7955-43FC-9EA3-E20D2CE1DEB1}.Release|Win32.Build.0 = Release|Win32
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+EndGlobal

singleinstance/Resource.h

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+//{{NO_DEPENDENCIES}}
+// Microsoft Visual C++ generated include file.
+// Used by singleinstance.rc
+//
+
+#define IDS_APP_TITLE			103
+
+#define IDR_MAINFRAME			128
+#define IDD_SINGLEINSTANCE_DIALOG	102
+#define IDD_ABOUTBOX			103
+#define IDM_ABOUT				104
+#define IDM_EXIT				105
+#define IDI_SINGLEINSTANCE			107
+#define IDI_SMALL				108
+#define IDC_SINGLEINSTANCE			109
+#define IDC_MYICON				2
+#ifndef IDC_STATIC
+#define IDC_STATIC				-1
+#endif
+// Next default values for new objects
+//
+#ifdef APSTUDIO_INVOKED
+#ifndef APSTUDIO_READONLY_SYMBOLS
+
+#define _APS_NO_MFC					130
+#define _APS_NEXT_RESOURCE_VALUE	129
+#define _APS_NEXT_COMMAND_VALUE		32771
+#define _APS_NEXT_CONTROL_VALUE		1000
+#define _APS_NEXT_SYMED_VALUE		110
+#endif
+#endif

singleinstance/singleinstance.cpp

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+// singleinstance.cpp : Defines the entry point for the application.
+//
+
+#include "stdafx.h"
+
+/**
+This app allows to select multiple files and launch one instance of command process from windows explorer's context menu.
+
+Example of usage:
+
+Windows Registry Editor Version 5.00
+
+[HKEY_CLASSES_ROOT\SystemFileAssociations\.txt\Shell\p4merge]
+"MultiSelectModel"="Player"
+
+[HKEY_CLASSES_ROOT\SystemFileAssociations\.txt\Shell\p4merge\Command]
+@="\"d:\\singleinstance.exe\" %1 \"C:\\Program Files\\Perforce\\p4merge.exe\" $files --si-timeout 400"
+
+*/
+#include <Shellapi.h>
+#include <vector>
+#include <string>
+
+class CLimitSingleInstance {
+protected:
+    DWORD  m_dwLastError;
+    HANDLE m_hMutex;
+
+public:
+    CLimitSingleInstance(TCHAR *strMutexName)
+    {
+        m_hMutex = CreateMutex(NULL, FALSE, strMutexName); //do early
+        m_dwLastError = GetLastError(); //save for use later...
+    }
+
+    ~CLimitSingleInstance(){
+        if (m_hMutex)  //Do not forget to close handles.
+        {
+            CloseHandle(m_hMutex); //Do as late as possible.
+            m_hMutex = NULL; //Good habit to be in.
+        }
+    }
+
+    BOOL IsAnotherInstanceRunning(){
+        return (ERROR_ALREADY_EXISTS == m_dwLastError);
+    }
+};
+
+int timeout = 400; // ms
+enum { TIMER_ID = 1 };
+LPTSTR *szArgList;
+int argCount;
+CLimitSingleInstance singleInstance(TEXT("Global\\{C30D92DD-DEE6-41A1-8907-B42FBE58C8A6}"));
+std::vector<std::wstring> files;
+HINSTANCE hInst;                                // current instance
+TCHAR szWindowClass[256] = _T("SingleInstance_WindowClass");            // the main window class name
+
+// Forward declarations of functions included in this code module:
+ATOM                MyRegisterClass(HINSTANCE hInstance);
+BOOL                InitInstance(HINSTANCE, int);
+LRESULT CALLBACK    WndProc(HWND, UINT, WPARAM, LPARAM);
+
+int APIENTRY _tWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPTSTR lpCmdLine, int nCmdShow) {
+    szArgList = CommandLineToArgvW(GetCommandLine(), &argCount);
+    for (int i = 0; i < argCount; i++) {
+        if (!lstrcmp(szArgList[i], _T("--si-timeout")) && i + 1 < argCount ) {
+            timeout = std::stoi(szArgList[i + 1]);
+        }
+    }
+
+    if (singleInstance.IsAnotherInstanceRunning()) {
+        for (;;) {
+            DWORD startTime = GetTickCount();
+            HWND wnd = FindWindow(szWindowClass, NULL);
+            if (wnd) {
+                LPCTSTR lpszString = szArgList[1];
+                COPYDATASTRUCT cds;
+                cds.dwData = 1; // can be anything
+                cds.cbData = sizeof(TCHAR) * (_tcslen(lpszString) + 1);
+                cds.lpData = (void*)lpszString;
+                SendMessage(wnd, WM_COPYDATA, (WPARAM)wnd, (LPARAM)(LPVOID)&cds);
+                break;
+            } else {
+                Sleep(50);
+                if (GetTickCount() - startTime > timeout ) {
+                    break; // failure
+                }
+            }
+        }
+        LocalFree(szArgList);
+        return 0;
+    }
+
+    if (szArgList  ) {
+        if (argCount > 3) {
+            files.push_back(szArgList[1]);
+        } else {
+            MessageBox(0, L"Usage: singleinstance.exe \"%1\" <command> $files [arguments]\r\n\r\n"
+                L"Optional arguments for singleinstance (not passed to command):\r\n"
+                L"--si-timeout <time to wait in msecs>"
+                , _T("singleinstance"), 0);
+            return 0;
+        }
+    }
+
+    MSG msg;
+
+    // Initialize global strings
+    MyRegisterClass(hInstance);
+
+    // Perform application initialization:
+    if (!InitInstance (hInstance, nCmdShow)) {
+        return FALSE;
+    }
+
+    // Main message loop:
+    while (GetMessage(&msg, NULL, 0, 0)) {
+        TranslateMessage(&msg);
+        DispatchMessage(&msg);
+    }
+    LocalFree(szArgList);
+    return (int) msg.wParam;
+}
+
+ATOM MyRegisterClass(HINSTANCE hInstance)
+{
+    WNDCLASSEX wcex;
+
+    wcex.cbSize = sizeof(WNDCLASSEX);
+
+    wcex.style            = CS_HREDRAW | CS_VREDRAW;
+    wcex.lpfnWndProc    = WndProc;
+    wcex.cbClsExtra        = 0;
+    wcex.cbWndExtra        = 0;
+    wcex.hInstance        = hInstance;
+    wcex.hIcon = 0;
+    wcex.hCursor        = LoadCursor(NULL, IDC_ARROW);
+    wcex.hbrBackground    = (HBRUSH)(COLOR_WINDOW+1);
+    wcex.lpszMenuName = 0;
+    wcex.lpszClassName    = szWindowClass;
+    wcex.hIconSm = 0;
+
+    return RegisterClassEx(&wcex);
+}
+
+BOOL InitInstance(HINSTANCE hInstance, int nCmdShow) {
+   HWND hWnd;
+
+   hInst = hInstance; // Store instance handle in our global variable
+   hWnd = CreateWindow(szWindowClass, _T("SingleInstance"), WS_OVERLAPPEDWINDOW,
+      CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, NULL, NULL, hInstance, NULL);
+
+   if (!hWnd)
+   {
+      return FALSE;
+   }
+
+   return TRUE;
+}
+
+void ArgvQuote(const std::wstring& Argument, std::wstring& CommandLine, bool Force){
+    if (Force == false &&
+        Argument.empty() == false &&
+        Argument.find_first_of(L" \t\n\v\"") == Argument.npos) {
+        CommandLine.append(Argument);
+    } else {
+        CommandLine.push_back(L'"');
+
+        for (auto It = Argument.begin();; ++It) {
+            unsigned NumberBackslashes = 0;
+
+            while (It != Argument.end() && *It == L'\\') {
+                ++It;
+                ++NumberBackslashes;
+            }
+
+            if (It == Argument.end()) {
+                // Escape all backslashes, but let the terminating
+                // double quotation mark we add below be interpreted
+                // as a metacharacter.
+                CommandLine.append(NumberBackslashes * 2, L'\\');
+                break;
+            } else if (*It == L'"') {
+                //
+                // Escape all backslashes and the following
+                // double quotation mark.
+                //
+                CommandLine.append(NumberBackslashes * 2 + 1, L'\\');
+                CommandLine.push_back(*It);
+            } else {
+                //
+                // Backslashes aren't special here.
+                //
+                CommandLine.append(NumberBackslashes, L'\\');
+                CommandLine.push_back(*It);
+            }
+        }
+
+        CommandLine.push_back(L'"');
+    }
+    CommandLine.push_back(L' ');
+}
+
+void LaunchApp() {
+    std::wstring cmdLine;
+
+    for (int i = 3; i < argCount; i++) {
+        if (!lstrcmp(szArgList[i], _T("$files"))) {
+            for (const auto& file : files) {
+                ArgvQuote(file, cmdLine, true);
+            }
+        } else if (!lstrcmp(szArgList[i], _T("--si-timeout"))) {
+            i++; // skip
+        }
+        else {
+            ArgvQuote(szArgList[i], cmdLine, true);
+        }
+    }
+    //MessageBox(0, cmdLine.c_str(), szArgList[2], 0);
+    HINSTANCE hinst =  ShellExecute(0, _T("open"), szArgList[2], cmdLine.c_str(), 0, SW_SHOWNORMAL);
+    if (reinterpret_cast<int>(hinst) <= 32) {
+        TCHAR buffer[256];
+        wsprintf(buffer, _T("ShellExecute failed. Error code=%d"), reinterpret_cast<int>(hinst));
+    }
+}
+
+LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
+{
+    int wmId, wmEvent;
+    PAINTSTRUCT ps;
+    HDC hdc;
+    COPYDATASTRUCT* pcds;
+
+    switch (message)
+    {
+    case WM_CREATE:
+        SetTimer(hWnd, TIMER_ID, timeout, 0);
+        break;
+    case WM_COPYDATA:
+        pcds = reinterpret_cast<COPYDATASTRUCT*>(lParam);
+        if (pcds->dwData == 1) {  
+            LPCTSTR lpszString = reinterpret_cast<LPCTSTR>(pcds->lpData);
+            files.push_back(lpszString);
+        }
+        break;
+    case WM_TIMER:
+        KillTimer(hWnd, TIMER_ID);
+        LaunchApp();
+        PostQuitMessage(0);
+        return 0;
+    case WM_DESTROY:
+        PostQuitMessage(0);
+        break;
+    default:
+        return DefWindowProc(hWnd, message, wParam, lParam);
+    }
+    return 0;
+}