JUCE/modules/juce_events/messages/juce_ApplicationBase.cpp

/*
  ==============================================================================

   This file is part of the JUCE library.
   Copyright (c) 2017 - ROLI Ltd.

   JUCE is an open source library subject to commercial or open-source
   licensing.

   The code included in this file is provided under the terms of the ISC license
   http://www.isc.org/downloads/software-support-policy/isc-license. Permission
   To use, copy, modify, and/or distribute this software for any purpose with or
   without fee is hereby granted provided that the above copyright notice and
   this permission notice appear in all copies.

   JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
   EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
   DISCLAIMED.

  ==============================================================================
*/

JUCEApplicationBase::CreateInstanceFunction JUCEApplicationBase::createInstance = 0;
JUCEApplicationBase* JUCEApplicationBase::appInstance = nullptr;

JUCEApplicationBase::JUCEApplicationBase()
    : appReturnValue (0),
      stillInitialising (true)
{
    jassert (isStandaloneApp() && appInstance == nullptr);
    appInstance = this;
}

JUCEApplicationBase::~JUCEApplicationBase()
{
    jassert (appInstance == this);
    appInstance = nullptr;
}

void JUCEApplicationBase::setApplicationReturnValue (const int newReturnValue) noexcept
{
    appReturnValue = newReturnValue;
}

// This is called on the Mac and iOS where the OS doesn't allow the stack to unwind on shutdown..
void JUCEApplicationBase::appWillTerminateByForce()
{
    JUCE_AUTORELEASEPOOL
    {
        {
            const ScopedPointer<JUCEApplicationBase> app (appInstance);

            if (app != nullptr)
                app->shutdownApp();
        }

        DeletedAtShutdown::deleteAll();
        MessageManager::deleteInstance();
    }
}

void JUCEApplicationBase::quit()
{
    MessageManager::getInstance()->stopDispatchLoop();
}

void JUCEApplicationBase::sendUnhandledException (const std::exception* const e,
                                                  const char* const sourceFile,
                                                  const int lineNumber)
{
    if (JUCEApplicationBase* const app = JUCEApplicationBase::getInstance())
    {
        // If you hit this assertion then the __FILE__ macro is providing a
        // relative path instead of an absolute path. On Windows this will be
        // a path relative to the build directory rather than the currently
        // running application. To fix this you must compile with the /FC flag.
        jassert (File::isAbsolutePath (sourceFile));

        app->unhandledException (e, sourceFile, lineNumber);
    }
}

//==============================================================================
#if ! (JUCE_IOS || JUCE_ANDROID)
 #define JUCE_HANDLE_MULTIPLE_INSTANCES 1
#endif

#if JUCE_HANDLE_MULTIPLE_INSTANCES
struct JUCEApplicationBase::MultipleInstanceHandler  : public ActionListener
{
public:
    MultipleInstanceHandler (const String& appName)
        : appLock ("juceAppLock_" + appName)
    {
    }

    bool sendCommandLineToPreexistingInstance()
    {
        if (appLock.enter (0))
            return false;

        JUCEApplicationBase* const app = JUCEApplicationBase::getInstance();
        jassert (app != nullptr);

        MessageManager::broadcastMessage (app->getApplicationName()
                                            + "/" + app->getCommandLineParameters());
        return true;
    }

    void actionListenerCallback (const String& message) override
    {
        if (JUCEApplicationBase* const app = JUCEApplicationBase::getInstance())
        {
            const String appName (app->getApplicationName());

            if (message.startsWith (appName + "/"))
                app->anotherInstanceStarted (message.substring (appName.length() + 1));
        }
    }

private:
    InterProcessLock appLock;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (MultipleInstanceHandler)
};

bool JUCEApplicationBase::sendCommandLineToPreexistingInstance()
{
    jassert (multipleInstanceHandler == nullptr); // this must only be called once!

    multipleInstanceHandler = new MultipleInstanceHandler (getApplicationName());
    return multipleInstanceHandler->sendCommandLineToPreexistingInstance();
}

#else
struct JUCEApplicationBase::MultipleInstanceHandler {};
#endif

//==============================================================================
#if JUCE_ANDROID

StringArray JUCEApplicationBase::getCommandLineParameterArray() { return {}; }
String JUCEApplicationBase::getCommandLineParameters()          { return {}; }

#else

#if JUCE_WINDOWS && ! defined (_CONSOLE)

String JUCE_CALLTYPE JUCEApplicationBase::getCommandLineParameters()
{
    return CharacterFunctions::findEndOfToken (CharPointer_UTF16 (GetCommandLineW()),
                                               CharPointer_UTF16 (L" "),
                                               CharPointer_UTF16 (L"\"")).findEndOfWhitespace();
}

StringArray JUCE_CALLTYPE JUCEApplicationBase::getCommandLineParameterArray()
{
    StringArray s;

    int argc = 0;
    if (LPWSTR* const argv = CommandLineToArgvW (GetCommandLineW(), &argc))
    {
        s = StringArray (argv + 1, argc - 1);
        LocalFree (argv);
    }

    return s;
}

#else

#if JUCE_IOS
 extern int juce_iOSMain (int argc, const char* argv[], void* classPtr);
#endif

#if JUCE_MAC
 extern void initialiseNSApplication();
#endif

#if JUCE_LINUX && JUCE_MODULE_AVAILABLE_juce_gui_extra && (! defined(JUCE_WEB_BROWSER) || JUCE_WEB_BROWSER)
 extern int juce_gtkWebkitMain (int argc, const char* argv[]);
#endif

#if JUCE_WINDOWS
 const char* const* juce_argv = nullptr;
 int juce_argc = 0;
#else
 extern const char* const* juce_argv;  // declared in juce_core
 extern int juce_argc;
#endif

String JUCEApplicationBase::getCommandLineParameters()
{
    String argString;

    for (int i = 1; i < juce_argc; ++i)
    {
        String arg (juce_argv[i]);

        if (arg.containsChar (' ') && ! arg.isQuotedString())
            arg = arg.quoted ('"');

        argString << arg << ' ';
    }

    return argString.trim();
}

StringArray JUCEApplicationBase::getCommandLineParameterArray()
{
    return StringArray (juce_argv + 1, juce_argc - 1);
}

int JUCEApplicationBase::main (int argc, const char* argv[], void* customDelegate)
{
    JUCE_AUTORELEASEPOOL
    {
        juce_argc = argc;
        juce_argv = argv;

       #if JUCE_MAC
        initialiseNSApplication();
       #endif

       #if JUCE_LINUX && JUCE_MODULE_AVAILABLE_juce_gui_extra && (! defined(JUCE_WEB_BROWSER) || JUCE_WEB_BROWSER)
        if (argc >= 2 && String (argv[1]) == "--juce-gtkwebkitfork-child")
            return juce_gtkWebkitMain (argc, argv);
       #endif

       #if JUCE_IOS
        return juce_iOSMain (argc, argv, customDelegate);
       #else
        ignoreUnused (customDelegate);

        return JUCEApplicationBase::main();
       #endif
    }
}

#endif

//==============================================================================
int JUCEApplicationBase::main()
{
    ScopedJuceInitialiser_GUI libraryInitialiser;
    jassert (createInstance != nullptr);

    const ScopedPointer<JUCEApplicationBase> app (createInstance());
    jassert (app != nullptr);

    if (! app->initialiseApp())
        return app->shutdownApp();

    JUCE_TRY
    {
        // loop until a quit message is received..
        MessageManager::getInstance()->runDispatchLoop();
    }
    JUCE_CATCH_EXCEPTION

    return app->shutdownApp();
}

#endif

//==============================================================================
bool JUCEApplicationBase::initialiseApp()
{
   #if JUCE_HANDLE_MULTIPLE_INSTANCES
    if ((! moreThanOneInstanceAllowed()) && sendCommandLineToPreexistingInstance())
    {
        DBG ("Another instance is running - quitting...");
        return false;
    }
   #endif

   #if JUCE_WINDOWS && JUCE_STANDALONE_APPLICATION && (! defined (_CONSOLE)) && (! JUCE_MINGW)
    if (AttachConsole (ATTACH_PARENT_PROCESS) != 0)
    {
        // if we've launched a GUI app from cmd.exe or PowerShell, we need this to enable printf etc.
        // However, only reassign stdout, stderr, stdin if they have not been already opened by
        // a redirect or similar.
        FILE* ignore;

        if (_fileno(stdout) < 0) freopen_s (&ignore, "CONOUT$", "w", stdout);
        if (_fileno(stderr) < 0) freopen_s (&ignore, "CONOUT$", "w", stderr);
        if (_fileno(stdin)  < 0) freopen_s (&ignore, "CONIN$",  "r", stdin);
    }
   #endif

    // let the app do its setting-up..
    initialise (getCommandLineParameters());

    stillInitialising = false;

    if (MessageManager::getInstance()->hasStopMessageBeenSent())
        return false;

   #if JUCE_HANDLE_MULTIPLE_INSTANCES
    if (multipleInstanceHandler != nullptr)
        MessageManager::getInstance()->registerBroadcastListener (multipleInstanceHandler);
   #endif

    return true;
}

int JUCEApplicationBase::shutdownApp()
{
    jassert (JUCEApplicationBase::getInstance() == this);

   #if JUCE_HANDLE_MULTIPLE_INSTANCES
    if (multipleInstanceHandler != nullptr)
        MessageManager::getInstance()->deregisterBroadcastListener (multipleInstanceHandler);
   #endif

    JUCE_TRY
    {
        // give the app a chance to clean up..
        shutdown();
    }
    JUCE_CATCH_EXCEPTION

    multipleInstanceHandler = nullptr;
    return getApplicationReturnValue();
}