JUCEApplication Class Reference

An instance of this class is used to specify initialisation and shutdown code for the application. More...

Inherits ApplicationCommandTarget, and ActionListener.

List of all members.

Public Member Functions
virtual	~JUCEApplication ()
	Destructor.
virtual void	initialise (const String &commandLineParameters)=0
	Called when the application starts.
bool	isInitialising () const throw ()
	Returns true if the application hasn't yet completed its initialise() method and entered the main event loop.
virtual void	shutdown ()=0
virtual const String	getApplicationName ()=0
	Returns the application's name.
virtual const String	getApplicationVersion ()
	Returns the application's version number.
virtual bool	moreThanOneInstanceAllowed ()
	Checks whether multiple instances of the app are allowed.
virtual void	anotherInstanceStarted (const String &commandLine)
	Indicates that the user has tried to start up another instance of the app.
virtual void	systemRequestedQuit ()
	Called when the operating system is trying to close the application.
virtual void	unhandledException (const std::exception *e, const String &sourceFilename, int lineNumber)
	If any unhandled exceptions make it through to the message dispatch loop, this callback will be triggered, in case you want to log them or do some other type of error-handling.
void	setApplicationReturnValue (int newReturnValue) throw ()
	Sets the value that should be returned as the application's exit code when the app quits.
int	getApplicationReturnValue () const throw ()
	Returns the value that has been set as the application's exit code.
const String	getCommandLineParameters () const throw ()
	Returns the application's command line params.
ApplicationCommandTarget *	getNextCommandTarget ()
void	getCommandInfo (CommandID commandID, ApplicationCommandInfo &result)
void	getAllCommands (Array< CommandID > &commands)
bool	perform (const InvocationInfo &info)
void	actionListenerCallback (const String &message)
bool	initialiseApp (String &commandLine)
Static Public Member Functions
static JUCEApplication *	getInstance () throw ()
	Returns the global instance of the application object being run.
static void	quit ()
	Signals that the main message loop should stop and the application should terminate.
static int	main (String &commandLine, JUCEApplication *newApp)
static int	main (int argc, const char *argv[], JUCEApplication *newApp)
static void	sendUnhandledException (const std::exception *e, const char *sourceFile, int lineNumber)
static int	shutdownAppAndClearUp ()
Protected Member Functions
	JUCEApplication ()
	Constructs a JUCE app object.

---

Detailed Description

An instance of this class is used to specify initialisation and shutdown code for the application.

An application that wants to run in the JUCE framework needs to declare a subclass of JUCEApplication and implement its various pure virtual methods.

It then needs to use the START_JUCE_APPLICATION macro somewhere in a cpp file to declare an instance of this class and generate a suitable platform-specific main() function.

e.g.

        class MyJUCEApp  : public JUCEApplication
        {
            // NEVER put objects inside a JUCEApplication class - only use pointers to
            // objects, which you must create in the initialise() method.
            MyApplicationWindow* myMainWindow;

        public:
            MyJUCEApp()
                : myMainWindow (0)
            {
                // never create any Juce objects in the constructor - do all your initialisation
                // in the initialise() method.
            }

            ~MyJUCEApp()
            {
                // all your shutdown code must have already been done in the shutdown() method -
                // nothing should happen in this destructor.
            }

            void initialise (const String& commandLine)
            {
                myMainWindow = new MyApplicationWindow();
                myMainWindow->setBounds (100, 100, 400, 500);
                myMainWindow->setVisible (true);
            }

            void shutdown()
            {
                delete myMainWindow;
            }

            const String getApplicationName()
            {
                return "Super JUCE-o-matic";
            }

            const String getApplicationVersion()
            {
                return "1.0";
            }
        };

        // this creates wrapper code to actually launch the app properly.
        START_JUCE_APPLICATION (MyJUCEApp)

Because this object will be created before Juce has properly initialised, you must NEVER add any member variable objects that will be automatically constructed. Likewise don't put ANY code in the constructor that could call Juce functions. Any objects that you want to add to the class must be pointers, which you should instantiate during the initialise() method, and delete in the shutdown() method.

See also:

MessageManager, DeletedAtShutdown

---

Constructor & Destructor Documentation

JUCEApplication::JUCEApplication

(

)

[protected]

Constructs a JUCE app object.

If subclasses implement a constructor or destructor, they shouldn't call any JUCE code in there - put your startup/shutdown code in initialise() and shutdown() instead.

virtual JUCEApplication::~JUCEApplication

(

)

[virtual]

Destructor.

If subclasses implement a constructor or destructor, they shouldn't call any JUCE code in there - put your startup/shutdown code in initialise() and shutdown() instead.

---

Member Function Documentation

static JUCEApplication* JUCEApplication::getInstance

(

)

throw () [static]

Returns the global instance of the application object being run.

virtual void JUCEApplication::initialise

(

const String &

commandLineParameters

)

[pure virtual]

Called when the application starts.

This will be called once to let the application do whatever initialisation it needs, create its windows, etc.

After the method returns, the normal event-dispatch loop will be run, until the quit() method is called, at which point the shutdown() method will be called to let the application clear up anything it needs to delete.

If during the initialise() method, the application decides not to start-up after all, it can just call the quit() method and the event loop won't be run.

Parameters:

commandLineParameters

the line passed in does not include the name of the executable, just the parameter list.

See also:

shutdown, quit

bool JUCEApplication::isInitialising

(

)

const throw ()

Returns true if the application hasn't yet completed its initialise() method and entered the main event loop.

This is handy for things like splash screens to know when the app's up-and-running properly.

virtual void JUCEApplication::shutdown

(

)

[pure virtual]

virtual const String JUCEApplication::getApplicationName

(

)

[pure virtual]

Returns the application's name.

An application must implement this to name itself.

virtual const String JUCEApplication::getApplicationVersion

(

)

[virtual]

Returns the application's version number.

An application can implement this to give itself a version. (The default implementation of this just returns an empty string).

virtual bool JUCEApplication::moreThanOneInstanceAllowed

(

)

[virtual]

Checks whether multiple instances of the app are allowed.

If you application class returns true for this, more than one instance is permitted to run (except on the Mac where this isn't possible).

If it's false, the second instance won't start, but it you will still get a callback to anotherInstanceStarted() to tell you about this - which gives you a chance to react to what the user was trying to do.

virtual void JUCEApplication::anotherInstanceStarted

(

const String &

commandLine

)

[virtual]

Indicates that the user has tried to start up another instance of the app.

This will get called even if moreThanOneInstanceAllowed() is false.

virtual void JUCEApplication::systemRequestedQuit

(

)

[virtual]

Called when the operating system is trying to close the application.

The default implementation of this method is to call quit(), but it may be overloaded to ignore the request or do some other special behaviour instead. For example, you might want to offer the user the chance to save their changes before quitting, and give them the chance to cancel.

If you want to send a quit signal to your app, this is the correct method to call, because it means that requests that come from the system get handled in the same way as those from your own application code. So e.g. you'd call this method from a "quit" item on a menu bar.

virtual void JUCEApplication::unhandledException	(	const std::exception *	e,
		const String &	sourceFilename,
		int	lineNumber
	)			[virtual]

If any unhandled exceptions make it through to the message dispatch loop, this callback will be triggered, in case you want to log them or do some other type of error-handling.

If the type of exception is derived from the std::exception class, the pointer passed-in will be valid. If the exception is of unknown type, this pointer will be null.

static void JUCEApplication::quit

(

)

[static]

Signals that the main message loop should stop and the application should terminate.

This isn't synchronous, it just posts a quit message to the main queue, and when this message arrives, the message loop will stop, the shutdown() method will be called, and the app will exit.

Note that this will cause an unconditional quit to happen, so if you need an extra level before this, e.g. to give the user the chance to save their work and maybe cancel the quit, you'll need to handle this in the systemRequestedQuit() method - see that method's help for more info.

See also:

MessageManager, DeletedAtShutdown

void JUCEApplication::setApplicationReturnValue

(

int

newReturnValue

)

throw ()

Sets the value that should be returned as the application's exit code when the app quits.

This is the value that's returned by the main() function. Normally you'd leave this as 0 unless you want to indicate an error code.

See also:

getApplicationReturnValue

int JUCEApplication::getApplicationReturnValue

(

)

const throw ()

Returns the value that has been set as the application's exit code.

See also:

setApplicationReturnValue

const String JUCEApplication::getCommandLineParameters

(

)

const throw ()

Returns the application's command line params.

static int JUCEApplication::main	(	String &	commandLine,
		JUCEApplication *	newApp
	)			[static]

For internal use only.

static int JUCEApplication::main	(	int	argc,
		const char *	argv[],
		JUCEApplication *	newApp
	)			[static]

For internal use only.

static void JUCEApplication::sendUnhandledException	(	const std::exception *	e,
		const char *	sourceFile,
		int	lineNumber
	)			[static]

For internal use only.

ApplicationCommandTarget* JUCEApplication::getNextCommandTarget

(

)

[virtual]

For internal use only.

Implements ApplicationCommandTarget.

void JUCEApplication::getCommandInfo	(	CommandID	commandID,
		ApplicationCommandInfo &	result
	)			[virtual]

For internal use only.

Implements ApplicationCommandTarget.

void JUCEApplication::getAllCommands

(

Array< CommandID > &

commands

)

[virtual]

For internal use only.

Implements ApplicationCommandTarget.

bool JUCEApplication::perform

(

const InvocationInfo &

info

)

[virtual]

For internal use only.

Implements ApplicationCommandTarget.

void JUCEApplication::actionListenerCallback

(

const String &

message

)

[virtual]

For internal use only.

Implements ActionListener.

bool JUCEApplication::initialiseApp

(

String &

commandLine

)

For internal use only.

static int JUCEApplication::shutdownAppAndClearUp

(

)

[static]

For internal use only.

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The documentation for this class was generated from the following file:

• juce_Application.h