This class is in charge of the application's event-dispatch loop. More...

#include "juce_MessageManager.h"

Classes
class	Lock
	A lock you can use to lock the message manager. More...

class	MessageBase
	Internal class used as the base class for all message objects. More...

class	QuitMessage

Public Member Functions
void	runDispatchLoop ()
	Runs the event dispatch loop until a stop message is posted.

void	stopDispatchLoop ()
	Sends a signal that the dispatch loop should terminate.

bool	hasStopMessageBeenSent () const noexcept
	Returns true if the stopDispatchLoop() method has been called.

void *	callFunctionOnMessageThread (MessageCallbackFunction callback, void userData)
	Calls a function using the message-thread.

bool	isThisTheMessageThread () const noexcept
	Returns true if the caller-thread is the message thread.

void	setCurrentThreadAsMessageThread ()
	Called to tell the manager that the current thread is the one that's running the dispatch loop.

Thread::ThreadID	getCurrentMessageThread () const noexcept
	Returns the ID of the current message thread, as set by setCurrentThreadAsMessageThread().

bool	currentThreadHasLockedMessageManager () const noexcept
	Returns true if the caller thread has currently got the message manager locked.

void	registerBroadcastListener (ActionListener *listener)
	Registers a listener to get told about broadcast messages.

void	deregisterBroadcastListener (ActionListener *listener)
	Deregisters a broadcast listener.

Static Public Member Functions
static MessageManager *	getInstance ()
	Returns the global instance of the MessageManager.

static MessageManager *	getInstanceWithoutCreating () noexcept
	Returns the global instance of the MessageManager, or nullptr if it doesn't exist.

static void	deleteInstance ()
	Deletes the global MessageManager instance.

static bool	callAsync (std::function< void()> functionToCall)
	Asynchronously invokes a function or C++11 lambda on the message thread.

static bool	existsAndIsLockedByCurrentThread () noexcept
	Returns true if there's an instance of the MessageManager, and if the current thread has the lock on it.

static bool	existsAndIsCurrentThread () noexcept
	Returns true if there's an instance of the MessageManager, and if the current thread is running it.

static void	broadcastMessage (const String &messageText)
	Sends a message to all other JUCE applications that are running.

Friends
class	MessageBase

class	QuitMessage

class	MessageManagerLock

Detailed Description

This class is in charge of the application's event-dispatch loop.

See also: Message, CallbackMessage, MessageManagerLock, JUCEApplication, JUCEApplicationBase

@tags{Events}

Definition at line 44 of file juce_MessageManager.h.

Member Function Documentation

◆ broadcastMessage()

void juce::MessageManager::broadcastMessage ( const String & messageText )

static

Sends a message to all other JUCE applications that are running.

Parameters

messageText the string that will be passed to the actionListenerCallback() method of the broadcast listeners in the other app.

See also: registerBroadcastListener, ActionListener

Definition at line 325 of file juce_Messaging_linux.cpp.

◆ callAsync()

bool juce::MessageManager::callAsync ( std::function< void()> functionToCall )

static

Asynchronously invokes a function or C++11 lambda on the message thread.

Returns: true if the message was successfully posted to the message queue, or false otherwise.

Definition at line 195 of file juce_MessageManager.cpp.

◆ callFunctionOnMessageThread()

void * juce::MessageManager::callFunctionOnMessageThread	(	MessageCallbackFunction *	callback,
		void *	userData
	)

Calls a function using the message-thread.

This can be used by any thread to cause this function to be called-back by the message thread. If it's the message-thread that's calling this method, then the function will just be called; if another thread is calling, a message will be posted to the queue, and this method will block until that message is delivered, the function is called, and the result is returned.

Be careful not to cause any deadlocks with this! It's easy to do - e.g. if the caller thread has a critical section locked, which an unrelated message callback then tries to lock before the message thread gets round to processing this callback.

Parameters

callback	the function to call - its signature must be void* myCallbackFunction (void) juce::unalignedPointerCast Type unalignedPointerCast(void ptr) noexcept Casts a pointer to another type via void, which suppresses the cast-align warning which sometimes ar... Definition* juce_Memory.h:88
userData	a user-defined pointer that will be passed to the function that gets called

Returns: the value that the callback function returns.

See also: MessageManagerLock

Definition at line 175 of file juce_MessageManager.cpp.

◆ currentThreadHasLockedMessageManager()

bool juce::MessageManager::currentThreadHasLockedMessageManager ( ) const

noexcept

Returns true if the caller thread has currently got the message manager locked.

see the MessageManagerLock class for more info about this.

This will be true if the caller is the message thread, because that automatically gains a lock while a message is being dispatched.

Definition at line 252 of file juce_MessageManager.cpp.

◆ deleteInstance()

void juce::MessageManager::deleteInstance ( )

static

Deletes the global MessageManager instance.

Does nothing if no instance had been created.

Definition at line 63 of file juce_MessageManager.cpp.

◆ deregisterBroadcastListener()

void juce::MessageManager::deregisterBroadcastListener ( ActionListener * listener )

Deregisters a broadcast listener.

Definition at line 222 of file juce_MessageManager.cpp.

◆ existsAndIsCurrentThread()

bool juce::MessageManager::existsAndIsCurrentThread ( )

staticnoexcept

Returns true if there's an instance of the MessageManager, and if the current thread is running it.

Definition at line 266 of file juce_MessageManager.cpp.

◆ existsAndIsLockedByCurrentThread()

bool juce::MessageManager::existsAndIsLockedByCurrentThread ( )

staticnoexcept

Returns true if there's an instance of the MessageManager, and if the current thread has the lock on it.

Definition at line 258 of file juce_MessageManager.cpp.

◆ getCurrentMessageThread()

Thread::ThreadID juce::MessageManager::getCurrentMessageThread ( ) const

noexcept

Returns the ID of the current message thread, as set by setCurrentThreadAsMessageThread().

(Best to ignore this method unless you really know what you're doing..)

See also: setCurrentThreadAsMessageThread

Definition at line 134 of file juce_MessageManager.h.

◆ getInstance()

MessageManager * juce::MessageManager::getInstance ( )

static

Returns the global instance of the MessageManager.

Definition at line 47 of file juce_MessageManager.cpp.

◆ getInstanceWithoutCreating()

MessageManager * juce::MessageManager::getInstanceWithoutCreating ( )

staticnoexcept

Returns the global instance of the MessageManager, or nullptr if it doesn't exist.

Definition at line 58 of file juce_MessageManager.cpp.

◆ hasStopMessageBeenSent()

bool juce::MessageManager::hasStopMessageBeenSent ( ) const

noexcept

Returns true if the stopDispatchLoop() method has been called.

Definition at line 80 of file juce_MessageManager.h.

◆ isThisTheMessageThread()

bool juce::MessageManager::isThisTheMessageThread ( ) const

noexcept

Returns true if the caller-thread is the message thread.

Definition at line 229 of file juce_MessageManager.cpp.

◆ registerBroadcastListener()

void juce::MessageManager::registerBroadcastListener ( ActionListener * listener )

Registers a listener to get told about broadcast messages.

The actionListenerCallback() callback's string parameter is the message passed into broadcastMessage().

See also: broadcastMessage

Definition at line 214 of file juce_MessageManager.cpp.

◆ runDispatchLoop()

void juce::MessageManager::runDispatchLoop ( )

Runs the event dispatch loop until a stop message is posted.

This method is only intended to be run by the application's startup routine, as it blocks, and will only return after the stopDispatchLoop() method has been used.

See also: stopDispatchLoop

Definition at line 104 of file juce_MessageManager.cpp.

◆ setCurrentThreadAsMessageThread()

void juce::MessageManager::setCurrentThreadAsMessageThread ( )

Called to tell the manager that the current thread is the one that's running the dispatch loop.

(Best to ignore this method unless you really know what you're doing..)

See also: getCurrentMessageThread

Definition at line 236 of file juce_MessageManager.cpp.

◆ stopDispatchLoop()

void juce::MessageManager::stopDispatchLoop ( )

Sends a signal that the dispatch loop should terminate.

After this is called, the runDispatchLoop() or runDispatchLoopUntil() methods will be interrupted and will return.

See also: runDispatchLoop

Definition at line 119 of file juce_MessageManager.cpp.

Friends And Related Symbol Documentation

◆ MessageBase

friend class MessageBase

friend

Definition at line 332 of file juce_MessageManager.h.

◆ MessageManagerLock

friend class MessageManagerLock

friend

Definition at line 335 of file juce_MessageManager.h.

◆ QuitMessage

friend class QuitMessage

friend

Definition at line 334 of file juce_MessageManager.h.

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

juce_events/messages/juce_MessageManager.h
juce_events/messages/juce_MessageManager.cpp
juce_events/native/juce_Messaging_linux.cpp

Classes

Public Member Functions

Static Public Member Functions

Friends

Detailed Description

Member Function Documentation

◆ broadcastMessage()

◆ callAsync()

◆ callFunctionOnMessageThread()

◆ currentThreadHasLockedMessageManager()

◆ deleteInstance()

◆ deregisterBroadcastListener()

◆ existsAndIsCurrentThread()

◆ existsAndIsLockedByCurrentThread()

◆ getCurrentMessageThread()

◆ getInstance()

◆ getInstanceWithoutCreating()

◆ hasStopMessageBeenSent()

◆ isThisTheMessageThread()

◆ registerBroadcastListener()

◆ runDispatchLoop()

◆ setCurrentThreadAsMessageThread()

◆ stopDispatchLoop()

Friends And Related Symbol Documentation

◆ MessageBase

◆ MessageManagerLock

◆ QuitMessage