JUCE: CallbackMessage Class Reference

JUCE

Public Member Functions | List of all members
CallbackMessage Class Referenceabstract
juce_events » messages

A message that invokes a callback method when it gets delivered. More...

`#include <juce_CallbackMessage.h>`

Inheritance diagram for CallbackMessage:

## Public Member Functions
| CallbackMessage ()=default
| ~CallbackMessage () override=default
| Destructor. More...
void | messageCallback () override=0
| Called when the message is delivered. More...
Public Member Functions inherited from MessageManager::MessageBase
| MessageBase ()=default
| ~MessageBase () override=default
virtual void | messageCallback ()=0
bool | post ()
Public Member Functions inherited from ReferenceCountedObject
void | incReferenceCount () noexcept
| Increments the object's reference count. More...
void | decReferenceCount () noexcept
| Decreases the object's reference count. More...
bool | decReferenceCountWithoutDeleting () noexcept
| Decreases the object's reference count. More...
int | getReferenceCount () const noexcept
| Returns the object's current reference count. More...

## Additional Inherited Members
Public Types inherited from MessageManager::MessageBase
using | Ptr = ReferenceCountedObjectPtr< MessageBase >
Protected Member Functions inherited from ReferenceCountedObject
| ReferenceCountedObject ()=default
| Creates the reference-counted object (with an initial ref count of zero). More...
| ReferenceCountedObject (const ReferenceCountedObject &) noexcept
| Copying from another object does not affect this one's reference-count. More...
| ReferenceCountedObject (ReferenceCountedObject &&) noexcept
| Copying from another object does not affect this one's reference-count. More...
ReferenceCountedObject & | operator= (const ReferenceCountedObject &) noexcept
| Copying from another object does not affect this one's reference-count. More...
ReferenceCountedObject & | operator= (ReferenceCountedObject &&) noexcept
| Copying from another object does not affect this one's reference-count. More...
virtual | ~ReferenceCountedObject ()
| Destructor. More...
void | resetReferenceCount () noexcept
| Resets the reference count to zero without deleting the object. More...

## Detailed Description

A message that invokes a callback method when it gets delivered.

You can use this class to fire off actions that you want to be performed later on the message thread.

To use it, create a subclass of CallbackMessage which implements the messageCallback() method, then call post() to dispatch it. The event thread will then invoke your messageCallback() method later on, and will automatically delete the message object afterwards.

Always create a new instance of a CallbackMessage on the heap, as it will be deleted automatically after the message has been delivered.

Note that this class was essential back in the days before C++11, but in modern times you may prefer to use MessageManager::callAsync() with a lambda.

See also
  MessageManager::callAsync, MessageListener, ActionListener, ChangeListener

## Constructor & Destructor Documentation

## ◆ CallbackMessage()

CallbackMessage::CallbackMessage | ( |  | ) |
| default

## ◆ ~CallbackMessage()

CallbackMessage::~CallbackMessage | ( |  | ) |
| overridedefault

Destructor.

## Member Function Documentation

## ◆ messageCallback()

void CallbackMessage::messageCallback | ( |  | ) |
| overridepure virtual

Called when the message is delivered.

You should implement this method and make it do whatever action you want to perform.

Note that like all other messages, this object will be deleted immediately after this method has been invoked.

Implements MessageManager::MessageBase.

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

- juce_CallbackMessage.h