Detailed Description

The module system is a very simple mechanism to allow applications (and parts of wxWidgets itself) to define initialization and cleanup functions that are automatically called on wxWidgets startup and exit.

To define a new kind of module, derive a class from wxModule, override the wxModule::OnInit and wxModule::OnExit functions, and add the wxDECLARE_DYNAMIC_CLASS and wxIMPLEMENT_DYNAMIC_CLASS to header and implementation files (which can be the same file). On initialization, wxWidgets will find all classes derived from wxModule, create an instance of each, and call each wxModule::OnInit function. On exit, wxWidgets will call the wxModule::OnExit function for each module instance.

Note that your module class does not have to be in a header file.

For example:

  // A module to allow DDE initialization/cleanup
// without calling these functions from app.cpp or from
// the user's application.
class wxDDEModule: public wxModule
{
public:
    wxDDEModule() { }
    virtual bool OnInit() { wxDDEInitialize(); return true; };
    virtual void OnExit() { wxDDECleanUp(); };
 
private:
    wxDECLARE_DYNAMIC_CLASS(wxDDEModule);
};
 
wxIMPLEMENT_DYNAMIC_CLASS(wxDDEModule, wxModule);
 
// Another module which uses DDE in its OnInit()
class MyModule: public wxModule
{
public:
    MyModule() { AddDependency(wxCLASSINFO(wxDDEModule)); }
    virtual bool OnInit() { ... code using DDE ... }
    virtual void OnExit() { ... }
 
private:
    wxDECLARE_DYNAMIC_CLASS(MyModule);
};
 
wxIMPLEMENT_DYNAMIC_CLASS(MyModule, wxModule);
 
// Another module which uses DDE in its OnInit()
// but uses a named dependency
class MyModule2: public wxModule
{
public:
    MyModule2() { AddDependency("wxDDEModule"); }
    virtual bool OnInit() { ... code using DDE ... }
    virtual void OnExit() { ... }
 
private:
    wxDECLARE_DYNAMIC_CLASS(MyModule2);
};
 
wxIMPLEMENT_DYNAMIC_CLASS(MyModule2, wxModule);

Library: wxBase

Category: Application and Process Management

Public Member Functions
	wxModule ()
	Constructs a wxModule object. More...

virtual	~wxModule ()
	Destructor. More...

virtual void	OnExit ()=0
	Provide this function with appropriate cleanup for your module. More...

virtual bool	OnInit ()=0
	Provide this function with appropriate initialization for your module. More...

Public Member Functions inherited from wxObject
	wxObject ()
	Default ctor; initializes to NULL the internal reference data. More...

	wxObject (const wxObject &other)
	Copy ctor. More...

virtual	~wxObject ()
	Destructor. More...

virtual wxClassInfo *	GetClassInfo () const
	This virtual function is redefined for every class that requires run-time type information, when using the wxDECLARE_CLASS macro (or similar). More...

wxObjectRefData *	GetRefData () const
	Returns the wxObject::m_refData pointer, i.e. the data referenced by this object. More...

bool	IsKindOf (const wxClassInfo *info) const
	Determines whether this class is a subclass of (or the same class as) the given class. More...

bool	IsSameAs (const wxObject &obj) const
	Returns true if this object has the same data pointer as obj. More...

void	Ref (const wxObject &clone)
	Makes this object refer to the data in clone. More...

void	SetRefData (wxObjectRefData *data)
	Sets the wxObject::m_refData pointer. More...

void	UnRef ()
	Decrements the reference count in the associated data, and if it is zero, deletes the data. More...

void	UnShare ()
	This is the same of AllocExclusive() but this method is public. More...

void	operator delete (void *buf)
	The delete operator is defined for debugging versions of the library only, when the identifier `__WXDEBUG__` is defined. More...

void *	operator new (size_t size, const wxString &filename=NULL, int lineNum=0)
	The new operator is defined for debugging versions of the library only, when the identifier `__WXDEBUG__` is defined. More...

Protected Member Functions
void	AddDependency (wxClassInfo *dep)
	Call this function from the constructor of the derived class. More...

void	AddDependency (const char *classname)
	Call this function from the constructor of the derived class. More...

Protected Member Functions inherited from wxObject
void	AllocExclusive ()
	Ensure that this object's data is not shared with any other object. More...

virtual wxObjectRefData *	CreateRefData () const
	Creates a new instance of the wxObjectRefData-derived class specific to this object and returns it. More...

virtual wxObjectRefData *	CloneRefData (const wxObjectRefData *data) const
	Creates a new instance of the wxObjectRefData-derived class specific to this object and initializes it copying data. More...

Additional Inherited Members
Protected Attributes inherited from wxObject
wxObjectRefData *	m_refData
	Pointer to an object which is the object's reference-counted data. More...

Constructor & Destructor Documentation

◆ wxModule()

wxModule::wxModule ( )

Constructs a wxModule object.

◆ ~wxModule()

virtual wxModule::~wxModule ( )

virtual

Destructor.

Member Function Documentation

◆ AddDependency() [1/2]

void wxModule::AddDependency ( const char * classname )

protected

Call this function from the constructor of the derived class.

This overload allows a dependency to be added by name without access to the class info.

This is useful when a module is declared entirely in a source file and there is no header for the declaration of the module needed by wxCLASSINFO(), however errors are not detected until run-time, instead of compile-time, then. Note that circular dependencies are detected and result in a fatal error.

Parameters

classname The class name of the dependent module.

◆ AddDependency() [2/2]

void wxModule::AddDependency ( wxClassInfo * dep )

protected

Call this function from the constructor of the derived class.

dep must be the wxCLASSINFO() of a wxModule-derived class and the corresponding module will be loaded before and unloaded after this module.

Parameters

dep	The class information object for the dependent module.

◆ OnExit()

virtual void wxModule::OnExit ( )

pure virtual

Provide this function with appropriate cleanup for your module.

◆ OnInit()

virtual bool wxModule::OnInit ( )

pure virtual

Provide this function with appropriate initialization for your module.

If the function returns false, wxWidgets will exit immediately.