ConfigVar< T > Class Template Reference

Wrapper for configuration variables which lives in a wxBaseConfig object. More...

#include <observable_confvar.h>

Inheritance diagram for ConfigVar< T >:

Public Member Functions
	ConfigVar (const std::string &section_, const std::string &key_, wxConfigBase *cb)
	Create a ConfigVar given section, key and a configuration. More...
void	Set (const T &arg)
	Set value to given argument and notify listeners. More...
const T	Get (const T &default_val)
	Get current value. More...
Public Member Functions inherited from Observable
	Observable (const std::string &_key)
	Create an instance listening to given key. More...
	Observable (const KeyProvider &kp)
	Create an instance listening to key provided by kp.GetKey(). More...
virtual const void	Notify ()
	Notify all listeners about variable change. More...
const void	Notify (std::shared_ptr< const void > p)
	Notify all listeners about variable change with a shared_ptr payload. More...
bool	Unlisten (wxEvtHandler *listener, wxEventType ev)
	Remove window listening to ev from list of listeners. More...
std::string	GetKey () const
	Retrieve the actual listening key: More...
virtual std::string	GetKey () const =0
	Return key used to listen and notify. More...

Additional Inherited Members
Public Attributes inherited from Observable
const std::string	key
	The key used to create and clone. More...
Protected Member Functions inherited from Observable
const void	Notify (std::shared_ptr< const void > ptr, const std::string &s, int num, void *client_data)
	Notify all listeners: send them a 'type' ObservedEvt message as defined by listen() with optional data available using GetString(), getInt(), GetSharedPtr() and/or GetClientData(). More...
const void	Notify (const std::string &s, void *client_data)
	Notify all listeners: send them a 'type' ObservedEvt message as defined by listen() with optional data available using GetString() and/or GetClientData(). More...

Detailed Description

template<typename T = std::string>
class ConfigVar< T >

Wrapper for configuration variables which lives in a wxBaseConfig object.

Supports int, bool, double, std::string and wxString. Besides basic set()/get() also provides notification events when value changes.

Client usage when reading, setting a value and notifying listeners:

ConfigVar<bool> expert("/PlugIns", "CatalogExpert", &g_pConfig);
bool old_value = expert.Get(false);
expert.Set(false);

Client usage, listening to value changes.

class Foo: public wxEventHandler {
public:
  Foo(...) {
    ConfigVar<bool> expert("/PlugIns", "CatalogExpert", &g_pConfig);

    // expert sends a wxCommandEvent of type EVT_FOO to this on change:
    wxDEFINE_EVENT(EVT_FOO, wxCommandEvent);
    expert_listener.Listen(expert, this, EVT_FOO);

    // Handle  EVT_FOO as any event when it arrives, for example:
    Bind(EVT_FOO,
         [](wxCommandEvent&) { cout << "value has changed"; });
    ...
  }
private:
  ObservableListener expert_listener;
  ...
}

Definition at line 69 of file observable_confvar.h.

Constructor & Destructor Documentation

ConfigVar()

template<typename T >

ConfigVar< T >::ConfigVar	(	const std::string &	section_,
		const std::string &	key_,
		wxConfigBase *	cb
	)

Create a ConfigVar given section, key and a configuration.

Definition at line 47 of file observable_confvar.cpp.

Member Function Documentation

Get()

template<typename T >

const T ConfigVar< T >::Get

(

const T &

default_val

)

Get current value.

Returns

value from configuration if it exists, else default_val

Definition at line 55 of file observable_confvar.cpp.

Set()

template<typename T >

void ConfigVar< T >::Set

(

const T &

arg

)

Set value to given argument and notify listeners.

Definition at line 66 of file observable_confvar.cpp.

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

• /home/mk/src/OpenCPN/libs/observable/include/observable_confvar.h
• /home/mk/src/OpenCPN/libs/observable/src/observable_confvar.cpp