GlobalVar< T > Class Template Reference

Wrapper for global variable, supports notification events when value changes. More...

#include <observable_globvar.h>

Inheritance diagram for GlobalVar< T >:

Public Member Functions
	GlobalVar (T *ptr)
	Create a GlobalVar using given pointer (variable address) as key. More...
void	Set (const T &arg)
	Set variable value and notify all listeners. More...
const T	Get ()
	Return current variable 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>
class GlobalVar< T >

Wrapper for global variable, supports notification events when value changes.

Client usage, writing a value + notifying listeners:

GlobalVar<wxString> compat_os(&g_compatOS);
compat_os.Set("ubuntu-gtk3-x86_64");

Client usage, modifying a value + notifying listeners:

GlobalVar<wxString> plugin_array_var(&plugin_array);
plugin_array.Add(new_pic);
plugin_array_var.Notify();

Client usage, listening to value changes:

class Foo: public wxEvtHandler {
public:
  Foo(...) {
    GlobalVar<wxString> compat_os(&g_compatOS);

    // compat_os sends a wxCommandEvent type EVT_FOO to this on change:
    wxDEFINE_EVENT(EVT_FOO, wxCommandEvent);
    compat_os_listener.Listen(compat_os, this, EVT_FOO);)

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

Definition at line 72 of file observable_globvar.h.

Constructor & Destructor Documentation

GlobalVar()

template<typename T >

GlobalVar< T >::GlobalVar ( T *  ptr )

inline

Create a GlobalVar using given pointer (variable address) as key.

Definition at line 75 of file observable_globvar.h.

Member Function Documentation

Get()

template<typename T >

const T GlobalVar< T >::Get ( )

inline

Return current variable value.

Definition at line 84 of file observable_globvar.h.

Set()

template<typename T >

void GlobalVar< T >::Set ( const T &  arg )

inline

Set variable value and notify all listeners.

Definition at line 78 of file observable_globvar.h.

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

• /home/mk/src/OpenCPN/libs/observable/include/observable_globvar.h