| Version: 3.3.1

Public Member Functions | List of all members
wxFileSystemWatcher Class Reference
Class List by Category » File Handling

`#include <wx/fswatcher.h>`

Inheritance diagram for wxFileSystemWatcher:
[legend]

## Detailed Description

The wxFileSystemWatcher class allows receiving notifications of file system changes.

Note
  Implementation limitations: this class is currently implemented for MSW, macOS and GTK ports but doesn't detect all changes correctly everywhere: under MSW accessing the file is not detected (only modifying it is) and under macOS neither accessing nor modifying is detected (only creating and deleting files is). Moreover, macOS version doesn't currently collapse pairs of create/delete events in a rename event, unlike the other ones.
  The application's event loop needs to be running before a wxFileSystemWatcher can be properly created, and that is why one should not be created too early during application startup. If you intend to create a wxFileSystemWatcher at startup, you can override wxAppConsole::OnEventLoopEnter() to ensure it is not done too early.

For the full list of change types that are reported see wxFSWFlags.

This class notifies the application about the file system changes by sending events of wxFileSystemWatcherEvent class. By default these events are sent to the wxFileSystemWatcher object itself so you can derive from it and use the event table `EVT_FSWATCHER` macro to handle these events in a derived class method. Alternatively, you can use wxFileSystemWatcher::SetOwner() to send the events to another object. Or you could use wxEvtHandler::Bind() with `wxEVT_FSWATCHER` to handle these events in any other object. See the fswatcher sample for an example of the latter approach.

##

Library: wxBase
Category: File Handling

Since
  2.9.1

## Public Member Functions
| wxFileSystemWatcher ()
| Default constructor. More...
virtual | ~wxFileSystemWatcher ()
| Destructor. More...
virtual bool | Add (const wxFileName &path, int events=wxFSW_EVENT_ALL)
| Adds path to currently watched files. More...
virtual bool | AddTree (const wxFileName &path, int events=wxFSW_EVENT_ALL, const wxString &filter=wxEmptyString)
| This is the same as Add(), but also recursively adds every file/directory in the tree rooted at path. More...
virtual bool | Remove (const wxFileName &path)
| Removes path from the list of watched paths. More...
virtual bool | RemoveTree (const wxFileName &path)
| This is the same as Remove(), but also removes every file/directory belonging to the tree rooted at path. More...
virtual bool | RemoveAll ()
| Clears the list of currently watched paths. More...
int | GetWatchedPathsCount () const
| Returns the number of currently watched paths. More...
int | GetWatchedPaths (wxArrayString *paths) const
| Retrieves all watched paths and places them in paths. More...
void | SetOwner (wxEvtHandler *handler)
| Associates the file system watcher with the given handler object. More...
Public Member Functions inherited from wxEvtHandler
| wxEvtHandler ()
| Constructor. More...
virtual | ~wxEvtHandler ()
| Destructor. More...
virtual void | QueueEvent (wxEvent *event)
| Queue event for a later processing. More...
virtual void | AddPendingEvent (const wxEvent &event)
| Post an event to be processed later. More...
template<typename T , typename T1 , ... >
void | CallAfter (void(T::*method)(T1,...), T1 x1,...)
| Asynchronously call the given method. More...
template<typename T >
void | CallAfter (const T &functor)
| Asynchronously call the given functor. More...
virtual bool | ProcessEvent (wxEvent &event)
| Processes an event, searching event tables and calling zero or more suitable event handler function(s). More...
bool | ProcessEventLocally (wxEvent &event)
| Try to process the event in this handler and all those chained to it. More...
bool | SafelyProcessEvent (wxEvent &event)
| Processes an event by calling ProcessEvent() and handles any exceptions that occur in the process. More...
void | ProcessPendingEvents ()
| Processes the pending events previously queued using QueueEvent() or AddPendingEvent(); you must call this function only if you are sure there are pending events for this handler, otherwise a `wxCHECK` will fail. More...
void | DeletePendingEvents ()
| Deletes all events queued on this event handler using QueueEvent() or AddPendingEvent(). More...
void | Connect (int id, int lastId, wxEventType eventType, wxObjectEventFunction function, wxObject *userData=nullptr, wxEvtHandler *eventSink=nullptr)
| Connects the given function dynamically with the event handler, id and event type. More...
void | Connect (int id, wxEventType eventType, wxObjectEventFunction function, wxObject *userData=nullptr, wxEvtHandler *eventSink=nullptr)
| See the Connect(int, int, wxEventType, wxObjectEventFunction, wxObject*, wxEvtHandler*) overload for more info. More...
void | Connect (wxEventType eventType, wxObjectEventFunction function, wxObject *userData=nullptr, wxEvtHandler *eventSink=nullptr)
| See the Connect(int, int, wxEventType, wxObjectEventFunction, wxObject*, wxEvtHandler*) overload for more info. More...
bool | Disconnect (wxEventType eventType, wxObjectEventFunction function, wxObject *userData=nullptr, wxEvtHandler *eventSink=nullptr)
| Disconnects the given function dynamically from the event handler, using the specified parameters as search criteria and returning true if a matching function has been found and removed. More...
bool | Disconnect (int id=wxID_ANY, wxEventType eventType=wxEVT_NULL, wxObjectEventFunction function=nullptr, wxObject *userData=nullptr, wxEvtHandler *eventSink=nullptr)
| See the Disconnect(wxEventType, wxObjectEventFunction, wxObject*, wxEvtHandler*) overload for more info. More...
bool | Disconnect (int id, int lastId, wxEventType eventType, wxObjectEventFunction function=nullptr, wxObject *userData=nullptr, wxEvtHandler *eventSink=nullptr)
| See the Disconnect(wxEventType, wxObjectEventFunction, wxObject*, wxEvtHandler*) overload for more info. More...
template<typename EventTag , typename Functor >
void | Bind (const EventTag &eventType, Functor functor, int id=wxID_ANY, int lastId=wxID_ANY, wxObject *userData=nullptr)
| Binds the given function, functor or method dynamically with the event. More...
template<typename EventTag , typename Class , typename EventArg , typename EventHandler >
void | Bind (const EventTag &eventType, void(Class::*method)(EventArg &), EventHandler *handler, int id=wxID_ANY, int lastId=wxID_ANY, wxObject *userData=nullptr)
| See the Bind<>(const EventTag&, Functor, int, int, wxObject*) overload for more info. More...
template<typename EventTag , typename Functor >
bool | Unbind (const EventTag &eventType, Functor functor, int id=wxID_ANY, int lastId=wxID_ANY, wxObject *userData=nullptr)
| Unbinds the given function, functor or method dynamically from the event handler, using the specified parameters as search criteria and returning true if a matching function has been found and removed. More...
template<typename EventTag , typename Class , typename EventArg , typename EventHandler >
bool | Unbind (const EventTag &eventType, void(Class::*method)(EventArg &), EventHandler *handler, int id=wxID_ANY, int lastId=wxID_ANY, wxObject *userData=nullptr)
| See the Unbind<>(const EventTag&, Functor, int, int, wxObject*) overload for more info. More...
void * | GetClientData () const
| Returns user-supplied client data. More...
wxClientData * | GetClientObject () const
| Returns a pointer to the user-supplied client data object. More...
void | SetClientData (void *data)
| Sets user-supplied client data. More...
void | SetClientObject (wxClientData *data)
| Set the client data object. More...
bool | GetEvtHandlerEnabled () const
| Returns true if the event handler is enabled, false otherwise. More...
wxEvtHandler * | GetNextHandler () const
| Returns the pointer to the next handler in the chain. More...
wxEvtHandler * | GetPreviousHandler () const
| Returns the pointer to the previous handler in the chain. More...
void | SetEvtHandlerEnabled (bool enabled)
| Enables or disables the event handler. More...
virtual void | SetNextHandler (wxEvtHandler *handler)
| Sets the pointer to the next handler. More...
virtual void | SetPreviousHandler (wxEvtHandler *handler)
| Sets the pointer to the previous handler. More...
void | Unlink ()
| Unlinks this event handler from the chain it's part of (if any); then links the "previous" event handler to the "next" one (so that the chain won't be interrupted). More...
bool | IsUnlinked () const
| Returns true if the next and the previous handler pointers of this event handler instance are nullptr. More...
Public Member Functions inherited from wxObject
| wxObject ()
| Default ctor; initializes to nullptr 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=nullptr, int lineNum=0)
| The new operator is defined for debugging versions of the library only, when the identifier `__WXDEBUG__` is defined. More...

## Additional Inherited Members
Static Public Member Functions inherited from wxEvtHandler
static void | AddFilter (wxEventFilter *filter)
| Add an event filter whose FilterEvent() method will be called for each and every event processed by wxWidgets. More...
static void | RemoveFilter (wxEventFilter *filter)
| Remove a filter previously installed with AddFilter(). More...
Protected Member Functions inherited from wxEvtHandler
virtual bool | TryBefore (wxEvent &event)
| Method called by ProcessEvent() before examining this object event tables. More...
virtual bool | TryAfter (wxEvent &event)
| Method called by ProcessEvent() as last resort. 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...
Protected Attributes inherited from wxObject
wxObjectRefData * | m_refData
| Pointer to an object which is the object's reference-counted data. More...

## Constructor & Destructor Documentation

## ◆ wxFileSystemWatcher()

wxFileSystemWatcher::wxFileSystemWatcher | ( |  | ) |

Default constructor.

## ◆ ~wxFileSystemWatcher()

virtual wxFileSystemWatcher::~wxFileSystemWatcher | ( |  | ) |
| virtual

Destructor.

Stops all paths from being watched and frees any system resources used by this file system watcher object.

## Member Function Documentation

## ◆ Add()

virtual bool wxFileSystemWatcher::Add | ( | const wxFileName & | path,
|  | int | events = `wxFSW_EVENT_ALL`
| ) |  |
| virtual

Adds path to currently watched files.

The path argument can currently only be a directory and any changes to this directory itself or its immediate children will generate the events. Use AddTree() to monitor the directory recursively.

Note that on platforms that use symbolic links, you should consider the possibility that path is a symlink. To watch the symlink itself and not its target you may call wxFileName::DontFollowLink() on path.

Parameters

  path | The name of the path to watch.
  events | An optional filter to receive only events of particular types. This is currently implemented only for GTK.

## ◆ AddTree()

virtual bool wxFileSystemWatcher::AddTree | ( | const wxFileName & | path,
|  | int | events = `wxFSW_EVENT_ALL`,
|  | const wxString & | filter = `wxEmptyString`
| ) |  |
| virtual

This is the same as Add(), but also recursively adds every file/directory in the tree rooted at path.

Additionally a file mask can be specified to include only files matching that particular mask.

This method is implemented efficiently on MSW and macOS, but should be used with care on other platforms for directories with lots of children (e.g. the root directory) as it calls Add() for each subdirectory, potentially creating a lot of watches and taking a long time to execute.

Note that on platforms that use symbolic links, you will probably want to have called wxFileName::DontFollowLink on path. This is especially important if the symlink targets may themselves be watched.

## ◆ GetWatchedPaths()

int wxFileSystemWatcher::GetWatchedPaths | ( | wxArrayString * | paths | ) | const

Retrieves all watched paths and places them in paths.

Returns the number of watched paths, which is also the number of entries added to paths.

## ◆ GetWatchedPathsCount()

int wxFileSystemWatcher::GetWatchedPathsCount | ( |  | ) | const

Returns the number of currently watched paths.

See also
  GetWatchedPaths()

## ◆ Remove()

virtual bool wxFileSystemWatcher::Remove | ( | const wxFileName & | path | ) |
| virtual

Removes path from the list of watched paths.

See the comment in Add() about symbolic links. path should treat symbolic links in the same way as in the original Add() call.

## ◆ RemoveAll()

virtual bool wxFileSystemWatcher::RemoveAll | ( |  | ) |
| virtual

Clears the list of currently watched paths.

## ◆ RemoveTree()

virtual bool wxFileSystemWatcher::RemoveTree | ( | const wxFileName & | path | ) |
| virtual

This is the same as Remove(), but also removes every file/directory belonging to the tree rooted at path.

See the comment in AddTree() about symbolic links. path should treat symbolic links in the same way as in the original AddTree() call.

## ◆ SetOwner()

void wxFileSystemWatcher::SetOwner | ( | wxEvtHandler * | handler | ) |

Associates the file system watcher with the given handler object.

All the events generated by this object will be passed to the specified owner.