wxFileSystemHandler Class Reference

#include <wx/filesys.h>

Inheritance diagram for wxFileSystemHandler:

Detailed Description

Classes derived from wxFileSystemHandler are used to access virtual file systems.

Its public interface consists of two methods: wxFileSystemHandler::CanOpen and wxFileSystemHandler::OpenFile.

It provides additional protected methods to simplify the process of opening the file: GetProtocol(), GetLeftLocation(), GetRightLocation(), GetAnchor(), GetMimeTypeFromExt().

Please have a look at overview (see wxFileSystem) if you don't know how locations are constructed.

Also consult the list of available handlers.

Note that the handlers are shared by all instances of wxFileSystem.

Remarks

wxHTML library provides handlers for local files and HTTP or FTP protocol.

Note

The location parameter passed to OpenFile() or CanOpen() methods is always an absolute path. You don't need to check the FS's current path.

wxPerl Note: In wxPerl, you need to derive your file system handler class from Wx::PlFileSystemHandler.

Library:  wxBase

Category:  Virtual File System

See Also

wxFileSystem, wxFSFile, wxFileSystem Overview

Public Member Functions
	wxFileSystemHandler ()
	Constructor.
virtual bool	CanOpen (const wxString &location)=0
	Returns true if the handler is able to open this file.
virtual wxString	FindFirst (const wxString &wildcard, int flags=0)
	Works like wxFindFirstFile().
virtual wxString	FindNext ()
	Returns next filename that matches parameters passed to wxFileSystem::FindFirst.
virtual wxFSFile *	OpenFile (wxFileSystem &fs, const wxString &location)=0
	Opens the file and returns wxFSFile pointer or NULL if failed.
Public Member Functions inherited from wxObject
	wxObject ()
	Default ctor; initializes to NULL the internal reference data.
	wxObject (const wxObject &other)
	Copy ctor.
virtual	~wxObject ()
	Destructor.
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).
wxObjectRefData *	GetRefData () const
	Returns the wxObject::m_refData pointer, i.e. the data referenced by this object.
bool	IsKindOf (const wxClassInfo *info) const
	Determines whether this class is a subclass of (or the same class as) the given class.
bool	IsSameAs (const wxObject &obj) const
	Returns true if this object has the same data pointer as obj.
void	Ref (const wxObject &clone)
	Makes this object refer to the data in clone.
void	SetRefData (wxObjectRefData *data)
	Sets the wxObject::m_refData pointer.
void	UnRef ()
	Decrements the reference count in the associated data, and if it is zero, deletes the data.
void	UnShare ()
	This is the same of AllocExclusive() but this method is public.
void	operator delete (void *buf)
	The delete operator is defined for debugging versions of the library only, when the identifier WXDEBUG is defined.
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.

Static Public Member Functions
static wxString	GetMimeTypeFromExt (const wxString &location)
	Returns the MIME type based on extension of location.

Static Protected Member Functions
static wxString	GetAnchor (const wxString &location)
	Returns the anchor if present in the location.
static wxString	GetLeftLocation (const wxString &location)
	Returns the left location string extracted from location.
static wxString	GetProtocol (const wxString &location)
	Returns the protocol string extracted from location.
static wxString	GetRightLocation (const wxString &location)
	Returns the right location string extracted from location.

Additional Inherited Members
Protected Member Functions inherited from wxObject
void	AllocExclusive ()
	Ensure that this object's data is not shared with any other object.
virtual wxObjectRefData *	CreateRefData () const
	Creates a new instance of the wxObjectRefData-derived class specific to this object and returns it.
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.
Protected Attributes inherited from wxObject
wxObjectRefData *	m_refData
	Pointer to an object which is the object's reference-counted data.

Constructor & Destructor Documentation

wxFileSystemHandler::wxFileSystemHandler

(

)

Constructor.

Member Function Documentation

virtual bool wxFileSystemHandler::CanOpen ( const wxString &  location )

pure virtual

Returns true if the handler is able to open this file.

This function doesn't check whether the file exists or not, it only checks if it knows the protocol. Example:

bool MyHand::CanOpen(const wxString& location)
{
    return (GetProtocol(location) == "http");
}

Must be overridden in derived handlers.

virtual wxString wxFileSystemHandler::FindFirst ( const wxString &  wildcard, int  flags = 0  )

virtual

Works like wxFindFirstFile().

Returns the name of the first filename (within filesystem's current path) that matches wildcard. flags may be one of wxFILE (only files), wxDIR (only directories) or 0 (both).

This method is only called if CanOpen() returns true.

virtual wxString wxFileSystemHandler::FindNext ( )

virtual

Returns next filename that matches parameters passed to wxFileSystem::FindFirst.

This method is only called if CanOpen() returns true and FindFirst() returned a non-empty string.

static wxString wxFileSystemHandler::GetAnchor ( const wxString &  location )

staticprotected

Returns the anchor if present in the location.

See wxFSFile::GetAnchor for details.

Example:

GetAnchor("index.htm#chapter2") == "chapter2"

Note

the anchor is NOT part of the left location.

static wxString wxFileSystemHandler::GetLeftLocation ( const wxString &  location )

staticprotected

Returns the left location string extracted from location.

Example:

GetLeftLocation("file:myzipfile.zip#zip:index.htm") == "file:myzipfile.zip"

static wxString wxFileSystemHandler::GetMimeTypeFromExt ( const wxString &  location )

static

Returns the MIME type based on extension of location.

(While wxFSFile::GetMimeType() returns real MIME type - either extension-based or queried from HTTP.)

Example:

GetMimeTypeFromExt("index.htm") == "text/html"

static wxString wxFileSystemHandler::GetProtocol ( const wxString &  location )

staticprotected

Returns the protocol string extracted from location.

Example:

GetProtocol("file:myzipfile.zip#zip:index.htm") == "zip"

static wxString wxFileSystemHandler::GetRightLocation ( const wxString &  location )

staticprotected

Returns the right location string extracted from location.

Example:

GetRightLocation("file:myzipfile.zip#zip:index.htm") == "index.htm"

virtual wxFSFile* wxFileSystemHandler::OpenFile ( wxFileSystem &  fs, const wxString &  location  )

pure virtual

Opens the file and returns wxFSFile pointer or NULL if failed.

Must be overridden in derived handlers.

Parameters

fs	Parent FS (the FS from that OpenFile was called). See the ZIP handler for details of how to use it.
location	The absolute location of file.