wxFSFile Class Reference

#include </home/zeitlin/src/wx/github/interface/wx/filesys.h>

Inheritance diagram for wxFSFile:

---

Detailed Description

This class represents a single file opened by wxFileSystem.

It provides more informations than wxWidgets' input streams (stream, filename, mime type, anchor).

注:

Any pointer returned by a method of wxFSFile is valid only as long as the wxFSFile object exists. For example a call to GetStream() doesn't create the stream but only returns the pointer to it. In other words after 10 calls to GetStream() you will have obtained ten identical pointers.

Library:  wxBase

Category:  Virtual File System, File Handling

参照:

wxFileSystemHandler, wxFileSystem, wxFileSystem Overview

Public Member Functions
	wxFSFile (wxInputStream *stream, const wxString &location, const wxString &mimetype, const wxString &anchor, wxDateTime modif)
	Constructor.
wxInputStream *	DetachStream ()
	Detaches the stream from the wxFSFile object.
const wxString &	GetAnchor () const
	Returns anchor (if present).
const wxString &	GetLocation () const
	Returns full location of the file, including path and protocol.
const wxString &	GetMimeType () const
	Returns the MIME type of the content of this file.
wxDateTime	GetModificationTime () const
	Returns time when this file was modified.
wxInputStream *	GetStream () const
	Returns pointer to the stream.

List of all members.

---

Constructor & Destructor Documentation

wxFSFile::wxFSFile	(	wxInputStream *	stream,
		const wxString &	location,
		const wxString &	mimetype,
		const wxString &	anchor,
		wxDateTime	modif
	)

Constructor.

You probably won't use it. See the Note for details.

It is seldom used by the application programmer but you will need it if you are writing your own virtual FS. For example you may need something similar to wxMemoryInputStream, but because wxMemoryInputStream doesn't free the memory when destroyed and thus passing a memory stream pointer into wxFSFile constructor would lead to memory leaks, you can write your own class derived from wxFSFile:

        class wxMyFSFile : public wxFSFile
        {
            private:
                void *m_Mem;
            public:
                wxMyFSFile(.....)
                ~wxMyFSFile() {free(m_Mem);}
                    // of course dtor is virtual ;-)
        };

If you are not sure of the meaning of these params, see the description of the GetXXXX() functions.

Parameters:

stream	The input stream that will be used to access data
location	The full location (aka filename) of the file
mimetype	MIME type of this file. It may be left empty, in which case the type will be determined from file's extension (location must not be empty in this case).
anchor	Anchor. See GetAnchor() for details.
modif	Modification date and time for this file.

---

Member Function Documentation

wxInputStream* wxFSFile::DetachStream

(

)

Detaches the stream from the wxFSFile object.

That is, the stream obtained with GetStream() will continue its existence after the wxFSFile object is deleted.

You will have to delete the stream yourself.

const wxString& wxFSFile::GetAnchor

(

)

const

Returns anchor (if present).

The term of anchor can be easily explained using few examples:

        index.htm#anchor                      // 'anchor' is anchor
        index/wx001.htm                       // NO anchor here!        archive/main.zip#zip:index.htm#global // 'global'
        archive/main.zip#zip:index.htm        // NO anchor here!
        

Usually an anchor is presented only if the MIME type is 'text/html'. But it may have some meaning with other files; for example myanim.avi#200 may refer to position in animation or reality.wrl::MyView may refer to a predefined view in VRML.

const wxString& wxFSFile::GetLocation

(

)

const

Returns full location of the file, including path and protocol.

Examples:

        http://www.wxwidgets.org
        http://www.ms.mff.cuni.cz/~vsla8348/wxhtml/archive.zip#zip:info.txt
        file:/home/vasek/index.htm
        relative-file.htm
        

const wxString& wxFSFile::GetMimeType

(

)

const

Returns the MIME type of the content of this file.

It is either extension-based (see wxMimeTypesManager) or extracted from HTTP protocol Content-Type header.

wxDateTime wxFSFile::GetModificationTime

(

)

const

Returns time when this file was modified.

wxInputStream* wxFSFile::GetStream

(

)

const

Returns pointer to the stream.

You can use the returned stream to directly access data. You may suppose that the stream provide Seek and GetSize functionality (even in the case of the HTTP protocol which doesn't provide this by default. wxHtml uses local cache to work around this and to speed up the connection).