Helpviewer/Network/QtHelpAccessHandler.py

# -*- coding: utf-8 -*-

# Copyright (c) 2009 - 2010 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a scheme access handler for QtHelp.
"""

import mimetypes
import os

from PyQt4.QtCore import QByteArray

from .SchemeAccessHandler import SchemeAccessHandler

from .NetworkReply import NetworkReply

QtDocPath = "qthelp://com.trolltech."

ExtensionMap = {
    ".bmp"   : "image/bmp",
    ".css"   : "text/css",
    ".gif"   : "image/gif",
    ".html"  : "text/html",
    ".htm"   : "text/html",
    ".ico"   : "image/x-icon",
    ".jpeg"  : "image/jpeg",
    ".jpg"   : "image/jpeg",
    ".js"    : "application/x-javascript",
    ".mng"   : "video/x-mng",
    ".pbm"   : "image/x-portable-bitmap",
    ".pgm"   : "image/x-portable-graymap",
    ".pdf"   : "application/pdf",
    ".png"   : "image/png",
    ".ppm"   : "image/x-portable-pixmap",
    ".rss"   : "application/rss+xml",
    ".svg"   : "image/svg+xml",
    ".svgz"  : "image/svg+xml",
    ".text"  : "text/plain",
    ".tif"   : "image/tiff",
    ".tiff"  : "image/tiff",
    ".txt"   : "text/plain",
    ".xbm"   : "image/x-xbitmap",
    ".xml"   : "text/xml",
    ".xpm"   : "image/x-xpm",
    ".xsl"   : "text/xsl",
    ".xhtml" : "application/xhtml+xml",
    ".wml"   : "text/vnd.wap.wml",
    ".wmlc"  : "application/vnd.wap.wmlc",
}

class QtHelpAccessHandler(SchemeAccessHandler):
    """
    Class implementing a scheme access handler for QtHelp.
    """
    def __init__(self, engine, parent = None):
        """
        Constructor
        
        @param engine reference to the help engine (QHelpEngine)
        @param parent reference to the parent object (QObject)
        """
        SchemeAccessHandler.__init__(self, parent)
        
        self.__engine = engine
    
    def __mimeFromUrl(self, url):
        """
        Private method to guess the mime type given an URL.
        
        @param url URL to guess the mime type from (QUrl)
        """
        path = url.path()
        ext = os.path.splitext(path)[1].lower()
        if ext in ExtensionMap:
            return ExtensionMap[ext]
        else:
            return "application/octet-stream"
    
    def createRequest(self, op, request, outgoingData = None):
        """
        Protected method to create a request.
        
        @param op the operation to be performed (QNetworkAccessManager.Operation)
        @param request reference to the request object (QNetworkRequest)
        @param outgoingData reference to an IODevice containing data to be sent
            (QIODevice)
        @return reference to the created reply object (QNetworkReply)
        """
        url = request.url()
        strUrl = url.toString()
        
        # For some reason the url to load is already wrong (passed from webkit)
        # though the css file and the references inside should work that way. One 
        # possible problem might be that the css is loaded at the same level as the
        # html, thus a path inside the css like (../images/foo.png) might cd out of
        # the virtual folder
        if not self.__engine.findFile(url).isValid():
            if strUrl.startswith(QtDocPath):
                newUrl = request.url()
                if not newUrl.path().startswith("/qdoc/"):
                    newUrl.setPath("qdoc" + newUrl.path())
                    url = newUrl
                    strUrl = url.toString()
        
        mimeType = mimetypes.guess_type(strUrl)[0]
        if mimeType is None:
            # do our own (limited) guessing
            mimeType = self.__mimeFromUrl(url)
        
        if self.__engine.findFile(url).isValid():
            data = self.__engine.fileData(url)
        else:
            data = QByteArray(self.trUtf8("""<title>Error 404...</title>"""
                """<div align="center"><br><br>"""
                """<h1>The page could not be found</h1><br>"""
                """<h3>'{0}'</h3></div>""").format(strUrl).encode("utf-8"))
        return NetworkReply(request, data, mimeType, self.parent())