Helpviewer/Network/FtpReply.py

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

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

"""
Module implementing a network reply class for FTP resources.
"""

from PyQt4.QtCore import QByteArray, QIODevice, Qt, QUrl, QTimer, QBuffer
from PyQt4.QtGui import QPixmap
from PyQt4.QtNetwork import QFtp, QNetworkReply, QNetworkRequest, QUrlInfo
from PyQt4.QtWebKit import QWebSettings

import UI.PixmapCache

ftpListPage_html = """\
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<title>{0}</title>
<style type="text/css">
body {{
  padding: 3em 0em;
  background: -webkit-gradient(linear, left top, left bottom, from(#85784A), to(#FDFDFD), color-stop(0.5, #FDFDFD));
  background-repeat: repeat-x;
}}
#box {{
  background: white;
  border: 1px solid #85784A;
  width: 80%;
  padding: 30px;
  margin: auto;
  -webkit-border-radius: 0.8em;
}}
h1 {{
  font-size: 130%;
  font-weight: bold;
  border-bottom: 1px solid #85784A;
}}
th {{
  background-color: #B8B096;
  color: black;
}}
table {{
  border: solid 1px #85784A;
  margin: 5px 0;
  width: 100%;
}}
tr.odd {{
  background-color: white;
  color: black;
}}
tr.even {{
  background-color: #CEC9B8;
  color: black;
}}
.modified {{
  text-align: left;
  vertical-align: top;
  white-space: nowrap;
}}
.size {{
  text-align: right;
  vertical-align: top;
  white-space: nowrap;
  padding-right: 22px;
}}
.name {{
  text-align: left;
  vertical-align: top;
  white-space: pre-wrap;
  width: 100%
}}
{1}
</style>
</head>
<body>
  <div id="box">
  <h1>{2}</h1>
{3}
  <table align="center" cellspacing="0" width="90%">
{4}
  </table>
  </div>
</body>
</html>
"""

class FtpReply(QNetworkReply):
    """
    Class implementing a network reply for FTP resources.
    """
    def __init__(self, url, parent = None):
        """
        Constructor
        
        @param url requested FTP URL (QUrl)
        @param parent reference to the parent object (QObject)
        """
        QNetworkReply.__init__(self, parent)
        
        self.__ftp = QFtp(self)
        self.__ftp.listInfo.connect(self.__processListInfo)
        self.__ftp.readyRead.connect(self.__processData)
        self.__ftp.commandFinished.connect(self.__processCommand)
        self.__ftp.commandStarted.connect(self.__commandStarted)
        self.__ftp.dataTransferProgress.connect(self.downloadProgress)
        
        self.__items = []
        self.__content = QByteArray()
        self.__units = ["Bytes", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"]
        
        self.setUrl(url)
        QTimer.singleShot(0, self.__connectToHost)
    
    def abort(self):
        """
        Public slot to abort the operation.
        """
        # do nothing
        pass
    
    def bytesAvailable(self):
        """
        Public method to determined the bytes available for being read.
        
        @return bytes available (integer)
        """
        return self.__content.size()
    
    def isSequential(self):
        """
        Public method to check for sequential access.
        
        @return flag indicating sequential access (boolean)
        """
        return True
    
    def readData(self, maxlen):
        """
        Protected method to retrieve data from the reply object.
        
        @param maxlen maximum number of bytes to read (integer)
        @return string containing the data (bytes)
        """
        if self.__content.size():
            len_ = min(maxlen, self.__content.size())
            buffer = bytes(self.__content[:len_])
            self.__content.remove(0, len_)
            return buffer
    
    def __connectToHost(self):
        """
        Private slot to start the FTP process by connecting to the host.
        """
        self.__ftp.connectToHost(self.url().host())
    
    def __commandStarted(self, id):
        """
        Private slot to handle the start of FTP commands.
        
        @param id id of the command to be processed (integer) (ignored)
        """
        cmd = self.__ftp.currentCommand()
        if cmd == QFtp.Get:
            self.__setContent()
    
    def __processCommand(self, id, error):
        """
        Private slot to handle the end of FTP commands.
        
        @param id id of the command to be processed (integer) (ignored)
        @param error flag indicating an error condition (boolean)
        """
        if error:
            if error == QFtp.HostNotFound:
                err = QNetworkReply.HostNotFoundError
            elif error == QFtp.ConnectionRefused:
                err = QNetworkReply.ConnectionRefusedError
            else:
                err = QNetworkReply.ContentNotFoundError
            self.setError(err, self.__ftp.errorString())
            self.error.emit(err)
            return
        
        cmd = self.__ftp.currentCommand()
        if cmd == QFtp.ConnectToHost:
            self.__ftp.login()
        elif cmd == QFtp.Login:
            self.__ftp.list(self.url().path())
        elif cmd == QFtp.List:
            if len(self.__items) == 1 and \
               self.__items[0].isFile():
                self.__ftp.get(self.url().path())
            else:
                self.__setListContent()
        elif cmd == QFtp.Get:
            self.finished.emit()
            self.__ftp.close()
    
    def __processListInfo(self, urlInfo):
        """
        Private slot to process list information from the FTP server.
        
        @param urlInfo reference to the information object (QUrlInfo)
        """
        self.__items.append(QUrlInfo(urlInfo))
    
    def __processData(self):
        """
        Private slot to process data from the FTP server.
        """
        self.__content += self.__ftp.readAll()
        self.readyRead.emit()
    
    def __setContent(self):
        """
        Private method to set the finish the setup of the data.
        """
        self.open(QIODevice.ReadOnly | QIODevice.Unbuffered)
        self.setHeader(QNetworkRequest.ContentLengthHeader, self.__items[0].size())
        self.setAttribute(QNetworkRequest.HttpStatusCodeAttribute, 200)
        self.setAttribute(QNetworkRequest.HttpReasonPhraseAttribute, "Ok")
        self.metaDataChanged.emit()
    
    def __cssLinkClass(self, icon, size = 32):
        """
        Private method to generate a link class with an icon.
        
        @param icon icon to be included (QIcon)
        @param size size of the icon to be generated (integer)
        @return CSS class string (string)
        """
        cssString = \
            """a.{{0}} {{{{\n"""\
            """  padding-left: {0}px;\n"""\
            """  background: transparent url(data:image/png;base64,{1}) no-repeat center left;\n"""\
            """  font-weight: bold;\n"""\
            """}}}}\n"""
        pixmap = icon.pixmap(size, size)
        imageBuffer = QBuffer()
        imageBuffer.open(QIODevice.ReadWrite)
        if not pixmap.save(imageBuffer, "PNG"):
            # write a blank pixmap on error
            pixmap = QPixmap(size, size)
            pixmap.fill(Qt.transparent)
            imageBuffer.buffer().clear()
            pixmap.save(imageBuffer, "PNG")
        return cssString.format(size + 4, 
            str(imageBuffer.buffer().toBase64(), encoding="ascii"))
    
    def __setListContent(self):
        """
        Private method to prepare the content for the reader.
        """
        u = self.url()
        if not u.path().endswith("/"):
            u.setPath(u.path() + "/")
        
        baseUrl = self.url().toString()
        basePath = u.path()
        
        linkClasses = {}
        iconSize = QWebSettings.globalSettings().fontSize(QWebSettings.DefaultFontSize);
        
        parent = u.resolved(QUrl(".."))
        if parent.isParentOf(u):
            icon = UI.PixmapCache.getIcon("up.png")
            linkClasses["link_parent"] = \
                self.__cssLinkClass(icon, iconSize).format("link_parent")
            parentStr = self.trUtf8(
                """  <p><a class="link_parent" href="{0}">"""
                """Change to parent directory</a></p>"""
            ).format(parent.toString())
        else:
            parentStr = ""
        
        row = \
            """    <tr class="{0}">"""\
            """<td class="name"><a class="{1}" href="{2}">{3}</a></td>"""\
            """<td class="size">{4}</td>"""\
            """<td class="modified">{5}</td>"""\
            """</tr>\n"""
        table = self.trUtf8(
            """    <tr>"""
            """<th align="left">Name</th>"""
            """<th>Size</th>"""
            """<th align="left">Last modified</th>"""
            """</tr>\n"""
        )
        
        i = 0
        for item in self.__items:
            name = item.name()
            if item.isDir() and not name.endswith("/"):
                name += "/"
            child = u.resolved(QUrl(name.replace(":", "%3A")))
            
            if item.isFile():
                size = item.size()
                unit = 0
                while size:
                    newSize = size // 1024
                    if newSize and unit < len(self.__units):
                        size = newSize
                        unit += 1
                    else:
                        break
                
                sizeStr = self.trUtf8("{0} {1}", "size unit")\
                    .format(size, self.__units[unit])
                linkClass = "link_file"
                if linkClass not in linkClasses:
                    icon = UI.PixmapCache.getIcon("fileMisc.png")
                    linkClasses[linkClass] = \
                        self.__cssLinkClass(icon, iconSize).format(linkClass)
            else:
                sizeStr = ""
                linkClass = "link_dir"
                if linkClass not in linkClasses:
                    icon = UI.PixmapCache.getIcon("dirClosed.png")
                    linkClasses[linkClass] = \
                        self.__cssLinkClass(icon, iconSize).format(linkClass)
            table += row.format(
                i == 0 and "odd" or "even",
                linkClass, 
                child.toString(), 
                Qt.escape(item.name()), 
                sizeStr,
                item.lastModified().toString("yyyy-MM-dd hh:mm"), 
            )
            i = 1 - i
        
        content = ftpListPage_html.format(
            Qt.escape(baseUrl), 
            "".join(linkClasses.values()), 
            self.trUtf8("Listing of {0}").format(basePath), 
            parentStr, 
            table
        )
        self.__content = QByteArray(content.encode("utf8"))
        
        self.open(QIODevice.ReadOnly | QIODevice.Unbuffered)
        self.setHeader(QNetworkRequest.ContentTypeHeader, "text/html; charset=UTF-8")
        self.setHeader(QNetworkRequest.ContentLengthHeader, self.__content.size())
        self.setAttribute(QNetworkRequest.HttpStatusCodeAttribute, 200)
        self.setAttribute(QNetworkRequest.HttpReasonPhraseAttribute, "Ok")
        self.metaDataChanged.emit()
        self.downloadProgress.emit(self.__content.size(), self.__content.size())
        self.readyRead.emit()
        self.finished.emit()
        self.__ftp.close()