Helpviewer/Network/FileReply.py

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

# Copyright (c) 2012 Detlev Offenbach <detlev@die-offenbachs.de>
#

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

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

import UI.PixmapCache


dirListPage_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 FileReply(QNetworkReply):
    """
    Class implementing a network reply for directory resources.
    """
    def __init__(self, url, parent=None):
        """
        Constructor
        
        @param url requested FTP URL (QUrl)
        @param parent reference to the parent object (QObject)
        """
        super().__init__(parent)
        
        self.__content = QByteArray()
        self.__units = ["Bytes", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"]
        
        if url.path() == "":
            url.setPath("/")
        self.setUrl(url)
        
        QTimer.singleShot(0, self.__loadDirectory)
    
    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 __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 __loadDirectory(self):
        """
        Private slot loading the directory and preparing the listing page.
        """
        dir = QDir(self.url().toLocalFile())
        dirItems = dir.entryInfoList(QDir.AllEntries | QDir.Hidden | QDir.NoDotAndDotDot,
                                     QDir.Name | QDir.DirsFirst)
        
        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 dirItems:
            name = item.fileName()
            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.fileName()),
                sizeStr,
                item.lastModified().toString("yyyy-MM-dd hh:mm"),
            )
            i = 1 - i
        
        content = dirListPage_html.format(
            Qt.escape(baseUrl),
            "".join(linkClasses.values()),
            self.trUtf8("Listing of {0}").format(basePath),
            parentStr,
            table
        )
        self.__content = QByteArray(content.encode("utf8"))
        self.__content.append(512 * b' ')
        
        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()