Helpviewer/WebPlugins/ClickToFlash/ClickToFlash.py

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

# Copyright (c) 2012 - 2013 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing the Flash blocker.
"""


from __future__ import unicode_literals    # __IGNORE_WARNING__

from PyQt4.QtCore import pyqtSlot, QUrl, Qt, QByteArray,  QTimer
from PyQt4.QtGui import QWidget, QMenu, QCursor, QDialog, QLabel, QFormLayout
from PyQt4.QtNetwork import QNetworkRequest
from PyQt4.QtWebKit import QWebHitTestResult, QWebElement, QWebView, \
    QWebElementCollection

from .Ui_ClickToFlash import Ui_ClickToFlash

import UI.PixmapCache


class ClickToFlash(QWidget, Ui_ClickToFlash):
    """
    Class implementing the Flash blocker.
    """
    _acceptedUrl = QUrl()
    _acceptedArgNames = []
    _acceptedArgValues = []

    def __init__(self, plugin, mimeType, url, argumentNames, argumentValues,
                 parent=None):
        """
        Constructor
        
        @param plugin reference to the plug-in (ClickToFlashPlugin)
        @param mimeType MIME type for the plug-in (string)
        @param url requested URL (QUrl)
        @param argumentNames list of argument names (list of strings)
        @param argumentValues list of argument values (list of strings)
        @param parent reference to the parent widget (QWidget)
        """
        super(ClickToFlash, self).__init__(parent)
        
        # Check AdBlock first
        import Helpviewer.HelpWindow
        manager = Helpviewer.HelpWindow.HelpWindow.adBlockManager()
        if manager.isEnabled():
            urlString = bytes(url.toEncoded()).decode()
            urlDomain = url.host()
            for subscription in manager.subscriptions():
                blockedRule = subscription.match(
                    QNetworkRequest(url), urlDomain, urlString)
                if blockedRule:
                    QTimer.singleShot(200, self.__hideAdBlocked)
                    return
        
        self.setupUi(self)
        
        self.__swapping = False
        self.__element = QWebElement()
        
        self.__plugin = plugin
        self.__url = QUrl(url)
        self.__argumentNames = argumentNames[:]
        self.__argumentValues = argumentValues[:]
        self.__mimeType = mimeType
        
        self.setContextMenuPolicy(Qt.CustomContextMenu)
        self.customContextMenuRequested.connect(self.__showContextMenu)
        self.setToolTip(self.__url.toString())
        
        iconName = plugin.getIconName(mimeType)
        if iconName:
            self.loadFlashButton.setIcon(UI.PixmapCache.getIcon(iconName))
        else:
            self.loadFlashButton.setText(self.trUtf8("Load"))
    
    @pyqtSlot()
    def on_loadFlashButton_clicked(self):
        """
        Private slot handling the flash activation.
        """
        self.__load()
    
    def __showContextMenu(self):
        """
        Private slot to show the context menu.
        """
        menu = QMenu()
        act = menu.addAction(self.trUtf8("Object blocked by ClickToFlash"))
        font = act.font()
        font.setBold(True)
        act.setFont(font)
        menu.addAction(
            self.trUtf8("Show information about object"), self.__showInfo)
        menu.addSeparator()
        menu.addAction(self.trUtf8("Load"), self.__load)
        menu.addAction(self.trUtf8("Delete object"), self.__hideAdBlocked)
        menu.addSeparator()
        host = self.__url.host()
        add = menu.addAction(
            self.trUtf8("Add '{0}' to Whitelist").format(host),
            self.__addToWhitelist)
        remove = menu.addAction(
            self.trUtf8("Remove '{0}' from Whitelist").format(host),
            self.__removeFromWhitelist)
        onWhitelist = self.__plugin.onWhitelist(host)
        add.setEnabled(not onWhitelist)
        remove.setEnabled(onWhitelist)
        menu.addSeparator()
        menu.addAction(self.trUtf8("Configure Whitelist"), self.__configure)
        menu.actions()[0].setEnabled(False)
        
        menu.exec_(QCursor.pos())
    
    def swapping(self):
        """
        Public method to check, if the plug-in is swapping.
        
        @return flag indicating the swapping status (boolean)
        """
        return self.__swapping
    
    def __configure(self):
        """
        Private slot to configure the whitelist.
        """
        self.__plugin.configure()
    
    def __addToWhitelist(self):
        """
        Private slot to add the host to the whitelist.
        """
        self.__plugin.addToWhitelist(self.__url.host())
    
    def __removeFromWhitelist(self):
        """
        Private slot to remove the host from the whitelist.
        """
        self.__plugin.removeFromWhitelist(self.__url.host())
    
    def __load(self, all=False):
        """
        Private slot to load the flash content.
        
        @param all flag indicating to load all flash players. (boolean)
        """
        self.__findElement()
        if not self.__element.isNull():
            substitute = self.__element.clone()
            substitute.setAttribute("type", self.__mimeType)
            self.__element.replace(substitute)

            ClickToFlash._acceptedUrl = self.__url
            ClickToFlash._acceptedArgNames = self.__argumentNames
            ClickToFlash._acceptedArgValues = self.__argumentValues
    
    def __findElement(self):
        """
        Private method to find the element belonging to this ClickToFlash
        instance.
        """
        parent = self.parentWidget()
        view = None
        while parent is not None:
            if isinstance(parent, QWebView):
                view = parent
                break
            parent = parent.parentWidget()
        if view is None:
            return
        
        objectPos = view.mapFromGlobal(self.loadFlashButton.mapToGlobal(
            self.loadFlashButton.pos()))
        objectFrame = view.page().frameAt(objectPos)
        hitResult = QWebHitTestResult()
        hitElement = QWebElement()
        
        if objectFrame is not None:
            hitResult = objectFrame.hitTestContent(objectPos)
            hitElement = hitResult.element()
        
        if not hitElement.isNull() and \
           hitElement.tagName().lower() in ["embed", "object"]:
            self.__element = hitElement
            return
        
        # hit test failed, trying to find element by src
        # attribute in elements of all frames on page (although less accurate
        frames = []
        frames.append(view.page().mainFrame())
        while frames:
            frame = frames.pop(0)
            if not frame:
                continue
            docElement = frame.documentElement()
            elements = QWebElementCollection()
            elements.append(docElement.findAll("embed"))
            elements.append(docElement.findAll("object"))
            
            for element in elements:
                if not self.__checkElement(element) and \
                   not self.__checkUrlOnElement(element, view):
                    continue
                self.__element = element
                return
            frames.extend(frame.childFrames())
    
    def __checkUrlOnElement(self, element, view):
        """
        Private slot to check the URL of an element.
        
        @param element reference to the element to check (QWebElement)
        @param view reference to the view object (QWebView)
        @return flag indicating a positive result (boolean)
        """
        checkString = element.attribute("src")
        if checkString == "":
            checkString = element.attribute("data")
        if checkString == "":
            checkString = element.attribute("value")
        
        checkString = view.url().resolved(QUrl(checkString)).toString(
            QUrl.RemoveQuery)
        return self.__url.toEncoded().contains(
            QByteArray(checkString.encode("utf-8")))
    
    def __checkElement(self, element):
        """
        Private slot to check an element against the saved arguments.
        
        @param element reference to the element to check (QWebElement)
        @return flag indicating a positive result (boolean)
        """
        if self.__argumentNames == element.attributeNames():
            for name in self.__argumentNames:
                if element.attribute(name) not in self.__argumentValues:
                    return False
            
            return True
        
        return False
    
    def __hideAdBlocked(self):
        """
        Private slot to hide the object.
        """
        self.__findElement()
        if not self.__element.isNull():
            self.__element.setStyleProperty("display", "none")
        else:
            self.hide()
    
    def __showInfo(self):
        """
        Private slot to show information about the blocked object.
        """
        dlg = QDialog()
        dlg.setWindowTitle(self.trUtf8("Flash Object"))
        dlg.setSizeGripEnabled(True)
        layout = QFormLayout(dlg)
        layout.addRow(QLabel(self.trUtf8("<b>Attribute Name</b>")),
                      QLabel(self.trUtf8("<b>Value</b>")))
        
        index = 0
        for name in self.__argumentNames:
            nameLabel = QLabel(self.__elide(name, length=30))
            value = self.__argumentValues[index]
            valueLabel = QLabel(self.__elide(value, length=60))
            valueLabel.setTextInteractionFlags(
                Qt.TextSelectableByMouse | Qt.LinksAccessibleByMouse)
            layout.addRow(nameLabel, valueLabel)
            
            index += 1
        
        if index == 0:
            layout.addRow(QLabel(self.trUtf8("No information available.")))
        
        dlg.setMaximumHeight(500)
        dlg.setMaximumWidth(500)
        dlg.exec_()
    
    def __elide(self, txt, mode=Qt.ElideMiddle, length=40):
        """
        Private method to elide some text.
        
        @param txt text to be elided (string)
        @keyparam mode elide mode (Qt.TextElideMode)
        @keyparam length amount of characters to be used (integer)
        @return the elided text (string)
        """
        if mode == Qt.ElideNone or len(txt) < length:
            return txt
        elif mode == Qt.ElideLeft:
            return "...{0}".format(txt[-length:])
        elif mode == Qt.ElideMiddle:
            return "{0}...{1}".format(txt[:length // 2], txt[-(length // 2):])
        elif mode == Qt.ElideRight:
            return "{0}...".format(txt[:length])
        else:
            # just in case
            return txt
    
    @classmethod
    def isAlreadyAccepted(cls, url, argumentNames, argumentValues):
        """
        Class method to check, if the given parameter combination is being
        accepted.
        
        @param url URL to be checked for (QUrl)
        @param argumentNames argument names to be checked for (list of strings)
        @param argumentValues argument values to be checked for (list of
            strings)
        @return flag indicating that this was already accepted (boolean)
        """
        return url == cls._acceptedUrl and \
               argumentNames == cls._acceptedArgNames and \
               argumentValues == cls._acceptedArgValues