Helpviewer/AdBlock/AdBlockManager.py

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

# Copyright (c) 2009 - 2011 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing the AdBlock manager.
"""

import os

from PyQt4.QtCore import pyqtSignal, QObject, QUrl, QFile

from .AdBlockNetwork import AdBlockNetwork
from .AdBlockPage import AdBlockPage
from .AdBlockSubscription import AdBlockSubscription
from .AdBlockDialog import AdBlockDialog

from Utilities.AutoSaver import AutoSaver
import Utilities
import Preferences


class AdBlockManager(QObject):
    """
    Class implementing the AdBlock manager.
    
    @signal rulesChanged() emitted after some rule has changed
    """
    rulesChanged = pyqtSignal()
    
    def __init__(self, parent=None):
        """
        Constructor
        
        @param parent reference to the parent object (QObject)
        """
        QObject.__init__(self, parent)
        
        self.__loaded = False
        self.__subscriptionsLoaded = False
        self.__enabled = False
        self.__adBlockDialog = None
        self.__adBlockNetwork = None
        self.__adBlockPage = None
        self.__subscriptions = []
        self.__saveTimer = AutoSaver(self, self.save)
        
        self.rulesChanged.connect(self.__saveTimer.changeOccurred)
    
    def close(self):
        """
        Public method to close the open search engines manager.
        """
        self.__saveTimer.saveIfNeccessary()
    
    def isEnabled(self):
        """
        Public method to check, if blocking ads is enabled.
        
        @return flag indicating the enabled state (boolean)
        """
        if not self.__loaded:
            self.load()
        
        return self.__enabled
    
    def setEnabled(self, enabled):
        """
        Public slot to set the enabled state.
        
        @param enabled flag indicating the enabled state (boolean)
        """
        if self.isEnabled() == enabled:
            return
        
        self.__enabled = enabled
        if enabled:
            self.__loadSubscriptions()
        self.rulesChanged.emit()
    
    def network(self):
        """
        Public method to get a reference to the network block object.
        
        @return reference to the network block object (AdBlockNetwork)
        """
        if self.__adBlockNetwork is None:
            self.__adBlockNetwork = AdBlockNetwork(self)
        return self.__adBlockNetwork
    
    def page(self):
        """
        Public method to get a reference to the page block object.
        
        @return reference to the page block object (AdBlockPage)
        """
        if self.__adBlockPage is None:
            self.__adBlockPage = AdBlockPage(self)
        return self.__adBlockPage
    
    def __customSubscriptionLocation(self):
        """
        Private method to generate the path for custom subscriptions.
        
        @return URL for custom subscriptions (QUrl)
        """
        dataDir = os.path.join(Utilities.getConfigDir(), "browser", "subscriptions")
        if not os.path.exists(dataDir):
            os.makedirs(dataDir)
        fileName = os.path.join(dataDir, "adblock_subscription_custom")
        return QUrl.fromLocalFile(fileName)
    
    def __customSubscriptionUrl(self):
        """
        Private method to generate the URL for custom subscriptions.
        
        @return URL for custom subscriptions (QUrl)
        """
        location = self.__customSubscriptionLocation()
        encodedUrl = bytes(location.toEncoded()).decode()
        url = QUrl("abp:subscribe?location={0}&title={1}".format(
            encodedUrl, self.trUtf8("Custom Rules")))
        return url
    
    def customRules(self):
        """
        Public method to get a subscription for custom rules.
        
        @return subscription object for custom rules (AdBlockSubscription)
        """
        location = self.__customSubscriptionLocation()
        for subscription in self.__subscriptions:
            if subscription.location() == location:
                return subscription
        
        url = self.__customSubscriptionUrl()
        customAdBlockSubscription = AdBlockSubscription(url, self)
        self.addSubscription(customAdBlockSubscription)
        return customAdBlockSubscription
    
    def subscriptions(self):
        """
        Public method to get all subscriptions.
        
        @return list of subscriptions (list of AdBlockSubscription)
        """
        if not self.__loaded:
            self.load()
        
        return self.__subscriptions[:]
    
    def removeSubscription(self, subscription):
        """
        Public method to remove an AdBlock subscription.
        
        @param subscription AdBlock subscription to be removed (AdBlockSubscription)
        """
        if subscription is None:
            return
        
        try:
            self.__subscriptions.remove(subscription)
            rulesFileName = subscription.rulesFileName()
            QFile.remove(rulesFileName)
            self.rulesChanged.emit()
        except ValueError:
            pass
    
    def addSubscription(self, subscription):
        """
        Public method to add an AdBlock subscription.
        
        @param subscription AdBlock subscription to be added (AdBlockSubscription)
        """
        if subscription is None:
            return
        
        self.__subscriptions.append(subscription)
        
        subscription.rulesChanged.connect(self.rulesChanged)
        subscription.changed.connect(self.rulesChanged)
        
        self.rulesChanged.emit()
    
    def save(self):
        """
        Public method to save the AdBlock subscriptions.
        """
        if not self.__loaded:
            return
        
        Preferences.setHelp("AdBlockEnabled", self.__enabled)
        if self.__subscriptionsLoaded:
            subscriptions = []
            for subscription in self.__subscriptions:
                if subscription is None:
                    continue
                subscriptions.append(bytes(subscription.url().toEncoded()).decode())
                subscription.saveRules()
            Preferences.setHelp("AdBlockSubscriptions", subscriptions)
    
    def load(self):
        """
        Public method to load the AdBlock subscriptions.
        """
        if self.__loaded:
            return
        
        self.__loaded = True
        
        self.__enabled = Preferences.getHelp("AdBlockEnabled")
        if self.__enabled:
            self.__loadSubscriptions()
    
    def __loadSubscriptions(self):
        """
        Private method to load the set of subscriptions.
        """
        if self.__subscriptionsLoaded:
            return
        
        defaultSubscriptionUrl = \
            "abp:subscribe?location=http://adblockplus.mozdev.org/easylist/easylist.txt&title=EasyList"
        defaultSubscriptions = []
        defaultSubscriptions.append(
            bytes(self.__customSubscriptionUrl().toEncoded()).decode())
        defaultSubscriptions.append(defaultSubscriptionUrl)
        
        subscriptions = Preferences.getHelp("AdBlockSubscriptions")
        if len(subscriptions) == 0:
            subscriptions = defaultSubscriptions
        for subscription in subscriptions:
            url = QUrl.fromEncoded(subscription.encode())
            adBlockSubscription = AdBlockSubscription(url, self,
                subscription == defaultSubscriptionUrl)
            adBlockSubscription.rulesChanged.connect(self.rulesChanged)
            adBlockSubscription.changed.connect(self.rulesChanged)
            self.__subscriptions.append(adBlockSubscription)
        
        self.__subscriptionsLoaded = True
    
    def showDialog(self):
        """
        Public slot to show the AdBlock subscription management dialog.
        """
        if self.__adBlockDialog is None:
            self.__adBlockDialog = AdBlockDialog()
        
        self.__adBlockDialog.show()
        return self.__adBlockDialog