src/mastersettings.cpp

   1 /*
   2   Copyright (c) 2006 Paolo Capriotti <p.capriotti@sns.it>
   3             (c) 2006 Maurizio Monge <maurizio.monge@kdemail.net>
   4
   5   This program is free software; you can redistribute it and/or modify
   6   it under the terms of the GNU General Public License as published by
   7   the Free Software Foundation; either version 2 of the License, or
   8   (at your option) any later version.
   9 */
  10
  11 #include "mastersettings.h"
  12 #include "common.h"
  13 #include <QTextStream>
  14
  15 QDomElement MasterSettings::node() const {
  16   if (m_node.isNull()) {
  17     QFile f(m_filename);
  18     if (!f.open(QFile::ReadOnly | QFile::Text) || !m_doc.setContent(&f)) {
  19       ERROR("Unable to open configuration file for reading.");
  20
  21 //       // create a stub configuration file
  22 //       {
  23 //         QFile stub(m_filename);
  24 //         if (!stub.open(QFile::WriteOnly | QFile::Text)) {
  25 //           std::cout << "Unable to write to configuration file." << std::endl;
  26 //           exit(1);
  27 //         }
  28 //         QTextStream stream(&stub);
  29 //         stream << "<?xml version=\"1.0\"?>\n"
  30 //                   "<configuration>\n"
  31 //                   "</configuration>\n";
  32 //       }
  33 //
  34 //       // reopen it
  35 //       if (!f.open(QFile::ReadOnly | QFile::Text))
  36 //         exit(1);
  37
  38       m_doc.appendChild(m_doc.createElement("configuration"));
  39 //      std::cout << m_doc.toString() << std::endl;
  40     }
  41
  42
  43     const_cast<QDomElement&>(m_node) = m_doc.documentElement();
  44     Q_ASSERT(!m_node.isNull());
  45     Q_ASSERT(!m_node.ownerDocument().isNull());
  46   }
  47
  48   return m_node;
  49 }
  50
  51 MasterSettings::MasterSettings(const QString& filename)
  52 : m_filename(QDir(QDir::homePath()).filePath(filename)) { }
  53
  54 MasterSettings::~MasterSettings() {
  55   sync();
  56 }
  57
  58 void MasterSettings::setupObserver(Observer& observer) {
  59   connect(observer.object, SIGNAL(destroyed(QObject*)), this, SLOT(objectDestroyed(QObject*)));
  60 }
  61
  62 void MasterSettings::onChange(QObject* obj, const char* method) {
  63   m_observers.push_front(Observer(obj, method, 0));
  64   setupObserver(m_observers.front());
  65 }
  66
  67 void MasterSettings::onChange(QObject* obj, const char* method, const char* dependency) {
  68   if (dependency) {
  69     // go backwards through all existing observers, searching for something
  70     // on which we depend.
  71     for (ObserverList::reverse_iterator it = m_observers.rbegin();
  72         it != m_observers.rend(); ++it) {
  73       const char* observer_class = it->object->metaObject()->className();
  74       if (observer_class && strcmp(observer_class, dependency) == 0) {
  75         // we hit a dependency wall: we can't be notified
  76         // before *it, so add the new Observer just here
  77         ObserverList::iterator us = m_observers.insert(it.base(), Observer(obj, method, dependency));
  78         setupObserver(*us);
  79
  80         // now check for a cyclic dependency
  81         const char* this_class = obj->metaObject()->className();
  82         for (ObserverList::iterator it2 = m_observers.begin(); it2 != us; ++it2) {
  83           if (it2->dependency && strcmp(it2->dependency, this_class) == 0) {
  84             // something which is notified before has us a dependency
  85             // this means that there is a cyclic dependency it2 -> us -> it.
  86             WARNING("Removing a cyclic dependency: " <<
  87               it2->object->metaObject()->className() << " -> " <<
  88               this_class << " -> " <<
  89               observer_class);
  90
  91             // remove the cycle
  92             it2->dependency = 0;
  93           }
  94         }
  95
  96         // done
  97         return;
  98       }
  99     }
 100   }
 101
 102   // no dependency
 103   onChange(obj, method);
 104 }
 105
 106 void MasterSettings::sync() {
 107   // store to file
 108   QFile f(m_filename);
 109   if (!f.open(QFile::WriteOnly | QFile::Text))
 110     ERROR("Cannot open configuration file for writing");
 111   else {
 112     QTextStream stream(&f);
 113     stream << node().ownerDocument().toString();
 114   }
 115
 116 }
 117
 118 void MasterSettings::objectDestroyed(QObject* obj) {
 119   for (ObserverList::iterator it = m_observers.begin();
 120        it != m_observers.end();) {
 121     if (it->object == obj) {
 122       it = m_observers.erase(it);
 123     }
 124     else {
 125       ++it;
 126     }
 127   }
 128 }
 129
 130 void MasterSettings::changed() {
 131   foreach (Observer& observer, m_observers) {
 132     observer.object->metaObject()->invokeMethod(observer.object, observer.method, Qt::DirectConnection);
 133   }
 134   sync();
 135 }
 136
 137 MasterSettings& settings() {
 138   static MasterSettings static_settings(".taguarc.xml");
 139   return static_settings;
 140 }
 141
 142