src/mastersettings.cpp

   1 /*
   2   Copyright (c) 2006 Paolo Capriotti <p.capriotti@gmail.com>
   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
  13 #include <QTextStream>
  14 #include <KDebug>
  15 #include <KStandardDirs>
  16
  17 #include "common.h"
  18 #include "foreach.h"
  19
  20
  21 QDomElement MasterSettings::node() const {
  22   if (m_node.isNull()) {
  23     QFile f(m_filename);
  24     if (!f.open(QFile::ReadOnly | QFile::Text) || !m_doc.setContent(&f)) {
  25       kWarning() << "Unable to open configuration file for reading.";
  26
  27 //       // create a stub configuration file
  28 //       {
  29 //         QFile stub(m_filename);
  30 //         if (!stub.open(QFile::WriteOnly | QFile::Text)) {
  31 //           kDebug() << "Unable to write to configuration file.";
  32 //           exit(1);
  33 //         }
  34 //         QTextStream stream(&stub);
  35 //         stream << "<?xml version=\"1.0\"?>\n"
  36 //                   "<configuration>\n"
  37 //                   "</configuration>\n";
  38 //       }
  39 //
  40 //       // reopen it
  41 //       if (!f.open(QFile::ReadOnly | QFile::Text))
  42 //         exit(1);
  43
  44       m_doc.appendChild(m_doc.createElement("configuration"));
  45 //      kDebug() << m_doc.toString();
  46     }
  47
  48
  49     const_cast<QDomElement&>(m_node) = m_doc.documentElement();
  50     Q_ASSERT(!m_node.isNull());
  51     Q_ASSERT(!m_node.ownerDocument().isNull());
  52   }
  53
  54   return m_node;
  55 }
  56
  57 MasterSettings::MasterSettings() {
  58   m_filename = KStandardDirs::locateLocal("config", "taguarc.xml");
  59 }
  60
  61 MasterSettings::MasterSettings(const QString& filename, LookupType lookup) {
  62   if (lookup == PathLookup)
  63     m_filename = filename;
  64   else
  65     m_filename = KStandardDirs::locateLocal("config", filename);
  66 }
  67
  68 MasterSettings::~MasterSettings() {
  69   sync();
  70 }
  71
  72 void MasterSettings::setupObserver(Observer& observer) {
  73   connect(observer.object, SIGNAL(destroyed(QObject*)), this, SLOT(objectDestroyed(QObject*)));
  74 }
  75
  76 void MasterSettings::onChange(QObject* obj, const char* method) {
  77   m_observers.push_front(Observer(obj, method, 0));
  78   setupObserver(m_observers.front());
  79 }
  80
  81 void MasterSettings::onChange(QObject* obj, const char* method, const char* dependency) {
  82   if (dependency) {
  83     // go backwards through all existing observers, searching for something
  84     // on which we depend.
  85     for (ObserverList::reverse_iterator it = m_observers.rbegin();
  86         it != m_observers.rend(); ++it) {
  87       const char* observer_class = it->object->metaObject()->className();
  88       if (observer_class && strcmp(observer_class, dependency) == 0) {
  89         // we hit a dependency wall: we can't be notified
  90         // before *it, so add the new Observer just here
  91         ObserverList::iterator us = m_observers.insert(it.base(), Observer(obj, method, dependency));
  92         setupObserver(*us);
  93
  94         // now check for a cyclic dependency
  95         const char* this_class = obj->metaObject()->className();
  96         for (ObserverList::iterator it2 = m_observers.begin(); it2 != us; ++it2) {
  97           if (it2->dependency && strcmp(it2->dependency, this_class) == 0) {
  98             // something which is notified before has us a dependency
  99             // this means that there is a cyclic dependency it2 -> us -> it.
 100             kWarning() << "Removing a cyclic dependency:" <<
 101               it2->object->metaObject()->className() << "->" <<
 102               this_class << "->" <<
 103               observer_class;
 104
 105             // remove the cycle
 106             it2->dependency = 0;
 107           }
 108         }
 109
 110         // done
 111         return;
 112       }
 113     }
 114   }
 115
 116   // no dependency
 117   onChange(obj, method);
 118 }
 119
 120 void MasterSettings::sync() {
 121   // store to file
 122   QFile f(m_filename);
 123   if (!f.open(QFile::WriteOnly | QFile::Text))
 124     kError() << "Cannot open configuration file for writing";
 125   else {
 126     QTextStream stream(&f);
 127     stream << node().ownerDocument().toString();
 128   }
 129
 130 }
 131
 132 void MasterSettings::objectDestroyed(QObject* obj) {
 133   for (ObserverList::iterator it = m_observers.begin();
 134        it != m_observers.end();) {
 135     if (it->object == obj) {
 136       it = m_observers.erase(it);
 137     }
 138     else {
 139       ++it;
 140     }
 141   }
 142 }
 143
 144 void MasterSettings::changed() {
 145   foreach (Observer& observer, m_observers) {
 146     observer.object->metaObject()->invokeMethod(observer.object, observer.method, Qt::DirectConnection);
 147   }
 148   sync();
 149 }
 150
 151 QString MasterSettings::filename() const {
 152   return m_filename;
 153 }
 154
 155 MasterSettings& settings() {
 156   static MasterSettings static_settings;
 157   return static_settings;
 158 }
 159
 160