Make SearchManager singleton

src/base/search/searchpluginmanager.cpp

@@ -35,6 +35,7 @@
 #include <QDomElement>
 #include <QDomNode>
 #include <QList>
+#include <QPointer>
 #include <QProcess>
 
 #include "base/logger.h"
@@ -47,11 +48,16 @@
 #include "searchdownloadhandler.h"
 #include "searchhandler.h"
 
-static inline void removePythonScriptIfExists(const QString &scriptPath)
+namespace
+{
+    inline void removePythonScriptIfExists(const QString &scriptPath)
     {
         Utils::Fs::forceRemove(scriptPath);
         Utils::Fs::forceRemove(scriptPath + "c");
     }
+}
+
+QPointer<SearchPluginManager> SearchPluginManager::m_instance = nullptr;
 
 const QHash<QString, QString> SearchPluginManager::m_categoryNames {
     {"all", QT_TRANSLATE_NOOP("SearchEngine", "All categories")},
@@ -68,6 +74,9 @@ const QHash<QString, QString> SearchPluginManager::m_categoryNames {
 SearchPluginManager::SearchPluginManager()
     : m_updateUrl(QString("http://searchplugins.qbittorrent.org/%1/engines/").arg(Utils::Misc::pythonVersion() >= 3 ? "nova3" : "nova"))
 {
+    Q_ASSERT(!m_instance); // only one instance is allowed
+    m_instance = this;
+
     updateNova();
     update();
 }
@@ -77,6 +86,11 @@ SearchPluginManager::~SearchPluginManager()
     qDeleteAll(m_plugins);
 }
 
+SearchPluginManager *SearchPluginManager::instance()
+{
+    return m_instance;
+}
+
 QStringList SearchPluginManager::allPlugins() const
 {
     return m_plugins.keys();

src/base/search/searchpluginmanager.h

@@ -61,6 +61,8 @@ public:
     SearchPluginManager();
     ~SearchPluginManager() override;
 
+    static SearchPluginManager *instance();
+
     QStringList allPlugins() const;
     QStringList enabledPlugins() const;
     QStringList supportedCategories() const;
@@ -107,6 +109,7 @@ private:
 
     static QString pluginPath(const QString &name);
 
+    static QPointer<SearchPluginManager> m_instance;
     static const QHash<QString, QString> m_categoryNames;
 
     const QString m_updateUrl;

src/gui/search/searchwidget.cpp

@@ -135,17 +135,18 @@ SearchWidget::SearchWidget(MainWindow *mainWindow)
     connect(m_tabStatusChangedMapper, static_cast<void (QSignalMapper::*)(QWidget *)>(&QSignalMapper::mapped)
             , this, &SearchWidget::tabStatusChanged);
 
-    m_searchManager = new SearchPluginManager;
+    // NOTE: Although SearchManager is Application-wide component now, we still create it the legacy way.
+    auto *searchManager = new SearchPluginManager;
     const auto onPluginChanged = [this]()
     {
         fillCatCombobox();
         fillPluginComboBox();
         selectActivePage();
     };
-    connect(m_searchManager, &SearchPluginManager::pluginInstalled, this, onPluginChanged);
-    connect(m_searchManager, &SearchPluginManager::pluginUninstalled, this, onPluginChanged);
-    connect(m_searchManager, &SearchPluginManager::pluginUpdated, this, onPluginChanged);
-    connect(m_searchManager, &SearchPluginManager::pluginEnabled, this, onPluginChanged);
+    connect(searchManager, &SearchPluginManager::pluginInstalled, this, onPluginChanged);
+    connect(searchManager, &SearchPluginManager::pluginUninstalled, this, onPluginChanged);
+    connect(searchManager, &SearchPluginManager::pluginUpdated, this, onPluginChanged);
+    connect(searchManager, &SearchPluginManager::pluginEnabled, this, onPluginChanged);
 
     // Fill in category combobox
     onPluginChanged();
@@ -163,7 +164,7 @@ void SearchWidget::fillCatCombobox()
 
     using QStrPair = QPair<QString, QString>;
     QList<QStrPair> tmpList;
-    foreach (const QString &cat, m_searchManager->supportedCategories())
+    foreach (const QString &cat, SearchPluginManager::instance()->supportedCategories())
         tmpList << qMakePair(SearchPluginManager::categoryFullName(cat), cat);
     std::sort(tmpList.begin(), tmpList.end(), [](const QStrPair &l, const QStrPair &r) { return (QString::localeAwareCompare(l.first, r.first) < 0); });
 
@@ -185,8 +186,8 @@ void SearchWidget::fillPluginComboBox()
 
     using QStrPair = QPair<QString, QString>;
     QList<QStrPair> tmpList;
-    foreach (const QString &name, m_searchManager->enabledPlugins())
-        tmpList << qMakePair(m_searchManager->pluginFullName(name), name);
+    foreach (const QString &name, SearchPluginManager::instance()->enabledPlugins())
+        tmpList << qMakePair(SearchPluginManager::instance()->pluginFullName(name), name);
     std::sort(tmpList.begin(), tmpList.end(), [](const QStrPair &l, const QStrPair &r) { return (l.first < r.first); } );
 
     foreach (const QStrPair &p, tmpList)
@@ -208,7 +209,7 @@ QString SearchWidget::selectedPlugin() const
 
 void SearchWidget::selectActivePage()
 {
-    if (m_searchManager->allPlugins().isEmpty()) {
+    if (SearchPluginManager::instance()->allPlugins().isEmpty()) {
         m_ui->stackedPages->setCurrentWidget(m_ui->emptyPage);
         m_ui->m_searchPattern->setEnabled(false);
         m_ui->comboCategory->setEnabled(false);
@@ -227,7 +228,7 @@ void SearchWidget::selectActivePage()
 SearchWidget::~SearchWidget()
 {
     qDebug("Search destruction");
-    delete m_searchManager;
+    delete SearchPluginManager::instance();
     delete m_ui;
 }
 
@@ -262,7 +263,7 @@ void SearchWidget::selectMultipleBox(int index)
 
 void SearchWidget::on_pluginsButton_clicked()
 {
-    new PluginSelectDlg(m_searchManager, this);
+    new PluginSelectDlg(SearchPluginManager::instance(), this);
 }
 
 void SearchWidget::searchTextEdited(QString)
@@ -303,15 +304,15 @@ void SearchWidget::on_searchButton_clicked()
     }
 
     QStringList plugins;
-    if (selectedPlugin() == "all") plugins = m_searchManager->allPlugins();
-    else if (selectedPlugin() == "enabled") plugins = m_searchManager->enabledPlugins();
-    else if (selectedPlugin() == "multi") plugins = m_searchManager->enabledPlugins();
+    if (selectedPlugin() == "all") plugins = SearchPluginManager::instance()->allPlugins();
+    else if (selectedPlugin() == "enabled") plugins = SearchPluginManager::instance()->enabledPlugins();
+    else if (selectedPlugin() == "multi") plugins = SearchPluginManager::instance()->enabledPlugins();
     else plugins << selectedPlugin();
 
     qDebug("Search with category: %s", qUtf8Printable(selectedCategory()));
 
     // Launch search
-    auto *searchHandler = m_searchManager->startSearch(pattern, selectedCategory(), plugins);
+    auto *searchHandler = SearchPluginManager::instance()->startSearch(pattern, selectedCategory(), plugins);
 
     // Tab Addition
     auto *newTab = new SearchTab(searchHandler, this);

src/gui/search/searchwidget.h

@@ -37,7 +37,6 @@ class QSignalMapper;
 class QTabWidget;
 
 class MainWindow;
-class SearchPluginManager;
 class SearchTab;
 
 namespace Ui
@@ -80,7 +79,6 @@ private:
     QString selectedPlugin() const;
 
     Ui::SearchWidget *m_ui;
-    SearchPluginManager *m_searchManager;
     QSignalMapper *m_tabStatusChangedMapper;
     QPointer<SearchTab> m_currentSearchTab; // Selected tab
     QPointer<SearchTab> m_activeSearchTab; // Tab with running search