fix: compiler warnings

Mostly QFutureWatcher leaks, fixed by using QFuture.then
Also calculator false positive leak

Author: soramanew

plugin/src/Caelestia/Internal/cachingimagemanager.cpp

@@ -105,34 +105,26 @@ void CachingImageManager::updateSource(const QString& path) {
 
     m_shaPath = path;
 
-    const auto future = QtConcurrent::run(&CachingImageManager::sha256sum, path);
-
-    const auto watcher = new QFutureWatcher<QString>(this);
-
-    connect(watcher, &QFutureWatcher<QString>::finished, this, [watcher, path, this]() {
+    QtConcurrent::run(&CachingImageManager::sha256sum, path).then(this, [path, this](const QString& sha) {
         if (m_path != path) {
-            // Object is destroyed or path has changed, ignore
-            watcher->deleteLater();
             return;
         }
 
         const QSize size = effectiveSize();
 
         if (!m_item || !size.width() || !size.height()) {
-            watcher->deleteLater();
             return;
         }
 
         const QString fillMode = m_item->property("fillMode").toString();
         // clang-format off
         const QString filename = QString("%1@%2x%3-%4.png")
-            .arg(watcher->result()).arg(size.width()).arg(size.height())
+            .arg(sha).arg(size.width()).arg(size.height())
             .arg(fillMode == "PreserveAspectCrop" ? "crop" : fillMode == "PreserveAspectFit" ? "fit" : "stretch");
         // clang-format on
 
         const QUrl cache = m_cacheDir.resolved(QUrl(filename));
         if (m_cachePath == cache) {
-            watcher->deleteLater();
             return;
         }
 
@@ -141,7 +133,6 @@ void CachingImageManager::updateSource(const QString& path) {
 
         if (!cache.isLocalFile()) {
             qWarning() << "CachingImageManager::updateSource: cachePath" << cache << "is not a local file";
-            watcher->deleteLater();
             return;
         }
 
@@ -157,11 +148,7 @@ void CachingImageManager::updateSource(const QString& path) {
         if (m_shaPath == path) {
             m_shaPath = QString();
         }
-
-        watcher->deleteLater();
     });
-
-    watcher->setFuture(future);
 }
 
 QUrl CachingImageManager::cachePath() const {

plugin/src/Caelestia/Models/filesystemmodel.cpp

@@ -219,7 +219,7 @@ void FileSystemModel::watchDirIfRecursive(const QString& path) {
     if (m_recursive && m_watchChanges) {
         const auto currentDir = m_dir;
         const bool showHidden = m_showHidden;
-        const auto future = QtConcurrent::run([showHidden, path]() {
+        auto future = QtConcurrent::run([showHidden, path]() {
             QDir::Filters filters = QDir::Dirs | QDir::NoDotAndDotDot;
             if (showHidden) {
                 filters |= QDir::Hidden;
@@ -232,16 +232,12 @@ void FileSystemModel::watchDirIfRecursive(const QString& path) {
             }
             return dirs;
         });
-        const auto watcher = new QFutureWatcher<QStringList>(this);
-        connect(watcher, &QFutureWatcher<QStringList>::finished, this, [currentDir, showHidden, watcher, this]() {
-            const auto paths = watcher->result();
+        future.then(this, [currentDir, showHidden, this](const QStringList& paths) {
             if (currentDir == m_dir && showHidden == m_showHidden && !paths.isEmpty()) {
                 // Ignore if dir or showHidden has changed
                 m_watcher.addPaths(paths);
             }
-            watcher->deleteLater();
         });
-        watcher->setFuture(future);
     }
 }
 
@@ -295,7 +291,7 @@ void FileSystemModel::updateEntriesForDir(const QString& dir) {
         oldPaths << entry->path();
     }
 
-    const auto future = QtConcurrent::run([=](QPromise<QPair<QSet<QString>, QSet<QString>>>& promise) {
+    auto future = QtConcurrent::run([=](QPromise<QPair<QSet<QString>, QSet<QString>>>& promise) {
         const auto flags = recursive ? QDirIterator::Subdirectories : QDirIterator::NoIteratorFlags;
 
         std::optional<QDirIterator> iter;
@@ -353,7 +349,7 @@ void FileSystemModel::updateEntriesForDir(const QString& dir) {
             newPaths.insert(path);
         }
 
-        if (promise.isCanceled() || newPaths == oldPaths) {
+        if (promise.isCanceled()) {
             return;
         }
 
@@ -365,23 +361,17 @@ void FileSystemModel::updateEntriesForDir(const QString& dir) {
     }
     m_futures.insert(dir, future);
 
-    const auto watcher = new QFutureWatcher<QPair<QSet<QString>, QSet<QString>>>(this);
-
-    connect(watcher, &QFutureWatcher<QPair<QSet<QString>, QSet<QString>>>::finished, this, [dir, watcher, this]() {
-        m_futures.remove(dir);
-
-        if (!watcher->future().isResultReadyAt(0)) {
-            watcher->deleteLater();
-            return;
-        }
-
-        const auto result = watcher->result();
-        applyChanges(result.first, result.second);
-
-        watcher->deleteLater();
-    });
-
-    watcher->setFuture(future);
+    future
+        .then(this,
+            [dir, this](QPair<QSet<QString>, QSet<QString>> result) {
+                m_futures.remove(dir);
+                if (!result.first.isEmpty() || !result.second.isEmpty()) {
+                    applyChanges(result.first, result.second);
+                }
+            })
+        .onCanceled(this, [dir, this]() {
+            m_futures.remove(dir);
+        });
 }
 
 void FileSystemModel::applyChanges(const QSet<QString>& removedPaths, const QSet<QString>& addedPaths) {

plugin/src/Caelestia/Services/audiocollector.cpp

@@ -221,7 +221,7 @@ AudioCollector::AudioCollector(QObject* parent)
     , m_writeBuffer(&m_buffer2) {}
 
 AudioCollector::~AudioCollector() {
-    stop();
+    AudioCollector::stop();
 }
 
 void AudioCollector::start() {

plugin/src/Caelestia/appdb.cpp

@@ -11,7 +11,7 @@ AppEntry::AppEntry(QObject* entry, unsigned int frequency, QObject* parent)
     , m_entry(entry)
     , m_frequency(frequency) {
     const auto mo = m_entry->metaObject();
-    const auto tmo = metaObject();
+    const auto tmo = &AppEntry::staticMetaObject;
 
     for (const auto& prop :
         { "name", "comment", "execString", "startupClass", "genericName", "categories", "keywords" }) {

plugin/src/Caelestia/qalculator.cpp

@@ -1,7 +1,6 @@
 #include "qalculator.hpp"
 
 #include <libqalculate/qalculate.h>
-#include <qfuturewatcher.h>
 #include <qtconcurrentrun.h>
 
 namespace caelestia {
@@ -11,7 +10,10 @@ QMutex Qalculator::s_calculatorMutex;
 Qalculator::Qalculator(QObject* parent)
     : QObject(parent) {
     if (!CALCULATOR) {
-        new Calculator();
+        // Calculator constructor sets the global `calculator` pointer (CALCULATOR macro),
+        // but we need to assign it to a var so compiler doesn't flag it as a leak
+        static const auto* const instance = new Calculator();
+        Q_UNUSED(instance)
         CALCULATOR->loadExchangeRates();
         CALCULATOR->loadGlobalDefinitions();
         CALCULATOR->loadLocalDefinitions();
@@ -79,7 +81,7 @@ void Qalculator::evalAsync(const QString& expr) {
         emit busyChanged();
     }
 
-    const auto future = QtConcurrent::run([expr]() -> QPair<QString, QString> {
+    QtConcurrent::run([expr]() -> QPair<QString, QString> {
         QMutexLocker locker(&s_calculatorMutex);
 
         EvaluationOptions eo;
@@ -109,18 +111,12 @@ void Qalculator::evalAsync(const QString& expr) {
 
         const QString rawStr = QString::fromStdString(result);
         return { QString("%1 = %2").arg(parsed).arg(result), rawStr };
-    });
-
-    auto* watcher = new QFutureWatcher<QPair<QString, QString>>(this);
-
-    connect(watcher, &QFutureWatcher<QPair<QString, QString>>::finished, this, [this, watcher, gen]() {
-        watcher->deleteLater();
-
+    }).then(this, [this, gen](QPair<QString, QString> result) {
         if (gen != m_generation) {
             return;
         }
 
-        const auto [formatted, raw] = watcher->result();
+        const auto& [formatted, raw] = result;
 
         if (m_result != formatted) {
             m_result = formatted;
@@ -135,8 +131,6 @@ void Qalculator::evalAsync(const QString& expr) {
             emit busyChanged();
         }
     });
-
-    watcher->setFuture(future);
 }
 
 QString Qalculator::result() const {