New plugin detection for Symbian

Symbian can have very long running apps, which expect to pick up new
plugins without a restart. This change makes the plugin factory, which
is used for many internal plugin types, detect plugin changes and
update its list of plugins.

This uses the QNotifyChangeEvent class to watch for plugin directory
changes, including when they do not already exist, including on
removable drives with no media currently present. When a change is
detected, it triggers a rebuild of the plugin library paths, then
rescans for plugins only on the drive that changed.

An alternative implementation could have made use of watching software
installer P&S keys for notification of change. However these are not
triggered by memory card insertion or removal, so file system watchers
are used.

Task-number: QTBUG-20098
Reviewed-by: Shane Kearns

2 files changed, 164 insertions, 76 deletions

diff --git a/src/corelib/plugin/qfactoryloader.cpp b/src/corelib/plugin/qfactoryloader.cpp
index c8831e5..24b4be0 100644
--- a/src/corelib/plugin/qfactoryloader.cpp
+++ b/src/corelib/plugin/qfactoryloader.cpp
@@ -50,8 +50,13 @@
 #include "qmutex.h"
 #include "qplugin.h"
 #include "qpluginloader.h"
+#include "qlibraryinfo.h"
 #include "private/qobject_p.h"
 #include "private/qcoreapplication_p.h"
+#ifdef Q_OS_SYMBIAN
+#include "private/qcore_symbian_p.h"
+#include "private/qfilesystemwatcher_symbian_p.h"
+#endif
 
 QT_BEGIN_NAMESPACE
 
@@ -59,6 +64,23 @@ Q_GLOBAL_STATIC(QList<QFactoryLoader *>, qt_factory_loaders)
 
 Q_GLOBAL_STATIC_WITH_ARGS(QMutex, qt_factoryloader_mutex, (QMutex::Recursive))
 
+#ifdef Q_OS_SYMBIAN
+class QSymbianSystemPluginWatcher : public QSymbianFileSystemWatcherInterface
+{
+public:
+    QSymbianSystemPluginWatcher();
+    ~QSymbianSystemPluginWatcher();
+
+    void watchForUpdates();
+    void handlePathChanged(QNotifyChangeEvent *e);
+
+    QList<QNotifyChangeEvent*> watchers;
+    TDriveList drives;
+};
+
+Q_GLOBAL_STATIC(QSymbianSystemPluginWatcher, qt_symbian_system_plugin_watcher)
+#endif
+
 class QFactoryLoaderPrivate : public QObjectPrivate
 {
     Q_DECLARE_PUBLIC(QFactoryLoader)
@@ -98,102 +120,117 @@ QFactoryLoader::QFactoryLoader(const char *iid,
     QMutexLocker locker(qt_factoryloader_mutex());
     update();
     qt_factory_loaders()->append(this);
+#ifdef Q_OS_SYMBIAN
+    // kick off Symbian plugin watcher for updates
+    qt_symbian_system_plugin_watcher();
+#endif
 }
 
 
-
-void QFactoryLoader::update()
+void QFactoryLoader::updateDir(const QString &pluginDir, QSettings& settings)
 {
-#ifdef QT_SHARED
     Q_D(QFactoryLoader);
-    QStringList paths = QCoreApplication::libraryPaths();
-    QSettings settings(QSettings::UserScope, QLatin1String("Trolltech"));
-    for (int i = 0; i < paths.count(); ++i) {
-        const QString &pluginDir = paths.at(i);
-        // Already loaded, skip it...
-        if (d->loadedPaths.contains(pluginDir))
-            continue;
-        d->loadedPaths << pluginDir;
+    QString path = pluginDir + d->suffix;
+    if (!QDir(path).exists(QLatin1String(".")))
+        return;
 
-        QString path = pluginDir + d->suffix;
-        if (!QDir(path).exists(QLatin1String(".")))
-            continue;
+    QStringList plugins = QDir(path).entryList(QDir::Files);
+    QLibraryPrivate *library = 0;
+    for (int j = 0; j < plugins.count(); ++j) {
+        QString fileName = QDir::cleanPath(path + QLatin1Char('/') + plugins.at(j));
 
-        QStringList plugins = QDir(path).entryList(QDir::Files);
-        QLibraryPrivate *library = 0;
-        for (int j = 0; j < plugins.count(); ++j) {
-            QString fileName = QDir::cleanPath(path + QLatin1Char('/') + plugins.at(j));
+        if (qt_debug_component()) {
+            qDebug() << "QFactoryLoader::QFactoryLoader() looking at" << fileName;
+        }
+        library = QLibraryPrivate::findOrCreate(QFileInfo(fileName).canonicalFilePath());
+        if (!library->isPlugin(&settings)) {
             if (qt_debug_component()) {
-                qDebug() << "QFactoryLoader::QFactoryLoader() looking at" << fileName;
+                qDebug() << library->errorString;
+                qDebug() << "         not a plugin";
             }
-            library = QLibraryPrivate::findOrCreate(QFileInfo(fileName).canonicalFilePath());
-            if (!library->isPlugin(&settings)) {
+            library->release();
+            continue;
+        }
+        QString regkey = QString::fromLatin1("Qt Factory Cache %1.%2/%3:/%4")
+                         .arg((QT_VERSION & 0xff0000) >> 16)
+                         .arg((QT_VERSION & 0xff00) >> 8)
+                         .arg(QLatin1String(d->iid))
+                         .arg(fileName);
+        QStringList reg, keys;
+        reg = settings.value(regkey).toStringList();
+        if (reg.count() && library->lastModified == reg[0]) {
+            keys = reg;
+            keys.removeFirst();
+        } else {
+            if (!library->loadPlugin()) {
                 if (qt_debug_component()) {
                     qDebug() << library->errorString;
-                    qDebug() << "         not a plugin";
+                    qDebug() << "           could not load";
                 }
                 library->release();
                 continue;
             }
-            QString regkey = QString::fromLatin1("Qt Factory Cache %1.%2/%3:/%4")
-                             .arg((QT_VERSION & 0xff0000) >> 16)
-                             .arg((QT_VERSION & 0xff00) >> 8)
-                             .arg(QLatin1String(d->iid))
-                             .arg(fileName);
-            QStringList reg, keys;
-            reg = settings.value(regkey).toStringList();
-            if (reg.count() && library->lastModified == reg[0]) {
-                keys = reg;
-                keys.removeFirst();
-            } else {
-                if (!library->loadPlugin()) {
-                    if (qt_debug_component()) {
-                        qDebug() << library->errorString;
-                        qDebug() << "           could not load";
-                    }
-                    library->release();
-                    continue;
-                }
-                QObject *instance = library->instance();
-                if (!instance) {
-                    library->release();
-                    // ignore plugins that have a valid signature but cannot be loaded.
-                    continue;
-                }
-                QFactoryInterface *factory = qobject_cast<QFactoryInterface*>(instance);
-                if (instance && factory && instance->qt_metacast(d->iid))
-                    keys = factory->keys();
-                if (keys.isEmpty())
-                    library->unload();
-                reg.clear();
-                reg << library->lastModified;
-                reg += keys;
-                settings.setValue(regkey, reg);
-            }
-            if (qt_debug_component()) {
-                qDebug() << "keys" << keys;
-            }
-
-            if (keys.isEmpty()) {
+            QObject *instance = library->instance();
+            if (!instance) {
                 library->release();
+                // ignore plugins that have a valid signature but cannot be loaded.
                 continue;
             }
-            d->libraryList += library;
-            for (int k = 0; k < keys.count(); ++k) {
-                // first come first serve, unless the first
-                // library was built with a future Qt version,
-                // whereas the new one has a Qt version that fits
-                // better
-                QString key = keys.at(k);
-                if (!d->cs)
-                    key = key.toLower();
-                QLibraryPrivate *previous = d->keyMap.value(key);
-                if (!previous || (previous->qt_version > QT_VERSION && library->qt_version <= QT_VERSION)) {
-                    d->keyMap[key] = library;
-                    d->keyList += keys.at(k);
-                }
+            QFactoryInterface *factory = qobject_cast<QFactoryInterface*>(instance);
+            if (instance && factory && instance->qt_metacast(d->iid))
+                keys = factory->keys();
+            if (keys.isEmpty())
+                library->unload();
+            reg.clear();
+            reg << library->lastModified;
+            reg += keys;
+            settings.setValue(regkey, reg);
+        }
+        if (qt_debug_component()) {
+            qDebug() << "keys" << keys;
+        }
+
+        if (keys.isEmpty()) {
+            library->release();
+            continue;
+        }
+
+        int keysUsed = 0;
+        for (int k = 0; k < keys.count(); ++k) {
+            // first come first serve, unless the first
+            // library was built with a future Qt version,
+            // whereas the new one has a Qt version that fits
+            // better
+            QString key = keys.at(k);
+            if (!d->cs)
+                key = key.toLower();
+            QLibraryPrivate *previous = d->keyMap.value(key);
+            if (!previous || (previous->qt_version > QT_VERSION && library->qt_version <= QT_VERSION)) {
+                d->keyMap[key] = library;
+                d->keyList += keys.at(k);
+                keysUsed++;
             }
         }
+        if (keysUsed)
+            d->libraryList += library;
+        else
+            library->release();
+    }
+}
+
+void QFactoryLoader::update()
+{
+#ifdef QT_SHARED
+    Q_D(QFactoryLoader);
+    QStringList paths = QCoreApplication::libraryPaths();
+    QSettings settings(QSettings::UserScope, QLatin1String("Trolltech"));
+    for (int i = 0; i < paths.count(); ++i) {
+        const QString &pluginDir = paths.at(i);
+        // Already loaded, skip it...
+        if (d->loadedPaths.contains(pluginDir))
+            continue;
+        d->loadedPaths << pluginDir;
+        updateDir(pluginDir, settings);
     }
 #else
     Q_D(QFactoryLoader);
@@ -264,6 +301,56 @@ void QFactoryLoader::refreshAll()
     }
 }
 
+#ifdef Q_OS_SYMBIAN
+QSymbianSystemPluginWatcher::QSymbianSystemPluginWatcher()
+{
+    qt_s60GetRFs().DriveList(drives);
+    watchForUpdates();
+}
+
+QSymbianSystemPluginWatcher::~QSymbianSystemPluginWatcher()
+{
+    qDeleteAll(watchers);
+}
+
+void QSymbianSystemPluginWatcher::watchForUpdates()
+{
+    QString installPathPlugins =  QLibraryInfo::location(QLibraryInfo::PluginsPath);
+    if (installPathPlugins.at(1) == QChar(QLatin1Char(':')))
+        return;
+
+    installPathPlugins.prepend(QLatin1String("?:"));
+    installPathPlugins = QDir::toNativeSeparators(installPathPlugins);
+    RFs& fs = qt_s60GetRFs();
+    for (int i=0; i<KMaxDrives; i++) {
+        int attr = drives[i];
+        if ((attr & KDriveAttLocal) && !(attr & KDriveAttRom)) {
+            // start new watcher
+            TChar driveLetter;
+            fs.DriveToChar(i, driveLetter);
+            installPathPlugins[0] = driveLetter;
+            TPtrC ptr(qt_QString2TPtrC(installPathPlugins));
+            QNotifyChangeEvent *event = q_check_ptr(new QNotifyChangeEvent(fs, ptr, this, true));
+            watchers.push_back(event);
+        }
+    }
+}
+
+void QSymbianSystemPluginWatcher::handlePathChanged(QNotifyChangeEvent *e)
+{
+    QCoreApplicationPrivate::rebuildInstallLibraryPaths();
+    QMutexLocker locker(qt_factoryloader_mutex());
+    QString dirName(QDir::cleanPath(qt_TDesC2QString(e->watchedPath)));
+    QList<QFactoryLoader *> *loaders = qt_factory_loaders();
+    for (QList<QFactoryLoader *>::const_iterator it = loaders->constBegin();
+         it != loaders->constEnd(); ++it) {
+        QSettings settings(QSettings::UserScope, QLatin1String("Trolltech"));
+        (*it)->updateDir(dirName, settings);
+    }
+}
+
+#endif
+
 QT_END_NAMESPACE
 
 #endif // QT_NO_LIBRARY
diff --git a/src/corelib/plugin/qfactoryloader_p.h b/src/corelib/plugin/qfactoryloader_p.h
index e90ebf6..8548ab2 100644
--- a/src/corelib/plugin/qfactoryloader_p.h
+++ b/src/corelib/plugin/qfactoryloader_p.h
@@ -82,6 +82,7 @@ public:
 #endif
 
     void update();
+    void updateDir(const QString &pluginDir, QSettings& settings);
 
     static void refreshAll();
 };