Tray: Refresh icon if theme changed

If the icon theme changes, we should check if there is more suitable icon
name in the new theme.

src/tray.cpp

@@ -27,14 +27,14 @@ COPYRIGHT_HEADER*/
 #include <QMessageBox>
 #include <QApplication>
 #include <QPersistentModelIndex>
-#include <QDebug>
 
 #include <NetworkManagerQt/Manager>
 #include <NetworkManagerQt/WirelessDevice>
 
 #include "icons.h"
 #include "nmmodel.h"
 #include "nmproxy.h"
+#include "log.h"
 
 #include "nmlist.h"
 #include "connectioninfo.h"
@@ -49,6 +49,7 @@ class TrayPrivate
     void primaryConnectionUpdate();
     void setShown(QPersistentModelIndex const & index);
     void updateIcon();
+    void refreshIcon();
     void openCloseDialog(QDialog * dialog);
 
 public:
@@ -141,7 +142,13 @@ void TrayPrivate::updateIcon()
         return;
 
     mIconCurrent = mIcon2Show;
-    QStringList icon_names;
+    refreshIcon();
+}
+
+void TrayPrivate::refreshIcon()
+{
+    //Note: the icons::getIcon chooses the right icon from list of possible candidates
+    // -> we need to refresh the icon in case of icon theme change
     mTrayIcon.setIcon(icons::getIcon(mIconCurrent));
 }
 
@@ -186,6 +193,8 @@ Tray::Tray(QObject *parent/* = nullptr*/)
             , this, &Tray::onAboutTriggered);
     connect(d->mContextMenu.addAction(QIcon::fromTheme(QStringLiteral("application-exit")), Tray::tr("Quit")), &QAction::triggered
             , this, &Tray::onQuitTriggered);
+    //for listening on the QEvent::ThemeChange (is delivered only to QWidget objects)
+    d->mContextMenu.installEventFilter(this);
 
     d->mActEnableNetwork->setCheckable(true);
     d->mActEnableWifi->setCheckable(true);
@@ -241,6 +250,14 @@ Tray::~Tray()
 {
 }
 
+bool Tray::eventFilter(QObject * object, QEvent * event)
+{
+    Q_ASSERT(&d->mContextMenu == object);
+    if (QEvent::ThemeChange == event->type())
+        d->refreshIcon();
+    return false;
+}
+
 void Tray::onAboutTriggered()
 {
     QMessageBox::about(nullptr, Tray::tr("%1 about").arg(QStringLiteral("nm-tray"))

src/tray.h

@@ -36,6 +36,9 @@ Q_OBJECT
     Tray(QObject *parent = nullptr);
     ~Tray();
 
+protected:
+    virtual bool eventFilter(QObject * object, QEvent * event) override;
+
 private Q_SLOTS:
     //menu
     void onAboutTriggered();