Respect DE icon for app.

src/librssguard/gui/dialogs/formmain.cpp

@@ -58,6 +58,7 @@ FormMain::FormMain(QWidget* parent, Qt::WindowFlags f)
   m_ui->setupUi(this);
   qApp->setMainForm(this);
 
+  setWindowIcon(qApp->desktopAwareIcon());
   setWindowTitle(APP_LONG_NAME);
 
 #if defined (USE_WEBENGINE)

src/librssguard/miscellaneous/application.cpp

@@ -426,6 +426,17 @@ NetworkUrlInterceptor* Application::urlIinterceptor() {
 
 #endif
 
+QIcon Application::desktopAwareIcon() const {
+  auto from_theme = m_icons->fromTheme(APP_LOW_NAME);
+
+  if (!from_theme.isNull()) {
+    return from_theme;
+  }
+  else {
+    return QIcon(APP_ICON_PATH);
+  }
+}
+
 void Application::showTrayIcon() {
   // Display tray icon if it is enabled and available.
   if (SystemTrayIcon::isSystemTrayActivated()) {

src/librssguard/miscellaneous/application.h

@@ -85,6 +85,8 @@ class RSSGUARD_DLLSPEC Application : public QtSingleApplication {
     NetworkUrlInterceptor* urlIinterceptor();
 #endif
 
+    QIcon desktopAwareIcon() const;
+
     QString tempFolder() const;
     QString documentsFolder() const;
     QString homeFolder() const;

src/rssguard/main.cpp

@@ -69,7 +69,7 @@ int main(int argc, char* argv[]) {
   Application::setApplicationName(APP_NAME);
   Application::setApplicationVersion(APP_VERSION);
   Application::setOrganizationDomain(APP_URL);
-  Application::setWindowIcon(QIcon(APP_ICON_PATH));
+  Application::setWindowIcon(qApp->desktopAwareIcon());
 
   qApp->reactOnForeignNotifications();