gui: more greeter interactions

+ double click item to open node
+ Enter key while recent nodes are focused opens selected

Change-Id: I397f743faec70e623b5ef9a86d61625f8db7e933
Reviewed-on: https://forge.frm2.tum.de/review/c/secop/frappy/+/30736
Tested-by: Jenkins Automated Tests <pedersen+jenkins@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>
Reviewed-by: Alexander Zaft <a.zaft@fz-juelich.de>

frappy/gui/mainwindow.py

@@ -22,7 +22,7 @@
 # *****************************************************************************
 
 from frappy.gui.qt import QAction, QInputDialog, QKeySequence, QMainWindow, \
-    QMessageBox, QPixmap, QSettings, QShortcut, QWidget, pyqtSignal, \
+    QMessageBox, QPixmap, QSettings, QShortcut, Qt, QWidget, pyqtSignal, \
     pyqtSlot
 
 import frappy.version
@@ -44,6 +44,10 @@ class Greeter(QWidget):
             # maybe change it at runtime instead of second file?
             self.logoLabel.setPixmap(QPixmap(':/icons/logo_subtitle_light'))
         self.loadRecent()
+        self.recentNodes.itemDoubleClicked.connect(self.recentNodeDoubleClicked)
+        self.shortcut = QShortcut(QKeySequence("Return"), self.recentNodes,
+                                  self.on_connectRecentButton_clicked,
+                                  context=Qt.ShortcutContext.WidgetWithChildrenShortcut)
 
     def loadRecent(self):
         self.recentNodes.clear()
@@ -67,6 +71,9 @@ class Greeter(QWidget):
         self.addnodes.emit([self.secnodeEdit.text()
                             or self.secnodeEdit.placeholderText()])
 
+    def recentNodeDoubleClicked(self, item):
+        self.addnodes.emit([item.text()])
+
 
 class MainWindow(QMainWindow):
     recentNodesChanged = pyqtSignal()