Better error message and dialog box behaviour

qtgui/addclientprompt.py

@@ -47,6 +47,8 @@ class PromptWidget(QtWidgets.QDialog):
         self.comboBox = QtWidgets.QComboBox(self)
         self.comboBox.setEditable(True)
 
+        self.comboBox.currentTextChanged.connect(self.check) #not called when text is changed programatically
+
         if PromptWidget.wordlist:
             completer = QtWidgets.QCompleter(PromptWidget.wordlist)
             completer.setModelSorting(QtWidgets.QCompleter.CaseInsensitivelySortedModel)
@@ -65,22 +67,36 @@ class PromptWidget(QtWidgets.QDialog):
 
         layout.addWidget(self.comboBox)
 
-        errorString = QtCore.QCoreApplication.translate("PromptWidget", "Command not accepted!<br>Parameters, --switches and relative paths are not allowed.<br>Use nsm-proxy or write a starter-script instead.")
+        errorString = QtCore.QCoreApplication.translate("PromptWidget", "Command not found or not accepted!<br>Parameters, --switches and relative paths are not allowed.<br>Use nsm-proxy or write a starter-script instead.")
         errorString = "<i>" + errorString + "</i>"
         self.errorLabel = QtWidgets.QLabel(errorString)
         layout.addWidget(self.errorLabel)
-        self.errorLabel.hide() #shown in process
+        self.errorLabel.hide() #shown in process or check
 
-        buttonBox = QtWidgets.QDialogButtonBox(QtWidgets.QDialogButtonBox.Ok | QtWidgets.QDialogButtonBox.Cancel)
-        buttonBox.accepted.connect(self.process)
-        buttonBox.rejected.connect(self.reject)
-        layout.addWidget(buttonBox)
+        self.buttonBox = QtWidgets.QDialogButtonBox(QtWidgets.QDialogButtonBox.Ok | QtWidgets.QDialogButtonBox.Cancel)
+        self.buttonBox.accepted.connect(self.process)
+        self.buttonBox.rejected.connect(self.reject)
+        layout.addWidget(self.buttonBox)
 
         self.exec() #blocks until the dialog gets closed
 
     def abortHandler(self):
         pass
 
+
+    def check(self, currentText):
+        """Called every keypress.
+        We do preliminary error and collision checking here, so the engine does not have to throw
+        an error """
+        self.errorLabel.hide() #start in good faith
+        ok = self.buttonBox.button(QtWidgets.QDialogButtonBox.Ok)
+        if currentText in PromptWidget.wordlist: #this is taken literally. Any extra char or whitespace counts as false
+            ok.setEnabled(True)
+        else:
+            ok.setEnabled(False)
+            self.errorLabel.show()
+
+
     def process(self):
         """Careful! Calling this eats python errors without notice.
         Make sure your objects exists and your syntax is correct"""