Use a validator function for ConsoleLineEdit.

The prompts provided (e.g. sys.ps1/sys.ps2) could change during the lifetime of
the validator.

qutebrowser/widgets/console.py

@@ -43,7 +43,12 @@ class ConsoleLineEdit(CommandLineEdit):
             sys.ps1 = '>>> '
         if not hasattr(sys, 'ps2'):
             sys.ps2 = '... '
-        super().__init__(parent, prompts=[sys.ps1, sys.ps2])
+
+        def validator(text):
+            """Check if a given input is valid."""
+            return any(text.startswith(p) for p in (sys.ps1, sys.ps2))
+
+        super().__init__(parent, validator)
         self.setFont(config.get('fonts', 'debug-console'))
         self._more = False
         self._buffer = []

qutebrowser/widgets/misc.py

@@ -51,10 +51,15 @@ class CommandLineEdit(QLineEdit):
         _validator: The current command validator.
     """
 
-    def __init__(self, parent, prompts):
+    def __init__(self, parent, validator):
+        """Constructor.
+
+        Args:
+            validator: A function which checks if a given input is valid.
+        """
         super().__init__(parent)
         self.history = History()
-        self._validator = _CommandValidator(prompts, parent=self)
+        self._validator = _CommandValidator(validator, parent=self)
         self.setValidator(self._validator)
 
     def __repr__(self):
@@ -65,9 +70,9 @@ class _CommandValidator(QValidator):
 
     """Validator to prevent the : from getting deleted."""
 
-    def __init__(self, prompts, parent=None):
+    def __init__(self, validator, parent=None):
         super().__init__(parent)
-        self.prompts = prompts
+        self.validator = validator
 
     def validate(self, string, pos):
         """Override QValidator::validate.
@@ -79,7 +84,7 @@ class _CommandValidator(QValidator):
         Return:
             A tuple (status, string, pos) as a QValidator should.
         """
-        if any(string.startswith(c) for c in self.prompts):
+        if self.validator(string):
             return (QValidator.Acceptable, string, pos)
         else:
             return (QValidator.Invalid, string, pos)

qutebrowser/widgets/statusbar/command.py

@@ -77,7 +77,12 @@ class Command(MinimalLineEditMixin, CommandLineEdit):
     # for a possible fix.
 
     def __init__(self, parent=None):
-        CommandLineEdit.__init__(self, parent, STARTCHARS)
+
+        def validator(text):
+            """Check if a given input is valid."""
+            return any(text.startswith(p) for p in STARTCHARS)
+
+        CommandLineEdit.__init__(self, parent, validator)
         MinimalLineEditMixin.__init__(self)
         self.cursor_part = 0
         self.history.history = QApplication.instance().cmd_history.data