Display error on unknown command

qutebrowser/app.py

@@ -13,6 +13,7 @@ def main():
     kp.set_cmd_text.connect(mw.status.cmd.set_cmd)
     mw.status.cmd.got_cmd.connect(cp.parse)
     mw.status.cmd.got_cmd.connect(mw.setFocus)
+    cp.error.connect(mw.status.disp_error)
     cmds.cmd_dict['open'].signal.connect(mw.tabs.openurl)
     cmds.cmd_dict['tabopen'].signal.connect(mw.tabs.tabopen)
     cmds.cmd_dict['quit'].signal.connect(QApplication.closeAllWindows) # FIXME

qutebrowser/commands.py

@@ -12,11 +12,17 @@ def register_all():
         cls.bind()
 
 class CommandParser(QObject):
+    error = pyqtSignal(str)
+
     def parse(self, text):
         parts = text.strip().split()
         cmd = parts[0]
         argv = parts[1:]
-        obj = cmd_dict[cmd]
+        try:
+            obj = cmd_dict[cmd]
+        except KeyError:
+            self.error.emit("{}: no such command".format(cmd))
+            return
         try:
             obj.check(argv)
         except TypeError:

qutebrowser/widgets/statusbar.py

@@ -6,7 +6,7 @@ class StatusBar(QWidget):
     def __init__(self, parent):
         super().__init__(parent)
         self.setObjectName(self.__class__.__name__)
-        self.bg_color("black")
+        self.bg_color("white", "black")
         self.hbox = QHBoxLayout(self)
         self.hbox.setObjectName("status_hbox")
         self.hbox.setContentsMargins(0, 0, 0, 0)
@@ -18,14 +18,18 @@ class StatusBar(QWidget):
         self.lbl = StatusText(self)
         self.hbox.addWidget(self.lbl)
 
-    def bg_color(self, color):
+    def bg_color(self, fg, bg):
         self.setStyleSheet("""
             * {
-                background: """ + color + """;
-                color: white;
+                background: """ + bg + """;
+                color: """ + fg + """;
                 font-family: Monospace;
             }""")
 
+    def disp_error(self, text):
+        self.bg_color('white', 'red')
+        self.lbl.setText('Error: {}'.format(text))
+
 class StatusText(QLabel):
     def __init__(self, parent):
         super().__init__(parent)