add a hot key (f4) for turning color on and off

subiquity/palette.py

@@ -73,8 +73,8 @@ STYLES = [
 
 
 STYLES_MONO = [
-    ('frame_header_fringe', 'black',   'white'),
-    ('frame_header',        'white',   'black'),
+    ('frame_header_fringe', 'white',   'black'),
+    ('frame_header',        'black',   'white'),
     ('body',                'white',   'black'),
 
     ('done_button',         'white',   'black'),
@@ -86,9 +86,12 @@ STYLES_MONO = [
 
     ('menu_button',         'white',   'black'),
     ('menu_button focus',   'black',   'white'),
+    ('frame_button',        'black',   'white'),
+    ('frame_button focus',  'white',   'black'),
 
     ('info_primary',        'white',   'black'),
     ('info_minor',          'white',   'black'),
+    ('info_minor header',   'black',   'white'),
     ('info_error',          'white',   'black'),
 
     ('string_input',        'white',   'black'),

subiquity/ui/views/help.py

@@ -112,10 +112,11 @@ GLOBAL_KEY_HELP = _("""\
 The following keys can be used at any time:""")
 
 GLOBAL_KEYS = (
-    (_('Control-Z, F2'), _('switch to shell')),
     (_("ESC"),           _('go back')),
-    (_('Control-L'),     _('redraw screen')),
     (_('F1'),            _('open help menu')),
+    (_('Control-Z, F2'), _('switch to shell')),
+    (_('Control-L, F3'), _('redraw screen')),
+    (_('Control-T, F4'), _('toggle color on and off')),
     )
 
 DRY_RUN_KEYS = (

subiquitycore/core.py

@@ -129,6 +129,8 @@ def setup_screen(colors, styles, is_linux_tty):
         _urwid_name_to_rgb = {}
         for i, n in enumerate(urwid_8_names):
             _urwid_name_to_rgb[n] = colors[i][1]
+        # Add an alias so things keep working with the mono palette.
+        _urwid_name_to_rgb['white'] = _urwid_name_to_rgb['light gray']
         return ISO_8613_3_Screen(_urwid_name_to_rgb), urwid_palette
 
 
@@ -463,9 +465,23 @@ class Application:
 
         self.loop.set_alarm_in(0.06, _run_script)
 
+    def toggle_color(self):
+        if self.is_color:
+            new_palette = self.STYLES_MONO
+            self.is_color = False
+        else:
+            new_palette = self.color_palette
+            self.is_color = True
+        self.loop.screen.register_palette(new_palette)
+        self.loop.screen.clear()
+
     def unhandled_input(self, key):
         if key == 'ctrl x':
             self.signal.emit_signal('control-x-quit')
+        elif key == 'f3':
+            self.loop.screen.clear()
+        elif key in ['ctrl t', 'f4']:
+            self.toggle_color()
 
     def load_controllers(self):
         log.debug("load_controllers")
@@ -510,13 +526,15 @@ class Application:
 
     def run(self):
         log.debug("Application.run")
+        screen, self.color_palette = setup_screen(
+            self.COLORS, self.STYLES, self.is_linux_tty)
         if (self.opts.run_on_serial and
                 os.ttyname(0) != "/dev/ttysclp0"):
+            self.is_color = False
             palette = self.STYLES_MONO
-            screen = urwid.raw_display.Screen()
         else:
-            screen, palette = setup_screen(
-                self.COLORS, self.STYLES, self.is_linux_tty)
+            self.is_color = True
+            palette = self.color_palette
 
         self.loop = urwid.MainLoop(
             self.ui, palette=palette, screen=screen,