only allow downgrading color/ascii experience on serial

and collapse ascii/color choice to a single 'rich' toggle

subiquity/ui/views/help.py

@@ -178,7 +178,10 @@ GLOBAL_KEYS = (
     (_('F1'),            _('open help menu')),
     (_('Control-Z, F2'), _('switch to shell')),
     (_('Control-L, F3'), _('redraw screen')),
-    (_('Control-T, F4'), _('toggle color on and off')),
+    )
+
+SERIAL_GLOBAL_HELP_KEYS = (
+    (_('Control-T, F4'), _('toggle rich mode (colour, unicode) on and off')),
     )
 
 DRY_RUN_KEYS = (
@@ -194,7 +197,10 @@ class GlobalKeyStretchy(Stretchy):
 
     def __init__(self, app):
         rows = []
-        for key, text in GLOBAL_KEYS:
+        keys = GLOBAL_KEYS
+        if app.opts.run_on_serial:
+            keys += SERIAL_GLOBAL_HELP_KEYS
+        for key, text in keys:
             rows.append(TableRow([Text(_(key)), Text(_(text))]))
         if app.opts.dry_run:
             dro = _('(dry-run only)')
@@ -243,12 +249,9 @@ class HelpMenu(WidgetWrap):
             _("Keyboard shortcuts"), on_press=self._shortcuts)
         drop_to_shell = menu_item(
             _("Enter shell"), on_press=self._debug_shell)
-        color = menu_item(
-            _("Toggle color on/off"), on_press=self._toggle_color)
         buttons = {
             about,
             close,
-            color,
             drop_to_shell,
             keys,
             }
@@ -256,6 +259,10 @@ class HelpMenu(WidgetWrap):
             ssh_help = menu_item(
                 _("Help on SSH access"), on_press=self._ssh_help)
             buttons.add(ssh_help)
+        if self.parent.app.opts.run_on_serial:
+            rich = menu_item(
+                _("Toggle rich mode"), on_press=self._toggle_rich)
+            buttons.add(rich)
         local_title, local_doc = parent.app.ui.body.local_help()
         if local_title is not None:
             local = menu_item(
@@ -290,9 +297,10 @@ class HelpMenu(WidgetWrap):
         if self.parent.ssh_password is not None:
             entries.append(ssh_help)
 
+        if self.parent.app.opts.run_on_serial:
             entries.extend([
                 hline,
-            color,
+                rich,
                 ])
 
         rows = [
@@ -404,8 +412,8 @@ class HelpMenu(WidgetWrap):
     def _debug_shell(self, sender):
         self.parent.app.debug_shell()
 
-    def _toggle_color(self, sender):
-        self.parent.app.toggle_color()
+    def _toggle_rich(self, sender):
+        self.parent.app.toggle_rich()
 
     def _show_errors(self, sender):
         self._show_overlay(ErrorReportListStretchy(self.parent.app))

subiquitycore/core.py

@@ -112,7 +112,7 @@ urwid_8_names = (
 )
 
 
-def make_palette(colors, styles, ascii):
+def make_palette(colors, styles):
     """Return a palette to be passed to MainLoop.
 
     colors is a list of exactly 8 tuples (name, (r, g, b))
@@ -133,16 +133,6 @@ def make_palette(colors, styles, ascii):
     urwid_palette = []
     for name, fg, bg in styles:
         urwid_fg, urwid_bg = urwid_name[fg], urwid_name[bg]
-        if ascii:
-            # 24bit grey on colored background looks good
-            # but in 16 colors it's unreadable
-            # hence add more contrast
-            if urwid_bg != 'black':
-                urwid_fg = 'black'
-            # Only frame_button doesn't match above rule
-            # fix it to be brown-on-black black-on-brown
-            if name == 'frame_button focus':
-                urwid_fg, urwid_bg = 'brown', 'black'
         urwid_palette.append((name, urwid_fg, urwid_bg))
 
     return urwid_palette
@@ -348,8 +338,10 @@ class Application:
             if not opts.dry_run:
                 open('/run/casper-no-prompt', 'w').close()
 
-        self.is_color = False
-        self.color_palette = make_palette(self.COLORS, self.STYLES, opts.ascii)
+        # Set rich_mode to the opposite of what we want, so we can
+        # call toggle_rich to get the right things set up.
+        self.rich_mode = opts.run_on_serial
+        self.color_palette = make_palette(self.COLORS, self.STYLES)
 
         self.is_linux_tty = is_linux_tty()
 
@@ -557,13 +549,16 @@ class Application:
 
         self.aio_loop.call_later(0.06, _run_script)
 
-    def toggle_color(self):
-        if self.is_color:
+    def toggle_rich(self):
+        if self.rich_mode:
+            urwid.util.set_encoding('ascii')
             new_palette = self.STYLES_MONO
-            self.is_color = False
+            self.rich_mode = False
         else:
+            urwid.util.set_encoding('utf-8')
             new_palette = self.color_palette
-            self.is_color = True
+            self.rich_mode = True
+        urwid.CanvasCache.clear()
         self.urwid_loop.screen.register_palette(new_palette)
         self.urwid_loop.screen.clear()
 
@@ -572,8 +567,8 @@ class Application:
             self.exit()
         elif key == 'f3':
             self.urwid_loop.screen.clear()
-        elif key in ['ctrl t', 'f4']:
-            self.toggle_color()
+        elif self.opts.run_on_serial and key in ['ctrl t', 'f4']:
+            self.toggle_rich()
 
     def start_controllers(self):
         log.debug("starting controllers")
@@ -655,12 +650,9 @@ class Application:
             unhandled_input=self.unhandled_input,
             event_loop=AsyncioEventLoop(loop=self.aio_loop))
 
-        if self.opts.ascii:
-            urwid.util.set_encoding('ascii')
-
         extend_dec_special_charmap()
 
-        self.toggle_color()
+        self.toggle_rich()
 
         self.base_model = self.make_model()
         try: