snaplist: add visual indication for starred publishers

In addition to verified publishers being indicated by a check-mark, we
now have starred publishers indicated with a circled star.

If unicode support is not available, for instance with serial
connections, we use a different number of stars to represent:

 * verified publishers: 2 stars
 * starred publishers: 1 star
 * others: no star

Because our mechanism to substitute unicode characters with ascii
equivalents expect a 1:1 mapping, we cannot simply replace the circled
start by two stars. To workaround the issue, we added a narrow
non-breakable space.

When support of unicode is available, this character shows up as a
normal space.
When support of unicode is not available, it gets replaced by a star.

Signed-off-by: Olivier Gayot <olivier.gayot@canonical.com>

examples/snaps/v2-find-name=mosquitto.json

@@ -15,7 +15,7 @@
         "id": "l5m6dy7O2H7mosoJSwmhRa2ZA0H6yGt1",
         "username": "ralight",
         "display-name": "Roger Light",
-        "validation": "unproven"
+        "validation": "starred"
       },
       "developer": "ralight",
       "status": "available",

examples/snaps/v2-find-name=prometheus.json

@@ -14,7 +14,7 @@
         "id": "IJ1Iesv3hhEPHuegj7b3zvPLOh8wZs34",
         "username": "jacek",
         "display-name": "Jacek Nykis",
-        "validation": "unproven"
+        "validation": "starred"
       },
       "developer": "jacek",
       "status": "available",

examples/snaps/v2-find-section=server.json

@@ -1527,7 +1527,7 @@
         "id": "l5m6dy7O2H7mosoJSwmhRa2ZA0H6yGt1",
         "username": "ralight",
         "display-name": "Roger Light",
-        "validation": "unproven"
+        "validation": "starred"
       },
       "developer": "ralight",
       "status": "available",
@@ -2213,7 +2213,7 @@
         "id": "IJ1Iesv3hhEPHuegj7b3zvPLOh8wZs34",
         "username": "jacek",
         "display-name": "Jacek Nykis",
-        "validation": "unproven"
+        "validation": "starred"
       },
       "developer": "jacek",
       "status": "available",

subiquity/common/types.py

@@ -385,6 +385,7 @@ class SnapInfo:
     summary: str = ''
     publisher: str = ''
     verified: bool = False
+    starred: bool = False
     description: str = ''
     confinement: str = ''
     license: str = ''

subiquity/models/snaplist.py

@@ -54,6 +54,7 @@ class SnapListModel:
         snap.summary = data['summary']
         snap.publisher = data['developer']
         snap.verified = data['publisher']['validation'] == "verified"
+        snap.starred = data['publisher']['validation'] == "starred"
         snap.description = data['description']
         snap.confinement = data['confinement']
         snap.license = data['license']

subiquity/ui/views/snaplist.py

@@ -182,7 +182,11 @@ class SnapInfoView(WidgetWrap):
 
         publisher = [('info_minor', _("by: ")), snap.publisher]
         if snap.verified:
-            publisher.append(('verified', ' \N{check mark}'))
+            # Check extend_dec_special_charmap for the meaning of the
+            # narrow non-breakable space here.
+            publisher.append(('verified', ' \N{check mark}\N{NNBSP}'))
+        elif snap.starred:
+            publisher.append(' \N{circled white star}')
 
         title = Columns([
             Text(snap.name),
@@ -433,9 +437,13 @@ class SnapListView(BaseView):
                 continue
             box = self.snap_boxes[snap.name] = SnapCheckBox(
                 self, snap, snap.name in self.selections_by_name)
-            publisher = snap.publisher
+            publisher = [snap.publisher]
             if snap.verified:
-                publisher = [publisher, ('verified', '\N{check mark}')]
+                # Check extend_dec_special_charmap for the meaning of the
+                # narrow non-breakable space here.
+                publisher.append(('verified', '\N{check mark}\N{NNBSP}'))
+            elif snap.starred:
+                publisher.append('\N{circled white star}')
             row = [
                 box,
                 Text(publisher),

subiquitycore/tui.py

@@ -46,12 +46,18 @@ def extend_dec_special_charmap():
         ord('\N{BLACK LEFT-POINTING SMALL TRIANGLE}'): '<',
         ord('\N{BLACK DOWN-POINTING SMALL TRIANGLE}'): 'v',
         ord('\N{BLACK UP-POINTING SMALL TRIANGLE}'): '^',
-        ord('\N{check mark}'): '+',
+        ord('\N{check mark}'): '*',
+        ord('\N{circled white star}'): '*',
         ord('\N{bullet}'): '*',
         ord('\N{lower half block}'): '=',
         ord('\N{upper half block}'): '=',
         ord('\N{FULL BLOCK}'): urwid.escape.DEC_SPECIAL_CHARMAP[
             ord('\N{BOX DRAWINGS LIGHT VERTICAL}')],
+        # XXX: Hack to show the verified snap publishers with two stars when
+        # unicode is not supported. In rich mode, we display ✪ followed by a
+        # mostly invisible character (i.e., NNBSP). In basic mode,
+        # both characters get translated to a star, resulting in two stars.
+        ord('\N{NNBSP}'): '*',
     })