Settings: its rows in five groups

Settings had grown to 21 rows in one list. It opens on five groups (This
device, Display, GNSS and radio, Network, System); Enter opens one, Back
returns to the groups, and Back from the groups leaves Settings.

SettingsMenu holds the groups and which one is open (host-tested: every
setting is in exactly one group). The guide, the how-tos, the README,
the scripts' messages and the firmware's own name the new paths, such as
"Settings > System > Firmware".

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0162FokPdvY2KsS4NBfwyWPk

lib/apps_model/src/settings_menu.cpp

@@ -16,19 +16,50 @@ struct RowDef {
     const char* label;
 };
 
-const RowDef kRows[] = {
-    {Row::LongName, Kind::Text, "Long name"},   {Row::ShortName, Kind::Text, "Short name"},
-    {Row::Region, Kind::Choice, "Region"},      {Row::Timezone, Kind::Choice, "Timezone"},
-    {Row::Brightness, Kind::Slider, "Brightness"}, {Row::DimTimeout, Kind::Choice, "Dim after"},
-    {Row::OffTimeout, Kind::Choice, "Screen off after"}, {Row::Launcher, Kind::Toggle, "Launcher"},
-    {Row::Theme, Kind::Choice, "Theme"}, {Row::ThemeLight, Kind::Toggle, "Light or dark"}, {Row::Sound, Kind::Toggle, "Sound & LED"},
-    {Row::Gnss, Kind::Toggle, "GNSS"}, {Row::GnssQuiet, Kind::Toggle, "Pause GNSS for LoRa"},
-    {Row::Coordinates, Kind::Toggle, "Coordinates"},
-    {Row::ProbeMacs, Kind::Toggle, "Probe MACs"}, {Row::Wifi, Kind::Page, "Wi-Fi"},
-    {Row::CheckUpdates, Kind::Toggle, "Check for updates"}, {Row::Firmware, Kind::Page, "Firmware"},
-    {Row::Vpn, Kind::Page, "VPN"},
-    {Row::DebugConsole, Kind::Page, "Debug Console"}, {Row::About, Kind::Page, "About"},
+const RowDef kGroups[] = {
+    {Row::GroupDevice, Kind::Group, "This device"},  {Row::GroupDisplay, Kind::Group, "Display"},
+    {Row::GroupPosition, Kind::Group, "GNSS and radio"}, {Row::GroupNetwork, Kind::Group, "Network"},
+    {Row::GroupSystem, Kind::Group, "System"},
 };
+constexpr int kGroupCount = sizeof(kGroups) / sizeof(kGroups[0]);
+
+struct Member {
+    int group;  // an index into kGroups
+    RowDef def;
+};
+
+// In the order each group lists them.
+const Member kRows[] = {
+    {0, {Row::LongName, Kind::Text, "Long name"}},
+    {0, {Row::ShortName, Kind::Text, "Short name"}},
+    {0, {Row::Region, Kind::Choice, "Region"}},
+    {0, {Row::Timezone, Kind::Choice, "Timezone"}},
+    {0, {Row::Sound, Kind::Toggle, "Sound & LED"}},
+    {1, {Row::Brightness, Kind::Slider, "Brightness"}},
+    {1, {Row::DimTimeout, Kind::Choice, "Dim after"}},
+    {1, {Row::OffTimeout, Kind::Choice, "Screen off after"}},
+    {1, {Row::Theme, Kind::Choice, "Theme"}},
+    {1, {Row::ThemeLight, Kind::Toggle, "Light or dark"}},
+    {1, {Row::Launcher, Kind::Toggle, "Launcher"}},
+    {2, {Row::Gnss, Kind::Toggle, "GNSS"}},
+    {2, {Row::GnssQuiet, Kind::Toggle, "Pause GNSS for LoRa"}},
+    {2, {Row::Coordinates, Kind::Toggle, "Coordinates"}},
+    {2, {Row::ProbeMacs, Kind::Toggle, "Probe MACs"}},
+    {3, {Row::Wifi, Kind::Page, "Wi-Fi"}},
+    {3, {Row::Vpn, Kind::Page, "VPN"}},
+    {4, {Row::CheckUpdates, Kind::Toggle, "Check for updates"}},
+    {4, {Row::Firmware, Kind::Page, "Firmware"}},
+    {4, {Row::DebugConsole, Kind::Page, "Debug Console"}},
+    {4, {Row::About, Kind::Page, "About"}},
+};
+
+// Row i of what is listed: a group, or the i-th row of the open one.
+const RowDef& at(int group, int i) {
+    if (group < 0) return kGroups[i < 0 || i >= kGroupCount ? 0 : i];
+    for (const Member& m : kRows)
+        if (m.group == group && i-- == 0) return m.def;
+    return kGroups[group];  // out of range: harmless
+}
 
 const int kDimSeconds[] = {10, 15, 30, 60, 120, 300};
 const int kOffSeconds[] = {30, 60, 120, 300, 600, 1800};
@@ -65,10 +96,42 @@ int indexOf(const int (&table)[N], int value) {
 
 }  // namespace
 
-int SettingsMenu::count() const { return sizeof(kRows) / sizeof(kRows[0]); }
-SettingsMenu::Row SettingsMenu::row(int i) const { return kRows[i].row; }
-SettingsMenu::Kind SettingsMenu::kind(int i) const { return kRows[i].kind; }
-std::string SettingsMenu::label(int i) const { return kRows[i].label; }
+bool SettingsMenu::open(int i) {
+    if (group_ >= 0 || i < 0 || i >= kGroupCount) return false;
+    group_ = lastGroup_ = i;
+    return true;
+}
+
+bool SettingsMenu::close() {
+    if (group_ < 0) return false;
+    group_ = -1;
+    return true;
+}
+
+std::string SettingsMenu::title() const { return group_ < 0 ? "" : kGroups[group_].label; }
+
+bool SettingsMenu::reveal(Row r, int& index) {
+    int seen[kGroupCount] = {};
+    for (const Member& m : kRows) {
+        if (m.def.row == r) {
+            group_ = lastGroup_ = m.group;
+            index = seen[m.group];
+            return true;
+        }
+        seen[m.group]++;
+    }
+    return false;
+}
+
+int SettingsMenu::count() const {
+    if (group_ < 0) return kGroupCount;
+    int n = 0;
+    for (const Member& m : kRows) n += m.group == group_;
+    return n;
+}
+SettingsMenu::Row SettingsMenu::row(int i) const { return at(group_, i).row; }
+SettingsMenu::Kind SettingsMenu::kind(int i) const { return at(group_, i).kind; }
+std::string SettingsMenu::label(int i) const { return at(group_, i).label; }
 
 std::string SettingsMenu::value(int i) const {
     switch (row(i)) {