all_channels: Implement "All channels" page

Fixes #188.

See Figma:
  https://www.figma.com/design/1JTNtYo9memgW7vV6d0ygq/Zulip-Mobile?node-id=7723-6411&m=dev

Notable features not included here:

- Colorizing unsubscribed channels, #1848
- "New channel", #1572
- The ability to view archived channels

Author: chrisbobbe

assets/l10n/app_en.arb

@@ -72,6 +72,18 @@
   "@chooseAccountButtonAddAnAccount": {
     "description": "Label for ChooseAccountPage button to add an account"
   },
+  "navButtonAllChannels": "All channels",
+  "@navButtonAllChannels": {
+    "description": "Title for a nav button that opens the 'All channels' page."
+  },
+  "allChannelsPageTitle": "All channels",
+  "@allChannelsPageTitle": {
+    "description": "Title for the 'All channels' page."
+  },
+  "allChannelsEmptyPlaceholder": "There are no channels you can view in this organization.",
+  "@allChannelsEmptyPlaceholder": {
+    "description": "Centered text on the 'All channels' page saying that there is no content to show."
+  },
   "profileButtonSendDirectMessage": "Send direct message",
   "@profileButtonSendDirectMessage": {
     "description": "Label for button in profile screen to navigate to DMs with the shown user."
@@ -1078,6 +1090,13 @@
   "@channelsEmptyPlaceholder": {
     "description": "Centered text on the 'Channels' page saying that there is no content to show."
   },
+  "channelsEmptyPlaceholderWithAllChannelsLink": "You’re not subscribed to any channels yet. Try going to <z-link>{allChannelsPageTitle}</z-link> and joining some of them.",
+  "@channelsEmptyPlaceholderWithAllChannelsLink": {
+    "description": "Centered text on the 'Channels' page saying that there is no content to show, with a link to 'All channels'.",
+    "placeholders": {
+      "allChannelsPageTitle": {"type": "String", "example": "All channels"}
+    }
+  },
   "sharePageTitle": "Share",
   "@sharePageTitle": {
     "description": "Title for the page about sharing content received from other apps."

lib/generated/l10n/zulip_localizations.dart

@@ -239,6 +239,24 @@ abstract class ZulipLocalizations {
   /// **'Add an account'**
   String get chooseAccountButtonAddAnAccount;
 
+  /// Title for a nav button that opens the 'All channels' page.
+  ///
+  /// In en, this message translates to:
+  /// **'All channels'**
+  String get navButtonAllChannels;
+
+  /// Title for the 'All channels' page.
+  ///
+  /// In en, this message translates to:
+  /// **'All channels'**
+  String get allChannelsPageTitle;
+
+  /// Centered text on the 'All channels' page saying that there is no content to show.
+  ///
+  /// In en, this message translates to:
+  /// **'There are no channels you can view in this organization.'**
+  String get allChannelsEmptyPlaceholder;
+
   /// Label for button in profile screen to navigate to DMs with the shown user.
   ///
   /// In en, this message translates to:
@@ -1591,6 +1609,14 @@ abstract class ZulipLocalizations {
   /// **'You’re not subscribed to any channels yet.'**
   String get channelsEmptyPlaceholder;
 
+  /// Centered text on the 'Channels' page saying that there is no content to show, with a link to 'All channels'.
+  ///
+  /// In en, this message translates to:
+  /// **'You’re not subscribed to any channels yet. Try going to <z-link>{allChannelsPageTitle}</z-link> and joining some of them.'**
+  String channelsEmptyPlaceholderWithAllChannelsLink(
+    String allChannelsPageTitle,
+  );
+
   /// Title for the page about sharing content received from other apps.
   ///
   /// In en, this message translates to:

lib/generated/l10n/zulip_localizations_ar.dart

@@ -67,6 +67,16 @@ class ZulipLocalizationsAr extends ZulipLocalizations {
   @override
   String get chooseAccountButtonAddAnAccount => 'Add an account';
 
+  @override
+  String get navButtonAllChannels => 'All channels';
+
+  @override
+  String get allChannelsPageTitle => 'All channels';
+
+  @override
+  String get allChannelsEmptyPlaceholder =>
+      'There are no channels you can view in this organization.';
+
   @override
   String get profileButtonSendDirectMessage => 'Send direct message';
 
@@ -900,6 +910,13 @@ class ZulipLocalizationsAr extends ZulipLocalizations {
   String get channelsEmptyPlaceholder =>
       'You’re not subscribed to any channels yet.';
 
+  @override
+  String channelsEmptyPlaceholderWithAllChannelsLink(
+    String allChannelsPageTitle,
+  ) {
+    return 'You’re not subscribed to any channels yet. Try going to <z-link>$allChannelsPageTitle</z-link> and joining some of them.';
+  }
+
   @override
   String get sharePageTitle => 'Share';
 

lib/generated/l10n/zulip_localizations_de.dart

@@ -67,6 +67,16 @@ class ZulipLocalizationsDe extends ZulipLocalizations {
   @override
   String get chooseAccountButtonAddAnAccount => 'Account hinzufügen';
 
+  @override
+  String get navButtonAllChannels => 'All channels';
+
+  @override
+  String get allChannelsPageTitle => 'All channels';
+
+  @override
+  String get allChannelsEmptyPlaceholder =>
+      'There are no channels you can view in this organization.';
+
   @override
   String get profileButtonSendDirectMessage => 'Direktnachricht senden';
 
@@ -923,6 +933,13 @@ class ZulipLocalizationsDe extends ZulipLocalizations {
   @override
   String get channelsEmptyPlaceholder => 'Du hast noch keine Kanäle abonniert.';
 
+  @override
+  String channelsEmptyPlaceholderWithAllChannelsLink(
+    String allChannelsPageTitle,
+  ) {
+    return 'You’re not subscribed to any channels yet. Try going to <z-link>$allChannelsPageTitle</z-link> and joining some of them.';
+  }
+
   @override
   String get sharePageTitle => 'Teilen';
 

lib/generated/l10n/zulip_localizations_en.dart

@@ -67,6 +67,16 @@ class ZulipLocalizationsEn extends ZulipLocalizations {
   @override
   String get chooseAccountButtonAddAnAccount => 'Add an account';
 
+  @override
+  String get navButtonAllChannels => 'All channels';
+
+  @override
+  String get allChannelsPageTitle => 'All channels';
+
+  @override
+  String get allChannelsEmptyPlaceholder =>
+      'There are no channels you can view in this organization.';
+
   @override
   String get profileButtonSendDirectMessage => 'Send direct message';
 
@@ -900,6 +910,13 @@ class ZulipLocalizationsEn extends ZulipLocalizations {
   String get channelsEmptyPlaceholder =>
       'You’re not subscribed to any channels yet.';
 
+  @override
+  String channelsEmptyPlaceholderWithAllChannelsLink(
+    String allChannelsPageTitle,
+  ) {
+    return 'You’re not subscribed to any channels yet. Try going to <z-link>$allChannelsPageTitle</z-link> and joining some of them.';
+  }
+
   @override
   String get sharePageTitle => 'Share';
 

lib/generated/l10n/zulip_localizations_fr.dart

@@ -68,6 +68,16 @@ class ZulipLocalizationsFr extends ZulipLocalizations {
   @override
   String get chooseAccountButtonAddAnAccount => 'Ajouter un compte';
 
+  @override
+  String get navButtonAllChannels => 'All channels';
+
+  @override
+  String get allChannelsPageTitle => 'All channels';
+
+  @override
+  String get allChannelsEmptyPlaceholder =>
+      'There are no channels you can view in this organization.';
+
   @override
   String get profileButtonSendDirectMessage => 'Envoyer un message direct';
 
@@ -914,6 +924,13 @@ class ZulipLocalizationsFr extends ZulipLocalizations {
   String get channelsEmptyPlaceholder =>
       'You’re not subscribed to any channels yet.';
 
+  @override
+  String channelsEmptyPlaceholderWithAllChannelsLink(
+    String allChannelsPageTitle,
+  ) {
+    return 'You’re not subscribed to any channels yet. Try going to <z-link>$allChannelsPageTitle</z-link> and joining some of them.';
+  }
+
   @override
   String get sharePageTitle => 'Share';
 

lib/generated/l10n/zulip_localizations_it.dart

@@ -67,6 +67,16 @@ class ZulipLocalizationsIt extends ZulipLocalizations {
   @override
   String get chooseAccountButtonAddAnAccount => 'Aggiungi un account';
 
+  @override
+  String get navButtonAllChannels => 'All channels';
+
+  @override
+  String get allChannelsPageTitle => 'All channels';
+
+  @override
+  String get allChannelsEmptyPlaceholder =>
+      'There are no channels you can view in this organization.';
+
   @override
   String get profileButtonSendDirectMessage => 'Invia un messaggio diretto';
 
@@ -915,6 +925,13 @@ class ZulipLocalizationsIt extends ZulipLocalizations {
   String get channelsEmptyPlaceholder =>
       'Non sei ancora iscritto ad alcun canale.';
 
+  @override
+  String channelsEmptyPlaceholderWithAllChannelsLink(
+    String allChannelsPageTitle,
+  ) {
+    return 'You’re not subscribed to any channels yet. Try going to <z-link>$allChannelsPageTitle</z-link> and joining some of them.';
+  }
+
   @override
   String get sharePageTitle => 'Share';
 

lib/generated/l10n/zulip_localizations_ja.dart

@@ -66,6 +66,16 @@ class ZulipLocalizationsJa extends ZulipLocalizations {
   @override
   String get chooseAccountButtonAddAnAccount => '新しいアカウントを追加';
 
+  @override
+  String get navButtonAllChannels => 'All channels';
+
+  @override
+  String get allChannelsPageTitle => 'All channels';
+
+  @override
+  String get allChannelsEmptyPlaceholder =>
+      'There are no channels you can view in this organization.';
+
   @override
   String get profileButtonSendDirectMessage => 'ダイレクトメッセージを送信';
 
@@ -879,6 +889,13 @@ class ZulipLocalizationsJa extends ZulipLocalizations {
   @override
   String get channelsEmptyPlaceholder => 'まだ参加しているチャンネルはありません。';
 
+  @override
+  String channelsEmptyPlaceholderWithAllChannelsLink(
+    String allChannelsPageTitle,
+  ) {
+    return 'You’re not subscribed to any channels yet. Try going to <z-link>$allChannelsPageTitle</z-link> and joining some of them.';
+  }
+
   @override
   String get sharePageTitle => '共有';
 

lib/generated/l10n/zulip_localizations_nb.dart

@@ -67,6 +67,16 @@ class ZulipLocalizationsNb extends ZulipLocalizations {
   @override
   String get chooseAccountButtonAddAnAccount => 'Add an account';
 
+  @override
+  String get navButtonAllChannels => 'All channels';
+
+  @override
+  String get allChannelsPageTitle => 'All channels';
+
+  @override
+  String get allChannelsEmptyPlaceholder =>
+      'There are no channels you can view in this organization.';
+
   @override
   String get profileButtonSendDirectMessage => 'Send direct message';
 
@@ -900,6 +910,13 @@ class ZulipLocalizationsNb extends ZulipLocalizations {
   String get channelsEmptyPlaceholder =>
       'You’re not subscribed to any channels yet.';
 
+  @override
+  String channelsEmptyPlaceholderWithAllChannelsLink(
+    String allChannelsPageTitle,
+  ) {
+    return 'You’re not subscribed to any channels yet. Try going to <z-link>$allChannelsPageTitle</z-link> and joining some of them.';
+  }
+
   @override
   String get sharePageTitle => 'Share';
 

lib/generated/l10n/zulip_localizations_pl.dart

@@ -67,6 +67,16 @@ class ZulipLocalizationsPl extends ZulipLocalizations {
   @override
   String get chooseAccountButtonAddAnAccount => 'Dodaj konto';
 
+  @override
+  String get navButtonAllChannels => 'All channels';
+
+  @override
+  String get allChannelsPageTitle => 'All channels';
+
+  @override
+  String get allChannelsEmptyPlaceholder =>
+      'There are no channels you can view in this organization.';
+
   @override
   String get profileButtonSendDirectMessage => 'Wyślij wiadomość bezpośrednią';
 
@@ -914,6 +924,13 @@ class ZulipLocalizationsPl extends ZulipLocalizations {
   @override
   String get channelsEmptyPlaceholder => 'Nie śledzisz żadnego z kanałów.';
 
+  @override
+  String channelsEmptyPlaceholderWithAllChannelsLink(
+    String allChannelsPageTitle,
+  ) {
+    return 'You’re not subscribed to any channels yet. Try going to <z-link>$allChannelsPageTitle</z-link> and joining some of them.';
+  }
+
   @override
   String get sharePageTitle => 'Udostępnij';