Add a message if you're trying to type without being logged in

Fix #484

src/providers/twitch/twitchaccountmanager.cpp

@@ -137,6 +137,17 @@ void TwitchAccountManager::load()
     });
 }
 
+bool TwitchAccountManager::isLoggedIn() const
+{
+    if (!this->currentUser) {
+        return false;
+    }
+
+    // Once `TwitchAccount` class has a way to check, we should also return false if the credentials
+    // are incorrect
+    return !this->currentUser->isAnon();
+}
+
 bool TwitchAccountManager::removeUser(TwitchAccount *account)
 {
     const auto &accs = this->accounts.getVector();

src/providers/twitch/twitchaccountmanager.hpp

@@ -47,6 +47,8 @@ public:
     void reloadUsers();
     void load();
 
+    bool isLoggedIn() const;
+
     pajlada::Settings::Setting<std::string> currentUsername = {"/accounts/current", ""};
     pajlada::Signals::NoArgSignal currentUserChanged;
     pajlada::Signals::NoArgSignal userListUpdated;

src/providers/twitch/twitchchannel.cpp

@@ -142,6 +142,15 @@ void TwitchChannel::sendMessage(const QString &message)
 {
     auto app = getApp();
 
+    if (!app->accounts->twitch.isLoggedIn()) {
+        // XXX: It would be nice if we could add a link here somehow that opened the "account
+        // manager" dialog
+        this->addMessage(
+            messages::Message::createSystemMessage("You need to log in to send messages. You can "
+                                                   "link your Twitch account in the settings."));
+        return;
+    }
+
     debug::Log("[TwitchChannel:{}] Send message: {}", this->name, message);
 
     // Do last message processing