refactor: Rewrite widget exists check

src/widget/contentdialog.cpp

@@ -611,6 +611,16 @@ void ContentDialog::activate(GenericChatroomWidget* widget)
     updateTitleAndStatusIcon();
 }
 
+bool ContentDialog::containsFriend(int friendId) const
+{
+    return friendWidgets.contains(friendId);
+}
+
+bool ContentDialog::containsGroup(int groupId) const
+{
+    return groupWidgets.contains(groupId);
+}
+
 /**
  * @brief Update friend widget name and position.
  * @param friendId Friend Id.

src/widget/contentdialog.h

@@ -77,6 +77,9 @@ public:
     void focusFriend(int friendId);
     void focusGroup(int groupId);
 
+    bool containsFriend(int friendId) const;
+    bool containsGroup(int groupId) const;
+
 signals:
     void friendDialogShown(const Friend* f);
     void groupDialogShown(Group* g);

src/widget/contentdialogmanager.cpp

@@ -43,12 +43,22 @@ ContentDialog* ContentDialogManager::current()
 
 bool ContentDialogManager::friendWidgetExists(int friendId)
 {
-    return existsWidget(friendId, friendList);
+    const auto dialog = friendDialogs.value(friendId, nullptr);
+    if (dialog == nullptr) {
+        return false;
+    }
+
+    return dialog->containsFriend(friendId);
 }
 
 bool ContentDialogManager::groupWidgetExists(int groupId)
 {
-    return existsWidget(groupId, groupList);
+    const auto dialog = groupDialogs.value(groupId, nullptr);
+    if (dialog == nullptr) {
+        return false;
+    }
+
+    return dialog->containsGroup(groupId);
 }
 
 FriendWidget* ContentDialogManager::addFriendToDialog(ContentDialog* dialog,