Fixed comma appended to username completion when not at the beginning of the message (#3060)

Co-authored-by: pajlada <rasmus.karlsson@pajlada.com>

src/widgets/helper/ResizingTextEdit.cpp

@@ -39,6 +39,19 @@ bool ResizingTextEdit::hasHeightForWidth() const
     return true;
 }
 
+bool ResizingTextEdit::isFirstWord() const
+{
+    QString plainText = this->toPlainText();
+    for (int i = this->textCursor().position(); i >= 0; i--)
+    {
+        if (plainText[i] == ' ')
+        {
+            return false;
+        }
+    }
+    return true;
+};
+
 int ResizingTextEdit::heightForWidth(int) const
 {
     auto margins = this->contentsMargins();
@@ -108,17 +121,6 @@ void ResizingTextEdit::keyPressEvent(QKeyEvent *event)
         }
 
         QString currentCompletionPrefix = this->textUnderCursor();
-        bool isFirstWord = [&] {
-            QString plainText = this->toPlainText();
-            for (int i = this->textCursor().position(); i >= 0; i--)
-            {
-                if (plainText[i] == ' ')
-                {
-                    return false;
-                }
-            }
-            return true;
-        }();
 
         // check if there is something to complete
         if (currentCompletionPrefix.size() <= 1)
@@ -134,7 +136,8 @@ void ResizingTextEdit::keyPressEvent(QKeyEvent *event)
             // First type pressing tab after modifying a message, we refresh our
             // completion model
             this->completer_->setModel(completionModel);
-            completionModel->refresh(currentCompletionPrefix, isFirstWord);
+            completionModel->refresh(currentCompletionPrefix,
+                                     this->isFirstWord());
             this->completionInProgress_ = true;
             this->completer_->setCompletionPrefix(currentCompletionPrefix);
             this->completer_->complete();