Add torrent name validator on create torrent dialog

src/tribler/gui/dialogs/createtorrentdialog.py

@@ -1,7 +1,10 @@
 import os
+import re
+import typing
 
 from PyQt5 import uic
 from PyQt5.QtCore import QDir, pyqtSignal
+from PyQt5.QtGui import QValidator
 from PyQt5.QtWidgets import QAction, QFileDialog, QSizePolicy, QTreeWidgetItem
 
 from tribler.gui.defs import BUTTON_TYPE_NORMAL
@@ -17,6 +20,24 @@ def __init__(self, parent):
         QTreeWidgetItem.__init__(self, parent)
 
 
+class TorrentNameValidator(QValidator):
+    """
+    Validator used in Torrent name QLineEdit field to disallow multiline text.
+    If a new line character is detected, then it is converted to space using fixup().
+
+    Docs: https://doc.qt.io/qtforpython-5/PySide2/QtGui/QValidator.html
+    """
+    ESCAPE_CHARS_REGEX = r'[\n\r\t]'
+
+    def validate(self, text: str, pos: int) -> typing.Tuple['QValidator.State', str, int]:
+        if re.search(self.ESCAPE_CHARS_REGEX, text):
+            return QValidator.Intermediate, text, pos
+        return QValidator.Acceptable, text, pos
+
+    def fixup(self, text: str) -> str:
+        return re.sub(self.ESCAPE_CHARS_REGEX, ' ', text)
+
+
 class CreateTorrentDialog(DialogContainer):
     create_torrent_notification = pyqtSignal(dict)
     add_to_channel_selected = pyqtSignal(str)
@@ -27,6 +48,7 @@ def __init__(self, parent):
         uic.loadUi(get_ui_file_path('createtorrentdialog.ui'), self.dialog_widget)
 
         self.dialog_widget.setSizePolicy(QSizePolicy.Fixed, QSizePolicy.Expanding)
+        self.dialog_widget.create_torrent_name_field.setValidator(TorrentNameValidator(parent=self))
         connect(self.dialog_widget.btn_cancel.clicked, self.close_dialog)
         connect(self.dialog_widget.create_torrent_choose_files_button.clicked, self.on_choose_files_clicked)
         connect(self.dialog_widget.create_torrent_choose_dir_button.clicked, self.on_choose_dir_clicked)

src/tribler/gui/dialogs/tests/test_createtorrentdialog.py

@@ -0,0 +1,25 @@
+from PyQt5.QtGui import QValidator
+
+from tribler.gui.dialogs.createtorrentdialog import TorrentNameValidator
+
+
+def test_torrent_name_validator():
+    """
+    Tests if the torrent name validator marks the input as valid if there are no multiline characters.
+    Upon fixup, the invalid characters are accepted correctly.
+    """
+    def assert_text_is_valid(validator: QValidator, original_text: str, expected_to_be_valid: bool):
+        state, text, pos = validator.validate(original_text, len(original_text))
+        assert state == QValidator.Acceptable if expected_to_be_valid else QValidator.Intermediate
+        assert text == original_text
+        assert pos == len(original_text)
+
+    validator = TorrentNameValidator(None)
+
+    invalid_name = """line 1
+    line2.torrent
+    """
+    assert_text_is_valid(validator, invalid_name, expected_to_be_valid=False)
+
+    fixed_name = validator.fixup(invalid_name)
+    assert_text_is_valid(validator, fixed_name, expected_to_be_valid=True)