[Enhancement] Better status message when adding existing repo

- Avoids freezing UI when an existing repo is added

Closes #1306

src/vorta/views/repo_add_dialog.py

@@ -1,3 +1,4 @@
+import logging
 import re
 from PyQt5 import QtCore, uic
 from PyQt5.QtWidgets import QAction, QApplication, QDialogButtonBox, QLineEdit
@@ -9,6 +10,8 @@
 from vorta.utils import borg_compat, choose_file_dialog, get_asset, get_private_keys, validate_passwords
 from vorta.views.utils import get_colored_icon
 
+logger = logging.getLogger(__name__)
+
 uifile = get_asset('UI/repoadd.ui')
 AddRepoUI, AddRepoBase = uic.loadUiType(uifile)
 
@@ -27,7 +30,7 @@ def __init__(self, parent=None):
         self.saveButton = self.buttonBox.button(QDialogButtonBox.StandardButton.Ok)
         self.saveButton.setText(self.tr("Add"))
 
-        self.buttonBox.rejected.connect(self.close)
+        self.buttonBox.rejected.connect(lambda: (self.cancel_job(), self.close()))
         self.buttonBox.accepted.connect(self.run)
         self.chooseLocalFolderButton.clicked.connect(self.choose_local_backup_folder)
         self.useRemoteRepoButton.clicked.connect(self.use_remote_repo_action)
@@ -211,6 +214,11 @@ def password_listener(self):
             self.passwordLabel.setText(translate('utils', msg))
             return not bool(msg)
 
+    def cancel_job(self):
+        if self.job:
+            self.job.cancel()
+            logger.info('Cancelled adding repo.')
+
 
 class ExistingRepoWindow(AddRepoWindow):
     def __init__(self):
@@ -242,10 +250,10 @@ def run(self):
             params = BorgInfoRepoJob.prepare(self.values)
             if params['ok']:
                 self.saveButton.setEnabled(False)
-                thread = BorgInfoRepoJob(params['cmd'], params)
-                thread.updated.connect(self._set_status)
-                thread.result.connect(self.run_result)
-                self.thread = thread  # Needs to be connected to self for tests to work.
-                self.thread.run()
+                job = BorgInfoRepoJob(params['cmd'], params)
+                job.updated.connect(self._set_status)
+                job.result.connect(self.run_result)
+                self.job = job  # Needs to be connected to self for tests to work.
+                QApplication.instance().jobs_manager.add_job(job)
             else:
                 self._set_status(params['message'])