Remove bad smell from progress dialog and handle ESC key

Fix GNS3#1120

Author: julien-duponchelle

gns3/main_window.py

@@ -94,7 +94,7 @@ def __init__(self, parent=None):
 
         MainWindow._instance = self
         self._settings = {}
-        HTTPClient.setProgressCallback(Progress().instance())
+        HTTPClient.setProgressCallback(Progress.instance(self))
 
         self._project = None
         self._createTemporaryProject()

gns3/progress.py

@@ -34,14 +34,11 @@ class Progress(QtCore.QObject):
     remove_query_signal = QtCore.Signal(str)
     progress_signal = QtCore.Signal(str, int, int)
 
-    def __init__(self, min_duration=1000):
+    def __init__(self, parent, min_duration=1000):
 
-        super().__init__()
+        super().__init__(parent)
         self._progress_dialog = None
 
-        from .main_window import MainWindow
-        self._parent = MainWindow.instance()
-
         # Timer called for refreshing the progress dialog status
         self._rtimer = QtCore.QTimer()
         self._rtimer.timeout.connect(self.update)
@@ -98,6 +95,10 @@ def _cancelSlot(self):
             for query in self._queries.copy().values():
                 query["response"].abort()
 
+    def _rejectSlot(self):
+        self._progress_dialog = None
+        self._cancelSlot()
+
     def update(self):
         if len(self._queries) == 0 and (time.time() * 1000) >= self._display_start_time + self._minimum_duration:
             self.hide()
@@ -106,8 +107,9 @@ def update(self):
 
     def show(self):
         if self._progress_dialog is None or self._progress_dialog.wasCanceled():
-            progress_dialog = QtWidgets.QProgressDialog("Waiting for server response", None, 0, 0, self._parent)
+            progress_dialog = QtWidgets.QProgressDialog("Waiting for server response", None, 0, 0, self.parent())
             progress_dialog.canceled.connect(self._cancelSlot)
+            progress_dialog.rejected.connect(self._rejectSlot)
             progress_dialog.setWindowModality(Qt.Qt.ApplicationModal)
             progress_dialog.setWindowTitle("Please wait")
             progress_dialog.setMinimumDuration(self._minimum_duration)
@@ -180,13 +182,14 @@ def context(self, **kwargs):
             self._cancel_button_text = old_cancel_button_text
 
     @staticmethod
-    def instance():
+    def instance(parent=None):
         """
         Singleton to return only one instance of Progress.
 
         :returns: instance of Progress
         """
 
         if not hasattr(Progress, "_instance") or Progress._instance is None:
-            Progress._instance = Progress()
+            Progress._instance = Progress(parent)
         return Progress._instance
+

tests/test_progress.py

@@ -19,7 +19,7 @@
 
 
 def test_context():
-    progress = Progress(min_duration=500)
+    progress = Progress(None, min_duration=500)
     assert progress._minimum_duration == 500
     assert progress._enable