Fixes related to Export Data dialog

CHANGES.md

@@ -56,6 +56,11 @@ v0.13.4 (unreleased)
 * Improve performance when updating links and changing attributes
   on subsets. [#1716]
 
+* Fix errors that happened when clicking on the 'Export Data' and
+  'Define arithmetic attributes' buttons when no data was present,
+  and fixed Qt errors that happened if the data collection changed
+  after the 'Export Data' dialog was opened. [#1795]
+
 * Fixed parsing of AVM meta-data from images. [#1732]
 
 v0.13.3 (unreleased)

glue/app/qt/application.py

@@ -363,7 +363,6 @@ def _setup_ui(self):
         self._button_link_data.setIcon(get_icon('glue_link'))
         self._button_link_data.setToolButtonStyle(Qt.ToolButtonTextBesideIcon)
         self._button_link_data.clicked.connect(self._set_up_links)
-        self._on_data_collection_change()
 
         self._data_toolbar.addWidget(self._button_link_data)
 
@@ -409,6 +408,8 @@ def _setup_ui(self):
 
         self.addToolBar(self._data_toolbar)
 
+        self._on_data_collection_change()
+
         # Selection mode toolbar
 
         tbar = EditSubsetModeToolBar(parent=self)
@@ -452,7 +453,9 @@ def _setup_ui(self):
         self._hub.subscribe(self, DataCollectionMessage, handler=self._on_data_collection_change)
 
     def _on_data_collection_change(self, *event):
+        self._button_save_data.setEnabled(len(self.data_collection) > 0)
         self._button_link_data.setEnabled(len(self.data_collection) > 1)
+        self._button_edit_components.setEnabled(len(self.data_collection) > 0)
 
     def keyPressEvent(self, event):
         if self.current_tab.activeSubWindow() and self.current_tab.activeSubWindow().widget():

glue/app/qt/save_data.py

@@ -80,7 +80,7 @@ def __init__(self, data_collection=None, parent=None):
 
         self.ui = load_ui('save_data.ui', parent=self,
                           directory=os.path.dirname(__file__))
-        autoconnect_callbacks_to_qt(self.state, self)
+        autoconnect_callbacks_to_qt(self.state, self.ui)
 
         self.ui.button_cancel.clicked.connect(self.reject)
         self.ui.button_ok.clicked.connect(self.accept)

glue/core/data_combo_helper.py

@@ -374,18 +374,18 @@ def refresh(self, *args):
         self.choices = choices
 
     def _filter_msg(self, msg):
-        return msg.data in self._data or msg.sender in self._data_collection
+        return msg.sender in self._data
 
     def register_to_hub(self, hub):
         hub.subscribe(self, DataRenameComponentMessage,
                       handler=self._on_rename,
-                      filter=lambda msg: msg.sender in self._data)
+                      filter=self._filter_msg)
         hub.subscribe(self, DataReorderComponentMessage,
                       handler=self.refresh,
-                      filter=lambda msg: msg.sender in self._data)
+                      filter=self._filter_msg)
         hub.subscribe(self, ComponentsChangedMessage,
                       handler=self.refresh,
-                      filter=lambda msg: msg.sender in self._data)
+                      filter=self._filter_msg)
         if self._data_collection is not None:
             hub.subscribe(self, DataCollectionDeleteMessage,
                           handler=self._remove_data)
@@ -535,16 +535,25 @@ def remove_data(self, data):
         self._datasets.remove(data)
         self.refresh()
 
+    def _remove_data_msg(self, msg):
+        self.remove_data(msg.data)
+
+    def _filter_msg(self, msg):
+        return msg.sender in self._datasets
+
+    def _filter_msg_dc(self, msg):
+        return msg.sender is self._data_collection
+
     def register_to_hub(self, hub):
 
         super(ManualDataComboHelper, self).register_to_hub(hub)
 
         hub.subscribe(self, DataUpdateMessage,
                       handler=self._on_data_update,
-                      filter=lambda msg: msg.sender in self._datasets)
+                      filter=self._filter_msg)
         hub.subscribe(self, DataCollectionDeleteMessage,
-                      handler=lambda msg: self.remove_data(msg.data),
-                      filter=lambda msg: msg.sender is self._data_collection)
+                      handler=self._remove_data_msg,
+                      filter=self._filter_msg_dc)
 
 
 class DataCollectionComboHelper(BaseDataComboHelper):
@@ -571,14 +580,20 @@ def __init__(self, state, selection_property, data_collection):
 
         self.refresh()
 
+    def _filter_msg_in(self, msg):
+        return msg.sender in self._datasets
+
+    def _filter_msg_is(self, msg):
+        return msg.sender is self._datasets
+
     def register_to_hub(self, hub):
         super(DataCollectionComboHelper, self).register_to_hub(hub)
         hub.subscribe(self, DataUpdateMessage,
                       handler=self._on_data_update,
-                      filter=lambda msg: msg.sender in self._datasets)
+                      filter=self._filter_msg_in)
         hub.subscribe(self, DataCollectionAddMessage,
                       handler=self.refresh,
-                      filter=lambda msg: msg.sender is self._datasets)
+                      filter=self._filter_msg_is)
         hub.subscribe(self, DataCollectionDeleteMessage,
                       handler=self.refresh,
-                      filter=lambda msg: msg.sender is self._datasets)
+                      filter=self._filter_msg_is)

glue/external/echo/core.py

@@ -188,6 +188,16 @@ def remove_callback(self, instance, func):
         else:
             raise ValueError("Callback function not found: %s" % func)
 
+    def clear_callbacks(self, instance):
+        """
+        Remove all callbacks on this property.
+        """
+        for cb in [self._callbacks, self._2arg_callbacks]:
+            if instance in cb:
+                cb[instance].clear()
+        if instance in self._disabled:
+            self._disabled.pop(instance)
+
 
 class HasCallbackProperties(object):
     """
@@ -346,6 +356,14 @@ def iter_callback_properties(self):
     def callback_properties(self):
         return [name for name in dir(self) if self.is_callback_property(name)]
 
+    def clear_callbacks(self):
+        """
+        Remove all global and property-specific callbacks.
+        """
+        self._global_callbacks.clear()
+        for name, prop in self.iter_callback_properties():
+            prop.clear_callbacks(self)
+
 
 def add_callback(instance, prop, callback, echo_old=False, priority=0):
     """