Avoid some context crashes: exclude_attributes=True

Some contexts match even though feature-selection combo boxes do not
show the feature. Problematic settings are those where combo boxes are
limited to specific parts of the table (attributes, class_vars, or
metas).

This does not solve the problem completely, but if problem appears,
adding a new widget instance allows the user to continue.

Also, there is another minor issue: exclude_attributes won't allow users
to reuse contexts where class vars were used in the fields (current
implementation handles attributes and class vars in the same way), but
saving and loading works properly (because of perfect matches).

orangecontrib/spectroscopy/widgets/owbin.py

@@ -46,7 +46,7 @@ class Warning(OWWidget.Warning):
 
     settingsHandler = DomainContextHandler()
 
-    attrs = ContextSetting([None, None])
+    attrs = ContextSetting([None, None], exclude_attributes=True)
     bin_shape = settings.Setting((1, 1))
     square_bin = settings.Setting(True)
 

orangecontrib/spectroscopy/widgets/owhyper.py

@@ -623,8 +623,8 @@ class ImagePlot(QWidget, OWComponent, SelectionGroupMixin,
                 ImageColorSettingMixin, ImageRGBSettingMixin,
                 ImageZoomMixin, ConcurrentMixin):
 
-    attr_x = ContextSetting(None)
-    attr_y = ContextSetting(None)
+    attr_x = ContextSetting(None, exclude_attributes=True)
+    attr_y = ContextSetting(None, exclude_attributes=True)
     gamma = Setting(0)
 
     selection_changed = Signal()

orangecontrib/spectroscopy/widgets/owsnr.py

@@ -31,8 +31,10 @@ class Outputs:
                    'Standard Deviation': 2} # std
 
     settingsHandler = settings.DomainContextHandler()
-    group_x = settings.ContextSetting(None)
-    group_y = settings.ContextSetting(None)
+    group_x = settings.ContextSetting(None, exclude_attributes=True,
+                                      exclude_class_vars=True)
+    group_y = settings.ContextSetting(None, exclude_attributes=True,
+                                      exclude_class_vars=True)
     out_choiced = settings.Setting(0)
 
     autocommit = settings.Setting(True)

orangecontrib/spectroscopy/widgets/owspectra.py

@@ -892,7 +892,7 @@ class CurvePlot(QWidget, OWComponent, SelectionGroupMixin):
 
     sample_seed = Setting(0, schema_only=True)
     peak_labels_saved = Setting([], schema_only=True)
-    feature_color = ContextSetting(None)
+    feature_color = ContextSetting(None, exclude_attributes=True)
     color_individual = Setting(False)  # color individual curves (in a cycle) if no feature_color
     invertX = Setting(False)
     viewtype = Setting(INDIVIDUAL)

orangecontrib/spectroscopy/widgets/owspectralseries.py

@@ -33,7 +33,7 @@
 class LineScanPlot(QWidget, OWComponent, SelectionGroupMixin,
                    ImageColorSettingMixin, ImageZoomMixin):
 
-    attr_x = ContextSetting(None)
+    attr_x = ContextSetting(None, exclude_attributes=True)
     gamma = Setting(0)
 
     selection_changed = Signal()

orangecontrib/spectroscopy/widgets/owstackalign.py

@@ -141,8 +141,8 @@ class Error(OWWidget.Error):
     settingsHandler = DomainContextHandler()
 
     sobel_filter = settings.Setting(False)
-    attr_x = ContextSetting(None)
-    attr_y = ContextSetting(None)
+    attr_x = ContextSetting(None, exclude_attributes=True)
+    attr_y = ContextSetting(None, exclude_attributes=True)
     ref_frame_num = settings.Setting(0)
 
     def __init__(self):