add context handler

Orange/widgets/unsupervised/owkmeans.py

@@ -18,7 +18,7 @@
 from Orange.preprocess import Normalize
 from Orange.preprocess.impute import ReplaceUnknowns
 from Orange.widgets import widget, gui
-from Orange.widgets.settings import Setting, ContextSetting
+from Orange.widgets.settings import Setting, ContextSetting, ContextHandler
 from Orange.widgets.utils.annotated_data import \
     ANNOTATED_DATA_SIGNAL_NAME, add_columns
 from Orange.widgets.utils.concurrent import ThreadExecutor, FutureSetWatcher
@@ -99,6 +99,18 @@ class NotEnoughData(ValueError):
     pass
 
 
+class TableTypeContextHandler(ContextHandler):
+    def new_context(self, tabletype):
+        context = super().new_context()
+        context.tabletype = tabletype
+        return context
+
+    def match(self, context, tabletype):
+        if context.tabletype == tabletype:
+            return self.MATCH
+        return self.NO_MATCH
+
+
 class OWKMeans(widget.OWWidget):
     name = "k-Means"
     description = "k-Means clustering algorithm with silhouette-based " \
@@ -140,6 +152,7 @@ class Warning(widget.OWWidget.Warning):
 
     resizing_enabled = False
 
+    settingsHandler = TableTypeContextHandler()
     k = Setting(3)
     k_from = Setting(2)
     k_to = Setting(8)
@@ -589,6 +602,7 @@ def send_data(self):
     @Inputs.data
     @check_sql_input
     def set_data(self, data):
+        self.closeContext()
         self.data, old_data = data, self.data
         self.selection = None
         self.controls.normalize.setDisabled(
@@ -611,6 +625,7 @@ def set_data(self, data):
                 self.send_data()
         else:
             self.invalidate(unconditional=True)
+        self.openContext(str(type(data)))
 
     def send_report(self):
         # False positives (Setting is not recognized as int)