[FIX] Select Columns: Drag/drop

Orange/widgets/data/owselectcolumns.py

@@ -5,10 +5,10 @@
 from AnyQt.QtWidgets import QWidget, QGridLayout
 from AnyQt.QtWidgets import QListView  # pylint: disable=unused-import
 from AnyQt.QtCore import (
-    Qt, QTimer, QSortFilterProxyModel, QItemSelection, QItemSelectionModel
+    Qt, QTimer, QSortFilterProxyModel, QItemSelection, QItemSelectionModel,
+    QMimeData
 )
 
-from Orange.util import deprecated
 from Orange.widgets import gui, widget
 from Orange.widgets.data.contexthandlers import \
     SelectAttributesDomainContextHandler
@@ -41,43 +41,59 @@ def source_indexes(indexes, view):
         return indexes
 
 
-# owloadcorpus in orange3-text used this
-@deprecated('Orange.widgets.utils.itemmodels.VariableListModel')
-def VariablesListItemModel(*args, **kwargs):
-    return VariableListModel(*args, enable_dnd=True, **kwargs)
+class VariablesListItemModel(VariableListModel):
+    """
+    An Variable list item model specialized for Drag and Drop.
+    """
+    MIME_TYPE = "application/x-Orange-VariableListModelData"
 
+    def flags(self, index):
+        flags = super().flags(index)
+        if index.isValid():
+            flags |= Qt.ItemIsDragEnabled
+        else:
+            flags |= Qt.ItemIsDropEnabled
+        return flags
 
-class ClassVarListItemModel(VariableListModel):
-    def dropMimeData(self, mime, action, row, column, parent):
-        """ Ensure only one variable can be dropped onto the view.
-        """
-        vars = mime.property('_items')
-        if vars is None:
-            return False
-        if action == Qt.IgnoreAction:
-            return True
-        return VariableListModel.dropMimeData(
-            self, mime, action, row, column, parent)
+    def supportedDropActions(self):
+        return Qt.MoveAction  # pragma: no cover
 
+    def supportedDragActions(self):
+        return Qt.MoveAction  # pragma: no cover
 
-class ClassVariableItemView(VariablesListItemView):
-    def __init__(self, parent=None, acceptedType=Orange.data.Variable):
-        VariablesListItemView.__init__(self, parent, acceptedType)
-        self.setDropIndicatorShown(False)
+    def mimeTypes(self):
+        return [self.MIME_TYPE]
 
-    def acceptsDropEvent(self, event):
+    def mimeData(self, indexlist):
         """
-        Reimplemented
+        Reimplemented.
 
-        Ensure only one variable is in the model.
+        For efficiency reasons only the variable instances are set on the
+        mime data (under `'_items'` property)
         """
-        accepts = super().acceptsDropEvent(event)
-        mime = event.mimeData()
-        vars = mime.property('_items')
-        if vars is None:
-            return False
+        items = [self[index.row()] for index in indexlist]
+        mime = QMimeData()
+        # the encoded 'data' is empty, variables are passed by properties
+        mime.setData(self.MIME_TYPE, b'')
+        mime.setProperty("_items", items)
+        return mime
+
+    def dropMimeData(self, mime, action, row, column, parent):
+        """
+        Reimplemented.
+        """
+        if action == Qt.IgnoreAction:
+            return True  # pragma: no cover
+        if not mime.hasFormat(self.MIME_TYPE):
+            return False  # pragma: no cover
+        variables = mime.property("_items")
+        if variables is None:
+            return False  # pragma: no cover
+        if row < 0:
+            row = self.rowCount()
 
-        return accepts
+        self[row:row] = variables
+        return True
 
 
 class OWSelectAttributes(widget.OWWidget):
@@ -126,7 +142,7 @@ def update_on_change(view):
         box = gui.vBox(self.controlArea, "Available Variables",
                        addToLayout=False)
 
-        self.available_attrs = VariableListModel(enable_dnd=True)
+        self.available_attrs = VariablesListItemModel()
         filter_edit, self.available_attrs_view = variables_filter(
             parent=self, model=self.available_attrs)
         box.layout().addWidget(filter_edit)
@@ -143,7 +159,7 @@ def dropcompleted(action):
         layout.addWidget(box, 0, 0, 3, 1)
 
         box = gui.vBox(self.controlArea, "Features", addToLayout=False)
-        self.used_attrs = VariableListModel(enable_dnd=True)
+        self.used_attrs = VariablesListItemModel()
         self.used_attrs_view = VariablesListItemView(
             acceptedType=(Orange.data.DiscreteVariable,
                           Orange.data.ContinuousVariable))
@@ -156,8 +172,8 @@ def dropcompleted(action):
         layout.addWidget(box, 0, 2, 1, 1)
 
         box = gui.vBox(self.controlArea, "Target Variable", addToLayout=False)
-        self.class_attrs = ClassVarListItemModel(enable_dnd=True)
-        self.class_attrs_view = ClassVariableItemView(
+        self.class_attrs = VariablesListItemModel()
+        self.class_attrs_view = VariablesListItemView(
             acceptedType=(Orange.data.DiscreteVariable,
                           Orange.data.ContinuousVariable))
         self.class_attrs_view.setModel(self.class_attrs)
@@ -169,7 +185,7 @@ def dropcompleted(action):
         layout.addWidget(box, 1, 2, 1, 1)
 
         box = gui.vBox(self.controlArea, "Meta Attributes", addToLayout=False)
-        self.meta_attrs = VariableListModel(enable_dnd=True)
+        self.meta_attrs = VariablesListItemModel()
         self.meta_attrs_view = VariablesListItemView(
             acceptedType=Orange.data.Variable)
         self.meta_attrs_view.setModel(self.meta_attrs)

Orange/widgets/data/tests/test_owselectcolumns.py

@@ -1,13 +1,16 @@
 from unittest import TestCase
 from unittest.mock import Mock
+
+from AnyQt.QtCore import Qt
+
 from Orange.data import Table, ContinuousVariable, DiscreteVariable, Domain
 from Orange.widgets.data.contexthandlers import \
     SelectAttributesDomainContextHandler
 from Orange.widgets.settings import ContextSetting
 from Orange.widgets.utils import vartype
 from Orange.widgets.tests.base import WidgetTest
 from Orange.widgets.data.owselectcolumns \
-    import OWSelectAttributes
+    import OWSelectAttributes, VariablesListItemModel
 
 Continuous = vartype(ContinuousVariable())
 Discrete = vartype(DiscreteVariable())
@@ -98,6 +101,28 @@ def test_open_context_with_no_match(self):
         self.assertEqual(widget.domain_role_hints, {})
 
 
+class TestModel(TestCase):
+    def test_drop_mime(self):
+        iris = Table("iris")
+        m = VariablesListItemModel(iris.domain.variables)
+        mime = m.mimeData([m.index(1, 0)])
+        self.assertTrue(mime.hasFormat(VariablesListItemModel.MIME_TYPE))
+        assert m.dropMimeData(mime, Qt.MoveAction, 5, 0, m.index(-1, -1))
+        self.assertIs(m[5], m[1])
+        assert m.dropMimeData(mime, Qt.MoveAction, -1, -1, m.index(-1, -1))
+        self.assertIs(m[6], m[1])
+
+    def test_flags(self):
+        m = VariablesListItemModel([ContinuousVariable("X")])
+        index = m.index(0)
+        flags = m.flags(m.index(0))
+        self.assertTrue(flags & Qt.ItemIsDragEnabled)
+        self.assertFalse(flags & Qt.ItemIsDropEnabled)
+        # 'invalid' index is drop enabled -> indicates insertion capability
+        flags = m.flags(m.index(-1, -1))
+        self.assertTrue(flags & Qt.ItemIsDropEnabled)
+
+
 class SimpleWidget:
     domain_role_hints = ContextSetting({})
     required = ContextSetting("", required=ContextSetting.REQUIRED)
@@ -108,6 +133,7 @@ def retrieveSpecificSettings(self):
     def storeSpecificSettings(self):
         pass
 
+
 class TestOWSelectAttributes(WidgetTest):
     def setUp(self):
         self.widget = self.create_widget(OWSelectAttributes)

Orange/widgets/utils/itemmodels.py

@@ -11,7 +11,7 @@
 
 from AnyQt.QtCore import (
     Qt, QObject, QAbstractListModel, QAbstractTableModel, QModelIndex,
-    QItemSelectionModel, QT_VERSION
+    QItemSelectionModel, QMimeData, QT_VERSION
 )
 from AnyQt.QtCore import pyqtSignal as Signal
 from AnyQt.QtGui import QColor
@@ -582,6 +582,9 @@ def setData(self, index, value, role=Qt.EditRole):
 
     def setItemData(self, index, data):
         data = dict(data)
+        if not data:
+            return True  # pragma: no cover
+
         with signal_blocking(self):
             for role, value in data.items():
                 if role == Qt.EditRole and \
@@ -752,35 +755,43 @@ def supportedDropActions(self):
         return self._supportedDropActions
 
     def mimeTypes(self):
-        return [self.MIME_TYPE] + list(QAbstractListModel.mimeTypes(self))
+        return [self.MIME_TYPE]
 
     def mimeData(self, indexlist):
         if len(indexlist) <= 0:
             return None
 
+        def itemData(row):
+            # type: (int) -> Dict[int, Any]
+            if row < len(self._other_data):
+                return {key: val for key, val in self._other_data[row].items()
+                        if isinstance(key, int)}
+            else:
+                return {}  # pragma: no cover
+
         items = [self[i.row()] for i in indexlist]
-        itemdata = [self.itemData(i) for i in indexlist]
-        mime = QAbstractListModel.mimeData(self, indexlist)
+        itemdata = [itemData(i.row()) for i in indexlist]
+        mime = QMimeData()
         mime.setData(self.MIME_TYPE, b'see properties: _items, _itemdata')
         mime.setProperty('_items', items)
         mime.setProperty('_itemdata', itemdata)
         return mime
 
     def dropMimeData(self, mime, action, row, column, parent):
         if action == Qt.IgnoreAction:
-            return True
+            return True  # pragma: no cover
 
         if not mime.hasFormat(self.MIME_TYPE):
-            return False
+            return False  # pragma: no cover
 
         items = mime.property('_items')
         itemdata = mime.property('_itemdata')
 
         if not items:
-            return False
+            return False  # pragma: no cover
 
         if row == -1:
-            row = len(self)
+            row = len(self)  # pragma: no cover
 
         self[row:row] = items
         for i, data in enumerate(itemdata):

Orange/widgets/utils/tests/test_itemmodels.py

@@ -234,6 +234,25 @@ def test_itemData(self):
 
         self.assertEqual(model.itemData(model.index(5)), {})
 
+    def test_mimeData(self):
+        model = PyListModel([1, 2])
+        model._other_data[:] = [{Qt.UserRole: "a"}, {}]
+        mime = model.mimeData([model.index(0), model.index(1)])
+        self.assertTrue(mime.hasFormat(PyListModel.MIME_TYPE))
+
+    def test_dropMimeData(self):
+        model = PyListModel([1, 2])
+        model.setData(model.index(0), "a", Qt.UserRole)
+        mime = model.mimeData([model.index(0)])
+        self.assertTrue(
+            model.dropMimeData(mime, Qt.CopyAction, 2, -1, model.index(-1, -1))
+        )
+        self.assertEqual(len(model), 3)
+        self.assertEqual(
+            model.itemData(model.index(2)),
+            {Qt.DisplayRole: 1, Qt.EditRole: 1, Qt.UserRole: "a"}
+        )
+
     def test_parent(self):
         self.assertFalse(self.model.parent(self.model.index(2)).isValid())
 
@@ -673,5 +692,6 @@ def test_read_only(self):
         self.assertRaises(TypeError, model.insertRows, 0, 0)
         self.assertRaises(TypeError, model.removeRows, 0, 0)
 
+
 if __name__ == "__main__":
     unittest.main()