PR: Add Refresh button to editors from Variable Explorer

spyder/plugins/variableexplorer/widgets/collectionsdelegate.py

@@ -12,12 +12,14 @@
 import datetime
 import functools
 import operator
+from typing import Any, Callable, Optional
 
 # Third party imports
 from qtpy.compat import to_qvariant
-from qtpy.QtCore import QDateTime, Qt, Signal
-from qtpy.QtWidgets import (QAbstractItemDelegate, QDateEdit, QDateTimeEdit,
-                            QItemDelegate, QLineEdit, QMessageBox, QTableView)
+from qtpy.QtCore import QDateTime, QModelIndex, Qt, Signal
+from qtpy.QtWidgets import (
+    QAbstractItemDelegate, QDateEdit, QDateTimeEdit, QItemDelegate, QLineEdit,
+    QMessageBox, QTableView)
 from spyder_kernels.utils.lazymodules import (
     FakeObject, numpy as np, pandas as pd, PIL)
 from spyder_kernels.utils.nsview import (display_to_value, is_editable_type,
@@ -43,9 +45,15 @@ class CollectionsDelegate(QItemDelegate, SpyderFontsMixin):
     sig_editor_creation_started = Signal()
     sig_editor_shown = Signal()
 
-    def __init__(self, parent=None, namespacebrowser=None):
+    def __init__(
+        self,
+        parent=None,
+        namespacebrowser=None,
+        data_function: Optional[Callable[[], Any]] = None
+    ):
         QItemDelegate.__init__(self, parent)
         self.namespacebrowser = namespacebrowser
+        self.data_function = data_function
         self._editors = {}  # keep references on opened editors
 
     def get_value(self, index):
@@ -56,6 +64,49 @@ def set_value(self, index, value):
         if index.isValid():
             index.model().set_value(index, value)
 
+    def make_data_function(
+        self,
+        index: QModelIndex
+    ) -> Optional[Callable[[], Any]]:
+        """
+        Construct function which returns current value of data.
+
+        This is used to refresh editors created from this piece of data.
+        For instance, if `self` is the delegate for an editor that displays
+        the dict `xxx` and the user opens another editor for `xxx["aaa"]`,
+        then to refresh the data of the second editor, the nested function
+        `datafun` first gets the refreshed data for `xxx` and then gets the
+        item with key "aaa".
+
+        Parameters
+        ----------
+        index : QModelIndex
+            Index of item whose current value is to be returned by the
+            function constructed here.
+
+        Returns
+        -------
+        Optional[Callable[[], Any]]
+            Function which returns the current value of the data, or None if
+            such a function cannot be constructed.
+        """
+        if self.data_function is None:
+            return None
+        key = index.model().keys[index.row()]
+
+        def datafun():
+            data = self.data_function()
+            if isinstance(data, (tuple, list, dict, set)):
+                return data[key]
+
+            try:
+                return getattr(data, key)
+            except (NotImplementedError, AttributeError,
+                    TypeError, ValueError):
+                return None
+
+        return datafun
+
     def show_warning(self, index):
         """
         Decide if showing a warning when the user is trying to view
@@ -163,7 +214,10 @@ def createEditor(self, parent, option, index, object_explorer=False):
         elif isinstance(value, (list, set, tuple, dict)) and not object_explorer:
             from spyder.widgets.collectionseditor import CollectionsEditor
             editor = CollectionsEditor(
-                parent=parent, namespacebrowser=self.namespacebrowser)
+                parent=parent,
+                namespacebrowser=self.namespacebrowser,
+                data_function=self.make_data_function(index)
+            )
             editor.setup(value, key, icon=self.parent().windowIcon(),
                          readonly=readonly)
             self.create_dialog(editor, dict(model=index.model(), editor=editor,
@@ -174,7 +228,10 @@ def createEditor(self, parent, option, index, object_explorer=False):
                 np.ndarray is not FakeObject and not object_explorer):
             # We need to leave this import here for tests to pass.
             from .arrayeditor import ArrayEditor
-            editor = ArrayEditor(parent=parent)
+            editor = ArrayEditor(
+                parent=parent,
+                data_function=self.make_data_function(index)
+            )
             if not editor.setup_and_check(value, title=key, readonly=readonly):
                 self.sig_editor_shown.emit()
                 return
@@ -205,7 +262,10 @@ def createEditor(self, parent, option, index, object_explorer=False):
                 and pd.DataFrame is not FakeObject and not object_explorer):
             # We need to leave this import here for tests to pass.
             from .dataframeeditor import DataFrameEditor
-            editor = DataFrameEditor(parent=parent)
+            editor = DataFrameEditor(
+                parent=parent,
+                data_function=self.make_data_function(index)
+            )
             if not editor.setup_and_check(value, title=key):
                 self.sig_editor_shown.emit()
                 return
@@ -272,6 +332,7 @@ def createEditor(self, parent, option, index, object_explorer=False):
                 name=key,
                 parent=parent,
                 namespacebrowser=self.namespacebrowser,
+                data_function=self.make_data_function(index),
                 readonly=readonly)
             self.create_dialog(editor, dict(model=index.model(),
                                             editor=editor,
@@ -414,8 +475,12 @@ def updateEditorGeometry(self, editor, option, index):
 
 class ToggleColumnDelegate(CollectionsDelegate):
     """ToggleColumn Item Delegate"""
-    def __init__(self, parent=None, namespacebrowser=None):
-        CollectionsDelegate.__init__(self, parent, namespacebrowser)
+
+    def __init__(self, parent=None, namespacebrowser=None,
+                 data_function: Optional[Callable[[], Any]] = None):
+        CollectionsDelegate.__init__(
+            self, parent, namespacebrowser, data_function
+        )
         self.current_index = None
         self.old_obj = None
 
@@ -435,6 +500,51 @@ def set_value(self, index, value):
         if index.isValid():
             index.model().set_value(index, value)
 
+    def make_data_function(
+        self,
+        index: QModelIndex
+    ) -> Optional[Callable[[], Any]]:
+        """
+        Construct function which returns current value of data.
+
+        This is used to refresh editors created from this piece of data.
+        For instance, if `self` is the delegate for an editor displays the
+        object `obj` and the user opens another editor for `obj.xxx.yyy`,
+        then to refresh the data of the second editor, the nested function
+        `datafun` first gets the refreshed data for `obj` and then gets the
+        `xxx` attribute and then the `yyy` attribute.
+
+        Parameters
+        ----------
+        index : QModelIndex
+            Index of item whose current value is to be returned by the
+            function constructed here.
+
+        Returns
+        -------
+        Optional[Callable[[], Any]]
+            Function which returns the current value of the data, or None if
+            such a function cannot be constructed.
+        """
+        if self.data_function is None:
+            return None
+
+        obj_path = index.model().get_key(index).obj_path
+        path_elements = obj_path.split('.')
+        del path_elements[0]  # first entry is variable name
+
+        def datafun():
+            data = self.data_function()
+            try:
+                for attribute_name in path_elements:
+                    data = getattr(data, attribute_name)
+                return data
+            except (NotImplementedError, AttributeError,
+                    TypeError, ValueError):
+                return None
+
+        return datafun
+
     def createEditor(self, parent, option, index):
         """Overriding method createEditor"""
         if self.show_warning(index):
@@ -471,7 +581,10 @@ def createEditor(self, parent, option, index):
         if isinstance(value, (list, set, tuple, dict)):
             from spyder.widgets.collectionseditor import CollectionsEditor
             editor = CollectionsEditor(
-                parent=parent, namespacebrowser=self.namespacebrowser)
+                parent=parent,
+                namespacebrowser=self.namespacebrowser,
+                data_function=self.make_data_function(index)
+            )
             editor.setup(value, key, icon=self.parent().windowIcon(),
                          readonly=readonly)
             self.create_dialog(editor, dict(model=index.model(), editor=editor,
@@ -480,7 +593,10 @@ def createEditor(self, parent, option, index):
         # ArrayEditor for a Numpy array
         elif (isinstance(value, (np.ndarray, np.ma.MaskedArray)) and
                 np.ndarray is not FakeObject):
-            editor = ArrayEditor(parent=parent)
+            editor = ArrayEditor(
+                parent=parent,
+                data_function=self.make_data_function(index)
+            )
             if not editor.setup_and_check(value, title=key, readonly=readonly):
                 return
             self.create_dialog(editor, dict(model=index.model(), editor=editor,
@@ -501,7 +617,10 @@ def createEditor(self, parent, option, index):
         # DataFrameEditor for a pandas dataframe, series or index
         elif (isinstance(value, (pd.DataFrame, pd.Index, pd.Series))
                 and pd.DataFrame is not FakeObject):
-            editor = DataFrameEditor(parent=parent)
+            editor = DataFrameEditor(
+                parent=parent,
+                data_function=self.make_data_function(index)
+            )
             if not editor.setup_and_check(value, title=key):
                 return
             self.create_dialog(editor, dict(model=index.model(), editor=editor,