WID-223: create global context as singleton and observer to hold shar…

…ed and reactive state between viewers and operations

tvbwidgets/ui/connectivity_ipy/connectivity_widget.py

@@ -15,7 +15,9 @@
 from tvb.datatypes.connectivity import Connectivity
 from tvbwidgets.ui.base_widget import TVBWidget
 from tvbwidgets.ui.connectivity_ipy.outputs_3d import PyVistaOutput
+from tvbwidgets.ui.connectivity_ipy.operations import ConnectivityOperations
 from tvbwidgets.ui.connectivity_ipy.config import ConnectivityConfig
+from tvbwidgets.ui.connectivity_ipy.global_context import CONTEXT
 
 DROPDOWN_KEY = 'dropdown'
 
@@ -83,14 +85,20 @@ def __draw_connectivity(self):
         def on_change(change):
             if change['type'] == 'change' and change['name'] == 'value':
                 matrix = self.connectivity.weights if change['new'] == 'weights' else self.connectivity.tract_lengths
+                CONTEXT.matrix = change['new']
                 self.__show_plot(matrix)
 
         dropdown = ipywidgets.Dropdown(
-            options=[('Tracts', 'tracts'), ('Weights', 'weights')],
-            value='weights',
+            options=CONTEXT.MATRIX_OPTIONS,
+            value=CONTEXT.matrix,
             description='Matrix:'
         )
         dropdown.observe(on_change)
+
+        def on_ctx_change(value):
+            dropdown.value = value
+
+        CONTEXT.observe(on_ctx_change, 'matrix')
         self.widgets_map[DROPDOWN_KEY] = dropdown
         self.children = (dropdown, *self.children)
 
@@ -200,22 +208,6 @@ def _extract_edges(self):
         return numpy.array(edges_coords)
 
 
-class ConnectivityOperations(ipywidgets.VBox, TVBWidget):
-    def add_datatype(self, datatype):
-        """
-        Currently not supported
-        """
-        pass
-
-    def __init__(self, connectivity, **kwargs):
-        super().__init__(layout=self.DEFAULT_BORDER, **kwargs)
-        children = [
-            ipywidgets.HTML(
-                value=f'Placeholder text for operations on Connectivity-{connectivity.number_of_regions}'
-            )]
-        self.children = children
-
-
 class ConnectivityViewers(ipywidgets.Accordion):
     def __init__(self, connectivity, **kwargs):
         super().__init__(**kwargs)

tvbwidgets/ui/connectivity_ipy/global_context.py

@@ -0,0 +1,69 @@
+# -*- coding: utf-8 -*-
+#
+# "TheVirtualBrain - Widgets" package
+#
+# (c) 2022-2023, TVB Widgets Team
+#
+from typing import Callable
+
+
+class SingletonMeta(type):
+    _instances = {}
+
+    def __call__(cls, *args, **kwargs):
+        if cls not in cls._instances:
+            cls._instances[cls] = super().__call__(*args, **kwargs)
+        return cls._instances[cls]
+
+
+class GlobalContext(metaclass=SingletonMeta):
+    MATRIX_OPTIONS = [('Tracts', 'tracts'), ('Weights', 'weights')]
+    _observed_state = dict()
+
+    def __init__(self):
+        self._matrix = 'weights'
+
+    @property
+    def matrix(self):
+        return self._matrix
+
+    @matrix.setter
+    def matrix(self, value):
+        old_value = self._matrix
+        self._matrix = value
+        if old_value == value:
+            return
+        try:
+            observers = self._observed_state['matrix']
+            for observer in observers:
+                observer(value)
+        except KeyError:
+            pass
+
+    def observe(self, observer_func, value_observed):
+        # type: (Callable[[any], any], str) -> None
+        """
+        Method to register an observer for the specified value.
+        When the specified value changes (if the value is set to the same as previous,
+         observers are not triggered), all registered observers ar called
+        with the new value passed as param.
+        """
+        try:
+            observers_list = self._observed_state[value_observed]
+            observers_list.append(observer_func)
+        except KeyError:
+            self._observed_state[value_observed] = [observer_func]
+
+    def remove_observer(self, observer_func, value_observed):
+        # type: (Callable[[any], any], str) -> None
+        """
+        Unregister a registered observer.
+        """
+        try:
+            observers_list = self._observed_state[value_observed]
+            observers_list.remove(observer_func)
+        except KeyError:
+            pass
+
+
+CONTEXT = GlobalContext()

tvbwidgets/ui/connectivity_ipy/operations.py

@@ -0,0 +1,81 @@
+# -*- coding: utf-8 -*-
+#
+# "TheVirtualBrain - Widgets" package
+#
+# (c) 2022-2023, TVB Widgets Team
+#
+import ipywidgets
+from tvbwidgets.ui.base_widget import TVBWidget
+from tvbwidgets.ui.connectivity_ipy.global_context import CONTEXT
+
+
+class ConnectivityOperations(ipywidgets.VBox, TVBWidget):
+    def add_datatype(self, datatype):
+        """
+        Currently not supported
+        """
+        pass
+
+    def __init__(self, connectivity, **kwargs):
+        super().__init__(layout={**self.DEFAULT_BORDER, 'width': '50%'}, **kwargs)
+        self.connectivity = connectivity
+        selector = self.__get_node_selector()
+        children = [
+            ipywidgets.HTML(
+                value=f'<h3>Operations for Connectivity-{connectivity.number_of_regions}</h3>'
+            ), selector]
+        self.children = children
+        self.regions_checkboxes = []
+
+    def __get_node_selector(self):
+        left_children = []
+        right_children = []
+        region_labels = self.connectivity.region_labels
+        # print('region labels: ', region_labels)
+        for region in region_labels:
+            label = str(region)
+            selector = ipywidgets.Checkbox(value=False, description=label, layout={'width': 'max-content'},
+                                           indent=False)
+            if label.startswith('l'):
+                left_children.append(selector)
+            else:
+                right_children.append(selector)
+
+        self.regions_checkboxes = [*left_children, *right_children]
+
+        left = ipywidgets.VBox(children=(ipywidgets.HTML('<p>Left hemisphere</p>'),
+                                         ipywidgets.VBox(children=left_children,
+                                                         )),
+                               layout={'width': '50%', 'align-items': 'start'}
+                               )
+        right = ipywidgets.VBox(children=(ipywidgets.HTML('<p>Right hemisphere</p>'),
+                                          ipywidgets.VBox(children=right_children,
+                                                          )),
+                                layout={'width': '50%', 'align-items': 'start'}
+                                )
+        matrix_dropdown = ipywidgets.Dropdown(
+            options=CONTEXT.MATRIX_OPTIONS,
+            value=CONTEXT.matrix,
+            description='Matrix:'
+        )
+
+        def on_change(value):
+            CONTEXT.matrix = value['new']
+
+        matrix_dropdown.observe(on_change, 'value')
+
+        def on_ctx_change(value):
+            matrix_dropdown.value = value
+
+        CONTEXT.observe(on_ctx_change, 'matrix')
+
+        container = ipywidgets.VBox(children=(matrix_dropdown,
+                                              ipywidgets.HBox(children=(left, right))))
+        accordion = ipywidgets.Accordion(children=[container], selected_index=None,
+                                         layout={'height': '50vh'})
+        accordion.set_title(0, 'Regions selector')
+        return accordion
+
+    @property
+    def selected_regions(self):
+        return map(lambda x: x.description, filter(lambda x: x.value, self.regions_checkboxes))