Fix #1059. Ensure display item not changed by selecting graphics. Test.

nion/swift/DisplayPanel.py

@@ -2651,11 +2651,17 @@ def nudge_selected_graphics(self, mapping: Graphics.CoordinateMappingLike, delta
 
     def adjust_graphics(self, widget_mapping: Graphics.CoordinateMappingLike, graphic_drag_items: typing.Sequence[Graphics.Graphic], graphic_drag_part: str, graphic_part_data: typing.Dict[int, Graphics.DragPartData], graphic_drag_start_pos: Geometry.FloatPoint, pos: Geometry.FloatPoint, modifiers: UserInterface.KeyboardModifiers) -> None:
         if self.__display_item:
-            with self.__display_item.display_item_changes():
-                for graphic in graphic_drag_items:
-                    index = self.__display_item.graphics.index(graphic)
-                    part_data = (graphic_drag_part, ) + graphic_part_data[index]
-                    graphic.adjust_part(widget_mapping, graphic_drag_start_pos, pos, part_data, modifiers)
+            graphic_changed = False
+            for graphic in graphic_drag_items:
+                index = self.__display_item.graphics.index(graphic)
+                part_data = (graphic_drag_part, ) + graphic_part_data[index]
+                graphic_modified = graphic.modified_count
+                graphic.adjust_part(widget_mapping, graphic_drag_start_pos, pos, part_data, modifiers)
+                if graphic.modified_count != graphic_modified:
+                    graphic_changed = True
+            if graphic_changed:
+                self.__display_item._begin_display_item_changes()
+                self.__display_item._end_display_item_changes()
 
     def nudge_slice(self, delta: int) -> None:
         display_data_channel = self.__display_item.display_data_channel if self.__display_item else None

nion/swift/test/DisplayPanel_test.py

@@ -1641,6 +1641,43 @@ def test_image_display_canvas_item_only_updates_once_if_graphic_changes(self):
             graphic.bounds = Geometry.FloatRect.from_tlbr(0.1, 0.1, 0.2, 0.2)
             self.assertEqual(update_count + 1, display_panel.display_canvas_item._update_count)
 
+    def test_image_display_canvas_item_does_not_update_if_graphic_does_not_change(self):
+        # confirm that clicking on a graphic does not change the display item (causing it or its thumbnail to redraw).
+        with TestContext.create_memory_context() as test_context:
+            document_controller = test_context.create_document_controller()
+            document_model = document_controller.document_model
+            display_panel = document_controller.selected_display_panel
+            data_item = DataItem.DataItem(numpy.random.randn(8, 8))
+            document_model.append_data_item(data_item)
+            display_item = document_model.get_display_item_for_data_item(data_item)
+            graphic = Graphics.RectangleGraphic()
+            display_item.add_graphic(graphic)
+            display_panel.set_display_panel_display_item(display_item)
+            display_panel.root_container.layout_immediate(Geometry.IntSize(240, 240))
+            document_controller.periodic()
+            self.assertIsInstance(display_panel.display_canvas_item, ImageCanvasItem.ImageCanvasItem)
+            document_controller.periodic()
+            # click once
+            display_panel.display_canvas_item.simulate_click(Geometry.IntPoint(120, 120))
+            document_controller.periodic()
+            update_count = display_panel.display_canvas_item._update_count
+
+            display_item_did_change = False
+
+            def item_changed() -> None:
+                nonlocal display_item_did_change
+                display_item_did_change = True
+
+            with display_item.item_changed_event.listen(item_changed):
+                # click again, nothing should change. use explicit press/release to perform periodic.
+                display_panel.display_canvas_item.simulate_press(Geometry.IntPoint(120, 120))
+                document_controller.periodic()
+                display_panel.display_canvas_item.simulate_release(Geometry.IntPoint(120, 120))
+                document_controller.periodic()
+                self.assertEqual(update_count, display_panel.display_canvas_item._update_count)
+
+            self.assertFalse(display_item_did_change)
+
     def test_image_display_canvas_item_only_updates_once_if_color_map_changes(self):
         with TestContext.create_memory_context() as test_context:
             document_controller = test_context.create_document_controller()