Collection Manager: Fix scrolling issue. Task: T69577

Set the selection to the collection when clicking on its expander.
This prevents the tree view scrolling changing when expanding/collapsing
subcollections.

This also sets the selection to the first collection when collapsing
all collections to prevent loosing the selected row and then later
adding collections to some unknown region.

object_collection_manager/__init__.py

@@ -22,7 +22,7 @@ bl_info = {
     "name": "Collection Manager",
     "description": "Manage collections and their objects",
     "author": "Ryan Inch",
-    "version": (2, 7, 24),
+    "version": (2, 7, 25),
     "blender": (2, 80, 0),
     "location": "View3D - Object Mode (Shortcut - M)",
     "warning": '',  # used for warning icon and text in addons panel

object_collection_manager/operators.py

@@ -105,6 +105,7 @@ class ExpandAllOperator(Operator):
 
         if len(expanded) > 0:
             expanded.clear()
+            context.scene.collection_manager.cm_list_index = 0
         else:
             for laycol in layer_collections.values():
                 if laycol["ptr"].children:
@@ -204,6 +205,9 @@ class ExpandSublevelOperator(Operator):
             expand_history["target"] = ""
             expand_history["history"].clear()
 
+        # set the selected row to the collection you're expanding/collapsing to
+        # preserve the tree view's scrolling
+        context.scene.collection_manager.cm_list_index = self.index
 
         #update tree view
         update_property_group(context)