Track expanded packages outside of packages themseleves

Packages now retain their expanded/collapsed state after the
packagelist has been regenerated.

package_manager/__init__.py

@@ -55,7 +55,6 @@ class ConsolidatedPackage:
 
     def __init__(self, pkg=None):
         self.versions = []
-        self.expanded = False
 
         if pkg is not None:
             self.add_version(pkg)
@@ -600,6 +599,7 @@ class USERPREF_PT_packages(bpy.types.Panel):
     available_packages = []
     installed_packages = []
     displayed_packages = []
+    expanded_packages = []
 
     @classmethod
     def poll(cls, context):
@@ -773,6 +773,7 @@ class USERPREF_PT_packages(bpy.types.Panel):
                         draw_version(subvbox, version)
 
             pkg = metapkg.get_latest_version()
+            is_expanded = (pkg.name in self.expanded_packages)
 
             pkgbox = layout.box()
             spl = pkgbox.split(.8)
@@ -783,10 +784,9 @@ class USERPREF_PT_packages(bpy.types.Panel):
             right.alignment = 'RIGHT'
             right.scale_y = 1.5
 
-            # for collapse/expand button
             left.operator(
                     WM_OT_package_toggle_expand.bl_idname,
-                    icon='TRIA_DOWN' if metapkg.expanded else 'TRIA_RIGHT',
+                    icon='TRIA_DOWN' if is_expanded else 'TRIA_RIGHT',
                     emboss=False,
                     ).package_name=pkg.name
 
@@ -812,7 +812,7 @@ class USERPREF_PT_packages(bpy.types.Panel):
                 else:
                     right.label("Not installed, but no URL?")
 
-            if metapkg.expanded:
+            if is_expanded:
                 expanded()
             else:
                 collapsed()# }}}
@@ -862,18 +862,12 @@ class WM_OT_package_toggle_expand(bpy.types.Operator):
             )
 
     def invoke(self, context, event):
-        global _packages
-        try:
-            pkg = _packages[self.package_name]
-        except KeyError:
-            log.error("Couldn't find package '%s'", self.package_name)
-            return {'CANCELLED'}
-        
-        pkg.expanded = not pkg.expanded
         if event.shift:
-            for pkgname in USERPREF_PT_packages.displayed_packages:
-                if not pkgname == self.package_name:
-                    _packages[pkgname].expanded = False
+            USERPREF_PT_packages.expanded_packages = []
+        if self.package_name in USERPREF_PT_packages.expanded_packages:
+            USERPREF_PT_packages.expanded_packages.remove(self.package_name)
+        else:
+            USERPREF_PT_packages.expanded_packages.append(self.package_name)
 
         return {'FINISHED'}