Differentiated between user packages and system packages

We usually can't uninstall system packages, so display them
differently

Also fixed some missing `global`s.

package_manager/__init__.py

@@ -87,7 +87,10 @@ class SubprocMixin:
 
     def quit(self):
         """Signals the state machine to stop this operator from running."""
-        self.cancel(bpy.context)
+        try:
+            self.cancel(bpy.context)
+        except AttributeError:
+            pass
         self._state = 'QUIT'
 
     def invoke(self, context, event):
@@ -312,7 +315,7 @@ class PACKAGE_OT_uninstall(SubprocMixin, bpy.types.Operator):
         import pathlib
         install_path = pathlib.Path(bpy.utils.user_resource('SCRIPTS', 'addons', create=True))
 
-        # TODO: only drawing-related package data should be stored on the panel. Maybe move this to a global..?
+        global _packages
         package = _packages[self.package_name].get_latest_version()
 
         proc = multiprocessing.Process(target=subproc.uninstall,
@@ -364,6 +367,7 @@ class PACKAGE_OT_refresh_packages(bpy.types.Operator):
     log = logging.getLogger(__name__ + ".PACKAGE_OT_refresh_packages")
 
     def execute(self, context):
+        global _packages
         installed_packages = get_packages_from_disk(refresh=True)
         available_packages = get_packages_from_repo()
         _packages = build_composite_packagelist(installed_packages, available_packages)
@@ -443,6 +447,7 @@ class PACKAGE_OT_refresh_repositories(SubprocMixin, bpy.types.Operator):
         for pkg in available_packages:
             pkg.repository = result.repository.name
 
+        global _packages
         _packages = build_composite_packagelist(installed_packages, available_packages)
         self.report({'INFO'}, 'Package list retrieved successfully')
 
@@ -793,7 +798,12 @@ class USERPREF_PT_packages(bpy.types.Panel):
                     right.operator(PACKAGE_OT_uninstall.bl_idname,
                             text="Uninstall").package_name=pkg.name
                 else:
-                    right.label("Installed")
+                    right.scale_y = 2
+                    if pkg.user:
+                        right.label("Installed")
+                    else:
+                        l = right.label("System package")
+                        right.enabled = False
             else:
                 if pkg.url:
                     right.operator(PACKAGE_OT_install.bl_idname,
@@ -908,6 +918,26 @@ def build_composite_packagelist(installed: list, available: list) -> OrderedDict
         return pkg1.version == pkg2.version\
             and pkg1.files == pkg2.files
 
+    def is_user_package(pkg: Package) -> bool:
+        """Check if package's install location is in user scripts path or preferences scripts path"""
+        from pathlib import Path
+
+        user_script_path = bpy.utils.script_path_user()
+        prefs_script_path = bpy.utils.script_path_pref()
+
+        if user_script_path is not None:
+            in_user = Path(user_script_path) in Path(pkg.installed_location).parents
+        else:
+            in_user = False
+
+        if prefs_script_path is not None:
+            in_prefs = Path(prefs_script_path) in Path(pkg.installed_location).parents
+        else:
+            in_prefs = False
+
+        return in_user or in_prefs
+
+
     for pkg in available:
         pkgname = pkg.bl_info['name']
         if pkgname in masterlist:
@@ -917,9 +947,9 @@ def build_composite_packagelist(installed: list, available: list) -> OrderedDict
 
     for pkg in installed:
         pkg.installed = True
+        pkg.user = is_user_package(pkg)
         if pkg.name in masterlist:
             for masterpkg in masterlist[pkg.name]:
-                # log.debug("{} and {} equivilent? {}".format((pkg.name, pkg.version), (masterpkg.name, masterpkg.version), packages_are_equivilent(pkg, masterpkg)))
                 if packages_are_equivilent(pkg, masterpkg):
                     masterpkg.installed = True
                     masterpkg.installed_location = pkg.installed_location

package_manager/utils.py

@@ -0,0 +1,15 @@
+from pathlib import Path
+
+def parse_repository_url(url: str) -> str:
+    """Sanitize repository url"""
+    from urllib.parse import urlsplit, urlunsplit
+    parsed_url = urlsplit(url)
+    new_path = parsed_url.path.rstrip("repo.json")
+    return urlunsplit((parsed_url.scheme, parsed_url.netloc, new_path, parsed_url.query, parsed_url.fragment))
+
+def add_repojson_to_url(url: str) -> str:
+    """Add repo.json to a url"""
+    from urllib.parse import urlsplit, urlunsplit
+    parsed_url = urlsplit(url)
+    new_path = str(Path(parsed_url.path) / "repo.json")
+    return urlunsplit((parsed_url.scheme, parsed_url.netloc, new_path, parsed_url.query, parsed_url.fragment))