convert supported_actions method into a functools.singledispatch

po/POTFILES.in

@@ -32,6 +32,7 @@ subiquity/common/api/tests/test_client.py
 subiquity/common/api/tests/test_endtoend.py
 subiquity/common/api/tests/test_server.py
 subiquity/common/errorreport.py
+subiquity/common/filesystem/actions.py
 subiquity/common/filesystem/__init__.py
 subiquity/common/filesystem/manipulator.py
 subiquity/common/filesystem/tests/__init__.py

subiquity/common/filesystem/actions.py

@@ -0,0 +1,103 @@
+# Copyright 2021 Canonical, Ltd.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import enum
+import functools
+
+from subiquitycore.gettext38 import pgettext
+
+from subiquity.models.filesystem import (
+    Bootloader,
+    Disk,
+    LVM_LogicalVolume,
+    LVM_VolGroup,
+    Partition,
+    Raid,
+    )
+
+
+class DeviceAction(enum.Enum):
+    # Information about a drive
+    INFO = pgettext("DeviceAction", "Info")
+    # Edit a device (partition, logical volume, RAID, etc)
+    EDIT = pgettext("DeviceAction", "Edit")
+    REFORMAT = pgettext("DeviceAction", "Reformat")
+    PARTITION = pgettext("DeviceAction", "Add Partition")
+    CREATE_LV = pgettext("DeviceAction", "Create Logical Volume")
+    FORMAT = pgettext("DeviceAction", "Format")
+    REMOVE = pgettext("DeviceAction", "Remove from RAID/LVM")
+    DELETE = pgettext("DeviceAction", "Delete")
+    TOGGLE_BOOT = pgettext("DeviceAction", "Make Boot Device")
+
+    def str(self):
+        return pgettext(type(self).__name__, self.value)
+
+
+@functools.singledispatch
+def supported_actions(device):
+    raise NotImplementedError(
+        "supported_actions({}) not defined".format(device))
+
+
+@supported_actions.register(Disk)
+def _disk_actions(disk):
+    actions = [
+        DeviceAction.INFO,
+        DeviceAction.REFORMAT,
+        DeviceAction.PARTITION,
+        DeviceAction.FORMAT,
+        DeviceAction.REMOVE,
+        ]
+    if disk._m.bootloader != Bootloader.NONE:
+        actions.append(DeviceAction.TOGGLE_BOOT)
+    return actions
+
+
+@supported_actions.register(Partition)
+def _part_actions(part):
+    return [
+        DeviceAction.EDIT,
+        DeviceAction.REMOVE,
+        DeviceAction.DELETE,
+        ]
+
+
+@supported_actions.register(Raid)
+def _raid_actions(raid):
+    return [
+        DeviceAction.EDIT,
+        DeviceAction.PARTITION,
+        DeviceAction.FORMAT,
+        DeviceAction.REMOVE,
+        DeviceAction.DELETE,
+        DeviceAction.REFORMAT,
+        ]
+
+
+@supported_actions.register(LVM_VolGroup)
+def _vg_actions(vg):
+    return [
+        DeviceAction.EDIT,
+        DeviceAction.CREATE_LV,
+        DeviceAction.DELETE,
+        ]
+
+
+@supported_actions.register(LVM_LogicalVolume)
+def _lv_actions(lv):
+    return [
+        DeviceAction.EDIT,
+        DeviceAction.DELETE,
+        ]

subiquity/common/filesystem/manipulator.py

@@ -15,10 +15,13 @@
 
 import logging
 
+from subiquity.common.filesystem.actions import (
+    DeviceAction,
+    supported_actions,
+    )
 from subiquity.common.types import Bootloader
 from subiquity.models.filesystem import (
     align_up,
-    DeviceAction,
     Partition,
     )
 
@@ -214,7 +217,7 @@ class FilesystemManipulator:
 
         needs_boot = self.model.needs_bootloader_partition()
         log.debug('model needs a bootloader partition? {}'.format(needs_boot))
-        can_be_boot = DeviceAction.TOGGLE_BOOT in disk.supported_actions
+        can_be_boot = DeviceAction.TOGGLE_BOOT in supported_actions(disk)
         if needs_boot and len(disk.partitions()) == 0 and can_be_boot:
             part = self._create_boot_partition(disk)
 

subiquity/common/filesystem/tests/test_manipulator.py

@@ -15,6 +15,10 @@
 
 import unittest
 
+from subiquity.common.filesystem.actions import (
+    DeviceAction,
+    supported_actions,
+    )
 from subiquity.common.filesystem.manipulator import (
     FilesystemManipulator,
     )
@@ -24,7 +28,6 @@ from subiquity.models.tests.test_filesystem import (
     )
 from subiquity.models.filesystem import (
     Bootloader,
-    DeviceAction,
     )
 
 
@@ -60,7 +63,7 @@ class TestFilesystemManipulator(unittest.TestCase):
         # manipulator around.
         for bl in Bootloader:
             manipulator, disk = make_manipulator_and_disk(bl)
-            if DeviceAction.TOGGLE_BOOT not in disk.supported_actions:
+            if DeviceAction.TOGGLE_BOOT not in supported_actions(disk):
                 continue
             manipulator.add_boot_disk(disk)
             self.assertFalse(

subiquity/models/filesystem.py

@@ -16,7 +16,6 @@
 from abc import ABC, abstractmethod
 import attr
 import collections
-import enum
 import fnmatch
 import itertools
 import logging
@@ -32,8 +31,6 @@ from curtin.util import human2bytes
 
 from probert.storage import StorageInfo
 
-from subiquitycore.gettext38 import pgettext
-
 from subiquity.common.types import Bootloader
 
 
@@ -422,23 +419,6 @@ def asdict(inst):
 # in the FilesystemModel or FilesystemController classes.
 
 
-class DeviceAction(enum.Enum):
-    # Information about a drive
-    INFO = pgettext("DeviceAction", "Info")
-    # Edit a device (partition, logical volume, RAID, etc)
-    EDIT = pgettext("DeviceAction", "Edit")
-    REFORMAT = pgettext("DeviceAction", "Reformat")
-    PARTITION = pgettext("DeviceAction", "Add Partition")
-    CREATE_LV = pgettext("DeviceAction", "Create Logical Volume")
-    FORMAT = pgettext("DeviceAction", "Format")
-    REMOVE = pgettext("DeviceAction", "Remove from RAID/LVM")
-    DELETE = pgettext("DeviceAction", "Delete")
-    TOGGLE_BOOT = pgettext("DeviceAction", "Make Boot Device")
-
-    def str(self):
-        return pgettext(type(self).__name__, self.value)
-
-
 def _generic_can_EDIT(obj):
     cd = obj.constructed_device()
     if cd is None:
@@ -586,13 +566,11 @@ class _Formattable(ABC):
         else:
             return cd
 
-    @property
-    @abstractmethod
-    def supported_actions(self):
-        pass
-
     def action_possible(self, action):
-        assert action in self.supported_actions
+        from subiquity.common.filesystem.actions import (
+            supported_actions,
+        )
+        assert action in supported_actions(self)
         r = getattr(self, "_can_" + action.name)
         if isinstance(r, bool):
             return r, None
@@ -822,19 +800,6 @@ class Disk(_Device):
         else:
             return True
 
-    @property
-    def supported_actions(self):
-        actions = [
-            DeviceAction.INFO,
-            DeviceAction.REFORMAT,
-            DeviceAction.PARTITION,
-            DeviceAction.FORMAT,
-            DeviceAction.REMOVE,
-            ]
-        if self._m.bootloader != Bootloader.NONE:
-            actions.append(DeviceAction.TOGGLE_BOOT)
-        return actions
-
     _can_INFO = True
 
     @property
@@ -1027,12 +992,6 @@ class Partition(_Formattable):
         else:
             return False
 
-    supported_actions = [
-        DeviceAction.EDIT,
-        DeviceAction.REMOVE,
-        DeviceAction.DELETE,
-        ]
-
     _can_EDIT = property(_generic_can_EDIT)
 
     _can_REMOVE = property(_generic_can_REMOVE)
@@ -1106,15 +1065,6 @@ class Raid(_Device):
     def desc(self):
         return _("software RAID {level}").format(level=self.raidlevel[4:])
 
-    supported_actions = [
-        DeviceAction.EDIT,
-        DeviceAction.PARTITION,
-        DeviceAction.FORMAT,
-        DeviceAction.REMOVE,
-        DeviceAction.DELETE,
-        DeviceAction.REFORMAT,
-        ]
-
     @property
     def _can_EDIT(self):
         if self.preserve:
@@ -1183,12 +1133,6 @@ class LVM_VolGroup(_Device):
     def desc(self):
         return _("LVM volume group")
 
-    supported_actions = [
-        DeviceAction.EDIT,
-        DeviceAction.CREATE_LV,
-        DeviceAction.DELETE,
-        ]
-
     @property
     def _can_EDIT(self):
         if self.preserve:
@@ -1247,11 +1191,6 @@ class LVM_LogicalVolume(_Formattable):
 
     label = short_label
 
-    supported_actions = [
-        DeviceAction.EDIT,
-        DeviceAction.DELETE,
-        ]
-
     _can_EDIT = True
 
     @property

subiquity/models/tests/test_filesystem.py

@@ -17,10 +17,13 @@ import unittest
 
 import attr
 
+from subiquity.common.filesystem.actions import (
+    DeviceAction,
+    supported_actions,
+    )
 from subiquity.models.filesystem import (
     Bootloader,
     dehumanize_size,
-    DeviceAction,
     Disk,
     FilesystemModel,
     get_raid_size,
@@ -376,14 +379,14 @@ class TestFilesystemModel(unittest.TestCase):
             ["to be reformatted as ext4", "mounted at /"])
 
     def assertActionNotSupported(self, obj, action):
-        self.assertNotIn(action, obj.supported_actions)
+        self.assertNotIn(action, supported_actions(obj))
 
     def assertActionPossible(self, obj, action):
-        self.assertIn(action, obj.supported_actions)
+        self.assertIn(action, supported_actions(obj))
         self.assertTrue(obj.action_possible(action)[0])
 
     def assertActionNotPossible(self, obj, action):
-        self.assertIn(action, obj.supported_actions)
+        self.assertIn(action, supported_actions(obj))
         self.assertFalse(obj.action_possible(action)[0])
 
     def _test_remove_action(self, model, objects):

subiquity/server/controllers/filesystem.py

@@ -37,6 +37,10 @@ from subiquitycore.lsb_release import lsb_release
 
 from subiquity.common.apidef import API
 from subiquity.common.errorreport import ErrorReportKind
+from subiquity.common.filesystem.actions import (
+    DeviceAction,
+    supported_actions,
+    )
 from subiquity.common.filesystem.manipulator import FilesystemManipulator
 from subiquity.common.types import (
     Bootloader,
@@ -47,7 +51,6 @@ from subiquity.common.types import (
     )
 from subiquity.models.filesystem import (
     dehumanize_size,
-    DeviceAction,
     )
 from subiquity.server.controller import (
     SubiquityController,
@@ -129,7 +132,7 @@ class FilesystemController(SubiquityController, FilesystemManipulator):
 
     def guided_lvm(self, disk, lvm_options=None):
         self.reformat(disk)
-        if DeviceAction.TOGGLE_BOOT in disk.supported_actions:
+        if DeviceAction.TOGGLE_BOOT in supported_actions(disk):
             self.add_boot_disk(disk)
         self.create_partition(
             device=disk, spec=dict(

subiquity/ui/views/filesystem/filesystem.py

@@ -60,8 +60,11 @@ from subiquitycore.ui.utils import (
     )
 from subiquitycore.view import BaseView
 
-from subiquity.models.filesystem import (
+from subiquity.common.filesystem.actions import (
     DeviceAction,
+    supported_actions,
+    )
+from subiquity.models.filesystem import (
     humanize_size,
     )
 
@@ -337,7 +340,7 @@ class DeviceList(WidgetWrap):
 
     def _action_menu_for_device(self, device):
         device_actions = []
-        for action in device.supported_actions:
+        for action in supported_actions(device):
             label_meth = getattr(
                 self, '_label_{}'.format(action.name), lambda a, d: a.str())
             label = label_meth(action, device)