ui: redraw screens after moving from one screen to another

Wieh urwid > 2.1.2, the screen is only redrawn after urwid handles an
event (e.g., keypress, resize, ...) or an urwid alarm (it is like a
timer).

All other changes made to the UI do not trigger a screen redraw. We now
redraw the screen properly after moving from one screen to another.

Signed-off-by: Olivier Gayot <olivier.gayot@canonical.com>

DESIGN.md

@@ -270,10 +270,10 @@ class ExampleController(SubiquityTuiController):
         return ExampleView(self, thing)
 
     def cancel(self):
-        self.app.prev_screen()
+        self.app.request_prev_screen()
 
     def done(self, thing):
-        self.app.next_screen(self.endpoint.POST(thing))
+        self.app.request_next_screen(self.endpoint.POST(thing))
 ```
 
 Setting `endpoint_name` means that self.client gets set to an implementation of

console_conf/controllers/chooser.py

@@ -70,7 +70,7 @@ class RecoveryChooserController(RecoveryChooserBaseController):
 
     def select(self, system, action):
         self.model.select(system, action)
-        self.app.next_screen()
+        self.app.request_next_screen()
 
     def more_options(self):
         self._current_view = self._all_view
@@ -96,4 +96,4 @@ class RecoveryChooserConfirmController(RecoveryChooserBaseController):
 
     def back(self):
         self.model.unselect()
-        self.app.prev_screen()
+        self.app.request_prev_screen()

console_conf/controllers/tests/test_chooser.py

@@ -74,7 +74,7 @@ class TestChooserConfirmController(unittest.TestCase):
         c.back()
         app.respond.assert_not_called()
         app.exit.assert_not_called()
-        app.prev_screen.assert_called()
+        app.request_prev_screen.assert_called()
         c.model.unselect.assert_called()
 
     def test_confirm(self):
@@ -106,7 +106,7 @@ class TestChooserController(unittest.TestCase):
         )
         self.assertEqual(c.model.selection, exp)
 
-        app.next_screen.assert_called()
+        app.request_next_screen.assert_called()
         app.respond.assert_not_called()
         app.exit.assert_not_called()
 

console_conf/controllers/welcome.py

@@ -24,7 +24,7 @@ class WelcomeController(TuiController):
         return self.welcome_view(self)
 
     def done(self):
-        self.app.next_screen()
+        self.app.request_next_screen()
 
     def cancel(self):
         # Can't go back from here!

subiquity/client/client.py

@@ -483,7 +483,7 @@ class SubiquityClient(TuiApplication):
         self._remove_last_screen()
         super().exit()
 
-    def select_initial_screen(self):
+    async def select_initial_screen(self):
         last_screen = None
         if self.updated:
             state_path = self.state_path("last-screen")
@@ -495,7 +495,7 @@ class SubiquityClient(TuiApplication):
             for i, controller in enumerate(self.controllers.instances):
                 if controller.name == last_screen:
                     index = i
-        run_bg_task(self._select_initial_screen(index))
+        await self._select_initial_screen(index)
 
     async def _select_initial_screen(self, index):
         endpoint_names = []
@@ -507,7 +507,7 @@ class SubiquityClient(TuiApplication):
         if self.variant:
             await self.client.meta.client_variant.POST(self.variant)
         self.controllers.index = index - 1
-        self.next_screen()
+        await self.next_screen()
 
     async def move_screen(self, increment, coro):
         try:

subiquity/client/controllers/drivers.py

@@ -62,8 +62,10 @@ class DriversController(SubiquityTuiController):
         click(view.form.done_btn.base_widget)
 
     def cancel(self) -> None:
-        self.app.prev_screen()
+        self.app.request_prev_screen()
 
     def done(self, install: bool) -> None:
         log.debug("DriversController.done next_screen install=%s", install)
-        self.app.next_screen(self.endpoint.POST(DriversPayload(install=install)))
+        self.app.request_next_screen(
+            self.endpoint.POST(DriversPayload(install=install))
+        )

subiquity/client/controllers/filesystem.py

@@ -260,7 +260,7 @@ class FilesystemController(SubiquityTuiController, FilesystemManipulator):
     async def _guided_choice(self, choice: GuidedChoiceV2):
         coro = self.endpoint.guided.POST(choice)
         if not choice.capability.supports_manual_customization():
-            self.app.next_screen(coro)
+            await self.app.next_screen(coro)
             return
         status = await self.app.wait_with_progress(coro)
         self.model = FilesystemModel(status.bootloader, root="/")
@@ -294,11 +294,11 @@ class FilesystemController(SubiquityTuiController, FilesystemManipulator):
             self.ui.set_body(FilesystemView(self.model, self))
 
     def cancel(self):
-        self.app.prev_screen()
+        self.app.request_prev_screen()
 
     def finish(self):
         log.debug("FilesystemController.finish next_screen")
-        self.app.next_screen(
+        self.app.request_next_screen(
             self.endpoint.POST(
                 self.model._render_actions(mode=ActionRenderMode.FOR_API_CLIENT)
             )

subiquity/client/controllers/identity.py

@@ -43,11 +43,11 @@ class IdentityController(SubiquityTuiController):
             self.done(identity)
 
     def cancel(self):
-        self.app.prev_screen()
+        self.app.request_prev_screen()
 
     def done(self, identity_data):
         log.debug("IdentityController.done next_screen user_spec=%s", identity_data)
-        self.app.next_screen(self.endpoint.POST(identity_data))
+        self.app.request_next_screen(self.endpoint.POST(identity_data))
 
     async def validate_username(self, username):
         return await self.endpoint.validate_username.GET(username)

subiquity/client/controllers/keyboard.py

@@ -49,7 +49,7 @@ class KeyboardController(SubiquityTuiController):
         await self.endpoint.POST(setting)
 
     def done(self):
-        self.app.next_screen()
+        self.app.request_next_screen()
 
     def cancel(self):
-        self.app.prev_screen()
+        self.app.request_prev_screen()

subiquity/client/controllers/mirror.py

@@ -67,8 +67,8 @@ class MirrorController(SubiquityTuiController):
             self.app.ui.body.form._click_done(None)
 
     def cancel(self):
-        self.app.prev_screen()
+        self.app.request_prev_screen()
 
     def done(self, mirror):
         log.debug("MirrorController.done next_screen mirror=%s", mirror)
-        self.app.next_screen(self.endpoint.POST(MirrorPost(elected=mirror)))
+        self.app.request_next_screen(self.endpoint.POST(MirrorPost(elected=mirror)))

subiquity/client/controllers/network.py

@@ -118,10 +118,10 @@ class NetworkController(SubiquityTuiController, NetworkAnswersMixin):
             run_bg_task(self.unsubscribe())
 
     def cancel(self):
-        self.app.prev_screen()
+        self.app.request_prev_screen()
 
     def done(self):
-        self.app.next_screen(self.endpoint.POST())
+        self.app.request_next_screen(self.endpoint.POST())
 
     def set_static_config(
         self, dev_name: str, ip_version: int, static_config: StaticConfig

subiquity/client/controllers/proxy.py

@@ -33,8 +33,8 @@ class ProxyController(SubiquityTuiController):
             self.done(self.answers["proxy"])
 
     def cancel(self):
-        self.app.prev_screen()
+        self.app.request_prev_screen()
 
     def done(self, proxy):
         log.debug("ProxyController.done next_screen proxy=%s", proxy)
-        self.app.next_screen(self.endpoint.POST(proxy))
+        self.app.request_next_screen(self.endpoint.POST(proxy))

subiquity/client/controllers/refresh.py

@@ -77,7 +77,7 @@ class RefreshController(SubiquityTuiController):
 
     def done(self, sender=None):
         log.debug("RefreshController.done next_screen")
-        self.app.next_screen()
+        self.app.request_next_screen()
 
     def cancel(self, sender=None):
-        self.app.prev_screen()
+        self.app.request_prev_screen()

subiquity/client/controllers/serial.py

@@ -39,7 +39,7 @@ class SerialController(SubiquityTuiController):
     def done(self, rich):
         log.debug("SerialController.done rich %s next_screen", rich)
         self.app.set_rich(rich)
-        self.app.next_screen()
+        self.app.request_next_screen()
 
     def cancel(self):
         # Can't go back from here!

subiquity/client/controllers/snaplist.py

@@ -47,10 +47,10 @@ class SnapListController(SubiquityTuiController):
 
     def done(self, selections: List[SnapSelection]):
         log.debug("SnapListController.done next_screen snaps_to_install=%s", selections)
-        self.app.next_screen(self.endpoint.POST(selections))
+        self.app.request_next_screen(self.endpoint.POST(selections))
 
     def cancel(self, sender=None):
-        self.app.prev_screen()
+        self.app.request_prev_screen()
 
     async def get_list_wait(self):
         return await self.endpoint.GET(wait=True)

subiquity/client/controllers/source.py

@@ -43,7 +43,7 @@ class SourceController(SubiquityTuiController):
             form._click_done(None)
 
     def cancel(self):
-        self.app.prev_screen()
+        self.app.request_prev_screen()
 
     def done(self, source_id, search_drivers: bool):
         log.debug(
@@ -51,4 +51,4 @@ class SourceController(SubiquityTuiController):
             source_id,
             search_drivers,
         )
-        self.app.next_screen(self.endpoint.POST(source_id, search_drivers))
+        self.app.request_next_screen(self.endpoint.POST(source_id, search_drivers))

subiquity/client/controllers/ssh.py

@@ -84,7 +84,7 @@ class SSHController(SubiquityTuiController):
         form._click_done(None)
 
     def cancel(self):
-        self.app.prev_screen()
+        self.app.request_prev_screen()
 
     def _fetch_cancel(self):
         if self._fetch_task is None:
@@ -123,4 +123,4 @@ class SSHController(SubiquityTuiController):
 
     def done(self, result):
         log.debug("SSHController.done next_screen result=%s", result)
-        self.app.next_screen(self.endpoint.POST(result))
+        self.app.request_next_screen(self.endpoint.POST(result))

subiquity/client/controllers/ubuntu_pro.py

@@ -216,13 +216,13 @@ class UbuntuProController(SubiquityTuiController):
             schedule_task(inner())
 
     def cancel(self) -> None:
-        self.app.prev_screen()
+        self.app.request_prev_screen()
 
     def done(self, token: str) -> None:
         """Submit the token and move on to the next screen."""
-        self.app.next_screen(self.endpoint.POST(UbuntuProInfo(token=token)))
+        self.app.request_next_screen(self.endpoint.POST(UbuntuProInfo(token=token)))
 
     def next_screen(self) -> None:
         """Move on to the next screen. Assume the token should not be
         submitted (or has already been submitted)."""
-        self.app.next_screen()
+        self.app.request_next_screen()

subiquity/client/controllers/welcome.py

@@ -48,10 +48,10 @@ class WelcomeController(SubiquityTuiController):
         log.debug("WelcomeController.done %s next_screen", code)
         i18n.switch_language(code)
         self.app.native_language = display_name
-        self.app.next_screen(self.endpoint.POST(code))
+        self.app.request_next_screen(self.endpoint.POST(code))
 
     def cancel(self, sender=None):
         if not self.serial:
             # Can't go back from here unless we're on serial!
             pass
-        self.app.prev_screen()
+        self.app.request_prev_screen()

subiquity/client/controllers/zdev.py

@@ -33,11 +33,11 @@ class ZdevController(SubiquityTuiController):
             self.done()
 
     def cancel(self):
-        self.app.prev_screen()
+        self.app.request_prev_screen()
 
     def done(self):
         # switch to next screen
-        self.app.next_screen()
+        self.app.request_next_screen()
 
     async def chzdev(self, action, zdevinfo):
         return await self.endpoint.chzdev.POST(action, zdevinfo)

subiquity/ui/views/installprogress.py

@@ -296,7 +296,7 @@ class InstallConfirmation(Stretchy):
         if self.app.controllers.Progress.showing:
             run_bg_task(self.app.confirm_install())
         else:
-            self.app.next_screen(self.app.confirm_install())
+            self.app.request_next_screen(self.app.confirm_install())
 
     def cancel(self, sender):
         self.app.remove_global_overlay(self)

subiquitycore/controllers/network.py

@@ -663,7 +663,7 @@ class NetworkController(BaseNetworkController, TuiController, NetworkAnswersMixi
     def done(self):
         log.debug("NetworkController.done next_screen")
         self.model.has_network = self.network_event_receiver.has_default_route
-        self.app.next_screen()
+        self.app.request_next_screen()
 
     def cancel(self):
         self.app.prev_screen()

subiquitycore/tests/mocks.py

@@ -41,8 +41,8 @@ def make_app(model=None):
     app.context = Context.new(app)
     app.exit = mock.Mock()
     app.respond = mock.Mock()
-    app.next_screen = mock.Mock()
-    app.prev_screen = mock.Mock()
+    app.request_next_screen = mock.Mock()
+    app.request_prev_screen = mock.Mock()
     app.hub = MessageHub()
     app.opts = mock.Mock()
     app.opts.dry_run = True

subiquitycore/tui.py

@@ -156,7 +156,7 @@ class TuiApplication(Application):
             self.ui.block_input = False
             nonlocal min_show_task
             min_show_task = asyncio.create_task(asyncio.sleep(MIN_SHOW_PROGRESS_TIME))
-            show()
+            await show()
 
         self.ui.block_input = True
         show_task = asyncio.create_task(_show())
@@ -166,7 +166,7 @@ class TuiApplication(Application):
             if min_show_task:
                 await min_show_task
                 if hide is not None:
-                    hide()
+                    await hide()
             else:
                 self.ui.block_input = False
                 show_task.cancel()
@@ -191,18 +191,24 @@ class TuiApplication(Application):
             else:
                 task_to_cancel = None
 
-        def show_load():
+        async def show_load():
             nonlocal ld
             ld = LoadingDialog(self.ui.body, message, task_to_cancel)
             self.ui.body.show_overlay(ld, width=ld.width)
+            await self.redraw_screen()
 
-        def hide_load():
+        async def hide_load():
             ld.close()
+            await self.redraw_screen()
 
         return await self._wait_with_indication(awaitable, show_load, hide_load)
 
     async def wait_with_progress(self, awaitable):
-        return await self._wait_with_indication(awaitable, self.show_progress)
+        async def show_progress():
+            self.show_progress()
+            await self.redraw_screen()
+
+        return await self._wait_with_indication(awaitable, show_progress)
 
     async def _move_screen(
         self, increment, coro
@@ -243,14 +249,36 @@ class TuiApplication(Application):
                 view = view_or_callable
             self.ui.set_body(view)
 
-    def next_screen(self, coro=None):
-        run_bg_task(self.move_screen(1, coro))
+    async def redraw_screen(self):
+        self.urwid_loop.draw_screen()
 
-    def prev_screen(self):
-        run_bg_task(self.move_screen(-1, None))
+    async def next_screen(self, coro=None):
+        await self.move_screen(1, coro)
 
-    def select_initial_screen(self):
-        self.next_screen()
+    async def prev_screen(self):
+        await self.move_screen(-1, None)
+
+    async def select_initial_screen(self):
+        await self.next_screen()
+
+    def request_next_screen(self, coro=None, *, redraw=True):
+        async def next_screen():
+            await self.next_screen(coro)
+            if redraw:
+                await self.redraw_screen()
+
+        run_bg_task(next_screen())
+
+    def request_prev_screen(self, *, redraw=True):
+        async def prev_screen():
+            await self.prev_screen()
+            if redraw:
+                await self.redraw_screen()
+
+        run_bg_task(prev_screen())
+
+    def request_screen_redraw(self):
+        run_bg_task(self.redraw_screen())
 
     def set_rich(self, rich):
         if rich == self.rich_mode:
@@ -321,7 +349,7 @@ class TuiApplication(Application):
         # By default, basic on serial - rich otherwise.
         return not self.opts.run_on_serial
 
-    def start_urwid(self, input=None, output=None):
+    async def start_urwid(self, input=None, output=None):
         # This stops the tcsetpgrp call in run_command_in_foreground from
         # suspending us. See the rant there for more details.
         signal.signal(signal.SIGTTOU, signal.SIG_IGN)
@@ -339,12 +367,13 @@ class TuiApplication(Application):
         extend_dec_special_charmap()
         self.set_rich(self.get_initial_rich_mode())
         self.urwid_loop.start()
-        self.select_initial_screen()
+        await self.select_initial_screen()
+        await self.redraw_screen()
 
     async def start(self, start_urwid=True):
         await super().start()
         if start_urwid:
-            self.start_urwid()
+            await self.start_urwid()
 
     async def run(self):
         try:

system_setup/client/controllers/wslconfadvanced.py

@@ -47,7 +47,7 @@ class WSLConfigurationAdvancedController(SubiquityTuiController):
             "WSLConfigurationAdvancedController.done next_screen user_spec=%s",
             reconf_data,
         )
-        self.app.next_screen(self.endpoint.POST(reconf_data))
+        self.app.request_next_screen(self.endpoint.POST(reconf_data))
 
     def cancel(self):
-        self.app.prev_screen()
+        self.app.request_prev_screen()

system_setup/client/controllers/wslconfbase.py

@@ -32,7 +32,7 @@ class WSLConfigurationBaseController(SubiquityTuiController):
             "WSLConfigurationBaseController.done next_screen user_spec=%s",
             configuration_data,
         )
-        self.app.next_screen(self.endpoint.POST(configuration_data))
+        self.app.request_next_screen(self.endpoint.POST(configuration_data))
 
     def cancel(self):
-        self.app.prev_screen()
+        self.app.request_prev_screen()

system_setup/client/controllers/wslsetupoptions.py

@@ -41,7 +41,7 @@ class WSLSetupOptionsController(SubiquityTuiController):
             "WSLSetupOptionsController.done next_screen user_spec=%s",
             configuration_data,
         )
-        self.app.next_screen(self.endpoint.POST(configuration_data))
+        self.app.request_next_screen(self.endpoint.POST(configuration_data))
 
     def cancel(self):
-        self.app.prev_screen()
+        self.app.request_prev_screen()