fix(core): properly send the resume signal to homescreen layouts

core/src/trezor/ui/__init__.py

@@ -8,12 +8,12 @@ import trezorui2
 from trezor import io, log, loop, utils, wire, workflow
 from trezor.messages import ButtonAck, ButtonRequest
 from trezor.wire import context
-from trezorui2 import BacklightLevels, LayoutState
+from trezorui2 import AttachType, BacklightLevels, LayoutState
 
 if TYPE_CHECKING:
     from typing import Any, Callable, Generator, Generic, Iterator, TypeVar
 
-    from trezorui2 import AttachType, LayoutObj, UiResult  # noqa: F401
+    from trezorui2 import LayoutObj, UiResult  # noqa: F401
 
     T = TypeVar("T", covariant=True)
 
@@ -169,6 +169,10 @@ class Layout(Generic[T]):
         self.context: context.Context | None = None
         self.state: LayoutState = LayoutState.INITIAL
 
+        # Indicates whether we should use Resume attach style when launching.
+        # Homescreen layouts can override this.
+        self.should_resume = False
+
     def is_ready(self) -> bool:
         """True if the layout is in READY state."""
         return CURRENT_LAYOUT is not self and self.result_box.is_empty()
@@ -198,7 +202,7 @@ class Layout(Generic[T]):
         # make sure we are not restarted before picking the previous result
         assert self.is_ready()
 
-        transition_in = None
+        transition_in = AttachType.RESUME if self.should_resume else AttachType.INITIAL
 
         # set up the global layout, shutting down any competitors
         # (caller should still call `workflow.close_others()` to ensure that someone

core/src/trezor/ui/layouts/common.py

@@ -1,7 +1,7 @@
 from typing import TYPE_CHECKING
 
 import trezorui2
-from trezor import ui, utils, workflow
+from trezor import ui, workflow
 from trezor.enums import ButtonRequestType
 from trezor.messages import ButtonAck, ButtonRequest
 from trezor.wire import ActionCancelled, context
@@ -109,14 +109,4 @@ async def with_info(
 
 
 def draw_simple(layout: trezorui2.LayoutObj[Any]) -> None:
-    # Simple drawing not supported for layouts that set timers.
-    def dummy_set_timer(token: int, duration: int) -> None:
-        raise RuntimeError
-
-    layout.attach_timer_fn(dummy_set_timer, None)
-    if utils.USE_BACKLIGHT:
-        ui.backlight_fade(ui.BacklightLevels.DIM)
-    if layout.paint():
-        ui.refresh()
-    if utils.USE_BACKLIGHT:
-        ui.backlight_fade(ui.BacklightLevels.NORMAL)
+    ui.Layout(layout).start()

core/src/trezor/ui/layouts/homescreen.py

@@ -15,13 +15,17 @@ class HomescreenBase(ui.Layout):
 
     def __init__(self, layout: Any) -> None:
         super().__init__(layout=layout)
+        self.should_resume = self._should_resume()
+
+    def _should_resume(self) -> bool:
+        return storage_cache.homescreen_shown is self.RENDER_INDICATOR
 
     def _paint(self) -> None:
         if self.layout.paint():
             ui.refresh()
 
     def _first_paint(self) -> None:
-        if storage_cache.homescreen_shown is not self.RENDER_INDICATOR:
+        if not self.should_resume:
             super()._first_paint()
             storage_cache.homescreen_shown = self.RENDER_INDICATOR
         # else:
@@ -50,15 +54,14 @@ class Homescreen(HomescreenBase):
             elif notification_is_error:
                 level = 0
 
-        skip = storage_cache.homescreen_shown is self.RENDER_INDICATOR
         super().__init__(
             layout=trezorui2.show_homescreen(
                 label=label,
                 notification=notification,
                 notification_level=level,
                 hold=hold_to_lock,
-                skip_first_paint=skip,
-            ),
+                skip_first_paint=self._should_resume(),
+            )
         )
 
     async def usb_checker_task(self) -> None:
@@ -99,6 +102,7 @@ class Lockscreen(HomescreenBase):
                 coinjoin_authorized=coinjoin_authorized,
             ),
         )
+        self.should_resume = skip
 
     async def get_result(self) -> Any:
         result = await super().get_result()
@@ -111,13 +115,12 @@ class Busyscreen(HomescreenBase):
     RENDER_INDICATOR = storage_cache.BUSYSCREEN_ON
 
     def __init__(self, delay_ms: int) -> None:
-        skip = storage_cache.homescreen_shown is self.RENDER_INDICATOR
         super().__init__(
             layout=trezorui2.show_progress_coinjoin(
                 title=TR.coinjoin__waiting_for_others,
                 indeterminate=True,
                 time_ms=delay_ms,
-                skip_first_paint=skip,
+                skip_first_paint=self._should_resume(),
             )
         )