feat: configure minimum splash duration

src/ccma/ui/splash.py

@@ -1,6 +1,8 @@
 from __future__ import annotations
 
+import math
 import threading
+import time
 import tkinter as tk
 from collections.abc import Callable
 from dataclasses import dataclass
@@ -33,6 +35,7 @@ class SplashScreen(tk.Toplevel):
         run_housekeeper: bool = True,
         monitor: MonitorBounds | None = None,
         housekeeper_settings: HousekeeperSettings | None = None,
+        minimum_display_seconds: float = 5.0,
     ):
         super().__init__(master)
         self.repository = repository
@@ -41,6 +44,10 @@ class SplashScreen(tk.Toplevel):
         self.run_housekeeper = run_housekeeper
         self.monitor = monitor
         self.housekeeper_settings = housekeeper_settings
+        self.minimum_display_seconds = (
+            max(0.0, float(minimum_display_seconds)) if math.isfinite(float(minimum_display_seconds)) else 5.0
+        )
+        self.shown_at = time.monotonic()
         self._messages: Queue[tuple[str, object]] = Queue()
         self.overrideredirect(True)
         self.resizable(False, False)
@@ -145,7 +152,15 @@ class SplashScreen(tk.Toplevel):
     def _finish(self, result: StartupResult) -> None:
         self.progress.stop()
         self._set_status(f"Bereit · {len(result.findings)} Vorgänge benötigen Aufmerksamkeit")
-        self.after(350, lambda: self._complete(result))
+        self._after_minimum(lambda: self._complete(result))
+
+    def _after_minimum(self, callback: Callable[[], None]) -> None:
+        remaining_ms = _remaining_minimum_ms(
+            self.shown_at,
+            self.minimum_display_seconds,
+            time.monotonic(),
+        )
+        self.after(remaining_ms, callback)
 
     def _set_status(self, text: str) -> None:
         self.canvas.itemconfigure(self.status_item, text=text)
@@ -156,6 +171,10 @@ class SplashScreen(tk.Toplevel):
 
     def _fail(self, error: Exception) -> None:
         self.progress.stop()
+        self._set_status("Start fehlgeschlagen")
+        self._after_minimum(lambda: self._complete_error(error))
+
+    def _complete_error(self, error: Exception) -> None:
         self.destroy()
         self.on_error(error)
 
@@ -177,3 +196,8 @@ def centered_position(
     x = min(max(pointer_x - width // 2, screen_x), maximum_x)
     y = min(max(pointer_y - height // 2, screen_y), maximum_y)
     return x, y
+
+
+def _remaining_minimum_ms(started_at: float, minimum_seconds: float, now: float) -> int:
+    remaining = max(0.0, minimum_seconds - max(0.0, now - started_at))
+    return int(remaining * 1000 + 0.999)