Fix Linux startup theme flash (#195)

src-tauri/capabilities/default.json

@@ -11,6 +11,7 @@
     "core:window:allow-minimize",
     "core:window:allow-toggle-maximize",
     "core:window:allow-close",
+    "core:window:allow-show",
     "core:window:allow-is-maximized",
     "core:window:allow-set-decorations",
     "core:window:allow-is-fullscreen",

src-tauri/src/lib.rs

@@ -313,7 +313,16 @@ pub fn run() {
         }));
 
         builder = builder.plugin(tauri_plugin_updater::Builder::new().build());
-        builder = builder.plugin(tauri_plugin_window_state::Builder::default().build());
+        let window_state_builder = tauri_plugin_window_state::Builder::default();
+        #[cfg(target_os = "linux")]
+        let window_state_builder = window_state_builder.with_state_flags(
+            tauri_plugin_window_state::StateFlags::SIZE
+                | tauri_plugin_window_state::StateFlags::POSITION
+                | tauri_plugin_window_state::StateFlags::MAXIMIZED
+                | tauri_plugin_window_state::StateFlags::DECORATIONS
+                | tauri_plugin_window_state::StateFlags::FULLSCREEN,
+        );
+        builder = builder.plugin(window_state_builder.build());
 
         builder = builder.on_window_event(move |window, event| {
             #[cfg(target_os = "macos")]

src-tauri/tauri.linux.conf.json

@@ -0,0 +1,10 @@
+{
+  "app": {
+    "windows": [
+      {
+        "label": "main",
+        "visible": false
+      }
+    ]
+  }
+}

src/routes/+page.svelte

@@ -1,10 +1,11 @@
 <script lang="ts">
-	import { onDestroy, onMount } from 'svelte';
+	import { onDestroy, onMount, tick } from 'svelte';
 	import { appConfig, vaultReady, theme } from '$lib/stores/app';
 	import { getAppConfig, openVault, restoreExternalVault, setFontSize } from '$lib/api';
-	import { darkThemes, isIOS } from '$lib/platform';
+	import { darkThemes, isIOS, isMobile } from '$lib/platform';
 	import { getCurrentWebview } from '@tauri-apps/api/webview';
 	import { listen } from '@tauri-apps/api/event';
+	import { getCurrentWindow } from '@tauri-apps/api/window';
 	import VaultPicker from '$lib/components/VaultPicker.svelte';
 	import AppLayout from '$lib/components/AppLayout.svelte';
 	import NoteWindow from '$lib/components/NoteWindow.svelte';
@@ -15,6 +16,28 @@
 	let fontSizeSaveTimer: ReturnType<typeof setTimeout> | null = null;
 	let removeEditorZoomShortcuts: (() => void) | null = null;
 	let removeFontSizeListener: (() => void) | null = null;
+	let startupRevealTimer: ReturnType<typeof setTimeout> | null = null;
+	let startupWindowRevealed = false;
+
+	const STARTUP_REVEAL_FAILSAFE_MS = 4000;
+
+	async function revealStartupWindow() {
+		if (isMobile || startupWindowRevealed) return;
+		await tick();
+		// Force style resolution while the native window is still hidden so its first
+		// compositor frame already uses the selected theme.
+		getComputedStyle(document.body).backgroundColor;
+		try {
+			await getCurrentWindow().show();
+			startupWindowRevealed = true;
+			if (startupRevealTimer) {
+				clearTimeout(startupRevealTimer);
+				startupRevealTimer = null;
+			}
+		} catch {
+			// Plain-browser development has no Tauri window to reveal.
+		}
+	}
 
 	const defaultEditorFontSize = 14;
 	const minEditorFontSize = 10;
@@ -114,6 +137,9 @@
 	}
 
 	onMount(async () => {
+		if (!isMobile) {
+			startupRevealTimer = setTimeout(() => void revealStartupWindow(), STARTUP_REVEAL_FAILSAFE_MS);
+		}
 		// Check for note window mode
 		const params = new URLSearchParams(window.location.search);
 		const notePath = params.get('note');
@@ -209,6 +235,7 @@
 					console.error('Failed to apply interface scale:', e);
 				}
 			}
+			await revealStartupWindow();
 			removeEditorZoomShortcuts = installEditorZoomShortcuts();
 
 			// Auto-open last vault if available
@@ -242,14 +269,21 @@
 			}
 		} catch {
 			// First launch or no config
-		}
+		} finally {
 			loading = false;
+			await revealStartupWindow();
+			if (startupRevealTimer) {
+				clearTimeout(startupRevealTimer);
+				startupRevealTimer = null;
+			}
+		}
 	});
 
 	onDestroy(() => {
 		removeEditorZoomShortcuts?.();
 		removeFontSizeListener?.();
 		if (fontSizeSaveTimer) clearTimeout(fontSizeSaveTimer);
+		if (startupRevealTimer) clearTimeout(startupRevealTimer);
 	});
 </script>