[gui] remember window size + better default sizes

src/client/gui/lib/main.dart

@@ -4,7 +4,6 @@ import 'package:hotkey_manager/hotkey_manager.dart';
 import 'package:local_notifier/local_notifier.dart';
 import 'package:shared_preferences/shared_preferences.dart';
 import 'package:window_manager/window_manager.dart';
-import 'package:window_size/window_size.dart';
 
 import 'before_quit_dialog.dart';
 import 'catalogue/catalogue.dart';
@@ -20,6 +19,7 @@ import 'tray_menu.dart';
 import 'vm_details/mapping_slider.dart';
 import 'vm_details/vm_details.dart';
 import 'vm_table/vm_table_screen.dart';
+import 'window_size.dart';
 
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
@@ -31,25 +31,12 @@ void main() async {
     shortcutPolicy: ShortcutPolicy.requireCreate, // Only for Windows
   );
 
-  // Get the current screen size
-  final screenSize = await getCurrentScreen().then((screen) {
-    return screen?.frame.size;
-  });
-
-  final windowSize = (screenSize != null)
-    ? (screenSize.width >= 1600 && screenSize.height >= 900)
-      ? const Size(1400, 822) // For screens 1600x900 or larger
-      : (screenSize.width >= 1280 && screenSize.height >= 720)
-        ? const Size(1024, 576) // For screens 1280x720 or larger
-        : const Size(750, 450) // Default window size
-    : const Size(750, 450); // Default window size if screenSize is null
-
+  final sharedPreferences = await SharedPreferences.getInstance();
   await windowManager.ensureInitialized();
-
   final windowOptions = WindowOptions(
     center: true,
     minimumSize: const Size(750, 450),
-    size: windowSize,
+    size: await deriveWindowSize(sharedPreferences),
     title: 'Multipass',
   );
 
@@ -59,7 +46,6 @@ void main() async {
   });
 
   await hotKeyManager.unregisterAll();
-  final sharedPreferences = await SharedPreferences.getInstance();
 
   providerContainer = ProviderContainer(overrides: [
     guiSettingProvider.overrideWith(() {
@@ -169,6 +155,11 @@ class _AppState extends ConsumerState<App> with WindowListener {
     super.dispose();
   }
 
+  // this event handler is called continuously during a window resizing operation
+  // so we want to save the data to the disk only after the resizing stops
+  @override
+  void onWindowResize() => saveWindowSizeTimer.reset();
+
   @override
   void onWindowClose() async {
     if (!await windowManager.isPreventClose()) return;

src/client/gui/lib/window_size.dart

@@ -0,0 +1,96 @@
+import 'dart:ui';
+
+import 'package:async/async.dart';
+import 'package:basics/basics.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+import 'package:window_manager/window_manager.dart';
+import 'package:window_size/window_size.dart';
+
+import 'logger.dart';
+
+const windowWidthKey = 'windowWidth';
+const windowHeightKey = 'windowHeight';
+
+String resolutionString(Size? size) {
+  return size != null ? '${size.width}x${size.height}' : '';
+}
+
+final saveWindowSizeTimer = RestartableTimer(1.seconds, () async {
+  final currentSize = await windowManager.getSize();
+  final sharedPreferences = await SharedPreferences.getInstance();
+  final screenSize = await getCurrentScreenSize();
+  logger.d(
+    'Saving window size ${currentSize.s()} for screen size ${screenSize?.s()}',
+  );
+  final prefix = resolutionString(screenSize);
+  sharedPreferences.setDouble('$prefix$windowWidthKey', currentSize.width);
+  sharedPreferences.setDouble('$prefix$windowHeightKey', currentSize.height);
+});
+
+Future<Size?> getCurrentScreenSize() async {
+  try {
+    final screen = await getCurrentScreen();
+    if (screen == null) throw Exception('Screen instance is null');
+
+    logger.d(
+      'Got Screen{frame: ${screen.frame.s()}, scaleFactor: ${screen.scaleFactor}, visibleFrame: ${screen.visibleFrame.s()}}',
+    );
+
+    return screen.visibleFrame.size;
+  } catch (e) {
+    logger.w('Failed to get current screen information: $e');
+    return null;
+  }
+}
+
+Future<Size> deriveWindowSize(SharedPreferences sharedPreferences) async {
+  final screenSize = await getCurrentScreenSize();
+  final prefix = resolutionString(screenSize);
+  final lastWidth = sharedPreferences.getDouble('$prefix$windowWidthKey');
+  final lastHeight = sharedPreferences.getDouble('$prefix$windowHeightKey');
+  final size = lastWidth != null && lastHeight != null
+      ? Size(lastWidth, lastHeight)
+      : null;
+  logger.d('Got last window size: ${size?.s()}');
+  return size ?? computeDefaultWindowSize(screenSize);
+}
+
+Size computeDefaultWindowSize(Size? screenSize) {
+  const windowSizeFactor = 0.8;
+  final (screenWidth, screenHeight) = (screenSize?.width, screenSize?.height);
+  final aspectRatioFactor = screenSize?.flipped.aspectRatio;
+
+  final defaultWidth = switch (screenWidth) {
+    null || <= 1024 => 750.0,
+    >= 1600 => 1400.0,
+    _ => screenWidth * windowSizeFactor,
+  };
+
+  final defaultHeight = switch (screenHeight) {
+    null || <= 576 => 450.0,
+    >= 900 => 822.0,
+    _ => aspectRatioFactor != null
+        ? defaultWidth * aspectRatioFactor
+        : screenHeight * windowSizeFactor,
+  };
+
+  final size = Size(defaultWidth, defaultHeight);
+  logger.d('Computed default window size: ${size.s()}');
+  return size;
+}
+
+// needed because in release mode Flutter does not emit the actual code for toString for some classes
+// instead the returned strings are of type "Instance of '<Type>'"
+// this is done to reduce binary size, and it cannot be turned off :face-with-rolling-eyes:
+// see https://api.flutter.dev/flutter/dart-ui/keepToString-constant.html for more info
+extension on Size {
+  String s() {
+    return 'Size(${width.toStringAsFixed(1)}, ${height.toStringAsFixed(1)})';
+  }
+}
+
+extension on Rect {
+  String s() {
+    return 'Rect.fromLTRB(${left.toStringAsFixed(1)}, ${top.toStringAsFixed(1)}, ${right.toStringAsFixed(1)}, ${bottom.toStringAsFixed(1)})';
+  }
+}