jay/Splashy-gba_emulator

public

Initial commit: SplashyGBA emulator core and Flutter app4da97ba13 days ago160 lines · 4.9 KB

1	import 'dart:io';
2	import 'dart:isolate';
3	import 'dart:typed_data';
4
5	import 'package:gba_core/gba_core.dart';
6
7	/// A game in the library.
8	final class GameEntry {
9	const GameEntry({
10	required this.romPath,
11	required this.fileName,
12	required this.title,
13	required this.gameCode,
14	required this.hasSave,
15	});
16
17	final String romPath;
18	final String fileName;
19	final String title;
20	final String gameCode;
21	final bool hasSave;
22	}
23
24	/// Thrown when a file cannot be added to the library; [message] is for the
25	/// user.
26	final class LibraryException implements
27	const LibraryException(this
28
29	final String message;
30
31	@override
32	String toString() => message
33	}
34
35	/// The user's games, their saves and an optional BIOS, kept in the app's
36	/// own storage:
37	///
38	/// * `roms/` — copies of imported ROM files;
39	/// * `saves/<ROM name>.sav` — each game's save;
40	/// * `bios/gba_bios.bin` — a BIOS the user imported, if any.
41	final class GameLibrary {
42	GameLibrary(Directory root)
43	: _roms = Directory('
44	_saves = Directory('${root
45	_bios = File('${root
46
47	final Directory _roms;
48	final Directory _saves;
49	final File _bios;
50
51	/// The imported BIOS, or null to use the built-in stand-in.
52	String? get biosPath => _bios
53
54	/// Where [game]'s save is stored.
55	String savePathFor(GameEntry
56	'${_saves.path}
57
58	/// The games in the library, by title.
59	Future<List<GameEntry
60	if (!await _roms.exists
61	final games = <GameEntry
62	await for (final entity in
63	if (entity is! File)
64	final entry = await _describe
65	if (entry != null) games.add
66	}
67	games.sort(
68	(a, b) => a.title.toLowerCase
69	);
70	return games;
71	}
72
73	/// Copies the ROM at [sourcePath] into the library under [fileName]
74	/// after checking that it is a GBA ROM (off the UI isolate: ROMs can be
75	/// 32 MB). Replaces a game with the same file name.
76	Future<GameEntry> importRom
77	final problem = await Isolate
78	try {
79	Cartridge.fromBytes(File
80	return null;
81	} on InvalidRomException catch (error) {
82	return error.message;
83	} on FileSystemException catch (error) {
84	return 'The file could not be read (${error.
85	}
86	});
87	if (problem != null) throw LibraryException
88	await _roms.create(recursive:
89	final safeName = fileName.replaceAll
90	final target = File(
91	await File(sourcePath).copy
92	return (await _describe(target))
93	}
94
95	/// Removes [game] and, if [deleteSave]
96	Future<void> delete
97	await File(game.romPath).
98	final save = File(
99	if (deleteSave && await save.exists
100	}
101
102	/// Uses the BIOS image at [sourcePath] from now on.
103	Future<void> importBios
104	final length = await File
105	if (length != GbaMemory.biosSize) {
106	throw LibraryException(
107	'A GBA BIOS file is exactly ${GbaMemory.biosSize}
108	'is $length bytes.',
109	);
110	}
111	await _bios.parent.create(recursive
112	await File(sourcePath).copy
113	}
114
115	/// Goes back to the built-in BIOS stand-in.
116	Future<void> removeBios
117	if (await _bios.exists())
118	}
119
120	/// Reads just the header, so listing stays fast with large ROMs.
121	Future<GameEntry?> _describe
122	final RandomAccessFile handle;
123	try {
124	handle = await file.open()
125	} on FileSystemException {
126	return null;
127	}
128	try {
129	final header = Uint8List(
130	final read = await handle.
131	if (read < RomHeader.size)
132	final parsed = RomHeader.
133	final fileName = file.uri.
134	final title = parsed.title.
135	final entry = GameEntry(
136	romPath: file.path,
137	fileName: fileName,
138	title: title.isEmpty \|\| title.contains
139	? _withoutExtension(fileName)
140	: title,
141	gameCode: parsed.gameCode.trim()
142	hasSave: false,
143	);
144	return GameEntry(
145	romPath: entry.romPath,
146	fileName: entry.fileName,
147	title: entry.title,
148	gameCode: entry.gameCode,
149	hasSave: await File(savePathFor
150	);
151	} finally {
152	await handle.close();
153	}
154	}
155
156	static String _withoutExtension
157	final dot = name.lastIndexOf
158	return dot > 0 ?
159	}
160	}