Automatic save/restore

iOS/GBROMManager.h

@@ -5,5 +5,15 @@
 
 @property (readonly) NSArray<NSString *> *allROMs;
 @property (nonatomic) NSString *currentROM;
+
 @property (readonly) NSString *romFile;
+@property (readonly) NSString *batterySaveFile;
+@property (readonly) NSString *autosaveStateFile;
+- (NSString *)stateFile:(unsigned)index;
+
+- (NSString *)romFileForROM:(NSString *)rom;
+- (NSString *)batterySaveFileForROM:(NSString *)rom;
+- (NSString *)autosaveStateFileForROM:(NSString *)rom;
+- (NSString *)stateFile:(unsigned)index forROM:(NSString *)rom;
+
 @end

iOS/GBROMManager.m

@@ -54,6 +54,51 @@
     return _romFile = [self romFileForDirectory:romDirectory];
 }
 
+- (NSString *)romFileForROM:(NSString *)rom
+{
+    if (rom == _currentROM) {
+        return self.romFile;
+    }
+    NSString *root = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, true).firstObject;
+    NSString *romDirectory = [root stringByAppendingPathComponent:_currentROM];
+    return [self romFileForDirectory:romDirectory];
+}
+
+- (NSString *)auxilaryFileForROM:(NSString *)rom withExtension:(NSString *)extension
+{
+    return [[[self romFileForROM:rom] stringByDeletingPathExtension] stringByAppendingPathExtension:extension];
+}
+
+- (NSString *)batterySaveFileForROM:(NSString *)rom
+{
+    return [self auxilaryFileForROM:rom withExtension:@"sav"];
+}
+
+- (NSString *)batterySaveFile
+{
+    return [self batterySaveFileForROM:_currentROM];
+}
+
+- (NSString *)autosaveStateFileForROM:(NSString *)rom
+{
+    return [self auxilaryFileForROM:rom withExtension:@"auto"];
+}
+
+- (NSString *)autosaveStateFile
+{
+    return [self autosaveStateFileForROM:_currentROM];
+}
+
+- (NSString *)stateFile:(unsigned)index forROM:(NSString *)rom
+{
+    return [self auxilaryFileForROM:rom withExtension:[NSString stringWithFormat:@"s%u", index]];
+}
+
+- (NSString *)stateFile:(unsigned)index
+{
+    return [self stateFile:index forROM:_currentROM];
+}
+
 - (NSArray<NSString *> *)allROMs
 {
     NSMutableArray<NSString *> *ret = [NSMutableArray array];

iOS/GBViewController.m

@@ -130,6 +130,10 @@ static void rumbleCallback(GB_gameboy_t *gb, double amp)
     if (romManager.romFile) {
         // Todo: display errors and warnings
         _romLoaded = GB_load_rom(&_gb, romManager.romFile.fileSystemRepresentation) == 0;
+        if (_romLoaded) {
+            GB_load_battery(&_gb, [GBROMManager sharedManager].batterySaveFile.fileSystemRepresentation);
+            GB_load_state(&_gb, [GBROMManager sharedManager].autosaveStateFile.fileSystemRepresentation);
+        }
     }
 }
 
@@ -238,8 +242,8 @@ static void rumbleCallback(GB_gameboy_t *gb, double amp)
     [_audioClient stop];
     _audioClient = nil;
 
-    // Todo
-    //GB_save_battery(&gb, self.savPath.UTF8String);
+    GB_save_battery(&_gb, [GBROMManager sharedManager].batterySaveFile.fileSystemRepresentation);
+    GB_save_state(&_gb, [GBROMManager sharedManager].autosaveStateFile.fileSystemRepresentation);
 }
 
 - (void)start