Add screenshots to the ROM library (A similar functionality will be given to the state manager)

iOS/GBLoadROMTableViewController.m

@@ -1,4 +1,5 @@
 #import "GBLoadROMTableViewController.h"
+#import "GBTableViewCell.h"
 #import "GBROMManager.h"
 
 @interface GBLoadROMTableViewController ()
@@ -25,14 +26,35 @@
 
 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
 {
-    UITableViewCell *cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:nil];
+    GBTableViewCell *cell = [[GBTableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:nil];
     NSString *rom = [GBROMManager sharedManager].allROMs[[indexPath indexAtPosition:1]];
     cell.textLabel.text = rom;
     cell.accessoryType = [rom isEqualToString:[GBROMManager sharedManager].currentROM]? UITableViewCellAccessoryCheckmark : UITableViewCellAccessoryNone;
     
+    NSString *pngPath = [[[GBROMManager sharedManager] autosaveStateFileForROM:rom] stringByAppendingPathExtension:@"png"];
+    UIImage *image = [UIImage imageWithContentsOfFile:pngPath];
+    if (!image) {
+        static dispatch_once_t onceToken;
+        static UIImage *emptyImage = nil;
+        dispatch_once(&onceToken, ^{
+            UIGraphicsBeginImageContextWithOptions((CGSize){160, 144}, false, 1);
+            emptyImage = UIGraphicsGetImageFromCurrentImageContext();
+            UIGraphicsEndImageContext();
+        });
+        image = emptyImage;
+    }
+    cell.padding = 4;
+    cell.imageView.image = image;
+    cell.imageView.contentMode = UIViewContentModeScaleAspectFit;
+    
     return cell;
 }
 
+- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
+{
+    return 64;
+}
+
 - (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
 {
     return @"ROM Library";
@@ -46,9 +68,9 @@
     }];
 }
 
-- (BOOL)isModalInPresentation
+- (UIModalPresentationStyle)modalPresentationStyle
 {
-    return true;
+    return UIModalPresentationFormSheet;
 }
 
 @end

iOS/GBROMManager.m

@@ -60,7 +60,7 @@
         return self.romFile;
     }
     NSString *root = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, true).firstObject;
-    NSString *romDirectory = [root stringByAppendingPathComponent:_currentROM];
+    NSString *romDirectory = [root stringByAppendingPathComponent:rom];
     return [self romFileForDirectory:romDirectory];
 }
 

iOS/GBTableViewCell.h

@@ -0,0 +1,5 @@
+#import <UIKit/UIKit.h>
+
+@interface GBTableViewCell : UITableViewCell
+@property double padding;
+@end

iOS/GBTableViewCell.m

@@ -0,0 +1,11 @@
+#import "GBTableViewCell.h"
+
+@implementation GBTableViewCell
+
+-(void )layoutSubviews
+{
+    [super layoutSubviews];
+    self.imageView.frame = CGRectInset(self.imageView.frame, 0, self.padding);
+}
+
+@end

iOS/GBViewController.m

@@ -305,6 +305,44 @@ static void rumbleCallback(GB_gameboy_t *gb, double amp)
     _stopping = false;
 }
 
+- (UIImage *)imageFromData:(NSData *)data width:(unsigned)width height:(unsigned)height
+{
+    /* Convert the screenshot to a CGImageRef */
+    CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, data.bytes, data.length, NULL);
+    CGColorSpaceRef colorSpaceRef = CGColorSpaceCreateDeviceRGB();
+    CGBitmapInfo bitmapInfo = kCGBitmapByteOrderDefault;
+    CGColorRenderingIntent renderingIntent = kCGRenderingIntentDefault;
+    
+    CGImageRef iref = CGImageCreate(width,
+                                    height,
+                                    8,
+                                    32,
+                                    4 * width,
+                                    colorSpaceRef,
+                                    bitmapInfo,
+                                    provider,
+                                    NULL,
+                                    true,
+                                    renderingIntent);
+
+    UIImage *ret = [[UIImage alloc] initWithCGImage:iref];
+    CGColorSpaceRelease(colorSpaceRef);
+    CGDataProviderRelease(provider);
+    CGImageRelease(iref);
+    return ret;
+}
+
+- (void)saveStateToFile:(NSString *)file
+{
+    GB_save_state(&_gb, file.fileSystemRepresentation);
+    NSData *data = [NSData dataWithBytes:_gbView.previousBuffer
+                                  length:GB_get_screen_width(&_gb) *
+                                         GB_get_screen_height(&_gb) *
+                                         sizeof(*_gbView.previousBuffer)];
+    UIImage *screenshot = [self imageFromData:data width:GB_get_screen_width(&_gb) height:GB_get_screen_height(&_gb)];
+    [UIImagePNGRepresentation(screenshot) writeToFile:[file stringByAppendingPathExtension:@"png"] atomically:false];
+}
+
 - (void)postRun
 {
     [_audioLock lock];
@@ -316,7 +354,7 @@ static void rumbleCallback(GB_gameboy_t *gb, double amp)
     _audioClient = nil;
 
     GB_save_battery(&_gb, [GBROMManager sharedManager].batterySaveFile.fileSystemRepresentation);
-    GB_save_state(&_gb, [GBROMManager sharedManager].autosaveStateFile.fileSystemRepresentation);
+    [self saveStateToFile:[GBROMManager sharedManager].autosaveStateFile];
 }
 
 - (void)start