VPItemLoaderDelegate.m

// VoodooPad
//
// Copyright (C) 2004-2018 Primate Labs Inc.  All Rights Reserved.
//////////////////////////////////////////////////////////////////////////////

#import "VPQTTabViewController.h"

NSString* const VPItemScheme = @"x-voodoopad-item";

@interface VPItemLoaderDelegate : NSObject <AVAssetResourceLoaderDelegate>
@property (nonatomic, strong) VPItem* item;
@end

@implementation VPItemLoaderDelegate

- (instancetype)initWithItem:(VPItem*)item
{
    self = [super init];
    if (self) {
        self.item = item;
    }
    return self;
}
/*!
 *  is scheme supported
 */
- (BOOL) schemeSupported:(NSString *)scheme
{
    if ([scheme isEqualToString:VPItemScheme]) {
        return YES;
    }
    return NO;
}

- (void) reportError:(AVAssetResourceLoadingRequest *) loadingRequest withErrorCode:(int) error
{
    NSLog(@"%d", error);
}

// https://github.com/leshkoapps/AVAssetResourceLoader/blob/6f633a5c6568ad42dad287280799eb139463d1e6/ResourceLoader/LSFilePlayerResourceLoader.m
- (BOOL) resourceLoader:(AVAssetResourceLoader *)resourceLoader shouldWaitForLoadingOfRequestedResource:(AVAssetResourceLoadingRequest *)loadingRequest
{
    NSURL *resourceURL = [loadingRequest.request URL];
    if ([resourceURL.scheme isEqualToString:VPItemScheme]) {
        NSData* itemData = [self.item data];

        long long offset = loadingRequest.dataRequest.requestedOffset;
        long length = loadingRequest.dataRequest.requestedLength;

        if (offset >= [itemData length]) {
            offset = [itemData length] - 1;
        }

        if ((offset + length) >= [itemData length]) {
            length = [itemData length] - offset;
        }

        const char* itemBuffer = (const char*) [itemData bytes];
        NSData* requestData = [NSData dataWithBytes:(itemBuffer + offset) length:length];

        if (loadingRequest.contentInformationRequest) {
            NSString* uti = [[self item] metaValueForKey:VPUTIMetaName];

            loadingRequest.contentInformationRequest.contentType = uti;
            loadingRequest.contentInformationRequest.contentLength = [itemData length];
            loadingRequest.contentInformationRequest.byteRangeAccessSupported = YES;
        }

        [loadingRequest.dataRequest respondWithData:requestData];

        [loadingRequest finishLoading];


        return YES;
    }

    return NO;
}

@end

@implementation VPQTTabViewController

- (void)loadMov
{
    NSString* scratch = [NSString stringWithFormat:@"%@://%@", VPItemScheme, [[self item] uuid]];
    NSURL* url = [NSURL URLWithString:scratch];

    AVURLAsset* asset = [AVURLAsset assetWithURL:url];
    VPItemLoaderDelegate* delegate = [[VPItemLoaderDelegate alloc] initWithItem:[self item]];
    AVAssetResourceLoader *resourceLoader = asset.resourceLoader;
    [resourceLoader setDelegate:delegate queue:dispatch_queue_create("VPItemLoaderDelegate", nil)];

    AVPlayerItem* playerItem = [AVPlayerItem playerItemWithAsset:asset];
    AVPlayer* player = [AVPlayer playerWithPlayerItem:playerItem];

    movieView.player = player;
}

@end