GeneratePreviewForURL.m

#import "Foundation/Foundation.h"
#import "CoreFoundation/CoreFoundation.h"
#import "CoreServices/CoreServices.h"

#import "QuickLook/QuickLook.h"

#import "Templater.h"
#import "CharFilter.h"
#import "AsciiCharFilter.h"

/**
 * read the first 4k from the url
 */
NSData* readFirstBytes(CFURLRef url) {
  NSFileHandle* filehandle = [NSFileHandle fileHandleForReadingFromURL:(NSURL*)url error:nil];
  if (!filehandle) {
    NSLog(@"got no filehandle");
  }

  return [filehandle readDataOfLength:4096];
}

/**
 * converts the given data to a ascii string representation
 * charachters not printable by ascii are left out
 */
NSString* createAscii(NSData* data) {
  NSMutableString* html = [[NSMutableString new] autorelease];

  [html appendString:@"<code>"];

  NSMutableString* bufferAsNsString = [NSMutableString new] ;//[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
  const char* bytes = (const char*)[data bytes];
  for (int i=0; i<[data length]; i++) {
    [bufferAsNsString appendFormat:@"%c", bytes[i]];
  }
  CFStringRef help = (CFStringRef)bufferAsNsString;
  CFStringRef escaped = CFXMLCreateStringByEscapingEntities(kCFAllocatorDefault, help, NULL);
  [bufferAsNsString release];
  NSString* stuff = [(NSString*)escaped stringByReplacingOccurrencesOfString:@"\r\n" withString:@"<br/>"];
  stuff = [stuff stringByReplacingOccurrencesOfString:@"\r" withString:@"<br/>"];
  stuff = [stuff stringByReplacingOccurrencesOfString:@"\n" withString:@"<br/>"];
  stuff = [stuff stringByReplacingOccurrencesOfString:@" " withString:@"&nbsp;"];
  [html appendString:(NSString*)stuff];

  CFRelease(escaped);

  [html appendString:@"</code>"];

  return html;
}

/**
 * create a html table from the data
 */
NSString* createTable(NSData* data,
                      int itemsPerRow,
                      NSString* format,
                      NSString* className,
                      CharFilter* filter) {
  NSMutableString* html = [[NSMutableString new] autorelease];
  [html appendFormat:@"<table class=\"striped %@\" cellspacing=\"0\">", className];
  [html appendString:@"<tr><th></th>"];
  {
    CFIndex i = 0;
    for (i=0; i<itemsPerRow; i++) {
      [html appendString:[NSString stringWithFormat:@"<th>%02lX</th>", i]];
    }

  }
  [html appendString:@"</tr>"];

  Boolean newLine = true;
  int count = 0;
  int totalCount = 0;
  {
    NSUInteger i;
    for (i=0; i<[data length]; i++) {
      if (newLine) {
        [html appendString:@"<tr class=\"striped\">"];
        [html appendString:[NSString stringWithFormat:@"<th>%04lX</th>", (unsigned long)i]] ;
        newLine = false;
      }

      const unichar c = ((const unsigned char*)[data bytes])[i];
      NSString* idString = [NSString stringWithFormat:@"%@-%d", className, totalCount];
      if ([filter filter:c]) {
        [html appendString:[NSString stringWithFormat:format, idString, c]];
      } else {
        [html appendString:[NSString stringWithFormat:@"<td id=\"%@\" class=\"linkedTable\">&nbsp;</td>", idString]];
      }
      count++;
      totalCount++;

      if (count % itemsPerRow == 0) {
        newLine = true;
        [html appendString:@"</tr>"];
        count = 0;
      }
    }
  }
  if (count > 0) {
    [html appendString:@"</tr>"];
  }

  [html appendString:@"</table>"];
  return html;
}

NSString* getTemplateFromBundle(NSBundle *bundle)
{
  NSURL* templateUrl = [NSURL
                          fileURLWithPath:[bundle
                                            pathForResource:@"template"
                                                     ofType:@"dhtml"]];
  if (!templateUrl) {
    NSLog(@"templateUrl not found");
    return nil;
  }
  NSLog(@"%@", [templateUrl path]);

  NSString* template = [NSString
                          stringWithContentsOfURL:templateUrl
                                         encoding:(NSStringEncoding)NSUTF8StringEncoding error:nil];
  if (!template) {
    NSLog(@"could not load from template");
    return nil;
  }
  return template;
}

NSData * resourceAsNSData(NSBundle *bundle, NSString *resource, NSString *extension) {
  return [NSData dataWithContentsOfURL:[bundle URLForResource:resource withExtension:extension]];
}

OSStatus GeneratePreviewForURL(void *thisInterface,
                               QLPreviewRequestRef preview,
                               CFURLRef url,
                               CFStringRef contentTypeUTI,
                               CFDictionaryRef options) {
  @autoreleasepool {
    // open bundle
    NSBundle* bundle = [NSBundle bundleWithIdentifier:@"com.flopcode.hexql"];

    if (!bundle) {
      NSLog(@"could not find bundle");
      return 1;
    }

    NSData* firstBytes = readFirstBytes(url);
    if (firstBytes) {
      NSMutableDictionary* templateData = [[[NSMutableDictionary alloc]init]autorelease];
      [templateData
        setObject:(NSString*)(CFURLGetString(url))
           forKey:@"path"];
      [templateData
        setObject:createTable(firstBytes, 16, @"<td id=\"%@\">%02X </td>", @"hex", [[[CharFilter alloc]init] autorelease])
           forKey:@"hextable"];
      [templateData
        setObject:createTable(firstBytes, 16, @"<td id=\"%@\">%c</td>", @"ascii", [[[AsciiCharFilter alloc]init]autorelease])
           forKey:@"asciitable"];
      [templateData
        setObject:createAscii(firstBytes)
           forKey:@"ascii"];
      [templateData
        setObject:[[NSURL fileURLWithPath:[bundle resourcePath]] absoluteString]
           forKey:@"resourcepath"];
      @try {
        NSString* html = [templateData applyToTemplate:getTemplateFromBundle(bundle)];
        /*
          NSString* debug = [[NSUserDefaults standardUserDefaults] stringForKey:@"HexQL.debug"];
          if ([debug compare:@"yes"] == NSOrderedSame) {
          BOOL res = [html
          writeToFile:@"/Users/gizmo/tmp/out.html"
          atomically:YES
          encoding:NSUTF8StringEncoding
          error:nil];
          }
        */

        NSDictionary *properties = @{
        (__bridge NSString *)kQLPreviewPropertyTextEncodingNameKey : @"UTF-8",
        (__bridge NSString *)kQLPreviewPropertyMIMETypeKey : @"text/html",
        (__bridge NSString *)kQLPreviewPropertyWidthKey : [NSNumber numberWithInt:870],
        (__bridge NSString *)kQLPreviewPropertyHeightKey : [NSNumber numberWithInt:600],
        (__bridge NSString *)kQLPreviewPropertyAttachmentsKey : @{
            @"style.css" : @{
            (__bridge NSString *)kQLPreviewPropertyMIMETypeKey : @"text/css",
            (__bridge NSString *)kQLPreviewPropertyAttachmentDataKey: resourceAsNSData(bundle, @"style", @"css")
            },
            @"jquery.ui.tabs.css" : @{
            (__bridge NSString *)kQLPreviewPropertyMIMETypeKey : @"text/css",
            (__bridge NSString *)kQLPreviewPropertyAttachmentDataKey: resourceAsNSData(bundle, @"jquery.ui.tabs", @"css")
            },
            @"jquery-1.2.3.js" : @{
            (__bridge NSString *)kQLPreviewPropertyMIMETypeKey : @"text/javascript",
            (__bridge NSString *)kQLPreviewPropertyAttachmentDataKey: resourceAsNSData(bundle, @"jquery-1.2.3", @"js")
            },
            @"jquery.ui.tabs.js" : @{
            (__bridge NSString *)kQLPreviewPropertyMIMETypeKey : @"text/javascript",
            (__bridge NSString *)kQLPreviewPropertyAttachmentDataKey: resourceAsNSData(bundle, @"jquery.ui.tabs", @"js")
            }
          }
        };
        NSData* htmlData = [html dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:true];
        QLPreviewRequestSetDataRepresentation(preview,
                                              CFDataCreate(NULL, [htmlData bytes], [htmlData length]),
                                              kUTTypeHTML,
                                              (__bridge CFDictionaryRef)properties);
      } @catch (NSException* e) {
        NSLog(@"%@", [e reason]);
        return 1;
      }
    }
  }
  return noErr;
}

void CancelPreviewGeneration(void* thisInterface, QLPreviewRequestRef preview)
{
}