libs-gui/Source/GSModelLoaderFactory.m

/** <title>GSModelLoaderFactory</title>

   <abstract>Model loader framework</abstract>

   Copyright (C) 1997, 1999 Free Software Foundation, Inc.

   Author:  Gregory John Casamento <greg_casamento@yahoo.com>
   Date: 2005
   
   This file is part of the GNUstep GUI Library.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.
   
   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this library;
   If not, write to the Free Software Foundation,
   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/ 

#include <Foundation/Foundation.h>
#include <AppKit/AppKit.h>
#include "GNUstepGUI/GSModelLoaderFactory.h"
#include "GNUstepBase/GSObjCRuntime.h"

@implementation GSModelLoader
+ (NSString *) type
{
  return nil;
}

+ (float) priority
{
  return 0.0;
}

- (BOOL) loadModelData: (NSData *)data
     externalNameTable: (NSDictionary *)context
              withZone: (NSZone *)zone
{
  [NSException raise: NSInternalInconsistencyException
	       format: @"Abstract model loader."];
  return NO;
}

- (BOOL) loadModelFile: (NSString *)fileName
     externalNameTable: (NSDictionary *)context
              withZone: (NSZone *)zone
{
  [NSException raise: NSInternalInconsistencyException
	       format: @"Abstract model loader."];
  return NO;
}

+ (NSComparisonResult) _comparePriority: (Class)loader
{
  NSComparisonResult result = NSOrderedSame;

  if([self priority] < [loader priority])
    {
      result = NSOrderedAscending;
    }
  if([self priority] > [loader priority])
    {
      result = NSOrderedDescending;
    }

  return result;
} 
@end

static NSMutableDictionary *_modelMap = nil;

@implementation GSModelLoaderFactory
+ (void) initialize
{
  NSArray *classes = GSObjCAllSubclassesOfClass([GSModelLoader class]);
  NSEnumerator *en = [classes objectEnumerator];
  Class cls = nil;
  
  while((cls = [en nextObject]) != nil)
    {
      [self registerModelLoaderClass: cls];
    }
}

+ (void) registerModelLoaderClass: (Class)aClass
{
  if(_modelMap == nil)
    {
      _modelMap = [[NSMutableDictionary alloc] initWithCapacity: 5];
    }

  [_modelMap setObject: aClass forKey: (NSString *)[aClass type]];
}

+ (Class)classForType: (NSString *)type
{
  return [_modelMap objectForKey: type];
}

+ (NSString *) supportedModelFileAtPath: (NSString *)modelPath
{
  NSString *result = nil;
  NSFileManager	*mgr = [NSFileManager defaultManager];
  NSString *ext = [modelPath pathExtension];

  if([ext isEqual: @""])
    {
      NSArray *objectArray = [_modelMap allValues];
      NSArray *sortedArray = [objectArray sortedArrayUsingSelector: 
					    @selector(_comparePriority:)];
      NSEnumerator *oen = [sortedArray objectEnumerator];
      Class cls = nil;

      while((cls = [oen nextObject]) != nil && result == NO)
	{
	  NSString *path = [modelPath stringByAppendingPathExtension: 
					(NSString *)[cls type]];
	  if([mgr isReadableFileAtPath: path])
	    {
	      result = path;
	    }
	}
    }
  else
    {
      if([_modelMap objectForKey: ext] != nil)
	{
	  if([mgr isReadableFileAtPath: modelPath])
	    {
	      result = modelPath;
	    }
	} 
    }
  
  return result;
}

+ (GSModelLoader *)modelLoaderForFileType: (NSString *)type
{
  Class aClass = [GSModelLoaderFactory classForType: type];
  GSModelLoader *loader = nil;

  if(aClass != nil)
    {
      loader = AUTORELEASE([[aClass alloc] init]);
    }
  else
    {
      [NSException raise: NSInternalInconsistencyException
		   format: @"Unable to find model loader class."];
    }

  return loader;
}

+ (GSModelLoader *)modelLoaderForFileName: (NSString *)modelPath
{
  NSString *path = [GSModelLoaderFactory supportedModelFileAtPath: modelPath];
  GSModelLoader *result = nil;

  if(path != nil)
    {
      NSString *ext = [path pathExtension];
      result = [self modelLoaderForFileType: ext];
    }
  
  return result;  
}
@end