Backend printing bundle system changes

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/gui/trunk@19705 72102866-910b-0410-8b05-ffd578937521

Source/GSPrinting.m

@@ -0,0 +1,234 @@
+/** <title>GSPrinting.m</title>
+
+   <abstract>GSPrinting loads the proper bundle for the printing backend.</abstract>
+
+   Copyright (C) 2004 Free Software Foundation, Inc.
+
+   Author:  Chad Elliott Hardin <cehardin@mac.com>
+   Date: June 2004
+   
+   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; see the file COPYING.LIB.
+   If not, write to the Free Software Foundation,
+   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+*/ 
+
+#include "GNUstepGUI/GSPrinting.h"
+#include <Foundation/NSBundle.h>
+#include <Foundation/NSEnumerator.h>
+#include <Foundation/NSDebug.h>
+#include <Foundation/NSPathUtilities.h>
+#include <Foundation/NSArray.h>
+#include <Foundation/NSFileManager.h>
+#include <Foundation/NSUserDefaults.h>
+#include "AppKit/NSPanel.h"
+
+static NSBundle *printingBundle = nil;
+
+
+/**
+  <unit>
+  <heading>Class Description</heading>
+  <p>
+  GSPrinting is used by all of the NSPrint and the NSPageLayout
+  class(es) so that a printing backend bundle can be loaded.  It
+  first utilizes NSUserDefaults to find the user's preferred printing
+  backend bundle.  It looks for the key GSPrinting.  If the user's
+  preferred bundle cannot be loaded, it tries to load any working
+  printing bundle.
+  </p>
+  </unit>
+*/ 
+@implementation GSPrinting
+
++(NSBundle*) loadPrintingBundle: (NSString*) bundleName
+{
+  NSString *path;
+  NSEnumerator *libraryPathsEnumerator;
+    
+  bundleName = [bundleName stringByAppendingString: @".bundle"];	
+    
+  NSDebugLLog(@"GSPrinting", @"Looking for %@", bundleName);
+    
+  libraryPathsEnumerator = [NSStandardLibraryPaths() objectEnumerator];
+    
+  while( (path = [libraryPathsEnumerator nextObject]) )
+  {
+    path = [path stringByAppendingPathComponent: @"Bundles"];
+	  path = [path stringByAppendingPathComponent: @"GSPrinting"];
+  	path = [path stringByAppendingPathComponent: bundleName];
+
+	  if ([[NSFileManager defaultManager] fileExistsAtPath: path])
+	  {
+	    NSBundle *bundle;
+	    
+	    bundle = [NSBundle bundleWithPath: path];
+	    if( [bundle load] == NO )
+	    {
+		    NSDebugLLog(@"GSPrinting", @"Error loading printing bundle at %@", path);
+        return nil;
+	    }
+	    else
+	    {
+        //one last check to make sure the principle class can be loaded
+        if( [bundle principalClass] == Nil)
+        {
+          NSDebugLLog(@"GSPrinting", @"Error loading principal class from printing bundle at %@", path);
+	        return nil;
+        }
+        //if we get here, finally, then everything should be ok, barring errors from later in loading resources.
+        NSDebugLLog(@"GSPrinting", @"Loaded printing bundle at %@", path);
+		    return bundle;
+	    }
+	  }
+  }
+    
+  NSDebugLLog(@"GSPrinting", @"Unable to find printing bundle %@", bundleName);
+  return nil;
+}
+
+
+
++(NSBundle*) loadAnyWorkingPrintingBundle
+{
+  NSBundle *bundle;
+    
+  if( (bundle = [GSPrinting loadPrintingBundle: @"GSCUPS"]) )
+    return bundle;
+	
+  if( (bundle = [GSPrinting loadPrintingBundle: @"GSLPR"]) )
+	  return bundle;
+	
+  if( (bundle = [GSPrinting loadPrintingBundle: @"GSWin32"]) )
+    return bundle;
+	
+  return nil;
+}
+
+
+
++ (NSBundle*) printingBundle
+{
+  NSString *defaultBundleName;
+  NSBundle *bundle;
+    
+  if( printingBundle )
+  {
+	  return printingBundle;
+  }
+    
+  NSDebugLLog(@"GSPrinting", @"Bundle has not been loaded.  Loading in progress...");
+    
+  defaultBundleName = [[NSUserDefaults standardUserDefaults] stringForKey: @"GSPrinting"];
+    
+  /*Which Printing Bundle?*/
+  if( defaultBundleName == nil )
+  {
+	  NSDebugLLog(@"GSPrinting", @"User did not set a printing bundle, trying till something works");
+	  bundle = [GSPrinting loadAnyWorkingPrintingBundle];
+	  if( bundle == nil )
+	  {
+	    NSDebugLLog(@"GSPrinting", @"Could not load any working printing bundle");
+	    NSRunAlertPanel(@"GNUstep Printing Backend System", @"Could not open any working printing bundle.  Printing will not work.", @"Ok", NULL, NULL );
+	    return nil;
+	  }
+  }
+  else
+  {	
+	  NSDebugLLog(@"GSPrinting", @"User set %@ as the printing bundle", defaultBundleName);
+    
+    bundle = [GSPrinting loadPrintingBundle: defaultBundleName];
+    if( bundle == nil )
+	  {
+	    NSDebugLLog(@"GSPrinting", @"User set %@ as the printing bundle but that did not work.  Will try to find anything that will work", defaultBundleName);
+	    bundle = [GSPrinting loadAnyWorkingPrintingBundle];
+	    if( bundle == nil )
+	    {
+		    NSDebugLLog(@"GSPrinting", @"Could not load any working printing bundle");
+		    NSRunAlertPanel(@"GNUstep Printing Backend System", @"Could not open any working printing bundle.  Printing will not work.", @"Ok", NULL, NULL );
+		    return nil;
+	    }
+	    else
+	    {
+		    NSString *msg;
+		    msg = [NSString stringWithFormat: @"Your chosen printing bundle, %@, could not be loaded.  %@ was loaded instead", defaultBundleName, [[bundle bundlePath] lastPathComponent]];
+		    NSRunAlertPanel(@"GNUstep Printing Backend System", msg, @"Ok", NULL, NULL );
+	    }
+	  }
+  }
+  
+  printingBundle = bundle;
+  [printingBundle retain];
+  return printingBundle;
+}
+
+@end
+
+
+
+
+
+
+
+/**
+  <unit>
+  <heading>Class Description</heading>
+  <p>
+  GSPrintingPrincipleClass is the base class that all
+  Printing backend bundles should use as their principle
+  class.  Subclasses are responsible for the allocating
+  of that bundle's particular NSPrint, NSPageLayout, and
+  GSPrintOperation sublclassed objects.
+  </p>
+  </unit>
+*/ 
+@implementation GSPrintingPrincipalClass : NSObject
+{
+}
+
++(Class) pageLayoutClass
+{
+ return Nil;
+}
+
++(Class) printInfoClass
+{
+ return Nil;
+}
+
+
++(Class) printOperationClass
+{
+ return Nil;
+}
+
++(Class) printPanelClass
+{
+ return Nil;
+}
+
+
++(Class) printerClass
+{
+ return Nil;
+}
+
++(Class) gsPrintOperationClass
+{
+ return Nil;
+}
+
+
+@end