Adding a category to NSObject which can dynamically provide an array

of any class' subclasses (and direct subclasses, meaning only those
classes whose parent is the class to which the message was sent) via
two new class methods, +subclasses, and +directSubclasses.

diff --git a/ITCategory-NSObject.h b/ITCategory-NSObject.h
new file mode 100644 (file)
index 0000000..96c7e31
--- /dev/null
+++ b/ITCategory-NSObject.h
@@ -0,0 +1,24 @@
+/*
+ *     ITKit
+ *  ITCategory-NSObject.h
+ *    Category which extends NSObject
+ *
+ *  Original Author : Joseph Spiros <joseph.spiros@ithinksw.com>
+ *   Responsibility : Joseph Spiros <joseph.spiros@ithinksw.com>
+ *
+ *  Copyright (c) 2002 - 2004 iThink Software.
+ *  All Rights Reserved
+ *
+ */
+
+
+#import <Cocoa/Cocoa.h>
+
+
+@interface NSObject (ITCategory)
+
++ (NSArray *)subclasses;
++ (NSArray *)directSubclasses;
+
+
+@end

diff --git a/ITCategory-NSObject.m b/ITCategory-NSObject.m
new file mode 100644 (file)
index 0000000..09281e8
--- /dev/null
+++ b/ITCategory-NSObject.m
@@ -0,0 +1,129 @@
+#import "ITCategory-NSObject.h"
+#import <objc/objc-runtime.h>
+
+@implementation NSObject (ITCategory)
+
++ (NSArray *)subclasses
+{
+    NSMutableArray    *tempArray;
+    NSArray           *resultArray;
+    Class             *classes;
+    struct objc_class *superClass;
+    Class             *current;
+    int                count, newCount, index;
+
+    tempArray   = [[NSMutableArray allocWithZone:nil] initWithCapacity:12];
+    resultArray = nil;
+
+    if (tempArray)
+    {
+        classes = NULL;
+        count   = objc_getClassList(NULL, 0);
+        if (count)
+        {
+            classes = malloc(sizeof(Class) * count);
+            if (classes)
+            {
+                newCount = objc_getClassList(classes, count);
+                while (count < newCount)
+                {
+                    count = newCount;
+                    free(classes);
+                    classes = malloc(sizeof(Class) * count);
+                    if (classes)
+                        newCount = objc_getClassList(classes, count);
+                }
+                count = newCount;
+            }
+        }
+
+        if (classes)
+        {
+            const Class thisClass = [self class];
+            current = classes;
+
+            for (index = 0; index < count; ++index)
+            {
+                superClass = (*current)->super_class;
+                if (superClass)
+                {
+                    do
+                    {
+                        if (superClass == thisClass)
+                        {
+                            [tempArray addObject:*current];
+                            break;
+                        }
+                        superClass = superClass->super_class;
+                    } while (superClass);
+                }
+
+                ++current;
+            }
+
+            free(classes);
+        }
+
+        resultArray = [NSArray arrayWithArray:tempArray];
+        [tempArray release];
+    }
+
+    return resultArray;
+}
+
++ (NSArray *)directSubclasses
+{
+    NSMutableArray *tempArray;
+    NSArray        *resultArray;
+    Class          *classes;
+    Class          *current;
+    int             count, newCount, index;
+
+    tempArray   = [[NSMutableArray allocWithZone:nil] initWithCapacity:12];
+    resultArray = nil;
+
+    if (tempArray)
+    {
+        classes = NULL;
+        count   = objc_getClassList(NULL, 0);
+        if (count)
+        {
+            classes = malloc(sizeof(Class) * count);
+            if (classes)
+            {
+                newCount = objc_getClassList(classes, count);
+                while (count < newCount)
+                {
+                    count = newCount;
+                    free(classes);
+                    classes = malloc(sizeof(Class) * count);
+                    if (classes)
+                        newCount = objc_getClassList(classes, count);
+                }
+                count = newCount;
+            }
+        }
+
+        if (classes)
+        {
+            const Class thisClass = [self class];
+            current = classes;
+
+            for (index = 0; index < count; ++index)
+            {
+                if ((*current)->super_class == thisClass)
+                    [tempArray addObject:*current];
+                ++current;
+            }
+
+            free(classes);
+        }
+
+        resultArray = [NSArray arrayWithArray:tempArray];
+        [tempArray release];
+    }
+
+    return resultArray;
+}
+
+@end
\ No newline at end of file

diff --git a/ITFoundation.xcode/project.pbxproj b/ITFoundation.xcode/project.pbxproj
index 0ea001c..e7e51ca 100755 (executable)
--- a/ITFoundation.xcode/project.pbxproj
+++ b/ITFoundation.xcode/project.pbxproj
@@ -210,6 +210,8 @@
 //2A4
                2AB93A2C057059DC007E748F = {
                        children = (
+                               7C058DF7072F10530082E1E9,
+                               7C058DF8072F10530082E1E9,
                                2AB93A3005705A0C007E748F,
                                2AB93A3105705A0C007E748F,
                        );
@@ -595,6 +597,37 @@
 //7C2
 //7C3
 //7C4
+               7C058DF7072F10530082E1E9 = {
+                       fileEncoding = 4;
+                       isa = PBXFileReference;
+                       lastKnownFileType = sourcecode.c.h;
+                       path = "ITCategory-NSObject.h";
+                       refType = 4;
+                       sourceTree = "<group>";
+               };
+               7C058DF8072F10530082E1E9 = {
+                       fileEncoding = 4;
+                       isa = PBXFileReference;
+                       lastKnownFileType = sourcecode.c.objc;
+                       path = "ITCategory-NSObject.m";
+                       refType = 4;
+                       sourceTree = "<group>";
+               };
+               7C058DF9072F10530082E1E9 = {
+                       fileRef = 7C058DF7072F10530082E1E9;
+                       isa = PBXBuildFile;
+                       settings = {
+                               ATTRIBUTES = (
+                                       Public,
+                               );
+                       };
+               };
+               7C058DFA072F10530082E1E9 = {
+                       fileRef = 7C058DF8072F10530082E1E9;
+                       isa = PBXBuildFile;
+                       settings = {
+                       };
+               };
                7C97DC2C05B614300013E85F = {
                        fileEncoding = 4;
                        isa = PBXFileReference;
@@ -876,6 +909,7 @@
                                3D97137F05D9FBF40033607F,
                                3D97138A05D9FD6B0033607F,
                                376AF4DF06597CA900F0979E,
+                               7C058DF9072F10530082E1E9,
                        );
                        isa = PBXHeadersBuildPhase;
                        runOnlyForDeploymentPostprocessing = 0;
@@ -914,6 +948,7 @@
                                3D97138105D9FBFA0033607F,
                                3D97138B05D9FD6B0033607F,
                                376AF4E006597CA900F0979E,
+                               7C058DFA072F10530082E1E9,
                        );
                        isa = PBXSourcesBuildPhase;
                        runOnlyForDeploymentPostprocessing = 0;