Adding a category to NSObject which can dynamically provide an array

[ITFoundation.git] / ITCategory-NSObject.m

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
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