[libr] Make PLItem more useful

I can't say that I like what's there even now, but at least PLItem can
be used without a lot of casting. Really, Ruamoko needs dictionary and
string classes so reading a property list can build more natural object
trees rather than this mess from when I knew too little.

ruamoko/include/PropertyList.h

@@ -4,7 +4,29 @@
 #include <plist.h>
 #include <Object.h>
 
-@interface PLItem: Object
+@class PLItem;
+
+@protocol PLDictionary
+- (int) count;
+- (int) numKeys;
+- (PLItem *) getObjectForKey:(string) key;
+- (PLItem *) allKeys;
+- addKey:(string) key value:(PLItem *) value;
+@end
+
+@protocol PLArray
+- (int) count;
+- (int) numObjects;
+- (PLItem *) getObjectAtIndex:(int) index;
+- addObject:(PLItem *) object;
+- insertObject:(PLItem *) object atIndex:(int) index;
+@end
+
+@protocol PLString
+- (string) string;
+@end
+
+@interface PLItem: Object <PLDictionary, PLArray, PLString>
 {
 	plitem_t    item;
 	int     own;
@@ -22,34 +44,20 @@
 - (pltype_t) type;
 @end
 
-@interface PLDictionary: PLItem
+@interface PLDictionary: PLItem <PLDictionary>
 + (PLDictionary *) new;
-
-- (int) count;
-- (int) numKeys;
-- (PLItem *) getObjectForKey:(string) key;
-- (PLItem *) allKeys;
-- addKey:(string) key value:(PLItem *) value;
 @end
 
-@interface PLArray: PLItem
+@interface PLArray: PLItem <PLArray>
 + (PLArray *) new;
-
-- (int) count;
-- (int) numObjects;
-- (PLItem *) getObjectAtIndex:(int) index;
-- addObject:(PLItem *) object;
-- insertObject:(PLItem *) object atIndex:(int) index;
 @end
 
 @interface PLData: PLItem
 + (PLData *) new:(void*) data size:(int) len;
 @end
 
-@interface PLString: PLItem
+@interface PLString: PLItem <PLString>
 + (PLString *) new:(string) str;
-
-- (string) string;
 @end
 
 #endif//__ruamoko_PropertyList_h

ruamoko/lib/PropertyList.r

@@ -94,6 +94,81 @@
 	return PL_Type (item);
 }
 
+- (int) count
+{
+	if ([self class] == [PLDictionary class]) {
+		return PL_D_NumKeys (item);
+	} else {
+		return PL_A_NumObjects (item);
+	}
+}
+
+- (int) numKeys
+{
+	return PL_D_NumKeys (item);
+}
+
+- (PLItem *) getObjectForKey:(string) key
+{
+	return [[PLItem itemClass: PL_ObjectForKey (item, key)] autorelease];
+}
+
+- (PLItem *) allKeys
+{
+	return [[PLItem itemClass: PL_D_AllKeys (item)] autorelease];
+}
+
+- addKey:(string) key value:(PLItem *) value
+{
+	if (!value.own) {
+		obj_error (self, 0, "add of unowned key/value to PLDictionary");
+		return self;
+	}
+	PL_D_AddObject (item, key, value.item);
+	value.own = 0;
+	[value release];
+	return self;
+}
+
+- (int) numObjects
+{
+	return PL_A_NumObjects (item);
+}
+
+- (PLItem *) getObjectAtIndex:(int) index
+{
+	return [[PLItem itemClass: PL_ObjectAtIndex (item, index)] autorelease];
+}
+
+- addObject:(PLItem *) object
+{
+	if (!object.own) {
+		obj_error (self, 0, "add of unowned object to PLArray");
+		return self;
+	}
+	PL_A_AddObject (item, object.item);
+	object.own = 0;
+	[object release];
+	return self;
+}
+
+- insertObject:(PLItem *) object atIndex:(int) index
+{
+	if (!object.own) {
+		obj_error (self, 0, "add of unowned object to PLArray");
+		return self;
+	}
+	PL_A_InsertObjectAtIndex (item, object.item, index);
+	object.own = 0;
+	[object release];
+	return self;
+}
+
+- (string) string
+{
+	return PL_String (item);
+}
+
 @end