--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/observer.c	Mon Aug 18 01:59:26 2008 +0800
@@ -0,0 +1,149 @@
+#include <stdio.h>
+#include "redraw_man.h"
+#include "observer.h"
+#include "tools.h"
+
+subject_t *subject_new(ob_factory_t *factory, void *obj, int obj_type) {
+    subject_t *subject;
+
+    subject = factory->subject_alloc(factory);
+    if(subject == NULL)
+	return NULL;
+
+    subject->obj = obj;
+    subject->obj_type = obj_type;
+    subject->flags = 0;
+    STAILQ_INIT(subject->observers);
+
+    return subject;
+}
+
+void subject_free(ob_factory_t *factory, subject_t *subject) {
+    observer_t *observer;
+
+    while((observer = STAILQ_HEAD(subject->observers))) {
+	STAILQ_REMOVE(subject->observers, observer_t, next, observer);
+	factory->observer_free(factory, observer);
+    }
+    factory->subject_free(factory, subject);
+}
+
+
+void subject_notify(ob_factory_t *factory, subject_t *subject, event_t *evt) {
+    observer_t *observer;
+
+    while(subject) {
+	for(observer = STAILQ_HEAD(subject->observers);
+	    observer != NULL;
+	    observer = STAILQ_NEXT(observer_t, next, observer)) {
+	    observer->hdr(evt, observer->arg);
+	}
+
+	if(subject->flags & SUBF_STOP_PROPAGATE)
+	    break;
+
+	subject = factory->get_parent_subject(factory, subject);
+    }
+}
+
+observer_t *subject_add_observer(ob_factory_t *factory,
+				 subject_t *subject,
+				 evt_handler hdr, void *arg) {
+    observer_t *observer;
+
+    observer = factory->observer_alloc(factory);
+    if(observer == NULL)
+	return NULL;
+    observer->hdr = hdr;
+    observer->arg = arg;
+
+    STAILQ_INS_TAIL(subject->observers, observer_t, next, observer);
+
+    return observer;
+}
+
+void subject_remove_observer(ob_factory_t *factory,
+			     subject_t *subject,
+			     observer_t *observer) {
+    STAILQ_REMOVE(subject->observers, observer_t, next, observer);
+    factory->observer_free(factory, observer);
+}
+
+#ifdef UNITTEST
+
+#include <CUnit/Basic.h>
+#include <stdlib.h>
+
+static subject_t *test_subject_alloc(ob_factory_t *factory) {
+    subject_t *subject;
+
+    subject = (subject_t *)malloc(sizeof(subject_t));
+    return subject;
+}
+
+static void test_subject_free(ob_factory_t *factory, subject_t *subject) {
+    free(subject);
+}
+
+static observer_t *test_observer_alloc(ob_factory_t *factory) {
+    observer_t *observer;
+
+    observer = (observer_t *)malloc(sizeof(observer_t));
+    return observer;
+}
+
+static void test_observer_free(ob_factory_t *factory, observer_t *observer) {
+    free(observer);
+}
+
+static subject_t *test_get_parent_subject(ob_factory_t *factory,
+					  subject_t *subject) {
+    return NULL;
+}
+
+static ob_factory_t test_factory = {
+    test_subject_alloc,
+    test_subject_free,
+    test_observer_alloc,
+    test_observer_free,
+    test_get_parent_subject
+};
+
+static void handler(event_t *evt, void *arg) {
+    int *cnt = (int *)arg;
+
+    CU_ASSERT(evt->type == EVT_MOUSE_OVER);
+    (*cnt)++;
+}
+
+void test_observer(void) {
+    subject_t *subject;
+    observer_t *observer;
+    event_t evt;
+    int cnt = 0;
+
+    subject = subject_new(&test_factory, NULL, 0);
+    subject->flags |= SUBF_STOP_PROPAGATE;
+    observer = subject_add_observer(&test_factory, subject,
+				    handler, &cnt);
+
+    evt.type = EVT_MOUSE_OVER;
+    evt.tgt = NULL;
+    evt.cur_tgt = NULL;
+    subject_notify(&test_factory, subject, &evt);
+    CU_ASSERT(cnt == 1);
+
+    subject_remove_observer(&test_factory, subject, observer);
+    subject_free(&test_factory, subject);
+}
+
+CU_pSuite get_observer_suite(void) {
+    CU_pSuite suite;
+
+    suite = CU_add_suite("Suite_observer", NULL, NULL);
+    CU_ADD_TEST(suite, test_observer);
+
+    return suite;
+}
+
+#endif /* UNITTEST */