--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/drag/main.c	Sat Dec 06 15:40:23 2008 +0800
@@ -0,0 +1,109 @@
+/*! \file
+ *
+ * svg2code_ex is an example that show programmers how to create a
+ * menu with MadButterfly.
+ *
+ */
+#include <stdio.h>
+#include <mb.h>
+#include "menu.h"
+
+typedef struct _engine engine_t;
+struct _engine {
+    X_MB_runtime_t *rt;
+    redraw_man_t *rdman;
+    menu_t *menu;
+    int state;
+    co_aix orx,ory;
+    int start_x,start_y;
+};
+engine_t *engine_init()
+{
+
+    X_MB_runtime_t *rt;
+    rt = X_MB_new(":0.0", 800, 600);
+    engine_t *en = (engine_t *) malloc(sizeof(engine_t));
+
+    en->rt = rt;
+    en->rdman =  X_MB_rdman(rt);
+    return en;
+}
+void engine_close(engine_t *en)
+{
+    /*
+     * Start handle connections, includes one to X server.
+     * User start to interact with the application.
+     */
+    X_MB_handle_connection(en->rt);
+
+    /*
+     * Clean
+     */
+    menu_free(en->menu);
+    X_MB_free(en->rt);
+    free(en);
+}
+#define COORD_SHOW(group) coord_show(group);rdman_coord_changed(X_MB_rdman(ex_rt->rt), group)
+#define COORD_HIDE(group) coord_hide(group);rdman_coord_changed(X_MB_rdman(ex_rt->rt), group)
+
+
+void coord_move(coord_t *c, co_aix x, co_aix y)
+{
+    c->matrix[2] = x;
+    c->matrix[5] = y;
+}
+
+
+static void cursor_press_handler(event_t *evt, void *arg) {
+    engine_t *en = (engine_t *) arg;
+    mouse_event_t *mev = (mouse_event_t *) evt;
+
+    en->start_x = mev->x;
+    en->start_y = mev->y;
+    en->orx = en->menu->cursor->matrix[2];
+    en->ory = en->menu->cursor->matrix[5];
+    printf("pressed %g %g\n",en->orx,en->ory);
+    en->state = 1;
+}
+
+static void cursor_release_handler(event_t *evt, void *arg) {
+    engine_t *en = (engine_t *) arg;
+    printf("up\n");
+    en->state = 0;
+}
+
+static void cursor_move_handler(event_t *evt, void *arg) {
+    engine_t *en = (engine_t *) arg;
+    mouse_event_t *mev = (mouse_event_t *) evt;
+
+    if (en->state) {
+        printf("move to (%d %d)\n", mev->x,mev->y);
+        coord_move(en->menu->cursor,en->orx + (mev->x-en->start_x),en->ory + (mev->y-en->start_y));
+        rdman_coord_changed(en->rdman, en->menu->cursor);
+        /* Update changed part to UI. */
+        rdman_redraw_changed(en->rdman);
+    }
+}
+
+int main(int argc, char * const argv[]) {
+    subject_t *subject;
+    engine_t *en;
+
+    en = engine_init();
+    en->menu = menu_new(en->rdman, en->rdman->root_coord);
+
+    /*
+     * Register observers to subjects of events for objects.
+     */
+    subject = coord_get_mouse_event(en->menu->cursor);
+    subject_add_event_observer(subject,  EVT_MOUSE_BUT_PRESS, cursor_press_handler, en);
+    subject_add_event_observer(subject,  EVT_MOUSE_BUT_RELEASE, cursor_release_handler, en);
+    subject_add_event_observer(subject,  EVT_MOUSE_MOVE, cursor_move_handler, en);
+
+
+    engine_close(en);
+
+    return 0;
+}
+
+/* vim: set ts=4 */