add scrollbar widget.

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@832 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/rtgui/include/rtgui/widgets/scrollbar.h

@@ -0,0 +1,77 @@
+#ifndef __RTGUI_SCROLLBAR_H__
+#define __RTGUI_SCROLLBAR_H__
+
+#include <rtgui/rtgui.h>
+#include <rtgui/widgets/widget.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** Gets the type of a scrollbar */
+#define RTGUI_SCROLLBAR_TYPE       (rtgui_scrollbar_type_get())
+/** Casts the object to an rtgui_scrollbar */
+#define RTGUI_SCROLLBAR(obj)       (RTGUI_OBJECT_CAST((obj), RTGUI_SCROLLBAR_TYPE, rtgui_scrollbar_t))
+/** Checks if the object is an rtgui_scrollbar */
+#define RTGUI_IS_SCROLLBAR(obj)    (RTGUI_OBJECT_CHECK_TYPE((obj), RTGUI_SCROLLBAR_TYPE))
+
+#define RTGUI_DEFAULT_SB_WIDTH				100
+#define RTGUI_DEFAULT_SB_HEIGHT				16
+
+/* scrollbar status/positions*/
+#define SBS_UNKNOWN         0x0000
+#define SBS_LEFTARROW       0x0001
+#define SBS_RIGHTARROW      0x0002
+#define SBS_LEFTSPACE       0x0004
+#define SBS_RIGHTSPACE      0x0008
+#define SBS_HORZTHUMB       0x0010
+#define SBS_UPARROW         0x0020
+#define SBS_DOWNARROW       0x0040
+#define SBS_UPSPACE         0x0080
+#define SBS_DOWNSPACE       0x0100
+#define SBS_VERTTHUMB       0x0200
+
+struct rtgui_scrollbar
+{
+	/* inherit from widget */
+	struct rtgui_widget parent;
+
+	rt_uint8_t orient;
+	rt_uint8_t status;
+
+	/* page_step = width of scrollbar */
+	/* thumb size = line_step * page_step / (page_step - (button width * 2)) */
+	rt_int16_t line_step, page_step;
+
+	rt_int16_t thumb_position, thumb_size;
+
+	/* position 1:1 width of scrollbar */
+	rt_int16_t min_position, max_position;
+
+	rt_int16_t bar_width;
+
+	rt_bool_t (*on_scroll) (struct rtgui_widget* widget, struct rtgui_event* event);
+};
+typedef struct rtgui_scrollbar rtgui_scrollbar_t;
+
+rtgui_type_t *rtgui_scrollbar_type_get(void);
+
+struct rtgui_scrollbar* rtgui_scrollbar_create(int orient, rtgui_rect_t* r);
+void rtgui_scrollbar_destroy(struct rtgui_scrollbar* bar);
+
+void rtgui_scrollbar_set_range(struct rtgui_scrollbar* bar, int min, int max);
+rt_int16_t rtgui_scrollbar_get_value(struct rtgui_scrollbar* bar);
+void rtgui_scrollbar_set_value(struct rtgui_scrollbar* bar, rt_int16_t position);
+
+void rtgui_scrollbar_set_onscroll(struct rtgui_scrollbar* bar, rtgui_event_handler_ptr handler);
+void rtgui_scrollbar_set_orientation(struct rtgui_scrollbar* bar, int orientation);
+void rtgui_scrollbar_set_page_step(struct rtgui_scrollbar* bar, int step);
+void rtgui_scrollbar_set_line_step(struct rtgui_scrollbar* bar, int step);
+
+rt_bool_t rtgui_scrollbar_event_handler(struct rtgui_widget* widget, struct rtgui_event* event);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

components/rtgui/widgets/textbox.c

@@ -174,15 +174,12 @@ static void rtgui_textbox_onkey(struct rtgui_textbox* box, struct rtgui_event_kb
 		else if (box->position != 0)
 		{
 			/* remove current character */
-			if (box->position != 0)
-			{
-				char *c;
+			char *c;
 
-				/* remove character */
-				for (c = &box->text[box->position - 1]; c[1] != '\0'; c++)
-					*c = c[1];
-				*c = '\0';
-			}
+			/* remove character */
+			for (c = &box->text[box->position - 1]; c[1] != '\0'; c++)
+				*c = c[1];
+			*c = '\0';
 			box->position --;
 		}
 	}