/* * 程序清单:DC Buffer演示 * * 这个例子会在创建出的view上进行DC Buffer的演示 */ #include "demo_view.h" #include #include #include #include /* * view的事件处理函数 */ static rt_bool_t dc_buffer_event_handler(struct rtgui_object *object, rtgui_event_t *event) { struct rtgui_widget *widget = RTGUI_WIDGET(object); struct rtgui_dc *dc_buffer; /* 仅对PAINT事件进行处理 */ if (event->type == RTGUI_EVENT_PAINT) { struct rtgui_dc *dc; rtgui_rect_t rect; /* * 因为用的是demo view,上面本身有一部分控件,所以在绘图时先要让demo view * 先绘图 */ rtgui_container_event_handler(object, event); dc_buffer = (struct rtgui_dc*)widget->user_data; /* 获得控件所属的DC */ dc = rtgui_dc_begin_drawing(widget); /* 如果不能正常获得DC,返回(如果控件或父控件是隐藏状态,DC是获取不成功的) */ if (dc == RT_NULL) return RT_FALSE; /* 获得demo view允许绘图的区域 */ demo_view_get_logic_rect(RTGUI_CONTAINER(widget), &rect); rect.x1 += 10; rect.y1 += 10; rtgui_dc_blit(dc_buffer, NULL, dc, &rect); /* 绘图完成 */ rtgui_dc_end_drawing(dc); } else { /* 其他事件,调用默认的事件处理函数 */ return rtgui_container_event_handler(object, event); } return RT_FALSE; } /* 创建用于DC Buffer操作演示用的视图 */ rtgui_container_t *demo_view_dc_buffer() { rtgui_container_t *view; struct rtgui_dc *dc_buffer=RT_NULL; if (dc_buffer == RT_NULL) { rtgui_rect_t rect = {0, 0, 50, 50}; /* 创建 DC Buffer,长 50,宽 50 */ dc_buffer = rtgui_dc_buffer_create(50, 50); RTGUI_DC_BC(dc_buffer) = blue; rtgui_dc_fill_rect(dc_buffer, &rect); RTGUI_DC_FC(dc_buffer) = red; rtgui_dc_draw_circle(dc_buffer, 25, 25, 10); } view = demo_view("缓冲DC演示"); if (view != RT_NULL) /* 设置成自己的事件处理函数 */ rtgui_object_set_event_handler(RTGUI_OBJECT(view), dc_buffer_event_handler); RTGUI_WIDGET(view)->user_data = (rt_uint32_t)dc_buffer; return view; }