RTGUI窗口绘制代码存在的bug

发布于 2012-12-19 02:59:21 浏览：3315 订阅该版

今天绘制RTGUIBuilder的rtgui_win控件，参考了RTGUI窗体绘制部分的代码，发现一个bug，源代码如下：
```/* window drawing */
void rtgui_theme_draw_win(struct rtgui_topwin* win)
{
	struct rtgui_dc* dc;
	rtgui_rect_t rect;

if (win->title == RT_NULL) return; /* no title and no board */

/* begin drawing */
	dc = rtgui_dc_begin_drawing(RTGUI_WIDGET(win->title));
	if (dc == RT_NULL) return;

/* get rect */
	rtgui_widget_get_rect(RTGUI_WIDGET(win->title), &rect);

/* draw border */
	if (win->flag & WINTITLE_BORDER)
	{
		rect.x2 -= 1; rect.y2 -= 1;
		RTGUI_WIDGET_FOREGROUND(win->title) = RTGUI_RGB(212, 208, 200);
		rtgui_dc_draw_hline(dc, rect.x1, rect.x2, rect.y1);
		rtgui_dc_draw_vline(dc, rect.x1, rect.y1, rect.y2);

RTGUI_WIDGET_FOREGROUND(win->title) = white;
		rtgui_dc_draw_hline(dc, rect.x1 + 1, rect.x2 - 1, rect.y1 + 1);
		rtgui_dc_draw_vline(dc, rect.x1 + 1, rect.y1 + 1, rect.y2 - 1);

RTGUI_WIDGET_FOREGROUND(win->title) = RTGUI_RGB(128, 128, 128);
		rtgui_dc_draw_hline(dc, rect.x1 + 1, rect.x2 - 1, rect.y2 - 1);
		rtgui_dc_draw_vline(dc, rect.x2 - 1, rect.y1 + 1, rect.y2);

RTGUI_WIDGET_FOREGROUND(win->title) = RTGUI_RGB(64, 64, 64);
		rtgui_dc_draw_hline(dc, rect.x1, rect.x2, rect.y2);
		rtgui_dc_draw_vline(dc, rect.x2, rect.y1, rect.y2 + 1);

/* shrink border */
		rtgui_rect_inflate(&rect, -WINTITLE_BORDER_SIZE);
	}

/* draw title */
	if (!(win->flag & WINTITLE_NO))
	{
		rt_uint32_t index;
		float r, g, b, delta;

if (win->flag & WINTITLE_ACTIVATE)
		{
			r = 10; g = 36; b = 106;
			delta = 150 / (float)(rect.x2 - rect.x1);
		}
		else
		{
			r = 128; g = 128; b = 128;
			delta = 64 / (float)(rect.x2 - rect.x1);
		}

RTGUI_WIDGET_FOREGROUND(win->title) = RTGUI_RGB(r, g, b);
		for (index = rect.x1; index < rect.x2 + 1; index ++)
		{
			rtgui_dc_draw_vline(dc, index, rect.y1, rect.y2);
			r += delta; g += delta; b += delta;
		}

if (win->flag & WINTITLE_ACTIVATE)
		{
			RTGUI_WIDGET_FOREGROUND(win->title) = white;
		}
		else
		{
			RTGUI_WIDGET_FOREGROUND(win->title) = RTGUI_RGB(212, 208, 200);
		}

rect.x1 += 4;
		rect.y1 += 2; rect.y2 = rect.y1 + WINTITLE_CB_HEIGHT;
		rtgui_dc_draw_text(dc, rtgui_wintitle_get_title(win->title), &rect);

if (win->flag & WINTITLE_CLOSEBOX)
		{
			/* get close button rect */
			rtgui_rect_t box_rect = {0, 0, WINTITLE_CB_WIDTH, WINTITLE_CB_HEIGHT};
			rtgui_rect_moveto_align(&rect, &box_rect, RTGUI_ALIGN_CENTER_VERTICAL | RTGUI_ALIGN_RIGHT);
			box_rect.x1 -= 3; box_rect.x2 -= 3;
			rtgui_dc_fill_rect(dc, &box_rect);

/* draw close box */
			if (win->flag & WINTITLE_CB_PRESSED)
			{
				rtgui_dc_draw_border(dc, &box_rect, RTGUI_BORDER_SUNKEN);
				RTGUI_WIDGET_FOREGROUND(win->title) = red;
				rtgui_dc_draw_word(dc, box_rect.x1, box_rect.y1 + 6, 7, close_byte);
			}
			else
			{
				rtgui_dc_draw_border(dc, &box_rect, RTGUI_BORDER_RAISE);
				RTGUI_WIDGET_FOREGROUND(win->title) = black;
				rtgui_dc_draw_word(dc, box_rect.x1 - 1, box_rect.y1 + 5, 7, close_byte);
			}
		}
	}

rtgui_dc_end_drawing(dc);
}
```
在绘制title代码中发现有如下一段代码：
```RTGUI_WIDGET_FOREGROUND(win->title) = RTGUI_RGB(r, g, b);
		for (index = rect.x1; index < rect.x2 + 1; index ++)
		{
			rtgui_dc_draw_vline(dc, index, rect.y1, rect.y2);
			r += delta; g += delta; b += delta;
		}```
这个我猜原本的意思是绘制一个渐变的标题栏，但是设置颜色的的代码放在了循环语句外面，这个绘制出来的其实就是在绘制一个填充的矩形，下面的颜色计算完全没有用上，而且还使用的是浮点型数据。
![修正后.png](https://oss-club.rt-thread.org/uploads/3230_a8bcfbd96eb2f3d0ec8f541c3d68cae6.png)

![未命名.jpg](https://oss-club.rt-thread.org/uploads/4345_246fb58019e0412f0387be282258c7d6.jpg)