设定xfce工具栏图标背景的几种方法

来源：互联网发布：java基础入门编辑：程序博客网时间：2024/05/20 07:59

现在有这么一个需求，需要将xfce工具栏上图标的背景设置成指定的背景，那么可以用下面几种方法：

1.修改~/.gtkrc-2.0，这个方法最简单，可以参考：

http://wiki.archlinux.org/index.php/Xfce_%28%E7%AE%80%E4%BD%93%E4%B8%AD%E6%96%87%29#.E5.A6.82.E4.BD.95.E8.AE.A9.E6.A1.8C.E9.9D.A2.E5.9B.BE.E6.A0.87.E6.A0.87.E7.AD.BE.E5.AD.97.E4.BD.93.E8.83.8C.E6.99.AF.E9.80.8F.E6.98.8E

C代码

gtk_widget_set_app_paintable (GTK_WIDGET (item), TRUE);
//设定控件显示时的回调函数
g_signal_connect(item, "expose-event",G_CALLBACK(transparent_expose), NULL)

C代码

static gboolean
transparent_expose (GtkWidget *item,
GdkEventExpose *event)
{
GdkPixmap *gdk_pixmap;
GdkPixbuf *gdk_pixbuf,*gdk_pixbuf_tmp;
GdkBitmap *mask;
gint w, h;
gtk_window_get_size (GTK_WINDOW (item), &w, &h);
gdk_pixbuf_tmp = gdk_pixbuf_new_from_file (“./background.png”, NULL);
gdk_pixbuf = gdk_pixbuf_scale_simple (gdk_pixbuf_tmp, w, h, GDK_INTERP_BILINEAR);
g_object_unref (G_OBJECT(gdk_pixbuf_tmp));
gdk_pixbuf_render_pixmap_and_mask (gdk_pixbuf, &gdk_pixmap,&mask, 255);
gdk_window_set_back_pixmap (GTK_WIDGET (item)->window, gdk_pixmap, FALSE);
gtk_widget_shape_combine_mask (GTK_WIDGET (item), mask, 0, 0);
//将widget->window背景设定为 ./background.png
}

或者

C代码

static gboolean
transparent_expose (GtkWidget *widget,
GdkEventExpose *event)
{
GdkPixbuf *gdk_pixbuf, *gdk_pixbuf_tmp;
GdkPixmap *gdk_pixmap;
gdk_pixbuf_tmp = gdk_pixbuf_new_from_file("./background.png", NULL);
gdk_pixbuf = gdk_pixbuf_scale_simple (gdk_pixbuf_tmp, widget->allocation.width, widget->allocation.height , GDK_INTERP_BILINEAR);
gdk_pixbuf_render_pixmap_and_mask ( gdk_pixbuf, &gdk_pixmap,NULL, 127);
g_object_unref(G_OBJECT(gdk_pixbuf_tmp));
g_object_unref(G_OBJECT(gdk_pixbuf));
gdk_draw_drawable (widget->window,
widget->style->black_gc,
gdk_pixmap,
0,
0,
widget->allocation.x,
widget->allocation.y,
widget->allocation.width,
widget->allocation.height );
g_object_unref(G_OBJECT(gdk_pixmap));
return FALSE;
}

C代码

static void
update_background(GtkWidget *widget, gchar *img_file, gint size)
{
GdkPixbuf *style_pixbuf_tmp, *style_pixbuf;
GdkPixmap *style_pixmap;
GtkStyle *style;
// 从文件读取背景图
style_pixbuf_tmp = gdk_pixbuf_new_from_file(img_file, NULL);
gint pic_width, pic_height;
gboolean pic_alpha;
pic_width = gdk_pixbuf_get_width(style_pixbuf_tmp);
pic_height = gdk_pixbuf_get_height(style_pixbuf_tmp);
pic_alpha = gdk_pixbuf_get_has_alpha(style_pixbuf_tmp);
style_pixbuf = gdk_pixbuf_new( GDK_COLORSPACE_RGB, pic_alpha, 8, size, size + 2);
// 将style_pixbuf_tmp复制到style_pixbuf
gdk_pixbuf_scale(style_pixbuf_tmp, style_pixbuf, 0, 0, size, size + 2,
0, -2, (double)size/pic_width, (double)(size + 4)/pic_height,
GDK_INTERP_BILINEAR);
g_object_unref(style_pixbuf_tmp);
// 从style_pixbuf,获取style_pixmap
gdk_pixbuf_render_pixmap_and_mask(style_pixbuf, &style_pixmap, NULL, 0);
g_object_unref(style_pixbuf);
// 获得控件的初始style
style = gtk_style_copy(GTK_WIDGET (widget)->style);
if (style->bg_pixmap[GTK_STATE_NORMAL])
g_object_unref(G_OBJECT(style->bg_pixmap[GTK_STATE_NORMAL]));
// 将style_pixmap画到控件背景上
style->bg_pixmap[GTK_STATE_NORMAL] = g_object_ref(style_pixmap);
gtk_widget_set_style(GTK_WIDGET (widget), style);
g_object_unref(style_pixmap);
}

另外，在GNOME开发手册中，对于expose-event事件中实现图片背景的例子也可以借鉴一下：

http://library.gnome.org/devel/gdk-pixbuf/stable/gdk-pixbuf-scaling.html#gdk-pixbuf-scale

C代码

gboolean
expose_cb (GtkWidget *widget, GdkEventExpose *event, gpointer data)
{
GdkPixbuf *dest;
dest = gdk_pixbuf_new (GDK_COLORSPACE_RGB, FALSE, 8, event->area.width, event->area.height);
gdk_pixbuf_composite_color (pixbuf, dest,
0, 0, event->area.width, event->area.height,
-event->area.x, -event->area.y,
(double) widget->allocation.width / gdk_pixbuf_get_width (pixbuf),
(double) widget->allocation.height / gdk_pixbuf_get_height (pixbuf),
GDK_INTERP_BILINEAR, 255,
event->area.x, event->area.y, 16, 0xaaaaaa, 0x555555);
gdk_draw_pixbuf (widget->window, widget->style->fg_gc[GTK_STATE_NORMAL], dest,
0, 0, event->area.x, event->area.y,
event->area.width, event->area.height,
GDK_RGB_DITHER_NORMAL, event->area.x, event->area.y);
gdk_pixbuf_unref (dest);
return TRUE;
}

函数原型，以及参数的含义：

C代码

void gdk_pixbuf_scale (const GdkPixbuf *src,
GdkPixbuf *dest,
int dest_x,//目的图片的偏移量
int dest_y,
int dest_width,//源图片复制到目的图片的宽度
int dest_height,
double offset_x,//源图片的偏移量
double offset_y,
double scale_x,//要复制的源图片倍数
double scale_y,
GdkInterpType interp_type);

Figure 1. Compositing of pixbufs

src :

a GdkPixbuf

dest :

the GdkPixbuf into which to render the results

dest_x :

the left coordinate for region to render

dest_y :

the top coordinate for region to render

dest_width :

the width of the region to render

dest_height :

the height of the region to render

offset_x :

the offset in the X direction (currently rounded to an integer)

offset_y :

the offset in the Y direction (currently rounded to an integer)

scale_x :

the scale factor in the X direction

scale_y :

the scale factor in the Y direction

interp_type :

the interpolation type for the transformation.

overall_alpha :

overall alpha for source image (0..255)