如何更改GTK小部件(如堆栈)的属性？

Question

我一直在快速浏览一下GtkStack的GTK 3.10文档.

• https://developer.gnome.org/gtk3/3.10/GtkStack.html

它提到添加到GtkStack的子项被赋予属性"icon-name".

我的问题是 - 如何更改此属性的值.原因 - 我想将GtkStackSwitcher按钮更改为图标而不是文本,但我想对此进行编码 - 而不是使用GktBuilder UI.

如果您查看gtk3-demo- Stack演示和UI文件,您可以看到GtkSwitcher有一个图标.

<?xml version="1.0" encoding="UTF-8"?>
<interface>
  <!-- interface-requires gtk+ 3.6 -->
  <object class="GtkWindow" id="window1">
    <property name="can_focus">False</property>
    <property name="title" translatable="yes">GtkStack</property>
    <child>
      <object class="GtkGrid" id="grid1">
        <property name="visible">True</property>
        <property name="can_focus">False</property>
        <child>
          <object class="GtkStackSwitcher" id="switcher">
            <property name="visible">True</property>
            <property name="stack">stack</property>
            <property name="halign">center</property>
          </object>
          <packing>
            <property name="left_attach">0</property>
            <property name="top_attach">0</property>
            <property name="width">1</property>
            <property name="height">1</property>
          </packing>
        </child>
        <child>
          <object class="GtkStack" id="stack">
            <property name="visible">True</property>
            <property name="can_focus">True</property>
            <property name="transition-type">crossfade</property>
            <child>
              <object class="GtkImage" id="image1">
                <property name="visible">True</property>
                <property name="can_focus">False</property>
                <property name="margin-top">20</property>
                <property name="margin-bottom">20</property>
                <property name="resource">/application/gtk-logo-48.png</property>
              </object>
              <packing>
                <property name="name">page1</property>
                <property name="title" translatable="yes">Page 1</property>
              </packing>
            </child>
            <child>
              <object class="GtkCheckButton" id="checkbutton1">
                <property name="label" translatable="yes">Page 2</property>
                <property name="visible">True</property>
                <property name="can_focus">True</property>
                <property name="receives_default">False</property>
                <property name="xalign">0</property>
                <property name="draw_indicator">True</property>
                <property name="halign">center</property>
                <property name="valign">center</property>
              </object>
              <packing>
                <property name="name">page2</property>
                <property name="title" translatable="yes">Page 2</property>
              </packing>
            </child>
            <child>
              <object class="GtkSpinner" id="spinner1">
                <property name="visible">True</property>
                <property name="can_focus">False</property>
                <property name="halign">center</property>
                <property name="valign">center</property>
                <property name="active">True</property>
              </object>
              <packing>
                <property name="name">page3</property>
                <property name="icon-name">face-laugh-symbolic</property>
              </packing>
            </child>
          </object>
          <packing>
            <property name="left_attach">0</property>
            <property name="top_attach">1</property>
            <property name="width">1</property>
            <property name="height">1</property>
          </packing>
        </child>
      </object>
    </child>
  </object>
</interface>

在Ubuntu 14.04(Gtk 3.10)下使用python3解释器

Python 3.4.0 (default, Apr 11 2014, 13:05:11) 
[GCC 4.8.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from gi.repository import Gtk
>>> stack = Gtk.Stack()
>>> spin = Gtk.Spinner()
>>> stack.add_named(spin, "spin")
>>> stack.show_all()
>>> child = stack.get_visible_child()
>>> child.props.icon_name = "go-previous"
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'gi._gobject.GProps' object has no attribute 'icon_name'
>>> stack.props.icon_name = "go-previous"
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'gi._gobject.GProps' object has no attribute 'icon_name'
>>> 

正如您所看到的 - 我已经将GtkSpinner添加到堆栈对象中 - 我试图访问已添加的子项,然后更改属性"icon-name".

没有快乐.那么我正在做的那个明显的错误是什么？

Answer 1

轻微但重要的区别:icon-name不是a的孩子的"财产" GtkStack,它是"孩子的财产" GtkStack.

不同之处在于"子属性"会影响容器与其中一个子窗口小部件之间的关系,而不仅仅是容器或子窗口小部件.

用这个:

stack.child_set_property(child, 'icon-name', 'go-previous')