Shift-Tab可以聚焦上一个输入字段

Question

我正在使用Glade设计GUI。当我插入GtkEntry字段时，我可以使用Tab键导航到下一个字段（此功能在Glade中“免费”给出）。但是，我似乎无法使用Shift-Tab来聚焦上一个标签条目。

当我有两个按钮时，Tab和Shift-Tab都可以开箱即用。

那么：有没有办法让Shift-Tab将之前的GtkEntry集中在Glade？

Glade代码如下;一个有两个输入字段，一个有两个按钮。

两个条目：

<?xml version="1.0" encoding="UTF-8"?>
<interface>
  <!-- interface-requires gtk+ 3.0 -->
  <object class="GtkWindow" id="window1">
    <property name="can_focus">False</property>
    <child>
      <object class="GtkBox" id="box1">
        <property name="visible">True</property>
        <property name="can_focus">False</property>
        <property name="orientation">vertical</property>
        <property name="homogeneous">True</property>
        <child>
          <object class="GtkEntry" id="entry1">
            <property name="visible">True</property>
            <property name="can_focus">True</property>
            <property name="invisible_char">●</property>
          </object>
          <packing>
            <property name="expand">False</property>
            <property name="fill">True</property>
            <property name="position">0</property>
          </packing>
        </child>
        <child>
          <object class="GtkEntry" id="entry2">
            <property name="visible">True</property>
            <property name="can_focus">True</property>
            <property name="invisible_char">●</property>
          </object>
          <packing>
            <property name="expand">False</property>
            <property name="fill">True</property>
            <property name="position">1</property>
          </packing>
        </child>
      </object>
    </child>
  </object>
</interface>

两个按钮：

<?xml version="1.0" encoding="UTF-8"?>
<interface>
  <!-- interface-requires gtk+ 3.0 -->
  <object class="GtkWindow" id="window1">
    <property name="can_focus">False</property>
    <child>
      <object class="GtkBox" id="box1">
        <property name="visible">True</property>
        <property name="can_focus">False</property>
        <property name="orientation">vertical</property>
        <property name="homogeneous">True</property>
        <child>
          <object class="GtkButton" id="button1">
            <property name="label" translatable="yes">button</property>
            <property name="visible">True</property>
            <property name="can_focus">True</property>
            <property name="receives_default">True</property>
          </object>
          <packing>
            <property name="expand">False</property>
            <property name="fill">True</property>
            <property name="position">0</property>
          </packing>
        </child>
        <child>
          <object class="GtkButton" id="button2">
            <property name="label" translatable="yes">button</property>
            <property name="visible">True</property>
            <property name="can_focus">True</property>
            <property name="receives_default">True</property>
          </object>
          <packing>
            <property name="expand">False</property>
            <property name="fill">True</property>
            <property name="position">1</property>
          </packing>
        </child>
      </object>
    </child>
  </object>
</interface>