The image-button style class takes care of it.
<object class="GtkToggleButton" id="search">
<property name="visible">True</property>
<property name="sensitive">False</property>
+ <style>
+ <class name="image-button"/>
+ </style>
<child>
<object class="GtkImage" id="search-icon">
<property name="visible">True</property>
<object class="GtkToggleButton" id="search">
<property name="visible">True</property>
<property name="sensitive">False</property>
+ <style>
+ <class name="image-button"/>
+ </style>
<child>
<object class="GtkImage" id="search-icon">
<property name="visible">True</property>
<object class="GtkToggleButton" id="search">
<property name="visible">True</property>
<property name="sensitive">False</property>
+ <style>
+ <class name="image-button"/>
+ </style>
<child>
<object class="GtkImage" id="search-icon">
<property name="visible">True</property>
<object class="GtkToggleButton" id="search">
<property name="visible">True</property>
<property name="sensitive">False</property>
+ <style>
+ <class name="image-button"/>
+ </style>
<child>
<object class="GtkImage" id="search-icon">
<property name="visible">True</property>