Remove text from auto-color button. A simple symbol is enough.

doxygen/Doxyconfig

@@ -234,7 +234,7 @@ SEPARATE_MEMBER_PAGES  = NO
 # uses this value to replace tabs by spaces in code fragments.
 # Minimum value: 1, maximum value: 16, default value: 4.
 
-TAB_SIZE               = 4
+TAB_SIZE               = 8
 
 # This tag can be used to specify a number of aliases that act as commands in
 # the documentation. An alias has the form:

glade/main.glade

@@ -2,15 +2,30 @@
 <!-- Generated with glade 3.22.1 -->
 <interface>
   <requires lib="gtk+" version="3.20"/>
-  <object class="GtkImage" id="image1">
+  <object class="GtkImage" id="color-img">
     <property name="visible">True</property>
     <property name="can_focus">False</property>
-    <property name="stock">gtk-go-up</property>
+    <property name="stock">gtk-select-color</property>
   </object>
-  <object class="GtkImage" id="image2">
+  <object class="GtkImage" id="load-mapping-img">
     <property name="visible">True</property>
     <property name="can_focus">False</property>
-    <property name="stock">gtk-go-down</property>
+    <property name="stock">gtk-open</property>
+  </object>
+  <object class="GtkImage" id="save-mapping-img">
+    <property name="visible">True</property>
+    <property name="can_focus">False</property>
+    <property name="stock">gtk-save-as</property>
+  </object>
+  <object class="GtkImage" id="sort-down-img">
+    <property name="visible">True</property>
+    <property name="can_focus">False</property>
+    <property name="stock">gtk-sort-ascending</property>
+  </object>
+  <object class="GtkImage" id="sort-up-img">
+    <property name="visible">True</property>
+    <property name="can_focus">False</property>
+    <property name="stock">gtk-sort-descending</property>
   </object>
   <object class="GtkWindow" id="main-window">
     <property name="height_request">250</property>
@@ -43,6 +58,8 @@
             <property name="sensitive">False</property>
             <property name="can_focus">True</property>
             <property name="receives_default">True</property>
+            <property name="image">load-mapping-img</property>
+            <property name="always_show_image">True</property>
             <style>
               <class name="suggested-action"/>
             </style>
@@ -58,6 +75,8 @@
             <property name="sensitive">False</property>
             <property name="can_focus">True</property>
             <property name="receives_default">True</property>
+            <property name="image">save-mapping-img</property>
+            <property name="always_show_image">True</property>
             <style>
               <class name="suggested-action"/>
             </style>
@@ -155,7 +174,7 @@
                     <property name="visible">True</property>
                     <property name="can_focus">True</property>
                     <property name="receives_default">True</property>
-                    <property name="image">image1</property>
+                    <property name="image">sort-up-img</property>
                     <property name="always_show_image">True</property>
                   </object>
                   <packing>
@@ -169,7 +188,7 @@
                     <property name="visible">True</property>
                     <property name="can_focus">True</property>
                     <property name="receives_default">True</property>
-                    <property name="image">image2</property>
+                    <property name="image">sort-down-img</property>
                     <property name="always_show_image">True</property>
                   </object>
                   <packing>
@@ -178,6 +197,20 @@
                     <property name="position">1</property>
                   </packing>
                 </child>
+                <child>
+                  <object class="GtkButton" id="auto-color-button">
+                    <property name="visible">True</property>
+                    <property name="can_focus">True</property>
+                    <property name="receives_default">True</property>
+                    <property name="image">color-img</property>
+                    <property name="always_show_image">True</property>
+                  </object>
+                  <packing>
+                    <property name="expand">False</property>
+                    <property name="fill">True</property>
+                    <property name="position">2</property>
+                  </packing>
+                </child>
               </object>
               <packing>
                 <property name="expand">False</property>