tdf#106544 - Merge cells dialog is difficult to understand

Added images underneath the radio buttons, placed at vcl/res/Merge*.svg

Change-Id: Id77b8076f8cd9fb031fe9974d93f35dbe32f63a8
Reviewed-on: https://gerrit.libreoffice.org/52758Reviewed-by: Sophie Gautier <gautier.sophie@gmail.com>
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Heiko Tietze <tietze.heiko@gmail.com>

sc/uiconfig/scalc/ui/mergecellsdialog.ui

 <?xml version="1.0" encoding="UTF-8"?>
-<!-- Generated with glade 3.18.3 -->
+<!-- Generated with glade 3.22.1 -->
 <interface domain="sc">
   <requires lib="gtk+" version="3.18"/>
   <object class="GtkDialog" id="MergeCellsDialog">
@@ -7,6 +7,9 @@
     <property name="border_width">6</property>
     <property name="title" translatable="yes" context="mergecellsdialog|MergeCellsDialog">Merge Cells</property>
     <property name="type_hint">dialog</property>
+    <child>
+      <placeholder/>
+    </child>
     <child internal-child="vbox">
       <object class="GtkBox" id="dialog-vbox1">
         <property name="can_focus">False</property>
@@ -71,12 +74,6 @@
             <property name="position">0</property>
           </packing>
         </child>
-        <child>
-          <object class="GtkBox" id="box1">
-            <property name="visible">True</property>
-            <property name="can_focus">False</property>
-            <property name="orientation">vertical</property>
-            <property name="spacing">6</property>
         <child>
           <object class="GtkLabel" id="label">
             <property name="visible">True</property>
@@ -90,6 +87,10 @@
             <property name="position">0</property>
           </packing>
         </child>
+        <child>
+          <object class="GtkGrid">
+            <property name="visible">True</property>
+            <property name="can_focus">False</property>
             <child>
               <object class="GtkRadioButton" id="move-cells-radio">
                 <property name="label" translatable="yes" context="mergecellsdialog|move-cells-radio">Move the contents of the hidden cells into the first cell</property>
@@ -99,53 +100,92 @@
                 <property name="use_underline">True</property>
                 <property name="xalign">0</property>
                 <property name="draw_indicator">True</property>
-                <property name="group">keep-content-radio</property>
               </object>
               <packing>
-                <property name="expand">False</property>
-                <property name="fill">True</property>
-                <property name="position">1</property>
+                <property name="left_attach">0</property>
+                <property name="top_attach">0</property>
               </packing>
             </child>
             <child>
-              <object class="GtkRadioButton" id="keep-content-radio">
-                <property name="label" translatable="yes" context="mergecellsdialog|keep-content-radio">Keep the contents of the hidden cells</property>
+              <object class="GtkRadioButton" id="empty-cells-radio">
+                <property name="label" translatable="yes" context="mergecellsdialog|empty-cells-radio">Empty the contents of the hidden cells</property>
                 <property name="visible">True</property>
                 <property name="can_focus">True</property>
                 <property name="receives_default">False</property>
                 <property name="use_underline">True</property>
                 <property name="xalign">0</property>
-                <property name="active">True</property>
                 <property name="draw_indicator">True</property>
               </object>
               <packing>
-                <property name="expand">False</property>
-                <property name="fill">True</property>
-                <property name="position">2</property>
+                <property name="left_attach">0</property>
+                <property name="top_attach">4</property>
               </packing>
             </child>
             <child>
-              <object class="GtkRadioButton" id="empty-cells-radio">
-                <property name="label" translatable="yes" context="mergecellsdialog|empty-cells-radio">Empty the contents of the hidden cells</property>
+              <object class="GtkRadioButton" id="keep-content-radio">
+                <property name="label" translatable="yes" context="mergecellsdialog|keep-content-radio">Keep the contents of the hidden cells</property>
                 <property name="visible">True</property>
                 <property name="can_focus">True</property>
                 <property name="receives_default">False</property>
                 <property name="use_underline">True</property>
                 <property name="xalign">0</property>
+                <property name="active">True</property>
                 <property name="draw_indicator">True</property>
-                <property name="group">keep-content-radio</property>
               </object>
               <packing>
-                <property name="expand">False</property>
-                <property name="fill">True</property>
-                <property name="position">3</property>
+                <property name="left_attach">0</property>
+                <property name="top_attach">2</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkImage" id="imMergeFirstCell">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="halign">start</property>
+                <property name="margin_left">24</property>
+                <property name="margin_bottom">6</property>
+                <property name="hexpand">False</property>
+                <property name="pixbuf">vcl/res/MergeFirstCell.svg</property>
+              </object>
+              <packing>
+                <property name="left_attach">0</property>
+                <property name="top_attach">1</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkImage" id="imMergeKeepHidden">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="halign">start</property>
+                <property name="margin_left">24</property>
+                <property name="margin_bottom">6</property>
+                <property name="hexpand">True</property>
+                <property name="pixbuf">vcl/res/MergeKeepHidden.svg</property>
+              </object>
+              <packing>
+                <property name="left_attach">0</property>
+                <property name="top_attach">3</property>
+              </packing>
+            </child>
+            <child>
+              <object class="GtkImage" id="imMergeEmptyHidden">
+                <property name="visible">True</property>
+                <property name="can_focus">False</property>
+                <property name="halign">start</property>
+                <property name="margin_left">24</property>
+                <property name="hexpand">True</property>
+                <property name="pixbuf">vcl/res/MergeEmptyHidden.svg</property>
+              </object>
+              <packing>
+                <property name="left_attach">0</property>
+                <property name="top_attach">5</property>
               </packing>
             </child>
           </object>
           <packing>
             <property name="expand">False</property>
             <property name="fill">True</property>
-            <property name="position">1</property>
+            <property name="position">2</property>
           </packing>
         </child>
       </object>