control activity/category sizes

data/edit_activity.ui

@@ -156,6 +156,7 @@
           <object class="GtkBox">
             <property name="visible">True</property>
             <property name="can_focus">False</property>
+            <property name="spacing">4</property>
             <property name="homogeneous">True</property>
             <child>
               <object class="GtkBox" id="start box">
@@ -247,10 +248,9 @@
           </packing>
         </child>
         <child>
-          <object class="GtkBox">
+          <object class="GtkPaned">
             <property name="visible">True</property>
-            <property name="can_focus">False</property>
-            <property name="homogeneous">True</property>
+            <property name="can_focus">True</property>
             <child>
               <object class="GtkBox" id="activity box">
                 <property name="visible">True</property>
@@ -279,22 +279,22 @@
                     <property name="can_focus">True</property>
                   </object>
                   <packing>
-                    <property name="expand">False</property>
+                    <property name="expand">True</property>
                     <property name="fill">True</property>
                     <property name="position">1</property>
                   </packing>
                 </child>
               </object>
               <packing>
-                <property name="expand">True</property>
-                <property name="fill">True</property>
-                <property name="position">0</property>
+                <property name="resize">True</property>
+                <property name="shrink">False</property>
               </packing>
             </child>
             <child>
               <object class="GtkBox" id="category box">
                 <property name="visible">True</property>
                 <property name="can_focus">False</property>
+                <property name="margin_left">4</property>
                 <property name="orientation">vertical</property>
                 <child>
                   <object class="GtkLabel">
@@ -319,16 +319,15 @@
                     <property name="can_focus">True</property>
                   </object>
                   <packing>
-                    <property name="expand">False</property>
+                    <property name="expand">True</property>
                     <property name="fill">True</property>
                     <property name="position">1</property>
                   </packing>
                 </child>
               </object>
               <packing>
-                <property name="expand">False</property>
-                <property name="fill">True</property>
-                <property name="position">2</property>
+                <property name="resize">True</property>
+                <property name="shrink">False</property>
               </packing>
             </child>
           </object>