[gnome-builder/wip/gtk4-port] plugins/testui: use IdeTreeExpander

[Christian Hergert <chergert src gnome org>]

commit 25d1373040f38d1a08baca17829cca85d5edfc0a
Author: Christian Hergert <chergert redhat com>
Date:   Thu Jul 7 12:21:20 2022 -0700

    plugins/testui: use IdeTreeExpander
    
    We still need to add menu models, group headers, etc. But this is a start
    on the new widget.

 src/plugins/testui/gbp-testui-panel.ui | 52 ++++++++++++++--------------------
 1 file changed, 22 insertions(+), 30 deletions(-)
---
diff --git a/src/plugins/testui/gbp-testui-panel.ui b/src/plugins/testui/gbp-testui-panel.ui
index 44b55436d..0af94c5f6 100644
--- a/src/plugins/testui/gbp-testui-panel.ui
+++ b/src/plugins/testui/gbp-testui-panel.ui
@@ -22,39 +22,31 @@
 <interface>
   <template class="GtkListItem">
     <property name="child">
-      <object class="GtkTreeExpander" id="expander">
+      <object class="IdeTreeExpander" id="expander">
+        <property name="margin-top">4</property>
+        <property name="margin-bottom">4</property>
+        <property name="margin-start">6</property>
+        <property name="margin-end">6</property>
         <binding name="list-row">
           <lookup name="item">GtkListItem</lookup>
         </binding>
-        <property name="child">
-          <object class="GtkBox">
-            <property name="spacing">6</property>
-            <property name="margin-top">4</property>
-            <property name="margin-bottom">4</property>
-            <property name="margin-start">6</property>
-            <property name="margin-end">6</property>
-            <child>
-              <object class="GtkImage">
-                <binding name="icon-name">
-                  <lookup name="icon-name" type="IdeTest">
-                    <lookup name="item">GtkListItem</lookup>
-                  </lookup>
-                </binding>
-              </object>
-            </child>
-            <child>
-              <object class="GtkLabel">
-                <property name="halign">start</property>
-                <property name="ellipsize">end</property>
-                <binding name="label">
-                  <lookup name="title" type="IdeTest">
-                    <lookup name="item">GtkListItem</lookup>
-                  </lookup>
-                </binding>
-              </object>
-            </child>
-          </object>
-        </property>
+        <binding name="icon-name">
+          <lookup name="icon-name" type="IdeTest">
+            <lookup name="item">GtkListItem</lookup>
+          </lookup>
+        </binding>
+        <binding name="expanded-icon-name">
+          <!-- TODO: add expanded-icon-name -->
+          <lookup name="icon-name" type="IdeTest">
+            <lookup name="item">GtkListItem</lookup>
+          </lookup>
+        </binding>
+        <binding name="title">
+          <!-- TODO: add expanded-icon-name -->
+          <lookup name="title" type="IdeTest">
+            <lookup name="item">GtkListItem</lookup>
+          </lookup>
+        </binding>
       </object>
     </property>
   </template>