[gtk/matthiasc/for-master: 1/2] gtk-builder-tool: Simplify <style>

[Matthias Clasen <matthiasc src gnome org>]

commit c06c87a61e23a08f33f49327cdc0278f9e930953
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Sep 28 21:11:16 2021 -0400

    gtk-builder-tool: Simplify <style>
    
    Replace <style> elements with simply setting
    the css-classes property. Less custom markup
    is better, and we may want to drop the <style>
    element in the future.
    
    Test included.

 testsuite/tools/simplify-data/test8.expected |  7 ++++++
 testsuite/tools/simplify-data/test8.ui       |  8 +++++++
 tools/gtk-builder-tool-simplify.c            | 32 ++++++++++++++++++++++++++++
 3 files changed, 47 insertions(+)
---
diff --git a/testsuite/tools/simplify-data/test8.expected b/testsuite/tools/simplify-data/test8.expected
new file mode 100644
index 0000000000..1a3dae8d9b
--- /dev/null
+++ b/testsuite/tools/simplify-data/test8.expected
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <object class="GtkLabel">
+    <property name="css-classes">class1
+dim-label</property>
+  </object>
+</interface>
diff --git a/testsuite/tools/simplify-data/test8.ui b/testsuite/tools/simplify-data/test8.ui
new file mode 100644
index 0000000000..3ff5106700
--- /dev/null
+++ b/testsuite/tools/simplify-data/test8.ui
@@ -0,0 +1,8 @@
+<interface>
+  <object class="GtkLabel">
+    <style>
+      <class name="class1"/>
+      <class name="dim-label"/>
+    </style>
+  </object>
+</interface>
diff --git a/tools/gtk-builder-tool-simplify.c b/tools/gtk-builder-tool-simplify.c
index 3eb5a21f78..f82590a447 100644
--- a/tools/gtk-builder-tool-simplify.c
+++ b/tools/gtk-builder-tool-simplify.c
@@ -1910,6 +1910,38 @@ simplify_element (Element      *element,
         warn_missing_property (element, data, class_name, property_name, PROP_KIND_OBJECT);
     }
 
+  if (g_str_equal (element->element_name, "style"))
+    {
+      GString *s;
+
+      s = g_string_new ("");
+
+      for (l = element->children; l; l = l->next)
+        {
+          Element *child = l->data;
+
+          if (g_str_equal (child->element_name, "class"))
+            {
+              if (s->len > 0)
+                g_string_append_c (s, '\n');
+              g_string_append (s, get_attribute_value (child, "name"));
+            }
+        }
+
+      if (s->len > 0)
+        {
+          Element *child = add_element (element->parent, "property");
+          set_attribute_value (child, "name", "css-classes");
+          child->data = g_string_free (s, FALSE);
+        }
+      else
+        {
+          g_string_free (s, TRUE);
+        }
+
+      return TRUE;
+    }
+
   return FALSE;
 }