[gtk/wip/exalm/nested-scrolling: 1/2] tests: Add a nested scrolling test

[Alexander Mikhaylenko <alexm src gnome org>]

commit 29c49e085dd3075c1f05766a52ebaa31db2918c6
Author: Alexander Mikhaylenko <alexm gnome org>
Date:   Mon Dec 14 18:53:00 2020 +0500

    tests: Add a nested scrolling test

 tests/meson.build           |   1 +
 tests/testnestedscrolling.c | 122 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 123 insertions(+)
---
diff --git a/tests/meson.build b/tests/meson.build
index 51b2311a80..87b18f4916 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -59,6 +59,7 @@ gtk_tests = [
   ['testlockbutton'],
   ['testmenubutton'],
   ['testmountoperation'],
+  ['testnestedscrolling'],
   ['testnotebookdnd'],
   ['testnouiprint'],
   ['testoverlay'],
diff --git a/tests/testnestedscrolling.c b/tests/testnestedscrolling.c
new file mode 100644
index 0000000000..baf8c076a1
--- /dev/null
+++ b/tests/testnestedscrolling.c
@@ -0,0 +1,122 @@
+#include <gtk/gtk.h>
+
+/* This is the function that creates the #GListModel that we need.
+ * GTK list widgets need a #GListModel to display, as models support change
+ * notifications.
+ * Unfortunately various older APIs do not provide list models, so we create
+ * our own.
+ */
+static GListModel *
+create_application_list (void)
+{
+  GListStore *store;
+  GList *apps, *l;
+
+  /* We use a #GListStore here, which is a simple array-like list implementation
+   * for manual management.
+   * List models need to know what type of data they provide, so we need to
+   * provide the type here. As we want to do a list of applications, #GAppInfo
+   * is the object we provide.
+   */
+  store = g_list_store_new (G_TYPE_APP_INFO);
+
+  apps = g_app_info_get_all ();
+
+  for (l = apps; l; l = l->next)
+    g_list_store_append (store, l->data);
+
+  g_list_free_full (apps, g_object_unref);
+
+  return G_LIST_MODEL (store);
+}
+
+static void
+setup_list_item (GtkSignalListItemFactory *factory,
+                 GtkListItem              *list_item)
+{
+  GtkWidget *label = gtk_label_new (NULL);
+
+  gtk_widget_set_margin_top (label, 6);
+  gtk_widget_set_margin_bottom (label, 6);
+
+  gtk_list_item_set_child (list_item, label);
+}
+
+static void
+bind_list_item (GtkSignalListItemFactory *factory,
+                GtkListItem              *list_item)
+{
+  GtkWidget *label;
+  gpointer item;
+  const char *s;
+
+  item = gtk_list_item_get_item (list_item);
+
+  if (item)
+    s = g_app_info_get_name (G_APP_INFO (item));
+  else
+    s = NULL;
+
+  label = gtk_list_item_get_child (list_item);
+  gtk_label_set_text (GTK_LABEL (label), s);
+}
+
+static void
+on_application_activate (GtkApplication *app)
+{
+  GtkWidget *window, *swindow, *box;
+  gint i = 0;
+
+  window = gtk_application_window_new (app);
+  gtk_window_set_default_size (GTK_WINDOW (window), 800, 600);
+
+  swindow = gtk_scrolled_window_new ();
+  gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (swindow), GTK_POLICY_AUTOMATIC, GTK_POLICY_NEVER);
+  gtk_window_set_child (GTK_WINDOW (window), swindow);
+
+  box = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 0);
+  gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (swindow), box);
+
+  for (i = 0; i < 20; i++)
+    {
+      GtkWidget *list, *separator;
+      GtkSelectionModel *model;
+      GtkListItemFactory *factory;
+
+      if (i > 0)
+        {
+          separator = gtk_separator_new (GTK_ORIENTATION_VERTICAL);
+          gtk_box_append (GTK_BOX (box), separator);
+        }
+
+      swindow = gtk_scrolled_window_new ();
+      gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (swindow), GTK_POLICY_NEVER, GTK_POLICY_AUTOMATIC);
+      gtk_box_append (GTK_BOX (box), swindow);
+
+      model = GTK_SELECTION_MODEL (gtk_single_selection_new (create_application_list ()));
+      factory = gtk_signal_list_item_factory_new ();
+      g_signal_connect (factory, "setup", G_CALLBACK (setup_list_item), NULL);
+      g_signal_connect (factory, "bind", G_CALLBACK (bind_list_item), NULL);
+
+      list = gtk_list_view_new (model, factory);
+      gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (swindow), list);
+    }
+
+  gtk_window_present (GTK_WINDOW (window));
+}
+
+int
+main (int argc, char *argv[])
+{
+  GtkApplication *application = gtk_application_new ("org.gtk.test.nestedscrolling",
+                                                     G_APPLICATION_FLAGS_NONE);
+  int result;
+
+  g_signal_connect (application, "activate",
+                    G_CALLBACK (on_application_activate), NULL);
+
+  result = g_application_run (G_APPLICATION (application), argc, argv);
+  g_object_unref (application);
+
+  return result;
+}