utils: Add util function for selection widgetry

Will be used by the week grid

src/utils/gcal-gui-utils.c

@@ -0,0 +1,32 @@
+/*
+ * gcal-gui-utils.c
+ *
+ * Copyright 2025 Georges Basile Stavracas Neto <georges.stavracas@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "gcal-gui-utils.h"
+
+#include <adwaita.h>
+
+GtkWidget*
+gcal_create_selection_widget (void)
+{
+  return g_object_new (ADW_TYPE_BIN,
+                       "css-name", "selection",
+                       NULL);
+}

src/utils/gcal-gui-utils.h

@@ -0,0 +1,30 @@
+/*
+ * gcal-gui-utils.h
+ *
+ * Copyright 2025 Georges Basile Stavracas Neto <georges.stavracas@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include <gtk/gtk.h>
+
+G_BEGIN_DECLS
+
+GtkWidget* gcal_create_selection_widget (void);
+
+G_END_DECLS

src/utils/meson.build

@@ -2,6 +2,7 @@ calendar_incs +=  include_directories('.')
 
 sources += files(
   'gcal-date-time-utils.c',
+  'gcal-gui-utils.c',
   'gcal-source-discoverer.c',
   'gcal-utils.c',
 )