1 files changed, 110 insertions, 0 deletions
diff --git a/src/gs-layout-manager.c b/src/gs-layout-manager.c
new file mode 100644
index 0000000..37fcf49
--- /dev/null
+++ b/src/gs-layout-manager.c
@@ -0,0 +1,110 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
+ * vi:set noexpandtab tabstop=8 shiftwidth=8:
+ *
+ * Copyright (C) 2021 Endless OS Foundation LLC
+ *
+ * Author: Georges Basile Stavracas Neto <georges.stavracas@gmail.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include "config.h"
+
+#include "gs-layout-manager.h"
+
+/*
+ * The GsLayoutManager is a copy of the GtkBoxLayout, only
+ * declared as a derivable class, to avoid code duplication.
+ */
+
+G_DEFINE_TYPE (GsLayoutManager, gs_layout_manager, GTK_TYPE_LAYOUT_MANAGER)
+
+static void
+gs_layout_manager_measure (GtkLayoutManager *layout_manager,
+			   GtkWidget        *widget,
+			   GtkOrientation    orientation,
+			   gint              for_size,
+			   gint             *minimum,
+			   gint             *natural,
+			   gint             *minimum_baseline,
+			   gint             *natural_baseline)
+{
+	GtkWidget *child;
+	gint min = 0;
+	gint nat = 0;
+
+	for (child = gtk_widget_get_first_child (widget);
+	     child != NULL;
+	     child = gtk_widget_get_next_sibling (child)) {
+		gint child_min_baseline = -1;
+		gint child_nat_baseline = -1;
+		gint child_min = 0;
+		gint child_nat = 0;
+
+		if (!gtk_widget_should_layout (child))
+			continue;
+
+		gtk_widget_measure (child, orientation,
+				    for_size,
+				    &child_min, &child_nat,
+				    &child_min_baseline,
+				    &child_nat_baseline);
+
+		min = MAX (min, child_min);
+		nat = MAX (nat, child_nat);
+
+		if (child_min_baseline > -1)
+			*minimum_baseline = MAX (*minimum_baseline, child_min_baseline);
+		if (child_nat_baseline > -1)
+		    *natural_baseline = MAX (*natural_baseline, child_nat_baseline);
+	}
+
+	*minimum = min;
+	*natural = nat;
+}
+
+static void
+gs_layout_manager_allocate (GtkLayoutManager *layout_manager,
+			    GtkWidget        *widget,
+			    gint              width,
+			    gint              height,
+			    gint              baseline)
+{
+	GtkWidget *child;
+
+	for (child = gtk_widget_get_first_child (widget);
+	     child != NULL;
+	     child = gtk_widget_get_next_sibling (child)) {
+		if (child && gtk_widget_should_layout (child))
+			gtk_widget_allocate (child, width, height, baseline, NULL);
+	}
+}
+
+static void
+gs_layout_manager_class_init (GsLayoutManagerClass *klass)
+{
+	GtkLayoutManagerClass *layout_manager_class = GTK_LAYOUT_MANAGER_CLASS (klass);
+
+	layout_manager_class->measure = gs_layout_manager_measure;
+	layout_manager_class->allocate = gs_layout_manager_allocate;
+}
+
+static void
+gs_layout_manager_init (GsLayoutManager *self)
+{
+}
+
+/**
+ * gs_layout_manager_new:
+ *
+ * Create a new #GsLayoutManager.
+ *
+ * Returns: (transfer full): a new #GsLayoutManager
+ *
+ * Since: 43
+ **/
+GtkLayoutManager *
+gs_layout_manager_new (void)
+{
+	return g_object_new (GS_TYPE_LAYOUT_MANAGER, NULL);
+}