feat: Astal.Bin

2 files changed, 37 insertions, 0 deletions

diff --git a/lib/astal/gtk4/src/meson.build b/lib/astal/gtk4/src/meson.build
index 58408a6..3bd6a2f 100644
--- a/lib/astal/gtk4/src/meson.build
+++ b/lib/astal/gtk4/src/meson.build
@@ -26,6 +26,7 @@ deps = [
 ]
 
 sources = [config] + files(
+  'widget/bin.vala',
   'widget/box.vala',
   'widget/slider.vala',
   'widget/window.vala',
diff --git a/lib/astal/gtk4/src/widget/bin.vala b/lib/astal/gtk4/src/widget/bin.vala
new file mode 100644
index 0000000..102957b
--- /dev/null
+++ b/lib/astal/gtk4/src/widget/bin.vala
@@ -0,0 +1,36 @@
+/**
+ * A widget with one child.
+ * It is useful for deriving subclasses, since it provides common code needed for handling a single child widget.
+ */
+public class Astal.Bin : Gtk.Widget, Gtk.Buildable {
+    construct { set_layout_manager(new Gtk.BinLayout()); }
+
+    Gtk.Widget _child;
+    public Gtk.Widget? child {
+        get { return _child; }
+        set {
+            if (_child != null) {
+                _child.unparent();
+            }
+
+            if (value != null) {
+                _child = value;
+                value.set_parent(this);
+            }
+        }
+    }
+
+    void add_child(Gtk.Builder builder, Object child, string? type) {
+        if (child is Gtk.Widget) {
+            this.child = child as Gtk.Widget;
+        } else {
+            base.add_child(builder, child, type);
+        }
+    }
+
+    ~Bin() {
+        if (child != null) {
+            child.unparent();
+        }
+    }
+}