1 files changed, 55 insertions, 0 deletions
diff --git a/Libraries/LibGUI/GStackWidget.cpp b/Libraries/LibGUI/GStackWidget.cpp
new file mode 100644
index 0000000000..010cfc6855
--- /dev/null
+++ b/Libraries/LibGUI/GStackWidget.cpp
@@ -0,0 +1,55 @@
+#include <LibGUI/GBoxLayout.h>
+#include <LibGUI/GStackWidget.h>
+
+GStackWidget::GStackWidget(GWidget* parent)
+    : GWidget(parent)
+{
+}
+
+GStackWidget::~GStackWidget()
+{
+}
+
+void GStackWidget::set_active_widget(GWidget* widget)
+{
+    if (widget == m_active_widget)
+        return;
+
+    if (m_active_widget)
+        m_active_widget->set_visible(false);
+    m_active_widget = widget;
+    if (m_active_widget) {
+        m_active_widget->set_relative_rect(rect());
+        m_active_widget->set_visible(true);
+    }
+}
+
+void GStackWidget::resize_event(GResizeEvent& event)
+{
+    if (!m_active_widget)
+        return;
+    m_active_widget->set_relative_rect({ {}, event.size() });
+}
+
+void GStackWidget::child_event(CChildEvent& event)
+{
+    if (!event.child() || !is<GWidget>(*event.child()))
+        return GWidget::child_event(event);
+    auto& child = to<GWidget>(*event.child());
+    if (event.type() == GEvent::ChildAdded) {
+        if (!m_active_widget)
+            set_active_widget(&child);
+        else if (m_active_widget != &child)
+            child.set_visible(false);
+    } else if (event.type() == GEvent::ChildRemoved) {
+        if (m_active_widget == &child) {
+            GWidget* new_active_widget = nullptr;
+            for_each_child_widget([&](auto& new_child) {
+                new_active_widget = &new_child;
+                return IterationDecision::Break;
+            });
+            set_active_widget(new_active_widget);
+        }
+    }
+    GWidget::child_event(event);
+}