LibWeb: Add DOMRect and Element.getBoundingClientRect()

This marks our entry into the Web::Geometry namespace, based on the
"Geometry" spec at https://drafts.fxtf.org/geometry/

2 files changed, 72 insertions, 0 deletions

diff --git a/Userland/Libraries/LibWeb/Geometry/DOMRect.h b/Userland/Libraries/LibWeb/Geometry/DOMRect.h
new file mode 100644
index 0000000000..bed9698107
--- /dev/null
+++ b/Userland/Libraries/LibWeb/Geometry/DOMRect.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/RefCounted.h>
+#include <LibGfx/Rect.h>
+#include <LibWeb/Bindings/Wrappable.h>
+#include <LibWeb/Forward.h>
+
+namespace Web::Geometry {
+
+// FIXME: Split this into DOMRectReadOnly and DOMRect
+// https://drafts.fxtf.org/geometry/#DOMRect
+class DOMRect final
+    : public RefCounted<DOMRect>
+    , public Bindings::Wrappable {
+public:
+    using WrapperType = Bindings::DOMRectWrapper;
+
+    static NonnullRefPtr<DOMRect> create_with_global_object(Bindings::WindowObject&, double x = 0, double y = 0, double width = 0, double height = 0)
+    {
+        return DOMRect::create(x, y, width, height);
+    }
+
+    static NonnullRefPtr<DOMRect> create(double x = 0, double y = 0, double width = 0, double height = 0)
+    {
+        return adopt_ref(*new DOMRect(x, y, width, height));
+    }
+
+    static NonnullRefPtr<DOMRect> create(Gfx::FloatRect const& rect)
+    {
+        return adopt_ref(*new DOMRect(rect.x(), rect.y(), rect.width(), rect.height()));
+    }
+
+    double x() const { return m_rect.x(); }
+    double y() const { return m_rect.y(); }
+    double width() const { return m_rect.width(); }
+    double height() const { return m_rect.height(); }
+
+    double top() const { return min(y(), y() + height()); }
+    double right() const { return max(x(), x() + width()); }
+    double bottom() const { return max(y(), y() + height()); }
+    double left() const { return min(x(), x() + width()); }
+
+private:
+    DOMRect(float x, float y, float width, float height)
+        : m_rect(x, y, width, height)
+    {
+    }
+
+    Gfx::FloatRect m_rect;
+};
+}
diff --git a/Userland/Libraries/LibWeb/Geometry/DOMRect.idl b/Userland/Libraries/LibWeb/Geometry/DOMRect.idl
new file mode 100644
index 0000000000..0e0c599f6b
--- /dev/null
+++ b/Userland/Libraries/LibWeb/Geometry/DOMRect.idl
@@ -0,0 +1,15 @@
+interface DOMRect {
+
+    constructor(optional double x = 0, optional double y = 0, optional double width = 0, optional double height = 0);
+
+    readonly attribute double x;
+    readonly attribute double y;
+    readonly attribute double width;
+    readonly attribute double height;
+
+    readonly attribute double top;
+    readonly attribute double right;
+    readonly attribute double bottom;
+    readonly attribute double left;
+
+};