From 58ce2dd08806fb998d8705868314d25753674f30 Mon Sep 17 00:00:00 2001
From: DerpyCrabs <derpycrabs@gmail.com>
Date: Sat, 12 Feb 2022 16:48:00 +0300
Subject: [PATCH] LibWeb: Add stub implementation for Element's getClientRects

getClientRects supposed to return a list of bounding DOMRect
for each box fragment of Element's layout, but most elements have
only one box fragment, so implementing it with getBoundingClientRect
is useful.
---
 Userland/Libraries/LibWeb/DOM/Element.cpp | 25 +++++++++++++++++++++++
 Userland/Libraries/LibWeb/DOM/Element.h   |  1 +
 Userland/Libraries/LibWeb/DOM/Element.idl |  1 +
 3 files changed, 27 insertions(+)

diff --git a/Userland/Libraries/LibWeb/DOM/Element.cpp b/Userland/Libraries/LibWeb/DOM/Element.cpp
index f21f5f4661..30e3fb3437 100644
--- a/Userland/Libraries/LibWeb/DOM/Element.cpp
+++ b/Userland/Libraries/LibWeb/DOM/Element.cpp
@@ -20,6 +20,7 @@
 #include <LibWeb/DOM/Text.h>
 #include <LibWeb/DOMParsing/InnerHTML.h>
 #include <LibWeb/Geometry/DOMRect.h>
+#include <LibWeb/Geometry/DOMRectList.h>
 #include <LibWeb/HTML/BrowsingContext.h>
 #include <LibWeb/HTML/EventLoop/EventLoop.h>
 #include <LibWeb/HTML/Parser/HTMLParser.h>
@@ -447,6 +448,30 @@ NonnullRefPtr<Geometry::DOMRect> Element::get_bounding_client_rect() const
     return Geometry::DOMRect::create(box.absolute_rect().translated(-viewport_offset.x(), -viewport_offset.y()));
 }
 
+// https://drafts.csswg.org/cssom-view/#dom-element-getclientrects
+NonnullRefPtr<Geometry::DOMRectList> Element::get_client_rects() const
+{
+    NonnullRefPtrVector<Geometry::DOMRect> rects;
+
+    // 1. If the element on which it was invoked does not have an associated layout box return an empty DOMRectList object and stop this algorithm.
+    if (!layout_node() || !layout_node()->is_box())
+        return Geometry::DOMRectList::create(move(rects));
+
+    // FIXME: 2. If the element has an associated SVG layout box return a DOMRectList object containing a single DOMRect object that describes
+    // the bounding box of the element as defined by the SVG specification, applying the transforms that apply to the element and its ancestors.
+
+    // FIXME: 3. Return a DOMRectList object containing DOMRect objects in content order, one for each box fragment,
+    // describing its border area (including those with a height or width of zero) with the following constraints:
+    // - Apply the transforms that apply to the element and its ancestors.
+    // - If the element on which the method was invoked has a computed value for the display property of table
+    // or inline-table include both the table box and the caption box, if any, but not the anonymous container box.
+    // - Replace each anonymous block box with its child box(es) and repeat this until no anonymous block boxes are left in the final list.
+
+    auto bounding_rect = get_bounding_client_rect();
+    rects.append(bounding_rect);
+    return Geometry::DOMRectList::create(move(rects));
+}
+
 int Element::client_top() const
 {
     if (!layout_node() || !layout_node()->is_box())
diff --git a/Userland/Libraries/LibWeb/DOM/Element.h b/Userland/Libraries/LibWeb/DOM/Element.h
index 4c1b1a6e04..4242c6d5eb 100644
--- a/Userland/Libraries/LibWeb/DOM/Element.h
+++ b/Userland/Libraries/LibWeb/DOM/Element.h
@@ -125,6 +125,7 @@ public:
     bool serializes_as_void() const;
 
     NonnullRefPtr<Geometry::DOMRect> get_bounding_client_rect() const;
+    NonnullRefPtr<Geometry::DOMRectList> get_client_rects() const;
 
     virtual RefPtr<Layout::Node> create_layout_node(NonnullRefPtr<CSS::StyleProperties>);
 
diff --git a/Userland/Libraries/LibWeb/DOM/Element.idl b/Userland/Libraries/LibWeb/DOM/Element.idl
index e11a33dcd6..3cf0b0f255 100644
--- a/Userland/Libraries/LibWeb/DOM/Element.idl
+++ b/Userland/Libraries/LibWeb/DOM/Element.idl
@@ -49,6 +49,7 @@ interface Element : Node {
     [SameObject] readonly attribute HTMLCollection children;
 
     DOMRect getBoundingClientRect();
+    DOMRectList getClientRects();
 
     readonly attribute long clientTop;
     readonly attribute long clientLeft;