LibWeb: Implemented shadows support for CanvasRenderingContext2D

Author: https://github.com/uysalibov 🔰
Commit: 34f7bf979d
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/1848
Reviewed-by: https://github.com/kalenikaliaksandr ✅

Userland/Libraries/LibWeb/HTML/Canvas/CanvasShadowStyles.h

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2024, İbrahim UYSAL <uysalibov@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/String.h>
+#include <LibWeb/CSS/Parser/Parser.h>
+#include <LibWeb/HTML/Canvas/CanvasState.h>
+#include <LibWeb/HTML/CanvasGradient.h>
+#include <LibWeb/HTML/CanvasPattern.h>
+
+namespace Web::HTML {
+
+// https://html.spec.whatwg.org/multipage/canvas.html#canvasshadowstyles
+template<typename IncludingClass>
+class CanvasShadowStyles {
+public:
+    ~CanvasShadowStyles() = default;
+
+    virtual float shadow_offset_x() const = 0;
+    virtual void set_shadow_offset_x(float offsetX) = 0;
+
+    virtual float shadow_offset_y() const = 0;
+    virtual void set_shadow_offset_y(float offsetY) = 0;
+
+    virtual String shadow_color() const = 0;
+    virtual void set_shadow_color(String color) = 0;
+
+protected:
+    CanvasShadowStyles() = default;
+
+private:
+    CanvasState::DrawingState& my_drawing_state() { return reinterpret_cast<IncludingClass&>(*this).drawing_state(); }
+    CanvasState::DrawingState const& my_drawing_state() const { return reinterpret_cast<IncludingClass const&>(*this).drawing_state(); }
+};
+
+}

Userland/Libraries/LibWeb/HTML/Canvas/CanvasShadowStyles.idl

@@ -1,8 +1,8 @@
 // https://html.spec.whatwg.org/multipage/canvas.html#canvasshadowstyles
 interface mixin CanvasShadowStyles {
     // shadows
-    [FIXME] attribute unrestricted double shadowOffsetX; // (default 0)
-    [FIXME] attribute unrestricted double shadowOffsetY; // (default 0)
+    attribute unrestricted double shadowOffsetX; // (default 0)
+    attribute unrestricted double shadowOffsetY; // (default 0)
     [FIXME] attribute unrestricted double shadowBlur; // (default 0)
-    [FIXME] attribute DOMString shadowColor; // (default transparent black)
+    attribute DOMString shadowColor; // (default transparent black)
 };

Userland/Libraries/LibWeb/HTML/Canvas/CanvasState.h

@@ -80,6 +80,9 @@ public:
         Gfx::AffineTransform transform;
         FillOrStrokeStyle fill_style { Gfx::Color::Black };
         FillOrStrokeStyle stroke_style { Gfx::Color::Black };
+        float shadow_offset_x { 0.0f };
+        float shadow_offset_y { 0.0f };
+        Gfx::Color shadow_color { Gfx::Color::Transparent };
         float line_width { 1 };
         Vector<double> dash_list;
         bool image_smoothing_enabled { true };