Ladybird: Add a menu item to the AppKit chrome to choose a color scheme

This lets the user choose a color scheme which differs from the active
system theme. Upon changing the color scheme, the scheme is broadcast to
all active tabs, and will be used in new tabs.

Ladybird/AppKit/UI/LadybirdWebView.h

@@ -7,6 +7,7 @@
 #pragma once
 
 #include <AK/Forward.h>
+#include <LibWeb/CSS/PreferredColorScheme.h>
 
 #import <System/Cocoa.h>
 
@@ -18,4 +19,6 @@
 - (void)handleScroll;
 - (void)handleVisibility:(BOOL)is_visible;
 
+- (void)setPreferredColorScheme:(Web::CSS::PreferredColorScheme)color_scheme;
+
 @end

Ladybird/AppKit/UI/LadybirdWebView.mm

@@ -85,7 +85,7 @@ struct HideCursor {
 
         auto device_pixel_ratio = [[NSScreen mainScreen] backingScaleFactor];
 
-        m_web_view_bridge = MUST(Ladybird::WebViewBridge::create(move(screen_rects), device_pixel_ratio, [delegate webdriverContentIPCPath]));
+        m_web_view_bridge = MUST(Ladybird::WebViewBridge::create(move(screen_rects), device_pixel_ratio, [delegate webdriverContentIPCPath], [delegate preferredColorScheme]));
         [self setWebViewCallbacks];
 
         auto* area = [[NSTrackingArea alloc] initWithRect:[self bounds]
@@ -122,6 +122,11 @@ struct HideCursor {
     m_web_view_bridge->set_system_visibility_state(is_visible);
 }
 
+- (void)setPreferredColorScheme:(Web::CSS::PreferredColorScheme)color_scheme
+{
+    m_web_view_bridge->set_preferred_color_scheme(color_scheme);
+}
+
 #pragma mark - Private methods
 
 - (void)updateViewportRect:(Ladybird::WebViewBridge::ForResize)for_resize

Ladybird/AppKit/UI/LadybirdWebViewBridge.cpp

@@ -23,14 +23,15 @@ static T scale_for_device(T size, float device_pixel_ratio)
     return size.template to_type<float>().scaled(device_pixel_ratio).template to_type<int>();
 }
 
-ErrorOr<NonnullOwnPtr<WebViewBridge>> WebViewBridge::create(Vector<Gfx::IntRect> screen_rects, float device_pixel_ratio, Optional<StringView> webdriver_content_ipc_path)
+ErrorOr<NonnullOwnPtr<WebViewBridge>> WebViewBridge::create(Vector<Gfx::IntRect> screen_rects, float device_pixel_ratio, Optional<StringView> webdriver_content_ipc_path, Web::CSS::PreferredColorScheme preferred_color_scheme)
 {
-    return adopt_nonnull_own_or_enomem(new (nothrow) WebViewBridge(move(screen_rects), device_pixel_ratio, move(webdriver_content_ipc_path)));
+    return adopt_nonnull_own_or_enomem(new (nothrow) WebViewBridge(move(screen_rects), device_pixel_ratio, move(webdriver_content_ipc_path), preferred_color_scheme));
 }
 
-WebViewBridge::WebViewBridge(Vector<Gfx::IntRect> screen_rects, float device_pixel_ratio, Optional<StringView> webdriver_content_ipc_path)
+WebViewBridge::WebViewBridge(Vector<Gfx::IntRect> screen_rects, float device_pixel_ratio, Optional<StringView> webdriver_content_ipc_path, Web::CSS::PreferredColorScheme preferred_color_scheme)
     : m_screen_rects(move(screen_rects))
     , m_webdriver_content_ipc_path(move(webdriver_content_ipc_path))
+    , m_preferred_color_scheme(preferred_color_scheme)
 {
     m_device_pixel_ratio = device_pixel_ratio;
     m_inverse_device_pixel_ratio = 1.0 / device_pixel_ratio;
@@ -93,6 +94,12 @@ void WebViewBridge::update_palette()
     client().async_update_system_theme(move(theme));
 }
 
+void WebViewBridge::set_preferred_color_scheme(Web::CSS::PreferredColorScheme color_scheme)
+{
+    m_preferred_color_scheme = color_scheme;
+    client().async_set_preferred_color_scheme(color_scheme);
+}
+
 void WebViewBridge::mouse_down_event(Gfx::IntPoint position, GUI::MouseButton button, KeyModifier modifiers)
 {
     client().async_mouse_down(to_content_position(position), to_underlying(button), to_underlying(button), modifiers);
@@ -179,6 +186,7 @@ void WebViewBridge::create_client(WebView::EnableCallgrindProfiling enable_callg
 
     client().async_set_device_pixels_per_css_pixel(m_device_pixel_ratio);
     client().async_update_system_fonts(Gfx::FontDatabase::default_font_query(), Gfx::FontDatabase::fixed_width_font_query(), Gfx::FontDatabase::window_title_font_query());
+    client().async_set_preferred_color_scheme(m_preferred_color_scheme);
     update_palette();
 
     if (!m_screen_rects.is_empty()) {

Ladybird/AppKit/UI/LadybirdWebViewBridge.h

@@ -11,6 +11,7 @@
 #include <LibGfx/Rect.h>
 #include <LibGfx/Size.h>
 #include <LibGfx/StandardCursor.h>
+#include <LibWeb/CSS/PreferredColorScheme.h>
 #include <LibWebView/ViewImplementation.h>
 
 // FIXME: These should not be included outside of Serenity.
@@ -21,7 +22,7 @@ namespace Ladybird {
 
 class WebViewBridge final : public WebView::ViewImplementation {
 public:
-    static ErrorOr<NonnullOwnPtr<WebViewBridge>> create(Vector<Gfx::IntRect> screen_rects, float device_pixel_ratio, Optional<StringView> webdriver_content_ipc_path);
+    static ErrorOr<NonnullOwnPtr<WebViewBridge>> create(Vector<Gfx::IntRect> screen_rects, float device_pixel_ratio, Optional<StringView> webdriver_content_ipc_path, Web::CSS::PreferredColorScheme);
     virtual ~WebViewBridge() override;
 
     float device_pixel_ratio() const { return m_device_pixel_ratio; }
@@ -36,6 +37,7 @@ public:
     void set_viewport_rect(Gfx::IntRect, ForResize = ForResize::No);
 
     void update_palette();
+    void set_preferred_color_scheme(Web::CSS::PreferredColorScheme);
 
     void mouse_down_event(Gfx::IntPoint, GUI::MouseButton, KeyModifier);
     void mouse_up_event(Gfx::IntPoint, GUI::MouseButton, KeyModifier);
@@ -52,7 +54,7 @@ public:
     Optional<Paintable> paintable();
 
 private:
-    WebViewBridge(Vector<Gfx::IntRect> screen_rects, float device_pixel_ratio, Optional<StringView> webdriver_content_ipc_path);
+    WebViewBridge(Vector<Gfx::IntRect> screen_rects, float device_pixel_ratio, Optional<StringView> webdriver_content_ipc_path, Web::CSS::PreferredColorScheme);
 
     virtual void update_zoom() override;
     virtual Gfx::IntRect viewport_rect() const override;
@@ -67,6 +69,7 @@ private:
     float m_inverse_device_pixel_ratio { 1.0 };
 
     Optional<StringView> m_webdriver_content_ipc_path;
+    Web::CSS::PreferredColorScheme m_preferred_color_scheme { Web::CSS::PreferredColorScheme::Auto };
 };
 
 }