Ladybird: Implement the View Source action for the AppKit chrome

This opens a new tab to display the current tab's source as HTML.

Ladybird/AppKit/UI/LadybirdWebView.mm

@@ -9,6 +9,7 @@
 #include <AK/URL.h>
 #include <LibGfx/ImageFormats/PNGWriter.h>
 #include <LibGfx/ShareableBitmap.h>
+#include <LibWebView/SourceHighlighter.h>
 #include <UI/LadybirdWebViewBridge.h>
 
 #import <Application/ApplicationDelegate.h>
@@ -132,6 +133,11 @@ struct HideCursor {
     m_web_view_bridge->set_preferred_color_scheme(color_scheme);
 }
 
+- (void)viewSource
+{
+    m_web_view_bridge->get_source();
+}
+
 #pragma mark - Private methods
 
 - (void)updateViewportRect:(Ladybird::WebViewBridge::ForResize)for_resize
@@ -587,6 +593,16 @@ struct HideCursor {
 
         return Ladybird::ns_rect_to_gfx_rect([[self window] frame]);
     };
+
+    m_web_view_bridge->on_received_source = [self](auto const& url, auto const& source) {
+        auto* delegate = (ApplicationDelegate*)[NSApp delegate];
+        auto html = WebView::highlight_source(url, source);
+
+        [delegate createNewTab:html
+                           url:url
+                       fromTab:[self tab]
+                   activateTab:Web::HTML::ActivateTab::Yes];
+    };
 }
 
 - (Tab*)tab
@@ -721,6 +737,11 @@ static void copy_text_to_clipboard(StringView text)
         [_page_context_menu addItem:[[NSMenuItem alloc] initWithTitle:@"Take Full Screenshot"
                                                                action:@selector(takeFullScreenshot:)
                                                         keyEquivalent:@""]];
+        [_page_context_menu addItem:[NSMenuItem separatorItem]];
+
+        [_page_context_menu addItem:[[NSMenuItem alloc] initWithTitle:@"View Source"
+                                                               action:@selector(viewSource:)
+                                                        keyEquivalent:@""]];
     }
 
     return _page_context_menu;