Ladybird: Add context menu items to the AppKit chrome to inspect nodes

Ladybird/AppKit/UI/Inspector.h

@@ -16,6 +16,7 @@
 - (instancetype)init:(Tab*)tab;
 
 - (void)inspect;
+- (void)inspectHoveredElement;
 - (void)reset;
 
 @end

Ladybird/AppKit/UI/Inspector.mm

@@ -6,6 +6,7 @@
 
 #include <AK/DeprecatedString.h>
 #include <AK/HashMap.h>
+#include <AK/Optional.h>
 #include <AK/Traits.h>
 #include <LibWeb/CSS/Selector.h>
 #include <LibWebView/ViewImplementation.h>
@@ -43,7 +44,10 @@ struct Selection {
 
 @interface Inspector () <NSOutlineViewDataSource, NSOutlineViewDelegate, NSTableViewDataSource>
 {
+    BOOL m_dom_tree_loaded;
+
     Selection m_selection;
+    Optional<i32> m_pending_selection;
 
     HashMap<NSDictionary*, NSDictionary*> m_dom_node_to_parent_map;
     HashMap<i32, NSDictionary*> m_node_id_to_dom_node_map;
@@ -118,6 +122,11 @@ struct Selection {
                 [strong_self.dom_tree_outline_view sizeToFit];
 
                 [strong_self prepareDOMNodeMaps:strong_self.dom_tree parentNode:nil];
+                strong_self->m_dom_tree_loaded = YES;
+
+                if (strong_self->m_pending_selection.has_value()) {
+                    [strong_self inspectDOMNodeID:strong_self->m_pending_selection.release_value()];
+                }
             } else {
                 strong_self.dom_tree = @{};
             }
@@ -149,9 +158,25 @@ struct Selection {
     web_view.inspect_dom_tree();
 }
 
+- (void)inspectHoveredElement
+{
+    auto& web_view = [[self.tab web_view] view];
+    auto node_id = web_view.get_hovered_node_id();
+
+    if (!m_dom_tree_loaded) {
+        m_pending_selection = node_id;
+        return;
+    }
+
+    [self inspectDOMNodeID:node_id];
+}
+
 - (void)reset
 {
+    m_dom_tree_loaded = NO;
+
     m_selection = {};
+    m_pending_selection = {};
 
     m_dom_node_to_parent_map = {};
     m_node_id_to_dom_node_map = {};
@@ -261,6 +286,34 @@ struct Selection {
     }
 }
 
+- (void)inspectDOMNodeID:(i32)node_id
+{
+    auto dom_node = m_node_id_to_dom_node_map.get(node_id);
+    if (!dom_node.has_value()) {
+        return;
+    }
+
+    [self expandDOMNode:*dom_node];
+
+    if (auto row = [self.dom_tree_outline_view rowForItem:*dom_node]; row != -1) {
+        auto index = [NSIndexSet indexSetWithIndex:row];
+        [self.dom_tree_outline_view selectRowIndexes:index byExtendingSelection:NO];
+    }
+
+    [self setSelection: { node_id }];
+}
+
+- (void)expandDOMNode:(NSDictionary*)dom_node
+{
+    // We can't expand an item unless its parent is also already expanded, so walk up the tree to
+    // expand all ancestors.
+    if (auto parent_node = m_dom_node_to_parent_map.get(dom_node); parent_node.has_value()) {
+        [self expandDOMNode:*parent_node];
+    }
+
+    [self.dom_tree_outline_view expandItem:dom_node];
+}
+
 - (void)setSelection:(Selection)selection
 {
     if (selection == m_selection)

Ladybird/AppKit/UI/LadybirdWebView.mm

@@ -722,6 +722,9 @@ static void copy_text_to_clipboard(StringView text)
         [_page_context_menu addItem:[[NSMenuItem alloc] initWithTitle:@"View Source"
                                                                action:@selector(viewSource:)
                                                         keyEquivalent:@""]];
+        [_page_context_menu addItem:[[NSMenuItem alloc] initWithTitle:@"Inspect Element"
+                                                               action:@selector(inspectElement:)
+                                                        keyEquivalent:@""]];
     }
 
     return _page_context_menu;
@@ -743,6 +746,11 @@ static void copy_text_to_clipboard(StringView text)
         [_link_context_menu addItem:[[NSMenuItem alloc] initWithTitle:@"Copy URL"
                                                                action:@selector(copyLink:)
                                                         keyEquivalent:@""]];
+        [_link_context_menu addItem:[NSMenuItem separatorItem]];
+
+        [_link_context_menu addItem:[[NSMenuItem alloc] initWithTitle:@"Inspect Element"
+                                                               action:@selector(inspectElement:)
+                                                        keyEquivalent:@""]];
     }
 
     return _link_context_menu;
@@ -767,6 +775,11 @@ static void copy_text_to_clipboard(StringView text)
         [_image_context_menu addItem:[[NSMenuItem alloc] initWithTitle:@"Copy Image URL"
                                                                 action:@selector(copyLink:)
                                                          keyEquivalent:@""]];
+        [_image_context_menu addItem:[NSMenuItem separatorItem]];
+
+        [_image_context_menu addItem:[[NSMenuItem alloc] initWithTitle:@"Inspect Element"
+                                                                action:@selector(inspectElement:)
+                                                         keyEquivalent:@""]];
     }
 
     return _image_context_menu;
@@ -814,6 +827,11 @@ static void copy_text_to_clipboard(StringView text)
         [_audio_context_menu addItem:[[NSMenuItem alloc] initWithTitle:@"Copy Audio URL"
                                                                 action:@selector(copyLink:)
                                                          keyEquivalent:@""]];
+        [_audio_context_menu addItem:[NSMenuItem separatorItem]];
+
+        [_audio_context_menu addItem:[[NSMenuItem alloc] initWithTitle:@"Inspect Element"
+                                                                action:@selector(inspectElement:)
+                                                         keyEquivalent:@""]];
     }
 
     return _audio_context_menu;
@@ -861,6 +879,11 @@ static void copy_text_to_clipboard(StringView text)
         [_video_context_menu addItem:[[NSMenuItem alloc] initWithTitle:@"Copy Video URL"
                                                                 action:@selector(copyLink:)
                                                          keyEquivalent:@""]];
+        [_video_context_menu addItem:[NSMenuItem separatorItem]];
+
+        [_video_context_menu addItem:[[NSMenuItem alloc] initWithTitle:@"Inspect Element"
+                                                                action:@selector(inspectElement:)
+                                                         keyEquivalent:@""]];
     }
 
     return _video_context_menu;

Ladybird/AppKit/UI/Tab.mm

@@ -149,6 +149,14 @@ static constexpr CGFloat const WINDOW_HEIGHT = 800;
     self.inspector_controller = nil;
 }
 
+- (void)inspectElement:(id)sender
+{
+    [self openInspector:sender];
+
+    auto* inspector = (Inspector*)[self.inspector_controller window];
+    [inspector inspectHoveredElement];
+}
+
 #pragma mark - Private methods
 
 - (TabController*)tabController