LibWebView: Make DOMTreeModel usable outside of SerenityOS

Two issues made this class unusable on other platforms:
- Hardcoded /res paths to icons
- It required a GUI::TreeView for palette access

This patch simply patches out those features on non-Serenity systemsf
for now.

Userland/Libraries/LibWebView/DOMTreeModel.cpp

@@ -14,13 +14,16 @@
 
 namespace WebView {
 
-DOMTreeModel::DOMTreeModel(JsonObject dom_tree, GUI::TreeView& tree_view)
+DOMTreeModel::DOMTreeModel(JsonObject dom_tree, GUI::TreeView* tree_view)
     : m_tree_view(tree_view)
     , m_dom_tree(move(dom_tree))
 {
+    // FIXME: Get these from the outside somehow instead of hard-coding paths here.
+#ifdef __serenity__
     m_document_icon.set_bitmap_for_size(16, Gfx::Bitmap::try_load_from_file("/res/icons/16x16/filetype-html.png"sv).release_value_but_fixme_should_propagate_errors());
     m_element_icon.set_bitmap_for_size(16, Gfx::Bitmap::try_load_from_file("/res/icons/16x16/inspector-object.png"sv).release_value_but_fixme_should_propagate_errors());
     m_text_icon.set_bitmap_for_size(16, Gfx::Bitmap::try_load_from_file("/res/icons/16x16/filetype-unknown.png"sv).release_value_but_fixme_should_propagate_errors());
+#endif
 
     map_dom_nodes_to_parent(nullptr, &m_dom_tree);
 }
@@ -119,18 +122,23 @@ GUI::Variant DOMTreeModel::data(const GUI::ModelIndex& index, GUI::ModelRole rol
     auto node_name = node.get("name"sv).as_string();
     auto type = node.get("type"sv).as_string_or("unknown"sv);
 
+    // FIXME: This FIXME can go away when we fix the one below.
+#ifdef __serenity__
     if (role == GUI::ModelRole::ForegroundColor) {
         // FIXME: Allow models to return a foreground color *role*.
         //        Then we won't need to have a GUI::TreeView& member anymore.
         if (type == "comment"sv)
-            return m_tree_view.palette().syntax_comment();
+            return m_tree_view->palette().syntax_comment();
         if (type == "pseudo-element"sv)
-            return m_tree_view.palette().syntax_type();
+            return m_tree_view->palette().syntax_type();
         if (!node.get("visible"sv).to_bool(true))
-            return m_tree_view.palette().syntax_comment();
+            return m_tree_view->palette().syntax_comment();
         return {};
     }
+#endif
 
+    // FIXME: This FIXME can go away when the icons are provided from the outside (see constructor).
+#ifdef __serenity__
     if (role == GUI::ModelRole::Icon) {
         if (type == "document")
             return m_document_icon;
@@ -139,6 +147,8 @@ GUI::Variant DOMTreeModel::data(const GUI::ModelIndex& index, GUI::ModelRole rol
         // FIXME: More node type icons?
         return m_text_icon;
     }
+#endif
+
     if (role == GUI::ModelRole::Display) {
         if (type == "text")
             return with_whitespace_collapsed(node.get("text"sv).as_string());

Userland/Libraries/LibWebView/DOMTreeModel.h

@@ -20,7 +20,13 @@ public:
     static NonnullRefPtr<DOMTreeModel> create(StringView dom_tree, GUI::TreeView& tree_view)
     {
         auto json_or_error = JsonValue::from_string(dom_tree).release_value_but_fixme_should_propagate_errors();
-        return adopt_ref(*new DOMTreeModel(json_or_error.as_object(), tree_view));
+        return adopt_ref(*new DOMTreeModel(json_or_error.as_object(), &tree_view));
+    }
+
+    static NonnullRefPtr<DOMTreeModel> create(StringView dom_tree)
+    {
+        auto json_or_error = JsonValue::from_string(dom_tree).release_value_but_fixme_should_propagate_errors();
+        return adopt_ref(*new DOMTreeModel(json_or_error.as_object(), nullptr));
     }
 
     virtual ~DOMTreeModel() override;
@@ -34,7 +40,7 @@ public:
     GUI::ModelIndex index_for_node(i32 node_id, Optional<Web::CSS::Selector::PseudoElement> pseudo_element) const;
 
 private:
-    DOMTreeModel(JsonObject, GUI::TreeView&);
+    DOMTreeModel(JsonObject, GUI::TreeView*);
 
     ALWAYS_INLINE JsonObject const* get_parent(JsonObject const& o) const
     {
@@ -52,7 +58,7 @@ private:
 
     void map_dom_nodes_to_parent(JsonObject const* parent, JsonObject const* child);
 
-    GUI::TreeView& m_tree_view;
+    GUI::TreeView* m_tree_view { nullptr };
     GUI::Icon m_document_icon;
     GUI::Icon m_element_icon;
     GUI::Icon m_text_icon;