LibWeb: Move fragment link handling to Frame

Activating a "#foo" fragment link will now be handled internally by
the Frame instead of involving the widget layer.

If the viewport needs to be scrolled as a result, we will simply ask
the PageClient to scroll a new rect into view.

Applications/Browser/Tab.cpp

@@ -159,13 +159,8 @@ Tab::Tab()
             auto url = m_page_view->document()->complete_url(href);
             on_tab_open_request(url);
         } else {
-            if (href.starts_with("#")) {
-                auto anchor = href.substring_view(1, href.length() - 1);
-                m_page_view->scroll_to_anchor(anchor);
-            } else {
-                auto url = m_page_view->document()->complete_url(href);
-                m_page_view->load(url);
-            }
+            auto url = m_page_view->document()->complete_url(href);
+            m_page_view->load(url);
         }
     };
 

Libraries/LibWeb/Frame/EventHandler.cpp

@@ -131,6 +131,9 @@ bool EventHandler::handle_mousedown(const Gfx::IntPoint& position, unsigned butt
             auto href = link->href();
             if (href.starts_with("javascript:")) {
                 document.run_javascript(href.substring_view(11, href.length() - 11));
+            } else if (href.starts_with('#')) {
+                auto anchor = href.substring_view(1, href.length() - 1);
+                m_frame.scroll_to_anchor(anchor);
             } else {
                 if (m_frame.is_main_frame()) {
                     page_client.page_did_click_link(link->href(), link->target(), modifiers);

Libraries/LibWeb/Frame/Frame.cpp

@@ -25,6 +25,7 @@
  */
 
 #include <LibWeb/DOM/Document.h>
+#include <LibWeb/DOM/HTMLAnchorElement.h>
 #include <LibWeb/Frame/Frame.h>
 #include <LibWeb/Layout/LayoutDocument.h>
 #include <LibWeb/Layout/LayoutWidget.h>
@@ -116,9 +117,33 @@ void Frame::did_scroll(Badge<PageView>)
 
 void Frame::scroll_to_anchor(const String& fragment)
 {
-    // FIXME: This logic is backwards, the work should be done in here,
-    //        and then we just request that the "view" scrolls to a certain content offset.
-    page().client().page_did_request_scroll_to_anchor(fragment);
+    if (!document())
+        return;
+
+    const auto* element = document()->get_element_by_id(fragment);
+    if (!element) {
+        auto candidates = document()->get_elements_by_name(fragment);
+        for (auto* candidate : candidates) {
+            if (is<HTMLAnchorElement>(*candidate)) {
+                element = to<HTMLAnchorElement>(candidate);
+                break;
+            }
+        }
+    }
+
+    if (!element || !element->layout_node())
+        return;
+
+    auto& layout_node = *element->layout_node();
+
+    Gfx::FloatRect float_rect { layout_node.box_type_agnostic_position(), { (float)viewport_rect().width(), (float)viewport_rect().height() } };
+    if (is<LayoutBox>(layout_node)) {
+        auto& layout_box = to<LayoutBox>(layout_node);
+        auto padding_box = layout_box.box_model().padding_box(layout_box);
+        float_rect.move_by(-padding_box.left, -padding_box.top);
+    }
+
+    page().client().page_did_request_scroll_into_view(enclosing_int_rect(float_rect));
 }
 
 Gfx::IntRect Frame::to_main_frame_rect(const Gfx::IntRect& a_rect)

Libraries/LibWeb/Frame/Frame.h

@@ -71,6 +71,7 @@ public:
     EventHandler& event_handler() { return m_event_handler; }
     const EventHandler& event_handler() const { return m_event_handler; }
 
+    void scroll_to(const Gfx::IntPoint&);
     void scroll_to_anchor(const String&);
 
     Frame& main_frame() { return m_main_frame; }
@@ -82,6 +83,7 @@ public:
     Gfx::IntPoint to_main_frame_position(const Gfx::IntPoint&);
     Gfx::IntRect to_main_frame_rect(const Gfx::IntRect&);
 
+
 private:
     explicit Frame(Element& host_element, Frame& main_frame);
     explicit Frame(Page&);

Libraries/LibWeb/Page.h

@@ -82,10 +82,10 @@ public:
     virtual void page_did_leave_tooltip_area() { }
     virtual void page_did_hover_link(const URL&) { }
     virtual void page_did_unhover_link() { }
-    virtual void page_did_request_scroll_to_anchor([[maybe_unused]] const String& fragment) { }
     virtual void page_did_invalidate(const Gfx::IntRect&) { }
     virtual void page_did_change_favicon(const Gfx::Bitmap&) { }
     virtual void page_did_layout() { }
+    virtual void page_did_request_scroll_into_view(const Gfx::IntRect&) { }
 };
 
 }

Libraries/LibWeb/PageView.cpp

@@ -239,11 +239,6 @@ void PageView::page_did_unhover_link()
 {
 }
 
-void PageView::page_did_request_scroll_to_anchor(const String& fragment)
-{
-    scroll_to_anchor(fragment);
-}
-
 void PageView::page_did_invalidate(const Gfx::IntRect&)
 {
     update();
@@ -403,38 +398,9 @@ LayoutDocument* PageView::layout_root()
     return const_cast<LayoutDocument*>(document()->layout_node());
 }
 
-void PageView::scroll_to_anchor(const StringView& name)
+void PageView::page_did_request_scroll_into_view(const Gfx::IntRect& rect)
 {
-    if (!document())
-        return;
-
-    const auto* element = document()->get_element_by_id(name);
-    if (!element) {
-        auto candidates = document()->get_elements_by_name(name);
-        for (auto* candidate : candidates) {
-            if (is<HTMLAnchorElement>(*candidate)) {
-                element = to<HTMLAnchorElement>(candidate);
-                break;
-            }
-        }
-    }
-
-    if (!element) {
-        dbg() << "PageView::scroll_to_anchor(): Anchor not found: '" << name << "'";
-        return;
-    }
-    if (!element->layout_node()) {
-        dbg() << "PageView::scroll_to_anchor(): Anchor found but without layout node: '" << name << "'";
-        return;
-    }
-    auto& layout_node = *element->layout_node();
-    Gfx::FloatRect float_rect { layout_node.box_type_agnostic_position(), { (float)visible_content_rect().width(), (float)visible_content_rect().height() } };
-    if (is<LayoutBox>(layout_node)) {
-        auto& layout_box = to<LayoutBox>(layout_node);
-        auto padding_box = layout_box.box_model().padding_box(layout_box);
-        float_rect.move_by(-padding_box.left, -padding_box.top);
-    }
-    scroll_into_view(enclosing_int_rect(float_rect), true, true);
+    scroll_into_view(rect, true, true);
     window()->set_override_cursor(GUI::StandardCursor::None);
 }
 

Libraries/LibWeb/PageView.h

@@ -54,7 +54,6 @@ public:
 
     void reload();
     bool load(const URL&);
-    void scroll_to_anchor(const StringView&);
 
     URL url() const;
 
@@ -110,10 +109,10 @@ private:
     virtual void page_did_leave_tooltip_area() override;
     virtual void page_did_hover_link(const URL&) override;
     virtual void page_did_unhover_link() override;
-    virtual void page_did_request_scroll_to_anchor(const String& fragment) override;
     virtual void page_did_invalidate(const Gfx::IntRect&) override;
     virtual void page_did_change_favicon(const Gfx::Bitmap&) override;
     virtual void page_did_layout() override;
+    virtual void page_did_request_scroll_into_view(const Gfx::IntRect&) override;
 
     void layout_and_sync_size();