LibWeb: Transform ScrollFrame from a struct to a class

Author: https://github.com/kalenikaliaksandr
Commit: 112dd4af3b
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/1375

Userland/Libraries/LibWeb/DOM/Document.cpp

@@ -5570,10 +5570,10 @@ RefPtr<Painting::DisplayList> Document::record_display_list(PaintConfig config)
     Vector<RefPtr<Painting::ScrollFrame>> scroll_state;
     scroll_state.resize(viewport_paintable.scroll_state.size() + viewport_paintable.sticky_state.size());
     for (auto& [_, scrollable_frame] : viewport_paintable.scroll_state) {
-        scroll_state[scrollable_frame->id] = scrollable_frame;
+        scroll_state[scrollable_frame->id()] = scrollable_frame;
     }
     for (auto& [_, scrollable_frame] : viewport_paintable.sticky_state) {
-        scroll_state[scrollable_frame->id] = scrollable_frame;
+        scroll_state[scrollable_frame->id()] = scrollable_frame;
     }
 
     display_list->set_scroll_state(move(scroll_state));

Userland/Libraries/LibWeb/Painting/ClippableAndScrollable.cpp

@@ -12,14 +12,14 @@ namespace Web::Painting {
 Optional<int> ClippableAndScrollable::own_scroll_frame_id() const
 {
     if (m_own_scroll_frame)
-        return m_own_scroll_frame->id;
+        return m_own_scroll_frame->id();
     return {};
 }
 
 Optional<int> ClippableAndScrollable::scroll_frame_id() const
 {
     if (m_enclosing_scroll_frame)
-        return m_enclosing_scroll_frame->id;
+        return m_enclosing_scroll_frame->id();
     return {};
 }
 
@@ -51,7 +51,7 @@ void ClippableAndScrollable::apply_clip(PaintContext& context) const
     for (auto const& clip_rect : clip_rects) {
         Optional<i32> clip_scroll_frame_id;
         if (clip_rect.enclosing_scroll_frame)
-            clip_scroll_frame_id = clip_rect.enclosing_scroll_frame->id;
+            clip_scroll_frame_id = clip_rect.enclosing_scroll_frame->id();
         display_list_recorder.set_scroll_frame_id(clip_scroll_frame_id);
         auto rect = context.rounded_device_rect(clip_rect.rect).to_type<int>();
         auto corner_radii = clip_rect.corner_radii.as_corners(context);

Userland/Libraries/LibWeb/Painting/ClippableAndScrollable.h

@@ -28,7 +28,7 @@ public:
     [[nodiscard]] CSSPixelPoint own_scroll_frame_offset() const
     {
         if (m_own_scroll_frame)
-            return m_own_scroll_frame->own_offset;
+            return m_own_scroll_frame->own_offset();
         return {};
     }
     void set_own_scroll_frame(RefPtr<ScrollFrame> scroll_frame) { m_own_scroll_frame = scroll_frame; }

Userland/Libraries/LibWeb/Painting/DisplayList.cpp

@@ -37,7 +37,7 @@ void DisplayListPlayer::execute(DisplayList& display_list)
 
         if (command.has<PaintScrollBar>()) {
             auto& paint_scroll_bar = command.get<PaintScrollBar>();
-            auto const& scroll_offset = scroll_state[paint_scroll_bar.scroll_frame_id]->own_offset;
+            auto const& scroll_offset = scroll_state[paint_scroll_bar.scroll_frame_id]->own_offset();
             if (paint_scroll_bar.vertical) {
                 auto offset = scroll_offset.y() * paint_scroll_bar.scroll_size;
                 paint_scroll_bar.rect.translate_by(0, -offset.to_int() * device_pixels_per_css_pixel);

Userland/Libraries/LibWeb/Painting/ScrollFrame.h

@@ -10,17 +10,30 @@
 
 namespace Web::Painting {
 
-struct ScrollFrame : public RefCounted<ScrollFrame> {
+class ScrollFrame : public RefCounted<ScrollFrame> {
-    i32 id { -1 };
+public:
-    CSSPixelPoint own_offset;
+    ScrollFrame(i32 id, RefPtr<ScrollFrame const> parent)
-    RefPtr<ScrollFrame const> parent;
+        : m_id(id)
+        , m_parent(move(parent))
+    {
+    }
+
+    i32 id() const { return m_id; }
 
     CSSPixelPoint cumulative_offset() const
     {
-        if (parent)
+        if (m_parent)
-            return parent->cumulative_offset() + own_offset;
+            return m_parent->cumulative_offset() + m_own_offset;
-        return own_offset;
+        return m_own_offset;
     }
+
+    CSSPixelPoint own_offset() const { return m_own_offset; }
+    void set_own_offset(CSSPixelPoint offset) { m_own_offset = offset; }
+
+private:
+    i32 m_id { -1 };
+    RefPtr<ScrollFrame const> m_parent;
+    CSSPixelPoint m_own_offset;
 };
 
 }

Userland/Libraries/LibWeb/Painting/ViewportPaintable.cpp

@@ -70,25 +70,26 @@ void ViewportPaintable::assign_scroll_frames()
     for_each_in_inclusive_subtree_of_type<PaintableBox>([&](auto& paintable_box) {
         RefPtr<ScrollFrame> sticky_scroll_frame;
         if (paintable_box.is_sticky_position()) {
-            sticky_scroll_frame = adopt_ref(*new ScrollFrame());
-            sticky_scroll_frame->id = next_id++;
             auto const* nearest_scrollable_ancestor = paintable_box.nearest_scrollable_ancestor();
+            RefPtr<ScrollFrame const> parent_scroll_frame;
             if (nearest_scrollable_ancestor) {
-                sticky_scroll_frame->parent = nearest_scrollable_ancestor->nearest_scroll_frame();
+                parent_scroll_frame = nearest_scrollable_ancestor->nearest_scroll_frame();
             }
+            sticky_scroll_frame = adopt_ref(*new ScrollFrame(next_id++, parent_scroll_frame));
+
             const_cast<PaintableBox&>(paintable_box).set_enclosing_scroll_frame(sticky_scroll_frame);
             const_cast<PaintableBox&>(paintable_box).set_own_scroll_frame(sticky_scroll_frame);
             sticky_state.set(paintable_box, sticky_scroll_frame);
         }
 
         if (paintable_box.has_scrollable_overflow() || is<ViewportPaintable>(paintable_box)) {
-            auto scroll_frame = adopt_ref(*new ScrollFrame());
+            RefPtr<ScrollFrame const> parent_scroll_frame;
-            scroll_frame->id = next_id++;
             if (sticky_scroll_frame) {
-                scroll_frame->parent = sticky_scroll_frame;
+                parent_scroll_frame = sticky_scroll_frame;
             } else {
-                scroll_frame->parent = paintable_box.nearest_scroll_frame();
+                parent_scroll_frame = paintable_box.nearest_scroll_frame();
             }
+            auto scroll_frame = adopt_ref(*new ScrollFrame(next_id++, parent_scroll_frame));
             paintable_box.set_own_scroll_frame(scroll_frame);
             scroll_state.set(paintable_box, move(scroll_frame));
         }
@@ -252,13 +253,13 @@ void ViewportPaintable::refresh_scroll_state()
             }
         }
 
-        scroll_frame.own_offset = sticky_offset;
+        scroll_frame.set_own_offset(sticky_offset);
     }
 
     for (auto& it : scroll_state) {
         auto const& paintable_box = *it.key;
         auto& scroll_frame = *it.value;
-        scroll_frame.own_offset = -paintable_box.scroll_offset();
+        scroll_frame.set_own_offset(-paintable_box.scroll_offset());
     }
 }