LibWeb: Move VideoPaintable's cached mouse position to HTMLVideoElement

The layout node, and therefore the painting box, is frequently destroyed
and recreated. This causes us to forget the cached mouse position we use
to highlight media controls. Move this cached position to the DOM node
instead, which survives relayout.

Userland/Libraries/LibWeb/HTML/HTMLVideoElement.h

@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include <AK/Optional.h>
 #include <LibGfx/Forward.h>
 #include <LibWeb/Forward.h>
 #include <LibWeb/HTML/HTMLMediaElement.h>
@@ -32,6 +33,9 @@ public:
     void set_current_frame(Badge<VideoTrack>, RefPtr<Gfx::Bitmap> frame);
     RefPtr<Gfx::Bitmap> const& current_frame() const { return m_current_frame; }
 
+    void set_layout_mouse_position(Badge<Painting::VideoPaintable>, Optional<CSSPixelPoint> mouse_position) { m_mouse_position = move(mouse_position); }
+    Optional<CSSPixelPoint> const& layout_mouse_position(Badge<Painting::VideoPaintable>) const { return m_mouse_position; }
+
 private:
     HTMLVideoElement(DOM::Document&, DOM::QualifiedName);
 
@@ -48,6 +52,9 @@ private:
 
     u32 m_video_width { 0 };
     u32 m_video_height { 0 };
+
+    // Cached state for layout
+    Optional<CSSPixelPoint> m_mouse_position;
 };
 
 }

Userland/Libraries/LibWeb/Painting/VideoPaintable.cpp

@@ -64,11 +64,13 @@ void VideoPaintable::paint(PaintContext& context, PaintPhase phase) const
     auto video_rect = context.rounded_device_rect(absolute_rect());
     ScopedCornerRadiusClip corner_clip { context, context.painter(), video_rect, normalized_border_radii_data(ShrinkRadiiForBorders::Yes) };
 
+    auto const& video_element = layout_box().dom_node();
+    auto const& layout_mouse_position = video_element.layout_mouse_position({});
+
     Optional<DevicePixelPoint> mouse_position;
-    if (m_mouse_position.has_value())
-        mouse_position = context.rounded_device_point(*m_mouse_position);
+    if (layout_mouse_position.has_value() && document().hovered_node() == &video_element)
+        mouse_position = context.rounded_device_point(*layout_mouse_position);
 
-    auto const& video_element = layout_box().dom_node();
     auto paint_user_agent_controls = video_element.has_attribute(HTML::AttributeNames::controls);
 
     if (auto const& bitmap = layout_box().dom_node().current_frame()) {
@@ -201,12 +203,14 @@ VideoPaintable::DispatchEventOfSameName VideoPaintable::handle_mouseup(Badge<Eve
 
 VideoPaintable::DispatchEventOfSameName VideoPaintable::handle_mousemove(Badge<EventHandler>, CSSPixelPoint position, unsigned, unsigned)
 {
+    auto& video_element = layout_box().dom_node();
+
     if (absolute_rect().contains(position)) {
-        m_mouse_position = position;
+        video_element.set_layout_mouse_position({}, position);
         return DispatchEventOfSameName::Yes;
     }
 
-    m_mouse_position.clear();
+    video_element.set_layout_mouse_position({}, {});
     return DispatchEventOfSameName::No;
 }
 

Userland/Libraries/LibWeb/Painting/VideoPaintable.h

@@ -6,7 +6,6 @@
 
 #pragma once
 
-#include <AK/Optional.h>
 #include <LibWeb/Forward.h>
 #include <LibWeb/Painting/PaintableBox.h>
 
@@ -32,8 +31,6 @@ private:
 
     void paint_loaded_video_controls(PaintContext&, HTML::HTMLVideoElement const&, DevicePixelRect video_rect, Optional<DevicePixelPoint> const& mouse_position) const;
     void paint_placeholder_video_controls(PaintContext&, DevicePixelRect video_rect, Optional<DevicePixelPoint> const& mouse_position) const;
-
-    Optional<CSSPixelPoint> m_mouse_position;
 };
 
 }