LibWeb+WebContent: Forbid access to underlying type of CSSPixels

Although DistinctNumeric, which is supposed to abstract the underlying
type, was used to represent CSSPixels, we have a whole bunch of places
in the layout code that assume CSSPixels::value() returns a
floating-point type. This assumption makes it difficult to replace the
underlying type in CSSPixels with a non-floating type.

To make it easier to transition CSSPixels to fixed-point math, one step
we can take is to prevent access to the underlying type using value()
and instead use explicit conversions with the to_float(), to_double(),
and to_int() methods.

Userland/Libraries/LibWeb/CSS/EdgeRect.cpp

@@ -24,10 +24,10 @@ Gfx::FloatRect EdgeRect::resolved(Layout::Node const& layout_node, Gfx::Rect<dou
     // widths for <bottom>, and the same as the used value of the width plus the sum of the
     // horizontal padding and border widths for <right>, such that four 'auto' values result in the
     // clipping region being the same as the element's border box).
-    auto left = border_box.left() + (left_edge.is_auto() ? 0 : left_edge.to_px(layout_node)).value();
-    auto top = border_box.top() + (top_edge.is_auto() ? 0 : top_edge.to_px(layout_node)).value();
-    auto right = border_box.left() + (right_edge.is_auto() ? border_box.width() : right_edge.to_px(layout_node)).value();
-    auto bottom = border_box.top() + (bottom_edge.is_auto() ? border_box.height() : bottom_edge.to_px(layout_node)).value();
+    auto left = border_box.left() + (left_edge.is_auto() ? 0 : left_edge.to_px(layout_node)).to_double();
+    auto top = border_box.top() + (top_edge.is_auto() ? 0 : top_edge.to_px(layout_node)).to_double();
+    auto right = border_box.left() + (right_edge.is_auto() ? border_box.width() : right_edge.to_px(layout_node)).to_double();
+    auto bottom = border_box.top() + (bottom_edge.is_auto() ? border_box.height() : bottom_edge.to_px(layout_node)).to_double();
     return Gfx::FloatRect {
         left,
         top,

Userland/Libraries/LibWeb/CSS/Length.cpp

@@ -49,7 +49,7 @@ Length Length::make_auto()
 
 Length Length::make_px(CSSPixels value)
 {
-    return Length(value.value(), Type::Px);
+    return Length(value.to_double(), Type::Px);
 }
 
 Length Length::percentage_of(Percentage const& percentage) const
@@ -74,31 +74,31 @@ CSSPixels Length::font_relative_length_to_px(Length::FontMetrics const& font_met
 {
     switch (m_type) {
     case Type::Em:
-        return m_value * font_metrics.font_size;
+        return m_value * font_metrics.font_size.to_double();
     case Type::Rem:
-        return m_value * root_font_metrics.font_size;
+        return m_value * root_font_metrics.font_size.to_double();
     case Type::Ex:
-        return m_value * font_metrics.x_height;
+        return m_value * font_metrics.x_height.to_double();
     case Type::Rex:
-        return m_value * root_font_metrics.x_height;
+        return m_value * root_font_metrics.x_height.to_double();
     case Type::Cap:
-        return m_value * font_metrics.cap_height;
+        return m_value * font_metrics.cap_height.to_double();
     case Type::Rcap:
-        return m_value * root_font_metrics.cap_height;
+        return m_value * root_font_metrics.cap_height.to_double();
     case Type::Ch:
-        return m_value * font_metrics.zero_advance;
+        return m_value * font_metrics.zero_advance.to_double();
     case Type::Rch:
-        return m_value * root_font_metrics.zero_advance;
+        return m_value * root_font_metrics.zero_advance.to_double();
     case Type::Ic:
         // FIXME: Use the "advance measure of the “水” (CJK water ideograph, U+6C34) glyph"
-        return m_value * font_metrics.font_size;
+        return m_value * font_metrics.font_size.to_double();
     case Type::Ric:
         // FIXME: Use the "advance measure of the “水” (CJK water ideograph, U+6C34) glyph"
-        return m_value * root_font_metrics.font_size;
+        return m_value * root_font_metrics.font_size.to_double();
     case Type::Lh:
-        return m_value * font_metrics.line_height;
+        return m_value * font_metrics.line_height.to_double();
     case Type::Rlh:
-        return m_value * root_font_metrics.line_height;
+        return m_value * root_font_metrics.line_height.to_double();
     default:
         VERIFY_NOT_REACHED();
     }

Userland/Libraries/LibWeb/CSS/Screen.cpp

@@ -42,10 +42,10 @@ Gfx::IntRect Screen::screen_rect() const
 {
     auto screen_rect_in_css_pixels = window().page()->web_exposed_screen_area();
     return {
-        screen_rect_in_css_pixels.x().value(),
-        screen_rect_in_css_pixels.y().value(),
-        screen_rect_in_css_pixels.width().value(),
-        screen_rect_in_css_pixels.height().value()
+        screen_rect_in_css_pixels.x().to_int(),
+        screen_rect_in_css_pixels.y().to_int(),
+        screen_rect_in_css_pixels.width().to_int(),
+        screen_rect_in_css_pixels.height().to_int()
     };
 }
 

Userland/Libraries/LibWeb/CSS/StyleComputer.cpp

@@ -1888,7 +1888,7 @@ void StyleComputer::compute_font(StyleProperties& style, DOM::Element const* ele
         Optional<Length> maybe_length;
         if (font_size->is_percentage()) {
             // Percentages refer to parent element's font size
-            maybe_length = Length::make_px(static_cast<double>(font_size->as_percentage().percentage().as_fraction()) * parent_font_size());
+            maybe_length = Length::make_px(font_size->as_percentage().percentage().as_fraction() * parent_font_size().to_double());
 
         } else if (font_size->is_length()) {
             maybe_length = font_size->as_length().length();
@@ -1896,7 +1896,7 @@ void StyleComputer::compute_font(StyleProperties& style, DOM::Element const* ele
             maybe_length = font_size->as_calculated().resolve_length(length_resolution_context);
         }
         if (maybe_length.has_value()) {
-            auto px = maybe_length.value().to_px(length_resolution_context).value();
+            auto px = maybe_length.value().to_px(length_resolution_context).to_int();
             if (px != 0)
                 font_size_in_px = px;
         }

Userland/Libraries/LibWeb/CSS/StyleValues/CalculatedStyleValue.cpp

@@ -30,7 +30,7 @@ static double resolve_value(CalculatedStyleValue::CalculationResult::Value value
         [](Number const& number) { return number.value(); },
         [](Angle const& angle) { return angle.to_degrees(); },
         [](Frequency const& frequency) { return frequency.to_hertz(); },
-        [&context](Length const& length) { return length.to_px(*context).value(); },
+        [&context](Length const& length) { return length.to_px(*context).to_double(); },
         [](Percentage const& percentage) { return percentage.value(); },
         [](Time const& time) { return time.to_seconds(); });
 };

Userland/Libraries/LibWeb/CSS/StyleValues/FilterValueListStyleValue.cpp

@@ -18,7 +18,7 @@ float Filter::Blur::resolved_radius(Layout::Node const& node) const
     // Default value when omitted is 0px.
     auto sigma = 0;
     if (radius.has_value())
-        sigma = radius->to_px(node).value();
+        sigma = radius->to_px(node).to_int();
     // Note: The radius/sigma of the blur needs to be doubled for LibGfx's blur functions.
     return sigma * 2;
 }
@@ -28,9 +28,9 @@ Filter::DropShadow::Resolved Filter::DropShadow::resolved(Layout::Node const& no
     // The default value for omitted values is missing length values set to 0
     // and the missing used color is taken from the color property.
     return Resolved {
-        offset_x.to_px(node).value(),
-        offset_y.to_px(node).value(),
-        radius.has_value() ? radius->to_px(node).value() : 0.0,
+        offset_x.to_px(node).to_double(),
+        offset_y.to_px(node).to_double(),
+        radius.has_value() ? radius->to_px(node).to_double() : 0.0,
         color.has_value() ? *color : node.computed_values().color()
     };
 }

Userland/Libraries/LibWeb/CSS/StyleValues/LinearGradientStyleValue.cpp

@@ -66,7 +66,7 @@ bool LinearGradientStyleValue::equals(StyleValue const& other_) const
 float LinearGradientStyleValue::angle_degrees(CSSPixelSize gradient_size) const
 {
     auto corner_angle_degrees = [&] {
-        return atan2(gradient_size.height().value(), gradient_size.width().value()) * 180 / AK::Pi<double>;
+        return atan2(gradient_size.height().to_double(), gradient_size.width().to_double()) * 180 / AK::Pi<double>;
     };
     return m_properties.direction.visit(
         [&](SideOrCorner side_or_corner) {

Userland/Libraries/LibWeb/CSS/StyleValues/RadialGradientStyleValue.cpp

@@ -146,12 +146,12 @@ Gfx::FloatSize RadialGradientStyleValue::resolve_size(Layout::Node const& node,
         },
         [&](CircleSize const& circle_size) {
             auto radius = circle_size.radius.to_px(node);
-            return Gfx::FloatSize { radius.value(), radius.value() };
+            return Gfx::FloatSize { radius.to_float(), radius.to_float() };
         },
         [&](EllipseSize const& ellipse_size) {
             auto radius_a = ellipse_size.radius_a.resolved(node, CSS::Length::make_px(size.width())).to_px(node);
             auto radius_b = ellipse_size.radius_b.resolved(node, CSS::Length::make_px(size.height())).to_px(node);
-            return Gfx::FloatSize { radius_a.value(), radius_b.value() };
+            return Gfx::FloatSize { radius_a.to_float(), radius_b.to_float() };
         });
 
     // Handle degenerate cases