LibWeb: Implement "preserves overrides" property of editing commands

gmta · Dec 23, 2024 · b79ab2c · b79ab2c
1 parent 5ecde24
commit b79ab2c
Show file tree

Hide file tree

Showing 9 changed files with 322 additions and 82 deletions.
diff --git a/Libraries/LibWeb/CSS/StyleComputer.cpp b/Libraries/LibWeb/CSS/StyleComputer.cpp
@@ -1767,6 +1767,41 @@ RefPtr<Gfx::FontCascadeList const> StyleComputer::font_matching_algorithm(FlyStr
     return {};
 }
 
+CSSPixels StyleComputer::default_user_font_size() const
+{
+    // FIXME: This value should be configurable by the user.
+    return 16;
+}
+
+// https://w3c.github.io/csswg-drafts/css-fonts/#absolute-size-mapping
+CSSPixelFraction StyleComputer::absolute_size_mapping(Keyword keyword)
+{
+    switch (keyword) {
+    case Keyword::XxSmall:
+        return CSSPixels(3) / 5;
+    case Keyword::XSmall:
+        return CSSPixels(3) / 4;
+    case Keyword::Small:
+        return CSSPixels(8) / 9;
+    case Keyword::Medium:
+        return 1;
+    case Keyword::Large:
+        return CSSPixels(6) / 5;
+    case Keyword::XLarge:
+        return CSSPixels(3) / 2;
+    case Keyword::XxLarge:
+        return 2;
+    case Keyword::XxxLarge:
+        return 3;
+    case Keyword::Smaller:
+        return CSSPixels(4) / 5;
+    case Keyword::Larger:
+        return CSSPixels(5) / 4;
+    default:
+        return 1;
+    }
+}
+
 RefPtr<Gfx::FontCascadeList const> StyleComputer::compute_font_for_style_values(DOM::Element const* element, Optional<CSS::Selector::PseudoElement::Type> pseudo_element, CSSStyleValue const& font_family, CSSStyleValue const& font_size, CSSStyleValue const& font_style, CSSStyleValue const& font_weight, CSSStyleValue const& font_stretch, int math_depth) const
 {
     auto* parent_element = element_to_inherit_style_from(element, pseudo_element);
@@ -1776,8 +1811,7 @@ RefPtr<Gfx::FontCascadeList const> StyleComputer::compute_font_for_style_values(
     auto weight = font_weight.to_font_weight();
     bool bold = weight > Gfx::FontWeight::Regular;
 
-    // FIXME: Should be based on "user's default font size"
-    CSSPixels font_size_in_px = 16;
+    auto font_size_in_px = default_user_font_size();
 
     Gfx::FontPixelMetrics font_pixel_metrics;
     if (parent_element && parent_element->computed_properties())
@@ -1800,34 +1834,6 @@ RefPtr<Gfx::FontCascadeList const> StyleComputer::compute_font_for_style_values(
     Length::FontMetrics font_metrics { parent_font_size(), font_pixel_metrics };
 
     if (font_size.is_keyword()) {
-        // https://w3c.github.io/csswg-drafts/css-fonts/#absolute-size-mapping
-        auto get_absolute_size_mapping = [](Keyword keyword) -> CSSPixelFraction {
-            switch (keyword) {
-            case Keyword::XxSmall:
-                return CSSPixels(3) / 5;
-            case Keyword::XSmall:
-                return CSSPixels(3) / 4;
-            case Keyword::Small:
-                return CSSPixels(8) / 9;
-            case Keyword::Medium:
-                return 1;
-            case Keyword::Large:
-                return CSSPixels(6) / 5;
-            case Keyword::XLarge:
-                return CSSPixels(3) / 2;
-            case Keyword::XxLarge:
-                return 2;
-            case Keyword::XxxLarge:
-                return 3;
-            case Keyword::Smaller:
-                return CSSPixels(4) / 5;
-            case Keyword::Larger:
-                return CSSPixels(5) / 4;
-            default:
-                return 1;
-            }
-        };
-
         auto const keyword = font_size.to_keyword();
 
         if (keyword == Keyword::Math) {
@@ -1880,7 +1886,7 @@ RefPtr<Gfx::FontCascadeList const> StyleComputer::compute_font_for_style_values(
                     font_size_in_px = CSSPixels::nearest_value_for(parent_element->computed_properties()->first_available_computed_font().pixel_metrics().size);
                 }
             }
-            font_size_in_px *= get_absolute_size_mapping(keyword);
+            font_size_in_px *= absolute_size_mapping(keyword);
         }
     } else {
         Length::ResolutionContext const length_resolution_context {

diff --git a/Libraries/LibWeb/CSS/StyleComputer.h b/Libraries/LibWeb/CSS/StyleComputer.h
@@ -159,6 +159,8 @@ class StyleComputer {
     void load_fonts_from_sheet(CSSStyleSheet&);
     void unload_fonts_from_sheet(CSSStyleSheet&);
 
+    CSSPixels default_user_font_size() const;
+    static CSSPixelFraction absolute_size_mapping(Keyword);
     RefPtr<Gfx::FontCascadeList const> compute_font_for_style_values(DOM::Element const* element, Optional<CSS::Selector::PseudoElement::Type> pseudo_element, CSSStyleValue const& font_family, CSSStyleValue const& font_size, CSSStyleValue const& font_style, CSSStyleValue const& font_weight, CSSStyleValue const& font_stretch, int math_depth = 0) const;
 
     void set_viewport_rect(Badge<DOM::Document>, CSSPixelRect const& viewport_rect) { m_viewport_rect = viewport_rect; }

diff --git a/Libraries/LibWeb/Editing/Commands.cpp b/Libraries/LibWeb/Editing/Commands.cpp
@@ -798,6 +798,7 @@ static Array const commands {
     CommandDefinition {
         .command = CommandNames::delete_,
         .action = command_delete_action,
+        .preserves_overrides = true,
     },
     // https://w3c.github.io/editing/docs/execCommand/#the-defaultparagraphseparator-command
     CommandDefinition {
@@ -809,11 +810,13 @@ static Array const commands {
     CommandDefinition {
         .command = CommandNames::insertLineBreak,
         .action = command_insert_linebreak_action,
+        .preserves_overrides = true,
     },
     // https://w3c.github.io/editing/docs/execCommand/#the-insertparagraph-command
     CommandDefinition {
         .command = CommandNames::insertParagraph,
         .action = command_insert_paragraph_action,
+        .preserves_overrides = true,
     },
     // https://w3c.github.io/editing/docs/execCommand/#the-stylewithcss-command
     CommandDefinition {

diff --git a/Libraries/LibWeb/Editing/Commands.h b/Libraries/LibWeb/Editing/Commands.h
@@ -19,6 +19,9 @@ struct CommandDefinition {
     Function<String(DOM::Document const&)> value {};
     Optional<CSS::PropertyID> relevant_css_property {};
 
+    // https://w3c.github.io/editing/docs/execCommand/#preserves-overrides
+    bool preserves_overrides { false };
+
     // https://w3c.github.io/editing/docs/execCommand/#inline-command-activated-values
     Vector<String> inline_activated_values {};
 };

diff --git a/Libraries/LibWeb/Editing/ExecCommand.cpp b/Libraries/LibWeb/Editing/ExecCommand.cpp
@@ -69,12 +69,22 @@ bool Document::exec_command(FlyString const& command, [[maybe_unused]] bool show
         //    at the editing host that was actually affected.
     }
 
+    // https://w3c.github.io/editing/docs/execCommand/#preserves-overrides
+    // If a command preserves overrides, then before taking its action, the user agent must record current overrides.
+    auto overrides = Editing::record_current_overrides(*this);
+
     // 5. Take the action for command, passing value to the instructions as an argument.
     auto optional_command = Editing::find_command_definition(command);
     VERIFY(optional_command.has_value());
     auto const& command_definition = optional_command.release_value();
     auto command_result = command_definition.action(*this, value);
 
+    // https://w3c.github.io/editing/docs/execCommand/#preserves-overrides
+    // After taking the action, if the active range is collapsed, it must restore states and values from the recorded
+    // list.
+    if (m_selection && m_selection->is_collapsed())
+        Editing::restore_states_and_values(*this, overrides);
+
     // 6. If the previous step returned false, return false.
     if (!command_result)
         return false;