vaev-syle: Fix cascade order for useragent stylesheets.

src/vaev-driver/fetcher.cpp

@@ -115,11 +115,11 @@ Res<Strong<Markup::Document>> fetchDocument(Mime::Url const &url) {
     }
 }
 
-Res<Style::StyleSheet> fetchStylesheet(Mime::Url url) {
+Res<Style::StyleSheet> fetchStylesheet(Mime::Url url, Style::Origin origin) {
     auto file = try$(Sys::File::open(url));
     auto buf = try$(Io::readAllUtf8(file));
     Io::SScan s{buf};
-    return Ok(Style::StyleSheet::parse(s));
+    return Ok(Style::StyleSheet::parse(s, origin));
 }
 
 } // namespace Vaev::Driver

src/vaev-driver/fetcher.h

@@ -6,7 +6,7 @@
 
 namespace Vaev::Driver {
 
-Res<Style::StyleSheet> fetchStylesheet(Mime::Url url);
+Res<Style::StyleSheet> fetchStylesheet(Mime::Url url, Style::Origin origin = Style::Origin::AUTHOR);
 
 Res<Strong<Markup::Document>> fetchDocument(Mime::Url const &url);
 

src/vaev-driver/render.cpp

@@ -37,7 +37,7 @@ static void _collectStyle(Markup::Node const &node, Style::StyleBook &sb) {
                 return;
             }
 
-            auto sheet = fetchStylesheet(url.take());
+            auto sheet = fetchStylesheet(url.take(), Style::Origin::AUTHOR);
             if (not sheet) {
                 logWarn("failed to fetch stylesheet: {}", sheet);
                 return;
@@ -54,7 +54,7 @@ static void _collectStyle(Markup::Node const &node, Style::StyleBook &sb) {
 RenderResult render(Markup::Document const &dom, Style::Media const &media, Layout::Viewport viewport) {
     Style::StyleBook stylebook;
     stylebook.add(
-        fetchStylesheet("bundle://vaev-driver/user-agent.css"_url)
+        fetchStylesheet("bundle://vaev-driver/user-agent.css"_url, Style::Origin::USER_AGENT)
             .take("user agent stylesheet not available")
     );
 
@@ -113,7 +113,7 @@ RenderResult render(Markup::Document const &dom, Style::Media const &media, Layo
 Vec<Strong<Scene::Page>> print(Markup::Document const &dom, Style::Media const &media) {
     Style::StyleBook stylebook;
     stylebook.add(
-        fetchStylesheet("bundle://vaev-driver/user-agent.css"_url)
+        fetchStylesheet("bundle://vaev-driver/user-agent.css"_url, Style::Origin::USER_AGENT)
             .take("user agent stylesheet not available")
     );
 

src/vaev-style/computer.cpp

@@ -32,6 +32,7 @@ void Computer::_evalRule(Rule const &rule, Markup::Element const &el, MatchingRu
     });
 }
 
+// https://drafts.csswg.org/css-cascade/#cascade-origin
 Strong<Computed> Computer::computeFor(Computed const &parent, Markup::Element const &el) {
     MatchingRules matchingRules;
 
@@ -42,10 +43,12 @@ Strong<Computed> Computer::computeFor(Computed const &parent, Markup::Element co
         }
     }
 
-    // Sort rules by specificity
+    // Sort origin and specificity
     stableSort(
         matchingRules,
         [](auto const &a, auto const &b) {
+            if (a->origin != b->origin)
+                return a->origin <=> b->origin;
             return spec(a->selector) <=> spec(b->selector);
         }
     );
@@ -54,7 +57,6 @@ Strong<Computed> Computer::computeFor(Computed const &parent, Markup::Element co
     auto styleAttr = el.getAttribute(Html::STYLE_ATTR);
 
     StyleRule styleRule{
-        .selector = UNIVERSAL,
         .props = parseDeclarations<StyleProp>(styleAttr ? *styleAttr : ""),
     };
     matchingRules.pushBack(&styleRule);
@@ -73,7 +75,7 @@ Strong<Computed> Computer::computeFor(Computed const &parent, Markup::Element co
         }
     }
 
-    for (auto const &prop : importantProps)
+    for (auto const &prop : iterRev(importantProps))
         prop->apply(*computed);
 
     return computed;

src/vaev-style/origin.h

@@ -0,0 +1,23 @@
+#pragma once
+
+#include <karm-base/base.h>
+
+namespace Vaev::Style {
+
+// https://drafts.csswg.org/css-cascade/#origin
+enum struct Origin {
+    // NOTE: The order of these values is important
+    USER_AGENT,
+    USER,
+    AUTHOR,
+};
+
+static inline std::strong_ordering operator<=>(Origin a, Origin b) {
+    return static_cast<u8>(a) <=> static_cast<u8>(b);
+}
+
+static inline bool operator==(Origin a, Origin b) {
+    return static_cast<u8>(a) == static_cast<u8>(b);
+}
+
+} // namespace Vaev::Style

src/vaev-style/rules.cpp

@@ -24,7 +24,7 @@ void StyleRule::repr(Io::Emit &e) const {
     e(")");
 }
 
-StyleRule StyleRule::parse(Css::Sst const &sst) {
+StyleRule StyleRule::parse(Css::Sst const &sst, Origin origin) {
     if (sst != Css::Sst::RULE)
         panic("expected rule");
 
@@ -49,6 +49,7 @@ StyleRule StyleRule::parse(Css::Sst const &sst) {
         }
     }
 
+    res.origin = origin;
     return res;
 }
 
@@ -128,7 +129,7 @@ void Rule::repr(Io::Emit &e) const {
     });
 }
 
-Rule Rule::parse(Css::Sst const &sst) {
+Rule Rule::parse(Css::Sst const &sst, Origin origin) {
     if (sst != Css::Sst::RULE)
         panic("expected rule");
 
@@ -140,7 +141,7 @@ Rule Rule::parse(Css::Sst const &sst) {
     else if (tok.data == "@font-face")
         return FontFaceRule::parse(sst);
     else
-        return StyleRule::parse(sst);
+        return StyleRule::parse(sst, origin);
 }
 
 } // namespace Vaev::Style

src/vaev-style/rules.h

@@ -2,6 +2,7 @@
 
 #include "fonts.h"
 #include "media.h"
+#include "origin.h"
 #include "select.h"
 #include "styles.h"
 
@@ -11,16 +12,17 @@ struct Rule;
 
 // https://www.w3.org/TR/cssom-1/#the-cssstylerule-interface
 struct StyleRule {
-    Selector selector;
+    Selector selector = UNIVERSAL;
     Vec<StyleProp> props;
+    Origin origin = Origin::AUTHOR;
 
     void repr(Io::Emit &e) const;
 
     bool match(Markup::Element const &el) const {
         return selector.match(el);
     }
 
-    static StyleRule parse(Css::Sst const &sst);
+    static StyleRule parse(Css::Sst const &sst, Origin origin = Origin::AUTHOR);
 };
 
 // https://www.w3.org/TR/cssom-1/#the-cssimportrule-interface
@@ -65,7 +67,7 @@ struct Rule : public _Rule {
 
     void repr(Io::Emit &e) const;
 
-    static Rule parse(Css::Sst const &sst);
+    static Rule parse(Css::Sst const &sst, Origin origin = Origin::AUTHOR);
 };
 
 } // namespace Vaev::Style

src/vaev-style/stylesheet.cpp

@@ -22,19 +22,20 @@ void StyleSheet::repr(Io::Emit &e) const {
     e(")");
 }
 
-StyleSheet StyleSheet::parse(Css::Sst const &sst) {
+StyleSheet StyleSheet::parse(Css::Sst const &sst, Origin origin) {
     if (sst != Css::Sst::LIST)
         panic("expected list");
 
     Style::StyleSheet res;
     for (auto const &item : sst.content) {
         if (item == Css::Sst::RULE) {
-            res.rules.pushBack(Rule::parse(item));
+            res.rules.pushBack(Rule::parse(item, origin));
         } else {
             logWarn("unexpected item in stylesheet: {}", item.type);
         }
     }
 
+    res.origin = origin;
     return res;
 }
 

src/vaev-style/stylesheet.h

@@ -12,15 +12,20 @@ struct StyleSheet {
     Mime::Url href = ""_url;
     Str title = "";
     Vec<Rule> rules;
+    Origin origin = Origin::AUTHOR;
 
     void repr(Io::Emit &e) const;
 
-    static StyleSheet parse(Css::Sst const &sst);
+    static StyleSheet parse(Css::Sst const &sst, Origin origin = Origin::AUTHOR);
 
-    static Style::StyleSheet parse(Io::SScan &s) {
+    static Style::StyleSheet parse(Io::SScan &s, Origin origin = Origin::AUTHOR) {
         Css::Lexer lex{s};
         Css::Sst sst = consumeRuleList(lex, true);
-        return parse(sst);
+        return parse(sst, origin);
+    }
+
+    void add(Rule &&rule) {
+        rules.pushBack(std::move(rule));
     }
 };
 

src/vaev-view/view.cpp

@@ -68,8 +68,6 @@ struct View : public Ui::View<View> {
 
         paint->paint(g, rect.offset(-bound().xy).cast<f64>());
         if (Ui::debugShowLayoutBounds) {
-            logDebug("layout tree: {}", layout);
-            logDebug("paint tree: {}", paint);
             Layout::wireframe(*layout, g);
         }