Support parsing animations in the CSS parser

Extend the CSS parser to include animations in the parsed rules. This
will help extending QtSvg module to support CSS animations.

Task-number: QTBUG-127592
Change-Id: I70d776c721f05f28126ae7406bd8fa499a5c2729
Reviewed-by: Eskil Abrahamsen Blomfeldt <[email protected]>
Reviewed-by: Eirik Aavitsland <[email protected]>

3 files changed, 129 insertions, 0 deletions

diff --git a/src/gui/text/qcssparser.cpp b/src/gui/text/qcssparser.cpp
index b894f539779..b58c17bcf79 100644
--- a/src/gui/text/qcssparser.cpp
+++ b/src/gui/text/qcssparser.cpp
@@ -2420,6 +2420,10 @@ bool Parser::parse(StyleSheet *styleSheet, Qt::CaseSensitivity nameCaseSensitivi
             PageRule rule;
             if (!parsePage(&rule)) return false;
             styleSheet->pageRules.append(rule);
+        } else if (testAnimation()) {
+            AnimationRule rule;
+            if (!parseAnimation(&rule)) return false;
+            styleSheet->animationRules.append(rule);
         } else if (testRuleset()) {
             StyleRule rule;
             if (!parseRuleset(&rule)) return false;
@@ -2546,6 +2550,72 @@ bool Parser::parseNextOperator(Value *value)
     return true;
 }
 
+bool Parser::parseAnimation(AnimationRule *animationRule)
+{
+    skipSpace();
+    if (!test(IDENT)) return false;
+
+    animationRule->animName = lexem();
+
+    if (!next(LBRACE)) return false;
+    skipSpace();
+
+    while (test(PERCENTAGE) || test(IDENT)) {
+        AnimationRule::AnimationRuleSet set;
+        if (lookup() == PERCENTAGE) {
+            QString name = lexem();
+            name.removeLast();
+            float keyFrame = name.toFloat() / 100;
+            set.keyFrame = keyFrame;
+        } else if (lookup() == IDENT) {
+            QString name;
+            if (parseElementName(&name)) {
+                if (name == QStringLiteral("from"))
+                    set.keyFrame = 0;
+                else if (name == QStringLiteral("to"))
+                    set.keyFrame = 1;
+            }
+        }
+
+        skipSpace();
+        if (!next(LBRACE)) return false;
+        const int declarationStart = index;
+
+        do {
+            skipSpace();
+            Declaration decl;
+            const int rewind = index;
+            if (!parseNextDeclaration(&decl)) {
+                index = rewind;
+                const bool foundSemicolon = until(SEMICOLON);
+                const int semicolonIndex = index;
+
+                index = declarationStart;
+                const bool foundRBrace = until(RBRACE);
+
+                if (foundSemicolon && semicolonIndex < index) {
+                    decl = Declaration();
+                    index = semicolonIndex - 1;
+                } else {
+                    skipSpace();
+                    return foundRBrace;
+                }
+            }
+            if (!decl.isEmpty())
+                set.declarations.append(decl);
+        } while (test(SEMICOLON));
+
+        if (!next(RBRACE)) return false;
+        skipSpace();
+        animationRule->ruleSets.append(set);
+    }
+
+    if (!next(RBRACE)) return false;
+    skipSpace();
+
+    return true;
+}
+
 bool Parser::parseCombinator(BasicSelector::Relation *relation)
 {
     *relation = BasicSelector::NoRelation;
diff --git a/src/gui/text/qcssparser_p.h b/src/gui/text/qcssparser_p.h
index ba4a611df34..22f71e0e8c2 100644
--- a/src/gui/text/qcssparser_p.h
+++ b/src/gui/text/qcssparser_p.h
@@ -600,6 +600,19 @@ struct PageRule
 };
 QT_CSS_DECLARE_TYPEINFO(PageRule, Q_RELOCATABLE_TYPE)
 
+struct AnimationRule
+{
+    struct AnimationRuleSet
+    {
+        float keyFrame;
+        QList<Declaration> declarations;
+    };
+
+    QString animName;
+    QList<AnimationRuleSet> ruleSets;
+};
+QT_CSS_DECLARE_TYPEINFO(AnimationRule, Q_RELOCATABLE_TYPE)
+
 struct ImportRule
 {
     QString href;
@@ -621,6 +634,7 @@ struct StyleSheet
     QList<StyleRule> styleRules; // only contains rules that are not indexed
     QList<MediaRule> mediaRules;
     QList<PageRule> pageRules;
+    QList<AnimationRule> animationRules;
     QList<ImportRule> importRules;
     StyleSheetOrigin origin;
     int depth; // applicable only for inline style sheets
@@ -752,6 +766,7 @@ public:
     bool parsePage(PageRule *pageRule);
     bool parsePseudoPage(QString *selector);
     bool parseNextOperator(Value *value);
+    bool parseAnimation(AnimationRule *animationRule);
     bool parseCombinator(BasicSelector::Relation *relation);
     bool parseProperty(Declaration *decl);
     bool parseRuleset(StyleRule *styleRule);
@@ -784,6 +799,7 @@ public:
     inline bool testImport() { return testTokenAndEndsWith(ATKEYWORD_SYM, QLatin1StringView("import")); }
     inline bool testMedia() { return testTokenAndEndsWith(ATKEYWORD_SYM, QLatin1StringView("media")); }
     inline bool testPage() { return testTokenAndEndsWith(ATKEYWORD_SYM, QLatin1StringView("page")); }
+    inline bool testAnimation() { return testTokenAndEndsWith(ATKEYWORD_SYM, QLatin1StringView("keyframes")); }
     inline bool testCombinator() { return test(PLUS) || test(GREATER) || test(TILDE) || test(S); }
     inline bool testProperty() { return test(IDENT); }
     bool testTerm();
diff --git a/tests/auto/gui/text/qcssparser/tst_qcssparser.cpp b/tests/auto/gui/text/qcssparser/tst_qcssparser.cpp
index 61731313317..ac1f54772bb 100644
--- a/tests/auto/gui/text/qcssparser/tst_qcssparser.cpp
+++ b/tests/auto/gui/text/qcssparser/tst_qcssparser.cpp
@@ -21,6 +21,7 @@ private slots:
     void expr();
     void import();
     void media();
+    void animation();
     void page();
     void ruleset();
     void selector_data();
@@ -398,6 +399,48 @@ void tst_QCssParser::media()
     QVERIFY(rule.styleRules.isEmpty());
 }
 
+void tst_QCssParser::animation()
+{
+    QCss::Parser parser("@keyframes emptyAnimation{} motion{from {x : 10;} to {x : 50;}} color{0% {fill : blue;} 25% {fill : yellow;} 100% {fill : red;}}");
+    QVERIFY(parser.testAnimation());
+
+    {
+        QCss::AnimationRule rule;
+        QVERIFY(parser.parseAnimation(&rule));
+        QCOMPARE(rule.animName, QStringLiteral("emptyAnimation"));
+        QCOMPARE(rule.ruleSets.size(), 0);
+    }
+
+    {
+        QCss::AnimationRule rule;
+        QVERIFY(parser.parseAnimation(&rule));
+        QCOMPARE(rule.animName, QStringLiteral("motion"));
+        QCOMPARE(rule.ruleSets.size(), 2);
+        QCOMPARE(rule.ruleSets[0].keyFrame, 0);
+        QCOMPARE(rule.ruleSets[1].keyFrame, 1);
+        QCOMPARE(rule.ruleSets[0].declarations[0].d->property, QStringLiteral("x"));
+        QCOMPARE(rule.ruleSets[0].declarations[0].d->values[0].toString(), QStringLiteral("10"));
+        QCOMPARE(rule.ruleSets[1].declarations[0].d->property, QStringLiteral("x"));
+        QCOMPARE(rule.ruleSets[1].declarations[0].d->values[0].toString(), QStringLiteral("50"));
+    }
+
+    {
+        QCss::AnimationRule rule;
+        QVERIFY(parser.parseAnimation(&rule));
+        QCOMPARE(rule.animName, QStringLiteral("color"));
+        QCOMPARE(rule.ruleSets.size(), 3);
+        QCOMPARE(rule.ruleSets[0].keyFrame, 0);
+        QCOMPARE(rule.ruleSets[1].keyFrame, 0.25);
+        QCOMPARE(rule.ruleSets[2].keyFrame, 1);
+        QCOMPARE(rule.ruleSets[0].declarations[0].d->property, QStringLiteral("fill"));
+        QCOMPARE(rule.ruleSets[0].declarations[0].d->values[0].toString(), QStringLiteral("blue"));
+        QCOMPARE(rule.ruleSets[1].declarations[0].d->property, QStringLiteral("fill"));
+        QCOMPARE(rule.ruleSets[1].declarations[0].d->values[0].toString(), QStringLiteral("yellow"));
+        QCOMPARE(rule.ruleSets[2].declarations[0].d->property, QStringLiteral("fill"));
+        QCOMPARE(rule.ruleSets[2].declarations[0].d->values[0].toString(), QStringLiteral("red"));
+    }
+}
+
 void tst_QCssParser::page()
 {
     QCss::Parser parser("@page :first/*comment to ignore*/{ }");