QColor: port to QStringView

... leveraging the existing support for QLatin1String, which is the
char equivalent of QStringView.

The only noteworthy changes here are the port of the low-level
functions to size_t and that the internal template function,
setColorFromString(), can now take its argument by value, since only
views are ever passed to it anymore.

In the test, used new QTest::addRow() to format test names, and
introduced temporaries to avoid re-calculating the same input values
for every check.

Change-Id: Ia3c59e5c435ff753f34993a8d85c0c0b4e8e2b22
Reviewed-by: Milian Wolff <milian.wolff@kdab.com>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

src/gui/painting/qcolor.cpp

@@ -79,7 +79,7 @@ static inline int hex2int(char s)
     return h < 0 ? h : (h << 4) | h;
 }
 
-static bool get_hex_rgb(const char *name, int len, QRgb *rgb)
+static bool get_hex_rgb(const char *name, size_t len, QRgb *rgb)
 {
     if (name[0] != '#')
         return false;
@@ -124,12 +124,12 @@ bool qt_get_hex_rgb(const char *name, QRgb *rgb)
     return get_hex_rgb(name, qstrlen(name), rgb);
 }
 
-static bool get_hex_rgb(const QChar *str, int len, QRgb *rgb)
+static bool get_hex_rgb(const QChar *str, size_t len, QRgb *rgb)
 {
     if (len > 13)
         return false;
     char tmp[16];
-    for (int i = 0; i < len; ++i)
+    for (size_t i = 0; i < len; ++i)
         tmp[i] = str[i].toLatin1();
     tmp[len] = 0;
     return get_hex_rgb(tmp, len, rgb);
@@ -858,6 +858,7 @@ QString QColor::name(NameFormat format) const
     return QString();
 }
 
+#if QT_STRINGVIEW_LEVEL < 2
 /*!
     Sets the RGB value of this QColor to \a name, which may be in one
     of these formats:
@@ -882,6 +883,17 @@ QString QColor::name(NameFormat format) const
 */
 
 void QColor::setNamedColor(const QString &name)
+{
+    setColorFromString(QStringView(name));
+}
+#endif
+
+/*!
+    \overload
+    \since 5.10
+*/
+
+void QColor::setNamedColor(QStringView name)
 {
     setColorFromString(name);
 }
@@ -896,6 +908,7 @@ void QColor::setNamedColor(QLatin1String name)
     setColorFromString(name);
 }
 
+#if QT_STRINGVIEW_LEVEL < 2
 /*!
    \since 4.7
 
@@ -909,7 +922,17 @@ void QColor::setNamedColor(QLatin1String name)
 */
 bool QColor::isValidColor(const QString &name)
 {
-    return !name.isEmpty() && QColor().setColorFromString(name);
+    return isValidColor(QStringView(name));
+}
+#endif
+
+/*!
+    \overload
+    \since 5.10
+*/
+bool QColor::isValidColor(QStringView name) Q_DECL_NOTHROW
+{
+    return name.size() && QColor().setColorFromString(name);
 }
 
 /*!
@@ -922,7 +945,7 @@ bool QColor::isValidColor(QLatin1String name) Q_DECL_NOTHROW
 }
 
 template <typename String>
-bool QColor::setColorFromString(const String &name)
+bool QColor::setColorFromString(String name)
 {
     if (!name.size()) {
         invalidate();

src/gui/painting/qcolor.h

@@ -72,7 +72,10 @@ public:
     inline QColor(int r, int g, int b, int a = 255);
     QColor(QRgb rgb) Q_DECL_NOTHROW;
     QColor(QRgba64 rgba64) Q_DECL_NOTHROW;
+#if QT_STRINGVIEW_LEVEL < 2
     inline QColor(const QString& name);
+#endif
+    explicit inline QColor(QStringView name);
     inline QColor(const char *aname) : QColor(QLatin1String(aname)) {}
     inline QColor(QLatin1String name);
     QColor(Spec spec) Q_DECL_NOTHROW;
@@ -95,7 +98,10 @@ public:
     QString name() const;
     QString name(NameFormat format) const;
 
+#if QT_STRINGVIEW_LEVEL < 2
     void setNamedColor(const QString& name);
+#endif
+    void setNamedColor(QStringView name);
     void setNamedColor(QLatin1String name);
 
     static QStringList colorNames();
@@ -221,14 +227,17 @@ public:
 
     operator QVariant() const;
 
+#if QT_STRINGVIEW_LEVEL < 2
     static bool isValidColor(const QString &name);
+#endif
+    static bool isValidColor(QStringView) Q_DECL_NOTHROW;
     static bool isValidColor(QLatin1String) Q_DECL_NOTHROW;
 
 private:
 
     void invalidate() Q_DECL_NOTHROW;
     template <typename String>
-    bool setColorFromString(const String &name);
+    bool setColorFromString(String name);
 
     Spec cspec;
     union {
@@ -280,8 +289,13 @@ inline QColor::QColor(int r, int g, int b, int a)
 inline QColor::QColor(QLatin1String aname)
 { setNamedColor(aname); }
 
+inline QColor::QColor(QStringView aname)
+{ setNamedColor(aname); }
+
+#if QT_STRINGVIEW_LEVEL < 2
 inline QColor::QColor(const QString& aname)
 { setNamedColor(aname); }
+#endif
 
 #if QT_VERSION < QT_VERSION_CHECK(6,0,0)
 inline QColor::QColor(const QColor &acolor) Q_DECL_NOTHROW

tests/auto/gui/painting/qcolor/tst_qcolor.cpp

@@ -545,19 +545,32 @@ void tst_QColor::setNamedColor_data()
             QColor bySetNamedColor;              \
             bySetNamedColor.setNamedColor(expr); \
             auto byCtor = QColor(expr);          \
-            QTest::newRow(e.name + QByteArrayLiteral(#expr)) \
+            QTest::addRow("%s: %s", e.name, #expr) \
                 << byCtor << bySetNamedColor << expected;    \
         } while (0)                              \
         /*end*/
 
-        ROW(QLatin1String(e.name));
-        ROW(QString(QLatin1String(e.name)));
+        const auto l1 = QLatin1String(e.name);
+        const auto l1UpperBA = QByteArray(e.name).toUpper();
+        const auto l1Upper = QLatin1String(l1UpperBA);
+        const auto l1SpaceBA = QByteArray(e.name).insert(1, ' ');
+        const auto l1Space = QLatin1String(l1SpaceBA);
+
+        const auto u16  = QString(l1);
+        const auto u16Upper = u16.toUpper();
+        const auto u16Space = QString(u16).insert(1, ' ');
+
+        ROW(l1);
+        ROW(u16);
+        ROW(QStringView(u16));
         // name should be case insensitive
-        ROW(QLatin1String(QByteArray(e.name).toUpper()));
-        ROW(QString(e.name).toUpper());
+        ROW(l1Upper);
+        ROW(u16Upper);
+        ROW(QStringView(u16Upper));
         // spaces should be ignored
-        ROW(QLatin1String(QByteArray(e.name).insert(1, ' ')));
-        ROW(QString(e.name).insert(1, ' '));
+        ROW(l1Space);
+        ROW(u16Space);
+        ROW(QStringView(u16Space));
 #undef ROW
     }
 }