Make QColor understand #AARRGGBB

This way I can have in my QtQuick something like
Text {
 text: "<font color='#ff0000'>H</font> <font color='#99ff0000'>H</font>"
}
and it works properly

QtQuick already supports #AARRGGBB for color: properties so I've
decided to go the notation

Once this is merged we can remove the extra code
in QQuickColorProvider::QColorFromString

I've also added some tests for the hex -> QColor conversion that where
non existent

Change-Id: I1dd4a2ec113293aec26968329b2e4930df6fdcb7
Reviewed-by: Gunnar Sletta <gunnar.sletta@digia.com>

3 files changed, 48 insertions, 8 deletions

diff --git a/src/gui/painting/qcolor.cpp b/src/gui/painting/qcolor.cpp
index 12ca84d8d1..aa3c3c4377 100644
--- a/src/gui/painting/qcolor.cpp
+++ b/src/gui/painting/qcolor.cpp
@@ -90,7 +90,8 @@ QT_BEGIN_NAMESPACE
     specified.
 
     A color can be set by passing an RGB string (such as "#112233"),
-    or a color name (such as "blue"), to the setNamedColor() function.
+    or an ARGB string (such as "#ff112233") or a color name (such as "blue"),
+    to the setNamedColor() function.
     The color names are taken from the SVG 1.0 color names. The name()
     function returns the name of the color in the format
     "#RRGGBB". Colors can also be set using setRgb(), setHsv() and
@@ -301,6 +302,17 @@ QT_BEGIN_NAMESPACE
 */
 
 /*!
+    \enum QColor::NameFormat
+
+    How to format the output of the name() function
+
+    \value HexRgb #RRGGBB A "#" character followed by three two-digit hexadecimal numbers (i.e. \c{#RRGGBB}).
+    \value HexArgb #AARRGGBB A "#" character followed by four two-digit hexadecimal numbers (i.e. \c{#AARRGGBB}).
+
+    \sa name()
+*/
+
+/*!
     \fn Spec QColor::spec() const
 
     Returns how the color was specified.
@@ -489,8 +501,26 @@ QColor::QColor(Spec spec)
 
 QString QColor::name() const
 {
+    return name(HexRgb);
+}
+
+/*!
+    Returns the name of the color in the specified \a format.
+
+    \sa setNamedColor(), NameFormat
+*/
+
+QString QColor::name(NameFormat format) const
+{
     QString s;
-    s.sprintf("#%02x%02x%02x", red(), green(), blue());
+    switch (format) {
+    case HexRgb:
+        s.sprintf("#%02x%02x%02x", red(), green(), blue());
+        break;
+    case HexArgb:
+        s.sprintf("#%02x%02x%02x%02x", alpha(), red(), green(), blue());
+        break;
+    }
     return s;
 }
 
@@ -501,6 +531,7 @@ QString QColor::name() const
     \list
     \li #RGB (each of R, G, and B is a single hex digit)
     \li #RRGGBB
+    \li #AARRGGBB
     \li #RRRGGGBBB
     \li #RRRRGGGGBBBB
     \li A name from the list of colors defined in the list of \l{http://www.w3.org/TR/SVG/types.html#ColorKeywords}{SVG color keyword names}
@@ -545,9 +576,9 @@ bool QColor::setColorFromString(const QString &name)
     }
 
     if (name.startsWith(QLatin1Char('#'))) {
-        QRgb rgb;
-        if (qt_get_hex_rgb(name.constData(), name.length(), &rgb)) {
-            setRgb(rgb);
+        QRgb rgba;
+        if (qt_get_hex_rgb(name.constData(), name.length(), &rgba)) {
+            setRgba(rgba);
             return true;
         } else {
             invalidate();
diff --git a/src/gui/painting/qcolor.h b/src/gui/painting/qcolor.h
index ef3503e8d8..1ede5a3682 100644
--- a/src/gui/painting/qcolor.h
+++ b/src/gui/painting/qcolor.h
@@ -65,6 +65,7 @@ class Q_GUI_EXPORT QColor
 {
 public:
     enum Spec { Invalid, Rgb, Hsv, Cmyk, Hsl };
+    enum NameFormat { HexRgb, HexArgb };
 
     QColor();
     QColor(Qt::GlobalColor color);
@@ -77,7 +78,9 @@ public:
 
     bool isValid() const;
 
+    // ### Qt 6: merge overloads
     QString name() const;
+    QString name(NameFormat format) const;
     void setNamedColor(const QString& name);
 
     static QStringList colorNames();
diff --git a/src/gui/painting/qcolor_p.cpp b/src/gui/painting/qcolor_p.cpp
index 35e607ec54..b913f5338c 100644
--- a/src/gui/painting/qcolor_p.cpp
+++ b/src/gui/painting/qcolor_p.cpp
@@ -79,7 +79,8 @@ bool qt_get_hex_rgb(const char *name, QRgb *rgb)
         return false;
     name++;
     int len = qstrlen(name);
-    int r, g, b;
+    int a, r, g, b;
+    a = 255;
     if (len == 12) {
         r = hex2int(name);
         g = hex2int(name + 4);
@@ -88,6 +89,11 @@ bool qt_get_hex_rgb(const char *name, QRgb *rgb)
         r = hex2int(name);
         g = hex2int(name + 3);
         b = hex2int(name + 6);
+    } else if (len == 8) {
+        a = hex2int(name);
+        r = hex2int(name + 2);
+        g = hex2int(name + 4);
+        b = hex2int(name + 6);
     } else if (len == 6) {
         r = hex2int(name);
         g = hex2int(name + 2);
@@ -99,11 +105,11 @@ bool qt_get_hex_rgb(const char *name, QRgb *rgb)
     } else {
         r = g = b = -1;
     }
-    if ((uint)r > 255 || (uint)g > 255 || (uint)b > 255) {
+    if ((uint)r > 255 || (uint)g > 255 || (uint)b > 255 || (uint)a > 255) {
         *rgb = 0;
         return false;
     }
-    *rgb = qRgb(r, g ,b);
+    *rgb = qRgba(r, g ,b, a);
     return true;
 }