Support for Plasma::Theme-themed stylesheets

This new API returns a stylesheet in Plasma theme colors and
can be used for hybrid widgets

svn path=/trunk/KDE/kdelibs/; revision=1125362

theme.cpp

@@ -135,6 +135,8 @@ public:
     void processWallpaperSettings(KConfigBase *metadata);
     void processAnimationSettings(const QString &theme, KConfigBase *metadata);
 
+    const QString processStyleSheet(const QString &css);
+
     static const char *defaultTheme;
     static const char *themeRcFile;
     static PackageStructure::Ptr packageStructure;
@@ -273,6 +275,54 @@ void ThemePrivate::colorsChanged()
     emit q->themeChanged();
 }
 
+const QString ThemePrivate::processStyleSheet(const QString &css)
+{
+    QString stylesheet;
+    if (css.isEmpty()) {
+        stylesheet = QString("\n\
+                    body {\n\
+                        color: %textcolor;\n\
+                        font-size: %fontsize;\n\
+                        font-family: %fontfamily;\n\
+                    }\n\
+                    a:active  { color: %activatedlink; }\n\
+                    a:link    { color: %link; }\n\
+                    a:visited { color: %visitedlink; }\n\
+                    a:hover   { color: %hoveredlink; text-decoration: none; }\n\
+                    ");
+    } else {
+        stylesheet = css;
+    }
+
+    QHash<QString, QString> elements;
+    // If you add elements here, make sure their names are sufficiently unique to not cause
+    // clashes between element keys
+    elements["%textcolor"] = Plasma::Theme::defaultTheme()->color(Plasma::Theme::TextColor).name();
+    elements["%backgroundcolor"] =
+                Plasma::Theme::defaultTheme()->color(Plasma::Theme::BackgroundColor).name();
+    elements["%visitedlink"] =
+                Plasma::Theme::defaultTheme()->color(Plasma::Theme::VisitedLinkColor).name();
+    elements["%activatedlink"] =
+                Plasma::Theme::defaultTheme()->color(Plasma::Theme::HighlightColor).name();
+    elements["%hoveredlink"] =
+                Plasma::Theme::defaultTheme()->color(Plasma::Theme::HighlightColor).name();
+    elements["%link"] = Plasma::Theme::defaultTheme()->color(Plasma::Theme::LinkColor).name();
+    elements["%buttonbackgroundcolor"] =
+                Plasma::Theme::defaultTheme()->color(Plasma::Theme::ButtonBackgroundColor).name();
+    elements["%smallfontsize"] =
+                QString("%1pt").arg(KGlobalSettings::smallestReadableFont().pointSize());
+
+    QFont font = Plasma::Theme::defaultTheme()->font(Plasma::Theme::DefaultFont);
+    elements["%fontsize"] =
+                QString("%1pt").arg(font.pointSize());
+    elements["%fontfamily"] = font.family();
+
+    foreach (const QString &k, elements.keys()) {
+        stylesheet.replace(k, elements[k]);
+    }
+    return stylesheet;
+}
+
 class ThemeSingleton
 {
 public:
@@ -580,6 +630,11 @@ QString Theme::imagePath(const QString &name) const
     return path;
 }
 
+QString Theme::styleSheet(const QString &css) const
+{
+    return d->processStyleSheet(css);
+}
+
 QString Theme::animationPath(const QString &name) const
 {
     const QString path = d->animationMapping.value(name);

theme.h

@@ -215,6 +215,46 @@ class PLASMA_EXPORT Theme : public QObject
          */
         bool useNativeWidgetStyle() const;
 
+        /**
+         * Provides a Plasma::Theme-themed stylesheet for hybrid (web / native Plasma) widgets.
+         *
+         * You can use this method to retrieve a basic default stylesheet, or to theme your
+         * custom stylesheet you use for example in Plasma::WebView. The QString you can pass
+         * into this method does not have to be a valid stylesheet, in fact you can use this
+         * method to replace color placeholders with the theme's color in any QString.
+         *
+         * In order to use this method with a custom stylesheet, just put for example %textcolor
+         * in your QString and it will be replaced with the theme's text (or foreground) color.
+         *
+         * Just like in many other methods for retrieving theme information, do not forget to
+         * update your stylesheet upon the themeChanged() signal.
+         *
+         * The following tags will be replaced by corresponding colors from Plasma::Theme:
+         *
+         * %textcolor
+         * %backgroundcolor
+         * %buttonbackgroundcolor
+         *
+         * %link
+         * %activatedlink
+         * %hoveredlink
+         * %visitedlink
+         *
+         * %fontfamily
+         * %fontsize
+         * %smallfontsize
+         *
+         * @param css a stylesheet to theme, leave empty for a default stylesheet containing
+         * theming for some commonly used elements, body text and links, for example.
+         *
+         * @return a piece of CSS that sets the most commonly used style elements to a theme
+         * matching Plasma::Theme.
+         *
+         * @since 4.5
+         */
+        Q_INVOKABLE QString styleSheet(const QString &css = QString()) const;
+
+
         /**
          * Tries to load pixmap with the specified key from cache.
          *