Move helper functions to more public location

Change-Id: I12a2000bfc82c194d12fb5c25302a06f782aa605
Reviewed-by: David Schulz <david.schulz@qt.io>

src/libs/utils/stylehelper.cpp

@@ -573,4 +573,39 @@ QList<int> StyleHelper::availableImageResolutions(const QString &fileName)
     return result;
 }
 
+static double luminance(const QColor &color)
+{
+    // calculate the luminance based on
+    // https://www.w3.org/TR/2008/REC-WCAG20-20081211/#relativeluminancedef
+    auto val = [](const double &colorVal) {
+        return colorVal < 0.03928 ? colorVal / 12.92 : std::pow((colorVal + 0.055) / 1.055, 2.4);
+    };
+
+    static QHash<QRgb, double> cache;
+    QHash<QRgb, double>::iterator it = cache.find(color.rgb());
+    if (it == cache.end()) {
+        it = cache.insert(color.rgb(), 0.2126 * val(color.redF())
+                          + 0.7152 * val(color.greenF())
+                          + 0.0722 * val(color.blueF()));
+    }
+    return it.value();
+}
+
+static double contrastRatio(const QColor &color1, const QColor &color2)
+{
+    // calculate the contrast ratio based on
+    // https://www.w3.org/TR/2008/REC-WCAG20-20081211/#contrast-ratiodef
+    auto contrast = (luminance(color1) + 0.05) / (luminance(color2) + 0.05);
+    if (contrast < 1)
+        return 1 / contrast;
+    return contrast;
+}
+
+bool StyleHelper::isReadableOn(const QColor &background, const QColor &foreground)
+{
+    // following the W3C Recommendation on contrast for large Text
+    // https://www.w3.org/TR/2008/REC-WCAG20-20081211/#contrast-ratiodef
+    return contrastRatio(background, foreground) > 3;
+}
+
 } // namespace Utils

src/libs/utils/stylehelper.h

@@ -97,6 +97,8 @@ public:
     static QString imageFileWithResolution(const QString &fileName, int dpr);
     static QList<int> availableImageResolutions(const QString &fileName);
 
+    static bool isReadableOn(const QColor &background, const QColor &foreground);
+
 private:
     static QColor m_baseColor;
     static QColor m_requestedBaseColor;

src/plugins/texteditor/highlighter.cpp

@@ -35,6 +35,7 @@
 #include <coreplugin/icore.h>
 #include <coreplugin/messagemanager.h>
 #include <utils/mimetypes/mimedatabase.h>
+#include <utils/stylehelper.h>
 #include <utils/qtcassert.h>
 
 #include <DefinitionDownloader>
@@ -46,8 +47,6 @@
 #include <QDir>
 #include <QMetaEnum>
 
-#include <cmath>
-
 using namespace TextEditor;
 
 static const char kDefinitionForMimeType[] = "definitionForMimeType";
@@ -338,41 +337,6 @@ void Highlighter::highlightBlock(const QString &text)
     formatSpaces(text);
 }
 
-static double luminance(const QColor &color)
-{
-    // calculate the luminance based on
-    // https://www.w3.org/TR/2008/REC-WCAG20-20081211/#relativeluminancedef
-    auto val = [](const double &colorVal) {
-        return colorVal < 0.03928 ? colorVal / 12.92 : std::pow((colorVal + 0.055) / 1.055, 2.4);
-    };
-
-    static QHash<QRgb, double> cache;
-    QHash<QRgb, double>::iterator it = cache.find(color.rgb());
-    if (it == cache.end()) {
-        it = cache.insert(color.rgb(), 0.2126 * val(color.redF())
-                                           + 0.7152 * val(color.greenF())
-                                           + 0.0722 * val(color.blueF()));
-    }
-    return it.value();
-}
-
-static double contrastRatio(const QColor &color1, const QColor &color2)
-{
-    // calculate the contrast ratio based on
-    // https://www.w3.org/TR/2008/REC-WCAG20-20081211/#contrast-ratiodef
-    auto contrast = (luminance(color1) + 0.05) / (luminance(color2) + 0.05);
-    if (contrast < 1)
-        return 1 / contrast;
-    return contrast;
-}
-
-static bool isReadableOn(const QColor &background, const QColor &foreground)
-{
-    // following the W3C Recommendation on contrast for large Text
-    // https://www.w3.org/TR/2008/REC-WCAG20-20081211/#contrast-ratiodef
-    return contrastRatio(background, foreground) > 3;
-}
-
 void Highlighter::applyFormat(int offset, int length, const KSyntaxHighlighting::Format &format)
 {
     const KSyntaxHighlighting::Theme defaultTheme;
@@ -382,18 +346,18 @@ void Highlighter::applyFormat(int offset, int length, const KSyntaxHighlighting:
         const QColor textColor = format.textColor(defaultTheme);
         if (format.hasBackgroundColor(defaultTheme)) {
             const QColor backgroundColor = format.hasBackgroundColor(defaultTheme);
-            if (isReadableOn(backgroundColor, textColor)) {
+            if (Utils::StyleHelper::isReadableOn(backgroundColor, textColor)) {
                 qformat.setForeground(textColor);
                 qformat.setBackground(backgroundColor);
-            } else if (isReadableOn(qformat.background().color(), textColor)) {
+            } else if (Utils::StyleHelper::isReadableOn(qformat.background().color(), textColor)) {
                 qformat.setForeground(textColor);
             }
-        } else if (isReadableOn(qformat.background().color(), textColor)) {
+        } else if (Utils::StyleHelper::isReadableOn(qformat.background().color(), textColor)) {
             qformat.setForeground(textColor);
         }
     } else if (format.hasBackgroundColor(defaultTheme)) {
         const QColor backgroundColor = format.hasBackgroundColor(defaultTheme);
-        if (isReadableOn(backgroundColor, qformat.foreground().color()))
+        if (Utils::StyleHelper::isReadableOn(backgroundColor, qformat.foreground().color()))
             qformat.setBackground(backgroundColor);
     }