TextEditor: Add mixins for font settings

You can only set one text style but in many cases like
Function and Declaration it would be nice if they could be merged.

Change-Id: Icda892057b79eef1bea2fa8b2c5f0f7cbc5f518a
Reviewed-by: David Schulz <david.schulz@theqtcompany.com>

src/plugins/texteditor/fontsettings.cpp

@@ -139,8 +139,9 @@ bool FontSettings::equals(const FontSettings &f) const
  */
 QTextCharFormat FontSettings::toTextCharFormat(TextStyle category) const
 {
-    if (m_formatCache.contains(category))
+    auto textCharFormatIterator = m_formatCache.find(category);
-        return m_formatCache.value(category);
+    if (textCharFormatIterator != m_formatCache.end())
+        return *textCharFormatIterator;
 
     const Format &f = m_scheme.formatFor(category);
     QTextCharFormat tf;
@@ -174,6 +175,60 @@ QTextCharFormat FontSettings::toTextCharFormat(TextStyle category) const
     return tf;
 }
 
+uint qHash(const TextStyles &textStyles)
+{
+    uint hash = ::qHash(quint8(textStyles.mainStyle));
+
+    hash ^= ::qHashRange(textStyles.mixinStyles.cbegin(), textStyles.mixinStyles.cend());
+
+    return hash;
+}
+
+bool operator==(const TextStyles &first, const TextStyles &second)
+{
+    return first.mainStyle == second.mainStyle
+        && first.mixinStyles == second.mixinStyles;
+}
+
+void FontSettings::addMixinStyle(QTextCharFormat &textCharFormat,
+                                 const MixinTextStyles &mixinStyles) const
+{
+    for (TextStyle mixinStyle : mixinStyles) {
+        const QTextCharFormat mixinTextCharFormat = toTextCharFormat(mixinStyle);
+        if (!textCharFormat.hasProperty(QTextFormat::ForegroundBrush))
+            textCharFormat.setForeground(mixinTextCharFormat.foreground());
+
+        if (!textCharFormat.hasProperty(QTextFormat::BackgroundBrush))
+            textCharFormat.setBackground(mixinTextCharFormat.background());
+
+        if (!textCharFormat.fontItalic())
+            textCharFormat.setFontItalic(mixinTextCharFormat.fontItalic());
+
+        if (textCharFormat.fontWeight() == QFont::Normal)
+            textCharFormat.setFontWeight(mixinTextCharFormat.fontWeight());
+
+        if (textCharFormat.underlineStyle() == QTextCharFormat::NoUnderline) {
+            textCharFormat.setUnderlineStyle(mixinTextCharFormat.underlineStyle());
+            textCharFormat.setUnderlineColor(mixinTextCharFormat.underlineColor());
+        }
+    };
+}
+
+QTextCharFormat FontSettings::toTextCharFormat(const TextStyles textStyles) const
+{
+    auto textCharFormatIterator = m_textCharFormatCache.find(textStyles);
+    if (textCharFormatIterator != m_textCharFormatCache.end())
+        return *textCharFormatIterator;
+
+    QTextCharFormat textCharFormat = toTextCharFormat(textStyles.mainStyle);
+
+    addMixinStyle(textCharFormat, textStyles.mixinStyles);
+
+    m_textCharFormatCache.insert(textStyles, textCharFormat);
+
+    return textCharFormat;
+}
+
 /**
  * Returns the list of QTextCharFormats that corresponds to the list of
  * requested format categories.

src/plugins/texteditor/fontsettings.h

@@ -30,6 +30,8 @@
 
 #include "colorscheme.h"
 
+#include <utils/sizedarray.h>
+
 #include <QHash>
 #include <QList>
 #include <QString>
@@ -45,6 +47,13 @@ namespace TextEditor {
 
 class FormatDescription;
 
+using MixinTextStyles = Utils::SizedArray<TextStyle, 6>;
+
+struct TextStyles {
+    TextStyle mainStyle;
+    MixinTextStyles mixinStyles;
+};
+
 /**
  * Font settings (default font and enumerated list of formats).
  */
@@ -66,6 +75,7 @@ public:
 
     QVector<QTextCharFormat> toTextCharFormats(const QVector<TextStyle> &categories) const;
     QTextCharFormat toTextCharFormat(TextStyle category) const;
+    QTextCharFormat toTextCharFormat(const TextStyles textStyles) const;
 
     QString family() const;
     void setFamily(const QString &family);
@@ -99,6 +109,9 @@ public:
 
     static QString defaultSchemeFileName(const QString &fileName = QString());
 
+private:
+    void addMixinStyle(QTextCharFormat &textCharFormat, const MixinTextStyles &mixinStyles) const;
+
 private:
     QString m_family;
     QString m_schemeFileName;
@@ -107,6 +120,7 @@ private:
     bool m_antialias;
     ColorScheme m_scheme;
     mutable QHash<TextStyle, QTextCharFormat> m_formatCache;
+    mutable QHash<TextStyles, QTextCharFormat> m_textCharFormatCache;
 };
 
 inline bool operator==(const FontSettings &f1, const FontSettings &f2) { return f1.equals(f2); }

src/plugins/texteditor/texteditorconstants.h

@@ -31,7 +31,7 @@
 namespace TextEditor {
 
 // Text color and style categories
-enum TextStyle {
+enum TextStyle : quint8 {
     C_TEXT,
 
     C_LINK,