implement QFontDialog options similar to the QFontComboBox filters

so that QFontDialog can replace (functionality wise) KFontDialog and
KFontChooser

Signed-off-by: Ivailo Monev <xakepa10@gmail.com>

src/gui/dialogs/qfontdialog.cpp

@@ -207,9 +207,6 @@ void QFontDialogPrivate::init()
     sampleEdit->setText(QLatin1String("AaBbYyZz"));
     hbox->addWidget(sampleEdit);
 
-    size = 0;
-    smoothScalable = false;
-
     QObject::connect(familyList, SIGNAL(highlighted(int)), q, SLOT(_q_familyHighlighted(int)));
     QObject::connect(styleList, SIGNAL(highlighted(int)), q, SLOT(_q_styleHighlighted(int)));
     QObject::connect(sizeList, SIGNAL(highlighted(int)), q, SLOT(_q_sizeHighlighted(int)));
@@ -419,6 +416,22 @@ void QFontDialogPrivate::updateFamilies()
 
     QStringList familyNames = fdb.families();
 
+    const bool scalable = (opts & QFontDialog::ScalableFonts);
+    const bool mono = (opts & QFontDialog::MonospacedFonts);
+    if (!scalable || !mono) {
+        QMutableListIterator<QString> familyIter(familyNames);
+        while (familyIter.hasNext()) {
+            const QString family = familyIter.next();
+            if (scalable && !fdb.isScalable(family)) {
+                familyIter.remove();
+                continue;
+            }
+            if (mono && !fdb.isFixedPitch(family)) {
+                familyIter.remove();
+            }
+        }
+    }
+
     familyList->model()->setStringList(familyNames);
 
     QString foundryName1, familyName1, foundryName2, familyName2;
@@ -464,8 +477,9 @@ void QFontDialogPrivate::updateFamilies()
         familyList->setCurrentItem(0);
     familyEdit->setText(familyList->currentText());
     if (q->style()->styleHint(QStyle::SH_FontDialog_SelectAssociatedText, 0, q)
-            && familyList->hasFocus())
+        && familyList->hasFocus()) {
         familyEdit->selectAll();
+    }
 
     updateStyles();
 }
@@ -758,6 +772,9 @@ QFont QFontDialog::selectedFont() const
     of a font dialog.
 
     \value NoButtons Don't display \gui{OK} and \gui{Cancel} buttons. (Useful for "live dialogs".)
+    \value ScalableFonts Show scalable fonts
+    \value MonospacedFonts Show monospaced fonts
+    \value AllFonts Show scalable and monospaced fonts
 
     \sa options, setOption(), testOption()
 */
@@ -771,8 +788,9 @@ QFont QFontDialog::selectedFont() const
 void QFontDialog::setOption(FontDialogOption option, bool on)
 {
     Q_D(QFontDialog);
-    if (!(d->opts & option) != !on)
+    if (!(d->opts & option) != !on) {
         setOptions(d->opts ^ option);
+    }
 }
 
 /*!
@@ -784,7 +802,7 @@ void QFontDialog::setOption(FontDialogOption option, bool on)
 bool QFontDialog::testOption(FontDialogOption option) const
 {
     Q_D(const QFontDialog);
-    return (d->opts & option) != 0;
+    return (d->opts & option);
 }
 
 /*!
@@ -803,13 +821,12 @@ bool QFontDialog::testOption(FontDialogOption option) const
 void QFontDialog::setOptions(FontDialogOptions options)
 {
     Q_D(QFontDialog);
-
-    FontDialogOptions changed = (options ^ d->opts);
-    if (!changed)
+    if (d->opts == options) {
         return;
-
+    }
     d->opts = options;
     d->buttonBox->setVisible(!(options & NoButtons));
+    d->updateFamilies();
 }
 
 QFontDialog::FontDialogOptions QFontDialog::options() const
@@ -879,8 +896,9 @@ void QFontDialog::done(int result)
     if (result == Accepted) {
         // We check if this is the same font we had before, if so we emit currentFontChanged
         QFont selectedFont = currentFont();
-        if(selectedFont != d->selectedFont)
+        if (selectedFont != d->selectedFont) {
             emit(currentFontChanged(selectedFont));
+        }
         d->selectedFont = selectedFont;
         emit fontSelected(d->selectedFont);
     } else

src/gui/dialogs/qfontdialog.h

@@ -44,9 +44,11 @@ class Q_GUI_EXPORT QFontDialog : public QDialog
 
 public:
     enum FontDialogOption {
-        NoButtons = 0x00000001,
+        NoButtons = 0x01,
+        ScalableFonts = 0x2,
+        MonospacedFonts = 0x4,
+        AllFonts = (ScalableFonts | MonospacedFonts)
     };
-
     Q_DECLARE_FLAGS(FontDialogOptions, FontDialogOption)
 
     explicit QFontDialog(QWidget *parent = nullptr);
@@ -71,7 +73,7 @@ public:
     void open(QObject *receiver, const char *member);
 
     static QFont getFont(bool *ok, const QFont &initial, QWidget *parent = nullptr,
-                        const QString &title = QString(), FontDialogOptions options = 0);
+                        const QString &title = QString(), FontDialogOptions options = AllFonts);
     static QFont getFont(bool *ok, QWidget *parent = nullptr);
 
 
@@ -82,9 +84,6 @@ Q_SIGNALS:
 protected:
     void changeEvent(QEvent *event);
     void done(int result);
-
-private:
-    // ### Qt 5: make protected
     bool eventFilter(QObject *object, QEvent *event);
 
     Q_DISABLE_COPY(QFontDialog)
@@ -95,7 +94,6 @@ private:
     Q_PRIVATE_SLOT(d_func(), void _q_sizeHighlighted(int))
     Q_PRIVATE_SLOT(d_func(), void _q_updateSample())
 };
-
 Q_DECLARE_OPERATORS_FOR_FLAGS(QFontDialog::FontDialogOptions)
 
 #endif // QT_NO_FONTDIALOG

src/gui/dialogs/qfontdialog_p.h

@@ -56,7 +56,12 @@ class QFontDialogPrivate : public QDialogPrivate
     Q_DECLARE_PUBLIC(QFontDialog)
 
 public:
-    inline QFontDialogPrivate() { }
+    inline QFontDialogPrivate()
+        : size(0),
+        smoothScalable(false),
+        opts(QFontDialog::AllFonts)
+    {
+    }
 
     void updateFamilies();
     void updateStyles();