Edit Profile Dialog: Fix "Smooth fonts" preview

Summary:
`setStyleHint()` resets `styleStrategy` (which has information about
font smoothing) when the second argument is missing.

Test Plan:
* {nav Settings > Edit current profile... > Appearance}
* Unselect/select "Smooth fonts" checkbox

**Actual result:** text rendering in the main terminal window does not
change.
**Expected result:** text rendering in the main terminal window should
use smoothing or not, depending on the checkbox state. The option change
should be visible instantly, without clicking OK or Apply.

Reviewers: #konsole, hindenburg

Reviewed By: #konsole, hindenburg

Subscribers: hindenburg, konsole-devel

Tags: #konsole

Differential Revision: https://phabricator.kde.org/D16361

src/EditProfileDialog.cpp

@@ -624,6 +624,7 @@ void EditProfileDialog::setAntialiasText(bool enable)
 
     // update preview to reflect text smoothing state
     fontSelected(profileFont);
+    preview(Profile::AntiAliasFonts, enable);
     updateTempProfileProperty(Profile::AntiAliasFonts, enable);
 }
 

src/TerminalDisplay.cpp

@@ -240,10 +240,7 @@ void TerminalDisplay::fontChange(const QFont&)
 void TerminalDisplay::setVTFont(const QFont& f)
 {
     QFont newFont(f);
-
-    // In case the provided font doesn't have some specific characters it should
-    // fall back to a Monospace fonts.
-    newFont.setStyleHint(QFont::TypeWriter);
+    int strategy = 0;
 
     QFontMetrics fontMetrics(newFont);
 
@@ -257,38 +254,38 @@ void TerminalDisplay::setVTFont(const QFont& f)
         return;
     }
 
-    // hint that text should be drawn without anti-aliasing.
+    // hint that text should be drawn with- or without anti-aliasing.
     // depending on the user's font configuration, this may not be respected
-    if (!_antialiasText) {
-        newFont.setStyleStrategy(QFont::StyleStrategy(newFont.styleStrategy() | QFont::NoAntialias));
-    }
-
-    // experimental optimization.  Konsole assumes that the terminal is using a
-    // mono-spaced font, in which case kerning information should have an effect.
-    // Disabling kerning saves some computation when rendering text.
-    newFont.setKerning(false);
+    strategy |= _antialiasText ? QFont::PreferAntialias : QFont::NoAntialias;
 
     // Konsole cannot handle non-integer font metrics
-    newFont.setStyleStrategy(QFont::StyleStrategy(newFont.styleStrategy() | QFont::ForceIntegerMetrics));
+    strategy |= QFont::ForceIntegerMetrics;
+
+    // In case the provided font doesn't have some specific characters it should
+    // fall back to a Monospace fonts.
+    newFont.setStyleHint(QFont::TypeWriter, QFont::StyleStrategy(strategy));
 
     // Try to check that a good font has been loaded.
     // For some fonts, ForceIntegerMetrics causes height() == 0 which
     // will cause Konsole to crash later.
     QFontMetrics fontMetrics2(newFont);
-    if ((fontMetrics2.height() < 1)) {
+    if (fontMetrics2.height() < 1) {
         qCDebug(KonsoleDebug)<<"The font "<<newFont.toString()<<" has an invalid height()";
         // Ask for a generic font so at least it is usable.
         // Font listed in profile's dialog will not be updated.
         newFont = QFont(QStringLiteral("Monospace"));
-        newFont.setStyleHint(QFont::TypeWriter);
+        // Set style strategy without ForceIntegerMetrics for the font
+        strategy &= ~QFont::ForceIntegerMetrics;
+        newFont.setStyleHint(QFont::TypeWriter, QFont::StyleStrategy(strategy));
         qCDebug(KonsoleDebug)<<"Font changed to "<<newFont.toString();
     }
 
-    QFontInfo fontInfo(newFont);
+    // experimental optimization.  Konsole assumes that the terminal is using a
+    // mono-spaced font, in which case kerning information should have an effect.
+    // Disabling kerning saves some computation when rendering text.
+    newFont.setKerning(false);
 
-//    if (!fontInfo.fixedPitch()) {
-//        qWarning() << "Using a variable-width font - this might cause display problems";
-//    }
+    QFontInfo fontInfo(newFont);
 
     // QFontInfo::fixedPitch() appears to not match QFont::fixedPitch()
     // related?  https://bugreports.qt.io/browse/QTBUG-34082