Deprecate QFontDatabase::supportsThreadedFontRendering()

As of 5.0, this always return true.

Change-Id: If225c7219e283da97e870f0d66a87b21c3cacfc0
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

src/corelib/doc/src/threads.qdoc

@@ -655,11 +655,6 @@
     separate QImages, but the two threads cannot paint onto the same
     QImage at the same time.
 
-    Note that on X11 systems without FontConfig support, Qt cannot
-    render text outside of the GUI thread. You can use the
-    QFontDatabase::supportsThreadedFontRendering() function to detect
-    whether or not font rendering can be used outside the GUI thread.
-
     \section1 Threads and Rich Text Processing
 
     The QTextDocument, QTextCursor, and \l{richtext.html}{all related classes} are reentrant.

src/gui/painting/qpainter.cpp

@@ -6349,12 +6349,6 @@ void QPainterPrivate::drawTextItem(const QPointF &p, const QTextItem &_ti, QText
     if (!engine)
         return;
 
-#ifndef QT_NO_DEBUG
-    qt_painter_thread_test(device->devType(),
-                           "text and fonts",
-                           QFontDatabase::supportsThreadedFontRendering());
-#endif
-
     QTextItemInt &ti = const_cast<QTextItemInt &>(static_cast<const QTextItemInt &>(_ti));
 
     if (!extended && state->bgMode == Qt::OpaqueMode) {

src/gui/text/qfontdatabase.cpp

@@ -2167,12 +2167,15 @@ QFont QFontDatabase::systemFont(QFontDatabase::SystemFont type)
 /*!
     \fn bool QFontDatabase::supportsThreadedFontRendering()
     \since 4.4
+    \deprecated
 
     Returns true if font rendering is supported outside the GUI
     thread, false otherwise. In other words, a return value of false
     means that all QPainter::drawText() calls outside the GUI thread
     will not produce readable output.
 
+    As of 5.0, always returns true.
+
     \sa {Thread-Support in Qt Modules#Painting In Threads}{Painting In Threads}
 */
 

src/gui/text/qfontdatabase.h

@@ -150,7 +150,9 @@ public:
     static bool removeApplicationFont(int id);
     static bool removeAllApplicationFonts();
 
-    static bool supportsThreadedFontRendering();
+#if QT_DEPRECATED_SINCE(5, 2)
+    QT_DEPRECATED static inline bool supportsThreadedFontRendering() { return true; }
+#endif
 
     static QFont systemFont(SystemFont type);
 

src/gui/text/qfontdatabase_qpa.cpp

@@ -267,11 +267,6 @@ bool QFontDatabase::removeAllApplicationFonts()
     return true;
 }
 
-bool QFontDatabase::supportsThreadedFontRendering()
-{
-    return true;
-}
-
 /*!
     \internal
 */

tests/auto/gui/painting/qpainter/tst_qpainter.cpp

@@ -4444,9 +4444,6 @@ void TextDrawerThread::run()
 
 void tst_QPainter::drawTextOutsideGuiThread()
 {
-    if (!QFontDatabase::supportsThreadedFontRendering())
-        QSKIP("No threaded font rendering");
-
     QImage referenceRendering(100, 100, QImage::Format_ARGB32_Premultiplied);
     referenceRendering.fill(0);
     QPainter p(&referenceRendering);