1 files changed, 54 insertions, 23 deletions

diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp
index 3f387d575b..3af8fdea2e 100644
--- a/src/gui/painting/qpainter.cpp
+++ b/src/gui/painting/qpainter.cpp
@@ -229,16 +229,11 @@ QTransform QPainterPrivate::viewTransform() const
 
 int QPainterPrivate::effectiveDevicePixelRatio() const
 {
-    // Limited feature introduction for Qt 5.0.0, remove ifdef in a later release.
-#ifdef Q_OS_MAC
     // Special cases for devices that does not support PdmDevicePixelRatio go here:
     if (device->devType() == QInternal::Printer)
         return 1;
 
     return qMax(1, device->metric(QPaintDevice::PdmDevicePixelRatio));
-#else
-    return 1;
-#endif
 }
 
 QTransform QPainterPrivate::hidpiScaleTransform() const
@@ -1111,6 +1106,11 @@ void QPainterPrivate::updateState(QPainterState *newState)
     \li \inlineimage qpainter-pathstroking.png
     \endtable
 
+    Text drawing is done using drawText(). When you need
+    fine-grained positioning, boundingRect() tells you where a given
+    drawText() command will draw.
+
+    \section1 Drawing Pixmaps and Images
 
     There are functions to draw pixmaps/images, namely drawPixmap(),
     drawImage() and drawTiledPixmap(). Both drawPixmap() and drawImage()
@@ -1118,15 +1118,25 @@ void QPainterPrivate::updateState(QPainterState *newState)
     on-screen while drawImage() may be faster on a QPrinter or other
     devices.
 
-    Text drawing is done using drawText(). When you need
-    fine-grained positioning, boundingRect() tells you where a given
-    drawText() command will draw.
-
     There is a drawPicture() function that draws the contents of an
     entire QPicture. The drawPicture() function is the only function
     that disregards all the painter's settings as QPicture has its own
     settings.
 
+    \section2 Drawing High Resolution Versions of Pixmaps and Images
+
+    High resolution versions of pixmaps have a \e{device pixel ratio} value larger
+    than 1 (see QImageReader, QPixmap::devicePixelRatio()). Should it match the value
+    of the underlying QPaintDevice, it is drawn directly onto the device with no
+    additional transformation applied.
+
+    This is for example the case when drawing a QPixmap of 64x64 pixels size with
+    a device pixel ratio of 2 onto a high DPI screen which also has
+    a device pixel ratio of 2. Note that the pixmap is then effectively 32x32
+    pixels in \e{user space}. Code paths in Qt that calculate layout geometry
+    based on the pixmap size will use this size. The net effect of this is that
+    the pixmap is displayed as high DPI pixmap rather than a large pixmap.
+
     \section1 Rendering Quality
 
     To get the optimal rendering result using QPainter, you should use
@@ -5029,6 +5039,8 @@ static inline QPointF roundInDeviceCoordinates(const QPointF &p, const QTransfor
     into the given \a target in the paint device.
 
     \note The pixmap is scaled to fit the rectangle, if both the pixmap and rectangle size disagree.
+    \note See \l{Drawing High Resolution Versions of Pixmaps and Images} on how this is affected
+    by QPixmap::devicePixelRatio().
 
     \table 100%
     \row
@@ -5043,7 +5055,7 @@ static inline QPointF roundInDeviceCoordinates(const QPointF &p, const QTransfor
     transparent. Drawing bitmaps with gradient or texture colors is
     not supported.
 
-    \sa drawImage()
+    \sa drawImage(), QPixmap::devicePixelRatio()
 */
 void QPainter::drawPixmap(const QPointF &p, const QPixmap &pm)
 {
@@ -5607,6 +5619,8 @@ void QPainterPrivate::drawGlyphs(const quint32 *glyphArray, QFixedPoint *positio
         staticTextItem.numGlyphs = glyphCount;
         staticTextItem.glyphs = reinterpret_cast<glyph_t *>(const_cast<glyph_t *>(glyphArray));
         staticTextItem.glyphPositions = positions;
+        // The font property is meaningless, the fontengine must be used directly:
+        staticTextItem.usesRawFont = true;
 
         extended->drawStaticTextItem(&staticTextItem);
     } else {
@@ -6422,6 +6436,7 @@ void QPainterPrivate::drawTextItem(const QPointF &p, const QTextItem &_ti, QText
                 continue;
 
 
+            multi->ensureEngineAt(which);
             QTextItemInt ti2 = ti.midItem(multi->engine(which), start, end - start);
             ti2.width = 0;
             // set the high byte to zero and calc the width
@@ -6449,6 +6464,7 @@ void QPainterPrivate::drawTextItem(const QPointF &p, const QTextItem &_ti, QText
             which = e;
         }
 
+        multi->ensureEngineAt(which);
         QTextItemInt ti2 = ti.midItem(multi->engine(which), start, end - start);
         ti2.width = 0;
         // set the high byte to zero and calc the width
@@ -7404,8 +7420,6 @@ void qt_format_text(const QFont &fnt, const QRectF &_r,
         tf |= Qt::TextDontPrint;
 
     uint maxUnderlines = 0;
-    int numUnderlines = 0;
-    QVarLengthArray<int, 32> underlinePositions(1);
 
     QFontMetricsF fm(fnt);
     QString text = str;
@@ -7436,11 +7450,15 @@ start_lengthVariant:
         }
     }
 
+    // no need to do extra work for underlines if we don't paint
+    if (tf & Qt::TextDontPrint)
+        maxUnderlines = 0;
+
+    QList<QTextLayout::FormatRange> underlineFormats;
     int length = offset - old_offset;
     if ((hidemnmemonic || showmnemonic) && maxUnderlines > 0) {
-        underlinePositions.resize(maxUnderlines + 1);
-
         QChar *cout = text.data() + old_offset;
+        QChar *cout0 = cout;
         QChar *cin = cout;
         int l = length;
         while (l) {
@@ -7450,8 +7468,24 @@ start_lengthVariant:
                 --l;
                 if (!l)
                     break;
-                if (*cin != QLatin1Char('&') && !hidemnmemonic)
-                    underlinePositions[numUnderlines++] = cout - text.data() - old_offset;
+                if (*cin != QLatin1Char('&') && !hidemnmemonic) {
+                    QTextLayout::FormatRange range;
+                    range.start = cout - cout0;
+                    range.length = 1;
+                    range.format.setFontUnderline(true);
+                    underlineFormats.append(range);
+                }
+            } else if (hidemnmemonic && *cin == QLatin1Char('(') && l >= 4 &&
+                       cin[1] == QLatin1Char('&') && cin[2] != QLatin1Char('&') &&
+                       cin[3] == QLatin1Char(')')) {
+                int n = 0;
+                while ((cout - n) > cout0 && (cout - n - 1)->isSpace())
+                    ++n;
+                cout -= n;
+                cin += 4;
+                length -= n + 4;
+                l -= 4;
+                continue;
             }
             *cout = *cin;
             ++cout;
@@ -7460,11 +7494,6 @@ start_lengthVariant:
         }
     }
 
-    // no need to do extra work for underlines if we don't paint
-    if (tf & Qt::TextDontPrint)
-        numUnderlines = 0;
-
-    underlinePositions[numUnderlines] = -1;
     qreal height = 0;
     qreal width = 0;
 
@@ -7497,7 +7526,7 @@ start_lengthVariant:
         engine.forceJustification = true;
     QTextLayout textLayout(&engine);
     textLayout.setCacheEnabled(true);
-    textLayout.engine()->underlinePositions = underlinePositions.data();
+    textLayout.setAdditionalFormats(underlineFormats);
 
     if (finalText.isEmpty()) {
         height = fm.height();
@@ -7685,6 +7714,8 @@ void QPainterState::init(QPainter *p) {
     into the \a target rectangle in the paint device.
 
     \note The image is scaled to fit the rectangle, if both the image and rectangle size disagree.
+    \note See \l{Drawing High Resolution Versions of Pixmaps and Images} on how this is affected
+    by QImage::devicePixelRatio().
 
     If the image needs to be modified to fit in a lower-resolution
     result (e.g. converting from 32-bit to 8-bit), use the \a flags to
@@ -7696,7 +7727,7 @@ void QPainterState::init(QPainter *p) {
     \snippet code/src_gui_painting_qpainter.cpp 20
     \endtable
 
-    \sa drawPixmap()
+    \sa drawPixmap(), QImage::devicePixelRatio()
 */
 
 /*!