Use qreal for devicePixelRatio everywhere

QPaintDevice::devicePixelRatio() -> devicePixelRatioF()
Implement PdmDevicePixelRatioScaled for QPaintDevice subclasses.

Remove instances of casting to int.

Change-Id: I6e769d21e889bf8f88aedc1c49b53fef20a6709c

4 files changed, 10 insertions, 7 deletions

diff --git a/src/gui/painting/qbackingstore.cpp b/src/gui/painting/qbackingstore.cpp
index f81dcd3cd8..d35814df0a 100644
--- a/src/gui/painting/qbackingstore.cpp
+++ b/src/gui/painting/qbackingstore.cpp
@@ -131,7 +131,7 @@ QPaintDevice *QBackingStore::paintDevice()
             || source->size() != d_ptr->highDpiBackingstore->size()
             || source->devicePixelRatio() != d_ptr->highDpiBackingstore->devicePixelRatio();
         if (needsNewImage) {
-            qCDebug(lcScaling) << "QBackingStore::paintDevice new backingstore:";
+            qCDebug(lcScaling) << "QBackingStore::paintDevice new backingstore for" << d_ptr->window;
             qCDebug(lcScaling) << "  source size" << source->size() << "dpr" << source->devicePixelRatio();
             d_ptr->highDpiBackingstore.reset(
                 new QImage(source->bits(), source->width(), source->height(), source->format()));
diff --git a/src/gui/painting/qpaintdevice.h b/src/gui/painting/qpaintdevice.h
index 819116c585..c4ef9db766 100644
--- a/src/gui/painting/qpaintdevice.h
+++ b/src/gui/painting/qpaintdevice.h
@@ -81,8 +81,8 @@ public:
     int colorCount() const { return metric(PdmNumColors); }
     int depth() const { return metric(PdmDepth); }
 
-    // ### Classes that are not QPaintDevice subclasses are implementing metric()
-    // ### There needs to be some kind of (semi)-public API.
+    // ### Classes that are not QPaintDevice subclasses are implementing metric(),
+    // ### and need to access this constant. Add it here as a static constant for now
     static qreal devicePixelRatioFScale;
 protected:
     QPaintDevice();
diff --git a/src/gui/painting/qpainter.cpp b/src/gui/painting/qpainter.cpp
index 70862ea583..d3e8b542f0 100644
--- a/src/gui/painting/qpainter.cpp
+++ b/src/gui/painting/qpainter.cpp
@@ -223,14 +223,14 @@ qreal QPainterPrivate::effectiveDevicePixelRatio() const
 {
     // Special cases for devices that does not support PdmDevicePixelRatio go here:
     if (device->devType() == QInternal::Printer)
-        return 1;
+        return qreal(1);
 
-    return qMax(1, device->metric(QPaintDevice::PdmDevicePixelRatio));
+    return qMax(qreal(1), device->devicePixelRatioF());
 }
 
 QTransform QPainterPrivate::hidpiScaleTransform() const
 {
-    int devicePixelRatio = effectiveDevicePixelRatio();
+    const qreal devicePixelRatio = effectiveDevicePixelRatio();
     return QTransform::fromScale(devicePixelRatio, devicePixelRatio);
 }
 
@@ -5110,7 +5110,7 @@ void QPainter::drawPixmap(const QPointF &p, const QPixmap &pm)
             x += d->state->matrix.dx();
             y += d->state->matrix.dy();
         }
-        int scale = pm.devicePixelRatio();
+        qreal scale = pm.devicePixelRatio();
         d->engine->drawPixmap(QRectF(x, y, w / scale, h / scale), pm, QRectF(0, 0, w, h));
     }
 }
diff --git a/src/gui/painting/qpdf.cpp b/src/gui/painting/qpdf.cpp
index cc1ad02eee..ebb0e5f142 100644
--- a/src/gui/painting/qpdf.cpp
+++ b/src/gui/painting/qpdf.cpp
@@ -1502,6 +1502,9 @@ int QPdfEngine::metric(QPaintDevice::PaintDeviceMetric metricType) const
     case QPaintDevice::PdmDevicePixelRatio:
         val = 1;
         break;
+    case QPaintDevice::PdmDevicePixelRatioScaled:
+        val = 1 * QPaintDevice::devicePixelRatioFScale;
+        break;
     default:
         qWarning("QPdfWriter::metric: Invalid metric command");
         return 0;