Use qreal for devicePixelRatio everywhere

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

Remove instances of casting to int.

Change-Id: I6e769d21e889bf8f88aedc1c49b53fef20a6709c

11 files changed, 31 insertions, 23 deletions

diff --git a/src/gui/image/qpicture.cpp b/src/gui/image/qpicture.cpp
index b63be19153..02a510ce29 100644
--- a/src/gui/image/qpicture.cpp
+++ b/src/gui/image/qpicture.cpp
@@ -961,6 +961,9 @@ int QPicture::metric(PaintDeviceMetric m) const
         case PdmDevicePixelRatio:
             val = 1;
             break;
+        case PdmDevicePixelRatioScaled:
+            val = 1 * QPaintDevice::devicePixelRatioFScale;
+            break;
         default:
             val = 0;
             qWarning("QPicture::metric: Invalid metric command");
diff --git a/src/gui/kernel/qopenglwindow.cpp b/src/gui/kernel/qopenglwindow.cpp
index a7ba57e85e..2853f05ef3 100644
--- a/src/gui/kernel/qopenglwindow.cpp
+++ b/src/gui/kernel/qopenglwindow.cpp
@@ -646,15 +646,10 @@ int QOpenGLWindow::metric(PaintDeviceMetric metric) const
             if (d->paintDevice)
                 return d->paintDevice->depth();
             break;
-        case PdmDevicePixelRatio:
-            if (d->paintDevice)
-                return devicePixelRatio();
-            break;
         default:
             break;
     }
     return QPaintDeviceWindow::metric(metric);
-
 }
 
 /*!
diff --git a/src/gui/kernel/qpaintdevicewindow.cpp b/src/gui/kernel/qpaintdevicewindow.cpp
index b32ab3b34d..32f0aeb6d5 100644
--- a/src/gui/kernel/qpaintdevicewindow.cpp
+++ b/src/gui/kernel/qpaintdevicewindow.cpp
@@ -144,8 +144,10 @@ int QPaintDeviceWindow::metric(PaintDeviceMetric metric) const
             return qRound(screen->physicalDotsPerInchY());
         break;
     case PdmDevicePixelRatio:
-        if (screen)
-            return screen->devicePixelRatio();
+        return int(QWindow::devicePixelRatio());
+        break;
+    case PdmDevicePixelRatioScaled:
+        return int(QWindow::devicePixelRatio() * devicePixelRatioFScale);
         break;
     default:
         break;
diff --git a/src/gui/kernel/qrasterwindow.cpp b/src/gui/kernel/qrasterwindow.cpp
index c04eb71420..fc1739ca0e 100644
--- a/src/gui/kernel/qrasterwindow.cpp
+++ b/src/gui/kernel/qrasterwindow.cpp
@@ -108,8 +108,6 @@ int QRasterWindow::metric(PaintDeviceMetric metric) const
     switch (metric) {
     case PdmDepth:
         return d->backingstore->paintDevice()->depth();
-    case PdmDevicePixelRatio:
-        return d->backingstore->paintDevice()->devicePixelRatio();
     default:
         break;
     }
diff --git a/src/gui/kernel/qwindow.cpp b/src/gui/kernel/qwindow.cpp
index 6b74bd66ed..e376df24cb 100644
--- a/src/gui/kernel/qwindow.cpp
+++ b/src/gui/kernel/qwindow.cpp
@@ -1082,13 +1082,17 @@ qreal QWindow::devicePixelRatio() const
 {
     Q_D(const QWindow);
 
-    // If there is no platform window, do the second best thing and
-    // return the app global devicePixelRatio. This is the highest
+    // Get the platform scale factor. If there is no platform window
+    // use the app global devicePixelRatio, which is the the highest
     // devicePixelRatio found on the system screens, and will be
     // correct for single-display systems (a very common case).
-    if (!d->platformWindow)
-        return qApp->devicePixelRatio();
-    return d->platformWindow->devicePixelRatio() * QHighDpiScaling::factor(this);
+    qreal ratio = d->platformWindow ? d->platformWindow->devicePixelRatio()
+                                    : qApp->devicePixelRatio();
+
+    //
+    ratio *= QHighDpiScaling::factor(this);
+
+    return ratio;
 }
 
 /*!
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;
diff --git a/src/gui/text/qstatictext.cpp b/src/gui/text/qstatictext.cpp
index fc95a859e7..38d83c485c 100644
--- a/src/gui/text/qstatictext.cpp
+++ b/src/gui/text/qstatictext.cpp
@@ -555,6 +555,9 @@ namespace {
             case PdmDevicePixelRatio:
                 val = 1;
                 break;
+            case PdmDevicePixelRatioScaled:
+                val = devicePixelRatioFScale;
+                break;
             default:
                 val = 0;
                 qWarning("DrawTextItemDevice::metric: Invalid metric command");
diff --git a/src/gui/text/qtextimagehandler.cpp b/src/gui/text/qtextimagehandler.cpp
index e85890baf2..1ba2cb31ca 100644
--- a/src/gui/text/qtextimagehandler.cpp
+++ b/src/gui/text/qtextimagehandler.cpp
@@ -256,10 +256,10 @@ void QTextImageHandler::drawObject(QPainter *p, const QRectF &rect, QTextDocumen
         const QTextImageFormat imageFormat = format.toImageFormat();
 
     if (QCoreApplication::instance()->thread() != QThread::currentThread()) {
-        const QImage image = getImage(doc, imageFormat, p->device()->devicePixelRatio());
+        const QImage image = getImage(doc, imageFormat, p->device()->devicePixelRatioF());
         p->drawImage(rect, image, image.rect());
     } else {
-        const QPixmap pixmap = getPixmap(doc, imageFormat, p->device()->devicePixelRatio());
+        const QPixmap pixmap = getPixmap(doc, imageFormat, p->device()->devicePixelRatioF());
         p->drawPixmap(rect, pixmap, pixmap.rect());
     }
 }