Use qreal for devicePixelRatio everywhere

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

Remove instances of casting to int.

Change-Id: I6e769d21e889bf8f88aedc1c49b53fef20a6709c

22 files changed, 68 insertions, 40 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());
     }
 }
diff --git a/src/opengl/qgl.cpp b/src/opengl/qgl.cpp
index 352b11b73d..ad99d3707f 100644
--- a/src/opengl/qgl.cpp
+++ b/src/opengl/qgl.cpp
@@ -4907,7 +4907,7 @@ void QGLWidget::renderText(double x, double y, double z, const QString &str, con
         GLdouble win_x = 0, win_y = 0, win_z = 0;
         qgluProject(x, y, z, &model[0], &proj[0], &view[0],
                     &win_x, &win_y, &win_z);
-        const int dpr = d->glcx->device()->devicePixelRatio();
+        const int dpr = d->glcx->device()->devicePixelRatioF();
         win_x /= dpr;
         win_y /= dpr;
         win_y = height - win_y; // y is inverted
diff --git a/src/opengl/qglframebufferobject.cpp b/src/opengl/qglframebufferobject.cpp
index 3479fccf58..8a03f9a0b7 100644
--- a/src/opengl/qglframebufferobject.cpp
+++ b/src/opengl/qglframebufferobject.cpp
@@ -1285,6 +1285,9 @@ int QGLFramebufferObject::metric(PaintDeviceMetric metric) const
     case QPaintDevice::PdmDevicePixelRatio:
         return 1;
 
+    case QPaintDevice::PdmDevicePixelRatioScaled:
+        return 1 * QPaintDevice::devicePixelRatioFScale;
+
     default:
         qWarning("QGLFramebufferObject::metric(), Unhandled metric type: %d.\n", metric);
         break;
diff --git a/src/opengl/qglpaintdevice.cpp b/src/opengl/qglpaintdevice.cpp
index 89cf01d8ec..16f1a3830e 100644
--- a/src/opengl/qglpaintdevice.cpp
+++ b/src/opengl/qglpaintdevice.cpp
@@ -62,6 +62,8 @@ int QGLPaintDevice::metric(QPaintDevice::PaintDeviceMetric metric) const
     }
     case PdmDevicePixelRatio:
         return 1;
+    case PdmDevicePixelRatioScaled:
+        return 1 * QPaintDevice::devicePixelRatioFScale;
     default:
         qWarning("QGLPaintDevice::metric() - metric %d not known", metric);
         return 0;
diff --git a/src/opengl/qglpixelbuffer.cpp b/src/opengl/qglpixelbuffer.cpp
index 49d2df9e1d..a9e3f15f9e 100644
--- a/src/opengl/qglpixelbuffer.cpp
+++ b/src/opengl/qglpixelbuffer.cpp
@@ -458,6 +458,9 @@ int QGLPixelBuffer::metric(PaintDeviceMetric metric) const
     case QPaintDevice::PdmDevicePixelRatio:
         return 1;
 
+    case QPaintDevice::PdmDevicePixelRatioScaled:
+        return QPaintDevice::devicePixelRatioFScale;
+
     default:
         qWarning("QGLPixelBuffer::metric(), Unhandled metric type: %d\n", metric);
         break;
diff --git a/src/plugins/platforms/cocoa/qcocoabackingstore.mm b/src/plugins/platforms/cocoa/qcocoabackingstore.mm
index 6a4f7ed8ee..cd8af5092a 100644
--- a/src/plugins/platforms/cocoa/qcocoabackingstore.mm
+++ b/src/plugins/platforms/cocoa/qcocoabackingstore.mm
@@ -54,6 +54,7 @@ QPaintDevice *QCocoaBackingStore::paintDevice()
     // Receate the backing store buffer if the effective buffer size has changed,
     // either due to a window resize or devicePixelRatio change.
     QSize effectiveBufferSize = m_requestedSize * windowDevicePixelRatio;
+
     if (m_qImage.size() != effectiveBufferSize) {
         QImage::Format format = (window()->format().hasAlpha() || cocoaWindow->m_drawContentBorderGradient)
                 ? QImage::Format_ARGB32_Premultiplied : QImage::Format_RGB32;
diff --git a/src/plugins/platforms/cocoa/qprintengine_mac.mm b/src/plugins/platforms/cocoa/qprintengine_mac.mm
index 348b537691..56fc720a83 100644
--- a/src/plugins/platforms/cocoa/qprintengine_mac.mm
+++ b/src/plugins/platforms/cocoa/qprintengine_mac.mm
@@ -212,6 +212,9 @@ int QMacPrintEngine::metric(QPaintDevice::PaintDeviceMetric m) const
     case QPaintDevice::PdmDevicePixelRatio:
         val = 1;
         break;
+    case QPaintDevice::PdmDevicePixelRatioScaled:
+        val = 1 * QPaintDevice::devicePixelRatioFScale;
+        break;
     default:
         val = 0;
         qWarning("QPrinter::metric: Invalid metric command");
diff --git a/src/plugins/platforms/direct2d/qwindowsdirect2dpaintdevice.cpp b/src/plugins/platforms/direct2d/qwindowsdirect2dpaintdevice.cpp
index fee9ad88fa..bc6590ef64 100644
--- a/src/plugins/platforms/direct2d/qwindowsdirect2dpaintdevice.cpp
+++ b/src/plugins/platforms/direct2d/qwindowsdirect2dpaintdevice.cpp
@@ -113,6 +113,9 @@ int QWindowsDirect2DPaintDevice::metric(QPaintDevice::PaintDeviceMetric metric)
     case QPaintDevice::PdmDevicePixelRatio:
         return 1;
         break;
+    case QPaintDevice::PdmDevicePixelRatioScaled:
+        return 1 * devicePixelRatioFScale;
+        break;
     case QPaintDevice::PdmWidthMM:
     case QPaintDevice::PdmHeightMM:
         return -1;
diff --git a/src/widgets/kernel/qopenglwidget.cpp b/src/widgets/kernel/qopenglwidget.cpp
index 9a0584bea9..7e4efc0e77 100644
--- a/src/widgets/kernel/qopenglwidget.cpp
+++ b/src/widgets/kernel/qopenglwidget.cpp
@@ -770,8 +770,8 @@ void QOpenGLWidgetPrivate::initialize()
     }
 
     paintDevice = new QOpenGLWidgetPaintDevice(q);
-    paintDevice->setSize(q->size() * q->devicePixelRatio());
-    paintDevice->setDevicePixelRatio(q->devicePixelRatio());
+    paintDevice->setSize(q->size() * q->devicePixelRatioF());
+    paintDevice->setDevicePixelRatio(q->devicePixelRatioF());
 
     context = ctx.take();
     initialized = true;
@@ -800,7 +800,7 @@ void QOpenGLWidgetPrivate::invokeUserPaint()
     QOpenGLFunctions *f = ctx->functions();
     QOpenGLContextPrivate::get(ctx)->defaultFboRedirect = fbo->handle();
 
-    f->glViewport(0, 0, q->width() * q->devicePixelRatio(), q->height() * q->devicePixelRatio());
+    f->glViewport(0, 0, q->width() * q->devicePixelRatioF(), q->height() * q->devicePixelRatioF());
     q->paintGL();
     flushPending = true;
 
@@ -851,8 +851,8 @@ QImage QOpenGLWidgetPrivate::grabFramebuffer()
     render();
     resolveSamples();
     q->makeCurrent();
-    QImage res = qt_gl_read_framebuffer(q->size() * q->devicePixelRatio(), false, false);
-    res.setDevicePixelRatio(q->devicePixelRatio());
+    QImage res = qt_gl_read_framebuffer(q->size() * q->devicePixelRatioF(), false, false);
+    res.setDevicePixelRatio(q->devicePixelRatioF());
 
     return res;
 }
@@ -871,7 +871,7 @@ void QOpenGLWidgetPrivate::resizeViewportFramebuffer()
     if (!initialized)
         return;
 
-    if (!fbo || q->size() * q->devicePixelRatio() != fbo->size())
+    if (!fbo || q->size() * q->devicePixelRatioF() != fbo->size())
         recreateFbo();
 }
 
@@ -1188,6 +1188,7 @@ int QOpenGLWidget::metric(QPaintDevice::PaintDeviceMetric metric) const
         return QWidget::metric(metric);
 
     QWidget *tlw = window();
+    QWindow *window = tlw ? tlw->windowHandle() : 0;
     QScreen *screen = tlw && tlw->windowHandle() ? tlw->windowHandle()->screen() : 0;
     if (!screen && QGuiApplication::primaryScreen())
         screen = QGuiApplication::primaryScreen();
@@ -1235,8 +1236,13 @@ int QOpenGLWidget::metric(QPaintDevice::PaintDeviceMetric metric) const
         else
             return qRound(dpmy * 0.0254);
     case PdmDevicePixelRatio:
-        if (screen)
-            return screen->devicePixelRatio();
+        if (window)
+            return int(window->devicePixelRatio());
+        else
+            return 1.0;
+    case PdmDevicePixelRatioScaled:
+        if (window)
+            return int(window->devicePixelRatio() * devicePixelRatioFScale);
         else
             return 1.0;
     default:
@@ -1296,7 +1302,7 @@ bool QOpenGLWidget::event(QEvent *e)
         }
         break;
     case QEvent::ScreenChangeInternal:
-        if (d->initialized && d->paintDevice->devicePixelRatio() != devicePixelRatio())
+        if (d->initialized && d->paintDevice->devicePixelRatioF() != devicePixelRatioF())
             d->recreateFbo();
         break;
     default:
diff --git a/src/widgets/kernel/qwidget.cpp b/src/widgets/kernel/qwidget.cpp
index 321cf0641c..4aec1b5d94 100644
--- a/src/widgets/kernel/qwidget.cpp
+++ b/src/widgets/kernel/qwidget.cpp
@@ -2029,7 +2029,7 @@ void QWidgetPrivate::setSystemClip(QPaintDevice *paintDevice, const QRegion &reg
 // Transform the system clip region from device-independent pixels to device pixels
     QPaintEngine *paintEngine = paintDevice->paintEngine();
     QTransform scaleTransform;
-    const qreal devicePixelRatio = paintDevice->devicePixelRatio();
+    const qreal devicePixelRatio = paintDevice->devicePixelRatioF();
     scaleTransform.scale(devicePixelRatio, devicePixelRatio);
     paintEngine->d_func()->systemClip = scaleTransform.map(region);
 }
@@ -5353,7 +5353,7 @@ void QWidgetPrivate::render_helper(QPainter *painter, const QPoint &targetOffset
         if (size.isNull())
             return;
 
-        const qreal pixmapDevicePixelRatio = qreal(painter->device()->devicePixelRatio());
+        const qreal pixmapDevicePixelRatio = painter->device()->devicePixelRatioF();
         QPixmap pixmap(size * pixmapDevicePixelRatio);
         pixmap.setDevicePixelRatio(pixmapDevicePixelRatio);
 
@@ -12647,8 +12647,7 @@ int QWidget::metric(PaintDeviceMetric m) const
     } else if (m == PdmDevicePixelRatio) {
         return topLevelWindow ? topLevelWindow->devicePixelRatio() : qApp->devicePixelRatio();
     } else if (m == PdmDevicePixelRatioScaled) {
-        return (topLevelWindow ? topLevelWindow->devicePixelRatio() : qApp->devicePixelRatio())
-            * QPaintDevice::devicePixelRatioFScale;
+        return (topLevelWindow ? topLevelWindow->devicePixelRatio() * QPaintDevice::devicePixelRatioFScale : qApp->devicePixelRatio());
     } else {
         val = QPaintDevice::metric(m);// XXX
     }
@@ -12864,7 +12863,7 @@ QDebug operator<<(QDebug debug, const QWidget *widget)
                                        frameGeometry.bottom() - geometry.bottom());
                 debug << ", margins=" << margins;
             }
-            debug << ", devicePixelRatio=" << widget->devicePixelRatio();
+            debug << ", devicePixelRatio=" << widget->devicePixelRatioF();
             if (const WId wid = widget->internalWinId())
                 debug << ", winId=0x" << hex << wid << dec;
         }
diff --git a/src/widgets/styles/qwindowsstyle_p_p.h b/src/widgets/styles/qwindowsstyle_p_p.h
index f1a4a390e1..a35ce3e6a1 100644
--- a/src/widgets/styles/qwindowsstyle_p_p.h
+++ b/src/widgets/styles/qwindowsstyle_p_p.h
@@ -66,7 +66,7 @@ public:
     static int pixelMetricFromSystemDp(QStyle::PixelMetric pm, const QStyleOption *option = 0, const QWidget *widget = 0);
     static int fixedPixelMetric(QStyle::PixelMetric pm);
     static int devicePixelRatio(const QWidget *widget = 0)
-        { return widget ? widget->devicePixelRatio() : QWindowsStylePrivate::appDevicePixelRatio(); }
+        { return widget ? int(widget->devicePixelRatioF()) : QWindowsStylePrivate::appDevicePixelRatio(); }
 
     bool hasSeenAlt(const QWidget *widget) const;
     bool altDown() const { return alt_down; }
diff --git a/src/widgets/widgets/qlabel.cpp b/src/widgets/widgets/qlabel.cpp
index 83e94c4128..fa1a5acb5f 100644
--- a/src/widgets/widgets/qlabel.cpp
+++ b/src/widgets/widgets/qlabel.cpp
@@ -1081,7 +1081,7 @@ void QLabel::paintEvent(QPaintEvent *)
                     d->cachedimage = new QImage(d->pixmap->toImage());
                 delete d->scaledpixmap;
                 QImage scaledImage =
-                    d->cachedimage->scaled(cr.size() * devicePixelRatio(),
+                    d->cachedimage->scaled(cr.size() * devicePixelRatioF(),
                                            Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
                 d->scaledpixmap = new QPixmap(QPixmap::fromImage(scaledImage));
             }