Fix QCustmPlot retina problems.

Make sure our intermediate pixmaps have the same number of pixels as the
screen.

A merge request with the same changes has been made upstream.

Change-Id: I19950181d52f347e3aa7f5abb6e9ad33a4097abf
Reviewed-on: https://code.wireshark.org/review/7224
Reviewed-by: Gerald Combs <gerald@wireshark.org>

2 files changed, 24 insertions, 0 deletions

diff --git a/ui/qt/io_graph_dialog.cpp b/ui/qt/io_graph_dialog.cpp
index 9aa5abbe56..972eb2921a 100644
--- a/ui/qt/io_graph_dialog.cpp
+++ b/ui/qt/io_graph_dialog.cpp
@@ -183,6 +183,7 @@ static void io_graph_free_cb(void* p) {
 } // extern "C"
 
 
+#include <QDebug>
 Q_DECLARE_METATYPE(IOGraph *)
 
 IOGraphDialog::IOGraphDialog(QWidget &parent, CaptureFile &cf) :
@@ -209,6 +210,7 @@ IOGraphDialog::IOGraphDialog(QWidget &parent, CaptureFile &cf) :
     setWindowSubtitle(tr("IO Graphs"));
     setAttribute(Qt::WA_DeleteOnClose, true);
     QCustomPlot *iop = ui->ioPlot;
+    qDebug() << "=iop" << iop->rect() << iop->geometry() << iop->devicePixelRatio();
 
     QPushButton *save_bt = ui->buttonBox->button(QDialogButtonBox::Save);
     save_bt->setText(tr("Save As..."));
@@ -259,6 +261,7 @@ IOGraphDialog::IOGraphDialog(QWidget &parent, CaptureFile &cf) :
     iop->plotLayout()->insertRow(0);
     iop->plotLayout()->addElement(0, 0, title);
     title->setText(tr("Wireshark IO Graphs: %1").arg(cap_file_.fileTitle()));
+    title->setAntialiased(false);
 
     tracer_ = new QCPItemTracer(iop);
     iop->addItem(tracer_);
diff --git a/ui/qt/qcustomplot.cpp b/ui/qt/qcustomplot.cpp
index c92382e2de..398bdacee0 100644
--- a/ui/qt/qcustomplot.cpp
+++ b/ui/qt/qcustomplot.cpp
@@ -6398,7 +6398,14 @@ void QCPAxisPainterPrivate::placeTickLabel(QCPPainter *painter, double position,
       CachedLabel *newCachedLabel = new CachedLabel;
       TickLabelData labelData = getTickLabelData(painter->font(), text);
       newCachedLabel->offset = getTickLabelDrawOffset(labelData)+labelData.rotatedTotalBounds.topLeft();
+#if QT_VERSION >= QT_VERSION_CHECK(5, 0, 0)
+      QSize clSize = labelData.rotatedTotalBounds.size();
+      clSize *= painter->device()->devicePixelRatio();
+      newCachedLabel->pixmap = QPixmap(clSize);
+      newCachedLabel->pixmap.setDevicePixelRatio(painter->device()->devicePixelRatio());
+#else
       newCachedLabel->pixmap = QPixmap(labelData.rotatedTotalBounds.size());
+#endif
       newCachedLabel->pixmap.fill(Qt::transparent);
       QCPPainter cachePainter(&newCachedLabel->pixmap);
       cachePainter.setPen(painter->pen());
@@ -9064,6 +9071,13 @@ QCustomPlot::QCustomPlot(QWidget *parent) :
   currentLocale.setNumberOptions(QLocale::OmitGroupSeparator);
   setLocale(currentLocale);
 
+#if QT_VERSION >= QT_VERSION_CHECK(5, 0, 0)
+  QSize pbSize = mPaintBuffer.size();
+  pbSize *= devicePixelRatio();
+  mPaintBuffer = QPixmap(pbSize);
+  mPaintBuffer.setDevicePixelRatio(devicePixelRatio());
+#endif
+
   // create initial layers:
   mLayers.append(new QCPLayer(this, QLatin1String("background")));
   mLayers.append(new QCPLayer(this, QLatin1String("grid")));
@@ -10683,7 +10697,14 @@ void QCustomPlot::paintEvent(QPaintEvent *event)
 void QCustomPlot::resizeEvent(QResizeEvent *event)
 {
   // resize and repaint the buffer:
+#if QT_VERSION >= QT_VERSION_CHECK(5, 0, 0)
+  QSize pbSize = event->size();
+  pbSize *= devicePixelRatio();
+  mPaintBuffer = QPixmap(pbSize);
+  mPaintBuffer.setDevicePixelRatio(devicePixelRatio());
+#else
   mPaintBuffer = QPixmap(event->size());
+#endif
   setViewport(rect());
   replot(rpQueued); // queued update is important here, to prevent painting issues in some contexts
 }