I'm using Qt `charts` module to draw a [pie chart](http://doc.qt.io/QtCharts/qtcharts-piechart-example.html) directly on a PDF file. 

**Here's the problem**: 

* For some unknown reason, the chart needs to be displayed with `show()` before it's rendered to the PDF for it's size to be OK (left image).
* On the other hand, I don't want to have to display every chart on the screen since my application generates a lot of them. **However**, if the chart is not displayed in a window with `show()`, then the drawing gets too small in the PDF (right image) even though the size of the chart is properly set with `resize()`.

![](https://i.stack.imgur.com/4aVv5.png)
![](https://i.stack.imgur.com/C1LyL.png) 

*(black borders were added to these images to improve visualization)*

Displaying all charts on a window before they are rendered to the PDF is not an option. The fact that the chart needs to execute `show()` for QPainter to draw it to the PDF correctly seems to indicate that without it, QPainter ignores the chart's dimension.

On a side note, `show()` opens the window but it takes several seconds for the
chart to appear, so rendering is very very slow, another reason for me not to want to display the charts.

So here are my main questions:

* Are these bugs or am I missing something?
* If not, what would be the proper way to specify the size and *(x,y)* position of the drawing (in
the PDF)?

Here is a [Minimal, Complete, and Verifiable example](https://stackoverflow.com/help/mcve)...

**main.cpp**:

```
#include <QApplication>
#include <QtCharts/QChartView>
#include <QtCharts/QPieSeries>
#include <QtCharts/QPieSlice>
#include <QPainter>
#include <QPdfWriter>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    QtCharts::QChartView* chartView = new QtCharts::QChartView();
    chartView->setRenderHint(QPainter::Antialiasing);
    chartView->resize(640, 480);

    QtCharts::QChart* chart = chartView->chart();
    chart->setTitle("Beautiful Pie Chart");
    chart->legend()->hide();

    QtCharts::QPieSeries* series = new QtCharts::QPieSeries();
    float hits = 73.0f, misses = 27.0f;
    series->append("Hits", hits);
    series->append("Misses", misses);

    QtCharts::QPieSlice* hit_slice = series->slices().at(0);
    hit_slice->setBrush(QColor(87, 147, 243));  // blue

    QtCharts::QPieSlice* miss_slice = series->slices().at(1);
    miss_slice->setBrush(QColor(221, 68, 68)); // red

    chart->addSeries(series);

    // Due to Qt bug, must show() the chart before render()
    // or it will be draw too tiny in the PDF by QPainter
    chartView->show();

    QPdfWriter writer("out.pdf");
    writer.setCreator("https://stackoverflow.com/users/176769/karlphillip");
    writer.setPageSize(QPagedPaintDevice::A4);
    QPainter painter(&writer);

    chartView->render(&painter);

    painter.end();

    return a.exec();
}

```

**QtCharts\_PDF.pro**:

```
QT       += core gui charts

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = QtCharts_PDF
TEMPLATE = app
SOURCES += main.cpp

```