|
|
/*!
|
|
|
\example examples/populationpyramid
|
|
|
\title Population pyramid example
|
|
|
\subtitle
|
|
|
|
|
|
The example shows how to create a bar chart with bars extending in opposite directions. For example purposes we use population data found from wikipedia.
|
|
|
|
|
|
\image examples_populationpyramid.png
|
|
|
|
|
|
First we create two barsets and append the data to them. To make another barset grow to left, the values are negated.
|
|
|
|
|
|
\snippet ../examples/populationpyramid/main.cpp 1
|
|
|
|
|
|
We create the series and append the barsets to it. The series takes ownership of the barsets. We want the bars to be at same position on the y-axis, so we turn the
|
|
|
overlap drawing on. We also set the bar width to be 50% of the category width.
|
|
|
|
|
|
\snippet ../examples/populationpyramid/main.cpp 2
|
|
|
|
|
|
Here we create the chart object and add the series to it. We set the title for chart with setTitle and then turn on animations of the series by calling
|
|
|
setAnimationOptions(QChart::SeriesAnimations)
|
|
|
|
|
|
\snippet ../examples/populationpyramid/main.cpp 3
|
|
|
|
|
|
To have categories displayed on axis, we need to create a QBarCategoryAxis for that. Here we create a category axis with list of categories and
|
|
|
set it to be the y-axis of the chart. The chart takes ownership of axis. For x-axis we use default axis, which is created and scaled to series data
|
|
|
by calling createDefaultAxes of the chart. Note that the call for createDefaultAxes must be before we set the category axis. Otherwise the default axis will
|
|
|
override the category axis.
|
|
|
We also set the range for x-axis, since in this case it gives nicer result than autoscaling.
|
|
|
|
|
|
\snippet ../examples/populationpyramid/main.cpp 4
|
|
|
|
|
|
We also want to show the legend. To do that, we get the legend pointer from chart and set it to visible. We also place the legend to bottom of the chart by setting it's alignment
|
|
|
to Qt::AlignBottom.
|
|
|
|
|
|
\snippet ../examples/populationpyramid/main.cpp 5
|
|
|
|
|
|
Finally we add the chart onto a view. We also turn on the antialiasing for the chartView.
|
|
|
|
|
|
\snippet ../examples/populationpyramid/main.cpp 6
|
|
|
|
|
|
Chart is ready to be shown. We set the chart to be central widget of the window.
|
|
|
We also set the size for the chart window and show it.
|
|
|
|
|
|
\snippet ../examples/populationpyramid/main.cpp 7
|
|
|
*/
|
