1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
|
/****************************************************************************
**
** Copyright (C) 2014 Digia Plc
** All rights reserved.
** For any questions to Digia, please use contact form at http://qt.io
**
** This file is part of the Qt Charts module.
**
** Licensees holding valid commercial license for Qt may use this file in
** accordance with the Qt License Agreement provided with the Software
** or, alternatively, in accordance with the terms contained in a written
** agreement between you and Digia.
**
** If you have questions regarding the use of this file, please use
** contact form at http://qt.io
**
****************************************************************************/
/*!
\example percentbarchart
\title PercentBarChart Example
\ingroup qtcharts_examples
\brief The example shows how to create a simple percent bar chart.
A percent bar chart shows the data in sets as a percentage of
all sets per category.
Creating percent bar charts is just like creating a regular \l {BarChart Example} {bar chart}, except that for a
percent bar charts, we use the QPercentBarSeries api instead of QBarSeries. Also, in the
\l {BarChart Example} {bar chart} we used the nice numbers algorithm to make the y-axis numbering look better. With
the percent bar chart there is no need for that, because the maximum y-axis value is always 100.
\image examples_percentbarchart.png
The barsets are used in same way in all barcharts.
To illustrate the difference between various barcharts, we use the same data in all examples.
The data visualized by the bar chart is defined by QBarSet instances. Here we create the sets and append data
to them. The data is appended here with the << operator. Alternatively the append method could be used.
\snippet percentbarchart/main.cpp 1
We create the series and append the barsets to it. The series takes ownership of the barsets. The series groups the data from sets to categories.
The first values of each set are grouped together in the first category, the second values in the second category etc.
\snippet percentbarchart/main.cpp 2
Here we create the chart object and add the series to it. We set the title of the chart with setTitle, and then turn on animations of the series by calling
setAnimationOptions(QChart::SeriesAnimations)
\snippet percentbarchart/main.cpp 3
To have categories displayed on axis, we need to create a QBarCategoryAxis for that. Here we create a category axis with a list of categories and
set it to be the x-axis of the chart. The chart takes ownership of the axis. For the y-axis we use the default axis, which is created and scaled
to series data by calling createDefaultAxes of the chart. Note that createDefaultAxes must be called before we set the category axis.
Otherwise the default axis will override the category axis.
\snippet percentbarchart/main.cpp 4
We also want to show the legend. To do so, we get the legend pointer from the chart and set it to visible. We also place the legend to bottom of
the chart by setting its alignment to Qt::AlignBottom.
\snippet percentbarchart/main.cpp 5
Finally we add the chart onto a view. We also turn on the antialiasing for the chartView.
\snippet percentbarchart/main.cpp 6
The 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 percentbarchart/main.cpp 7
*/
|
