HG_REPOSITORIES/LPP/INSTRUMENTATION/USERS/JEANDET/qtcharts Commit - r1888:7618c8da3444

Update donutbreakdown example docs

Jani Honkonen -

r1888:7618c8da3444

parent child

Context file:

r1888:7618c8da3444

Collapse all files

doc/src/examples-donutbreakdown.qdoc +15 -32

                   This example shows how to use create a donut breakdown chart using QPieSeries API.
-                  Let's start by creating a QChartView instance and enabling the Antialiasing on it. Last line enables the animations of the chart.
+                  Let's start by defining some data for the chart.
-                  \snippet ../examples/donutbreakdown/widget.cpp 1
+                  \snippet ../examples/donutbreakdown/main.cpp 1
-                  PieSeries is used to present the general data.
+                  Then we create a chart where we add the data. Note that this this is our own chart derived from QChart.
-                  \snippet ../examples/donutbreakdown/widget.cpp 2
+                  \snippet ../examples/donutbreakdown/main.cpp 2
-                  Following block of code creates the slices for the mainData QPieSeries.
-                  Then for every created slice a new series is created that stores the detailed data.
-                  The details series is set to be a donut. Its size is adjusted so that it wraps around the mainData pie.
-                  Next two signals from the mainData pie's slices are connected. This is used to keep the mainData slices agligned with their respective details series.
+                  Our own chart works so that in the constructor we create a main series
+                  which aggregates the data provided by the breakdown series. This is the piechart in the center.
-                  \snippet ../examples/donutbreakdown/widget.cpp 3
+                  \snippet ../examples/donutbreakdown/donutbreakdownchart.cpp 1
-                  Set the labels of the mainData to enabled and their postion to Outside.
-                  Then add the mainData and detailedData series to the chart.
+                  When a breakdown series is added the data is used to create a slice in the main series and the
+                  breakdown series itself is used to create a segment of a donut positioned so that it is aligned
+                  with the corresponding slice in the main series.
-                  \snippet ../examples/donutbreakdown/widget.cpp 4
+                  \snippet ../examples/donutbreakdown/donutbreakdownchart.cpp 2
-                  Finally the widget is placed in a layout used by the application.
+                  Here's how the start and end angles for the donut segments are calculated.
-                  \snippet ../examples/donutbreakdown/widget.cpp 5
+                  \snippet ../examples/donutbreakdown/donutbreakdownchart.cpp 3
-                  To show that the detailed data stays aligned with the main data every 2.5 sec. one of the slices is modified.
-                  It should be noted that int this example the mainData slices should not be modified directly as the change
-                  cannot be applied to the detailed slices without the extra knowledge on how the split looks like.
+                  And now that we have our chart defined we can finally create a QChartView and show the chart.
-                  \snippet ../examples/donutbreakdown/widget.cpp 6
-                  When the mainData slice layout is changed the detailed data layout has to be modified accordingly.
-                  This is achived by setting the start and end angle of the detailed series.
-                  \snippet ../examples/donutbreakdown/widget.cpp 7
-                  Highlight slot selects a random slice for the modification.
-                  The slice is set to exploded to notify the user that its going to be changed.
-                  The actual data modification is delayed by 1 sec to give a user a chance to focus on the slice.
-                  Then the slice is modified. Respective mainData slice is modified as well to contain as the value the sum of the detailed series slices values.
-                  Finally the slice exploded state is set to false.
-                  \snippet ../examples/donutbreakdown/widget.cpp 8
+                  \snippet ../examples/donutbreakdown/main.cpp 3
              */

doc/src/examples.qdoc +1 -2

                          <li><a href="examples-piechart.html">Pie chart</a></li>
                          <li><a href="examples-donutchart.html">Donut chart</a></li>
                          <li><a href="examples-piechartdrilldown.html">Pie chart drilldown</a></li>
-                         <li><a href="examples-donut.html">Nested donuts chart</a></li>
-                         <li><a href="examples-donutbreakdown.html">Donut chart drilldown</a></li>
+                         <li><a href="examples-donutbreakdown.html">Donut breakdown chart</a></li>
                          <li><a href="examples-presenterchart.html">Presenter chart</a></li>
                          <li><a href="examples-scatterchart.html">Scatter chart</a></li>
                          <li><a href="examples-scatterinteractions.html">Scatter interactions</a></li>

examples/donutbreakdown/donutbreakdownchart.cpp +8 -5

                  // create the series for main center pie
                  mainSeries = new QPieSeries();
                  mainSeries->setPieSize(0.7);
-                 addSeries(mainSeries);
+                 QChart::addSeries(mainSeries);
              }
              //![1]
                  }
                  // add the series to the chart
-                 addSeries(breakdownSeries);
+                 QChart::addSeries(breakdownSeries);
                  // recalculate breakdown donut segments
                  recalculateAngles();
              }
              //![2]
+             //![3]
              void DonutBreakdownChart::recalculateAngles()
              {
                  qreal angle = 0;
                      QPieSeries *s = find(slice->label());
                      if (s) {
                          s->setPieStartAngle(angle);
-                         angle += slice->percentage() * 360.0;
+                         angle += slice->percentage() * 360.0; // full pie is 360.0
                          s->setPieEndAngle(angle);
                      }
                  }
              }
+             //![3]
+             //![4]
              QPieSeries *DonutBreakdownChart::find(QString seriesName) const
              {
                  // find pieseries by name
-                 foreach (QAbstractSeries *series, this->series()) {
+                 foreach (QAbstractSeries *series, QChart::series()) {
                      QPieSeries *s = qobject_cast<QPieSeries*>(series);
                      if (!s)
                          continue;
                  }
                  return 0;
              }
+             //![4]

examples/donutbreakdown/main.cpp +1 -1

              {
                  QApplication a(argc, argv);
+                 //![1]
                  // Data from http://www.stat.fi/til/ekul/2010/ekul_2010_2011-12-13_tie_001_en.html
-                 //![1]
                  QPieSeries *series1 = new QPieSeries();
                  series1->setName("Fossil");
                  series1->append("Oil", 353295);

General Comments 0

Write
Preview

You need to be logged in to leave comments. Login now

No TODOs yet

	Site-wide shortcuts
/	Use quick search box
g h	Goto home page
g g	Goto my private gists page
g G	Goto my public gists page
g 0-9	Goto bookmarked items from 0-9
n r	New repository page
n g	New gist page

	Repositories
g s	Goto summary page
g c	Goto changelog page
g f	Goto files page
g F	Goto files page with file search activated
g p	Goto pull requests page
g o	Goto repository settings
g O	Goto repository access permissions settings
t s	Toggle sidebar on some pages