# Tutorial (JKQTPlotter): Styling a JKQtPlotter {#JKQTPlotterStyling}
 
[TOC]
 
# Basic Description

This project (see `./examples/test_styling/`) demonstrates different types of user-interactions in JKQTPlotter.

It contains a simple plot with two graphs and provides several widgets that allow to modify the plot styling by editing an INI file:

![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/test_styling.png)


# Altering the Default Style

## Global/System-wide Settings

The `main()`-function can be found in  [`test_styling_main.cpp`](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/test_styling/test_styling_main.cpp). Here the Qt application  is initialized in the usual way and the main window `win` is created and shown. After instanciating the `QApplication`, but befor instanciating the window (and thus the JKQTPlotter), you can already alter the system-wide default styling. It is accessible via the function `JKQTPGetSystemDefaultStyle()`, which returns a reference to the central style object of type `JKQTPlotterStyle`. In the example below, the color of the user-actions (e.g. of the zooming rectangle, that can be drawn with the mouse) is set to red:

```.cpp
int main(int argc, char* argv[])
{
    QApplication app(argc, argv);

    // you can set the system-wide default style properties early on
    // all JKQTPlotter instance created after this, will use these
    // settings as their initial settings
    JKQTPGetSystemDefaultStyle().userActionFontSize=10;

    TestStyling win;
    win.show();

    return app.exec();
}
```

In addition to `JKQTPGetSystemDefaultStyle()`, which allows to style the `JKQTPlotter` (mainly the GUI-parts and user-action bindings), there is also `JKQTPGetSystemDefaultBaseStyle()`, which accesses a central instance of `JKQTBasePlotterStyle`. The latter object contains the styling of the graph itself (colors, axis properties, ...).

You can also store these settings in an INI-file (or any file supported by [`QSettings`](http://doc.qt.io/qt-5/qsettings.html)) and load such a file on startup, using:
```.cpp
	QSettings plotSettings("JKQTPlotterSettings.ini", QSettings::IniFormat);;
    JKQTPGetSystemDefaultStyle().loadSettings(plotSettings);
    JKQTPGetSystemDefaultBaseStyle().loadSettings(plotSettings);
```

## Apply a new Style to an Existing JKQTPlotter

The major part of the source code of the main application can be found in  [`test_styling.cpp`](https://github.com/jkriege2/JKQtPlotter/tree/master/examples/test_styling/test_styling.cpp). It opens a window with a plotter, that contains a set of test graphs to demonstrate the styling. The following function is connected to the "Update Graph"-button and applys the style defined by the INI in the plainTextEdit to the plotter:
```.cpp
    void TestStyling::on_btnUpdate_clicked()
    {
        QApplication::setOverrideCursor(QCursor(Qt::WaitCursor));
        // In this function, we store the data from the plainTextEdit into a temporary file
        // tmpfn and the use that file's contents to create a QSettings object, which is used
        // to read the plotterStyle into the JKQTPlotter-object ui->plot (using loadCurrentPlotterStyle(settings) )
        QString tmpfn=QDir::tempPath()+"/jkqtplotter_config.tmp";
        {
            QFile data(tmpfn);
            if (data.open(QFile::WriteOnly|QFile::Text)) {
              QTextStream out(&data);
              out << ui->plainTextEdit->toPlainText();
            }
        }
        {
            QSettings settings(tmpfn, QSettings::IniFormat);
            ui->plot->loadCurrentPlotterStyle(settings);
            initPlot();
            ui->chkDebugBoxes->setChecked(ui->plot->getPlotter()->isDebugShowRegionBoxesEnabled());
        }
        QFile::remove(tmpfn);
        QApplication::restoreOverrideCursor();
    }
```


# Some Example Styles
The following gallery shows a set of example styles:



| Style-file    | Screenshot    |
|:-------------:| ------------- | 
| <b> The Default Style </b> | ![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/style_default.png) |
| [`lib/jkqtplotter/resources/style/simple_gridandticks.ini`](https://github.com/jkriege2/JKQtPlotter/tree/master/lib/jkqtplotter/resources/styles/simple_gridandticks.ini) | ![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/style_simple_axesoffset_plotbox.png) |
| [`lib/jkqtplotter/resources/style/simple_axesoffset.ini`](https://github.com/jkriege2/JKQtPlotter/tree/master/lib/jkqtplotter/resources/styles/simple_axesoffset.ini) | ![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/style_simple_axesoffset.png) |
| [`lib/jkqtplotter/resources/style/simple_axesoffset_plotbox.ini`](https://github.com/jkriege2/JKQtPlotter/tree/master/lib/jkqtplotter/resources/styles/simple_axesoffset_plotbox.ini) | ![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/style_simple_axesoffset_plotbox.png) |
| [`lib/jkqtplotter/resources/style/dark.ini`](https://github.com/jkriege2/JKQtPlotter/tree/master/lib/jkqtplotter/resources/styles/dark.ini) | ![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/style_dark.png) |
| [`lib/jkqtplotter/resources/style/blueprint.ini`](https://github.com/jkriege2/JKQtPlotter/tree/master/lib/jkqtplotter/resources/styles/blueprint.ini) | ![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/style_blueprint.png) |
| [`lib/jkqtplotter/resources/style/blackandwhite.ini`](https://github.com/jkriege2/JKQtPlotter/tree/master/lib/jkqtplotter/resources/styles/blackandwhite.ini) | ![](https://raw.githubusercontent.com/jkriege2/JKQtPlotter/master/screenshots/style_blackandwhite.png) |


<b>Note:</b> The styles listed above are also linked into the executable as Qt ressource ... you can use them e.g. as follows:
```.cpp
	QSettings plotSettings(":/JKQTPlotter/styles/blackandwhite.ini", QSettings::IniFormat);;
    JKQTPGetSystemDefaultStyle().loadSettings(plotSettings);
    JKQTPGetSystemDefaultBaseStyle().loadSettings(plotSettings);
```