README.md

matplotlib_backend_qtquick

This package implements a QtQuick backend for matplotlib. It started from maplotlib_qtquick_playground, written by Frédéric Collonval, but it has been updated to work with the current version (3.2.1) of matplotlib.

Usage

In order to use matplotlib plots with QtQuick, do the following:

1. In your main.py, use QtQml.qmlRegisterType to register FigureCanvasQtQuickAgg under whichever name you want to use.
2. In your QML files, instantiate an object with the QML type defined above. Its objectName property specifies the name of the object that can be found in the QML engine. It can be retrieved in python with win.findChild(QtCore.QObject, "spectFigure"), for example, where "spectFigure" is the objectName in this case.
3. One can then pass this object as needed. This is the FigureCanvasQtQuickAgg object. The figure can be found in its figure property.

For interactive plots, if you want to use the toolbar, to the Bridge class add slots like:

    @QtCore.Slot()
    def zoom(self, *args):
        """activate zoom tool."""
        self.toolbar.zoom(*args)

One can also connect to Matplotlib events:

       self._figure.canvas.mpl_connect('button_press_event', self.onClick)
       self._figure.canvas.mpl_connect('scroll_event', self.onScroll)

and provide the callbacks, for example:

    def onClick(self, event):
        """
        Handle mouse clicks in the three slices:
        set the slice to what is clicked.
        """
        if event.button == MouseButton.LEFT:
            if event.inaxes == self.axeses[0]:
                self.x = self._findBin(self.xAxis, event.xdata)
                self.y = self._findBin(self.yAxis, event.ydata)
                self.setSlice()
            elif event.inaxes == self.axeses[1]:
                self.x = self._findBin(self.xAxis, event.xdata)
                self.z = self._findBin(self.zAxis, event.ydata)
                self.setSlice()
            elif event.inaxes == self.axeses[2]:
                self.y = self._findBin(self.yAxis, event.xdata)
                self.z = self._findBin(self.zAxis, event.ydata)
                self.setSlice()

    def onScroll(self, event):
        """
        Handle mouse scroll in the three slices
        - scroll the independent variable
        """
        if event.inaxes == self.axeses[0]:
            self.z += int(event.step)
            self.setSlice()
        elif event.inaxes == self.axeses[1]:
            self.y += int(event.step)
            self.setSlice()
        elif event.inaxes == self.axeses[2]:
            self.x += int(event.step)
            self.setSlice()

Please let me know if you have any suggestions or better ways I should do this.

Examples

The example in the examples directory gives a simple example of how to use this backend, including interactions.