qt - Qt5 / PyQt5 : Custom QML components with QML frontend and Python backend -

i want create qml module python "backend" if makes sense. basically, want use qml define how component looks, , implement specific behavior in python class, should extend qml-type , - in imagination - somehow must linkable qml component.

i understand how create custom class in python , making available qml via qmlregistertype. works far, drawing has implemented in class - no qml

(basically, want simliar way done in kivy kv-language)

a small example:

i implemented simple colorpicker widget this:

class colorwheel(qlabel):     radius = 0      color_changed = pyqtsignal(float, float)      def __init__(self, width, height):         super().__init__()          pixmap = qpixmap("colorwheel.png").scaled(width, height)          self.setfixedsize(width, height)         self.setpixmap(pixmap)         self.radius = width / 2      def mousereleaseevent(self, event):         # {...} mouse position, calc polar corrdinates (omitted)         # emit signal: new color selected         self.color_changed.emit(r, angle)      def get_polar(self, x, y):         # {...} calculate polar coordinates hsv color space (omitted)         return r, theta 

now want move gui-code (pixmap-drawing , on) qml file colorwheel.qml this:

import qtquick 2.0 item {     image {         id: img         anchors.fill: parent         source: "./colorwheel.png"       } } 

in main qml file main.qml want this:

import qtquick 2.2 import colorwheel 1.0  applicationwindow {     title: qstr("test invoke")     width: 500     height: 400      colorwheel {         radius: 200     } } 

is possible? not find in qt , pyqt documentation. it's making c++ classes available qml or other way around...

can point me in right direction?

many thanks!

if inherit qquickitem , register - act item {}.

if add properties on c++/python side - it'll item properties.

colorwheelimpl.h (make python equivalent):

class colorwheelimpl: public qquickitem { ... }; 

colorwheel.qml:

import qtquick 2.0 colorwheelimpl {     image {         id: img         anchors.fill: parent         source: "./colorwheel.png"       } }