[PyQt] PyQt5 fails to handle QQuickImageProvider subclassing

[Julio César Gázquez]

El 04/01/17 a las 16:17, Phil Thompson escribió:
>> ImageProvider supports Image type but has not implemented requestImage()
>>
>> Seems this message comes from Qt's QQuickImageProvider::requestImage() implementation, so it's like the C++ method isn't being overridden by the PyQt's wrapper method.
>>
>> These methods are somewhat peculiar, as they are virtual methods (and specifically meant to be subclassed) and have an /Out/ parameter. Doing a grep on the PyQt sources I see this only happens in two places outside this class. Maybe the wrapper for the virtual method lacks the /Out/ parameter?
>>
>>
> Try it, just pip install the latest version into a venv.
No, I'm afraid it doesn't work even with 5.7.1 (via pip install on 
Ubuntu Xenial):

julio at marte:~/devel/test$ python3 test.py
ImageProvider supports Image type but has not implemented requestImage()
file:///home/julio/devel/test/test.qml:3:1: QML Image: Failed to get 
image from provider: image://images/any.jpg

> Otherwise I would need a short complete example that demonstrates the problem.
>
Minimal test example below.

test.py:

from PyQt5.QtCore import QUrl, Qt
from PyQt5.QtGui import QGuiApplication, QImage
from PyQt5.QtQuick import QQuickView, QQuickImageProvider


class ImageProvider(QQuickImageProvider):

     def __init__(self):
         super().__init__(QQuickImageProvider.Image)

     def requestImage(self, id_, requestedSize):
         """ Just a red image """
         image = QImage(requestedSize.width(), requestedSize.height())
         image.fill(Qt.red)
         return image, requestedSize


class Application(QGuiApplication):

     def __init__(self, argv):
         super().__init__(argv)
         self._view = QQuickView()
         self._view.engine().addImageProvider("images", ImageProvider())
         self._view.setSource(QUrl.fromLocalFile("test.qml"))
         self._view.show()


if __name__ == '__main__':
     app = Application([])
     app.exec_()


test.qml:

import QtQuick 2.1

Image {
     width: 400
     height: 300
     source: "image://images/any.jpg"
}

TIA.

Greetings, Julio.