I believe there may be a bug in efl.evas_object_image.pxi.image_data_set()

[jockm]

Disclaimer:. I am very new to EFL and doubly so Python-EFL, but I had a program where I was trying to update the image data of an image control.

So I cobbled together some code that looked like this:

    def updateImage(self, imageControl, rgbaImage):
        w, h = rgbaImage.size
        d = rgbaImage.tobytes()

        evas_image = imageControl
        evas_image.image_size_set(w, h)
        evas_image.image_data_set(d)

        # Force the Evas image to reload and display the new data
        evas_image.image_data_update_add(0, 0, w, h)
        imageControl.show()

and the line evas_image.image_data_set(d) would throw and exception that would read:

ValueError: buffer size (1) is smaller than expected (7680000)!

So I dug into the code on github and in efl.evas_object_image.pxi, in the method .image_data_set() we see this code:

expected_size = _data_size_get(self.obj)
        if view.itemsize < expected_size:
            raise ValueError(
                "buffer size (%d) is smaller than expected (%d)!" % (
                    view.itemsize, expected_size
                    )
                )

Where we see view.itemsize being compared against expected_size. However the documentation for itemsize says:

Item size in bytes of a single element.

Thus view.itemsize will always be smaller than the size of the whole buffer, and always throw an exception.

Now it's completely possible I am misunderstanding what you pass into to image_data_set(), but the documentation in not the most clear