No sure to understand what you mean but as you set height and width attributes, this gives a fixed size for the image and by default it is centered inside the available space. To remove the center, normally you should set the xalign, yalign and xexpand, yexpand attributes.
The dimensions of the image widget are defined in height and width attributes of the containing field node as mentioned in Large image preview of binary field in the form. When I choose the dimensions of the image fitting the available space, then on both sides margins/paddings are added as in Now screenshot above. This added margins/paddings disappearing when window gets smaller on resize. Yet I have no clue wherefrom these margins/paddings come and how to avoid them if possible.
OK, I’ll give it a try. Nevertheless, I would prefer not to redefine the elements of the whole column.
Maybe it’s a lack of my understanding of tryton/gtk GUI composition. From my point of view it’s the image widget causing the layout distortion, when disabled the layout behaves as expected:
The default dimension values for the image widget are defined in image.py as height = 100, width = 300.
Using GtkInspector I’m pretty sure it’s the Gtk’s image widget making some trouble. After tracing and debugging the steps of image creation and displaying, it looks like somehow the creation of the image from the pixbuf in Image.update_img is messed up. The steps before specially the resize of pixbuf runs as expected.