WebPositive: glitch with native UI elements

[miqlas]

Some website uses non-skinned ui elements like dropboxes, buttons, checkboxes, etc. WebPositive shows them correctly, but if one scrolls the webpage, the UI elements looses their fill color. Using the scrollbar one can see how the fill-color stays in place.

[miqlas]

This is hrev54886 x86_64 Haiku, but as far as i remember it was always so.

[pulkomandy]

I thought this had been reported already but can't find it. I had investigated a bit and there is some incorrect interaction between scrolling and clipping. The clipping used in BControlLook does not take the scrolling into account and thinks parts of the drawing are outside the visible region, when clearly they are not.

However I didn't fully understand it or managed to reproduce it outside of webpages

[X512]

It is probably caused by using regions in BControlLook implementation that do not support transforms. Also same problem is present when clipping to rectangle sometimes because it is internally handled as region.

[X512]

However I didn't fully understand it or managed to reproduce it outside of webpages

Just apply affine transforms to BControlLook drawings and bad things will happen. It is not only clipping issues, but also control drawing that depends on pixel hinting will stop working when affine transform is applied.

​PictureView can be used for experiments. Code can be easily adjusted to draw BControlLook controls.