Grayish overlay appears when scrolling, disappears if I rotate the device

[ollisulopuisto]

Hey y'all, take a quick look at this video: http://www.youtube.com/watch?v=yMwZUlI6ztQ

So basically what's happening is that the moment I start scrolling, a grayish overlay appears on the page. However, if I rotate the device and then return to the original orientation, the overlay disappears.

Using bundled mode, fresh install with book.json config that partly reads

"-baker-page-numbers-alpha": 0.01,
"-baker-rendering": "three-cards",
"-baker-background": "#ffffff",

Any idea what this might be about? I tried cleaning the emulator's screenshot directory, but maybe I missed something.

[folletto]

My first guess... It looks a transparency rendering bug. How are you setting the white background of your HTML? A CSS body rule?

[ollisulopuisto]

I'll check that out. I should mention that the same thing doesn't happen in Safari or Mobile Safari.

[folletto]

Yes, I'm aware. But unfortunately the UIWebView is and isn't Mobile Safari at the same time and we had to use some tricks (including making some components transparent) in order to try work around some bugs.

[ollisulopuisto]

Tried to strip out bits of the css (no body color rule, no transparencies left anymore) but it doesn't seem to have an effect.

Here's a second video that shows 1) how the overlay only covers a portion of a long page and 2) the debug messages in xcode: http://www.youtube.com/watch?v=AcYeMIx27vc&feature=youtu.be

[folletto]

Actually, you should do the opposite: ADD body color. Because by default the page is transparent. ;)

However, I really have no clue why that happens.

[ollisulopuisto]

That's it – adding an explicit body background color rule fixed it. Thanks.

Should we add a wiki page for these kind of known peculiarities? It's not quite a FAQ, but I could imagine someone else running into a similar program.

[folletto]

You're right, we should do something like that. :)

[ollisulopuisto]

Added a page https://github.com/Simbul/baker/wiki/Known-glitches-and-solutions . Feel free to rename it or move it to a better location.

[folletto]

Thanks, that's a good starting point. :)