Make background colour switcher optional

[jancborchardt]

The background color switcher for transparent images is really not necessary. We should do it like Wikipedia and just insert the white-grey pattern background: https://en.wikipedia.org/wiki/Wikipedia#/media/File:Wikipedia-logo-v2.svg

[oparoz]

Unfortunately, that doesn't work with white content.

[jancborchardt]

This is how it looks in the Wikipedia viewer: https://commons.wikimedia.org/wiki/Category:White_logos?uselang=de#/media/File:Disqus_logo_%28white%29.svg
Indeed not ideal, but if we just increase the contrast of the white and grey, it will be nicely visible.

And even then, I would say if anything a background switcher like that should be a shortcut or something else, but not a prominent button like it is now. Because it really is an edge-case.

[oparoz]

We've had this discussion before :). Some people have folders filled with such content and the slideshow becomes useless if they can't present it in a decent way.

I thought about making the checkboard darker, but then things start looking strange, as it can interfere with darker images.

I'll just make the feature optional, via the config file first.

[deMattin]

Example Preview (example png with mixed transparent and solid)
with white background:

with black background:

This is, how it would look like with a pattern (simulated with photoshop, that uses this to show transparency):

The problem is, that you are only able to see the real looking of the transparent picture with switching.
I would even like to have a third color (grey or even colored) to circle through these backgrounds!
I like this background switching and when designing transparent graphics, I think, most people use different colored layers in working progress to check the looking of transparency.

With background switching, I am able to show you a graphic and you are able to assess it.
With a white/grey or single color background it's a matter of chance, if the picture is shown in an appropriate manner.

All in all: If you don't need this button, you are not forced to press it!
But if transparency isn't shown appropriate, you have to download the file and open it in a fitting graphics programm and preview is useless in his case.

Edit:
In above example, you see by switching, that "MK" isn't transparent as it should be!
With grey/white checkerboard you won't even see the "MK" if it also would be transparent ...

[jancborchardt]

All in all: If you don't need this button, you are not forced to press it!

@deMattin that’s not the point. It is there, and the majority of people don’t need it. I’m sure we can think of a more elegant solution here.

[deMattin]

I understand, why you don't like the button and also would like to have a solution without it.
But I have no idea (yet), how to solve this, without a button.

[oparoz]

There is one party trick I like, but which is not easy to implement because pictures may fill the screen. It's where you present to the user a "band" going from dark to light. The user clicks on the shade and it changes the background.

But the elegant solution is here anyway #84 :P

[deMattin]

Maybe I have an idea - not a real solution but a way to get rid of the button:

Clicking on the picture itself circles through background colors:
white - grey - black -...
So the button is not needed any more.

Ok, it's not intuitive, but if you have read the readme or by doing it accidently you will know about such a "hidden" feature ...

@oparoz Automatic feature is great but how do you know, that this automatic color stands for transparency?

[oparoz]

@deMattin I think it's not a bad idea to enable the change via a click and it's definitely something which can be tested for usability.

And the automatic feature does some calculations and based on the result picks either the white or black background. It can be extended of course to pick an exact shade, but I don't think it's worth it.

[deMattin]

@oparoz: In my above example you see, that a black background won't show that the "MK" isn't transparent as it should be. You only see this by switching to a grey or white background!
White background also is no good, because then you don't see the "clouds".

[oparoz]

Yeah, but those are details. The solution can use a light or a dark checkboard, clearly indicating where the picture is transparent.

[oparoz]

This could also already be implemented with the current switching solution.