Force visually distinguishable account colors

[skjnldsv]

Divide the hue value by 20, round it and multiply it again by 20.
This allows for (360/20) 18 differents colors.

@jancborchardt
Fix #1428

[mention-bot]

By analyzing the blame information on this pull request, we identified @ChristophWurst, @Gomez and @jancborchardt to be potential reviewers

[jancborchardt]

Hmm … either the value is too low or it’s not working. The colors are still very difficult to distinguish.

One is hsl(140, 60%, 68%) and the other hsl(160, 60%, 68%). Maybe let’s increase the distance initially to 30 or 40? If there’s more, we can still fill up inbetween.

[skjnldsv]

The calcul is simple, if we divide by 40, we get (360/40) 9 different colors! And it's just a random possibility, the chance we get 2 exact same colors are as high as any other one.
If you really want a different color we should not use the core generator.

Or we should allow the user to change the hash we're using to generate the color therefore allow him to change the color he wants (but we keep the randomisation)

[jancborchardt]

The point is that the feel of the colors across ownCloud should be similar. So I would say we need to use the generator here.

Let's maybe increase it to 30 to see if that works better? Or have a separate function for multi-color request with a variable amount of parameters – and the function ensures they are as distinct as possible.

[skjnldsv]

I feel like doing some terrible coding! :p
I'm gonna do some screenshot of the different colors for 30 and 40 :)

[skjnldsv]

Here you go: 20, 30 and 40.

[jancborchardt]

Niice – yeah, that illustrates very well that we need the 40 value. With 30 still some green/turquoise and the rightmost pink colors are difficult to distinguish.

[skjnldsv]

Got it :)

[skjnldsv]

Here you go! @jancborchardt !
But keep in mind that doesn't mean you will get different colors! You could very well get 3 times the same! There's a very poor chance, but still ;)

[jancborchardt]

Yeah, this is better! :)

About the different colors, that’s why I suggested above:

Or have a separate function for multi-color request with a variable amount of parameters – and the function ensures they are as distinct as possible.

And simply taking from the set of 9 above. That would be quite useful already for the multiple mail accounts and the calendar colors. :)

[ChristophWurst]

tztztz… failing CI tests and @jancborchardt hits the merge button

[jancborchardt]

I AM JUST MACHINE TAKING ORDERS

SEE MERGE BUTTON

HIT IT

[skjnldsv]

ahahahahhaha