Add icon for zeal

[cweiske]

Zeal requires the docset icon to be at

• Contents/Resources/Documents/favicon.ico
• Contents/Resources/Documents/icon.png

The RFC docset does not show an icon in Zeal because there is no image at the listed locations.
See zealdocs/zeal#186

[willnorris]

I added an icon in e2ea7ec. I'm waiting to hear back on zealdocs/zeal#186 as to whether zeal will load icons from this location in the docset.

[willnorris]

According to zealdocs/zeal#186 (comment), zeal should be consistent with Dash in terms of icon handling. Could you test that out with the latest v1.2 release?

[trollixx]

icon.png should be 16x16 to be displayed correctly. 32x32 icon should be named icon@2x.png. On non high resolution displays 16x16 is used everywhere, while 32x32 would cause unnecessary slowdown due to resizing.

See https://github.com/Kapeli/Dash-X-Platform-Resources/tree/master/docset_icons for standard Dash icons as an example.

[willnorris]

I'm working off of Dash's docs, which make no mention of @2x icons: https://kapeli.com/docsets#addingicon

I think CPUs can handle resizing a 32px image to 16px without "unnecessary slowdown".

[trollixx]

No idea how noticeable slow down could be :) That document is not clear enough about hi-res situation. It does say it's highly recommended that you provide the exact size (16x16 and 32x32). I think it's a minor issue, but perhaps @Kapeli could clarify what is the best option for PNG icons?

[Kapeli]

The slow down is minor. That notice is there because I've seen some docsets with really really large icons (e.g. 2048x2048).

However, I do mention what you should do for @2x icons already:

For Retina-display support, use a multi-resolution TIFF (with the sizes 16x16 and 32x32), or a 32x32 PNG.

So a 32x32 PNG is fine. Also you can add 2 separate icons: icon.png and icon@2x.png.

Was your confusion because of the use of Retina? It's the same as @2x. Should I clarify all mentions of Retina to be @2x?

[trollixx]

@Kapeli It would be nice to explicitly say how PNG icons should be named, because @2x thing is not that well-known outside of OS X/iOS world yet.

Zeal expects icon.png to be 16x16, then it automatically tries to use icon@2x.png when run on a High-DPI screen. Also, Zeal doesn't support multi-page TIFF icons due to lack of such feature in Qt.

[Kapeli]

Great. I'll add the naming details and I'll remove the mention of TIFFs. I was against TIFFs anyways as they're hard to create.

[cweiske]

Icon shows fine in Zeal 0.6.0.

[weppos]

Closing as per @cweiske's comment. Please reopen if it's still an issue.