Support image animations (GIF, PNG)

[Cologler]

No description provided.

[inukshuk]

Where would you want the animations to play? Only in the image viewer or everywhere?

[Cologler]

I prefer everywhere.

[flachware]

Preserving animations sounds good to me. In the item table/grid some kind of interaction should be needed (hover or selection) to start the animation. In the image viewer we should consider adding a start/stop toggle to the toolbar at least.

[inukshuk]

There's an official plugin for GIF https://github.com/pixijs/gif

It parses the GIF using a gifuct-js. So this would not easily extend to PNG animations.

Instead we could save each frame separately using vips and load them into an animated sprite.