CBZ/CBR thumbnail support

[rudexi]

Hi team,

I'd like to suggest the support of thumbnails for CBZ/CBR formats (for comic/manga).
For format itself is a simple zip/rar file, containing images, and renamed into .cbz/.cbr, respectively.
Usually, most explorers supporting it display the first image found in the archive (by alphabetic order).

So far on Windows explorer, I was using this project to display CBZ thumbnails
https://github.com/T800G/CBXShell

I have some experience on Rust and Typescript, so I'm willing to work on it. I'd just need some hints on how to add a new thumbnail format.

[utkubakir]

Great idea!

@fogodev would be your guy for the hints. I also recommend joining our discord server for easier communication :)

[fogodev]

Here, in this function, we dispatch an appropriate handler for the desired extension. So I think that to support it we only need to create a new handler here, and then pass the new extensions to be allowed in the thumbnailer.

spacedrive/crates/images/src/handler.rs

Lines 29 to 67 in 4447820

	fn match_to_handler(ext: Option<&OsStr>) -> Result<Box<dyn ImageHandler>> {
	let ext = ext.map(OsStr::to_ascii_lowercase).unwrap_or_default();
	let mut handler: Option<Box<dyn ImageHandler>> = None;
	if consts::GENERIC_EXTENSIONS
	.iter()
	.map(OsString::from)
	.any(|x| x == ext)
	{
	handler = Some(Box::new(GenericHandler {}));
	}
	#[cfg(feature = "heif")]
	if consts::HEIF_EXTENSIONS
	.iter()
	.map(OsString::from)
	.any(|x| x == ext)
	{
	handler = Some(Box::new(HeifHandler {}));
	}
	if consts::SVG_EXTENSIONS
	.iter()
	.map(OsString::from)
	.any(|x| x == ext)
	{
	handler = Some(Box::new(SvgHandler {}));
	}
	if consts::PDF_EXTENSIONS
	.iter()
	.map(OsString::from)
	.any(|x| x == ext)
	{
	handler = Some(Box::new(PdfHandler {}));
	}
	handler.ok_or(Error::Unsupported)
	}

[fogodev]

Feel free to reach me out on discord for any further explanations

[rudexi]

Thank you, will take a look at the code and come back to you on discord when I need further details.