creating (screenshot) galleries

[mark@…]

Trac is very handy for managing development projects. Yet it lacks some utility to create screenshot galleries.

The new "Image"-macro cannot be used to create such galleries, as nested macros are not supported. Thus you cannot write something like that to achieve an gallery-entry:

[http://somewhere/img/fullsize.jpg [[Image(thumbnail.jpg)]]]
[ArticleAboutThisImg]

Using HTML you are to directly link articles in the Wiki, which is very unelegant.

Therefore Trac misses something analog to Mediawiki's "gallery"-tag: ​http://en.wikipedia.org/wiki/Wikipedia:Picture_tutorial#New_MediaWiki_.3Cgallery.3E_tag

Syntax might be as follows:

[[ImageWithLink( <image>, <sizeofthumbnail>, <ArticleAboutThisImg)]]

Which then could be put in an ordinary table.

[Matthew Good]

The [[Image]] macro already supports a size argument and it links to the page with the full image just like Wikipedia.

For example:

[[Image(TracDev/ComponentArchitecture:comparch.png, 200)]]

[Emmanuel Blot]

Depending on the usage, this may not be optimum: The full image is sent by the server and resized by the browser, which brings several drawbacks:

• image quality is quite poor (nearest neightbour resizing)
• time to send a large image over the Internet
• server load

However, a server-side on-the-fly resizing is probably out of the scope of the image macro.

[mark@…]

Well, but it neither does link to corresponding article nor does it create the table for all the images, gallery alike.

[Christian Boos]

See also the related ​Gallery extension thread in the Mailing list.

The general idea being that the image shown in a gallery should be different (a thumbnail of) the image being linked to, and that Trac could assist in creating the thumbnails.

This seems related to the graph wiki processor idea that was discussed some time ago, and more precisely to the idea that there could be a cache for temporary files generated by wiki processors (see the ​Simple diagrams in Wiki thread)

[anonymous]

I've recently discovered the Python Image Library (PIL) and a snipplet for creating thumbnails. See ​http://www.daniweb.com/code/showsnippet.php?codeid=209.

If a caching folder was created (as wished in the GraphViz "simple diagrams in Wiki" thread) we can save the thumbnails there and have

[[ImageWithLink( [<image>, <sizeofthumbnail>, <ArticleAboutThisImg>, ...])]]

replaced with

<ul>
<li><a href="?Img?"><img src="?Thumbnail?" size="?SeeAbove?"></a><li>
...
</ul>

… for every entry. That way the gallery could be created.

[Christian Boos]

There's a ​TracHacks:GalleryPlugin, though it's not exactly covering the same need described here.

I rather think that #3567 covers the same ground.