Full documentation is conveniently provided directly from the add_on add/edit interface but here it is again:

Picture & Thumbnail size

Images will never be scaled up in size (i.e. an image smaller than the given size settings will not be enlarged).

If cropping, the width and height determine the exact size of the resized image.

If not cropping, the image is resized proportionally, so width and height determine the maximum possible size.

Setting a width or height to 0 means 'ignore this size in our calculations' (as opposed to 'make this invisible'):

if cropping, setting one dimension to 0 means that only the other dimension will be cropped.
if not cropping, setting one dimension to 0 means that the image will be scaled down proportionally according to the other dimension.
if both width and height are set to 0, resizing/cropping will be disabled for that size. (Do this if you're not using a particular size of image in your template.)

Display order

The display order can be the fileset order or random.

Fileset order: The thumbnails will appear as they were ordered in the fileset. As of Concrete 5.4.1 you can order pictures in a fileset any way you like (see below).

Random order: The thumbnails will appear in a different order every time the page is accessed. Ideal for a dynamic feel.

How to re-order images

Files can be manually re-ordered in a file set. (many thanks to user Deoldphart for this one)

For C5 5.4.1

• In the dashboard click on "File manager" in the left hand menu
• At the top, click on the tab that says "Sets"
• Click on the set you want to order
• Drag and drop the files to order them
• Click on the button "Save display order"
• Go back to the page where your gallery is and reload
• In some rare cases you might have to put the gallery in edit mode and click save (no need to change any setting) to have the new file order apply)

For C5 5.5 & up

• In the dashboard under "Files" click on "File sets"
• Click on the set you want to order
• At the top, click on the tab that says "Files in Set"
• Drag and drop the files to order them
• Click on "Save"
• Go back to the page where your gallery is and reload
• In some rare cases you might have to put the gallery in edit mode and click save (no need to change any setting) to have the new file order apply)

Thumbnail captions & tooltips

The caption below each thumbnail as well as the tooltip that appears when hovering over the thumbnails are both taken directly from the 'Title' property each picture has in the fileset manager.

By default the 'Title' is set to the file name (file_name.jpg for instance) so we suggest you modify it to your liking.

Alternatively you could design a template and delete the whole '.touchgallery-thumbs a:after' selector in touchStyles.css. Doing so the thumbnails will appear without any caption.

We also suggest you check the comments at the beginning of the view.php file for a list of variables that offer added possibilities.

Keyboard navigation

In full-screen mode the gallery can be navigated using the keyboard.

Use the left and right arrows to go to the next/previous picture.

Us the esc key to close the slideshow.