How to "load" library into a module

Hi there,

I intend to use the Glightbox module. As mentioned in this issues thread, when used as a node field formatter, the module does not format the images in the node view per se but create a "lightbox" pop-up once an image is clicked.

I  am trying to write a module called Glightbox_Justify which will "justify" the images in the node using the JustifiedGallery plugin. The module will depend on Glightbox because I still want to have the "lightbox" pop-up as well. There are Backdrop modules doing similar things but only as a view plugin (such as Masonry Gallery, Views Photo Gird, and Mosaic Grid).

The idea is

• to use the JustifiedGallery plugin to format the display. I used the hook_library_info().
• "alter" the display format configuration of Glightbox, using the hook_field_formatter_info_alter() in order to expose a form, using the hook_field_formatter_settings_form_alter(), so that people can enter their preferred row height (in px) of the image in the node content. 

That is what I did so far. After enabling the module I could see the field where I can enter the desired row height (framed in red). you can have a look at the code at https://github.com/hajarimanitra/glightbox_justify

I can install and activate my custom module Glightbox_Justify but it does not do what it is intended for. When I create a node with mutliple image, the images are not justified yet.  I think I still need to "activate" the js and css file from the library but I do not have any idea on how to do that.

So my questions are:

• Is the hook_library_info() enough for "loading" the library or do I still need to do something.
• How will I pass the value of the preferred image row height from the configuration to the js library (rowHeight variable, see the plugin documentation here)
• The css file in the plugin seems to act on a specific class (.justified-gallery), how will I attach that class to the wrapper to the images to be display in a justified format.

Thanks in advance,

Haja