Description

Gallery and Image Management

The Gallery Tool is designed to work in concert with the Resource Tool. This allows both instructors and students to create folders that represent "collections" of images to be viewed using the Gallery Tool. While collections defined by the Content Hosting Service (CHS) could be tagged in some way as "collection folders", it's not clear that such is needed. An alternative approach would be to treat all such collections as potential image collecitons and handle the case where there are no images present, perhaps with an error message. As such, filtering of non-gallery collections could be avoided.

The Resource Tool provides several means to upload images into a collection: singlely, multiply, zipped, and via WebDAV. Once in place, access permissions can be specified, release and retraction dates defined, and order imposed. Note that some of these operations are not enabled by default in the Sakai 2.3 release.

Definition of Terms

Image
A resource who's content type is a member of the list defined by the Gallery Tool, usually one of the image MIME types such as image/jpeg, image/tiff, image/png, etc.

Image Collection
A resource collection who's members are all images. Image Collections have a property that defines the representative image to be display when showing the collection as an entity.

Gallery
A set of image collections group into a resource collection. Initially, there will only be one of these either hard-named to "Galleries" or identified by the user.

Use Cases

Instructors

1. Create collection
2. Organize images within a collection
3. Organize collections (within the gallery) by subject, class session, ?????
4. Assign students a collection for review (for an exam for instance)
5. Assign students an image for review
6. Assign students a certain group of images (may come from a variety of collections) for review (all images of Frank Lloyd Wright's early work from the semester for instance)
7. See what students see

Students

1. Find a particular image and see details for review
2. Find a collection and review it
3. Browse collections in the course
4. Study for an upcoming exam (review course images)
5. Find image(s) for an assignment

Once we have a solid design to support the primary goal, we can start thinking about how we might be able to tweak things to support the secondary goal if time, resources, etc. allow.

To be clear, I'm not assuming that users will be able to complete each activity (use case) above in the system (and likely they won't). To understand the user's experience though I like to think through how the set of activities that help meet the goal will be affected by the system. So, for instance, for "assign students an image for review"... it's not likely we'll support the "assignment" of the image but understanding the complete activity will help me understand the experience without thinking about the gallery tool as a silo. It will also help me get real with trade-offs. Already this list reminds me how much we will be depending on the resources tool and the ability for users to create their collections in meaningful ways via the Resources tool.

Viewing and Sequencing

The Gallery tool provides five main functions at this time:

1. Navigate to an image-collection.
2. View and edit metadata associated with an image-collection.
3. View the image-collection as an array of thumbnails.
4. View an image full sized, perhaps in a pop-up window.
5. View the image-collection sequentially, perhaps in a pop-up window.

When an image is displayed full size, it should include it's name and description text (if any). It may be possible, when a single image is select for display, to jump into the sequence for that image. That would allow the user to then move back and forth in the sequence and see near by images (etc).

Images are defined to be of a certain mime type. At this time, these types are restricted to image/gif, image/jepg, and image/png. Perhaps supported image types could be system configurable. A desire for other media types, including video has been expressed.

Gallery Tool Design

The application is considered to have four main states:

1. Navigation
2. Collection Metadata
3. Collection Thumbnails
4. Image View (and sequencing)

transitions are navigation or selection clicks:

Gallery Tool Services

Traditional Sakai tool design calls for the creation of an application service that encapsulates the business logic. A simple gallery service is proposed that would be layered over the Content Hosting service.

GalleryService

The GalleryService provides management of galleries:

1. Get the list of image-collections in the gallery.
2. Find an image-collection by id
3. Get image-collection information
4. Set image-collection information

Creation of and editing of image-collections is deferred.

ImageCollection

The ImageCollection object represents an ordered set of images, mapped onto a ContentHosting collection. It must provide the following capabilities:

1. Get id
2. Get reference
3. Get an image by id
4. Get an image by reference
5. Get an ordered list of images
6. Get representative image id
7. Set representative iamge id
8. Get next image
9. Get previous image
10. Get nth image