Mini-Project 5: Augmentive and Alternative Communication Devices

Assigned

Wednesday, 28 February 2024

Summary

In this mini-project, you will use an extended version of the AssociativeArray class from the last mini-project to build a sample AAC.

Collaboration

Each student should submit their own responses to this project. You may consult other students in the class as you develop your solution. If you receive help from anyone, make sure to cite them in your responses.

In this mini-project, you will explore (a) the use of associative arrays and other kinds of maps, (b) programming to specifications in support of a larger project, (c) dealing with conflicting approaches to Java programming, and (d) considering some of the issues at play in designing software for people with disabilities (and using software as a disabled person).

The assignment

Do the assignment at https://accessibilityeducation.github.io/assignments/AAC/AAC.html, using your AssociativeArray class instead of HashMaps. Please leave your AssociativeArray and KVPair classes in the structures package, but copy that package into this project..

Recommended stages

To do this assignment, you should follow these steps, modifying them as you consider appropriate.

• Read the instructions and background.
• Fork and clone the repository at https://github.com/catiembaker/AACNestedHW.
• Remove the .project package from the repository.
• Add your structures package to the repository (presumably in src/structures).
• Create an AACCategory class with stub methods that follows the specifications given at https://accessibilityeducation.github.io/assignments/AAC/AACCategory.html.
  • Note that your AACCategory class will likely contain an AssociativeArray<String,String> that maps image locations (strings) to words (also strings).
• Create an AACMappings class with stub methods that follows the specifications given at https://accessibilityeducation.github.io/assignments/AAC/AACMappings.html.
  • Note that your AACMappings class will likely contain an AACCategory object that maps filenames to their corresponding words. You may also want an AssociativeArray<String,AACCategory> that maps either filenames or names to categories.
  • Sample stub versions of getImageLocs(), getText(String), and getCurrentCategory() follow.
• Run the application to get a basic sense of how it works (or should work).
  • Warning! At least on my computer, it takes a while to load.
• Start implementing methods.

Note that you will likely need to update AssociativeArray to support methods like getImageLocs().

Sample stub methods

  public String[] getImageLocs() {
    return new String[] { "img/food/icons8-french-fries-96.png", "img/food/icons8-watermelon-96.png" }; // STUB
  } // getImageLocs()

  public String getText(String imageLoc) {
    return "television";  // STUB
  }

  public String getCurrentCategory() {
    return "food";  // STUB
  }

Rubric

Redo or above

Submissions that fail to meet any of these requirements will get an I.

[ ] Includes the specified `.java` files, correctly named.  (They should
    be in the appropriate package.)
[ ] Each class has an introductory Javadoc comment that indicates
    the author and purpose. 
[ ] Includes a `README.md` file that contains the appropriate information 
    (authors, purpose, acknowledgements if appropriate)
[ ] All files compile correctly.

Meets expectations or above

Submissions that fail to meet any of these requirements but meet all previous requirements will receive an R.

[ ] Appears to follow Google Java style guidelines for indentation and such.
[ ] Appears to correctly load a file.
[ ] Appears to correctly add an image to the top-level category.
[ ] Appears to correctly switch to subcategories.
[ ] Successfully grabs words from subcategories.
[ ] Appears to correctly switch to the default screen.

Exemplary / Exceeds expectations

Submissions that fail to meet any of these requirements but meet all previous requirements will receive an M.

[ ] All (or most) repeated code has been factored out into individual 
    methods.  
[ ] All or most variable names are appropriate.
[ ] `AACCategory` and `AACMappings` do not access any fields in
    `AssociationList` or `KVPair`.

Q&A

How do we add new categories?

It seemed from the specs that categories are only created when you load the file upon creating a new AACMapppings. However, upon looking at the underlying code, I determined that any images on the default screen are considered categories.

I hear you also did this MP. What part did you find hardest?

Yes, I did this MP. I try to do most of them. I found writing a keys method for AssociationList the hardest part because creating arrays using generics is painful. I assume there’s a good way to do it, but I always find myself struggling.

How did you address the problem?

Since we only need an array of strings I was tempted to write at String[] keyNames method. However, that seemed like an easy out. If I were re-designing the assignment, I’d probably require that we provide an iterator for keys rather than an array of keys.

In the end, I used something similar to the mechanism I used in the constructor. That is, I used Arrays.newInstance using the first key in the pairs array to specify the type.

Of course, I couldn’t do that if I had no key/value pairs, so I returned null in that case, which complicated the implementation of getImages.

What else was difficult?

I didn’t see a natural way to write isCategory; it seemed much more natural to check if a word is a cateogry than if an image location is a category. I later discovered that they didn’t use isCategory and they assume any image on the home screen is a category.

Can I provide full path names to the images?

No. That’s not portable. You should write portable code.

Can I change the names of the images?

I’d prefer that you don’t change the names of the images. It may interfere with our testing.

The interface for adding image/text pairs seems fairly cumbersome, particularly for users with limited mobility.

I’d agree. Let’s assume that a friend or assistant would add them.

Why do you think our AACMappings class would benefit from a field of type AssociativeArray<String, AACCategory>?

You’ll need to keep track of the AACCategory for each image on the top-level page.

Why do you think our AACMappings class would benefit from a field of type AACCategory?

You’ll need to keep track of the location-to-name mappings somewhere. I think it’s easier if you use an AACCategory for uniformity.

More Q&A (from 2024Sp)

In the AACCategory class methods do we have to use getCategory to check if the image is in the category in the getImages, getText, and hasImage function or are we making an assumption that everything that we call in this class is part of the same category?

You do not need to use it to check if an image is in a particular category. Rather, we use it primarily in case the client code needs to identify the category (e.g., to speak it aloud).

We wil use it primarily to support the getCurrentCategory method in AACMappings.

In a hidden design issue, the UI looks for a category of "" to decide whether it’s working with the top level.

What might it entail to update AssociativeArray to support getImageLocs()? (That is, what might I want to keep in mind when I think about these changes?)

You’ll need to figure out how to return an array of keys. It can be hard to build a generic array, so you may want to build an array of the keys represented as strings.

Should AACCategory and AACMappings share an interface?

No. They have different responsibilities. (They also have some similar responsibilities, which complicates matters a bit.)

How do I relate category, text, and image together?

In AACMappings, you provide facilities for converting the path to an image to the corresponding category.

In AACCategory, you provide facilities for converting the path to an image to the corresponding word.

What do I do with the PNG files?

You’re only responsible for keeping track of the path to those files (and some corresponding information). The provided front end deals with displaying them.

If we’re mapping images to words with our arrays, how are we to associate those words with sounds? Or should our implementation not worry about playing sounds when we click on the pictures, just print the words.

You will return words. The provided code speaks them.

Should we use inheritance to implement the AACMapping class?

I would suggest using “wrapping” with a AssociativeArray field.

How should error handling be implemented for methods like getImageLocs() and getText() to handle cases where the requested image location or text is not found?

Welcome to one of the conflicts between how Dr. Baker designs things and how I do. You’ll need to figure out some other way to signal an error. (Ideally, there won’t be any.) For example, getText() might return "Not found" and getImageLocs() might return an empty array.