/oop-java-fx

Primary LanguageJava

Tiny Math

Task description

Your goal is to write simple UI application that would allow you to solve math equations. We want to reuse our model of calculations that was designed a few weeks ago and try to use it in the context of UI application. We want to have:

  • +, -, * and / binary operations
  • cos, sin and ln unary operations
  • numbers (in the UI we can limit ourselves to single digit so possible input will be numbers 0-9)
  • single variable x
  • derivative operation
  • value in specified point operation
  • placeholder to wait for user input (showing whitespace in the UI and throwing exception when actually used instead of being replaced by actual operation)

Your task is to:

  1. Write a model for this application that will be independent of the UI. It should be placed in separate package (e.g. pl.edu.mimuw.model) and should have at least 3 tests in DerivativeTest class.

  2. Write UI for the model. The UI may contain buttons for operations, digits, variable and calculation of the derivative and function value. We can simplify our approach here by restricting user to input his function in specified way - he needs to build the math expression as tree, so for example, to input cos(x * x) + ln(x) he would need to click

    1. +
    2. Build Left
    3. cos
    4. Build child
    5. *
    6. Build Left
    7. x
    8. Left Done
    9. Build Right
    10. x
    11. Right Done
    12. Child Done
    13. Left Done
    14. Build Right
    15. ln
    16. Build Child
    17. x
    18. Child Done
    19. Right Done

    where we need to use our placeholder for yet not-built child in tree representation and allow go through the tree structure with extra buttons Build Left, Build Right, Build Child, Left Done, Right Done, Child Done. Of course, if you can think of some simpler/better input method for this kind of expressions, you can design them using your own idea.

Hints

  • first let's take a look at last commit introducing this task to see what is needed to work with JavaFX application in Gradle project - you can find it here.
  • you can find sample app in Main class - it creates an application with some buttons and text area which are properly aligned and have some actions assigned to them.
  • ou should start your application with run task. As usual, you can start it from console with 
    ./gradlew run
    but also you can run it from IDE by clicking Ctrl twice and inputting gradlew run as task name - this will create extra run configuration in the IDE, and you'll be able to run your app with green triangle button in top-right corner (as well as debug your application).
  • be aware of Java version used in this task (there is some mess in terms of JavaFX) - I used Java 11 and it worked well, so start with checking the File/Project structure settings if you have the same version.
  • don't forget about providing required unit tests of your model to show me that you already know how to write these tests.
  • feel free to ask questions as there may be new things - here you can find a good description and examples of the usage of JavaFX - let's take a look there to find some new controls for your application.