PPS-23-CGE
Leonardo Randacio
I have worked indipendently on the View portion of the Engine.
The following is a detaild uml class diagram of the View:
Classes are colored based on the language used for implementation:
- blue : scala 3
- green : java 21
To implement the View using functional programming the State pattern is used.
State Pattern
The State implementation and it’s dependencies are present in the engine/view/monads directory.
Facade
To use the Java Swing library a SwingFunctionalFacade is implemented.
To limit the volume of Java code necessary the facade implements only basic atomic methods that are then used by the scala view portion of the project.
WindowState
The WindowState maps one-to-one all the methods of the java facade into State updates.
It also defines a Window type alias that simply replaces the Frame type, native to Java Swing.
This object removes the possible dependency from the specific Java GUI library being used.
GameView
The GameView singleton defines high level methods that the Controller can use to generate updates to the View’s State.
Every method returns a State[Window, Unit] so that it may be called by the Controller as part of a for-yield construct to compose the initial state of the View.
CardView
The cards are rappresented in the GUI using buttons.
If a card button is pressed it triggers an event structured as follows:
"<playerName>:<rank> <suit>"
Where:
- <playerName> is the name of the player that has that card in it’s hand;
- <rank> is the rank of the card;
- <suit> is the suit of the card.
ButtonView
The clearPanel method uses the List.foldLeft() method to build a state update composed by states removing one-by-one very button present in the given panel.
A val unitState(): State[Window, Unit] is defined that rappresents a state that keeps track of the current window but does not apply any update to it, in other words it is a state that “does nothing”.
def clearPanel(panelName: String): State[Window, Unit] =
panelButtons.get(panelName) match
case Some(buttons) =>
panelButtons = panelButtons - panelName
// Using List.foldLeft().
buttons.foldLeft(unitState()): (acc, button) =>
// Removing every button, prepending the state obtained by the previous button removal.
for
_ <- acc
_ <- WindowState.removeComponentFromPanel(panelName, button)
_ <- WindowState.removeButton(button)
yield ()
case None => unitState()