Data classes

Each time we create a model class, we end up writing the same boilerplate code for:

• Constructor
• Getter-Setter (s)
• hashCode()
• equals()
• toString()

Kotlin introduced the  data keyword where the compiler automatically derives the following stuff based upon the parameters of the primary constructor:

• Getter-Setter (s), which are not technically due to data keywords
• equals()/hashCode() pair
• toString()
• componentN() functions corresponding to the properties in their order of declaration
• copy() function

It saves a lot of boilerplate code and makes the model classes look clean and concise.

The Message class is the data structure representing the messages left by a user on the map. It holds the actual message left, the author of the message and location (coordinates) of the message on the map:

    /**
      * It represents the message shown on the maps
      */
    data class Message(
    // The message
    var content: String,
    // Location of the message
    var location: Point? = null,
    var id: Int? = null
    )