How to return an image

Question

so basically i am creating a gameboard using javafx and i have a cell state class that returns a character value at the moment depending on whats in the cell. So basically if the cell is empty it returns ' ' , if i has a player in it it returns '@' and so on for different cell states. i was just wondering how i could return an image instead of characters.

public class Cell {

    CellState cellState;

    public Cell(CellState newCellState) {
        cellState = newCellState;
    }

    public CellState getCellState() {
        return cellState;
    }

    public void setCellState(CellState newCellState)
    {
        cellState = newCellState;
    }

    public char displayCellState()
    {
        return getCellStateCharacter(cellState);
    }

    public char getCellStateCharacter(CellState newCellState)
    {
        switch (newCellState)
        {
        case EMPTY:
            return ' ';
        case PLAYER:
            return '@';
        case MONSTER:
            return '&';
        case POISON:
            return '*';
        case BLOCKED:
            return '#';
        default:
            return ' ';
        }

    }


 }

MY CELL STATE CLASS

    public enum CellState
    {
    EMPTY,
    PLAYER,
    MONSTER,
    POISON,
    BLOCKED
    };



public class GameBoard {
static final int BOARD_WIDTH = 10;
static final int BOARD_HEIGHT = 10;

Cell[][] boardCells;
int width;
int height;

public GameBoard()
{
    boardCells = new Cell[BOARD_WIDTH][BOARD_HEIGHT];

    width = BOARD_WIDTH;
    height = BOARD_HEIGHT;
}

public void initGameBoard()
{
    for (int i = 0; i < height; ++i)
    {
        for (int j = 0; j < width; ++j)
        {
            boardCells[j][i] = new Cell(CellState.EMPTY);
        }
    }

    boardCells[0][0].setCellState(CellState.PLAYER);

    boardCells[2][4].setCellState(CellState.MONSTER);
    boardCells[2][6].setCellState(CellState.MONSTER);

    boardCells[7][8].setCellState(CellState.POISON);

    boardCells[5][0].setCellState(CellState.BLOCKED);
    boardCells[5][1].setCellState(CellState.BLOCKED);
    boardCells[5][2].setCellState(CellState.BLOCKED);
    boardCells[5][3].setCellState(CellState.BLOCKED);

}

public String displayBoard()
{
    String output = "";
    output +="| |";
    for (int i = 0; i < width; ++i)
    {
        output +=i + "|";
    }
    output +="\n";

    for (int j = 0; j < height; ++j)
    {
        output +="|" + j + "|";
        for (int k = 0; k < width; ++k)
        {
            output +=boardCells[k][j].displayCellState() + "|";
        }
        output +="\n";

    }

    return output;
}

}

Answer 1

enums are classes too. So as the CellState enum is representing your states, probably best to encode all of the relevant info for a given state straight into the CellState class. That would include the character and the image.

import javafx.scene.image.Image;

public enum CellState {
   EMPTY(' ', "empty.png"),
   PLAYER('@', "player.png"),
   MONSTER('&', "monster.png"),
   POISON('*', "poison.png"),
   BLOCKED('#', "blocked.png");

   private final char cellChar;
   private final Image cellImage;

   CellState(char cellChar, String imageLoc) {
     this.cellChar = cellChar;
     this.image = new Image(imageLoc);
   }

   public char getChar() {
     return cellChar;
   }

   public Image getImage() {
     return cellImage;
   }

   @Override
   public String toString() {
     return Character.toString(cellChar);
   }
}

Then you keep your cell API as before, but you can drop the getCellStateCharacter() method and replace its usage with cell.getCellState().getChar(), and similarly for image it would be cell.getCellState().getImage().

To understand where the Image constructor gets the image from, see:

• Where does javafx.scene.image.Image("flower.png") look for flower.png?

If you want to get an image from the classpath (e.g. when the image is packaged in a jar), you can use:

new Image(getClass().getResourceAsStream("player.png"))

The above will fetch the image from the same folder in the classpath where the CellState.class file is located.

Answer 2

I guess you can use byte array for image returning, and then show it on screen