Java8 using enum values in interface's default methods

enums, interface, java, java-8

Solution

The problem is your architecture. On the one hand, you have a layer that actually executes the mouse-movement (represented by your `Robot` interface). Now, you need a layer that produces mouse-movement and sends it to a `Robot` to execute this mouse-movement. Let's call the interface defining this layer `MouseTarget` (fits your example nicely):

public interface MouseTarget {
    int getTargetX();
    int getTargetY();

    default void moveMouseHere(Robot robot) {
        robot.moveMouse(this.getTargetX(), this.getTargetY());
    }
}

This interface represents one mouse-movement to one target. As you see the `moveMouseHere(Robot robot)` method expects a `Robot` to send the movement to (which does the actual work). Now, all what is left is to adapt your `Fields` enum:

public enum Fields implements MouseTarget {

    AGE_FIELD(778, 232), NAME_FIELD(662, 280);

    public int targetX;
    public int targetY;

    Fields(int targetX, int targetY) {
        this.targetX = targetX;
        this.targetY = targetY;
    }

    @Override
    public int getTargetX() {
        return targetX;
    }

    @Override
    public int getTargetY() {
        return targetY;
    }
}

Problem

I'm exploring possibilities of static and default methods introduced in java 8. I've an interface that has 2 default methods that do construct a command, that I run on server through ssh to do some simple tasks remotely. Moving mouse requires 2 arguments: x and y position of the mouse. ``` public interface Robot { default String moveMouse(int x, int y) { return constructCmd("java -jar move_mouse.jar " + x + " " + y); } default String clickLeft() { return constructCmd("java -jar click_left.jar"); } static String constructCmd(String cmd) { return "export DISPLAY=:1.0\n" + "cd Desktop\n" + cmd; } } ``` I've multiple enums with values preset, I could potently combine all enums into one and not use interface what so ever, however that enum would contain hundreds or thousands of values and I want to keep it somewhat organised, so I've split evertying in multiple enums. I want all enums to share same methods so I figured I'll give default methods in an interface a shot. ``` public enum Field implements Robot { AGE_FIELD(778, 232), NAME_FIELD(662, 280); public int x; public int y; Field(int x, int y) { this.x = x; this.y = y; } } ``` So I can get String commands by: ``` Field.AGE_FIELD.clickLeft(); Field.AGE_FIELD.moveMouse(Field.AGE_FIELD.x, Field.AGE_FIELD.y); ``` However moveMouse looks really bad to me and I think it should be somehow possible to use enum's values by default. Anyone has a a nice solution for such problem?

Original source