Method addMouseHandler

src/main/java/field/graphics/Window.java:689–692

A keyboard handler is a Function , Boolean>>, that is a function that takes a transition between two MouseStates and returns a boolean, whether or not it ever wants to be called again

(Function<Event<MouseState>, Boolean> h)

        if ((after.mods & GLFW_MOD_CONTROL) != 0)
            after.keyboardState = after.keyboardState.withKey(GLFW_KEY_LEFT_CONTROL, true);
        else after.keyboardState = after.keyboardState.withKey(GLFW_KEY_LEFT_CONTROL, false)
                .withKey(GLFW_KEY_RIGHT_CONTROL, false);
        if ((after.mods & GLFW_MOD_ALT) != 0)
            after.keyboardState = after.keyboardState.withKey(GLFW_KEY_LEFT_ALT, true);
        else after.keyboardState = after.keyboardState.withKey(GLFW_KEY_LEFT_ALT, false)
                .withKey(GLFW_KEY_RIGHT_ALT, false);
        if ((after.mods & GLFW_MOD_SUPER) != 0)