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Claw76
Claw76 wrote ...

2019/1/30

Can somebody tell me if this is good?

Claw76 Claw76

2019/1/30

#
This is my idea for a Button class and I wanted to know if it is a good idea. I saw some ideas how to create Buttons, but nobody never really came up with a solution like this (as far as I know). However, I also wanted to know if there are improvements that could be made and if there is a way that the Button class doesn't need to inherit from the Actor class. Please reply. This is the code from the Button class:
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import greenfoot.*;
/**
 * It creates an object where you can click on.
 *
 * @author Claw76
 * @version 30.01.2019
 */
public class Button extends Actor
{
    private GreenfootImage unclickedImg;
    private GreenfootImage clickedImg;
    private GreenfootImage standardUnclickedImg = new GreenfootImage("unclickedbuttonstandard.png");
    private GreenfootImage standardClickedImg= new GreenfootImage("clickedbuttonstandard.png");
    public Button()
    {
        setUnclickedImg(standardUnclickedImg);
        setClickedImg(standardClickedImg);
        setImage(unclickedImg);
    }
 
    public void act()
    {
 
    }
 
    public boolean buttonClicked() //returns "True if Button is clicked and "False" if not
    {  
        boolean isClicked=false;
        if(!Greenfoot.mousePressed(this))
        {  
            setImage(unclickedImg);
            Greenfoot.delay(4);
            isClicked=false;
        }
        else if(Greenfoot.mouseClicked(this))
        {
            setImage(clickedImg);
            isClicked=true;
        }
        return isClicked;
    }
 
    public void setUnclickedImg(GreenfootImage img)
    {
        unclickedImg = img;
    }
 
    public void setClickedImg(GreenfootImage img)
    {
        clickedImg = img;
    }
 
}
This is the subclass where you basically just perform the "buttonClicked" method in an if-condition to execute the method you want, when the button is clicked. I tested it with the "addObject" method: There was something missing:
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import greenfoot.*;  // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)
 
/**
 * Its just an Test object of the Button class.
 *
 * @author Claw76
 * @version 30.01.2019
 *
 */
public class TestButton extends Button
{
    /**
     * Act - do whatever the TestButton wants to do. This method is called whenever
     * the 'Act' or 'Run' button gets pressed in the environment.
     */
    public void act()
    {
        if(buttonClicked())
        {
            //write the methods you want to execute when the button is clicked here
            getWorld().addObject(new Button(), 300, 300);
            Greenfoot.delay(2);
        }
    }   
}
At the moment you need to add the Button Object in the your World class, because if you first add a button object and then run your scenario the button will execute the method directly even when you didn't click the button. Additionally, sometimes when you click the button nothing happens. Maybe somebody can tell me how to fix this. (I use this Button class in another scenario where it works perfectly fine so...)
danpost danpost

2019/1/30

#
Claw76 wrote...
This is my idea for a Button class and I wanted to know if it is a good idea. I saw some ideas how to create Buttons, but nobody never really came up with a solution like this (as far as I know). However, I also wanted to know if there are improvements that could be made and if there is a way that the Button class doesn't need to inherit from the Actor class. Please reply. This is the code from the Button class: << Code Omitted >>
As far as inheriting Actor, you will need an Actor object to display the button in greenfoot unless you modify the background image of the world. As far as improvements, there are fields, variables and methods that are totally unnecessary. The following should be equivalent:
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import greenfoot.*;
 
public class Button extends Actor
{
    private GreenfootImage unclickedImg = new GreenfootImage("unclickedbuttonstandard.png");
    private GreenfootImage clickedImg = new GreenfootImage("clickedbuttonstandard.png");
     
    public Button()
    {
        setImage(unclickedImg);
    }
     
    public void act { }
     
    public boolean buttonClicked()
    {
        if (Greenfoot.mouseClicked(this))
        {
            setImage(clickedImg);
            Greenfoot.delay(4);
            return true;
        }
        if (!Greenfoot.mousePressed(this))
        {
            setImage(unclickedImg);
        }
        return false;
    }
}
I am not sure if you are losing mouse action during the delay. It might be best to removed it and add a timer for how long the clicked image shows. This would also eliminate the need for checking the mouse pressed state:
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import greenfoot.*;
 
public class Button extends Actor
{
    private GreenfootImage unclickedImg = new GreenfootImage("unclickedbuttonstandard.png");
    private GreenfootImage clickedImg = new GreenfootImage("clickedbuttonstandard.png");
    private int timer;
     
    public Button()
    {
        setImage(unclickedImg);
    }
     
    public void act() { }
     
    public boolean buttonClicked()
    {
        if (Greenfoot.mouseClicked(this))
        {
            setImage(clickedImg);
            timer = 4;
            return true;
        }
        if (timer > 0 && --timer == 0) setImage(unclickedImg);
        return false;
    }
}
This is the subclass where you basically just perform the "buttonClicked" method in an if-condition to execute the method you want, when the button is clicked. I tested it with the "addObject" method: There was something missing: << Code Omitted >> At the moment you need to add the Button Object in the your World class, because if you first add a button object and then run your scenario the button will execute the method directly even when you didn't click the button. Additionally, sometimes when you click the button nothing happens. Maybe somebody can tell me how to fix this. (I use this Button class in another scenario where it works perfectly fine so...)
Some or all of this may be fixed by the above change. However, I do not get adding a new Button object (which will not have its buttonClicked method executed) into the world. Maybe just what you decided to do for the test. I, myself, will always use System.out.println for testing purposes. That way I can usually be a bit more informed about what is happening. Also, here again, you should probably avoid using Greenfoot.delay. It does have its uses, but I do not thing here is one of them.
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