How to get mouse wheel listener on gui?

[SHsuperCM]

yet again.. with my mod....

 

i now have a GUI that has a list of strings that i want to scroll around it..

 

the thing i need is something like:

if(scroll up){
    int -= 1
}

and

if(scroll down){
    int += 1
}

[Choonster]

Call

org.lwjgl.input.Mouse#getEventDWheel

from your override of

GuiScreen#handleMouseInput

to get the scroll amount, if any.

 

I suggest looking at how vanilla and Forge use this in various GUI classes like

GuiScrollingList

or

GuiChat

.

[SHsuperCM]

thanks so much..

modified a bit the

handleMouseInput

from the

GuiChat

class.

why didnt i think of looking at that i dont know....

    public void handleMouseInput() throws IOException
    {
        super.handleMouseInput();
        int i = Mouse.getEventDWheel();

        if (i != 0)
        {
            if (i > 1)
            {
                i = 1;
            }

            if (i < -1)
            {
                i = -1;
            }

            recordsScroll += i;
        }
    }

ill tweak it a bit more after that to limit and such...

[Draco18s]

And then multiply by any value you want to make it go faster/slower.

[SHsuperCM]

And then multiply by any value you want to make it go faster/slower.

ye i was going to make it go faster anyway.. i just took the base

 

but

You can just do

int i = Integer.signum(Mouse.getEventDWheel());

and have the same effect as with all those if statements.

wowowowow signum? wth is signum? i never even heard a word that is looking like this word..

 

i think i like the normal code instead, where its more spread out on the method.. so later when i look at it i know what it does easly...

 

actually i do know signalum(http://ftbwiki.org/Signalum_Ingot) and it looks a bit like signum? rig;right? right? 

[SHsuperCM]

Signum is fancy-word for sign.

signum(i)

gives you -1 for negative numbers, +1 for positive numbers and 0 for 0.

just telling which side of the plate the number is? that's it? i wonder why mojang didnt use this..

in the source code it does then exactly what signum does..

[SHsuperCM]

so looked around java a bit online and realised how simple it is.. i just never used it...

 

it compacted the code way more..

    public void handleMouseInput() throws IOException{super.handleMouseInput();
        recordsScroll += Math.signum(Mouse.getEventDWheel());  //note to self(signum returns +1 for positive numbers and -1 for negative numbers, 0 for 0..)
    }

[SHsuperCM]

No, don't do Math.signum! It's for floating point numbers and compared to

Integer.signum

it's horribly slow. Plus, why are you even dealing with floating point?

oh oops.. tnx for letting me know...

and what u mean by floating point?

[SHsuperCM]

Floating Point.

 

In Java:

float

and

double

.

oh these ones.. where do i use them? i just changed math to integer im dont think im using floats or doubles anywhere, am i?

[SHsuperCM]

Math.signum

only exists in two versions where it takes a

double

or a

float

and it returns the same thing. There is no

int signum(int)

in

Math

, only

double signum(double)

and

float signum(float)

ok i understood it already.. i changed it to

Integer.signum