Hello everybody! I’m a beginner at processing (but I have some experience with p5js and PJs).
I’m trying to find a way to assign a function to a variable. Essentially, I want to be able to set a function to a separate variable, and whenever that function is called, it calls my new function (which was defined by that variable)
Here’s the code I’m working with:
class button{
float posx,posy,widt,heig;
int buttonColor = color(0,0,0);
boolean customFunc; //I've tried void, int, and bool. Nothing wants to work.
button(float x, float y, float wid, float hei, int bColor, boolean func){
posx = x;
posy = y;
widt = wid;
heig = hei;
buttonColor = bColor;
customFunc = func; //HERE IS ANOTHER THINGY
}
void clickDet(){
if(mouseX >= posx && mouseX <= posx+widt && mouseY >= posy && mouseY <= posy+heig){
if(mouseButton1Click==1){
println("CLICKED ME!");
//HERE
}
}
}
I can’t find a way to do this easily. I know I could use an array/list, but that wouldn’t be very efficient in the long run. I also don’t want to really assign each button a custom ID (but I probably will anyway for debugging).
I’ve made code for buttons using the JavaScript ports, but I can’t get anything to work here. Please help me out here guys!
EDIT: Here’s the code for my JavaScript buttons:
var button = function(config){
this.x = config.x || 25;
this.y = config.y || 25;
this.w = config.w || 40;
this.h = config.h || 25;
this.textblack = config.tb || false;
this.textlabel = config.label || "button";
this.activate = config.activate || function(){}; //THIS IS WHAT I'M TRYING TO GET TO WORK IN PROCESSING
this.chosenfont = config.tfont || "arial";
this.textsiz = config.tsize || 10;
};
button.prototype.clickdet = function(){
return mouseX >= this.x && mouseX <= (this.x + this.w) && mouseY >= this.y && mouseY <= (this.y + this.h) && mouse.clicked.m1;
};
button.prototype.draw = function() {
if(this.clickdet()){
buttonlog.push("PRESSED BUTTON" + this.textlabel);
this.activate(); //THIS IS WHAT I WANT TO DO IN PROCESSING
}
rect(this.x,this.y,this.w,this.h);
if(this.textblack === true){
fill(0);
} else{fill(255);}
textFont(this.chosenfont,this.textsiz);
text(this.textlabel,this.x+this.w/6,this.y+this.h/2.5);
};
Not quite what I’m looking for, although this could be useful. I’m trying to pass a function that will be changed, as I am creating a button object/class to be used throughout my project.
In essence I’m trying to create a button object that can be called like this:
button startButton = new button(x,y,width,height,color,function);
and when clicked, it runs the ‘function’ argument. (In essence, do the javascript thing of storing a function inside of a variable)
I know that I could use that as my method for running the functions inside of each button object that I create, but it seems like a lot of extra work and I want to optimize it.
As opposed to writing the function to a switch statement, then assigning an ID to the button, I want to be able to assign a function to the button using the built-in argument passer.
Basically I want to be able to use a function as a variable. (And one that does not return anything {at least usually})
OK, I found a way that works, but I didn’t want to use it. I take advantage of the switch statement’s speed at finding addresses inside of an index. By using this, I can call it each frame without (hopefully) affected performance too badly.
int buttonFunctionIdManager = 0;
void button_Management(){
switch(buttonFunctionIdManager){
case 0: //DO NOTHIGN
break;
case 1: //DO SOMETHING NOT RESERVED
print("WE FIRED IT");
bFix();
break;
default:
println("[13]ERROR SOMEONE DID A BAD FUNCTION CALL: "+str(buttonFunctionIdManager));
bFix();
break;
}
}
button startGameButton = new button(25,25,25,25,3,color(250,0,255),color(0,255,255),"EYOOO");
I would have preferred to just assign a function to each button in the constructor, but yeah I can’t seem to figure that out.
This will require me to assign each function into the switch statement and to add the bFix(); function to reset it after every call. So in others words, more work is needed for the same amount of reward.
This is called a delegate: delegates are used to pass methods as arguments to other methods. Java doesn’t support this.
What you can do instead is use an interface; assign the button an instance of the interface, then call the methods against the interface.
For example, the ControlP5 library supports adding a callBackListener to a UI element. When the UI element is clicked/changes value, it calls the relevant method implemented in the user’s callback listener. Perhaps you’re looking to do something similar (call some method when the button is pressed for example).
