# Creating simple GUI to change variables in script
**URL:** https://discourse.processing.org/t/creating-simple-gui-to-change-variables-in-script/37912
**Category:** Libraries
**Created:** [July 10, 2022, 11:41pm UTC](https://discourse.processing.org/t/creating-simple-gui-to-change-variables-in-script/37912 "2022-07-10T23:41:22Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@NikhilPundir](https://discourse.processing.org/u/NikhilPundir)
#### Post date: [July 10, 2022, 11:41pm UTC](https://discourse.processing.org/t/creating-simple-gui-to-change-variables-in-script/37912/1 "2022-07-10T23:41:22Z")
I wanted to know if its possible to create a simple GUI to change different variables in the script and Re-Re-Render the image. Currently, I change a variable then run the program again to see result. A GUI to see instant change will save a lot of time. So is it possible easily ?
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### Author:  [@svan](https://discourse.processing.org/u/svan)
#### Post date: [July 11, 2022, 12:37am UTC](https://discourse.processing.org/t/creating-simple-gui-to-change-variables-in-script/37912/2 "2022-07-11T00:37:57Z")
> [@NikhilPundir](#):
>
> I change a variable then run the program again to see result
Please post the program.
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### Author:  [@Chrisir](https://discourse.processing.org/u/Chrisir)
#### Post date: [July 11, 2022, 10:02am UTC](https://discourse.processing.org/t/creating-simple-gui-to-change-variables-in-script/37912/3 "2022-07-11T10:02:38Z")
There are libraries that can provide buttons.
g4p or controlp5
They come with lot of examples
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### Author:  [@NikhilPundir](https://discourse.processing.org/u/NikhilPundir)
#### Post date: [July 12, 2022, 3:47am UTC](https://discourse.processing.org/t/creating-simple-gui-to-change-variables-in-script/37912/4 "2022-07-12T03:47:32Z")
Thanks a lot, I am looking into controlp5. Also, I am looking for behavior as shown in image - there are 2 windows, first small window for controls and the other for design preview. Are you aware of any library to achieve such behavior. I think its possible from controlp5 but I am still investigating how to achieve that.
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### Author:  [@svan](https://discourse.processing.org/u/svan)
#### Post date: [July 12, 2022, 5:58am UTC](https://discourse.processing.org/t/creating-simple-gui-to-change-variables-in-script/37912/5 "2022-07-12T05:58:03Z")
The source code below will allow you to create two windows controlled by a single sketch: a default Processing window for your controls and a PApplet window that could be used for graphics. Pulling the slider in the default window will change the size of the circle in the graphic window.
```auto
import controlP5.*;
ControlP5 cp5;
int radius = 50;
GraphicWindow wnd;
void setup() {
size(400, 250);
surface.setTitle("Default Window");
cp5 = new ControlP5(this);
cp5.addSlider("radius")
.setPosition(100, 50)
.setSize(200, 20)
.setRange(5, 255)
;
wnd = new GraphicWindow();
}
void draw() {
}
void mousePressed() {
println("mousePressed in default window");
}
class GraphicWindow extends PApplet {
public GraphicWindow() {
PApplet.runSketch(new String[] {this.getClass().getSimpleName()}, this);
}
void settings() { // Necessary for PApplet
size(300, 300);
}
void setup() {
}
void draw() {
background(150);
fill(0, 255, 0);
circle(width/2, height/2, radius);
}
void mousePressed() {
println("mousePressed in graphic window");
}
}
```
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### Author:  [@quark](https://discourse.processing.org/u/quark)
#### Post date: [July 12, 2022, 1:26pm UTC](https://discourse.processing.org/t/creating-simple-gui-to-change-variables-in-script/37912/6 "2022-07-12T13:26:13Z")
**G4P** also supports multiple windows. Also there is the **GUI Builder** tool which provides a visual design tool to create G4P GUIs including the creation of a control window. Both _G4P_ and **GUI Builder** can be installed using Processing’s Contribution Manager
More information about **G4P** and **GUI Builder** can be found on this [website](http://www.lagers.org.uk/) in particular
[G4P](http://www.lagers.org.uk/g4p/index.html) library info
[GUI Builder](http://www.lagers.org.uk/g4p/index.html) including some [videos](http://www.lagers.org.uk/g4ptool/v1-introduction.html) on how to use it.