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extend class (Read 1315 times)
tazumi
extend class
Jul 22nd, 2006, 1:49pm  
hi,

maybe a stupid mistake but i have problems to extend a class..
i have not much experience in java / processing oop.


public class myButton extends MyGUIButton {
   
 public myButton(processing.core.PApplet root, int x, int y)
 {
   super.MyGUIButton(root, x, y);
 }
}

error:
120:3: Semantic Error: No applicable overload was found for a constructor with signature "MyGUIButton()" in type "mkv.MyGUI.MyGUIButton". Perhaps you wanted the overloaded version "MyGUIButton(processing.core.PApplet $1, int $2, int $3);" instead?

the constructor exists with these arguments..

maybe someone can help me?

thanks, tazumi
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stevecooley
Re: extend class
Reply #1 - Jul 22nd, 2006, 10:01pm  
I'm in a similar situation. I have a function I've written that I was to extend pgraphics2 with, and I get the same error.
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chandler
Re: extend class
Reply #2 - Jul 23rd, 2006, 9:03am  
just call super() not super.MyGUIButton()

class Foo
{
 String name;
 Foo(String aname) {
   name = aname;
 }
 
 void printName() {
   println(name);
 }
}

class Bar extends Foo
{
 Bar(String aname) {
   super(aname);
 }
}

Foo f = new Foo("Steve");
f.printName();


Bar b = new Bar("ima bar");
b.printName();
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tazumi
Re: extend class
Reply #3 - Jul 23rd, 2006, 12:41pm  
hi,

thanks a lot.. it works fine.

cheers
tazumi
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stevecooley
Re: extend class
Reply #4 - Jul 23rd, 2006, 7:14pm  
Ok, I'm not having any luck, I'd love some help...

Quote:


int counter;
int arc_start_x;
int arc_start_y;
int arc_height;
int random_height;


//  this won't work because myClass is extending PGraphics2, which takes 3 arguments to construct,
//  so this applet will launch, but fail because it's missing arguments
// myClass big = new myClass();

// this doesn't work because it won't find my extensions to pgraphics2 .. I'm so confused.
myClass big = new myClass(2000,2000,null);

// this will work but will fail on calling my function, obviously
// PGraphics2 big = new PGraphics2(2000,2000,null);


void setup() {

 //  so, shouldn't I be doing something in the setup after object construction to set these arguments as defaults?
 // big.height1(2000);
 // big.width1(2000);

 big.background(128);
 big.defaults();
 big.smooth();  

}

void draw()
{
 int randomNumber = int(random(width));
 for(int x=0;x<=2;x++)
 {

   // uncomment these, and they work fine because they're not in the class extension.
   big.stroke(int(random(255)),int(random(255)),100);  
   big.line(counter*10, randomNumber, int(random(2000)), int(random(2000)));
   int arc_start_x = int(random(2000));
   int arc_start_y = int(random(2000));
   int arc_height = int(random(1900,1900));

   // BONK...
   big.myFunction(arc_height, arc_start_x, arc_start_y);

 }
 // etc..


 counter++;
 if(counter >= 100)
 {
   //  big.endFrame();
   // make sure the file is written to the sketch folder
   String path = savePath("big-"+int(random(100000000,1000000000))+".png");
   big.save(path);  
   noLoop();

 }
}



class myClass extends PGraphics2
{

 void myFunction(int arc_height, int arc_start_x, int arc_start_y)
 {
   arc_height = abs(arc_height);
   arc(arc_start_x, arc_start_y, arc_height, arc_height, TWO_PI-PI/2, TWO_PI);

 }

}
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stevecooley
Re: extend class
Reply #5 - Jul 23rd, 2006, 8:10pm  
Ok, so to be clear, my goal here is to create sketches  using my own functions inside large files that I can save to disk.

So, I got it to stop complaining about nullPointerException on the setup object function calls, by extending PGraphics instead of PGraphics2, but... now I can't save the image because that's in PGraphics2, I'm guessing.

Quote:


int counter;
int arc_start_x;
int arc_start_y;
int arc_height;
int random_height;



//  this won't work because myClass is extending PGraphics2, which takes 3 arguments to construct,
//  so this applet will launch, but fail because it's missing arguments
myClass big = new myClass();

// this doesn't work because it won't find my extensions to pgraphics2 .. I'm so confused.
// myClass big = new myClass(2000,2000,null);

// this will work but will fail on calling my function, obviously
// PGraphics2 big = new PGraphics2(2000,2000,null);


void setup() {

 //  so, shouldn't I be doing something in the setup after object construction to set these arguments as defaults?
 // big.height1(2000);
 // big.width1(2000);

 big.background(128);
 big.defaults();
 big.smooth();  

}

void draw()
{
 int randomNumber = int(random(width));
 for(int x=0;x<=2;x++)
 {

   // uncomment these, and they work fine because they're not in the class extension.
   big.stroke(int(random(255)),int(random(255)),100);  
   big.line(counter*10, randomNumber, int(random(2000)), int(random(2000)));
   int arc_start_x = int(random(2000));
   int arc_start_y = int(random(2000));
   int arc_height = int(random(1900,1900));

   // BONK...
   big.myFunction(arc_height, arc_start_x, arc_start_y);

 }
 // etc..


 counter++;
 if(counter >= 100)
 {
   //  big.endFrame();
   // make sure the file is written to the sketch folder
   String path = savePath("big-"+int(random(100000000,1000000000))+".png");
   big.save(path);  
   noLoop();

 }
}



class myClass extends PGraphics
{

 int height1 = 2000;
 int width1 = 2000;


 void myFunction(int arc_height, int arc_start_x, int arc_start_y)
 {
   arc_height = abs(arc_height);
   arc(arc_start_x, arc_start_y, arc_height, arc_height, TWO_PI-PI/2, TWO_PI);

 }

}





here's the error

Quote:
java.lang.RuntimeException: Error while saving image.

at processing.core.PImage.save(PImage.java:2215)

at Temporary_271_588.draw(Temporary_271_588.java:57)

at processing.core.PApplet.handleDisplay(PApplet.java:1336)

at processing.core.PGraphics.requestDisplay(PGraphics.java:535)

at processing.core.PApplet.run(PApplet.java:1152)

at java.lang.Thread.run(Thread.java:613)


because the save function is in PGraphics2, not PGraphics, yeah?  How do I extend PGraphics2 and construct an object without parameters?  
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tazumi
Re: extend class
Reply #6 - Jul 25th, 2006, 11:01am  
i am not sure but you do not call de constructor of the base class(?)


class myClass extends PGraphics2
{  
 // constructor of extended class, calls the constructor
 // of the base class (with fixed arguments)
 myClass()
 {
   super(arg1, arg1, arg3)
 }
 
 // alternative with arguments to pass to the base      
 // constructor
 myClass(int arg1, int arg2, int arg3)
 {
   super(arg1, arg1, arg3)
 }


 void myFunction(int arc_height, int arc_start_x, int arc_start_y)
 {
   //...

 }
}

someone correct me if i am wrong..
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stevecooley
Re: extend class
Reply #7 - Jul 25th, 2006, 9:34pm  
OH, create the PGrapics2 object inside my function? I will definitely need to poke around that idea.. thank you for the tip!
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stevecooley
Re: extend class
Reply #8 - Jul 25th, 2006, 11:14pm  
Well, I'm getting not the same type of problem now.  Inside of my class it appears to be valid to create a PGraphics2 object, thereby invoking the constructor with the valid arguments...  but now I'm having a problem on saving...


Quote:


int counter;
int arc_start_x;
int arc_start_y;
int arc_height;
int random_height;

// Ok, so this is the new deal... call PGraphics2 inside of my class?
myClass big = new myClass();

void setup() {
 big.background(128);
 big.defaults();
 big.smooth();  
}

void draw()
{
 int randomNumber = int(random(width));
 for(int x=0;x<=2;x++)
 {

   // uncomment these, and they work fine because they're not in the class extension.
   big.stroke(int(random(255)),int(random(255)),100);  
   big.line(counter*10, randomNumber, int(random(2000)), int(random(2000)));

   int arc_start_x = int(random(2000));
   int arc_start_y = int(random(2000));
   int arc_height = int(random(1900,1900));

   // working? can't tell.
   big.myFunction();

   arc_height = abs(arc_height);
   big.arc(arc_start_x, arc_start_y, arc_height, arc_height, TWO_PI-PI/2, TWO_PI);

 }

 counter++;
 if(counter >= 100)
 {
   // big.endFrame();
   // make sure the file is written to the sketch folder
   String path = savePath("big-"+int(random(100000000,1000000000))+".png");
   big.save(path);  
   noLoop();

 }
}

class myClass extends PGraphics
{
 // things seem to be working better with this... except saving the file doesn't work. :-\
 PGraphics2 big = new PGraphics2(2000,2000,null);

 void myFunction()
 {

   big.stroke(int(random(255)),int(random(255)),100);  
   big.line(counter*10, int(random(200)), int(random(2000)), int(random(2000)));

 }

}






error message:

Quote:
java.lang.RuntimeException: Error while saving image.

at processing.core.PImage.save(PImage.java:2215)

at Temporary_4897_7142.draw(Temporary_4897_7142.java:49)

at processing.core.PApplet.handleDisplay(PApplet.java:1336)

at processing.core.PGraphics.requestDisplay(PGraphics.java:535)

at processing.core.PApplet.run(PApplet.java:1152)

at java.lang.Thread.run(Thread.java:613)



ok, I thought it could be that I was trying to extend PGraphics instead of PGraphics2.  Here's the error message when I change "extends PGraphics" to "extends PGraphics2":

Quote:
java.lang.NullPointerException

at processing.core.PGraphics2.clear(PGraphics2.java:932)

at processing.core.PGraphics.background(PGraphics.java:3279)

at Temporary_1601_2818.setup(Temporary_1601_2818.java:12)

at processing.core.PApplet.handleDisplay(PApplet.java:1269)

at processing.core.PGraphics.requestDisplay(PGraphics.java:535)

at processing.core.PApplet.run(PApplet.java:1152)

at java.lang.Thread.run(Thread.java:613)
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fry
Re: extend class
Reply #9 - Jul 26th, 2006, 3:10pm  
to back up a bit, i don't understand what you're trying to do. it doesn't sound like you need to subclass PGraphics or PGraphics2 at all, but rather that you want to either 1) just do a sketch with size(bignumber, bignumber) and call saveFrame() to save its contents. or, you should use createGraphics(), as described in the faq:
http://processing.org/faq/advanced.html#big
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stevecooley
Re: extend class
Reply #10 - Jul 26th, 2006, 8:56pm  
I have a function that I've written that draws a specific compound 2d mark... I could omit this step and just throw all the code into the draw() routine, as I've done here:

http://www.somejunkwelike.com/gallery/main.php?g2_itemId=34383&g2_imageViewsIndex=2

But, I was trying to get my head around some more OOP... Thanks for the additional tip, I'll give createGraphics() a try... hopefully next time this thread floats up, it will be because I figured it out.
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