The easiest way would be to create a 1D array of strings from the 2D array of GTextField objects using the getText() option then use saveStrings() to save the string array to a single file. Use loadStrings() to read the string array from disc and re-populate the GTextField objects with setText(). You can use G4P.selectInput and G4P.selectOutput to get in/out dialog boxes. These are easier to program with than those in Processing 2.0 because they work in the main execution thread.

The actual implementation of this should be fairly straightforward, if you want further advice I would need to know

• Am I correct that you have a 2D array of GTextField objects e.g. GTextField[][]?
• What happens to the GTextField in a row that is deleted - are they dipsosed of or made invisible or what?
• What version of Processing and G4P are you using?

In programming, for non-trivial tasks, there is rarely a "best" way...
You can do as quarks said, relying on data position to restore it (PS.: data is already a plural word, singular, rarely used, is datum; that's something that tripped me too ), CSV style. It is probably the simplest way.
Now, depending on your needs, you can make a file in Json or XML style, or even in .ini style, using Yaml, etc.

But here, since data seems to have no hierarchy, CSV (or TSV) can be a good solution, indeed.

Yes what I'm using is a 2D Array.
a line of 7 fields, when 'erased' is setVisible(false), and a counter is decreased, same counter I use to create a new line.
So i thougth I could use the same counter to choose which strings to save. when I reload a file, in the file there should be also a way to know how many lines are saved/should be created.

said that, I'm trying this method, but i find difficult to translate my GTextField[][] 2D Array, to a String[] to make saveStrings() work..

what I did is:

1. void SavePrg() {
     for (int i = 0; i < lineCnt; i++) {
       for (int colCnt = 0; colCnt < 7; colCnt++) {
         stringToSave[(i*7)+colCnt] = PrgLineTFlds[i][colCnt].getText();
       }
     }
     saveStrings("SavedFile.txt", stringToSave);
   }
   
   

and the error is:

1. ################  EXCEPTION IN EVENT HANDLER  ################
   An error occured during execution of the eventhandler:
   CLASS: MC_KD1_v005   METHOD: handleButtonEvents
       Caused by java.lang.NullPointerException
       MC_KD1_v005.SavePrg(MC_KD1_v005.java:957)
       MC_KD1_v005.handleButtonEvents(MC_KD1_v005.java:642)
       sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
       sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
       sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
       java.lang.reflect.Method.invoke(Method.java:597)
       g4p_controls.GAbstractControl.fireEvent(Unknown Source)
       g4p_controls.GButton.mouseEvent(Unknown Source)
       g4p_controls.GWindowInfo.mouseEvent(Unknown Source)
       sun.reflect.GeneratedMethodAccessor8.invoke(Unknown Source)
       sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
       java.lang.reflect.Method.invoke(Method.java:597)
       processing.core.PApplet$RegisteredMethods.handle(PApplet.java:1084)
       processing.core.PApplet.handleMethods(PApplet.java:1279)
       processing.core.PApplet.handleMouseEvent(PApplet.java:2560)
       processing.core.PApplet.dequeueEvents(PApplet.java:2463)
       processing.core.PApplet.handleDraw(PApplet.java:2153)
       processing.core.PGraphicsJava2D.requestDraw(PGraphicsJava2D.java:193)
       processing.core.PApplet.run(PApplet.java:2020)
       java.lang.Thread.run(Thread.java:662)
   ##############################################################
   
   

any suggestion?

Thanks, Davide.

EDIT:
Ops, sorry, I forgot to give the array a dimension:
String[] stringToSave = new String[150];

Quarks, I couldn't find an example for G4P.selectInput and G4P.selectOutput.
can you suggest?

thanks.

EDIT:
I've found this: http://www.lagers.org.uk/g4p/applets/g4p_dialogs/index.html
but if I take the code and save it under my Linux PC it doesn't work, giving me this error:

The function selectFolder(String) does not exist.

I'm Using Processing v.2.0b7.
G4P: prettyVersion=3.0.0 .......... I've just seen that new versions are out, sorry.
going to download 3.2 and try that again!

Thanks, Davide.

EDIT 2:
...and yes, it runs as expected...
Thanks again.

I've a question on the G4P.SelectInput/Output.
Is there a way to choose the initial path in the dialog? now it opens on my user path, but I would like it to be in the executable path.

is it possible?

Thanks, Daide.