Hi,

Is it possible to show a JFileChooser (from javax.swing)  in a PApplet?

My code is something like the showed down and sometimes it works, but sometimes the JFileChooser doesn't load well (when the mouse is over them just when it is showed or when the button is pressed).
Maybe I need to config an event listener or something like that but how?? thank you very much.

public void openFile()
{
 File f = null;
 JFileChooser selector = new JFileChooser(".");
 try
 {
   int value = selector.showOpenDialog(null);
   if( value == JFileChooser.APPROVE_OPTION)
   {
     f = selector.getSelectedFile();
   }

   println("file selected: "+f.getAbsolutePath() );

 }
 catch(Exception e)
 {
   e.printStackTrace();
 }
}

Or even better, just check Processinghacks.com:

http://www.processinghacks.com/hacks/filechooser

OK, had a brain wave about event despatching threads and so on.  If you use invokeLater from the SwingUtilities, your applet will continue running in the background and you shouldn't get any strange side effects from showing the JFileChooser:

Code:

void mousePressed() { 

  SwingUtilities.invokeLater(new Runnable() {
    public void run() {
	try {

	  JFileChooser fc = new JFileChooser();
	  int returnVal = fc.showOpenDialog(null);

	  if (returnVal == JFileChooser.APPROVE_OPTION) {
	    File file = fc.getSelectedFile();
	    String lines[] = loadStrings(file); // loadStrings can take a Java File Object too
	    for (int i = 0; i < lines.length; i++) {
		println(lines[i]); 
	    }
	  } 
	  else {
	    println("Open command cancelled by user.");
	  }
	}
	catch (Exception e) {
	  e.printStackTrace();
	}
    }
  });
  
}

 

If you use this method for something real (not just printing lines from a file!) you'll want to set a boolean or something to say when the file is loaded, and check that inside draw.

Having trouble writing some all purpose file browser functions. I want to be able to call a function returning a PImage or null. I can't setup a local variable in the function to return the information though. I get:
Code:

Semantic Error: Invalid reference in inner class "Temporary_3524_5415$1" to a non-final local variable, "temp", declared in method "getFile".
 

I can patch this however:
Code:

import javax.swing.*;
PImage pimage;
PImage temp = null;
void setup(){
  size(200,200);
}
void draw(){
}
void mousePressed(){
  pimage = getFile();
  if(pimage != null){
    image(pimage, 0, 0, width, height);
  }
}
PImage getFile(){
  //PImage temp = null;
  SwingUtilities.invokeLater(new Runnable() {
    public void run() {
	try {
	  JFileChooser fc = new JFileChooser();
	  int returnVal = fc.showOpenDialog(null);
	  if (returnVal == JFileChooser.APPROVE_OPTION) {
	    File file = fc.getSelectedFile();
	    boolean executeOperation = false;
	    if(file.getName().endsWith("jpg") || file.getName().endsWith("gif")){
		temp = loadImage(file.getPath());

	    }
	  }
	}
	catch (Exception e) {
	  e.printStackTrace();
	}
    }
  }
  );
  return temp;
}
 

But that means I have to have a global variable floating around that I may have to empty each time I call the function. Which looks a teeny bit unsightly, and goes against the idea of having an encapsulated function that I can copy from sketch to sketch. Is there a solution to this problem?

Okay. I've knocked up a workaround that is a lot simpler than my previous attempt. Plus it accounts for the fact that the fileChooser runs a little asynchronous to the mother applet.
Code:

import javax.swing.*;
PImage pimage;
String getFile = null;
void setup(){
  size(200,200);
}
void draw(){
  if(getFile != null){
    fileLoader();
  }
}
void mousePressed(){
  getFile = getFileName();
}
void fileLoader(){
  String ext = getFile.substring(getFile.lastIndexOf('.') + 1);
  ext.toLowerCase();
  if(ext.equals("jpg") || ext.equals("gif")){
    pimage = loadImage(getFile);
    image(pimage, 0, 0, width, height);
  }
  getFile = null;
}
String getFileName(){
  SwingUtilities.invokeLater(new Runnable() {
    public void run() {
	try {
	  JFileChooser fc = new JFileChooser();
	  int returnVal = fc.showOpenDialog(null);
	  if (returnVal == JFileChooser.APPROVE_OPTION) {
	    File file = fc.getSelectedFile();
	    getFile = file.getPath();
	  }
	}
	catch (Exception e) {
	  e.printStackTrace();
	}
    }
  }
  );
  return getFile;
}
 

I imagine there might be some cleverer way of doing this (please tell if there is) but I'm happy for now. Thanks.

It does work actually. I generally try to test code before posting it because my code point blank never works on the first draft. Before the return information is sent the String getFile is set. My problem related to the fact I have several file operations I wanted to go about doing. I wanted to be clever and have it all in one function, but I think you're right that I've gone about it in a pretty complicated fashion. It's my patch the patch coding style I'm afraid. I'll write it nicer in future.

To wrap up I guess, the data being loaded by the file chooser needs to be global to the applet. For my sketch I included an extra option to set whether it loads or saves (returnVal = fc.showSaveDialog(null);) I'll mention for anyone else trying this that the information you pass to the file chooser function needs to be final. eg:
Code:

fileChooser(final boolean isOpenDialog){
  //yadda yadda
}
 

But it doesn't need to be final outside the function. So the file name filter stuff will just need final tagged in front of it.

Works fine on every machine at anytime.

Until I export it. Then it only works on PCs.

In your version you assign an image in the other thread, and in mine I assign a String. I get the fact that having a return value is ridiculous, that's something I blatantly overlooked. Is it the fact that the function has a returnable value that means it shouldn't work?

The annoying thing is that this code is all embedded in a project using the AIExport library, which does funny stuff to Processing's "folder" variable. So I'm beyond making concrete examples.

Heyo, resurrecting an old one here....

Fry's method works great, in terms of the file chooser coming up without problems and all, but after the chooser goes away I'm not getting keyPressed calls anymore. Any idea why that might be?

I do continue to get mousePressed calls.