How to open files from a directory, randomly?

Programming Questions

therjth

How to open files from a directory, randomly?

in Programming Questions • 5 months ago

Hi,

I connected my Processing 1.5.1 with my Arduino Uno. I've plugged in a button into my breadboard, which is connected to the Arduino.

My goal: if you press down the button, processing opens a bitmap file from a directory randomly. — I mean the route leads to a folder, that is filled with bitmap files, the processing picks one out and opens it in fullscreen.

This is how my code looks like now:

import processing.serial.*;
import cc.arduino.*;
Arduino arduino;
int buttonPin = 2; // the number of the pushbutton pin
int ledPin = 13; // the number of the LED pin // this is not solved yet.
int buttonState = 0;
void setup()
{
//println(Arduino.list());
arduino = new Arduino(this, Arduino.list()[6], 57600);
arduino.pinMode(ledPin, Arduino.OUTPUT);
arduino.pinMode(buttonPin, Arduino.INPUT);
}
void draw()
{
buttonState = arduino.digitalRead(buttonPin);
if (buttonState == arduino.HIGH) {
println("2013.pdf");
open("/Users/rjth/Desktop/2013.pdf");
}
else {
arduino.digitalWrite(ledPin, arduino.LOW); // this is not solved yet.
}
}

Is there any kind of way to do that? Thank you very much.

Replies(4)

ramin

Re: How to open files from a directory, randomly?

5 months ago

Hey,

here is a short example, how you can get a list of file and foldernames, which are in a folder:

import java.io.*;
File f = new File("C:/");
println(f);
String[] list = f.list();
for (String fileName : list)
println(fileName);

So if the folder only contains bmp files, you could do something like that

loadImage(list[list.length]);

to load a random image

therjth

Re: How to open files from a directory, randomly?

5 months ago

Ok, I've tried it out, It seems that I am close to the solution, but I still got an error message.

This is how the code looks like now:

import java.io.*;
File f = new File("/users/rjth/desktop/2013");
import processing.serial.*;
import cc.arduino.*;
Arduino arduino;
int buttonPin = 2; // the number of the pushbutton pin
int buttonState = 0;
void setup()
{
//println(Arduino.list());
arduino = new Arduino(this, Arduino.list()[6], 57600);
arduino.pinMode(buttonPin, Arduino.OUTPUT);
arduino.pinMode(buttonPin, Arduino.INPUT);
}
void draw()
{
buttonState = arduino.digitalRead(buttonPin);
if (buttonState == arduino.HIGH) {
println(f);
String[] list = f.list();
for (String fileName : list)
println(fileName);
loadImage(list[list.length]);
}
else {
arduino.digitalWrite(buttonPin, arduino.LOW);
}
}

and this is how the error message looks like:

Display 0 does not exist, using the default display instead.
Stable Library
=========================================
Native lib Version = RXTX-2.1-7
Java lib Version = RXTX-2.1-7
RXTX Warning: Removing stale lock file. /var/lock/LK.048.033.024
/users/rjth/desktop/2013
.DS_Store
3987089803_a66295422f_o 2.bmp
3987089803_a66295422f_o 3.bmp
3987089803_a66295422f_o 4.bmp
3987089803_a66295422f_o 5.bmp
3987089803_a66295422f_o 6.bmp
3987089803_a66295422f_o 7.bmp
3987089803_a66295422f_o.bmp
Exception in thread "Animation Thread" java.lang.ArrayIndexOutOfBoundsException: 8
at arduino_led_control3.draw(arduino_led_control3.java:50)
at processing.core.PApplet.handleDraw(PApplet.java:1631)
at processing.core.PApplet.run(PApplet.java:1530)
at java.lang.Thread.run(Thread.java:680)

any idea how to solve this problem? thanks

PhiLho

Re: How to open files from a directory, randomly?

5 months ago

loadImage(list[list.length]);
will fail, because list[] goes from 0 to list.length - 1.
Moreover, you want a random image.
So, try:
loadImage(list[int(random(list.length))]);
I suppose that's the intent to ramin which just forgot some elements...
Note: the for loop and its println() are just to verify list() works, they are not necessary for your sketch.

therjth

Re: How to open files from a directory, randomly?

5 months ago

thank you :)

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