import proxml.*;

/**
 * XML Pulses
 *
 * <p>Elie Zananiri<br>
 * CART 253, Winter 2008</p>
 */

// ----------------------------------------------------------------------
// GLOBAL CONSTANTS
// ----------------------------------------------------------------------
int MAX_PULSES = 500;

// ----------------------------------------------------------------------
// GLOBAL VARIABLES
// ----------------------------------------------------------------------
int numPulses = 0;
Pulse pulses[] = new Pulse[MAX_PULSES];
XMLInOut xmlIO;
XMLElement xmlPulses;

// ----------------------------------------------------------------------
// BUILT-IN FUNCTIONS
// ----------------------------------------------------------------------
void setup() {
  size(400, 400);
  smooth();
  noStroke();
  
  // load pulses from XML file, if it exists
  xmlIO = new XMLInOut(this);
  try {
    xmlIO.loadElement("pulses.xml"); 
  } catch (Exception e) {
    // the XML file could not be found, create a new XML root
    xmlEvent(new XMLElement("pulses"));
  }
}

/* called automatically whenever an XML file is loaded */
void xmlEvent(XMLElement element) {
  xmlPulses = element;
  initPulses();
}

void draw() {
  background(0);

  // draw all the pulses
  for (int i=0; i < numPulses; i++) {
    pulses[i].draw(); 
  }
}

void mousePressed() {
  addNewPulse(mouseX, mouseY); 
}

void mouseDragged() {
  addNewPulse(mouseX, mouseY); 
}

void mouseReleased() {
  savePulsesToDisk(); 
}

void keyPressed() {
  if (key == ' ') {
    // clear all
    clearPulses();
  } 
}

// ----------------------------------------------------------------------
// USER FUNCTIONS
// ----------------------------------------------------------------------
/* creates all pulses saved in the XML file */
void initPulses() {
  // create temporary XML nodes
  XMLElement pulse;
  XMLElement pos;
  XMLElement col;
  
  // parse through all pulse nodes to create Pulse objects
  for (int i=0; i < xmlPulses.countChildren(); i++) {
    pulse = xmlPulses.getChild(i);
    pos = pulse.getChild(0);
    col = pulse.getChild(1);
    
    addSavedPulse(pos.getIntAttribute("x"), pos.getIntAttribute("y"), col.getIntAttribute("rgb"));
  }
}

/* adds a new pulse to the display and XML lists */
void addNewPulse(int newX, int newY) {
  if (numPulses < MAX_PULSES) {
    pulses[numPulses] = new Pulse(newX, newY, color(random(255), random(255), random(255)));
    
    // create a new pulse XML node
    XMLElement newPulse = new XMLElement("pulse");
    // add it to the XML root
    xmlPulses.addChild(newPulse);
    // add a position XML node to the new pulse
    XMLElement pos = new XMLElement("position");
    pos.addAttribute("x", newX);
    pos.addAttribute("y", newY);
    newPulse.addChild(pos);
    // add a color XML node to the new pulse
    XMLElement col = new XMLElement("color");
    col.addAttribute("rgb", pulses[numPulses].c);
    newPulse.addChild(col);
    
    numPulses++;
  }
}

/* adds a saved pulse to the display list */
void addSavedPulse(int newX, int newY, color newCol) {
  if (numPulses < MAX_PULSES) {
    pulses[numPulses] = new Pulse(newX, newY, newCol);
    numPulses++;
  }
}

/* clears all pulses from the display and XML lists */
void clearPulses() {
  numPulses = 0;
  
  // create a new empty pulses XML list to overwrite the previous one
  xmlPulses = new XMLElement("pulses");
    
  // save the new empty list to disk
  savePulsesToDisk();
}

/* saves the pulses XML list to disk */
void savePulsesToDisk() {
  xmlIO.saveElement(xmlPulses, "pulses.xml");
}