<?php
 
class Graph_Core extends GtkDrawingArea {
  # prefix class attributes with "_" to avoid collisions
  # with GtkDrawingArea attributes.
  protected $_pixmap;
  protected $_gc;
  protected $_realized;
 
  function __construct() {
    parent::__construct();
 
    $this->connect('expose_event',
      array($this, 'expose_event'));
    $this->connect('configure_event',
      array($this, 'configure_event'));
    $this->connect('realize',
      array($this, 'realize'));
    $this->set_events(Gdk::EXPOSURE_MASK
      | Gdk::LEAVE_NOTIFY_MASK);
 
    $this->_pixmap = null;
    $this->_gc = null;
    $this->_realized = false;
  }
 
  function realize() {
    $this->_realized = true;
  }
 
  function realized() {
    return $this->_realized;
  }
 
  function configure_event($widget, $event) {
    $w = $this->width();
    $h = $this->height();
 
    # allocate a new pixmap of the requested size ($this->allocation)
    $this->_pixmap = new GdkPixmap($this->window, $w, $h, -1);
 
    # clear pixmap (white color)
    $this->_pixmap->draw_rectangle($this->style->white_gc, true,
      0, 0, $w, $h);
 
    return true;
  }
 
  function expose_event($widget, $event) {
    $this->window->draw_drawable($this->style->fg_gc[$this->state],
      $this->pixmap(),
      $event->area->x, $event->area->y,
      $event->area->x, $event->area->y,
      $event->area->width, $event->area->height
    );
    return false;
  }
 
  function set_color($color) {
    $col = $this->colormap()->alloc_color($color);
    if ($col === false)
      return $this->foreground('black');
    return $this->gc()->set_foreground($col);
  }
 
  function colormap() {
    return $this->gc()->get_colormap();
  }
 
  function pixmap() {
    if (!$this->realized()) {
      trigger_error("Widget not realized ; can't get pixmap");
      return null;
    }
    return $this->_pixmap;
  }
 
  function gc() {
    if (!$this->realized()) {
      trigger_error("Widget not realized ; can't get GC");
      return null;
    }
    if ($this->_gc == null)
      $this->_gc = new GdkGc($this->pixmap());
    return $this->_gc;
  }
 
  function width() {
    return $this->allocation->width;
  }
 
  function height() {
    return $this->allocation->height;
  }
 
  function w() {
    return $this->width();
  }
 
  function h() {
    return $this->height();
  }
}
 
 
class Grapher extends Graph_Core{
 
        function draw_line($x1, $y1, $x2, $y2){
                $this->pixmap()->draw_line($this->gc(), $x1, $y1, $x2, $y2);
                $w = $this->w();
                $h = $this->h();
                $this->queue_draw_area(0,0, $w, $h);
        }
 
        function refresh(){
                $w = $this->w();
                $h = $this->h();
                $this->queue_draw_area(0,0, $w, $h);
        }
 
        function configure_event($widget, $event) {
                parent::configure_event($widget, $event);
 
                $this->redraw($this);
        }
 
        function redraw(){
 
                if(!$this->realized())
                        return;
 
                $graph = $this;
                echo "graph draw - start\n";
                $this->set_color('blue');
                $lines = file_get_contents('world.xy');
                $lines = unserialize($lines);
 
                # look at optimisations here
                $pixmap = $this->pixmap();
                $gc = $this->gc();
                $w = $this->w() / 2;
                $h = $this->h();
 
                $scale = 8;
 
                $count = count($lines);
 
                echo "count = $count\n";
                foreach ($lines as $line) {
                        $pixmap->draw_line($gc, $w-($line[1]*$scale), $h-($line[0]*$scale), $w-($line[3]*$scale), $h-($line[2]*$scale));
                }
 
                $this->refresh();
 
                echo "graph draw - done\n";
        }
}
 
$grapher = new Grapher();  // note 1
$grapher->set_size_request(800, 600);
Gtk::timeout_add(100, array($grapher, 'redraw'));
 
$window = new GtkWindow();
$window->connect_simple('destroy', array('gtk', 'main_quit'));
$window->set_title('Graph demo');
$window->set_position(Gtk::WIN_POS_CENTER);
$window->set_border_width(8);
$window->add($grapher);
$window->show_all();
 
Gtk::main();

?>