// src/schedulables_widget.cc - Copyright 2005, 2006, University
//               of Padova, dept. of Pure and Applied
//               Mathematics
//
// This file is part of SGPEMv2.
//
// This is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// SGPEMv2 is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with SGPEMv2; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA

#include "cairo_elements.hh"
#include "schedulables_widget.hh"

#include <cmath>

using namespace sgpem;


SchedulablesWidget::SchedulablesWidget()
  : Gtk::DrawingArea(), _ctx(NULL)
{
  // Add other events we want to manage (as mouse clicks)
  // when needed
  add_events(Gdk::EXPOSURE_MASK);
}
 

SchedulablesWidget::~SchedulablesWidget()
{
  if(_ctx != NULL)
    cairo_destroy(_ctx);
}


void 
SchedulablesWidget::update(const History& history)
{
  // FIXME : write me using double buffering
  // GdkPixmap* buffer = gdk_pixmap_new(...);
  // _ctx = gdk_cairo_create(buffer);

  // do the drawing...


  // NOTE: just to try
  CairoElements ce(_ctx);
  Color red = { 1, 0, 0 };
  Point center = { 25, 25 };

  ce.draw_3dsphere(center, 25, red);

  // manually force an expose_event?  
}

 
void 
SchedulablesWidget::on_size_request(Gtk::Requisition* requisition)
{
  // FIXME: take correct measures, consider also using a viewport(?)
  *requisition = Gtk::Requisition();
  requisition->width = get_allocation().get_width();
  requisition->height = requisition->width;
}


bool 
SchedulablesWidget::on_expose_event(GdkEventExpose* event)
{
  // Use double buffering or we're CPU-dead
  Glib::RefPtr<Gdk::Window> window = get_window();
  GdkWindow* gdkWindow = window->gobj();
  GdkDrawable* gdkDrawable;
  gint xOffset, yOffset;
  gdk_window_get_internal_paint_info(gdkWindow, &gdkDrawable, &xOffset, &yOffset);

  // Copy new ctx from old one (the buffer); from distant memories,
  // we should use something like create_similar to instantiate a 
  // compatible surface and then copy the buffer to fg
  // So the following two lines WILL HAVE TO CHANGE.
  if(_ctx == NULL)
    _ctx = gdk_cairo_create(gdkDrawable);

  cairo_t* cr = gdk_cairo_create(gdkDrawable); 
  
  const Gtk::Allocation& allocation = get_allocation();
  int width  = allocation.get_width();
  int height = allocation.get_height();
  
  // Clip to redraw only the smallest possible area
  if(event) 
    {
      cairo_rectangle(cr, event->area.x, event->area.y,
		      event->area.width, event->area.height);
      cairo_clip(cr);
    }

  // should be calculated dinamically:
  set_size_request(200,400);
  
  // Copy from buffer to video
  // if(_ctx != NULL)
  //   gdk_draw_drawable(buffer, GC??, gdkDrawable, ...clip-region...);

  // Height should be calculated dynamically?
  cairo_scale(cr, width, width);

  cairo_destroy(cr);
  return true; 
}
 

bool 
SchedulablesWidget::on_button_press_event(GdkEventButton* event)
{
  // Not here. Yet.
  return false;
}