root/branches/clutter-experiments/page.hh

// TODO: move implementation in .cc file
// TODO: refine api, it's somewhat ugly right now
// TODO: should we render in a thread?
#ifndef __PDFCUBE__PAGE_HH__
#define __PDFCUBE__PAGE_HH__

#include <glib.h>
#include <poppler.h>
#include <gdk-pixbuf/gdk-pixbuf.h>

namespace pdfcube 
{

  /**
   * @brief The pdfcube::page class is the link between a PopplerPage
   * and ClutterActor GObjects.
   *
   * This class is used to render low and hi res version of a
   * PopplerPage as GdkPixbufs
   *
   * Usually, on start, all the pages will be rendered in a low res
   * version, while higher res versions will be rendered on demand by
   * the animations. 
   *
   * While displaying one page the following page is rendered in high
   * resolution. No forward animation is possible until the rendering
   * finishes.
   *
   */
  class page 
  {
  public:
    /**
     * @brief Ctor. 
     *
     * This is used internally by pdfcube::document. (FIXME: make
     * protected and friend of document?)
     * 
     * @param poppler_page a PopplerPage*
     *
     */
    page(PopplerPage* poppler_page) 
      : poppler_page_m(poppler_page),
        low_res_m(NULL),
        hi_res_m(NULL)
    { }
    
    double
    aspect_ratio()
    {
      double w, h;
      poppler_page_get_size(poppler_page_m, &w, &h);
      return w/h;
    }

    std::pair<double, double>
    size()
    {
      double w, h;
      poppler_page_get_size(poppler_page_m, &w, &h);
      return std::make_pair(w,h);
    }
    
    enum rendering_mode { LOW_RES, HI_RES };
    
    /**
     * @brief Renders the PopplerPage on the desired pixbuf.
     */
    void
    render(rendering_mode mode)
    { 
      switch(mode)
        {
        case LOW_RES:
          {
            int w,h;
            // we assume 4/3 aspect monitor can do better
            double box_w = 320;
            double box_h = 240;
            double aspect = aspect_ratio();
            // Check if our slot ratio is less or more than owr own
            if(box_h > box_w/aspect)
              {
                w = box_w;
                h = w/aspect;
              }
            else 
              {
                h = box_h;
                w = h*aspect;
              }

            if(!low_res_m)
              low_res_m = gdk_pixbuf_new(GDK_COLORSPACE_RGB, TRUE, 8, w, h);
            poppler_page_render_to_pixbuf(poppler_page_m, 
                                          0,
                                          0, 
                                          w, 
                                          h, 
                                          ((double)h)/size().second, 
                                          0, 
                                          low_res_m);
            break;
          }
        case HI_RES:
          {
            int w, h;
            // FIXME: we assume 4/3 aspect monitor. 
            double box_w = 1600;
            double box_h = 1200;
            double aspect = aspect_ratio();
            // Check if our slot ratio is less or more than owr own
            if(box_h > box_w/aspect)
              {
                w = box_w;
                h = w/aspect;
              }
            else 
              {
                h = box_h;
                w = h*aspect;
              }
            if(!hi_res_m)
              hi_res_m = gdk_pixbuf_new(GDK_COLORSPACE_RGB, TRUE, 8, w, h);
            poppler_page_render_to_pixbuf(poppler_page_m, 
                                          0,
                                          0, 
                                          w, 
                                          h, 
                                          ((double)h)/size().second, 
                                          0, 
                                          hi_res_m);
            break;
          }
        }
    };

    /**
     * @brief Frees an unneeded actor.
     */
    void
    free(rendering_mode mode)
    { 
      switch(mode)
        {
        case LOW_RES:
          g_object_unref(low_res_m);
          low_res_m = NULL;
          break;
        case HI_RES:
          g_object_unref(hi_res_m);
          hi_res_m = NULL;
          break;
        }
    };

    /**
     * @brief Tells if the desired version is available.
     */
    bool
    has(rendering_mode mode)
    { 
      switch(mode)
        {
        case LOW_RES:
          return low_res_m != NULL;
        case HI_RES:
          return hi_res_m != NULL;
        }
      return false;
    };

    /**
     * @brief Returns the desired actor (on NULL if not present).
     */
    GdkPixbuf* 
    pixbuf(rendering_mode mode)
    {
      switch(mode)
        {
        case LOW_RES:
          return low_res_m;
        case HI_RES:
          return hi_res_m;
        }
      return NULL;
    }

    PopplerPageTransitionType transition_type()
    {
      PopplerPageTransition* ppt = poppler_page_get_transition(poppler_page_m);
      if(ppt) return ppt->type;
      else return POPPLER_PAGE_TRANSITION_REPLACE;
    }

  protected:

    /*
     * GList PopplerLinkMapping enumerating function
     */
    void link_function(gpointer data, gpointer user_data)
    {
      PopplerLinkMapping* link = (PopplerLinkMapping*)data;
      g_print("Link area (%f,%f)x(%f,%f)\n", 
              link->area.x1,  
              link->area.y1, 
              link->area.x2, 
              link->area.y2); 
    }

    PopplerPage* poppler_page_m;
    GdkPixbuf* low_res_m;
    GdkPixbuf* hi_res_m;
  };

}

#endif