/******************************************************
 *
 * canvasdelete - implementation file
 *
 * copyleft (c) IOhannes m zmölnig
 *
 *   2007:forum::für::umläute:2007
 *
 *   institute of electronic music and acoustics (iem)
 *
 ******************************************************
 *
 * license: GNU General Public License v.2
 *
 ******************************************************/


/* 
 * this object deletes itself (or the specified parent canvas) when banged
 */

#include "m_pd.h"

#include "g_canvas.h"

/* ------------------------- canvasdelete ---------------------------- */

static t_class *canvasdelete_class;

typedef struct _canvasdelete
{
  t_object  x_obj;

  t_glist*x_glist;
  t_gobj *x_gobj;

  t_clock  *x_clock;
} t_canvasdelete;
static void canvasdelete_doit(t_canvasdelete *x)
{
  int dspstate= canvas_suspend_dsp();
  clock_free(x->x_clock);
  x->x_clock=NULL;

  glist_delete(x->x_glist, x->x_gobj);

  canvas_resume_dsp(dspstate);
}

static void canvasdelete_bang(t_canvasdelete *x)
{
  int x1=0, y1=0, width=0, height=0;
  t_atom alist[2];

  if(x->x_clock) {
    pd_error(x, "deletion already scheduled");
    return;
  }

  if(NULL==x->x_glist || NULL==x->x_gobj)return;

  x->x_clock=clock_new(x, (t_method)canvasdelete_doit);
  clock_delay(x->x_clock, 0);
}

static void *canvasdelete_new(t_floatarg f)
{
  t_canvasdelete *x = (t_canvasdelete *)pd_new(canvasdelete_class);
  t_glist *glist=(t_glist *)canvas_getcurrent();
  t_canvas *canvas=(t_canvas*)glist_getcanvas(glist);
  t_gobj*obj=(t_gobj*)x;
  int depth=(int)f;
  
  if(depth<0)depth=0;

  while(depth && canvas) {
    obj=(t_gobj*)canvas;
    canvas=canvas->gl_owner;
    depth--;
  }

  x->x_glist = canvas;
  x->x_gobj=obj;
  
  x->x_clock=NULL;

  return (x);
}

static void canvasdelete_free(t_canvasdelete*x)
{

}

static void canvasdelete_canvasmethods(void);

void canvasdelete_setup(void)
{
  canvasdelete_class = class_new(gensym("canvasdelete"), 
                                 (t_newmethod)canvasdelete_new, (t_method)canvasdelete_free, 
                                 sizeof(t_canvasdelete), 0,
                                 A_DEFFLOAT, 0);
  class_addbang(canvasdelete_class, (t_method)canvasdelete_bang);

  canvasdelete_canvasmethods();
}


/* 'delete' message for the canvas */
static int canvas_delete_docb(t_glist*glist, int index) {
  /* this will crash Pd if the object to be deleted is on the stack
   * workarounds: 
   *   - use a clock (see above)
   *   - finally fix this in Pd
   */
  t_gobj*obj=NULL;
  int i=index;
  if(NULL==glist) {
    return -1;
  }
  if(i<0) {
    return -1;
  }

  obj=glist->gl_list;

  while(i-- && obj) {
    obj=obj->g_next;
  }

  if(obj) {
    glist_delete(glist, obj);
  }
  else {
    return -1;
  }

  return index;
}

static void canvas_delete_cb(t_canvas*x, t_symbol*s, int argc, t_atom*argv)
{
  int dspstate= canvas_suspend_dsp();
  if(argc) {
    while(argc--){
      canvas_delete_docb(x, atom_getint(argv++));
    }
  }
  canvas_resume_dsp(dspstate);
}


static void canvasdelete_canvasmethods(void) {
  if(NULL==canvas_class)return;
  if(NULL==zgetfn(&canvas_class, gensym("delete"))) {
    verbose(0, "adding 'delete' method to canvas");
    class_addmethod(canvas_class, (t_method)canvas_delete_cb, gensym("delete"), A_GIMME, 0);
  }

}