/*  Part of XPCE --- The SWI-Prolog GUI toolkit

    Author:        Jan Wielemaker and Anjo Anjewierden
    E-mail:        jan@swi.psy.uva.nl
    WWW:           http://www.swi.psy.uva.nl/projects/xpce/
    Copyright (c)  1999-2011, University of Amsterdam
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in
       the documentation and/or other materials provided with the
       distribution.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.
*/

#include "boxes.h"

static status computeLBox(LBox lb);

static status
initialiseLBox(LBox lb, Int w)
{ if ( isDefault(w) )
    w = getClassVariableValueObject(lb, NAME_width);

  obtainClassVariablesObject(lb);
  initialiseDevice((Device)lb);

  assign(lb->area, w, w);

  succeed;
}

		 /*******************************
		 *	      COMPUTE		*
		 *******************************/

static status
PlaceLBox(LBox lp, Graphical gr, Int x, Int y, Int w)
{ DEBUG(NAME_lbox,
	Cprintf("Placing %s on %s at %d,%d (width = %s)\n",
		pp(gr), pp(lp), valInt(x), valInt(y), pp(w)));

  ComputeGraphical(gr);
  if ( gr->area->x != x || gr->area->y != y ||
       (notDefault(w) && gr->area->w != w) )
    setGraphical(gr, x, y, w, DEFAULT);

  succeed;
}


static Graphical
getLabelItem(Graphical item)
{ Chain ch;

  if ( (ch = getAllHypersObject(item, OFF)) )
  { Cell cell;

    for_cell(cell, ch)
    { Hyper h = cell->value;

      if ( h->to == item && h->backward_name == NAME_label &&
	   instanceOfObject(h->from, ClassGraphical) )
	answer(h->from);		/* I'm an item */
      if ( h->from == item && h->forward_name == NAME_item )
	fail;				/* I'm a label */
    }
  }

  return NIL;				/* I have no label */
}


static status
computeLBox(LBox lb)
{ if ( notNil(lb->request_compute) )
  { Cell cell;
    int lm   = valInt(lb->left_margin);
    int rm   = valInt(lb->right_margin);
    int isep = valInt(lb->item_sep);
    int lsep = valInt(lb->label_sep);
    int cy   = valInt(lb->top_sep);
    int iw   = valInt(lb->area->w) - lm - rm;

    if ( iw < 0 )
      goto out;

    for_cell(cell, lb->graphicals)
    { Graphical label;
      Graphical item = cell->value;

      if ( (label = getLabelItem(item)) ) /* i.e. I am an item */
      { int lh;

	if ( notNil(label) )
	{ ComputeGraphical(label);

	  PlaceLBox(lb, label,
		    toInt(lm - lsep - valInt(label->area->w)),
		    toInt(cy),
		    lb->label_width);
	  lh = valInt(label->area->h);
	} else
	  lh = 0;

	PlaceLBox(lb, cell->value, toInt(lm), toInt(cy), toInt(iw));

	cy += max(lh, valInt(item->area->h));
	cy += isep;
      }
    }

    cy -= isep;				/* correct for last */
    cy += valInt(lb->top_sep);

    if ( valInt(lb->area->h) != cy )
    { CHANGING_GRAPHICAL(lb,
      { assign(lb->area, h, toInt(cy));
      });
    }

  out:
    assign(lb, request_compute, NIL);
  }

  succeed;
}


static Int
getItemWidthLBox(LBox lb)
{ int iw = valInt(lb->area->w) -
           valInt(lb->left_margin) -
	   valInt(lb->right_margin);

  if ( iw < 0 )
    iw = 0;

  answer(toInt(iw));
}

		 /*******************************
		 *	      GEOMETRY		*
		 *******************************/

static status
geometryLBox(LBox lb, Int x, Int y, Int w, Int h)
{ if ( notDefault(w) && w != lb->area->w )
  { CHANGING_GRAPHICAL(lb,
		       assign(lb->area, w, w);
		       assign(lb, request_compute, DEFAULT);
		       computeLBox(lb));
  }

  return geometryDevice((Device)lb, x, y, DEFAULT, DEFAULT);
}

		 /*******************************
		 *	       ITEM		*
		 *******************************/

static status
appendLBox(LBox lb, Graphical label, Graphical item)
{ if ( isDefault(label) )
    label = get(lb, NAME_newLabel, EAV);
  if ( isDefault(item) )
    item  = get(lb, NAME_newItem, EAV);

  if ( item && (item = checkType(item, TypeGraphical, lb)) )
  { if ( label && (label = checkType(label, TypeGraphical, lb)) )
    { send(lb, NAME_display, label, EAV);
      send(lb, NAME_display, item,  EAV);
      newObject(ClassChainHyper, label, item, NAME_item, NAME_label, EAV);
    } else
      send(lb, NAME_display, item,  EAV);

    succeed;
  }

  fail;					/* error? */
}


static Graphical
getNewLabelLBox(LBox lb)
{ fail;
}


static Graphical
getNewItemLBox(LBox lb)
{ answer(answerObject(ClassParBox, getItemWidthLBox(lb), EAV));
}


		 /*******************************
		 *	 CLASS DECLARATION	*
		 *******************************/

/* Type declaractions */

static char *T_append[] =
	{ "label=[graphical]", "item=[graphical]" };
static char *T_geometry[] =
        { "x=[int]", "y=[int]", "width=[int]", "height=[int]" };

/* Instance Variables */

static vardecl var_lbox[] =
{ IV(NAME_leftMargin, "0..", IV_GET,
     NAME_layout, "Distance left of paragraphs"),
  IV(NAME_rightMargin, "0..", IV_GET,
     NAME_layout, "Distance right of paragraphs"),
  IV(NAME_topSep, "0..", IV_GET,
     NAME_layout, "Vertical skip around environment"),
  IV(NAME_itemSep, "0..", IV_GET,
     NAME_layout, "Vertical skip between items"),
  IV(NAME_labelSep, "0..", IV_GET,
     NAME_layout, "Horizontal skip from label to paragraph"),
  IV(NAME_labelWidth, "[0..]", IV_GET,
     NAME_layout, "Width of label-box")
};

/* Send Methods */

static senddecl send_lbox[] =
{ SM(NAME_initialise, 1, "width=[0..]", initialiseLBox,
     DEFAULT, "Create lbox of specified width"),
  SM(NAME_compute, 0, NULL, computeLBox,
     DEFAULT, "Recompute layout"),
  SM(NAME_geometry, 4, T_geometry, geometryLBox,
     DEFAULT, "Change lbox width"),
  SM(NAME_append,  2, T_append, appendLBox,
     DEFAULT, "Append label and item")
};

/* Get Methods */

static getdecl get_lbox[] =
{ GM(NAME_newLabel, 0, "graphical*", NULL, getNewLabelLBox,
     NAME_organisation, "Create label for new item"),
  GM(NAME_newItem,  0, "graphical*", NULL, getNewItemLBox,
     NAME_organisation, "Create new item body"),
  GM(NAME_itemWidth,  0, "int", NULL, getItemWidthLBox,
     NAME_layout, "Width of an item")
};

/* Resources */

static classvardecl rc_lbox[] =
{
  RC(NAME_leftMargin,	NULL,  "40",	   NULL),
  RC(NAME_rightMargin,	NULL,  "20",	   NULL),
  RC(NAME_topSep,	NULL,  "5",	   NULL),
  RC(NAME_itemSep,	NULL,  "10",	   NULL),
  RC(NAME_labelSep,	NULL,  "5",	   NULL),
  RC(NAME_labelWidth,	NULL,  "@default", NULL),
  RC(NAME_width,	"0..", "0",	   "Default initial width")
};

/* Class Declaration */

ClassDecl(lbox_decls,
          var_lbox, send_lbox, get_lbox, rc_lbox,
          0, NULL);


status
makeClassLBox(Class class)
{ return declareClass(class, &lbox_decls);
}
