path-chemistry.cpp

#define __SP_PATH_CHEMISTRY_C__

/*
 * Here are handlers for modifying selections, specific to paths
 *
 * Authors:
 *   Lauris Kaplinski <lauris@kaplinski.com>
 *
 * Copyright (C) 1999-2002 Authors
 * Copyright (C) 2001-2002 Ximian, Inc.
 *
 * Released under GNU GPL, read the file 'COPYING' for more information
 */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <string.h>
#include "libnr/nr-macros.h"
#include "xml/repr.h"
#include "svg/svg.h"
#include "display/curve.h"
#include <glibmm/i18n.h>
#include "sp-object.h"
#include "sp-path.h"
#include "sp-text.h"
#include "style.h"
#include "inkscape.h"
#include "document.h"
#include "selection.h"
#include "desktop-handles.h"
#include "path-chemistry.h"
#include "desktop.h"

/* Helper functions for sp_selected_path_to_curves */
static void sp_selected_path_to_curves0 (gboolean do_document_done, guint32 text_grouping_policy);
static SPRepr * sp_selected_item_to_curved_repr(SPItem * item, guint32 text_grouping_policy);
enum {                        
  /* Not used yet. This is the placeholder of Lauris's idea. */
      SP_TOCURVE_INTERACTIVE       = 1 << 0,
      SP_TOCURVE_GROUPING_BY_WORD  = 1 << 1,
      SP_TOCURVE_GROUPING_BY_LINE  = 1 << 2,
      SP_TOCURVE_GROUPING_BY_WHOLE = 1 << 3
};

void
sp_selected_path_combine (void)
{
      SPDesktop *desktop = SP_ACTIVE_DESKTOP;
      if (!SP_IS_DESKTOP(desktop))
        return;
      
      SPSelection *selection = SP_DT_SELECTION (desktop);
      GSList *items = (GSList *) selection->itemList();

      if (g_slist_length (items) < 2) {
          desktop->messageStack()->flash(Inkscape::WARNING_MESSAGE, _("Select <b>at least two objects</b> to combine."));
            return;
      }

      for (GSList *i = items; i != NULL; i = i->next) {
            SPItem *item = (SPItem *) i->data;
            if (!SP_IS_SHAPE (item) && !SP_IS_TEXT(item)) {
                desktop->messageStack()->flash(Inkscape::WARNING_MESSAGE, _("At least one of the objects is <b>not a path</b>, cannot combine."));
                return;
            }
      }

      SPRepr *parent = SP_OBJECT_REPR ((SPItem *) items->data)->parent();
      for (GSList *i = items; i != NULL; i = i->next) {
            if ( SP_OBJECT_REPR ((SPItem *) i->data)->parent() != parent ) {
                desktop->messageStack()->flash(Inkscape::ERROR_MESSAGE, _("You cannot combine objects from <b>different groups</b> or <b>layers</b>."));
                return;
            }
      }

      sp_selected_path_to_curves0 (FALSE, 0);

      items = (GSList *) selection->itemList();

      items = g_slist_copy (items);

      items = g_slist_sort (items, (GCompareFunc) sp_item_repr_compare_position);

      // remember the position of the topmost object
      gint topmost = sp_repr_position (SP_OBJECT_REPR ((SPItem *) g_slist_last(items)->data));

      // remember the id of the bottomost object
      const char *id = sp_repr_attr (SP_OBJECT_REPR ((SPItem *) items->data), "id");

      // FIXME: merge styles of combined objects instead of using the first one's style
      gchar *style = g_strdup (sp_repr_attr (SP_OBJECT_REPR ((SPItem *) items->data), "style"));

      GString *dstring = g_string_new("");
      for (GSList *i = items; i != NULL; i = i->next) {

            SPPath *path = (SPPath *) i->data;
            SPCurve *c = sp_shape_get_curve (SP_SHAPE (path));
            
            NArtBpath *abp = nr_artpath_affine(c->bpath, SP_ITEM(path)->transform);
            sp_curve_unref (c);
            gchar *str = sp_svg_write_path (abp);
            nr_free (abp);

            dstring = g_string_append(dstring, str);
            g_free (str);

            // if this is the bottommost object,
            if (!strcmp (sp_repr_attr (SP_OBJECT_REPR (path), "id"), id)) {
                  // delete it so that its clones don't get alerted; this object will be restored shortly, with the same id
                  SP_OBJECT (path)->deleteObject(false);
            } else {
                  // delete the object for real, so that its clones can take appropriate action
                  SP_OBJECT (path)->deleteObject();
            }

            topmost --;
      }

      g_slist_free (items);

      SPRepr *repr = sp_repr_new ("svg:path");

      // restore id
      sp_repr_set_attr (repr, "id", id);

      sp_repr_set_attr (repr, "style", style);
      g_free (style);

      sp_repr_set_attr (repr, "d", dstring->str);
      g_string_free (dstring, TRUE);

      // add the new group to the group members' common parent
      sp_repr_append_child (parent, repr);

      // move to the position of the topmost, reduced by the number of deleted items
      sp_repr_set_position_absolute (repr, topmost > 0 ? topmost + 1 : 0);

      sp_document_done (SP_DT_DOCUMENT (desktop));

      selection->setRepr(repr);

      sp_repr_unref (repr);
}

void
sp_selected_path_break_apart (void)
{
      SPDesktop *desktop = SP_ACTIVE_DESKTOP;
      if (!SP_IS_DESKTOP(desktop))
        return;
      
      SPSelection *selection = SP_DT_SELECTION (desktop);

      if (selection->isEmpty()) {
          desktop->messageStack()->flash(Inkscape::WARNING_MESSAGE, _("Select <b>path(s)</b> to break apart."));
            return;
      }

      bool did = false;

      for (GSList *items = g_slist_copy((GSList *) selection->itemList());
                   items != NULL;
                   items = items->next) {

            SPItem *item = (SPItem *) items->data;

            if (!SP_IS_PATH (item)) 
                  continue;

            SPPath *path = SP_PATH (item);

            SPCurve *curve = sp_shape_get_curve (SP_SHAPE (path));
            if (curve == NULL) 
                  continue;

            did = true;

            SPRepr *parent = SP_OBJECT_REPR (item)->parent();
            gint pos = sp_repr_position (SP_OBJECT_REPR (item));
            const char *id = sp_repr_attr (SP_OBJECT_REPR (item), "id");

            gchar *style = g_strdup (sp_repr_attr (SP_OBJECT (item)->repr, "style"));

            NArtBpath *abp = nr_artpath_affine (curve->bpath, sp_item_i2root_affine (SP_ITEM (path)));

            sp_curve_unref (curve);

            // it's going to resurrect as one of the pieces, so we delete without advertisement
            SP_OBJECT (item)->deleteObject(false);

            curve = sp_curve_new_from_bpath (abp);
            g_assert (curve != NULL);

            GSList *list = sp_curve_split (curve);

            sp_curve_unref (curve);

            for (GSList *l = g_slist_reverse(list); l != NULL; l = l->next) {
                  curve = (SPCurve *) l->data;

                  SPRepr *repr = sp_repr_new ("svg:path");
                  sp_repr_set_attr (repr, "style", style);

                  gchar *str = sp_svg_write_path (curve->bpath);
                  sp_repr_set_attr (repr, "d", str);
                  g_free (str);

                  // add the new repr to the parent
                  sp_repr_append_child (parent, repr);

                  // move to the saved position 
                  sp_repr_set_position_absolute (repr, pos > 0 ? pos : 0);

                  // if it's the first one, restore id
                  if (l == list)
                        sp_repr_set_attr (repr, "id", id);

                  selection->addRepr(repr);

                  sp_repr_unref (repr);
            }

            g_slist_free (list);
            g_free (style);

      }

      if (did) {
            sp_document_done (SP_DT_DOCUMENT (desktop));
      } else {
          desktop->messageStack()->flash(Inkscape::ERROR_MESSAGE, _("<b>No path(s)</b> to break apart in the selection."));
          return;
      } 
}

/* This function is an entry point from GUI */
void
sp_selected_path_to_curves (void)
{
      sp_selected_path_to_curves0(TRUE, SP_TOCURVE_INTERACTIVE);
}

static void
sp_selected_path_to_curves0 (gboolean interactive, guint32 text_grouping_policy)
{
      SPDesktop *desktop = SP_ACTIVE_DESKTOP;
      if (!SP_IS_DESKTOP(desktop))
        return;

      SPSelection *selection = SP_DT_SELECTION (desktop);

      if (selection->isEmpty()) {
            if (interactive)
                desktop->messageStack()->flash(Inkscape::WARNING_MESSAGE, _("Select <b>object(s)</b> to convert to path."));
            return;
      }

      bool did = false;

      for (GSList *items = g_slist_copy((GSList *) selection->itemList());
                   items != NULL;
                   items = items->next) {

            SPItem *item = SP_ITEM (items->data);

            SPRepr *repr = sp_selected_item_to_curved_repr (item, 0);
            if (!repr)
                  continue;
            
            did = true;

            // remember the position of the item
            gint pos = sp_repr_position (SP_OBJECT_REPR (item));
            // remember parent
            SPRepr *parent = SP_OBJECT_REPR (item)->parent();
            // remember id
            const char *id = sp_repr_attr (SP_OBJECT_REPR (item), "id");

            selection->removeItem (item);

            // it's going to resurrect, so we delete without advertisement
            SP_OBJECT (item)->deleteObject(false);

            // restore id
            sp_repr_set_attr (repr, "id", id);
            // add the new repr to the parent
            sp_repr_append_child (parent, repr);
            // move to the saved position 
            sp_repr_set_position_absolute (repr, pos > 0 ? pos : 0);

            selection->addRepr(repr);
            sp_repr_unref(repr);
      }

      if (interactive) {
            if (did) {
                  sp_document_done (SP_DT_DOCUMENT (desktop));
            } else {
                desktop->messageStack()->flash(Inkscape::ERROR_MESSAGE, _("<b>No objects</b> to convert to path in the selection."));
                return;
            }
      }
}

static SPRepr *
sp_selected_item_to_curved_repr(SPItem * item, guint32 text_grouping_policy)
{
      if (!item)
        return NULL;

      SPCurve *curve = NULL;
      if (SP_IS_SHAPE (item)) {
            curve = sp_shape_get_curve (SP_SHAPE (item));
      } else if (SP_IS_TEXT (item)) {
            curve = sp_text_normalized_bpath (SP_TEXT (item));
      }
      
      if (!curve)
        return NULL;
      
      SPRepr *repr = sp_repr_new ("svg:path");
      /* Transformation */
      sp_repr_set_attr (repr, "transform", 
                    sp_repr_attr (SP_OBJECT_REPR (item), "transform"));
      /* Style */
      gchar *style_str = sp_style_write_difference (SP_OBJECT_STYLE (item), 
                                     SP_OBJECT_STYLE (SP_OBJECT_PARENT (item)));
      sp_repr_set_attr (repr, "style", style_str);
      g_free (style_str);

      /* Definition */
      gchar *def_str = sp_svg_write_path (curve->bpath);
      sp_repr_set_attr (repr, "d", def_str);
      g_free (def_str);
      sp_curve_unref (curve);
      return repr;
}

void
sp_path_cleanup (SPPath *path)
{
      if (strcmp (sp_repr_name (SP_OBJECT_REPR (path)), "svg:path"))
        return;

      SPStyle *style = SP_OBJECT_STYLE (path);
      if (style->fill.type == SP_PAINT_TYPE_NONE)
        return;

      SPCurve *curve = sp_shape_get_curve (SP_SHAPE (path));
      if (!curve)
        return;
      
      GSList *c = sp_curve_split (curve);
      sp_curve_unref (curve);

      gboolean dropped = FALSE;
      GSList *curves = NULL;
      while (c) {
            curve = (SPCurve *) c->data;
            if (curve->closed) {
                  curves = g_slist_prepend (curves, curve);
            } else {
                  dropped = TRUE;
                  sp_curve_unref (curve);
            }
            c = g_slist_remove (c, c->data);
      }
      curves = g_slist_reverse (curves);

      curve = sp_curve_concat (curves);

      while (curves) {
            sp_curve_unref ((SPCurve *) curves->data);
            curves = g_slist_remove (curves, curves->data);
      }

      if (sp_curve_is_empty (curve)) {
            SP_OBJECT (path)->deleteObject();
      } else if (dropped) {
            gchar *svgpath;
            svgpath = sp_svg_write_path (curve->bpath);
            sp_repr_set_attr (SP_OBJECT_REPR (path), "d", svgpath);
            g_free (svgpath);
      }

      sp_curve_unref (curve);
}

void
sp_selected_path_reverse ()
{
      SPDesktop *desktop = SP_ACTIVE_DESKTOP;
      if (!SP_IS_DESKTOP(desktop))
        return;
      
      SPSelection *selection = SP_DT_SELECTION (desktop);
      GSList *items = (GSList *) selection->itemList();

      if (g_slist_length (items) == 0) {
          desktop->messageStack()->flash(Inkscape::WARNING_MESSAGE, _("Select <b>path(s)</b> to reverse."));
          return;
      }


      bool did = false;
      for (GSList *i = items; i != NULL; i = i->next) {

            if (!SP_IS_SHAPE (items->data))
                  continue;

            did = true;
            SPShape *shape = SP_SHAPE (items->data);

            SPCurve *rcurve = sp_curve_reverse (shape->curve);

            char *str = sp_svg_write_path (rcurve->bpath);
            sp_repr_set_attr (SP_OBJECT_REPR (shape), "d", str);

            sp_curve_unref (rcurve);
      }

      if (did) {
            sp_document_done (SP_DT_DOCUMENT (desktop));
      } else {
          desktop->messageStack()->flash(Inkscape::ERROR_MESSAGE, _("<b>No paths</b> to reverse in the selection."));
      } 
}