src/gradient-drag.cpp

   1 #define __GRADIENT_DRAG_C__
   2
   3 /*
   4  * On-canvas gradient dragging
   5  *
   6  * Authors:
   7  *   bulia byak <buliabyak@users.sf.net>
   8  *   Johan Engelen <j.b.c.engelen@ewi.utwente.nl>
   9  *
  10  * Copyright (C) 2007 Johan Engelen
  11  * Copyright (C) 2005 Authors
  12  *
  13  * Released under GNU GPL, read the file 'COPYING' for more information
  14  */
  15
  16 #ifdef HAVE_CONFIG_H
  17 #include "config.h"
  18 #endif
  19
  20 #include <glibmm/i18n.h>
  21
  22 #include "desktop-handles.h"
  23 #include "selection.h"
  24 #include "desktop.h"
  25 #include "desktop-style.h"
  26 #include "document.h"
  27 #include "display/sp-ctrlline.h"
  28
  29 #include "xml/repr.h"
  30 #include "svg/css-ostringstream.h"
  31
  32 #include "svg/svg.h"
  33
  34 #include "prefs-utils.h"
  35 #include "sp-item.h"
  36 #include "style.h"
  37 #include "knot.h"
  38 #include "sp-linear-gradient.h"
  39 #include "sp-radial-gradient.h"
  40 #include "gradient-chemistry.h"
  41 #include "gradient-drag.h"
  42 #include "sp-stop.h"
  43
  44 #include "snap.h"
  45 #include "sp-namedview.h"
  46
  47
  48 #define GR_KNOT_COLOR_NORMAL 0xffffff00
  49 #define GR_KNOT_COLOR_SELECTED 0x0000ff00
  50
  51 #define GR_LINE_COLOR_FILL 0x0000ff7f
  52 #define GR_LINE_COLOR_STROKE 0x9999007f
  53
  54 // screen pixels between knots when they snap:
  55 #define SNAP_DIST 5
  56
  57 // absolute distance between gradient points for them to become a single dragger when the drag is created:
  58 #define MERGE_DIST 0.1
  59
  60 // knot shapes corresponding to GrPointType enum
  61 SPKnotShapeType gr_knot_shapes [] = {
  62         SP_KNOT_SHAPE_SQUARE, //POINT_LG_BEGIN
  63         SP_KNOT_SHAPE_CIRCLE,  //POINT_LG_END
  64         SP_KNOT_SHAPE_DIAMOND, //POINT_LG_MID
  65         SP_KNOT_SHAPE_SQUARE,  // POINT_RG_CENTER
  66         SP_KNOT_SHAPE_CIRCLE,  // POINT_RG_R1
  67         SP_KNOT_SHAPE_CIRCLE,  // POINT_RG_R2
  68         SP_KNOT_SHAPE_CROSS, // POINT_RG_FOCUS
  69         SP_KNOT_SHAPE_DIAMOND, //POINT_RG_MID1
  70         SP_KNOT_SHAPE_DIAMOND //POINT_RG_MID2
  71 };
  72
  73 const gchar *gr_knot_descr [] = {
  74     N_("Linear gradient <b>start</b>"), //POINT_LG_BEGIN
  75     N_("Linear gradient <b>end</b>"),
  76     N_("Linear gradient <b>midstop</b>"),
  77     N_("Radial gradient <b>center</b>"),
  78     N_("Radial gradient <b>radius</b>"),
  79     N_("Radial gradient <b>radius</b>"),
  80     N_("Radial gradient <b>focus</b>"), // POINT_RG_FOCUS
  81     N_("Linear gradient <b>midstop</b>"),
  82     N_("Linear gradient <b>midstop</b>")
  83 };
  84
  85 static void
  86 gr_drag_sel_changed(Inkscape::Selection *selection, gpointer data)
  87 {
  88         GrDrag *drag = (GrDrag *) data;
  89         drag->updateDraggers ();
  90         drag->updateLines ();
  91         drag->updateLevels ();
  92 }
  93
  94 static void
  95 gr_drag_sel_modified (Inkscape::Selection *selection, guint flags, gpointer data)
  96 {
  97     GrDrag *drag = (GrDrag *) data;
  98     if (drag->local_change) {
  99         drag->local_change = false;
 100     } else {
 101         drag->updateDraggers ();
 102     }
 103     drag->updateLines ();
 104     drag->updateLevels ();
 105 }
 106
 107 /**
 108 When a _query_style_signal is received, check that \a property requests fill/stroke/opacity (otherwise
 109 skip), and fill the \a style with the averaged color of all draggables of the selected dragger, if
 110 any.
 111 */
 112 int
 113 gr_drag_style_query (SPStyle *style, int property, gpointer data)
 114 {
 115     GrDrag *drag = (GrDrag *) data;
 116
 117     if (property != QUERY_STYLE_PROPERTY_FILL && property != QUERY_STYLE_PROPERTY_STROKE && property != QUERY_STYLE_PROPERTY_MASTEROPACITY) {
 118         return QUERY_STYLE_NOTHING;
 119     }
 120
 121     if (!drag->selected) {
 122         return QUERY_STYLE_NOTHING;
 123     } else {
 124         int ret = QUERY_STYLE_NOTHING;
 125
 126         float cf[4];
 127         cf[0] = cf[1] = cf[2] = cf[3] = 0;
 128
 129         int count = 0;
 130
 131         for (GSList const* i = ((GrDragger*)drag->selected->data)->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 132             GrDraggable *draggable = (GrDraggable *) i->data;
 133
 134             if (ret == QUERY_STYLE_NOTHING) {
 135                 ret = QUERY_STYLE_SINGLE;
 136             } else if (ret == QUERY_STYLE_SINGLE) {
 137                 ret = QUERY_STYLE_MULTIPLE_AVERAGED;
 138             }
 139
 140             guint32 c = sp_item_gradient_stop_query_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 141             cf[0] += SP_RGBA32_R_F (c);
 142             cf[1] += SP_RGBA32_G_F (c);
 143             cf[2] += SP_RGBA32_B_F (c);
 144             cf[3] += SP_RGBA32_A_F (c);
 145
 146             count ++;
 147         }
 148
 149         if (count) {
 150             cf[0] /= count;
 151             cf[1] /= count;
 152             cf[2] /= count;
 153             cf[3] /= count;
 154
 155             // set both fill and stroke with our stop-color and stop-opacity
 156             sp_color_set_rgb_float((SPColor *) &style->fill.value.color, cf[0], cf[1], cf[2]);
 157             style->fill.set = TRUE;
 158             style->fill.type = SP_PAINT_TYPE_COLOR;
 159             sp_color_set_rgb_float((SPColor *) &style->stroke.value.color, cf[0], cf[1], cf[2]);
 160             style->stroke.set = TRUE;
 161             style->stroke.type = SP_PAINT_TYPE_COLOR;
 162
 163             style->fill_opacity.value = SP_SCALE24_FROM_FLOAT (1.0);
 164             style->fill_opacity.set = TRUE;
 165             style->stroke_opacity.value = SP_SCALE24_FROM_FLOAT (1.0);
 166             style->stroke_opacity.set = TRUE;
 167
 168             style->opacity.value = SP_SCALE24_FROM_FLOAT (cf[3]);
 169             style->opacity.set = TRUE;
 170         }
 171
 172         return ret;
 173     }
 174 }
 175
 176 bool
 177 gr_drag_style_set (const SPCSSAttr *css, gpointer data)
 178 {
 179     GrDrag *drag = (GrDrag *) data;
 180
 181     if (!drag->selected)
 182         return false;
 183
 184     SPCSSAttr *stop = sp_repr_css_attr_new ();
 185
 186     // See if the css contains interesting properties, and if so, translate them into the format
 187     // acceptable for gradient stops
 188
 189     // any of color properties, in order of increasing priority:
 190     if (css->attribute("flood-color"))
 191         sp_repr_css_set_property (stop, "stop-color", css->attribute("flood-color"));
 192
 193     if (css->attribute("lighting-color"))
 194         sp_repr_css_set_property (stop, "stop-color", css->attribute("lighting-color"));
 195
 196     if (css->attribute("color"))
 197         sp_repr_css_set_property (stop, "stop-color", css->attribute("color"));
 198
 199     if (css->attribute("stroke") && strcmp(css->attribute("stroke"), "none"))
 200         sp_repr_css_set_property (stop, "stop-color", css->attribute("stroke"));
 201
 202     if (css->attribute("fill") && strcmp(css->attribute("fill"), "none"))
 203         sp_repr_css_set_property (stop, "stop-color", css->attribute("fill"));
 204
 205     if (css->attribute("stop-color"))
 206         sp_repr_css_set_property (stop, "stop-color", css->attribute("stop-color"));
 207
 208
 209     if (css->attribute("stop-opacity")) { // direct setting of stop-opacity has priority
 210         sp_repr_css_set_property (stop, "stop-opacity", css->attribute("stop-opacity"));
 211     } else {  // multiply all opacity properties:
 212         gdouble accumulated = 1.0;
 213         accumulated *= sp_svg_read_percentage(css->attribute("flood-opacity"), 1.0);
 214         accumulated *= sp_svg_read_percentage(css->attribute("opacity"), 1.0);
 215         accumulated *= sp_svg_read_percentage(css->attribute("stroke-opacity"), 1.0);
 216         accumulated *= sp_svg_read_percentage(css->attribute("fill-opacity"), 1.0);
 217
 218         Inkscape::CSSOStringStream os;
 219         os << accumulated;
 220         sp_repr_css_set_property (stop, "stop-opacity", os.str().c_str());
 221
 222         if ((css->attribute("fill") && !strcmp(css->attribute("fill"), "none")) ||
 223             (css->attribute("stroke") && !strcmp(css->attribute("stroke"), "none")))
 224             sp_repr_css_set_property (stop, "stop-opacity", "0"); // if set to none, don't change color, set opacity to 0
 225     }
 226
 227     if (!stop->attributeList()) { // nothing for us here, pass it on
 228         sp_repr_css_attr_unref(stop);
 229         return false;
 230     }
 231
 232     for (GList const* sel = drag->selected; sel != NULL; sel = sel->next) { // for all selected draggers
 233         GrDragger* dragger = (GrDragger*) sel->data;
 234         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 235                GrDraggable *draggable = (GrDraggable *) i->data;
 236
 237                drag->local_change = true;
 238                sp_item_gradient_stop_set_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke, stop);
 239         }
 240     }
 241
 242     //sp_repr_css_print(stop);
 243     sp_repr_css_attr_unref(stop);
 244     return true;
 245 }
 246
 247 GrDrag::GrDrag(SPDesktop *desktop) {
 248
 249     this->desktop = desktop;
 250
 251     this->selection = sp_desktop_selection(desktop);
 252
 253     this->draggers = NULL;
 254     this->lines = NULL;
 255     this->selected = NULL;
 256
 257     this->hor_levels.clear();
 258     this->vert_levels.clear();
 259
 260     this->local_change = false;
 261
 262     this->sel_changed_connection = this->selection->connectChanged(
 263         sigc::bind (
 264             sigc::ptr_fun(&gr_drag_sel_changed),
 265             (gpointer)this )
 266
 267         );
 268     this->sel_modified_connection = this->selection->connectModified(
 269         sigc::bind(
 270             sigc::ptr_fun(&gr_drag_sel_modified),
 271             (gpointer)this )
 272         );
 273
 274     this->style_set_connection = this->desktop->connectSetStyle(
 275         sigc::bind(
 276             sigc::ptr_fun(&gr_drag_style_set),
 277             (gpointer)this )
 278         );
 279
 280     this->style_query_connection = this->desktop->connectQueryStyle(
 281         sigc::bind(
 282             sigc::ptr_fun(&gr_drag_style_query),
 283             (gpointer)this )
 284         );
 285
 286     this->updateDraggers ();
 287     this->updateLines ();
 288     this->updateLevels ();
 289
 290     if (desktop->gr_item) {
 291         this->setSelected (getDraggerFor (desktop->gr_item, desktop->gr_point_type, desktop->gr_point_i, desktop->gr_fill_or_stroke));
 292     }
 293 }
 294
 295 GrDrag::~GrDrag()
 296 {
 297     this->sel_changed_connection.disconnect();
 298     this->sel_modified_connection.disconnect();
 299     this->style_set_connection.disconnect();
 300     this->style_query_connection.disconnect();
 301
 302     if (this->selected) {
 303         GrDraggable *draggable = (GrDraggable *)   ((GrDragger*)this->selected->data)->draggables->data;
 304         desktop->gr_item = draggable->item;
 305         desktop->gr_point_type = draggable->point_type;
 306         desktop->gr_point_i = draggable->point_i;
 307         desktop->gr_fill_or_stroke = draggable->fill_or_stroke;
 308     } else {
 309         desktop->gr_item = NULL;
 310         desktop->gr_point_type = 0;
 311         desktop->gr_point_i = 0;
 312         desktop->gr_fill_or_stroke = true;
 313     }
 314
 315     deselect_all();
 316     for (GList *l = this->draggers; l != NULL; l = l->next) {
 317         delete ((GrDragger *) l->data);
 318     }
 319     g_list_free (this->draggers);
 320     this->draggers = NULL;
 321     this->selected = NULL;
 322
 323     for (GSList *l = this->lines; l != NULL; l = l->next) {
 324         gtk_object_destroy( GTK_OBJECT (l->data));
 325     }
 326     g_slist_free (this->lines);
 327     this->lines = NULL;
 328 }
 329
 330 GrDraggable::GrDraggable (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke)
 331 {
 332     this->item = item;
 333     this->point_type = point_type;
 334     this->point_i = point_i;
 335     this->fill_or_stroke = fill_or_stroke;
 336
 337     g_object_ref (G_OBJECT (this->item));
 338 }
 339
 340 GrDraggable::~GrDraggable ()
 341 {
 342     g_object_unref (G_OBJECT (this->item));
 343 }
 344
 345 // FIXME: make global function in libnr or somewhere.
 346 static NR::Point *
 347 get_snap_vector (NR::Point p, NR::Point o, double snap, double initial)
 348 {
 349     double r = NR::L2 (p - o);
 350     if (r < 1e-3)
 351         return NULL;
 352     double angle = NR::atan2 (p - o);
 353     // snap angle to snaps increments, starting from initial:
 354     double a_snapped = initial + floor((angle - initial)/snap + 0.5) * snap;
 355     // calculate the new position and subtract p to get the vector:
 356     return new NR::Point (o + r * NR::Point(cos(a_snapped), sin(a_snapped)) - p);
 357 }
 358
 359 // FIXME: make global function in libnr or somewhere.
 360 static NR::Point
 361 snap_vector_midpoint (NR::Point p, NR::Point begin, NR::Point end, double snap)
 362 {
 363     double length = NR::L2(end - begin);
 364     NR::Point be = (end - begin) / length;
 365     double r = NR::dot(p - begin, be);
 366
 367     if (r < 0.0) return begin;
 368     if (r > length) return end;
 369
 370     double snapdist = length * snap;
 371     double r_snapped = (snap==0) ? r : floor(r/(snapdist + 0.5)) * snapdist;
 372
 373     return (begin + r_snapped * be);
 374 }
 375
 376 static void
 377 gr_knot_moved_handler(SPKnot *knot, NR::Point const *ppointer, guint state, gpointer data)
 378 {
 379     GrDragger *dragger = (GrDragger *) data;
 380     GrDrag *drag = dragger->parent;
 381
 382     NR::Point p = *ppointer;
 383
 384     // FIXME: take from prefs
 385     double snap_dist = SNAP_DIST / dragger->parent->desktop->current_zoom();
 386
 387     if (state & GDK_SHIFT_MASK) {
 388         // with Shift; unsnap if we carry more than one draggable
 389         if (dragger->draggables && dragger->draggables->next) {
 390             // create a new dragger
 391             GrDragger *dr_new = new GrDragger (dragger->parent, dragger->point, NULL);
 392             dragger->parent->draggers = g_list_prepend (dragger->parent->draggers, dr_new);
 393             // relink to it all but the first draggable in the list
 394             for (GSList const* i = dragger->draggables->next; i != NULL; i = i->next) {
 395                 GrDraggable *draggable = (GrDraggable *) i->data;
 396                 dr_new->addDraggable (draggable);
 397             }
 398             dr_new->updateKnotShape();
 399             g_slist_free (dragger->draggables->next);
 400             dragger->draggables->next = NULL;
 401             dragger->updateKnotShape();
 402             dragger->updateTip();
 403         }
 404     } else if (!(state & GDK_CONTROL_MASK)) {
 405         // without Shift or Ctrl; see if we need to snap to another dragger
 406         for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 407             GrDragger *d_new = (GrDragger *) di->data;
 408             if (dragger->mayMerge(d_new) && NR::L2 (d_new->point - p) < snap_dist) {
 409
 410                 // Merge draggers:
 411                 for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 412                     GrDraggable *draggable = (GrDraggable *) i->data;
 413                     // copy draggable to d_new:
 414                     GrDraggable *da_new = new GrDraggable (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 415                     d_new->addDraggable (da_new);
 416                 }
 417
 418                 // unlink and delete this dragger
 419                 dragger->parent->draggers = g_list_remove (dragger->parent->draggers, dragger);
 420                 delete dragger;
 421
 422                 // update the new merged dragger
 423                 d_new->fireDraggables(true, false, true);
 424                 d_new->parent->updateLines();
 425                 d_new->parent->setSelected (d_new);
 426                 d_new->updateKnotShape ();
 427                 d_new->updateTip ();
 428                 d_new->updateDependencies(true);
 429                 sp_document_done (sp_desktop_document (d_new->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 430                                   _("Merge gradient handles"));
 431                 return;
 432             }
 433         }
 434     }
 435
 436     if (!((state & GDK_SHIFT_MASK) || ((state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK)))) {
 437         // Try snapping to the grid or guides
 438         SnapManager const &m = dragger->parent->desktop->namedview->snap_manager;
 439         Inkscape::SnappedPoint s = m.freeSnap(Inkscape::Snapper::SNAP_POINT | Inkscape::Snapper::BBOX_POINT, p, NULL);
 440         if (s.getDistance() < 1e6) {
 441             p = s.getPoint();
 442             sp_knot_moveto (knot, &p);
 443         } else {
 444             // No snapping so far, let's see if we need to snap to any of the levels
 445             for (guint i = 0; i < dragger->parent->hor_levels.size(); i++) {
 446                 if (fabs(p[NR::Y] - dragger->parent->hor_levels[i]) < snap_dist) {
 447                     p[NR::Y] = dragger->parent->hor_levels[i];
 448                     sp_knot_moveto (knot, &p);
 449                 }
 450             }
 451             for (guint i = 0; i < dragger->parent->vert_levels.size(); i++) {
 452                 if (fabs(p[NR::X] - dragger->parent->vert_levels[i]) < snap_dist) {
 453                     p[NR::X] = dragger->parent->vert_levels[i];
 454                     sp_knot_moveto (knot, &p);
 455                 }
 456             }
 457         }
 458     }
 459
 460     if (state & GDK_CONTROL_MASK) {
 461         unsigned snaps = abs(prefs_get_int_attribute("options.rotationsnapsperpi", "value", 12));
 462         /* 0 means no snapping. */
 463
 464         // This list will store snap vectors from all draggables of dragger
 465         GSList *snap_vectors = NULL;
 466
 467         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) {
 468             GrDraggable *draggable = (GrDraggable *) i->data;
 469
 470             NR::Point *dr_snap = NULL;
 471
 472             if (draggable->point_type == POINT_LG_BEGIN || draggable->point_type == POINT_LG_END) {
 473                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 474                     GrDragger *d_new = (GrDragger *) di->data;
 475                     if (d_new == dragger)
 476                         continue;
 477                     if (d_new->isA (draggable->item,
 478                                     draggable->point_type == POINT_LG_BEGIN? POINT_LG_END : POINT_LG_BEGIN,
 479                                     draggable->point_i,
 480                                     draggable->fill_or_stroke)) {
 481                         // found the other end of the linear gradient;
 482                         if (state & GDK_SHIFT_MASK) {
 483                             // moving linear around center
 484                             NR::Point center = NR::Point (0.5*(d_new->point + dragger->point));
 485                             dr_snap = &center;
 486                         } else {
 487                             // moving linear around the other end
 488                             dr_snap = &d_new->point;
 489                         }
 490                     }
 491                 }
 492             } else if (draggable->point_type == POINT_RG_R1 || draggable->point_type == POINT_RG_R2 || draggable->point_type == POINT_RG_FOCUS) {
 493                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 494                     GrDragger *d_new = (GrDragger *) di->data;
 495                     if (d_new == dragger)
 496                         continue;
 497                     if (d_new->isA (draggable->item,
 498                                     POINT_RG_CENTER,
 499                                     draggable->point_i,
 500                                     draggable->fill_or_stroke)) {
 501                         // found the center of the radial gradient;
 502                         dr_snap = &(d_new->point);
 503                     }
 504                 }
 505             } else if (draggable->point_type == POINT_RG_CENTER) {
 506                 // radial center snaps to hor/vert relative to its original position
 507                 dr_snap = &(dragger->point_original);
 508             }
 509
 510             NR::Point *snap_vector = NULL;
 511             if (dr_snap) {
 512                 if (state & GDK_MOD1_MASK) {
 513                     // with Alt, snap to the original angle and its perpendiculars
 514                     snap_vector = get_snap_vector (p, *dr_snap, M_PI/2, NR::atan2 (dragger->point_original - *dr_snap));
 515                 } else {
 516                     // with Ctrl, snap to M_PI/snaps
 517                     snap_vector = get_snap_vector (p, *dr_snap, M_PI/snaps, 0);
 518                 }
 519             }
 520             if (snap_vector) {
 521                 snap_vectors = g_slist_prepend (snap_vectors, snap_vector);
 522             }
 523         }
 524
 525         // Move by the smallest of snap vectors:
 526         NR::Point move(9999, 9999);
 527         for (GSList const *i = snap_vectors; i != NULL; i = i->next) {
 528             NR::Point *snap_vector = (NR::Point *) i->data;
 529             if (NR::L2(*snap_vector) < NR::L2(move))
 530                 move = *snap_vector;
 531         }
 532         if (move[NR::X] < 9999) {
 533             p += move;
 534             sp_knot_moveto (knot, &p);
 535         }
 536
 537         g_slist_free(snap_vectors);
 538     }
 539
 540     dragger->point = p;
 541
 542     if ((state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK)) {
 543         dragger->fireDraggables (false, true);
 544     } else {
 545         dragger->fireDraggables (false);
 546     }
 547
 548     dragger->updateDependencies(false);
 549
 550     drag->keep_selection = (bool) g_list_find(drag->selected, dragger);
 551 }
 552
 553
 554 /**
 555 Called when a midpoint knot is dragged.
 556 */
 557 static void
 558 gr_knot_moved_midpoint_handler(SPKnot *knot, NR::Point const *ppointer, guint state, gpointer data)
 559 {
 560     GrDragger *dragger = (GrDragger *) data;
 561     GrDrag *drag = dragger->parent;
 562     // a midpoint dragger can (logically) only contain one GrDraggable
 563     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 564
 565     // FIXME: take from prefs
 566     double snap_fraction = 0.1;
 567
 568     NR::Point p = *ppointer;
 569     NR::Point begin(0,0), end(0,0);
 570
 571     SPObject *server;
 572     if (draggable->fill_or_stroke)
 573         server = SP_OBJECT_STYLE_FILL_SERVER (draggable->item);
 574     else
 575         server = SP_OBJECT_STYLE_STROKE_SERVER (draggable->item);
 576
 577
 578     // get begin and end points between which dragging is allowed:
 579     // the draglimits are between knot(lowest_i - 1) and knot(highest_i + 1)
 580     GSList *moving = NULL;
 581     moving = g_slist_append(moving, dragger);
 582
 583     guint lowest_i = draggable->point_i;
 584     guint highest_i = draggable->point_i;
 585     GrDragger *lowest_dragger = dragger;
 586     GrDragger *highest_dragger = dragger;
 587     bool is_selected = g_list_find(drag->selected, dragger);
 588     if (is_selected) {
 589         GrDragger* d_add;
 590         while ( true )
 591         {
 592             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 593             if ( d_add && g_list_find(drag->selected, d_add) ) {
 594                 lowest_i = lowest_i - 1;
 595                 moving = g_slist_prepend(moving, d_add);
 596                 lowest_dragger = d_add;
 597             } else {
 598                 break;
 599             }
 600         }
 601
 602         while ( true )
 603         {
 604             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 605             if ( d_add && g_list_find(drag->selected, d_add) ) {
 606                 highest_i = highest_i + 1;
 607                 moving = g_slist_append(moving, d_add);
 608                 highest_dragger = d_add;
 609             } else {
 610                 break;
 611             }
 612         }
 613     }
 614
 615     if ( SP_IS_LINEARGRADIENT(server) ) {
 616         GrDragger *d_temp;
 617         if (lowest_i == 1) {
 618             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke);
 619         } else {
 620             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, lowest_i - 1, draggable->fill_or_stroke);
 621         }
 622         if (d_temp) begin = d_temp->point;
 623
 624         d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, highest_i + 1, draggable->fill_or_stroke);
 625         if (d_temp == NULL) {
 626             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_END, 0, draggable->fill_or_stroke);
 627         }
 628         if (d_temp) end = d_temp->point;
 629     } else if ( SP_IS_RADIALGRADIENT(server) ) {
 630         GrDragger *d_temp;
 631         if (lowest_i == 1) {
 632             d_temp = drag->getDraggerFor (draggable->item, POINT_RG_CENTER, 0, draggable->fill_or_stroke);
 633         } else {
 634             d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 635         }
 636         if (d_temp) begin = d_temp->point;
 637
 638         d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 639         if (d_temp == NULL) {
 640             d_temp = drag->getDraggerFor (draggable->item, (draggable->point_type==POINT_RG_MID1) ? POINT_RG_R1 : POINT_RG_R2, 0, draggable->fill_or_stroke);
 641         }
 642         if (d_temp) end = d_temp->point;
 643     }
 644
 645     NR::Point low_lim  = dragger->point - (lowest_dragger->point - begin);
 646     NR::Point high_lim = dragger->point - (highest_dragger->point - end);
 647
 648     if (state & GDK_CONTROL_MASK) {
 649         p = snap_vector_midpoint (p, low_lim, high_lim, snap_fraction);
 650     } else {
 651         p = snap_vector_midpoint (p, low_lim, high_lim, 0);
 652     }
 653     NR::Point displacement = p - dragger->point;
 654
 655     for (GSList const* i = moving; i != NULL; i = i->next) {
 656         GrDragger *drg = (GrDragger*) i->data;
 657         SPKnot *drgknot = drg->knot;
 658         drg->point += displacement;
 659         sp_knot_moveto (drgknot, & drg->point);
 660         drg->fireDraggables (false);
 661         drg->updateDependencies(false);
 662     }
 663
 664     drag->keep_selection = is_selected;
 665 }
 666
 667
 668
 669 static void
 670 gr_knot_grabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 671 {
 672     GrDragger *dragger = (GrDragger *) data;
 673
 674     sp_canvas_force_full_redraw_after_interruptions(dragger->parent->desktop->canvas, 5);
 675 }
 676
 677 /**
 678 Called when the mouse releases a dragger knot; changes gradient writing to repr, updates other draggers if needed
 679 */
 680 static void
 681 gr_knot_ungrabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 682 {
 683     GrDragger *dragger = (GrDragger *) data;
 684
 685     sp_canvas_end_forced_full_redraws(dragger->parent->desktop->canvas);
 686
 687     dragger->point_original = dragger->point = knot->pos;
 688
 689     if ((state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK)) {
 690         dragger->fireDraggables (true, true);
 691     } else {
 692         dragger->fireDraggables (true);
 693     }
 694
 695     // make this dragger selected
 696     if (!dragger->parent->keep_selection) {
 697         dragger->parent->setSelected (dragger);
 698     }
 699     dragger->parent->keep_selection = false;
 700
 701     dragger->updateDependencies(true);
 702
 703     // we did an undoable action
 704     sp_document_done (sp_desktop_document (dragger->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 705                       _("Move gradient handle"));
 706 }
 707
 708 /**
 709 Called when a dragger knot is clicked; selects the dragger or deletes it depending on the
 710 state of the keyboard keys
 711 */
 712 static void
 713 gr_knot_clicked_handler(SPKnot *knot, guint state, gpointer data)
 714 {
 715     GrDragger *dragger = (GrDragger *) data;
 716     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 717     if (!draggable) return;
 718
 719     if ( (state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK ) ) {
 720     // delete this knot from vector
 721         SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
 722         gradient = sp_gradient_get_vector (gradient, false);
 723         if (gradient->vector.stops.size() > 2) { // 2 is the minimum
 724                 SPStop *stop = NULL;
 725                 switch (draggable->point_type) {  // if we delete first or last stop, move the next/previous to the edge
 726                 case POINT_LG_BEGIN:
 727                 case POINT_RG_CENTER:
 728                     stop = sp_first_stop(gradient);
 729                         {
 730                             SPStop *next = sp_next_stop (stop);
 731                                 if (next) {
 732                                         next->offset = 0;
 733                                         sp_repr_set_css_double (SP_OBJECT_REPR (next), "offset", 0);
 734                                 }
 735                         }
 736                     break;
 737                 case POINT_LG_END:
 738                 case POINT_RG_R1:
 739                 case POINT_RG_R2:
 740                     stop = sp_last_stop(gradient);
 741                     {
 742                             SPStop *prev = sp_prev_stop (stop, gradient);
 743                             if (prev) {
 744                                     prev->offset = 1;
 745                                     sp_repr_set_css_double (SP_OBJECT_REPR (prev), "offset", 1);
 746                             }
 747                         }
 748                     break;
 749                 case POINT_LG_MID:
 750                 case POINT_RG_MID1:
 751                 case POINT_RG_MID2:
 752                     stop = sp_get_stop_i(gradient, draggable->point_i);
 753                     break;
 754                 }
 755
 756                 SP_OBJECT_REPR(gradient)->removeChild(SP_OBJECT_REPR(stop));
 757                 sp_document_done (SP_OBJECT_DOCUMENT (gradient), SP_VERB_CONTEXT_GRADIENT,
 758                                   _("Delete gradient stop"));
 759         }
 760     } else {
 761     // select the dragger
 762         dragger->point_original = dragger->point;
 763
 764         if ( state & GDK_SHIFT_MASK ) {
 765             dragger->parent->setSelected (dragger, true, false);
 766         } else {
 767             dragger->parent->setSelected (dragger);
 768         }
 769     }
 770 }
 771
 772 /**
 773 Called when a dragger knot is doubleclicked; opens gradient editor with the stop from the first draggable
 774 */
 775 static void
 776 gr_knot_doubleclicked_handler (SPKnot *knot, guint state, gpointer data)
 777 {
 778     GrDragger *dragger = (GrDragger *) data;
 779
 780     dragger->point_original = dragger->point;
 781
 782     if (dragger->draggables == NULL)
 783         return;
 784
 785     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 786     sp_item_gradient_edit_stop (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 787 }
 788
 789 /**
 790 Act upon all draggables of the dragger, setting them to the dragger's point
 791 */
 792 void
 793 GrDragger::fireDraggables (bool write_repr, bool scale_radial, bool merging_focus)
 794 {
 795     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 796         GrDraggable *draggable = (GrDraggable *) i->data;
 797
 798         // set local_change flag so that selection_changed callback does not regenerate draggers
 799         this->parent->local_change = true;
 800
 801         // change gradient, optionally writing to repr; prevent focus from moving if it's snapped
 802         // to the center, unless it's the first update upon merge when we must snap it to the point
 803         if (merging_focus ||
 804             !(draggable->point_type == POINT_RG_FOCUS && this->isA(draggable->item, POINT_RG_CENTER, draggable->point_i, draggable->fill_or_stroke)))
 805         {
 806             sp_item_gradient_set_coords (draggable->item, draggable->point_type, draggable->point_i, this->point, draggable->fill_or_stroke, write_repr, scale_radial);
 807         }
 808     }
 809 }
 810
 811 /**
 812 Checks if the dragger has a draggable with this point_type
 813  */
 814 bool
 815 GrDragger::isA (guint point_type)
 816 {
 817     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 818         GrDraggable *draggable = (GrDraggable *) i->data;
 819         if (draggable->point_type == point_type) {
 820             return true;
 821         }
 822     }
 823     return false;
 824 }
 825
 826 /**
 827 Checks if the dragger has a draggable with this item, point_type, fill_or_stroke
 828  */
 829 bool
 830 GrDragger::isA (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke)
 831 {
 832     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 833         GrDraggable *draggable = (GrDraggable *) i->data;
 834         if ( (draggable->point_type == point_type) && (draggable->point_i == point_i) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
 835             return true;
 836         }
 837     }
 838     return false;
 839 }
 840
 841 bool
 842 GrDraggable::mayMerge (GrDraggable *da2)
 843 {
 844     if ((this->item == da2->item) && (this->fill_or_stroke == da2->fill_or_stroke)) {
 845         // we must not merge the points of the same gradient!
 846         if (!((this->point_type == POINT_RG_FOCUS && da2->point_type == POINT_RG_CENTER) ||
 847               (this->point_type == POINT_RG_CENTER && da2->point_type == POINT_RG_FOCUS))) {
 848             // except that we can snap center and focus together
 849             return false;
 850         }
 851     }
 852     // disable merging of midpoints.
 853     if ( (this->point_type == POINT_LG_MID) || (da2->point_type == POINT_LG_MID)
 854          || (this->point_type == POINT_RG_MID1) || (da2->point_type == POINT_RG_MID1)
 855          || (this->point_type == POINT_RG_MID2) || (da2->point_type == POINT_RG_MID2) )
 856         return false;
 857
 858     return true;
 859 }
 860
 861 bool
 862 GrDragger::mayMerge (GrDragger *other)
 863 {
 864     if (this == other)
 865         return false;
 866
 867     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
 868         GrDraggable *da1 = (GrDraggable *) i->data;
 869         for (GSList const* j = other->draggables; j != NULL; j = j->next) { // for all draggables of other
 870             GrDraggable *da2 = (GrDraggable *) j->data;
 871             if (!da1->mayMerge(da2))
 872                 return false;
 873         }
 874     }
 875     return true;
 876 }
 877
 878 bool
 879 GrDragger::mayMerge (GrDraggable *da2)
 880 {
 881     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
 882         GrDraggable *da1 = (GrDraggable *) i->data;
 883         if (!da1->mayMerge(da2))
 884             return false;
 885     }
 886     return true;
 887 }
 888
 889 /**
 890 Updates the statusbar tip of the dragger knot, based on its draggables
 891  */
 892 void
 893 GrDragger::updateTip ()
 894 {
 895         if (this->knot && this->knot->tip) {
 896                 g_free (this->knot->tip);
 897                 this->knot->tip = NULL;
 898         }
 899
 900     if (g_slist_length (this->draggables) == 1) {
 901         GrDraggable *draggable = (GrDraggable *) this->draggables->data;
 902         char *item_desc = sp_item_description(draggable->item);
 903         switch (draggable->point_type) {
 904             case POINT_LG_MID:
 905             case POINT_RG_MID1:
 906             case POINT_RG_MID2:
 907                 this->knot->tip = g_strdup_printf (_("%s %d for: %s%s; drag with <b>Ctrl</b> to snap offset; click with <b>Ctrl+Alt</b> to delete stop"),
 908                                                    _(gr_knot_descr[draggable->point_type]),
 909                                                    draggable->point_i,
 910                                                    item_desc,
 911                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
 912                 break;
 913
 914             default:
 915                 this->knot->tip = g_strdup_printf (_("%s for: %s%s; drag with <b>Ctrl</b> to snap angle, with <b>Ctrl+Alt</b> to preserve angle, with <b>Ctrl+Shift</b> to scale around center"),
 916                                                    _(gr_knot_descr[draggable->point_type]),
 917                                                    item_desc,
 918                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
 919                 break;
 920         }
 921         g_free(item_desc);
 922     } else if (g_slist_length (draggables) == 2 && isA (POINT_RG_CENTER) && isA (POINT_RG_FOCUS)) {
 923         this->knot->tip = g_strdup_printf (_("Radial gradient <b>center</b> and <b>focus</b>; drag with <b>Shift</b> to separate focus"));
 924     } else {
 925         int length = g_slist_length (this->draggables);
 926         this->knot->tip = g_strdup_printf (ngettext("Gradient point shared by <b>%d</b> gradient; drag with <b>Shift</b> to separate",
 927                                                     "Gradient point shared by <b>%d</b> gradients; drag with <b>Shift</b> to separate",
 928                                                     length),
 929                                            length);
 930     }
 931 }
 932
 933 /**
 934 Adds a draggable to the dragger
 935  */
 936 void
 937 GrDragger::updateKnotShape ()
 938 {
 939     if (!draggables)
 940         return;
 941     GrDraggable *last = (GrDraggable *) g_slist_last(draggables)->data;
 942     g_object_set (G_OBJECT (this->knot->item), "shape", gr_knot_shapes[last->point_type], NULL);
 943 }
 944
 945 /**
 946 Adds a draggable to the dragger
 947  */
 948 void
 949 GrDragger::addDraggable (GrDraggable *draggable)
 950 {
 951     this->draggables = g_slist_prepend (this->draggables, draggable);
 952
 953     this->updateTip();
 954 }
 955
 956
 957 /**
 958 Moves this dragger to the point of the given draggable, acting upon all other draggables
 959  */
 960 void
 961 GrDragger::moveThisToDraggable (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke, bool write_repr)
 962 {
 963     this->point = sp_item_gradient_get_coords (item, point_type, point_i, fill_or_stroke);
 964     this->point_original = this->point;
 965
 966     sp_knot_moveto (this->knot, &(this->point));
 967
 968     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 969         GrDraggable *da = (GrDraggable *) i->data;
 970         if ( (da->item == item) && (da->point_type == point_type) && (da->point_i == point_i) && (da->fill_or_stroke == fill_or_stroke) ) {
 971             continue;
 972         }
 973         sp_item_gradient_set_coords (da->item, da->point_type, da->point_i, this->point, da->fill_or_stroke, write_repr, false);
 974     }
 975     // FIXME: here we should also call this->updateDependencies(write_repr); to propagate updating, but how to prevent loops?
 976 }
 977
 978
 979 /**
 980 Moves all midstop draggables that depend on this one
 981  */
 982 void
 983 GrDragger::updateMidstopDependencies (GrDraggable *draggable, bool write_repr) {
 984     SPObject *server;
 985     if (draggable->fill_or_stroke)
 986         server = SP_OBJECT_STYLE_FILL_SERVER (draggable->item);
 987     else
 988         server = SP_OBJECT_STYLE_STROKE_SERVER (draggable->item);
 989     guint num = SP_GRADIENT(server)->vector.stops.size();
 990     if (num <= 2) return;
 991
 992     if ( SP_IS_LINEARGRADIENT(server) ) {
 993         for ( guint i = 1; i < num - 1; i++ ) {
 994             this->moveOtherToDraggable (draggable->item, POINT_LG_MID, i, draggable->fill_or_stroke, write_repr);
 995         }
 996     } else  if ( SP_IS_RADIALGRADIENT(server) ) {
 997         for ( guint i = 1; i < num - 1; i++ ) {
 998             this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, i, draggable->fill_or_stroke, write_repr);
 999             this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, i, draggable->fill_or_stroke, write_repr);
1000         }
1001     }
1002 }
1003
1004
1005 /**
1006 Moves all draggables that depend on this one
1007  */
1008 void
1009 GrDragger::updateDependencies (bool write_repr)
1010 {
1011     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1012         GrDraggable *draggable = (GrDraggable *) i->data;
1013         switch (draggable->point_type) {
1014             case POINT_LG_BEGIN:
1015                 {
1016                     // the end point is dependent only when dragging with ctrl+shift
1017                     this->moveOtherToDraggable (draggable->item, POINT_LG_END, 0, draggable->fill_or_stroke, write_repr);
1018
1019                     this->updateMidstopDependencies (draggable, write_repr);
1020                 }
1021                 break;
1022             case POINT_LG_END:
1023                 {
1024                     // the begin point is dependent only when dragging with ctrl+shift
1025                     this->moveOtherToDraggable (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke, write_repr);
1026
1027                     this->updateMidstopDependencies (draggable, write_repr);
1028                 }
1029                 break;
1030             case POINT_LG_MID:
1031                 // no other nodes depend on mid points.
1032                 break;
1033             case POINT_RG_R2:
1034                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, 0, draggable->fill_or_stroke, write_repr);
1035                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, 0, draggable->fill_or_stroke, write_repr);
1036                 this->updateMidstopDependencies (draggable, write_repr);
1037                 break;
1038             case POINT_RG_R1:
1039                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, 0, draggable->fill_or_stroke, write_repr);
1040                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, 0, draggable->fill_or_stroke, write_repr);
1041                 this->updateMidstopDependencies (draggable, write_repr);
1042                 break;
1043             case POINT_RG_CENTER:
1044                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, 0, draggable->fill_or_stroke, write_repr);
1045                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, 0, draggable->fill_or_stroke, write_repr);
1046                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, 0, draggable->fill_or_stroke, write_repr);
1047                 this->updateMidstopDependencies (draggable, write_repr);
1048                 break;
1049             case POINT_RG_FOCUS:
1050                 // nothing can depend on that
1051                 break;
1052             case POINT_RG_MID1:
1053                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, draggable->point_i, draggable->fill_or_stroke, write_repr);
1054                 break;
1055             case POINT_RG_MID2:
1056                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, draggable->point_i, draggable->fill_or_stroke, write_repr);
1057                 break;
1058             default:
1059                 break;
1060         }
1061     }
1062 }
1063
1064
1065
1066 GrDragger::GrDragger (GrDrag *parent, NR::Point p, GrDraggable *draggable)
1067 {
1068     this->draggables = NULL;
1069
1070     this->parent = parent;
1071
1072     this->point = p;
1073     this->point_original = p;
1074
1075     // create the knot
1076     this->knot = sp_knot_new (parent->desktop, NULL);
1077     this->knot->setMode(SP_KNOT_MODE_XOR);
1078     this->knot->setFill(GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_NORMAL);
1079     this->knot->setStroke(0x000000ff, 0x000000ff, 0x000000ff);
1080     sp_knot_update_ctrl(this->knot);
1081
1082     // move knot to the given point
1083     sp_knot_set_position (this->knot, &p, SP_KNOT_STATE_NORMAL);
1084     sp_knot_show (this->knot);
1085
1086     // connect knot's signals
1087     if ( (draggable)  // it can be NULL if a node in unsnapped (eg. focus point unsnapped from center)
1088                        // luckily, midstops never snap to other nodes so are never unsnapped...
1089          && ( (draggable->point_type == POINT_LG_MID)
1090               || (draggable->point_type == POINT_RG_MID1)
1091               || (draggable->point_type == POINT_RG_MID2) ) )
1092     {
1093         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_midpoint_handler), this);
1094     } else {
1095         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_handler), this);
1096     }
1097     g_signal_connect (G_OBJECT (this->knot), "clicked", G_CALLBACK (gr_knot_clicked_handler), this);
1098     g_signal_connect (G_OBJECT (this->knot), "doubleclicked", G_CALLBACK (gr_knot_doubleclicked_handler), this);
1099     g_signal_connect (G_OBJECT (this->knot), "grabbed", G_CALLBACK (gr_knot_grabbed_handler), this);
1100     g_signal_connect (G_OBJECT (this->knot), "ungrabbed", G_CALLBACK (gr_knot_ungrabbed_handler), this);
1101
1102     // add the initial draggable
1103     if (draggable)
1104         this->addDraggable (draggable);
1105     updateKnotShape();
1106 }
1107
1108 GrDragger::~GrDragger ()
1109 {
1110     // unselect if it was selected
1111     this->parent->setDeselected(this);
1112
1113     // disconnect signals
1114     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_moved_handler), this);
1115     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_clicked_handler), this);
1116     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_doubleclicked_handler), this);
1117     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_grabbed_handler), this);
1118     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_ungrabbed_handler), this);
1119
1120     /* unref should call destroy */
1121     g_object_unref (G_OBJECT (this->knot));
1122
1123     // delete all draggables
1124     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1125         delete ((GrDraggable *) i->data);
1126     }
1127     g_slist_free (this->draggables);
1128     this->draggables = NULL;
1129 }
1130
1131 /**
1132 Select the dragger which has the given draggable.
1133 */
1134 GrDragger *
1135 GrDrag::getDraggerFor (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke)
1136 {
1137     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1138         GrDragger *dragger = (GrDragger *) i->data;
1139         for (GSList const* j = dragger->draggables; j != NULL; j = j->next) {
1140             GrDraggable *da2 = (GrDraggable *) j->data;
1141             if ( (da2->item == item) && (da2->point_type == point_type) && (da2->point_i == point_i) && (da2->fill_or_stroke == fill_or_stroke)) {
1142                 return (dragger);
1143             }
1144         }
1145     }
1146     return NULL;
1147 }
1148
1149
1150 void
1151 GrDragger::moveOtherToDraggable (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke, bool write_repr)
1152 {
1153     GrDragger *d = this->parent->getDraggerFor (item, point_type, point_i, fill_or_stroke);
1154     if (d && d !=  this) {
1155         d->moveThisToDraggable (item, point_type, point_i, fill_or_stroke, write_repr);
1156     }
1157 }
1158
1159
1160 /**
1161   Draw this dragger as selected
1162 */
1163 void
1164 GrDragger::select()
1165 {
1166     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_SELECTED;
1167     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_SELECTED, NULL);
1168 }
1169
1170 /**
1171   Draw this dragger as normal (deselected)
1172 */
1173 void
1174 GrDragger::deselect()
1175 {
1176     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_NORMAL;
1177     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_NORMAL, NULL);
1178 }
1179
1180
1181
1182 /**
1183 \brief Deselect all stops/draggers (private)
1184 */
1185 void
1186 GrDrag::deselect_all()
1187 {
1188     while (selected) {
1189         ( (GrDragger*) selected->data)->deselect();
1190         selected = g_list_remove(selected, selected->data);
1191     }
1192 }
1193
1194 /**
1195 \brief Deselect all stops/draggers (public; emits signal)
1196 */
1197 void
1198 GrDrag::deselectAll()
1199 {
1200     deselect_all();
1201     this->desktop->emitToolSubselectionChanged(NULL);
1202 }
1203
1204
1205 /**
1206 \brief Select a dragger
1207 \param dragger       The dragger to select
1208 \param add_to_selection   If true, add to selection, otherwise deselect others
1209 \param override      If true, always select this node, otherwise toggle selected status
1210 */
1211 void
1212 GrDrag::setSelected (GrDragger *dragger, bool add_to_selection, bool override)
1213 {
1214     GrDragger *seldragger = NULL;
1215
1216     if (add_to_selection) {
1217         if (!dragger) return;
1218         if (override) {
1219             if (!g_list_find(selected, dragger)) {
1220                 selected = g_list_prepend(selected, dragger);
1221             }
1222             dragger->select();
1223             seldragger = dragger;
1224         } else { // toggle
1225             if (g_list_find(selected, dragger)) {
1226                 selected = g_list_remove(selected, dragger);
1227                 dragger->deselect();
1228                 if (selected) {
1229                     seldragger = (GrDragger*) selected->data; // select the dragger that is first in the list
1230                 }
1231             } else {
1232                 selected = g_list_prepend(selected, dragger);
1233                 dragger->select();
1234                 seldragger = dragger;
1235             }
1236         }
1237     } else {
1238         deselect_all();
1239         if (dragger) {
1240             selected = g_list_prepend(selected, dragger);
1241             dragger->select();
1242             seldragger = dragger;
1243         }
1244     }
1245     if (seldragger) {
1246         this->desktop->emitToolSubselectionChanged((gpointer) seldragger);
1247     }
1248 }
1249
1250 /**
1251 \brief Deselect a dragger
1252 \param dragger       The dragger to deselect
1253 */
1254 void
1255 GrDrag::setDeselected (GrDragger *dragger)
1256 {
1257     if (g_list_find(selected, dragger)) {
1258         selected = g_list_remove(selected, dragger);
1259         dragger->deselect();
1260     }
1261     this->desktop->emitToolSubselectionChanged((gpointer) (selected ? selected->data : NULL ));
1262 }
1263
1264
1265
1266 /**
1267 Create a line from p1 to p2 and add it to the lines list
1268  */
1269 void
1270 GrDrag::addLine (NR::Point p1, NR::Point p2, guint32 rgba)
1271 {
1272     SPCanvasItem *line = sp_canvas_item_new(sp_desktop_controls(this->desktop),
1273                                                             SP_TYPE_CTRLLINE, NULL);
1274     sp_ctrlline_set_coords(SP_CTRLLINE(line), p1, p2);
1275     if (rgba != GR_LINE_COLOR_FILL) // fill is the default, so don't set color for it to speed up redraw
1276         sp_ctrlline_set_rgba32 (SP_CTRLLINE(line), rgba);
1277     sp_canvas_item_show (line);
1278     this->lines = g_slist_append (this->lines, line);
1279 }
1280
1281 /**
1282 If there already exists a dragger within MERGE_DIST of p, add the draggable to it; otherwise create
1283 new dragger and add it to draggers list
1284  */
1285 void
1286 GrDrag::addDragger (GrDraggable *draggable)
1287 {
1288     NR::Point p = sp_item_gradient_get_coords (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
1289
1290     for (GList *i = this->draggers; i != NULL; i = i->next) {
1291         GrDragger *dragger = (GrDragger *) i->data;
1292         if (dragger->mayMerge (draggable) && NR::L2 (dragger->point - p) < MERGE_DIST) {
1293             // distance is small, merge this draggable into dragger, no need to create new dragger
1294             dragger->addDraggable (draggable);
1295             dragger->updateKnotShape();
1296             return;
1297         }
1298     }
1299
1300     GrDragger *new_dragger = new GrDragger(this, p, draggable);
1301     // fixme: draggers should be added AFTER the last one: this way tabbing through them will be from begin to end.
1302     this->draggers = g_list_append (this->draggers, new_dragger);
1303 }
1304
1305 /**
1306 Add draggers for the radial gradient rg on item
1307 */
1308 void
1309 GrDrag::addDraggersRadial (SPRadialGradient *rg, SPItem *item, bool fill_or_stroke)
1310 {
1311     addDragger (new GrDraggable (item, POINT_RG_CENTER, 0, fill_or_stroke));
1312     guint num = rg->vector.stops.size();
1313     if (num > 2) {
1314         for ( guint i = 1; i < num - 1; i++ ) {
1315             addDragger (new GrDraggable (item, POINT_RG_MID1, i, fill_or_stroke));
1316         }
1317     }
1318     addDragger (new GrDraggable (item, POINT_RG_R1, 0, fill_or_stroke));
1319     if (num > 2) {
1320         for ( guint i = 1; i < num - 1; i++ ) {
1321             addDragger (new GrDraggable (item, POINT_RG_MID2, i, fill_or_stroke));
1322         }
1323     }
1324     addDragger (new GrDraggable (item, POINT_RG_R2, 0, fill_or_stroke));
1325     addDragger (new GrDraggable (item, POINT_RG_FOCUS, 0, fill_or_stroke));
1326 }
1327
1328 /**
1329 Add draggers for the linear gradient lg on item
1330 */
1331 void
1332 GrDrag::addDraggersLinear (SPLinearGradient *lg, SPItem *item, bool fill_or_stroke)
1333 {
1334     addDragger (new GrDraggable (item, POINT_LG_BEGIN, 0, fill_or_stroke));
1335     guint num = lg->vector.stops.size();
1336     if (num > 2) {
1337         for ( guint i = 1; i < num - 1; i++ ) {
1338             addDragger (new GrDraggable (item, POINT_LG_MID, i, fill_or_stroke));
1339         }
1340     }
1341     addDragger (new GrDraggable (item, POINT_LG_END, 0, fill_or_stroke));
1342 }
1343
1344 /**
1345 Artificially grab the knot of the dragger with this draggable; used by the gradient context
1346 */
1347 void
1348 GrDrag::grabKnot (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke, gint x, gint y, guint32 etime)
1349 {
1350     GrDragger *dragger = getDraggerFor (item, point_type, point_i, fill_or_stroke);
1351     if (dragger) {
1352         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1353     }
1354 }
1355
1356 /**
1357 Regenerates the draggers list from the current selection; is called when selection is changed or
1358 modified, also when a radial dragger needs to update positions of other draggers in the gradient
1359 */
1360 void
1361 GrDrag::updateDraggers ()
1362 {
1363     while (selected) {
1364         selected = g_list_remove(selected, selected->data);
1365     }
1366     // delete old draggers
1367     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1368         delete ((GrDragger *) i->data);
1369     }
1370     g_list_free (this->draggers);
1371     this->draggers = NULL;
1372
1373     g_return_if_fail (this->selection != NULL);
1374
1375     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1376
1377         SPItem *item = SP_ITEM(i->data);
1378         SPStyle *style = SP_OBJECT_STYLE (item);
1379
1380         if (style && (style->fill.type == SP_PAINT_TYPE_PAINTSERVER)) {
1381             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1382             if (SP_IS_LINEARGRADIENT (server)) {
1383                 addDraggersLinear (SP_LINEARGRADIENT (server), item, true);
1384             } else if (SP_IS_RADIALGRADIENT (server)) {
1385                 addDraggersRadial (SP_RADIALGRADIENT (server), item, true);
1386             }
1387         }
1388
1389         if (style && (style->stroke.type == SP_PAINT_TYPE_PAINTSERVER)) {
1390             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1391             if (SP_IS_LINEARGRADIENT (server)) {
1392                 addDraggersLinear (SP_LINEARGRADIENT (server), item, false);
1393             } else if (SP_IS_RADIALGRADIENT (server)) {
1394                 addDraggersRadial (SP_RADIALGRADIENT (server), item, false);
1395             }
1396         }
1397     }
1398 }
1399
1400 /**
1401 Regenerates the lines list from the current selection; is called on each move of a dragger, so that
1402 lines are always in sync with the actual gradient
1403 */
1404 void
1405 GrDrag::updateLines ()
1406 {
1407     // delete old lines
1408     for (GSList const *i = this->lines; i != NULL; i = i->next) {
1409         gtk_object_destroy( GTK_OBJECT (i->data));
1410     }
1411     g_slist_free (this->lines);
1412     this->lines = NULL;
1413
1414     g_return_if_fail (this->selection != NULL);
1415
1416     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1417
1418         SPItem *item = SP_ITEM(i->data);
1419
1420         SPStyle *style = SP_OBJECT_STYLE (item);
1421
1422         if (style && (style->fill.type == SP_PAINT_TYPE_PAINTSERVER)) {
1423             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1424             if (SP_IS_LINEARGRADIENT (server)) {
1425                 this->addLine (sp_item_gradient_get_coords (item, POINT_LG_BEGIN, 0, true), sp_item_gradient_get_coords (item, POINT_LG_END, 0, true), GR_LINE_COLOR_FILL);
1426             } else if (SP_IS_RADIALGRADIENT (server)) {
1427                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, true);
1428                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, true), GR_LINE_COLOR_FILL);
1429                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, true), GR_LINE_COLOR_FILL);
1430             }
1431         }
1432
1433         if (style && (style->stroke.type == SP_PAINT_TYPE_PAINTSERVER)) {
1434             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1435             if (SP_IS_LINEARGRADIENT (server)) {
1436                 this->addLine (sp_item_gradient_get_coords (item, POINT_LG_BEGIN, 0, false), sp_item_gradient_get_coords (item, POINT_LG_END, 0, false), GR_LINE_COLOR_STROKE);
1437             } else if (SP_IS_RADIALGRADIENT (server)) {
1438                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, false);
1439                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, false), GR_LINE_COLOR_STROKE);
1440                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, false), GR_LINE_COLOR_STROKE);
1441             }
1442         }
1443     }
1444 }
1445
1446 /**
1447 Regenerates the levels list from the current selection
1448 */
1449 void
1450 GrDrag::updateLevels ()
1451 {
1452     hor_levels.clear();
1453     vert_levels.clear();
1454
1455     g_return_if_fail (this->selection != NULL);
1456
1457     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1458         SPItem *item = SP_ITEM(i->data);
1459         NR::Maybe<NR::Rect> rect = sp_item_bbox_desktop (item);
1460         if (rect) {
1461             // Remember the edges of the bbox and the center axis
1462             hor_levels.push_back(rect->min()[NR::Y]);
1463             hor_levels.push_back(rect->max()[NR::Y]);
1464             hor_levels.push_back(0.5 * (rect->min()[NR::Y] + rect->max()[NR::Y]));
1465             vert_levels.push_back(rect->min()[NR::X]);
1466             vert_levels.push_back(rect->max()[NR::X]);
1467             vert_levels.push_back(0.5 * (rect->min()[NR::X] + rect->max()[NR::X]));
1468         }
1469     }
1470 }
1471
1472 void
1473 GrDrag::selected_reverse_vector ()
1474 {
1475     if (selected == NULL)
1476         return;
1477
1478     for (GSList const* i = ( (GrDragger*) selected->data )->draggables; i != NULL; i = i->next) {
1479         GrDraggable *draggable = (GrDraggable *) i->data;
1480
1481         sp_item_gradient_reverse_vector (draggable->item, draggable->fill_or_stroke);
1482     }
1483 }
1484
1485 void
1486 GrDrag::selected_move (double x, double y)
1487 {
1488 /*
1489     if (selected == NULL)
1490         return;
1491
1492     if ( (g_list_length(selected) == 1) )
1493     selected->point += NR::Point (x, y);
1494     selected->point_original = selected->point;
1495     sp_knot_moveto (selected->knot, &(selected->point));
1496
1497     selected->fireDraggables (true);
1498
1499     selected->updateDependencies(true);
1500
1501     // we did an undoable action
1502     sp_document_done (sp_desktop_document (desktop), SP_VERB_CONTEXT_GRADIENT,
1503                       _("Move gradient handle"));
1504 */
1505 }
1506
1507 void
1508 GrDrag::selected_move_screen (double x, double y)
1509 {
1510     gdouble zoom = desktop->current_zoom();
1511     gdouble zx = x / zoom;
1512     gdouble zy = y / zoom;
1513
1514     selected_move (zx, zy);
1515 }
1516
1517 /**
1518 Select the knot next to the last selected one and deselect all other selected.
1519 */
1520 void
1521 GrDrag::select_next ()
1522 {
1523     if (selected == NULL || g_list_find(draggers, selected->data)->next == NULL) {
1524         if (draggers)
1525             setSelected ((GrDragger *) draggers->data);
1526     } else {
1527         setSelected ((GrDragger *) g_list_find(draggers, selected->data)->next->data);
1528     }
1529 }
1530
1531 /**
1532 Select the knot previous from the last selected one and deselect all other selected.
1533 */
1534 void
1535 GrDrag::select_prev ()
1536 {
1537     if (selected == NULL || g_list_find(draggers, selected->data)->prev == NULL) {
1538         if (draggers)
1539             setSelected ((GrDragger *) g_list_last (draggers)->data);
1540     } else {
1541         setSelected ((GrDragger *) g_list_find(draggers, selected->data)->prev->data);
1542     }
1543 }
1544
1545
1546 // FIXME: i.m.o. an ugly function that I just made to work, but... aargh! (Johan)
1547 void
1548 GrDrag::deleteSelected (bool just_one)
1549 {
1550     if (!selected) return;
1551
1552     SPDocument *document = false;
1553
1554     struct StructStopInfo {
1555         SPStop * spstop;
1556         GrDraggable * draggable;
1557         SPGradient * gradient;
1558         SPGradient * vector;
1559     };
1560
1561     GSList *midstoplist = NULL;  // list of stops that must be deleted (will be deleted first)
1562     GSList *endstoplist = NULL;  // list of stops that must be deleted
1563     while (selected) {
1564         GrDragger *dragger = (GrDragger*) selected->data;
1565         for (GSList * drgble = dragger->draggables; drgble != NULL; drgble = drgble->next) {
1566             GrDraggable *draggable = (GrDraggable*) drgble->data;
1567             SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
1568             SPGradient *vector   = sp_gradient_get_forked_vector_if_necessary (gradient, false);
1569
1570             switch (draggable->point_type) {
1571                 case POINT_LG_MID:
1572                 case POINT_RG_MID1:
1573                 case POINT_RG_MID2:
1574                     {
1575                         SPStop *stop = sp_get_stop_i(vector, draggable->point_i);
1576                         // check if already present in list. (e.g. when both RG_MID1 and RG_MID2 were selected)
1577                         bool present = false;
1578                         for (GSList const * l = midstoplist; l != NULL; l = l->next) {
1579                             if ( (SPStop*)l->data == stop ) {
1580                                 present = true;
1581                                 break; // no need to search further.
1582                             }
1583                         }
1584                         if (!present)
1585                             midstoplist = g_slist_append(midstoplist, stop);
1586                     }
1587                     break;
1588                 case POINT_LG_BEGIN:
1589                 case POINT_LG_END:
1590                 case POINT_RG_CENTER:
1591                 case POINT_RG_R1:
1592                 case POINT_RG_R2:
1593                     {
1594                         SPStop *stop = NULL;
1595                         if ( (draggable->point_type == POINT_LG_BEGIN) || (draggable->point_type == POINT_RG_CENTER) ) {
1596                             stop = sp_first_stop(vector);
1597                         } else {
1598                             stop = sp_last_stop(vector);
1599                         }
1600                         if (stop) {
1601                             StructStopInfo *stopinfo = new StructStopInfo;
1602                             stopinfo->spstop = stop;
1603                             stopinfo->draggable = draggable;
1604                             stopinfo->gradient = gradient;
1605                             stopinfo->vector = vector;
1606                             // check if already present in list. (e.g. when both R1 and R2 were selected)
1607                             bool present = false;
1608                             for (GSList const * l = endstoplist; l != NULL; l = l->next) {
1609                                 if ( ((StructStopInfo*)l->data)->spstop == stopinfo->spstop ) {
1610                                     present = true;
1611                                     break; // no need to search further.
1612                                 }
1613                             }
1614                             if (!present)
1615                                 endstoplist = g_slist_append(endstoplist, stopinfo);
1616                         }
1617                     }
1618                     break;
1619                 default:
1620                     break;
1621             }
1622         }
1623         selected = g_list_remove(selected, dragger);
1624         if ( just_one ) break; // iterate once if just_one is set.
1625     }
1626     while (midstoplist) {
1627         SPStop *stop = (SPStop*) midstoplist->data;
1628         document = SP_OBJECT_DOCUMENT (stop);
1629         Inkscape::XML::Node * parent = SP_OBJECT_REPR(stop)->parent();
1630         parent->removeChild(SP_OBJECT_REPR(stop));
1631         midstoplist = g_slist_remove(midstoplist, stop);
1632     }
1633     while (endstoplist) {
1634         StructStopInfo *stopinfo  = (StructStopInfo*) endstoplist->data;
1635         document = SP_OBJECT_DOCUMENT (stopinfo->spstop);
1636
1637         // 2 is the minimum, cannot delete more than that without deleting the whole vector
1638         // cannot use vector->vector.stops.size() because the vector might be invalidated by deletion of a midstop
1639         // manually count the children, don't know if there already exists a function for this...
1640         int len = 0;
1641         for ( SPObject *child = sp_object_first_child(stopinfo->vector) ;
1642               child != NULL ;
1643               child = SP_OBJECT_NEXT(child) )
1644         {
1645             if ( SP_IS_STOP(child) )  len ++;
1646         }
1647         if (len > 2)
1648         {
1649             switch (stopinfo->draggable->point_type) {
1650                 case POINT_LG_BEGIN:
1651                     {
1652                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1653
1654                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
1655                         NR::Point oldbegin = NR::Point (lg->x1.computed, lg->y1.computed);
1656                         NR::Point end = NR::Point (lg->x2.computed, lg->y2.computed);
1657                         SPStop *stop = sp_first_stop(stopinfo->vector);
1658                         gdouble offset = stop->offset;
1659                         NR::Point newbegin = oldbegin + offset * (end - oldbegin);
1660                         lg->x1.computed = newbegin[NR::X];
1661                         lg->y1.computed = newbegin[NR::Y];
1662
1663                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
1664                         sp_repr_set_svg_double(repr, "x1", lg->x1.computed);
1665                         sp_repr_set_svg_double(repr, "y1", lg->y1.computed);
1666                         stop->offset = 0;
1667                         sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", 0);
1668
1669                         // iterate through midstops to set new offset values such that they won't move on canvas.
1670                         SPStop *laststop = sp_last_stop(stopinfo->vector);
1671                         stop = sp_next_stop(stop);
1672                         while ( stop != laststop ) {
1673                             stop->offset = (stop->offset - offset)/(1 - offset);
1674                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
1675                             stop = sp_next_stop(stop);
1676                         }
1677                     }
1678                     break;
1679                 case POINT_LG_END:
1680                     {
1681                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1682
1683                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
1684                         NR::Point begin = NR::Point (lg->x1.computed, lg->y1.computed);
1685                         NR::Point oldend = NR::Point (lg->x2.computed, lg->y2.computed);
1686                         SPStop *laststop = sp_last_stop(stopinfo->vector);
1687                         gdouble offset = laststop->offset;
1688                         NR::Point newend = begin + offset * (oldend - begin);
1689                         lg->x2.computed = newend[NR::X];
1690                         lg->y2.computed = newend[NR::Y];
1691
1692                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
1693                         sp_repr_set_svg_double(repr, "x2", lg->x2.computed);
1694                         sp_repr_set_svg_double(repr, "y2", lg->y2.computed);
1695                         laststop->offset = 1;
1696                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
1697
1698                         // iterate through midstops to set new offset values such that they won't move on canvas.
1699                         SPStop *stop = sp_first_stop(stopinfo->vector);
1700                         stop = sp_next_stop(stop);
1701                         while ( stop != laststop ) {
1702                             stop->offset = stop->offset / offset;
1703                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
1704                             stop = sp_next_stop(stop);
1705                         }
1706                     }
1707                     break;
1708                 case POINT_RG_CENTER:
1709                     {
1710                         SPStop *newfirst = sp_next_stop (stopinfo->spstop);
1711                         if (newfirst) {
1712                             newfirst->offset = 0;
1713                             sp_repr_set_css_double (SP_OBJECT_REPR (newfirst), "offset", 0);
1714                         }
1715                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1716                     }
1717                     break;
1718                 case POINT_RG_R1:
1719                 case POINT_RG_R2:
1720                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1721
1722                         SPRadialGradient *rg = SP_RADIALGRADIENT(stopinfo->gradient);
1723                         double oldradius = rg->r.computed;
1724                         SPStop *laststop = sp_last_stop(stopinfo->vector);
1725                         gdouble offset = laststop->offset;
1726                         double newradius = offset * oldradius;
1727                         rg->r.computed = newradius;
1728
1729                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(rg);
1730                         sp_repr_set_svg_double(repr, "r", rg->r.computed);
1731                         laststop->offset = 1;
1732                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
1733
1734                         // iterate through midstops to set new offset values such that they won't move on canvas.
1735                         SPStop *stop = sp_first_stop(stopinfo->vector);
1736                         stop = sp_next_stop(stop);
1737                         while ( stop != laststop ) {
1738                             stop->offset = stop->offset / offset;
1739                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
1740                             stop = sp_next_stop(stop);
1741                         }
1742                         break;
1743             }
1744         }
1745         else
1746         { // delete the gradient from the object. set fill to unset  FIXME: set to fill of unselected node?
1747             SPCSSAttr *css = sp_repr_css_attr_new ();
1748
1749             // stopinfo->spstop is the selected stop
1750             Inkscape::XML::Node *unselectedrepr = SP_OBJECT_REPR(stopinfo->vector)->firstChild();
1751             if (unselectedrepr == SP_OBJECT_REPR(stopinfo->spstop) ) {
1752                 unselectedrepr = unselectedrepr->next();
1753             }
1754
1755             if (unselectedrepr == NULL) {
1756                 if (stopinfo->draggable->fill_or_stroke) {
1757                     sp_repr_css_unset_property (css, "fill");
1758                 } else {
1759                     sp_repr_css_unset_property (css, "stroke");
1760                 }
1761             } else {
1762                 SPCSSAttr *stopcss = sp_repr_css_attr(unselectedrepr, "style");
1763                 if (stopinfo->draggable->fill_or_stroke) {
1764                     sp_repr_css_set_property(css, "fill", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
1765                     sp_repr_css_set_property(css, "fill-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
1766                 } else {
1767                     sp_repr_css_set_property(css, "stroke", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
1768                     sp_repr_css_set_property(css, "stroke-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
1769                 }
1770                 sp_repr_css_attr_unref (stopcss);
1771             }
1772
1773             sp_repr_css_change (SP_OBJECT_REPR (stopinfo->draggable->item), css, "style");
1774             sp_repr_css_attr_unref (css);
1775         }
1776
1777         endstoplist = g_slist_remove(endstoplist, stopinfo);
1778         delete stopinfo;
1779     }
1780
1781     if (document) {
1782         sp_document_done ( document, SP_VERB_CONTEXT_GRADIENT, _("Delete gradient stop(s)") );
1783     }
1784 }
1785
1786
1787 /*
1788   Local Variables:
1789   mode:c++
1790   c-file-style:"stroustrup"
1791   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1792   indent-tabs-mode:nil
1793   fill-column:99
1794   End:
1795 */
1796 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :