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             style->fill.clear();
 157             style->fill.setColor( cf[0], cf[1], cf[2] );
 158             style->fill.set = TRUE;
 159             style->stroke.clear();
 160             style->stroke.setColor( cf[0], cf[1], cf[2] );
 161             style->stroke.set = TRUE;
 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::SNAPPOINT_NODE, 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     drag->keep_selection = (bool) g_list_find(drag->selected, dragger);
 541     bool scale_radial = (state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK);
 542
 543     if (drag->keep_selection) {
 544         NR::Point diff = p - dragger->point;
 545         drag->selected_move_nowrite (diff[NR::X], diff[NR::Y], scale_radial);
 546     } else {
 547         dragger->point = p;
 548         dragger->fireDraggables (false, scale_radial);
 549         dragger->updateDependencies(false);
 550     }
 551
 552 }
 553
 554
 555 /**
 556 Called when a midpoint knot is dragged.
 557 */
 558 static void
 559 gr_knot_moved_midpoint_handler(SPKnot *knot, NR::Point const *ppointer, guint state, gpointer data)
 560 {
 561     GrDragger *dragger = (GrDragger *) data;
 562     GrDrag *drag = dragger->parent;
 563     // a midpoint dragger can (logically) only contain one GrDraggable
 564     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 565
 566     // FIXME: take from prefs
 567     double snap_fraction = 0.1;
 568
 569     NR::Point p = *ppointer;
 570     NR::Point begin(0,0), end(0,0);
 571
 572     SPObject *server;
 573     if (draggable->fill_or_stroke)
 574         server = SP_OBJECT_STYLE_FILL_SERVER (draggable->item);
 575     else
 576         server = SP_OBJECT_STYLE_STROKE_SERVER (draggable->item);
 577
 578
 579     // get begin and end points between which dragging is allowed:
 580     // the draglimits are between knot(lowest_i - 1) and knot(highest_i + 1)
 581     GSList *moving = NULL;
 582     moving = g_slist_append(moving, dragger);
 583
 584     guint lowest_i = draggable->point_i;
 585     guint highest_i = draggable->point_i;
 586     GrDragger *lowest_dragger = dragger;
 587     GrDragger *highest_dragger = dragger;
 588     bool is_selected = g_list_find(drag->selected, dragger);
 589     if (is_selected) {
 590         GrDragger* d_add;
 591         while ( true )
 592         {
 593             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 594             if ( d_add && g_list_find(drag->selected, d_add) ) {
 595                 lowest_i = lowest_i - 1;
 596                 moving = g_slist_prepend(moving, d_add);
 597                 lowest_dragger = d_add;
 598             } else {
 599                 break;
 600             }
 601         }
 602
 603         while ( true )
 604         {
 605             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 606             if ( d_add && g_list_find(drag->selected, d_add) ) {
 607                 highest_i = highest_i + 1;
 608                 moving = g_slist_append(moving, d_add);
 609                 highest_dragger = d_add;
 610             } else {
 611                 break;
 612             }
 613         }
 614     }
 615
 616     if ( SP_IS_LINEARGRADIENT(server) ) {
 617         guint num = SP_LINEARGRADIENT(server)->vector.stops.size();
 618         GrDragger *d_temp;
 619         if (lowest_i == 1) {
 620             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke);
 621         } else {
 622             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, lowest_i - 1, draggable->fill_or_stroke);
 623         }
 624         if (d_temp) begin = d_temp->point;
 625
 626         d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, highest_i + 1, draggable->fill_or_stroke);
 627         if (d_temp == NULL) {
 628             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_END, num-1, draggable->fill_or_stroke);
 629         }
 630         if (d_temp) end = d_temp->point;
 631     } else if ( SP_IS_RADIALGRADIENT(server) ) {
 632         guint num = SP_RADIALGRADIENT(server)->vector.stops.size();
 633         GrDragger *d_temp;
 634         if (lowest_i == 1) {
 635             d_temp = drag->getDraggerFor (draggable->item, POINT_RG_CENTER, 0, draggable->fill_or_stroke);
 636         } else {
 637             d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 638         }
 639         if (d_temp) begin = d_temp->point;
 640
 641         d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 642         if (d_temp == NULL) {
 643             d_temp = drag->getDraggerFor (draggable->item, (draggable->point_type==POINT_RG_MID1) ? POINT_RG_R1 : POINT_RG_R2, num-1, draggable->fill_or_stroke);
 644         }
 645         if (d_temp) end = d_temp->point;
 646     }
 647
 648     NR::Point low_lim  = dragger->point - (lowest_dragger->point - begin);
 649     NR::Point high_lim = dragger->point - (highest_dragger->point - end);
 650
 651     if (state & GDK_CONTROL_MASK) {
 652         p = snap_vector_midpoint (p, low_lim, high_lim, snap_fraction);
 653     } else {
 654         p = snap_vector_midpoint (p, low_lim, high_lim, 0);
 655     }
 656     NR::Point displacement = p - dragger->point;
 657
 658     for (GSList const* i = moving; i != NULL; i = i->next) {
 659         GrDragger *drg = (GrDragger*) i->data;
 660         SPKnot *drgknot = drg->knot;
 661         drg->point += displacement;
 662         sp_knot_moveto (drgknot, & drg->point);
 663         drg->fireDraggables (false);
 664         drg->updateDependencies(false);
 665     }
 666
 667     drag->keep_selection = is_selected;
 668 }
 669
 670
 671
 672 static void
 673 gr_knot_grabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 674 {
 675     GrDragger *dragger = (GrDragger *) data;
 676
 677     sp_canvas_force_full_redraw_after_interruptions(dragger->parent->desktop->canvas, 5);
 678 }
 679
 680 /**
 681 Called when the mouse releases a dragger knot; changes gradient writing to repr, updates other draggers if needed
 682 */
 683 static void
 684 gr_knot_ungrabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 685 {
 686     GrDragger *dragger = (GrDragger *) data;
 687
 688     sp_canvas_end_forced_full_redraws(dragger->parent->desktop->canvas);
 689
 690     dragger->point_original = dragger->point = knot->pos;
 691
 692     if ((state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK)) {
 693         dragger->fireDraggables (true, true);
 694     } else {
 695         dragger->fireDraggables (true);
 696     }
 697
 698     // make this dragger selected
 699     if (!dragger->parent->keep_selection) {
 700         dragger->parent->setSelected (dragger);
 701     }
 702     dragger->parent->keep_selection = false;
 703
 704     dragger->updateDependencies(true);
 705
 706     // we did an undoable action
 707     sp_document_done (sp_desktop_document (dragger->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 708                       _("Move gradient handle"));
 709 }
 710
 711 /**
 712 Called when a dragger knot is clicked; selects the dragger or deletes it depending on the
 713 state of the keyboard keys
 714 */
 715 static void
 716 gr_knot_clicked_handler(SPKnot *knot, guint state, gpointer data)
 717 {
 718     GrDragger *dragger = (GrDragger *) data;
 719     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 720     if (!draggable) return;
 721
 722     if ( (state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK ) ) {
 723     // delete this knot from vector
 724         SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
 725         gradient = sp_gradient_get_vector (gradient, false);
 726         if (gradient->vector.stops.size() > 2) { // 2 is the minimum
 727                 SPStop *stop = NULL;
 728                 switch (draggable->point_type) {  // if we delete first or last stop, move the next/previous to the edge
 729                 case POINT_LG_BEGIN:
 730                 case POINT_RG_CENTER:
 731                     stop = sp_first_stop(gradient);
 732                         {
 733                             SPStop *next = sp_next_stop (stop);
 734                                 if (next) {
 735                                         next->offset = 0;
 736                                         sp_repr_set_css_double (SP_OBJECT_REPR (next), "offset", 0);
 737                                 }
 738                         }
 739                     break;
 740                 case POINT_LG_END:
 741                 case POINT_RG_R1:
 742                 case POINT_RG_R2:
 743                     stop = sp_last_stop(gradient);
 744                     {
 745                             SPStop *prev = sp_prev_stop (stop, gradient);
 746                             if (prev) {
 747                                     prev->offset = 1;
 748                                     sp_repr_set_css_double (SP_OBJECT_REPR (prev), "offset", 1);
 749                             }
 750                         }
 751                     break;
 752                 case POINT_LG_MID:
 753                 case POINT_RG_MID1:
 754                 case POINT_RG_MID2:
 755                     stop = sp_get_stop_i(gradient, draggable->point_i);
 756                     break;
 757                 }
 758
 759                 SP_OBJECT_REPR(gradient)->removeChild(SP_OBJECT_REPR(stop));
 760                 sp_document_done (SP_OBJECT_DOCUMENT (gradient), SP_VERB_CONTEXT_GRADIENT,
 761                                   _("Delete gradient stop"));
 762         }
 763     } else {
 764     // select the dragger
 765         dragger->point_original = dragger->point;
 766
 767         if ( state & GDK_SHIFT_MASK ) {
 768             dragger->parent->setSelected (dragger, true, false);
 769         } else {
 770             dragger->parent->setSelected (dragger);
 771         }
 772     }
 773 }
 774
 775 /**
 776 Called when a dragger knot is doubleclicked; opens gradient editor with the stop from the first draggable
 777 */
 778 static void
 779 gr_knot_doubleclicked_handler (SPKnot *knot, guint state, gpointer data)
 780 {
 781     GrDragger *dragger = (GrDragger *) data;
 782
 783     dragger->point_original = dragger->point;
 784
 785     if (dragger->draggables == NULL)
 786         return;
 787
 788     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 789     sp_item_gradient_edit_stop (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 790 }
 791
 792 /**
 793 Act upon all draggables of the dragger, setting them to the dragger's point
 794 */
 795 void
 796 GrDragger::fireDraggables (bool write_repr, bool scale_radial, bool merging_focus)
 797 {
 798     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 799         GrDraggable *draggable = (GrDraggable *) i->data;
 800
 801         // set local_change flag so that selection_changed callback does not regenerate draggers
 802         this->parent->local_change = true;
 803
 804         // change gradient, optionally writing to repr; prevent focus from moving if it's snapped
 805         // to the center, unless it's the first update upon merge when we must snap it to the point
 806         if (merging_focus ||
 807             !(draggable->point_type == POINT_RG_FOCUS && this->isA(draggable->item, POINT_RG_CENTER, draggable->point_i, draggable->fill_or_stroke)))
 808         {
 809             sp_item_gradient_set_coords (draggable->item, draggable->point_type, draggable->point_i, this->point, draggable->fill_or_stroke, write_repr, scale_radial);
 810         }
 811     }
 812 }
 813
 814 /**
 815 Checks if the dragger has a draggable with this point_type
 816  */
 817 bool
 818 GrDragger::isA (gint point_type)
 819 {
 820     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 821         GrDraggable *draggable = (GrDraggable *) i->data;
 822         if (draggable->point_type == point_type) {
 823             return true;
 824         }
 825     }
 826     return false;
 827 }
 828
 829 /**
 830 Checks if the dragger has a draggable with this item, point_type, fill_or_stroke
 831  */
 832 bool
 833 GrDragger::isA (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
 834 {
 835     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 836         GrDraggable *draggable = (GrDraggable *) i->data;
 837         if ( (draggable->point_type == point_type) && (draggable->point_i == point_i) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
 838             return true;
 839         }
 840     }
 841     return false;
 842 }
 843
 844 bool
 845 GrDraggable::mayMerge (GrDraggable *da2)
 846 {
 847     if ((this->item == da2->item) && (this->fill_or_stroke == da2->fill_or_stroke)) {
 848         // we must not merge the points of the same gradient!
 849         if (!((this->point_type == POINT_RG_FOCUS && da2->point_type == POINT_RG_CENTER) ||
 850               (this->point_type == POINT_RG_CENTER && da2->point_type == POINT_RG_FOCUS))) {
 851             // except that we can snap center and focus together
 852             return false;
 853         }
 854     }
 855     // disable merging of midpoints.
 856     if ( (this->point_type == POINT_LG_MID) || (da2->point_type == POINT_LG_MID)
 857          || (this->point_type == POINT_RG_MID1) || (da2->point_type == POINT_RG_MID1)
 858          || (this->point_type == POINT_RG_MID2) || (da2->point_type == POINT_RG_MID2) )
 859         return false;
 860
 861     return true;
 862 }
 863
 864 bool
 865 GrDragger::mayMerge (GrDragger *other)
 866 {
 867     if (this == other)
 868         return false;
 869
 870     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
 871         GrDraggable *da1 = (GrDraggable *) i->data;
 872         for (GSList const* j = other->draggables; j != NULL; j = j->next) { // for all draggables of other
 873             GrDraggable *da2 = (GrDraggable *) j->data;
 874             if (!da1->mayMerge(da2))
 875                 return false;
 876         }
 877     }
 878     return true;
 879 }
 880
 881 bool
 882 GrDragger::mayMerge (GrDraggable *da2)
 883 {
 884     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
 885         GrDraggable *da1 = (GrDraggable *) i->data;
 886         if (!da1->mayMerge(da2))
 887             return false;
 888     }
 889     return true;
 890 }
 891
 892 /**
 893 Updates the statusbar tip of the dragger knot, based on its draggables
 894  */
 895 void
 896 GrDragger::updateTip ()
 897 {
 898         if (this->knot && this->knot->tip) {
 899                 g_free (this->knot->tip);
 900                 this->knot->tip = NULL;
 901         }
 902
 903     if (g_slist_length (this->draggables) == 1) {
 904         GrDraggable *draggable = (GrDraggable *) this->draggables->data;
 905         char *item_desc = sp_item_description(draggable->item);
 906         switch (draggable->point_type) {
 907             case POINT_LG_MID:
 908             case POINT_RG_MID1:
 909             case POINT_RG_MID2:
 910                 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"),
 911                                                    _(gr_knot_descr[draggable->point_type]),
 912                                                    draggable->point_i,
 913                                                    item_desc,
 914                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
 915                 break;
 916
 917             default:
 918                 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"),
 919                                                    _(gr_knot_descr[draggable->point_type]),
 920                                                    item_desc,
 921                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
 922                 break;
 923         }
 924         g_free(item_desc);
 925     } else if (g_slist_length (draggables) == 2 && isA (POINT_RG_CENTER) && isA (POINT_RG_FOCUS)) {
 926         this->knot->tip = g_strdup_printf (_("Radial gradient <b>center</b> and <b>focus</b>; drag with <b>Shift</b> to separate focus"));
 927     } else {
 928         int length = g_slist_length (this->draggables);
 929         this->knot->tip = g_strdup_printf (ngettext("Gradient point shared by <b>%d</b> gradient; drag with <b>Shift</b> to separate",
 930                                                     "Gradient point shared by <b>%d</b> gradients; drag with <b>Shift</b> to separate",
 931                                                     length),
 932                                            length);
 933     }
 934 }
 935
 936 /**
 937 Adds a draggable to the dragger
 938  */
 939 void
 940 GrDragger::updateKnotShape ()
 941 {
 942     if (!draggables)
 943         return;
 944     GrDraggable *last = (GrDraggable *) g_slist_last(draggables)->data;
 945     g_object_set (G_OBJECT (this->knot->item), "shape", gr_knot_shapes[last->point_type], NULL);
 946 }
 947
 948 /**
 949 Adds a draggable to the dragger
 950  */
 951 void
 952 GrDragger::addDraggable (GrDraggable *draggable)
 953 {
 954     this->draggables = g_slist_prepend (this->draggables, draggable);
 955
 956     this->updateTip();
 957 }
 958
 959
 960 /**
 961 Moves this dragger to the point of the given draggable, acting upon all other draggables
 962  */
 963 void
 964 GrDragger::moveThisToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
 965 {
 966     this->point = sp_item_gradient_get_coords (item, point_type, point_i, fill_or_stroke);
 967     this->point_original = this->point;
 968
 969     sp_knot_moveto (this->knot, &(this->point));
 970
 971     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 972         GrDraggable *da = (GrDraggable *) i->data;
 973         if ( (da->item == item) &&
 974              (point_type == -1 || da->point_type == point_type) &&
 975              (point_i == -1 || da->point_i == point_i) &&
 976              (da->fill_or_stroke == fill_or_stroke) ) {
 977             continue;
 978         }
 979         sp_item_gradient_set_coords (da->item, da->point_type, da->point_i, this->point, da->fill_or_stroke, write_repr, false);
 980     }
 981     // FIXME: here we should also call this->updateDependencies(write_repr); to propagate updating, but how to prevent loops?
 982 }
 983
 984
 985 /**
 986 Moves all midstop draggables that depend on this one
 987  */
 988 void
 989 GrDragger::updateMidstopDependencies (GrDraggable *draggable, bool write_repr) {
 990     SPObject *server;
 991     if (draggable->fill_or_stroke)
 992         server = SP_OBJECT_STYLE_FILL_SERVER (draggable->item);
 993     else
 994         server = SP_OBJECT_STYLE_STROKE_SERVER (draggable->item);
 995     guint num = SP_GRADIENT(server)->vector.stops.size();
 996     if (num <= 2) return;
 997
 998     if ( SP_IS_LINEARGRADIENT(server) ) {
 999         for ( guint i = 1; i < num - 1; i++ ) {
1000             this->moveOtherToDraggable (draggable->item, POINT_LG_MID, i, draggable->fill_or_stroke, write_repr);
1001         }
1002     } else  if ( SP_IS_RADIALGRADIENT(server) ) {
1003         for ( guint i = 1; i < num - 1; i++ ) {
1004             this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, i, draggable->fill_or_stroke, write_repr);
1005             this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, i, draggable->fill_or_stroke, write_repr);
1006         }
1007     }
1008 }
1009
1010
1011 /**
1012 Moves all draggables that depend on this one
1013  */
1014 void
1015 GrDragger::updateDependencies (bool write_repr)
1016 {
1017     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1018         GrDraggable *draggable = (GrDraggable *) i->data;
1019         switch (draggable->point_type) {
1020             case POINT_LG_BEGIN:
1021                 {
1022                     // the end point is dependent only when dragging with ctrl+shift
1023                     this->moveOtherToDraggable (draggable->item, POINT_LG_END, -1, draggable->fill_or_stroke, write_repr);
1024
1025                     this->updateMidstopDependencies (draggable, write_repr);
1026                 }
1027                 break;
1028             case POINT_LG_END:
1029                 {
1030                     // the begin point is dependent only when dragging with ctrl+shift
1031                     this->moveOtherToDraggable (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke, write_repr);
1032
1033                     this->updateMidstopDependencies (draggable, write_repr);
1034                 }
1035                 break;
1036             case POINT_LG_MID:
1037                 // no other nodes depend on mid points.
1038                 break;
1039             case POINT_RG_R2:
1040                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1041                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1042                 this->updateMidstopDependencies (draggable, write_repr);
1043                 break;
1044             case POINT_RG_R1:
1045                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1046                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1047                 this->updateMidstopDependencies (draggable, write_repr);
1048                 break;
1049             case POINT_RG_CENTER:
1050                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1051                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1052                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1053                 this->updateMidstopDependencies (draggable, write_repr);
1054                 break;
1055             case POINT_RG_FOCUS:
1056                 // nothing can depend on that
1057                 break;
1058             case POINT_RG_MID1:
1059                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, draggable->point_i, draggable->fill_or_stroke, write_repr);
1060                 break;
1061             case POINT_RG_MID2:
1062                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, draggable->point_i, draggable->fill_or_stroke, write_repr);
1063                 break;
1064             default:
1065                 break;
1066         }
1067     }
1068 }
1069
1070
1071
1072 GrDragger::GrDragger (GrDrag *parent, NR::Point p, GrDraggable *draggable)
1073 {
1074     this->draggables = NULL;
1075
1076     this->parent = parent;
1077
1078     this->point = p;
1079     this->point_original = p;
1080
1081     // create the knot
1082     this->knot = sp_knot_new (parent->desktop, NULL);
1083     this->knot->setMode(SP_KNOT_MODE_XOR);
1084     this->knot->setFill(GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_NORMAL);
1085     this->knot->setStroke(0x000000ff, 0x000000ff, 0x000000ff);
1086     sp_knot_update_ctrl(this->knot);
1087
1088     // move knot to the given point
1089     sp_knot_set_position (this->knot, &p, SP_KNOT_STATE_NORMAL);
1090     sp_knot_show (this->knot);
1091
1092     // connect knot's signals
1093     if ( (draggable)  // it can be NULL if a node in unsnapped (eg. focus point unsnapped from center)
1094                        // luckily, midstops never snap to other nodes so are never unsnapped...
1095          && ( (draggable->point_type == POINT_LG_MID)
1096               || (draggable->point_type == POINT_RG_MID1)
1097               || (draggable->point_type == POINT_RG_MID2) ) )
1098     {
1099         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_midpoint_handler), this);
1100     } else {
1101         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_handler), this);
1102     }
1103     g_signal_connect (G_OBJECT (this->knot), "clicked", G_CALLBACK (gr_knot_clicked_handler), this);
1104     g_signal_connect (G_OBJECT (this->knot), "doubleclicked", G_CALLBACK (gr_knot_doubleclicked_handler), this);
1105     g_signal_connect (G_OBJECT (this->knot), "grabbed", G_CALLBACK (gr_knot_grabbed_handler), this);
1106     g_signal_connect (G_OBJECT (this->knot), "ungrabbed", G_CALLBACK (gr_knot_ungrabbed_handler), this);
1107
1108     // add the initial draggable
1109     if (draggable)
1110         this->addDraggable (draggable);
1111     updateKnotShape();
1112 }
1113
1114 GrDragger::~GrDragger ()
1115 {
1116     // unselect if it was selected
1117     this->parent->setDeselected(this);
1118
1119     // disconnect signals
1120     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_moved_handler), this);
1121     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_clicked_handler), this);
1122     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_doubleclicked_handler), this);
1123     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_grabbed_handler), this);
1124     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_ungrabbed_handler), this);
1125
1126     /* unref should call destroy */
1127     g_object_unref (G_OBJECT (this->knot));
1128
1129     // delete all draggables
1130     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1131         delete ((GrDraggable *) i->data);
1132     }
1133     g_slist_free (this->draggables);
1134     this->draggables = NULL;
1135 }
1136
1137 /**
1138 Select the dragger which has the given draggable.
1139 */
1140 GrDragger *
1141 GrDrag::getDraggerFor (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1142 {
1143     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1144         GrDragger *dragger = (GrDragger *) i->data;
1145         for (GSList const* j = dragger->draggables; j != NULL; j = j->next) {
1146             GrDraggable *da2 = (GrDraggable *) j->data;
1147             if ( (da2->item == item) &&
1148                  (point_type == -1 || da2->point_type == point_type) && // -1 means this does not matter
1149                  (point_i == -1 || da2->point_i == point_i) && // -1 means this does not matter
1150                  (da2->fill_or_stroke == fill_or_stroke)) {
1151                 return (dragger);
1152             }
1153         }
1154     }
1155     return NULL;
1156 }
1157
1158
1159 void
1160 GrDragger::moveOtherToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1161 {
1162     GrDragger *d = this->parent->getDraggerFor (item, point_type, point_i, fill_or_stroke);
1163     if (d && d !=  this) {
1164         d->moveThisToDraggable (item, point_type, point_i, fill_or_stroke, write_repr);
1165     }
1166 }
1167
1168
1169 /**
1170   Draw this dragger as selected
1171 */
1172 void
1173 GrDragger::select()
1174 {
1175     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_SELECTED;
1176     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_SELECTED, NULL);
1177 }
1178
1179 /**
1180   Draw this dragger as normal (deselected)
1181 */
1182 void
1183 GrDragger::deselect()
1184 {
1185     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_NORMAL;
1186     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_NORMAL, NULL);
1187 }
1188
1189 bool
1190 GrDragger::isSelected()
1191 {
1192     return g_list_find (parent->selected, this);
1193 }
1194
1195 /**
1196 \brief Deselect all stops/draggers (private)
1197 */
1198 void
1199 GrDrag::deselect_all()
1200 {
1201     while (selected) {
1202         ( (GrDragger*) selected->data)->deselect();
1203         selected = g_list_remove(selected, selected->data);
1204     }
1205 }
1206
1207 /**
1208 \brief Deselect all stops/draggers (public; emits signal)
1209 */
1210 void
1211 GrDrag::deselectAll()
1212 {
1213     deselect_all();
1214     this->desktop->emitToolSubselectionChanged(NULL);
1215 }
1216
1217 /**
1218 \brief Select all stops/draggers
1219 */
1220 void
1221 GrDrag::selectAll()
1222 {
1223     for (GList *l = this->draggers; l != NULL; l = l->next) {
1224         GrDragger *d = ((GrDragger *) l->data);
1225         setSelected (d, true, true);
1226     }
1227 }
1228
1229 /**
1230 \brief Select all stops/draggers that match the coords
1231 */
1232 void
1233 GrDrag::selectByCoords(std::vector<NR::Point> coords)
1234 {
1235     for (GList *l = this->draggers; l != NULL; l = l->next) {
1236         GrDragger *d = ((GrDragger *) l->data);
1237         for (guint k = 0; k < coords.size(); k++) {
1238             if (NR::L2 (d->point - coords[k]) < 1e-4) {
1239                 setSelected (d, true, true);
1240             }
1241         }
1242     }
1243 }
1244
1245 /**
1246 \brief Select a dragger
1247 \param dragger       The dragger to select
1248 \param add_to_selection   If true, add to selection, otherwise deselect others
1249 \param override      If true, always select this node, otherwise toggle selected status
1250 */
1251 void
1252 GrDrag::setSelected (GrDragger *dragger, bool add_to_selection, bool override)
1253 {
1254     GrDragger *seldragger = NULL;
1255
1256     if (add_to_selection) {
1257         if (!dragger) return;
1258         if (override) {
1259             if (!g_list_find(selected, dragger)) {
1260                 selected = g_list_prepend(selected, dragger);
1261             }
1262             dragger->select();
1263             seldragger = dragger;
1264         } else { // toggle
1265             if (g_list_find(selected, dragger)) {
1266                 selected = g_list_remove(selected, dragger);
1267                 dragger->deselect();
1268                 if (selected) {
1269                     seldragger = (GrDragger*) selected->data; // select the dragger that is first in the list
1270                 }
1271             } else {
1272                 selected = g_list_prepend(selected, dragger);
1273                 dragger->select();
1274                 seldragger = dragger;
1275             }
1276         }
1277     } else {
1278         deselect_all();
1279         if (dragger) {
1280             selected = g_list_prepend(selected, dragger);
1281             dragger->select();
1282             seldragger = dragger;
1283         }
1284     }
1285     if (seldragger) {
1286         this->desktop->emitToolSubselectionChanged((gpointer) seldragger);
1287     }
1288 }
1289
1290 /**
1291 \brief Deselect a dragger
1292 \param dragger       The dragger to deselect
1293 */
1294 void
1295 GrDrag::setDeselected (GrDragger *dragger)
1296 {
1297     if (g_list_find(selected, dragger)) {
1298         selected = g_list_remove(selected, dragger);
1299         dragger->deselect();
1300     }
1301     this->desktop->emitToolSubselectionChanged((gpointer) (selected ? selected->data : NULL ));
1302 }
1303
1304
1305
1306 /**
1307 Create a line from p1 to p2 and add it to the lines list
1308  */
1309 void
1310 GrDrag::addLine (NR::Point p1, NR::Point p2, guint32 rgba)
1311 {
1312     SPCanvasItem *line = sp_canvas_item_new(sp_desktop_controls(this->desktop),
1313                                                             SP_TYPE_CTRLLINE, NULL);
1314     sp_ctrlline_set_coords(SP_CTRLLINE(line), p1, p2);
1315     if (rgba != GR_LINE_COLOR_FILL) // fill is the default, so don't set color for it to speed up redraw
1316         sp_ctrlline_set_rgba32 (SP_CTRLLINE(line), rgba);
1317     sp_canvas_item_show (line);
1318     this->lines = g_slist_append (this->lines, line);
1319 }
1320
1321 /**
1322 If there already exists a dragger within MERGE_DIST of p, add the draggable to it; otherwise create
1323 new dragger and add it to draggers list
1324  */
1325 void
1326 GrDrag::addDragger (GrDraggable *draggable)
1327 {
1328     NR::Point p = sp_item_gradient_get_coords (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
1329
1330     for (GList *i = this->draggers; i != NULL; i = i->next) {
1331         GrDragger *dragger = (GrDragger *) i->data;
1332         if (dragger->mayMerge (draggable) && NR::L2 (dragger->point - p) < MERGE_DIST) {
1333             // distance is small, merge this draggable into dragger, no need to create new dragger
1334             dragger->addDraggable (draggable);
1335             dragger->updateKnotShape();
1336             return;
1337         }
1338     }
1339
1340     GrDragger *new_dragger = new GrDragger(this, p, draggable);
1341     // fixme: draggers should be added AFTER the last one: this way tabbing through them will be from begin to end.
1342     this->draggers = g_list_append (this->draggers, new_dragger);
1343 }
1344
1345 /**
1346 Add draggers for the radial gradient rg on item
1347 */
1348 void
1349 GrDrag::addDraggersRadial (SPRadialGradient *rg, SPItem *item, bool fill_or_stroke)
1350 {
1351     addDragger (new GrDraggable (item, POINT_RG_CENTER, 0, fill_or_stroke));
1352     guint num = rg->vector.stops.size();
1353     if (num > 2) {
1354         for ( guint i = 1; i < num - 1; i++ ) {
1355             addDragger (new GrDraggable (item, POINT_RG_MID1, i, fill_or_stroke));
1356         }
1357     }
1358     addDragger (new GrDraggable (item, POINT_RG_R1, num-1, fill_or_stroke));
1359     if (num > 2) {
1360         for ( guint i = 1; i < num - 1; i++ ) {
1361             addDragger (new GrDraggable (item, POINT_RG_MID2, i, fill_or_stroke));
1362         }
1363     }
1364     addDragger (new GrDraggable (item, POINT_RG_R2, num-1, fill_or_stroke));
1365     addDragger (new GrDraggable (item, POINT_RG_FOCUS, 0, fill_or_stroke));
1366 }
1367
1368 /**
1369 Add draggers for the linear gradient lg on item
1370 */
1371 void
1372 GrDrag::addDraggersLinear (SPLinearGradient *lg, SPItem *item, bool fill_or_stroke)
1373 {
1374     addDragger (new GrDraggable (item, POINT_LG_BEGIN, 0, fill_or_stroke));
1375     guint num = lg->vector.stops.size();
1376     if (num > 2) {
1377         for ( guint i = 1; i < num - 1; i++ ) {
1378             addDragger (new GrDraggable (item, POINT_LG_MID, i, fill_or_stroke));
1379         }
1380     }
1381     addDragger (new GrDraggable (item, POINT_LG_END, num-1, fill_or_stroke));
1382 }
1383
1384 /**
1385 Artificially grab the knot of the dragger with this draggable; used by the gradient context
1386 */
1387 void
1388 GrDrag::grabKnot (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, gint x, gint y, guint32 etime)
1389 {
1390     GrDragger *dragger = getDraggerFor (item, point_type, point_i, fill_or_stroke);
1391     if (dragger) {
1392         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1393     }
1394 }
1395
1396 /**
1397 Regenerates the draggers list from the current selection; is called when selection is changed or
1398 modified, also when a radial dragger needs to update positions of other draggers in the gradient
1399 */
1400 void
1401 GrDrag::updateDraggers ()
1402 {
1403     while (selected) {
1404         selected = g_list_remove(selected, selected->data);
1405     }
1406     // delete old draggers
1407     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1408         delete ((GrDragger *) i->data);
1409     }
1410     g_list_free (this->draggers);
1411     this->draggers = NULL;
1412
1413     g_return_if_fail (this->selection != NULL);
1414
1415     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1416
1417         SPItem *item = SP_ITEM(i->data);
1418         SPStyle *style = SP_OBJECT_STYLE (item);
1419
1420         if (style && (style->fill.isPaintserver())) {
1421             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1422             if (SP_IS_LINEARGRADIENT (server)) {
1423                 addDraggersLinear (SP_LINEARGRADIENT (server), item, true);
1424             } else if (SP_IS_RADIALGRADIENT (server)) {
1425                 addDraggersRadial (SP_RADIALGRADIENT (server), item, true);
1426             }
1427         }
1428
1429         if (style && (style->stroke.isPaintserver())) {
1430             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1431             if (SP_IS_LINEARGRADIENT (server)) {
1432                 addDraggersLinear (SP_LINEARGRADIENT (server), item, false);
1433             } else if (SP_IS_RADIALGRADIENT (server)) {
1434                 addDraggersRadial (SP_RADIALGRADIENT (server), item, false);
1435             }
1436         }
1437     }
1438 }
1439
1440 /**
1441 Regenerates the lines list from the current selection; is called on each move of a dragger, so that
1442 lines are always in sync with the actual gradient
1443 */
1444 void
1445 GrDrag::updateLines ()
1446 {
1447     // delete old lines
1448     for (GSList const *i = this->lines; i != NULL; i = i->next) {
1449         gtk_object_destroy( GTK_OBJECT (i->data));
1450     }
1451     g_slist_free (this->lines);
1452     this->lines = NULL;
1453
1454     g_return_if_fail (this->selection != NULL);
1455
1456     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1457
1458         SPItem *item = SP_ITEM(i->data);
1459
1460         SPStyle *style = SP_OBJECT_STYLE (item);
1461
1462         if (style && (style->fill.isPaintserver())) {
1463             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1464             if (SP_IS_LINEARGRADIENT (server)) {
1465                 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);
1466             } else if (SP_IS_RADIALGRADIENT (server)) {
1467                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, true);
1468                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, true), GR_LINE_COLOR_FILL);
1469                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, true), GR_LINE_COLOR_FILL);
1470             }
1471         }
1472
1473         if (style && (style->stroke.isPaintserver())) {
1474             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1475             if (SP_IS_LINEARGRADIENT (server)) {
1476                 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);
1477             } else if (SP_IS_RADIALGRADIENT (server)) {
1478                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, false);
1479                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, false), GR_LINE_COLOR_STROKE);
1480                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, false), GR_LINE_COLOR_STROKE);
1481             }
1482         }
1483     }
1484 }
1485
1486 /**
1487 Regenerates the levels list from the current selection
1488 */
1489 void
1490 GrDrag::updateLevels ()
1491 {
1492     hor_levels.clear();
1493     vert_levels.clear();
1494
1495     g_return_if_fail (this->selection != NULL);
1496
1497     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1498         SPItem *item = SP_ITEM(i->data);
1499         NR::Maybe<NR::Rect> rect = sp_item_bbox_desktop (item);
1500         if (rect) {
1501             // Remember the edges of the bbox and the center axis
1502             hor_levels.push_back(rect->min()[NR::Y]);
1503             hor_levels.push_back(rect->max()[NR::Y]);
1504             hor_levels.push_back(0.5 * (rect->min()[NR::Y] + rect->max()[NR::Y]));
1505             vert_levels.push_back(rect->min()[NR::X]);
1506             vert_levels.push_back(rect->max()[NR::X]);
1507             vert_levels.push_back(0.5 * (rect->min()[NR::X] + rect->max()[NR::X]));
1508         }
1509     }
1510 }
1511
1512 void
1513 GrDrag::selected_reverse_vector ()
1514 {
1515     if (selected == NULL)
1516         return;
1517
1518     for (GSList const* i = ( (GrDragger*) selected->data )->draggables; i != NULL; i = i->next) {
1519         GrDraggable *draggable = (GrDraggable *) i->data;
1520
1521         sp_item_gradient_reverse_vector (draggable->item, draggable->fill_or_stroke);
1522     }
1523 }
1524
1525 void
1526 GrDrag::selected_move_nowrite (double x, double y, bool scale_radial)
1527 {
1528     selected_move (x, y, false, scale_radial);
1529 }
1530
1531 void
1532 GrDrag::selected_move (double x, double y, bool write_repr, bool scale_radial)
1533 {
1534     if (selected == NULL)
1535         return;
1536
1537     bool did = false;
1538
1539     for (GList *i = selected; i != NULL; i = i->next) {
1540         GrDragger *d = (GrDragger *) i->data;
1541
1542         if (!d->isA(POINT_LG_MID) && !d->isA(POINT_RG_MID1) && !d->isA(POINT_RG_MID2)) {
1543             // if this is a an endpoint,
1544
1545             // Moving an rg center moves its focus and radii as well.
1546             // therefore, if this is a focus or radius and if selection
1547             // contains the center as well, do not move this one
1548             if (d->isA(POINT_RG_R1) || d->isA(POINT_RG_R2) ||
1549                 (d->isA(POINT_RG_FOCUS) && !d->isA(POINT_RG_CENTER))) {
1550                 bool skip_radius_with_center = false;
1551                 for (GList *di = selected; di != NULL; di = di->next) {
1552                     GrDragger *d_new = (GrDragger *) di->data;
1553                     if (d_new->isA (((GrDraggable *) d->draggables->data)->item,
1554                                     POINT_RG_CENTER,
1555                                     0,
1556                                     ((GrDraggable *) d->draggables->data)->fill_or_stroke)) {
1557                         // FIXME: here we take into account only the first draggable!
1558                         skip_radius_with_center = true;
1559                     }
1560                 }
1561                 if (skip_radius_with_center)
1562                     continue;
1563             }
1564
1565             did = true;
1566             d->point += NR::Point (x, y);
1567             d->point_original = d->point;
1568             sp_knot_moveto (d->knot, &(d->point));
1569
1570             d->fireDraggables (write_repr, scale_radial);
1571
1572             d->updateDependencies(write_repr);
1573         }
1574     }
1575
1576     if (!did) { // none of the end draggers are selected, so let's try to move the mids
1577         for (GList *i = selected; i != NULL; i = i->next) {
1578             GrDragger *d = (GrDragger *) i->data;
1579
1580             if (d->isA(POINT_LG_MID) || !d->isA(POINT_RG_MID1) || !d->isA(POINT_RG_MID2)) {
1581             }
1582         }
1583     }
1584
1585     if (write_repr && did) {
1586         // we did an undoable action
1587         sp_document_maybe_done (sp_desktop_document (desktop), "grmove", SP_VERB_CONTEXT_GRADIENT,
1588                           _("Move gradient handle"));
1589     }
1590 }
1591
1592 void
1593 GrDrag::selected_move_screen (double x, double y)
1594 {
1595     gdouble zoom = desktop->current_zoom();
1596     gdouble zx = x / zoom;
1597     gdouble zy = y / zoom;
1598
1599     selected_move (zx, zy);
1600 }
1601
1602 /**
1603 Select the knot next to the last selected one and deselect all other selected.
1604 */
1605 void
1606 GrDrag::select_next ()
1607 {
1608     if (selected == NULL || g_list_find(draggers, selected->data)->next == NULL) {
1609         if (draggers)
1610             setSelected ((GrDragger *) draggers->data);
1611     } else {
1612         setSelected ((GrDragger *) g_list_find(draggers, selected->data)->next->data);
1613     }
1614 }
1615
1616 /**
1617 Select the knot previous from the last selected one and deselect all other selected.
1618 */
1619 void
1620 GrDrag::select_prev ()
1621 {
1622     if (selected == NULL || g_list_find(draggers, selected->data)->prev == NULL) {
1623         if (draggers)
1624             setSelected ((GrDragger *) g_list_last (draggers)->data);
1625     } else {
1626         setSelected ((GrDragger *) g_list_find(draggers, selected->data)->prev->data);
1627     }
1628 }
1629
1630
1631 // FIXME: i.m.o. an ugly function that I just made to work, but... aargh! (Johan)
1632 void
1633 GrDrag::deleteSelected (bool just_one)
1634 {
1635     if (!selected) return;
1636
1637     SPDocument *document = false;
1638
1639     struct StructStopInfo {
1640         SPStop * spstop;
1641         GrDraggable * draggable;
1642         SPGradient * gradient;
1643         SPGradient * vector;
1644     };
1645
1646     GSList *midstoplist = NULL;  // list of stops that must be deleted (will be deleted first)
1647     GSList *endstoplist = NULL;  // list of stops that must be deleted
1648     while (selected) {
1649         GrDragger *dragger = (GrDragger*) selected->data;
1650         for (GSList * drgble = dragger->draggables; drgble != NULL; drgble = drgble->next) {
1651             GrDraggable *draggable = (GrDraggable*) drgble->data;
1652             SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
1653             SPGradient *vector   = sp_gradient_get_forked_vector_if_necessary (gradient, false);
1654
1655             switch (draggable->point_type) {
1656                 case POINT_LG_MID:
1657                 case POINT_RG_MID1:
1658                 case POINT_RG_MID2:
1659                     {
1660                         SPStop *stop = sp_get_stop_i(vector, draggable->point_i);
1661                         // check if already present in list. (e.g. when both RG_MID1 and RG_MID2 were selected)
1662                         bool present = false;
1663                         for (GSList const * l = midstoplist; l != NULL; l = l->next) {
1664                             if ( (SPStop*)l->data == stop ) {
1665                                 present = true;
1666                                 break; // no need to search further.
1667                             }
1668                         }
1669                         if (!present)
1670                             midstoplist = g_slist_append(midstoplist, stop);
1671                     }
1672                     break;
1673                 case POINT_LG_BEGIN:
1674                 case POINT_LG_END:
1675                 case POINT_RG_CENTER:
1676                 case POINT_RG_R1:
1677                 case POINT_RG_R2:
1678                     {
1679                         SPStop *stop = NULL;
1680                         if ( (draggable->point_type == POINT_LG_BEGIN) || (draggable->point_type == POINT_RG_CENTER) ) {
1681                             stop = sp_first_stop(vector);
1682                         } else {
1683                             stop = sp_last_stop(vector);
1684                         }
1685                         if (stop) {
1686                             StructStopInfo *stopinfo = new StructStopInfo;
1687                             stopinfo->spstop = stop;
1688                             stopinfo->draggable = draggable;
1689                             stopinfo->gradient = gradient;
1690                             stopinfo->vector = vector;
1691                             // check if already present in list. (e.g. when both R1 and R2 were selected)
1692                             bool present = false;
1693                             for (GSList const * l = endstoplist; l != NULL; l = l->next) {
1694                                 if ( ((StructStopInfo*)l->data)->spstop == stopinfo->spstop ) {
1695                                     present = true;
1696                                     break; // no need to search further.
1697                                 }
1698                             }
1699                             if (!present)
1700                                 endstoplist = g_slist_append(endstoplist, stopinfo);
1701                         }
1702                     }
1703                     break;
1704                 default:
1705                     break;
1706             }
1707         }
1708         selected = g_list_remove(selected, dragger);
1709         if ( just_one ) break; // iterate once if just_one is set.
1710     }
1711     while (midstoplist) {
1712         SPStop *stop = (SPStop*) midstoplist->data;
1713         document = SP_OBJECT_DOCUMENT (stop);
1714         Inkscape::XML::Node * parent = SP_OBJECT_REPR(stop)->parent();
1715         parent->removeChild(SP_OBJECT_REPR(stop));
1716         midstoplist = g_slist_remove(midstoplist, stop);
1717     }
1718     while (endstoplist) {
1719         StructStopInfo *stopinfo  = (StructStopInfo*) endstoplist->data;
1720         document = SP_OBJECT_DOCUMENT (stopinfo->spstop);
1721
1722         // 2 is the minimum, cannot delete more than that without deleting the whole vector
1723         // cannot use vector->vector.stops.size() because the vector might be invalidated by deletion of a midstop
1724         // manually count the children, don't know if there already exists a function for this...
1725         int len = 0;
1726         for ( SPObject *child = sp_object_first_child(stopinfo->vector) ;
1727               child != NULL ;
1728               child = SP_OBJECT_NEXT(child) )
1729         {
1730             if ( SP_IS_STOP(child) )  len ++;
1731         }
1732         if (len > 2)
1733         {
1734             switch (stopinfo->draggable->point_type) {
1735                 case POINT_LG_BEGIN:
1736                     {
1737                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1738
1739                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
1740                         NR::Point oldbegin = NR::Point (lg->x1.computed, lg->y1.computed);
1741                         NR::Point end = NR::Point (lg->x2.computed, lg->y2.computed);
1742                         SPStop *stop = sp_first_stop(stopinfo->vector);
1743                         gdouble offset = stop->offset;
1744                         NR::Point newbegin = oldbegin + offset * (end - oldbegin);
1745                         lg->x1.computed = newbegin[NR::X];
1746                         lg->y1.computed = newbegin[NR::Y];
1747
1748                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
1749                         sp_repr_set_svg_double(repr, "x1", lg->x1.computed);
1750                         sp_repr_set_svg_double(repr, "y1", lg->y1.computed);
1751                         stop->offset = 0;
1752                         sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", 0);
1753
1754                         // iterate through midstops to set new offset values such that they won't move on canvas.
1755                         SPStop *laststop = sp_last_stop(stopinfo->vector);
1756                         stop = sp_next_stop(stop);
1757                         while ( stop != laststop ) {
1758                             stop->offset = (stop->offset - offset)/(1 - offset);
1759                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
1760                             stop = sp_next_stop(stop);
1761                         }
1762                     }
1763                     break;
1764                 case POINT_LG_END:
1765                     {
1766                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1767
1768                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
1769                         NR::Point begin = NR::Point (lg->x1.computed, lg->y1.computed);
1770                         NR::Point oldend = NR::Point (lg->x2.computed, lg->y2.computed);
1771                         SPStop *laststop = sp_last_stop(stopinfo->vector);
1772                         gdouble offset = laststop->offset;
1773                         NR::Point newend = begin + offset * (oldend - begin);
1774                         lg->x2.computed = newend[NR::X];
1775                         lg->y2.computed = newend[NR::Y];
1776
1777                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
1778                         sp_repr_set_svg_double(repr, "x2", lg->x2.computed);
1779                         sp_repr_set_svg_double(repr, "y2", lg->y2.computed);
1780                         laststop->offset = 1;
1781                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
1782
1783                         // iterate through midstops to set new offset values such that they won't move on canvas.
1784                         SPStop *stop = sp_first_stop(stopinfo->vector);
1785                         stop = sp_next_stop(stop);
1786                         while ( stop != laststop ) {
1787                             stop->offset = stop->offset / offset;
1788                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
1789                             stop = sp_next_stop(stop);
1790                         }
1791                     }
1792                     break;
1793                 case POINT_RG_CENTER:
1794                     {
1795                         SPStop *newfirst = sp_next_stop (stopinfo->spstop);
1796                         if (newfirst) {
1797                             newfirst->offset = 0;
1798                             sp_repr_set_css_double (SP_OBJECT_REPR (newfirst), "offset", 0);
1799                         }
1800                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1801                     }
1802                     break;
1803                 case POINT_RG_R1:
1804                 case POINT_RG_R2:
1805                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1806
1807                         SPRadialGradient *rg = SP_RADIALGRADIENT(stopinfo->gradient);
1808                         double oldradius = rg->r.computed;
1809                         SPStop *laststop = sp_last_stop(stopinfo->vector);
1810                         gdouble offset = laststop->offset;
1811                         double newradius = offset * oldradius;
1812                         rg->r.computed = newradius;
1813
1814                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(rg);
1815                         sp_repr_set_svg_double(repr, "r", rg->r.computed);
1816                         laststop->offset = 1;
1817                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
1818
1819                         // iterate through midstops to set new offset values such that they won't move on canvas.
1820                         SPStop *stop = sp_first_stop(stopinfo->vector);
1821                         stop = sp_next_stop(stop);
1822                         while ( stop != laststop ) {
1823                             stop->offset = stop->offset / offset;
1824                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
1825                             stop = sp_next_stop(stop);
1826                         }
1827                         break;
1828             }
1829         }
1830         else
1831         { // delete the gradient from the object. set fill to unset  FIXME: set to fill of unselected node?
1832             SPCSSAttr *css = sp_repr_css_attr_new ();
1833
1834             // stopinfo->spstop is the selected stop
1835             Inkscape::XML::Node *unselectedrepr = SP_OBJECT_REPR(stopinfo->vector)->firstChild();
1836             if (unselectedrepr == SP_OBJECT_REPR(stopinfo->spstop) ) {
1837                 unselectedrepr = unselectedrepr->next();
1838             }
1839
1840             if (unselectedrepr == NULL) {
1841                 if (stopinfo->draggable->fill_or_stroke) {
1842                     sp_repr_css_unset_property (css, "fill");
1843                 } else {
1844                     sp_repr_css_unset_property (css, "stroke");
1845                 }
1846             } else {
1847                 SPCSSAttr *stopcss = sp_repr_css_attr(unselectedrepr, "style");
1848                 if (stopinfo->draggable->fill_or_stroke) {
1849                     sp_repr_css_set_property(css, "fill", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
1850                     sp_repr_css_set_property(css, "fill-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
1851                 } else {
1852                     sp_repr_css_set_property(css, "stroke", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
1853                     sp_repr_css_set_property(css, "stroke-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
1854                 }
1855                 sp_repr_css_attr_unref (stopcss);
1856             }
1857
1858             sp_repr_css_change (SP_OBJECT_REPR (stopinfo->draggable->item), css, "style");
1859             sp_repr_css_attr_unref (css);
1860         }
1861
1862         endstoplist = g_slist_remove(endstoplist, stopinfo);
1863         delete stopinfo;
1864     }
1865
1866     if (document) {
1867         sp_document_done ( document, SP_VERB_CONTEXT_GRADIENT, _("Delete gradient stop(s)") );
1868     }
1869 }
1870
1871
1872 /*
1873   Local Variables:
1874   mode:c++
1875   c-file-style:"stroustrup"
1876   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1877   indent-tabs-mode:nil
1878   fill-column:99
1879   End:
1880 */
1881 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :