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>mid stop</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_("Radial gradient <b>mid stop</b>"),
  82     N_("Radial gradient <b>mid stop</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 = dragger->isSelected();
 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         NR::Point this_move = displacement;
 662         if (state & GDK_MOD1_MASK) {
 663             // FIXME: unify all these profiles (here, in nodepath, in tweak) in one place
 664             double alpha = 1.5;
 665             if (NR::L2(drg->point - dragger->point) + NR::L2(drg->point - begin) - 1e-3 > NR::L2(dragger->point - begin)) { // drg is on the end side from dragger
 666                 double x = NR::L2(drg->point - dragger->point)/NR::L2(end - dragger->point);
 667                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 668             } else { // drg is on the begin side from dragger
 669                 double x = NR::L2(drg->point - dragger->point)/NR::L2(begin - dragger->point);
 670                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 671             }
 672         }
 673         drg->point += this_move;
 674         sp_knot_moveto (drgknot, & drg->point);
 675         drg->fireDraggables (false);
 676         drg->updateDependencies(false);
 677     }
 678
 679     g_slist_free(moving);
 680
 681     drag->keep_selection = is_selected;
 682 }
 683
 684
 685
 686 static void
 687 gr_knot_grabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 688 {
 689     GrDragger *dragger = (GrDragger *) data;
 690
 691     sp_canvas_force_full_redraw_after_interruptions(dragger->parent->desktop->canvas, 5);
 692 }
 693
 694 /**
 695 Called when the mouse releases a dragger knot; changes gradient writing to repr, updates other draggers if needed
 696 */
 697 static void
 698 gr_knot_ungrabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 699 {
 700     GrDragger *dragger = (GrDragger *) data;
 701
 702     sp_canvas_end_forced_full_redraws(dragger->parent->desktop->canvas);
 703
 704     dragger->point_original = dragger->point = knot->pos;
 705
 706     if ((state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK)) {
 707         dragger->fireDraggables (true, true);
 708     } else {
 709         dragger->fireDraggables (true);
 710     }
 711
 712     for (GList *i = dragger->parent->selected; i != NULL; i = i->next) {
 713         GrDragger *d = (GrDragger *) i->data;
 714         if (d == dragger)
 715             continue;
 716         d->fireDraggables (true);
 717     }
 718
 719     // make this dragger selected
 720     if (!dragger->parent->keep_selection) {
 721         dragger->parent->setSelected (dragger);
 722     }
 723     dragger->parent->keep_selection = false;
 724
 725     dragger->updateDependencies(true);
 726
 727     // we did an undoable action
 728     sp_document_done (sp_desktop_document (dragger->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 729                       _("Move gradient handle"));
 730 }
 731
 732 /**
 733 Called when a dragger knot is clicked; selects the dragger or deletes it depending on the
 734 state of the keyboard keys
 735 */
 736 static void
 737 gr_knot_clicked_handler(SPKnot *knot, guint state, gpointer data)
 738 {
 739     GrDragger *dragger = (GrDragger *) data;
 740     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 741     if (!draggable) return;
 742
 743     if ( (state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK ) ) {
 744     // delete this knot from vector
 745         SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
 746         gradient = sp_gradient_get_vector (gradient, false);
 747         if (gradient->vector.stops.size() > 2) { // 2 is the minimum
 748                 SPStop *stop = NULL;
 749                 switch (draggable->point_type) {  // if we delete first or last stop, move the next/previous to the edge
 750                 case POINT_LG_BEGIN:
 751                 case POINT_RG_CENTER:
 752                     stop = sp_first_stop(gradient);
 753                         {
 754                             SPStop *next = sp_next_stop (stop);
 755                                 if (next) {
 756                                         next->offset = 0;
 757                                         sp_repr_set_css_double (SP_OBJECT_REPR (next), "offset", 0);
 758                                 }
 759                         }
 760                     break;
 761                 case POINT_LG_END:
 762                 case POINT_RG_R1:
 763                 case POINT_RG_R2:
 764                     stop = sp_last_stop(gradient);
 765                     {
 766                             SPStop *prev = sp_prev_stop (stop, gradient);
 767                             if (prev) {
 768                                     prev->offset = 1;
 769                                     sp_repr_set_css_double (SP_OBJECT_REPR (prev), "offset", 1);
 770                             }
 771                         }
 772                     break;
 773                 case POINT_LG_MID:
 774                 case POINT_RG_MID1:
 775                 case POINT_RG_MID2:
 776                     stop = sp_get_stop_i(gradient, draggable->point_i);
 777                     break;
 778                 }
 779
 780                 SP_OBJECT_REPR(gradient)->removeChild(SP_OBJECT_REPR(stop));
 781                 sp_document_done (SP_OBJECT_DOCUMENT (gradient), SP_VERB_CONTEXT_GRADIENT,
 782                                   _("Delete gradient stop"));
 783         }
 784     } else {
 785     // select the dragger
 786         dragger->point_original = dragger->point;
 787
 788         if ( state & GDK_SHIFT_MASK ) {
 789             dragger->parent->setSelected (dragger, true, false);
 790         } else {
 791             dragger->parent->setSelected (dragger);
 792         }
 793     }
 794 }
 795
 796 /**
 797 Called when a dragger knot is doubleclicked; opens gradient editor with the stop from the first draggable
 798 */
 799 static void
 800 gr_knot_doubleclicked_handler (SPKnot *knot, guint state, gpointer data)
 801 {
 802     GrDragger *dragger = (GrDragger *) data;
 803
 804     dragger->point_original = dragger->point;
 805
 806     if (dragger->draggables == NULL)
 807         return;
 808
 809     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 810     sp_item_gradient_edit_stop (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 811 }
 812
 813 /**
 814 Act upon all draggables of the dragger, setting them to the dragger's point
 815 */
 816 void
 817 GrDragger::fireDraggables (bool write_repr, bool scale_radial, bool merging_focus)
 818 {
 819     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 820         GrDraggable *draggable = (GrDraggable *) i->data;
 821
 822         // set local_change flag so that selection_changed callback does not regenerate draggers
 823         this->parent->local_change = true;
 824
 825         // change gradient, optionally writing to repr; prevent focus from moving if it's snapped
 826         // to the center, unless it's the first update upon merge when we must snap it to the point
 827         if (merging_focus ||
 828             !(draggable->point_type == POINT_RG_FOCUS && this->isA(draggable->item, POINT_RG_CENTER, draggable->point_i, draggable->fill_or_stroke)))
 829         {
 830             sp_item_gradient_set_coords (draggable->item, draggable->point_type, draggable->point_i, this->point, draggable->fill_or_stroke, write_repr, scale_radial);
 831         }
 832     }
 833 }
 834
 835 /**
 836 Checks if the dragger has a draggable with this point_type
 837  */
 838 bool
 839 GrDragger::isA (gint point_type)
 840 {
 841     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 842         GrDraggable *draggable = (GrDraggable *) i->data;
 843         if (draggable->point_type == point_type) {
 844             return true;
 845         }
 846     }
 847     return false;
 848 }
 849
 850 /**
 851 Checks if the dragger has a draggable with this item, point_type, fill_or_stroke
 852  */
 853 bool
 854 GrDragger::isA (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
 855 {
 856     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 857         GrDraggable *draggable = (GrDraggable *) i->data;
 858         if ( (draggable->point_type == point_type) && (draggable->point_i == point_i) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
 859             return true;
 860         }
 861     }
 862     return false;
 863 }
 864
 865 bool
 866 GrDraggable::mayMerge (GrDraggable *da2)
 867 {
 868     if ((this->item == da2->item) && (this->fill_or_stroke == da2->fill_or_stroke)) {
 869         // we must not merge the points of the same gradient!
 870         if (!((this->point_type == POINT_RG_FOCUS && da2->point_type == POINT_RG_CENTER) ||
 871               (this->point_type == POINT_RG_CENTER && da2->point_type == POINT_RG_FOCUS))) {
 872             // except that we can snap center and focus together
 873             return false;
 874         }
 875     }
 876     // disable merging of midpoints.
 877     if ( (this->point_type == POINT_LG_MID) || (da2->point_type == POINT_LG_MID)
 878          || (this->point_type == POINT_RG_MID1) || (da2->point_type == POINT_RG_MID1)
 879          || (this->point_type == POINT_RG_MID2) || (da2->point_type == POINT_RG_MID2) )
 880         return false;
 881
 882     return true;
 883 }
 884
 885 bool
 886 GrDragger::mayMerge (GrDragger *other)
 887 {
 888     if (this == other)
 889         return false;
 890
 891     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
 892         GrDraggable *da1 = (GrDraggable *) i->data;
 893         for (GSList const* j = other->draggables; j != NULL; j = j->next) { // for all draggables of other
 894             GrDraggable *da2 = (GrDraggable *) j->data;
 895             if (!da1->mayMerge(da2))
 896                 return false;
 897         }
 898     }
 899     return true;
 900 }
 901
 902 bool
 903 GrDragger::mayMerge (GrDraggable *da2)
 904 {
 905     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
 906         GrDraggable *da1 = (GrDraggable *) i->data;
 907         if (!da1->mayMerge(da2))
 908             return false;
 909     }
 910     return true;
 911 }
 912
 913 /**
 914 Updates the statusbar tip of the dragger knot, based on its draggables
 915  */
 916 void
 917 GrDragger::updateTip ()
 918 {
 919         if (this->knot && this->knot->tip) {
 920                 g_free (this->knot->tip);
 921                 this->knot->tip = NULL;
 922         }
 923
 924     if (g_slist_length (this->draggables) == 1) {
 925         GrDraggable *draggable = (GrDraggable *) this->draggables->data;
 926         char *item_desc = sp_item_description(draggable->item);
 927         switch (draggable->point_type) {
 928             case POINT_LG_MID:
 929             case POINT_RG_MID1:
 930             case POINT_RG_MID2:
 931                 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"),
 932                                                    _(gr_knot_descr[draggable->point_type]),
 933                                                    draggable->point_i,
 934                                                    item_desc,
 935                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
 936                 break;
 937
 938             default:
 939                 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"),
 940                                                    _(gr_knot_descr[draggable->point_type]),
 941                                                    item_desc,
 942                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
 943                 break;
 944         }
 945         g_free(item_desc);
 946     } else if (g_slist_length (draggables) == 2 && isA (POINT_RG_CENTER) && isA (POINT_RG_FOCUS)) {
 947         this->knot->tip = g_strdup_printf (_("Radial gradient <b>center</b> and <b>focus</b>; drag with <b>Shift</b> to separate focus"));
 948     } else {
 949         int length = g_slist_length (this->draggables);
 950         this->knot->tip = g_strdup_printf (ngettext("Gradient point shared by <b>%d</b> gradient; drag with <b>Shift</b> to separate",
 951                                                     "Gradient point shared by <b>%d</b> gradients; drag with <b>Shift</b> to separate",
 952                                                     length),
 953                                            length);
 954     }
 955 }
 956
 957 /**
 958 Adds a draggable to the dragger
 959  */
 960 void
 961 GrDragger::updateKnotShape ()
 962 {
 963     if (!draggables)
 964         return;
 965     GrDraggable *last = (GrDraggable *) g_slist_last(draggables)->data;
 966     g_object_set (G_OBJECT (this->knot->item), "shape", gr_knot_shapes[last->point_type], NULL);
 967 }
 968
 969 /**
 970 Adds a draggable to the dragger
 971  */
 972 void
 973 GrDragger::addDraggable (GrDraggable *draggable)
 974 {
 975     this->draggables = g_slist_prepend (this->draggables, draggable);
 976
 977     this->updateTip();
 978 }
 979
 980
 981 /**
 982 Moves this dragger to the point of the given draggable, acting upon all other draggables
 983  */
 984 void
 985 GrDragger::moveThisToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
 986 {
 987     this->point = sp_item_gradient_get_coords (item, point_type, point_i, fill_or_stroke);
 988     this->point_original = this->point;
 989
 990     sp_knot_moveto (this->knot, &(this->point));
 991
 992     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 993         GrDraggable *da = (GrDraggable *) i->data;
 994         if ( (da->item == item) &&
 995              (point_type == -1 || da->point_type == point_type) &&
 996              (point_i == -1 || da->point_i == point_i) &&
 997              (da->fill_or_stroke == fill_or_stroke) ) {
 998             continue;
 999         }
1000         sp_item_gradient_set_coords (da->item, da->point_type, da->point_i, this->point, da->fill_or_stroke, write_repr, false);
1001     }
1002     // FIXME: here we should also call this->updateDependencies(write_repr); to propagate updating, but how to prevent loops?
1003 }
1004
1005
1006 /**
1007 Moves all midstop draggables that depend on this one
1008  */
1009 void
1010 GrDragger::updateMidstopDependencies (GrDraggable *draggable, bool write_repr) {
1011     SPObject *server;
1012     if (draggable->fill_or_stroke)
1013         server = SP_OBJECT_STYLE_FILL_SERVER (draggable->item);
1014     else
1015         server = SP_OBJECT_STYLE_STROKE_SERVER (draggable->item);
1016     guint num = SP_GRADIENT(server)->vector.stops.size();
1017     if (num <= 2) return;
1018
1019     if ( SP_IS_LINEARGRADIENT(server) ) {
1020         for ( guint i = 1; i < num - 1; i++ ) {
1021             this->moveOtherToDraggable (draggable->item, POINT_LG_MID, i, draggable->fill_or_stroke, write_repr);
1022         }
1023     } else  if ( SP_IS_RADIALGRADIENT(server) ) {
1024         for ( guint i = 1; i < num - 1; i++ ) {
1025             this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, i, draggable->fill_or_stroke, write_repr);
1026             this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, i, draggable->fill_or_stroke, write_repr);
1027         }
1028     }
1029 }
1030
1031
1032 /**
1033 Moves all draggables that depend on this one
1034  */
1035 void
1036 GrDragger::updateDependencies (bool write_repr)
1037 {
1038     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1039         GrDraggable *draggable = (GrDraggable *) i->data;
1040         switch (draggable->point_type) {
1041             case POINT_LG_BEGIN:
1042                 {
1043                     // the end point is dependent only when dragging with ctrl+shift
1044                     this->moveOtherToDraggable (draggable->item, POINT_LG_END, -1, draggable->fill_or_stroke, write_repr);
1045
1046                     this->updateMidstopDependencies (draggable, write_repr);
1047                 }
1048                 break;
1049             case POINT_LG_END:
1050                 {
1051                     // the begin point is dependent only when dragging with ctrl+shift
1052                     this->moveOtherToDraggable (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke, write_repr);
1053
1054                     this->updateMidstopDependencies (draggable, write_repr);
1055                 }
1056                 break;
1057             case POINT_LG_MID:
1058                 // no other nodes depend on mid points.
1059                 break;
1060             case POINT_RG_R2:
1061                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1062                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1063                 this->updateMidstopDependencies (draggable, write_repr);
1064                 break;
1065             case POINT_RG_R1:
1066                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1067                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1068                 this->updateMidstopDependencies (draggable, write_repr);
1069                 break;
1070             case POINT_RG_CENTER:
1071                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1072                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1073                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1074                 this->updateMidstopDependencies (draggable, write_repr);
1075                 break;
1076             case POINT_RG_FOCUS:
1077                 // nothing can depend on that
1078                 break;
1079             case POINT_RG_MID1:
1080                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, draggable->point_i, draggable->fill_or_stroke, write_repr);
1081                 break;
1082             case POINT_RG_MID2:
1083                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, draggable->point_i, draggable->fill_or_stroke, write_repr);
1084                 break;
1085             default:
1086                 break;
1087         }
1088     }
1089 }
1090
1091
1092
1093 GrDragger::GrDragger (GrDrag *parent, NR::Point p, GrDraggable *draggable)
1094 {
1095     this->draggables = NULL;
1096
1097     this->parent = parent;
1098
1099     this->point = p;
1100     this->point_original = p;
1101
1102     // create the knot
1103     this->knot = sp_knot_new (parent->desktop, NULL);
1104     this->knot->setMode(SP_KNOT_MODE_XOR);
1105     this->knot->setFill(GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_NORMAL);
1106     this->knot->setStroke(0x000000ff, 0x000000ff, 0x000000ff);
1107     sp_knot_update_ctrl(this->knot);
1108
1109     // move knot to the given point
1110     sp_knot_set_position (this->knot, &p, SP_KNOT_STATE_NORMAL);
1111     sp_knot_show (this->knot);
1112
1113     // connect knot's signals
1114     if ( (draggable)  // it can be NULL if a node in unsnapped (eg. focus point unsnapped from center)
1115                        // luckily, midstops never snap to other nodes so are never unsnapped...
1116          && ( (draggable->point_type == POINT_LG_MID)
1117               || (draggable->point_type == POINT_RG_MID1)
1118               || (draggable->point_type == POINT_RG_MID2) ) )
1119     {
1120         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_midpoint_handler), this);
1121     } else {
1122         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_handler), this);
1123     }
1124     g_signal_connect (G_OBJECT (this->knot), "clicked", G_CALLBACK (gr_knot_clicked_handler), this);
1125     g_signal_connect (G_OBJECT (this->knot), "doubleclicked", G_CALLBACK (gr_knot_doubleclicked_handler), this);
1126     g_signal_connect (G_OBJECT (this->knot), "grabbed", G_CALLBACK (gr_knot_grabbed_handler), this);
1127     g_signal_connect (G_OBJECT (this->knot), "ungrabbed", G_CALLBACK (gr_knot_ungrabbed_handler), this);
1128
1129     // add the initial draggable
1130     if (draggable)
1131         this->addDraggable (draggable);
1132     updateKnotShape();
1133 }
1134
1135 GrDragger::~GrDragger ()
1136 {
1137     // unselect if it was selected
1138     this->parent->setDeselected(this);
1139
1140     // disconnect signals
1141     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_moved_handler), this);
1142     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_clicked_handler), this);
1143     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_doubleclicked_handler), this);
1144     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_grabbed_handler), this);
1145     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_ungrabbed_handler), this);
1146
1147     /* unref should call destroy */
1148     g_object_unref (G_OBJECT (this->knot));
1149
1150     // delete all draggables
1151     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1152         delete ((GrDraggable *) i->data);
1153     }
1154     g_slist_free (this->draggables);
1155     this->draggables = NULL;
1156 }
1157
1158 /**
1159 Select the dragger which has the given draggable.
1160 */
1161 GrDragger *
1162 GrDrag::getDraggerFor (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1163 {
1164     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1165         GrDragger *dragger = (GrDragger *) i->data;
1166         for (GSList const* j = dragger->draggables; j != NULL; j = j->next) {
1167             GrDraggable *da2 = (GrDraggable *) j->data;
1168             if ( (da2->item == item) &&
1169                  (point_type == -1 || da2->point_type == point_type) && // -1 means this does not matter
1170                  (point_i == -1 || da2->point_i == point_i) && // -1 means this does not matter
1171                  (da2->fill_or_stroke == fill_or_stroke)) {
1172                 return (dragger);
1173             }
1174         }
1175     }
1176     return NULL;
1177 }
1178
1179
1180 void
1181 GrDragger::moveOtherToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1182 {
1183     GrDragger *d = this->parent->getDraggerFor (item, point_type, point_i, fill_or_stroke);
1184     if (d && d !=  this) {
1185         d->moveThisToDraggable (item, point_type, point_i, fill_or_stroke, write_repr);
1186     }
1187 }
1188
1189
1190 /**
1191   Draw this dragger as selected
1192 */
1193 void
1194 GrDragger::select()
1195 {
1196     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_SELECTED;
1197     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_SELECTED, NULL);
1198 }
1199
1200 /**
1201   Draw this dragger as normal (deselected)
1202 */
1203 void
1204 GrDragger::deselect()
1205 {
1206     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_NORMAL;
1207     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_NORMAL, NULL);
1208 }
1209
1210 bool
1211 GrDragger::isSelected()
1212 {
1213     return g_list_find (parent->selected, this);
1214 }
1215
1216 /**
1217 \brief Deselect all stops/draggers (private)
1218 */
1219 void
1220 GrDrag::deselect_all()
1221 {
1222     while (selected) {
1223         ( (GrDragger*) selected->data)->deselect();
1224         selected = g_list_remove(selected, selected->data);
1225     }
1226 }
1227
1228 /**
1229 \brief Deselect all stops/draggers (public; emits signal)
1230 */
1231 void
1232 GrDrag::deselectAll()
1233 {
1234     deselect_all();
1235     this->desktop->emitToolSubselectionChanged(NULL);
1236 }
1237
1238 /**
1239 \brief Select all stops/draggers
1240 */
1241 void
1242 GrDrag::selectAll()
1243 {
1244     for (GList *l = this->draggers; l != NULL; l = l->next) {
1245         GrDragger *d = ((GrDragger *) l->data);
1246         setSelected (d, true, true);
1247     }
1248 }
1249
1250 /**
1251 \brief Select all stops/draggers that match the coords
1252 */
1253 void
1254 GrDrag::selectByCoords(std::vector<NR::Point> coords)
1255 {
1256     for (GList *l = this->draggers; l != NULL; l = l->next) {
1257         GrDragger *d = ((GrDragger *) l->data);
1258         for (guint k = 0; k < coords.size(); k++) {
1259             if (NR::L2 (d->point - coords[k]) < 1e-4) {
1260                 setSelected (d, true, true);
1261             }
1262         }
1263     }
1264 }
1265
1266 /**
1267 \brief Select a dragger
1268 \param dragger       The dragger to select
1269 \param add_to_selection   If true, add to selection, otherwise deselect others
1270 \param override      If true, always select this node, otherwise toggle selected status
1271 */
1272 void
1273 GrDrag::setSelected (GrDragger *dragger, bool add_to_selection, bool override)
1274 {
1275     GrDragger *seldragger = NULL;
1276
1277     if (add_to_selection) {
1278         if (!dragger) return;
1279         if (override) {
1280             if (!g_list_find(selected, dragger)) {
1281                 selected = g_list_prepend(selected, dragger);
1282             }
1283             dragger->select();
1284             seldragger = dragger;
1285         } else { // toggle
1286             if (g_list_find(selected, dragger)) {
1287                 selected = g_list_remove(selected, dragger);
1288                 dragger->deselect();
1289                 if (selected) {
1290                     seldragger = (GrDragger*) selected->data; // select the dragger that is first in the list
1291                 }
1292             } else {
1293                 selected = g_list_prepend(selected, dragger);
1294                 dragger->select();
1295                 seldragger = dragger;
1296             }
1297         }
1298     } else {
1299         deselect_all();
1300         if (dragger) {
1301             selected = g_list_prepend(selected, dragger);
1302             dragger->select();
1303             seldragger = dragger;
1304         }
1305     }
1306     if (seldragger) {
1307         this->desktop->emitToolSubselectionChanged((gpointer) seldragger);
1308     }
1309 }
1310
1311 /**
1312 \brief Deselect a dragger
1313 \param dragger       The dragger to deselect
1314 */
1315 void
1316 GrDrag::setDeselected (GrDragger *dragger)
1317 {
1318     if (g_list_find(selected, dragger)) {
1319         selected = g_list_remove(selected, dragger);
1320         dragger->deselect();
1321     }
1322     this->desktop->emitToolSubselectionChanged((gpointer) (selected ? selected->data : NULL ));
1323 }
1324
1325
1326
1327 /**
1328 Create a line from p1 to p2 and add it to the lines list
1329  */
1330 void
1331 GrDrag::addLine (NR::Point p1, NR::Point p2, guint32 rgba)
1332 {
1333     SPCanvasItem *line = sp_canvas_item_new(sp_desktop_controls(this->desktop),
1334                                                             SP_TYPE_CTRLLINE, NULL);
1335     sp_ctrlline_set_coords(SP_CTRLLINE(line), p1, p2);
1336     if (rgba != GR_LINE_COLOR_FILL) // fill is the default, so don't set color for it to speed up redraw
1337         sp_ctrlline_set_rgba32 (SP_CTRLLINE(line), rgba);
1338     sp_canvas_item_show (line);
1339     this->lines = g_slist_append (this->lines, line);
1340 }
1341
1342 /**
1343 If there already exists a dragger within MERGE_DIST of p, add the draggable to it; otherwise create
1344 new dragger and add it to draggers list
1345  */
1346 void
1347 GrDrag::addDragger (GrDraggable *draggable)
1348 {
1349     NR::Point p = sp_item_gradient_get_coords (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
1350
1351     for (GList *i = this->draggers; i != NULL; i = i->next) {
1352         GrDragger *dragger = (GrDragger *) i->data;
1353         if (dragger->mayMerge (draggable) && NR::L2 (dragger->point - p) < MERGE_DIST) {
1354             // distance is small, merge this draggable into dragger, no need to create new dragger
1355             dragger->addDraggable (draggable);
1356             dragger->updateKnotShape();
1357             return;
1358         }
1359     }
1360
1361     GrDragger *new_dragger = new GrDragger(this, p, draggable);
1362     // fixme: draggers should be added AFTER the last one: this way tabbing through them will be from begin to end.
1363     this->draggers = g_list_append (this->draggers, new_dragger);
1364 }
1365
1366 /**
1367 Add draggers for the radial gradient rg on item
1368 */
1369 void
1370 GrDrag::addDraggersRadial (SPRadialGradient *rg, SPItem *item, bool fill_or_stroke)
1371 {
1372     addDragger (new GrDraggable (item, POINT_RG_CENTER, 0, fill_or_stroke));
1373     guint num = rg->vector.stops.size();
1374     if (num > 2) {
1375         for ( guint i = 1; i < num - 1; i++ ) {
1376             addDragger (new GrDraggable (item, POINT_RG_MID1, i, fill_or_stroke));
1377         }
1378     }
1379     addDragger (new GrDraggable (item, POINT_RG_R1, num-1, fill_or_stroke));
1380     if (num > 2) {
1381         for ( guint i = 1; i < num - 1; i++ ) {
1382             addDragger (new GrDraggable (item, POINT_RG_MID2, i, fill_or_stroke));
1383         }
1384     }
1385     addDragger (new GrDraggable (item, POINT_RG_R2, num-1, fill_or_stroke));
1386     addDragger (new GrDraggable (item, POINT_RG_FOCUS, 0, fill_or_stroke));
1387 }
1388
1389 /**
1390 Add draggers for the linear gradient lg on item
1391 */
1392 void
1393 GrDrag::addDraggersLinear (SPLinearGradient *lg, SPItem *item, bool fill_or_stroke)
1394 {
1395     addDragger (new GrDraggable (item, POINT_LG_BEGIN, 0, fill_or_stroke));
1396     guint num = lg->vector.stops.size();
1397     if (num > 2) {
1398         for ( guint i = 1; i < num - 1; i++ ) {
1399             addDragger (new GrDraggable (item, POINT_LG_MID, i, fill_or_stroke));
1400         }
1401     }
1402     addDragger (new GrDraggable (item, POINT_LG_END, num-1, fill_or_stroke));
1403 }
1404
1405 /**
1406 Artificially grab the knot of the dragger with this draggable; used by the gradient context
1407 */
1408 void
1409 GrDrag::grabKnot (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, gint x, gint y, guint32 etime)
1410 {
1411     GrDragger *dragger = getDraggerFor (item, point_type, point_i, fill_or_stroke);
1412     if (dragger) {
1413         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1414     }
1415 }
1416
1417 /**
1418 Regenerates the draggers list from the current selection; is called when selection is changed or
1419 modified, also when a radial dragger needs to update positions of other draggers in the gradient
1420 */
1421 void
1422 GrDrag::updateDraggers ()
1423 {
1424     while (selected) {
1425         selected = g_list_remove(selected, selected->data);
1426     }
1427     // delete old draggers
1428     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1429         delete ((GrDragger *) i->data);
1430     }
1431     g_list_free (this->draggers);
1432     this->draggers = NULL;
1433
1434     g_return_if_fail (this->selection != NULL);
1435
1436     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1437
1438         SPItem *item = SP_ITEM(i->data);
1439         SPStyle *style = SP_OBJECT_STYLE (item);
1440
1441         if (style && (style->fill.isPaintserver())) {
1442             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1443             if (SP_IS_LINEARGRADIENT (server)) {
1444                 addDraggersLinear (SP_LINEARGRADIENT (server), item, true);
1445             } else if (SP_IS_RADIALGRADIENT (server)) {
1446                 addDraggersRadial (SP_RADIALGRADIENT (server), item, true);
1447             }
1448         }
1449
1450         if (style && (style->stroke.isPaintserver())) {
1451             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1452             if (SP_IS_LINEARGRADIENT (server)) {
1453                 addDraggersLinear (SP_LINEARGRADIENT (server), item, false);
1454             } else if (SP_IS_RADIALGRADIENT (server)) {
1455                 addDraggersRadial (SP_RADIALGRADIENT (server), item, false);
1456             }
1457         }
1458     }
1459 }
1460
1461 /**
1462 Regenerates the lines list from the current selection; is called on each move of a dragger, so that
1463 lines are always in sync with the actual gradient
1464 */
1465 void
1466 GrDrag::updateLines ()
1467 {
1468     // delete old lines
1469     for (GSList const *i = this->lines; i != NULL; i = i->next) {
1470         gtk_object_destroy( GTK_OBJECT (i->data));
1471     }
1472     g_slist_free (this->lines);
1473     this->lines = NULL;
1474
1475     g_return_if_fail (this->selection != NULL);
1476
1477     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1478
1479         SPItem *item = SP_ITEM(i->data);
1480
1481         SPStyle *style = SP_OBJECT_STYLE (item);
1482
1483         if (style && (style->fill.isPaintserver())) {
1484             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1485             if (SP_IS_LINEARGRADIENT (server)) {
1486                 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);
1487             } else if (SP_IS_RADIALGRADIENT (server)) {
1488                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, true);
1489                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, true), GR_LINE_COLOR_FILL);
1490                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, true), GR_LINE_COLOR_FILL);
1491             }
1492         }
1493
1494         if (style && (style->stroke.isPaintserver())) {
1495             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1496             if (SP_IS_LINEARGRADIENT (server)) {
1497                 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);
1498             } else if (SP_IS_RADIALGRADIENT (server)) {
1499                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, false);
1500                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, false), GR_LINE_COLOR_STROKE);
1501                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, false), GR_LINE_COLOR_STROKE);
1502             }
1503         }
1504     }
1505 }
1506
1507 /**
1508 Regenerates the levels list from the current selection
1509 */
1510 void
1511 GrDrag::updateLevels ()
1512 {
1513     hor_levels.clear();
1514     vert_levels.clear();
1515
1516     g_return_if_fail (this->selection != NULL);
1517
1518     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1519         SPItem *item = SP_ITEM(i->data);
1520         NR::Maybe<NR::Rect> rect = sp_item_bbox_desktop (item);
1521         if (rect) {
1522             // Remember the edges of the bbox and the center axis
1523             hor_levels.push_back(rect->min()[NR::Y]);
1524             hor_levels.push_back(rect->max()[NR::Y]);
1525             hor_levels.push_back(0.5 * (rect->min()[NR::Y] + rect->max()[NR::Y]));
1526             vert_levels.push_back(rect->min()[NR::X]);
1527             vert_levels.push_back(rect->max()[NR::X]);
1528             vert_levels.push_back(0.5 * (rect->min()[NR::X] + rect->max()[NR::X]));
1529         }
1530     }
1531 }
1532
1533 void
1534 GrDrag::selected_reverse_vector ()
1535 {
1536     if (selected == NULL)
1537         return;
1538
1539     for (GSList const* i = ( (GrDragger*) selected->data )->draggables; i != NULL; i = i->next) {
1540         GrDraggable *draggable = (GrDraggable *) i->data;
1541
1542         sp_item_gradient_reverse_vector (draggable->item, draggable->fill_or_stroke);
1543     }
1544 }
1545
1546 void
1547 GrDrag::selected_move_nowrite (double x, double y, bool scale_radial)
1548 {
1549     selected_move (x, y, false, scale_radial);
1550 }
1551
1552 void
1553 GrDrag::selected_move (double x, double y, bool write_repr, bool scale_radial)
1554 {
1555     if (selected == NULL)
1556         return;
1557
1558     bool did = false;
1559
1560     for (GList *i = selected; i != NULL; i = i->next) {
1561         GrDragger *d = (GrDragger *) i->data;
1562
1563         if (!d->isA(POINT_LG_MID) && !d->isA(POINT_RG_MID1) && !d->isA(POINT_RG_MID2)) {
1564             // if this is a an endpoint,
1565
1566             // Moving an rg center moves its focus and radii as well.
1567             // therefore, if this is a focus or radius and if selection
1568             // contains the center as well, do not move this one
1569             if (d->isA(POINT_RG_R1) || d->isA(POINT_RG_R2) ||
1570                 (d->isA(POINT_RG_FOCUS) && !d->isA(POINT_RG_CENTER))) {
1571                 bool skip_radius_with_center = false;
1572                 for (GList *di = selected; di != NULL; di = di->next) {
1573                     GrDragger *d_new = (GrDragger *) di->data;
1574                     if (d_new->isA (((GrDraggable *) d->draggables->data)->item,
1575                                     POINT_RG_CENTER,
1576                                     0,
1577                                     ((GrDraggable *) d->draggables->data)->fill_or_stroke)) {
1578                         // FIXME: here we take into account only the first draggable!
1579                         skip_radius_with_center = true;
1580                     }
1581                 }
1582                 if (skip_radius_with_center)
1583                     continue;
1584             }
1585
1586             did = true;
1587             d->point += NR::Point (x, y);
1588             d->point_original = d->point;
1589             sp_knot_moveto (d->knot, &(d->point));
1590
1591             d->fireDraggables (write_repr, scale_radial);
1592
1593             d->updateDependencies(write_repr);
1594         }
1595     }
1596
1597     if (!did) { // none of the end draggers are selected, so let's try to move the mids
1598         for (GList *i = selected; i != NULL; i = i->next) {
1599             GrDragger *d = (GrDragger *) i->data;
1600
1601             if (d->isA(POINT_LG_MID) || !d->isA(POINT_RG_MID1) || !d->isA(POINT_RG_MID2)) {
1602             }
1603         }
1604     }
1605
1606     if (write_repr && did) {
1607         // we did an undoable action
1608         sp_document_maybe_done (sp_desktop_document (desktop), "grmove", SP_VERB_CONTEXT_GRADIENT,
1609                           _("Move gradient handle"));
1610     }
1611 }
1612
1613 void
1614 GrDrag::selected_move_screen (double x, double y)
1615 {
1616     gdouble zoom = desktop->current_zoom();
1617     gdouble zx = x / zoom;
1618     gdouble zy = y / zoom;
1619
1620     selected_move (zx, zy);
1621 }
1622
1623 /**
1624 Select the knot next to the last selected one and deselect all other selected.
1625 */
1626 void
1627 GrDrag::select_next ()
1628 {
1629     if (selected == NULL || g_list_find(draggers, selected->data)->next == NULL) {
1630         if (draggers)
1631             setSelected ((GrDragger *) draggers->data);
1632     } else {
1633         setSelected ((GrDragger *) g_list_find(draggers, selected->data)->next->data);
1634     }
1635 }
1636
1637 /**
1638 Select the knot previous from the last selected one and deselect all other selected.
1639 */
1640 void
1641 GrDrag::select_prev ()
1642 {
1643     if (selected == NULL || g_list_find(draggers, selected->data)->prev == NULL) {
1644         if (draggers)
1645             setSelected ((GrDragger *) g_list_last (draggers)->data);
1646     } else {
1647         setSelected ((GrDragger *) g_list_find(draggers, selected->data)->prev->data);
1648     }
1649 }
1650
1651
1652 // FIXME: i.m.o. an ugly function that I just made to work, but... aargh! (Johan)
1653 void
1654 GrDrag::deleteSelected (bool just_one)
1655 {
1656     if (!selected) return;
1657
1658     SPDocument *document = false;
1659
1660     struct StructStopInfo {
1661         SPStop * spstop;
1662         GrDraggable * draggable;
1663         SPGradient * gradient;
1664         SPGradient * vector;
1665     };
1666
1667     GSList *midstoplist = NULL;  // list of stops that must be deleted (will be deleted first)
1668     GSList *endstoplist = NULL;  // list of stops that must be deleted
1669     while (selected) {
1670         GrDragger *dragger = (GrDragger*) selected->data;
1671         for (GSList * drgble = dragger->draggables; drgble != NULL; drgble = drgble->next) {
1672             GrDraggable *draggable = (GrDraggable*) drgble->data;
1673             SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
1674             SPGradient *vector   = sp_gradient_get_forked_vector_if_necessary (gradient, false);
1675
1676             switch (draggable->point_type) {
1677                 case POINT_LG_MID:
1678                 case POINT_RG_MID1:
1679                 case POINT_RG_MID2:
1680                     {
1681                         SPStop *stop = sp_get_stop_i(vector, draggable->point_i);
1682                         // check if already present in list. (e.g. when both RG_MID1 and RG_MID2 were selected)
1683                         bool present = false;
1684                         for (GSList const * l = midstoplist; l != NULL; l = l->next) {
1685                             if ( (SPStop*)l->data == stop ) {
1686                                 present = true;
1687                                 break; // no need to search further.
1688                             }
1689                         }
1690                         if (!present)
1691                             midstoplist = g_slist_append(midstoplist, stop);
1692                     }
1693                     break;
1694                 case POINT_LG_BEGIN:
1695                 case POINT_LG_END:
1696                 case POINT_RG_CENTER:
1697                 case POINT_RG_R1:
1698                 case POINT_RG_R2:
1699                     {
1700                         SPStop *stop = NULL;
1701                         if ( (draggable->point_type == POINT_LG_BEGIN) || (draggable->point_type == POINT_RG_CENTER) ) {
1702                             stop = sp_first_stop(vector);
1703                         } else {
1704                             stop = sp_last_stop(vector);
1705                         }
1706                         if (stop) {
1707                             StructStopInfo *stopinfo = new StructStopInfo;
1708                             stopinfo->spstop = stop;
1709                             stopinfo->draggable = draggable;
1710                             stopinfo->gradient = gradient;
1711                             stopinfo->vector = vector;
1712                             // check if already present in list. (e.g. when both R1 and R2 were selected)
1713                             bool present = false;
1714                             for (GSList const * l = endstoplist; l != NULL; l = l->next) {
1715                                 if ( ((StructStopInfo*)l->data)->spstop == stopinfo->spstop ) {
1716                                     present = true;
1717                                     break; // no need to search further.
1718                                 }
1719                             }
1720                             if (!present)
1721                                 endstoplist = g_slist_append(endstoplist, stopinfo);
1722                         }
1723                     }
1724                     break;
1725                 default:
1726                     break;
1727             }
1728         }
1729         selected = g_list_remove(selected, dragger);
1730         if ( just_one ) break; // iterate once if just_one is set.
1731     }
1732     while (midstoplist) {
1733         SPStop *stop = (SPStop*) midstoplist->data;
1734         document = SP_OBJECT_DOCUMENT (stop);
1735         Inkscape::XML::Node * parent = SP_OBJECT_REPR(stop)->parent();
1736         parent->removeChild(SP_OBJECT_REPR(stop));
1737         midstoplist = g_slist_remove(midstoplist, stop);
1738     }
1739     while (endstoplist) {
1740         StructStopInfo *stopinfo  = (StructStopInfo*) endstoplist->data;
1741         document = SP_OBJECT_DOCUMENT (stopinfo->spstop);
1742
1743         // 2 is the minimum, cannot delete more than that without deleting the whole vector
1744         // cannot use vector->vector.stops.size() because the vector might be invalidated by deletion of a midstop
1745         // manually count the children, don't know if there already exists a function for this...
1746         int len = 0;
1747         for ( SPObject *child = sp_object_first_child(stopinfo->vector) ;
1748               child != NULL ;
1749               child = SP_OBJECT_NEXT(child) )
1750         {
1751             if ( SP_IS_STOP(child) )  len ++;
1752         }
1753         if (len > 2)
1754         {
1755             switch (stopinfo->draggable->point_type) {
1756                 case POINT_LG_BEGIN:
1757                     {
1758                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1759
1760                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
1761                         NR::Point oldbegin = NR::Point (lg->x1.computed, lg->y1.computed);
1762                         NR::Point end = NR::Point (lg->x2.computed, lg->y2.computed);
1763                         SPStop *stop = sp_first_stop(stopinfo->vector);
1764                         gdouble offset = stop->offset;
1765                         NR::Point newbegin = oldbegin + offset * (end - oldbegin);
1766                         lg->x1.computed = newbegin[NR::X];
1767                         lg->y1.computed = newbegin[NR::Y];
1768
1769                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
1770                         sp_repr_set_svg_double(repr, "x1", lg->x1.computed);
1771                         sp_repr_set_svg_double(repr, "y1", lg->y1.computed);
1772                         stop->offset = 0;
1773                         sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", 0);
1774
1775                         // iterate through midstops to set new offset values such that they won't move on canvas.
1776                         SPStop *laststop = sp_last_stop(stopinfo->vector);
1777                         stop = sp_next_stop(stop);
1778                         while ( stop != laststop ) {
1779                             stop->offset = (stop->offset - offset)/(1 - offset);
1780                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
1781                             stop = sp_next_stop(stop);
1782                         }
1783                     }
1784                     break;
1785                 case POINT_LG_END:
1786                     {
1787                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1788
1789                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
1790                         NR::Point begin = NR::Point (lg->x1.computed, lg->y1.computed);
1791                         NR::Point oldend = NR::Point (lg->x2.computed, lg->y2.computed);
1792                         SPStop *laststop = sp_last_stop(stopinfo->vector);
1793                         gdouble offset = laststop->offset;
1794                         NR::Point newend = begin + offset * (oldend - begin);
1795                         lg->x2.computed = newend[NR::X];
1796                         lg->y2.computed = newend[NR::Y];
1797
1798                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
1799                         sp_repr_set_svg_double(repr, "x2", lg->x2.computed);
1800                         sp_repr_set_svg_double(repr, "y2", lg->y2.computed);
1801                         laststop->offset = 1;
1802                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
1803
1804                         // iterate through midstops to set new offset values such that they won't move on canvas.
1805                         SPStop *stop = sp_first_stop(stopinfo->vector);
1806                         stop = sp_next_stop(stop);
1807                         while ( stop != laststop ) {
1808                             stop->offset = stop->offset / offset;
1809                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
1810                             stop = sp_next_stop(stop);
1811                         }
1812                     }
1813                     break;
1814                 case POINT_RG_CENTER:
1815                     {
1816                         SPStop *newfirst = sp_next_stop (stopinfo->spstop);
1817                         if (newfirst) {
1818                             newfirst->offset = 0;
1819                             sp_repr_set_css_double (SP_OBJECT_REPR (newfirst), "offset", 0);
1820                         }
1821                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1822                     }
1823                     break;
1824                 case POINT_RG_R1:
1825                 case POINT_RG_R2:
1826                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1827
1828                         SPRadialGradient *rg = SP_RADIALGRADIENT(stopinfo->gradient);
1829                         double oldradius = rg->r.computed;
1830                         SPStop *laststop = sp_last_stop(stopinfo->vector);
1831                         gdouble offset = laststop->offset;
1832                         double newradius = offset * oldradius;
1833                         rg->r.computed = newradius;
1834
1835                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(rg);
1836                         sp_repr_set_svg_double(repr, "r", rg->r.computed);
1837                         laststop->offset = 1;
1838                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
1839
1840                         // iterate through midstops to set new offset values such that they won't move on canvas.
1841                         SPStop *stop = sp_first_stop(stopinfo->vector);
1842                         stop = sp_next_stop(stop);
1843                         while ( stop != laststop ) {
1844                             stop->offset = stop->offset / offset;
1845                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
1846                             stop = sp_next_stop(stop);
1847                         }
1848                         break;
1849             }
1850         }
1851         else
1852         { // delete the gradient from the object. set fill to unset  FIXME: set to fill of unselected node?
1853             SPCSSAttr *css = sp_repr_css_attr_new ();
1854
1855             // stopinfo->spstop is the selected stop
1856             Inkscape::XML::Node *unselectedrepr = SP_OBJECT_REPR(stopinfo->vector)->firstChild();
1857             if (unselectedrepr == SP_OBJECT_REPR(stopinfo->spstop) ) {
1858                 unselectedrepr = unselectedrepr->next();
1859             }
1860
1861             if (unselectedrepr == NULL) {
1862                 if (stopinfo->draggable->fill_or_stroke) {
1863                     sp_repr_css_unset_property (css, "fill");
1864                 } else {
1865                     sp_repr_css_unset_property (css, "stroke");
1866                 }
1867             } else {
1868                 SPCSSAttr *stopcss = sp_repr_css_attr(unselectedrepr, "style");
1869                 if (stopinfo->draggable->fill_or_stroke) {
1870                     sp_repr_css_set_property(css, "fill", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
1871                     sp_repr_css_set_property(css, "fill-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
1872                 } else {
1873                     sp_repr_css_set_property(css, "stroke", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
1874                     sp_repr_css_set_property(css, "stroke-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
1875                 }
1876                 sp_repr_css_attr_unref (stopcss);
1877             }
1878
1879             sp_repr_css_change (SP_OBJECT_REPR (stopinfo->draggable->item), css, "style");
1880             sp_repr_css_attr_unref (css);
1881         }
1882
1883         endstoplist = g_slist_remove(endstoplist, stopinfo);
1884         delete stopinfo;
1885     }
1886
1887     if (document) {
1888         sp_document_done ( document, SP_VERB_CONTEXT_GRADIENT, _("Delete gradient stop(s)") );
1889     }
1890 }
1891
1892
1893 /*
1894   Local Variables:
1895   mode:c++
1896   c-file-style:"stroustrup"
1897   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1898   indent-tabs-mode:nil
1899   fill-column:99
1900   End:
1901 */
1902 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :