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
 346 SPObject *
 347 GrDraggable::getServer ()
 348 {
 349     if (!item)
 350         return NULL;
 351
 352     SPObject *server = NULL;
 353     if (fill_or_stroke)
 354         server = SP_OBJECT_STYLE_FILL_SERVER (item);
 355     else
 356         server = SP_OBJECT_STYLE_STROKE_SERVER (item);
 357
 358     return server;
 359 }
 360
 361
 362 // FIXME: make global function in libnr or somewhere.
 363 static NR::Point *
 364 get_snap_vector (NR::Point p, NR::Point o, double snap, double initial)
 365 {
 366     double r = NR::L2 (p - o);
 367     if (r < 1e-3)
 368         return NULL;
 369     double angle = NR::atan2 (p - o);
 370     // snap angle to snaps increments, starting from initial:
 371     double a_snapped = initial + floor((angle - initial)/snap + 0.5) * snap;
 372     // calculate the new position and subtract p to get the vector:
 373     return new NR::Point (o + r * NR::Point(cos(a_snapped), sin(a_snapped)) - p);
 374 }
 375
 376 // FIXME: make global function in libnr or somewhere.
 377 static NR::Point
 378 snap_vector_midpoint (NR::Point p, NR::Point begin, NR::Point end, double snap)
 379 {
 380     double length = NR::L2(end - begin);
 381     NR::Point be = (end - begin) / length;
 382     double r = NR::dot(p - begin, be);
 383
 384     if (r < 0.0) return begin;
 385     if (r > length) return end;
 386
 387     double snapdist = length * snap;
 388     double r_snapped = (snap==0) ? r : floor(r/(snapdist + 0.5)) * snapdist;
 389
 390     return (begin + r_snapped * be);
 391 }
 392
 393 static void
 394 gr_knot_moved_handler(SPKnot *knot, NR::Point const *ppointer, guint state, gpointer data)
 395 {
 396     GrDragger *dragger = (GrDragger *) data;
 397     GrDrag *drag = dragger->parent;
 398
 399     NR::Point p = *ppointer;
 400
 401     // FIXME: take from prefs
 402     double snap_dist = SNAP_DIST / dragger->parent->desktop->current_zoom();
 403
 404     if (state & GDK_SHIFT_MASK) {
 405         // with Shift; unsnap if we carry more than one draggable
 406         if (dragger->draggables && dragger->draggables->next) {
 407             // create a new dragger
 408             GrDragger *dr_new = new GrDragger (dragger->parent, dragger->point, NULL);
 409             dragger->parent->draggers = g_list_prepend (dragger->parent->draggers, dr_new);
 410             // relink to it all but the first draggable in the list
 411             for (GSList const* i = dragger->draggables->next; i != NULL; i = i->next) {
 412                 GrDraggable *draggable = (GrDraggable *) i->data;
 413                 dr_new->addDraggable (draggable);
 414             }
 415             dr_new->updateKnotShape();
 416             g_slist_free (dragger->draggables->next);
 417             dragger->draggables->next = NULL;
 418             dragger->updateKnotShape();
 419             dragger->updateTip();
 420         }
 421     } else if (!(state & GDK_CONTROL_MASK)) {
 422         // without Shift or Ctrl; see if we need to snap to another dragger
 423         for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 424             GrDragger *d_new = (GrDragger *) di->data;
 425             if (dragger->mayMerge(d_new) && NR::L2 (d_new->point - p) < snap_dist) {
 426
 427                 // Merge draggers:
 428                 for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 429                     GrDraggable *draggable = (GrDraggable *) i->data;
 430                     // copy draggable to d_new:
 431                     GrDraggable *da_new = new GrDraggable (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 432                     d_new->addDraggable (da_new);
 433                 }
 434
 435                 // unlink and delete this dragger
 436                 dragger->parent->draggers = g_list_remove (dragger->parent->draggers, dragger);
 437                 delete dragger;
 438
 439                 // update the new merged dragger
 440                 d_new->fireDraggables(true, false, true);
 441                 d_new->parent->updateLines();
 442                 d_new->parent->setSelected (d_new);
 443                 d_new->updateKnotShape ();
 444                 d_new->updateTip ();
 445                 d_new->updateDependencies(true);
 446                 sp_document_done (sp_desktop_document (d_new->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 447                                   _("Merge gradient handles"));
 448                 return;
 449             }
 450         }
 451     }
 452
 453     if (!((state & GDK_SHIFT_MASK) || ((state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK)))) {
 454         // Try snapping to the grid or guides
 455         SnapManager const &m = dragger->parent->desktop->namedview->snap_manager;
 456         Inkscape::SnappedPoint s = m.freeSnap(Inkscape::Snapper::SNAPPOINT_NODE, p, NULL);
 457         if (s.getDistance() < 1e6) {
 458             p = s.getPoint();
 459             sp_knot_moveto (knot, &p);
 460         } else {
 461             // No snapping so far, let's see if we need to snap to any of the levels
 462             for (guint i = 0; i < dragger->parent->hor_levels.size(); i++) {
 463                 if (fabs(p[NR::Y] - dragger->parent->hor_levels[i]) < snap_dist) {
 464                     p[NR::Y] = dragger->parent->hor_levels[i];
 465                     sp_knot_moveto (knot, &p);
 466                 }
 467             }
 468             for (guint i = 0; i < dragger->parent->vert_levels.size(); i++) {
 469                 if (fabs(p[NR::X] - dragger->parent->vert_levels[i]) < snap_dist) {
 470                     p[NR::X] = dragger->parent->vert_levels[i];
 471                     sp_knot_moveto (knot, &p);
 472                 }
 473             }
 474         }
 475     }
 476
 477     if (state & GDK_CONTROL_MASK) {
 478         unsigned snaps = abs(prefs_get_int_attribute("options.rotationsnapsperpi", "value", 12));
 479         /* 0 means no snapping. */
 480
 481         // This list will store snap vectors from all draggables of dragger
 482         GSList *snap_vectors = NULL;
 483
 484         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) {
 485             GrDraggable *draggable = (GrDraggable *) i->data;
 486
 487             NR::Point *dr_snap = NULL;
 488
 489             if (draggable->point_type == POINT_LG_BEGIN || draggable->point_type == POINT_LG_END) {
 490                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 491                     GrDragger *d_new = (GrDragger *) di->data;
 492                     if (d_new == dragger)
 493                         continue;
 494                     if (d_new->isA (draggable->item,
 495                                     draggable->point_type == POINT_LG_BEGIN? POINT_LG_END : POINT_LG_BEGIN,
 496                                     draggable->point_i,
 497                                     draggable->fill_or_stroke)) {
 498                         // found the other end of the linear gradient;
 499                         if (state & GDK_SHIFT_MASK) {
 500                             // moving linear around center
 501                             NR::Point center = NR::Point (0.5*(d_new->point + dragger->point));
 502                             dr_snap = &center;
 503                         } else {
 504                             // moving linear around the other end
 505                             dr_snap = &d_new->point;
 506                         }
 507                     }
 508                 }
 509             } else if (draggable->point_type == POINT_RG_R1 || draggable->point_type == POINT_RG_R2 || draggable->point_type == POINT_RG_FOCUS) {
 510                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 511                     GrDragger *d_new = (GrDragger *) di->data;
 512                     if (d_new == dragger)
 513                         continue;
 514                     if (d_new->isA (draggable->item,
 515                                     POINT_RG_CENTER,
 516                                     draggable->point_i,
 517                                     draggable->fill_or_stroke)) {
 518                         // found the center of the radial gradient;
 519                         dr_snap = &(d_new->point);
 520                     }
 521                 }
 522             } else if (draggable->point_type == POINT_RG_CENTER) {
 523                 // radial center snaps to hor/vert relative to its original position
 524                 dr_snap = &(dragger->point_original);
 525             }
 526
 527             NR::Point *snap_vector = NULL;
 528             if (dr_snap) {
 529                 if (state & GDK_MOD1_MASK) {
 530                     // with Alt, snap to the original angle and its perpendiculars
 531                     snap_vector = get_snap_vector (p, *dr_snap, M_PI/2, NR::atan2 (dragger->point_original - *dr_snap));
 532                 } else {
 533                     // with Ctrl, snap to M_PI/snaps
 534                     snap_vector = get_snap_vector (p, *dr_snap, M_PI/snaps, 0);
 535                 }
 536             }
 537             if (snap_vector) {
 538                 snap_vectors = g_slist_prepend (snap_vectors, snap_vector);
 539             }
 540         }
 541
 542         // Move by the smallest of snap vectors:
 543         NR::Point move(9999, 9999);
 544         for (GSList const *i = snap_vectors; i != NULL; i = i->next) {
 545             NR::Point *snap_vector = (NR::Point *) i->data;
 546             if (NR::L2(*snap_vector) < NR::L2(move))
 547                 move = *snap_vector;
 548         }
 549         if (move[NR::X] < 9999) {
 550             p += move;
 551             sp_knot_moveto (knot, &p);
 552         }
 553
 554         g_slist_free(snap_vectors);
 555     }
 556
 557     drag->keep_selection = (bool) g_list_find(drag->selected, dragger);
 558     bool scale_radial = (state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK);
 559
 560     if (drag->keep_selection) {
 561         NR::Point diff = p - dragger->point;
 562         drag->selected_move_nowrite (diff[NR::X], diff[NR::Y], scale_radial);
 563     } else {
 564         dragger->point = p;
 565         dragger->fireDraggables (false, scale_radial);
 566         dragger->updateDependencies(false);
 567     }
 568
 569 }
 570
 571
 572 static void
 573 gr_midpoint_limits(GrDragger *dragger, SPObject *server, NR::Point *begin, NR::Point *end, NR::Point *low_lim, NR::Point *high_lim, GSList **moving)
 574 {
 575
 576     GrDrag *drag = dragger->parent;
 577     // a midpoint dragger can (logically) only contain one GrDraggable
 578     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 579
 580     // get begin and end points between which dragging is allowed:
 581     // the draglimits are between knot(lowest_i - 1) and knot(highest_i + 1)
 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     if (dragger->isSelected()) {
 589         GrDragger* d_add;
 590         while ( true )
 591         {
 592             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 593             if ( d_add && g_list_find(drag->selected, d_add) ) {
 594                 lowest_i = lowest_i - 1;
 595                 *moving = g_slist_prepend(*moving, d_add);
 596                 lowest_dragger = d_add;
 597             } else {
 598                 break;
 599             }
 600         }
 601
 602         while ( true )
 603         {
 604             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 605             if ( d_add && g_list_find(drag->selected, d_add) ) {
 606                 highest_i = highest_i + 1;
 607                 *moving = g_slist_append(*moving, d_add);
 608                 highest_dragger = d_add;
 609             } else {
 610                 break;
 611             }
 612         }
 613     }
 614
 615     if ( SP_IS_LINEARGRADIENT(server) ) {
 616         guint num = SP_LINEARGRADIENT(server)->vector.stops.size();
 617         GrDragger *d_temp;
 618         if (lowest_i == 1) {
 619             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke);
 620         } else {
 621             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, lowest_i - 1, draggable->fill_or_stroke);
 622         }
 623         if (d_temp)
 624             *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)
 631             *end = d_temp->point;
 632     } else if ( SP_IS_RADIALGRADIENT(server) ) {
 633         guint num = SP_RADIALGRADIENT(server)->vector.stops.size();
 634         GrDragger *d_temp;
 635         if (lowest_i == 1) {
 636             d_temp = drag->getDraggerFor (draggable->item, POINT_RG_CENTER, 0, draggable->fill_or_stroke);
 637         } else {
 638             d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 639         }
 640         if (d_temp)
 641             *begin = d_temp->point;
 642
 643         d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 644         if (d_temp == NULL) {
 645             d_temp = drag->getDraggerFor (draggable->item, (draggable->point_type==POINT_RG_MID1) ? POINT_RG_R1 : POINT_RG_R2, num-1, draggable->fill_or_stroke);
 646         }
 647         if (d_temp)
 648             *end = d_temp->point;
 649     }
 650
 651     *low_lim  = dragger->point - (lowest_dragger->point - *begin);
 652     *high_lim = dragger->point - (highest_dragger->point - *end);
 653 }
 654
 655
 656
 657 /**
 658 Called when a midpoint knot is dragged.
 659 */
 660 static void
 661 gr_knot_moved_midpoint_handler(SPKnot *knot, NR::Point const *ppointer, guint state, gpointer data)
 662 {
 663     GrDragger *dragger = (GrDragger *) data;
 664     GrDrag *drag = dragger->parent;
 665     // a midpoint dragger can (logically) only contain one GrDraggable
 666     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 667
 668     // FIXME: take from prefs
 669     double snap_fraction = 0.1;
 670
 671     NR::Point p = *ppointer;
 672     NR::Point begin(0,0), end(0,0);
 673     NR::Point low_lim(0,0), high_lim(0,0);
 674
 675     SPObject *server = draggable->getServer();
 676
 677     GSList *moving = NULL;
 678     gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
 679
 680     if (state & GDK_CONTROL_MASK) {
 681         p = snap_vector_midpoint (p, low_lim, high_lim, snap_fraction);
 682     } else {
 683         p = snap_vector_midpoint (p, low_lim, high_lim, 0);
 684     }
 685     NR::Point displacement = p - dragger->point;
 686
 687     for (GSList const* i = moving; i != NULL; i = i->next) {
 688         GrDragger *drg = (GrDragger*) i->data;
 689         SPKnot *drgknot = drg->knot;
 690         NR::Point this_move = displacement;
 691         if (state & GDK_MOD1_MASK) {
 692             // FIXME: unify all these profiles (here, in nodepath, in tweak) in one place
 693             double alpha = 1.5;
 694             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
 695                 double x = NR::L2(drg->point - dragger->point)/NR::L2(end - dragger->point);
 696                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 697             } else { // drg is on the begin side from dragger
 698                 double x = NR::L2(drg->point - dragger->point)/NR::L2(begin - dragger->point);
 699                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 700             }
 701         }
 702         drg->point += this_move;
 703         sp_knot_moveto (drgknot, & drg->point);
 704         drg->fireDraggables (false);
 705         drg->updateDependencies(false);
 706     }
 707
 708     g_slist_free(moving);
 709
 710     drag->keep_selection = dragger->isSelected();
 711 }
 712
 713
 714
 715 static void
 716 gr_knot_grabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 717 {
 718     GrDragger *dragger = (GrDragger *) data;
 719
 720     sp_canvas_force_full_redraw_after_interruptions(dragger->parent->desktop->canvas, 5);
 721 }
 722
 723 /**
 724 Called when the mouse releases a dragger knot; changes gradient writing to repr, updates other draggers if needed
 725 */
 726 static void
 727 gr_knot_ungrabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 728 {
 729     GrDragger *dragger = (GrDragger *) data;
 730
 731     sp_canvas_end_forced_full_redraws(dragger->parent->desktop->canvas);
 732
 733     dragger->point_original = dragger->point = knot->pos;
 734
 735     if ((state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK)) {
 736         dragger->fireDraggables (true, true);
 737     } else {
 738         dragger->fireDraggables (true);
 739     }
 740
 741     for (GList *i = dragger->parent->selected; i != NULL; i = i->next) {
 742         GrDragger *d = (GrDragger *) i->data;
 743         if (d == dragger)
 744             continue;
 745         d->fireDraggables (true);
 746     }
 747
 748     // make this dragger selected
 749     if (!dragger->parent->keep_selection) {
 750         dragger->parent->setSelected (dragger);
 751     }
 752     dragger->parent->keep_selection = false;
 753
 754     dragger->updateDependencies(true);
 755
 756     // we did an undoable action
 757     sp_document_done (sp_desktop_document (dragger->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 758                       _("Move gradient handle"));
 759 }
 760
 761 /**
 762 Called when a dragger knot is clicked; selects the dragger or deletes it depending on the
 763 state of the keyboard keys
 764 */
 765 static void
 766 gr_knot_clicked_handler(SPKnot *knot, guint state, gpointer data)
 767 {
 768     GrDragger *dragger = (GrDragger *) data;
 769     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 770     if (!draggable) return;
 771
 772     if ( (state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK ) ) {
 773     // delete this knot from vector
 774         SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
 775         gradient = sp_gradient_get_vector (gradient, false);
 776         if (gradient->vector.stops.size() > 2) { // 2 is the minimum
 777                 SPStop *stop = NULL;
 778                 switch (draggable->point_type) {  // if we delete first or last stop, move the next/previous to the edge
 779                 case POINT_LG_BEGIN:
 780                 case POINT_RG_CENTER:
 781                     stop = sp_first_stop(gradient);
 782                         {
 783                             SPStop *next = sp_next_stop (stop);
 784                                 if (next) {
 785                                         next->offset = 0;
 786                                         sp_repr_set_css_double (SP_OBJECT_REPR (next), "offset", 0);
 787                                 }
 788                         }
 789                     break;
 790                 case POINT_LG_END:
 791                 case POINT_RG_R1:
 792                 case POINT_RG_R2:
 793                     stop = sp_last_stop(gradient);
 794                     {
 795                             SPStop *prev = sp_prev_stop (stop, gradient);
 796                             if (prev) {
 797                                     prev->offset = 1;
 798                                     sp_repr_set_css_double (SP_OBJECT_REPR (prev), "offset", 1);
 799                             }
 800                         }
 801                     break;
 802                 case POINT_LG_MID:
 803                 case POINT_RG_MID1:
 804                 case POINT_RG_MID2:
 805                     stop = sp_get_stop_i(gradient, draggable->point_i);
 806                     break;
 807                 }
 808
 809                 SP_OBJECT_REPR(gradient)->removeChild(SP_OBJECT_REPR(stop));
 810                 sp_document_done (SP_OBJECT_DOCUMENT (gradient), SP_VERB_CONTEXT_GRADIENT,
 811                                   _("Delete gradient stop"));
 812         }
 813     } else {
 814     // select the dragger
 815         dragger->point_original = dragger->point;
 816
 817         if ( state & GDK_SHIFT_MASK ) {
 818             dragger->parent->setSelected (dragger, true, false);
 819         } else {
 820             dragger->parent->setSelected (dragger);
 821         }
 822     }
 823 }
 824
 825 /**
 826 Called when a dragger knot is doubleclicked; opens gradient editor with the stop from the first draggable
 827 */
 828 static void
 829 gr_knot_doubleclicked_handler (SPKnot *knot, guint state, gpointer data)
 830 {
 831     GrDragger *dragger = (GrDragger *) data;
 832
 833     dragger->point_original = dragger->point;
 834
 835     if (dragger->draggables == NULL)
 836         return;
 837
 838     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 839     sp_item_gradient_edit_stop (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 840 }
 841
 842 /**
 843 Act upon all draggables of the dragger, setting them to the dragger's point
 844 */
 845 void
 846 GrDragger::fireDraggables (bool write_repr, bool scale_radial, bool merging_focus)
 847 {
 848     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 849         GrDraggable *draggable = (GrDraggable *) i->data;
 850
 851         // set local_change flag so that selection_changed callback does not regenerate draggers
 852         this->parent->local_change = true;
 853
 854         // change gradient, optionally writing to repr; prevent focus from moving if it's snapped
 855         // to the center, unless it's the first update upon merge when we must snap it to the point
 856         if (merging_focus ||
 857             !(draggable->point_type == POINT_RG_FOCUS && this->isA(draggable->item, POINT_RG_CENTER, draggable->point_i, draggable->fill_or_stroke)))
 858         {
 859             sp_item_gradient_set_coords (draggable->item, draggable->point_type, draggable->point_i, this->point, draggable->fill_or_stroke, write_repr, scale_radial);
 860         }
 861     }
 862 }
 863
 864 /**
 865 Checks if the dragger has a draggable with this point_type
 866  */
 867 bool
 868 GrDragger::isA (gint point_type)
 869 {
 870     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 871         GrDraggable *draggable = (GrDraggable *) i->data;
 872         if (draggable->point_type == point_type) {
 873             return true;
 874         }
 875     }
 876     return false;
 877 }
 878
 879 /**
 880 Checks if the dragger has a draggable with this item, point_type, fill_or_stroke
 881  */
 882 bool
 883 GrDragger::isA (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
 884 {
 885     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 886         GrDraggable *draggable = (GrDraggable *) i->data;
 887         if ( (draggable->point_type == point_type) && (draggable->point_i == point_i) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
 888             return true;
 889         }
 890     }
 891     return false;
 892 }
 893
 894 bool
 895 GrDraggable::mayMerge (GrDraggable *da2)
 896 {
 897     if ((this->item == da2->item) && (this->fill_or_stroke == da2->fill_or_stroke)) {
 898         // we must not merge the points of the same gradient!
 899         if (!((this->point_type == POINT_RG_FOCUS && da2->point_type == POINT_RG_CENTER) ||
 900               (this->point_type == POINT_RG_CENTER && da2->point_type == POINT_RG_FOCUS))) {
 901             // except that we can snap center and focus together
 902             return false;
 903         }
 904     }
 905     // disable merging of midpoints.
 906     if ( (this->point_type == POINT_LG_MID) || (da2->point_type == POINT_LG_MID)
 907          || (this->point_type == POINT_RG_MID1) || (da2->point_type == POINT_RG_MID1)
 908          || (this->point_type == POINT_RG_MID2) || (da2->point_type == POINT_RG_MID2) )
 909         return false;
 910
 911     return true;
 912 }
 913
 914 bool
 915 GrDragger::mayMerge (GrDragger *other)
 916 {
 917     if (this == other)
 918         return false;
 919
 920     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
 921         GrDraggable *da1 = (GrDraggable *) i->data;
 922         for (GSList const* j = other->draggables; j != NULL; j = j->next) { // for all draggables of other
 923             GrDraggable *da2 = (GrDraggable *) j->data;
 924             if (!da1->mayMerge(da2))
 925                 return false;
 926         }
 927     }
 928     return true;
 929 }
 930
 931 bool
 932 GrDragger::mayMerge (GrDraggable *da2)
 933 {
 934     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
 935         GrDraggable *da1 = (GrDraggable *) i->data;
 936         if (!da1->mayMerge(da2))
 937             return false;
 938     }
 939     return true;
 940 }
 941
 942 /**
 943 Updates the statusbar tip of the dragger knot, based on its draggables
 944  */
 945 void
 946 GrDragger::updateTip ()
 947 {
 948         if (this->knot && this->knot->tip) {
 949                 g_free (this->knot->tip);
 950                 this->knot->tip = NULL;
 951         }
 952
 953     if (g_slist_length (this->draggables) == 1) {
 954         GrDraggable *draggable = (GrDraggable *) this->draggables->data;
 955         char *item_desc = sp_item_description(draggable->item);
 956         switch (draggable->point_type) {
 957             case POINT_LG_MID:
 958             case POINT_RG_MID1:
 959             case POINT_RG_MID2:
 960                 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"),
 961                                                    _(gr_knot_descr[draggable->point_type]),
 962                                                    draggable->point_i,
 963                                                    item_desc,
 964                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
 965                 break;
 966
 967             default:
 968                 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"),
 969                                                    _(gr_knot_descr[draggable->point_type]),
 970                                                    item_desc,
 971                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
 972                 break;
 973         }
 974         g_free(item_desc);
 975     } else if (g_slist_length (draggables) == 2 && isA (POINT_RG_CENTER) && isA (POINT_RG_FOCUS)) {
 976         this->knot->tip = g_strdup_printf (_("Radial gradient <b>center</b> and <b>focus</b>; drag with <b>Shift</b> to separate focus"));
 977     } else {
 978         int length = g_slist_length (this->draggables);
 979         this->knot->tip = g_strdup_printf (ngettext("Gradient point shared by <b>%d</b> gradient; drag with <b>Shift</b> to separate",
 980                                                     "Gradient point shared by <b>%d</b> gradients; drag with <b>Shift</b> to separate",
 981                                                     length),
 982                                            length);
 983     }
 984 }
 985
 986 /**
 987 Adds a draggable to the dragger
 988  */
 989 void
 990 GrDragger::updateKnotShape ()
 991 {
 992     if (!draggables)
 993         return;
 994     GrDraggable *last = (GrDraggable *) g_slist_last(draggables)->data;
 995     g_object_set (G_OBJECT (this->knot->item), "shape", gr_knot_shapes[last->point_type], NULL);
 996 }
 997
 998 /**
 999 Adds a draggable to the dragger
1000  */
1001 void
1002 GrDragger::addDraggable (GrDraggable *draggable)
1003 {
1004     this->draggables = g_slist_prepend (this->draggables, draggable);
1005
1006     this->updateTip();
1007 }
1008
1009
1010 /**
1011 Moves this dragger to the point of the given draggable, acting upon all other draggables
1012  */
1013 void
1014 GrDragger::moveThisToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1015 {
1016     this->point = sp_item_gradient_get_coords (item, point_type, point_i, fill_or_stroke);
1017     this->point_original = this->point;
1018
1019     sp_knot_moveto (this->knot, &(this->point));
1020
1021     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1022         GrDraggable *da = (GrDraggable *) i->data;
1023         if ( (da->item == item) &&
1024              (point_type == -1 || da->point_type == point_type) &&
1025              (point_i == -1 || da->point_i == point_i) &&
1026              (da->fill_or_stroke == fill_or_stroke) ) {
1027             continue;
1028         }
1029         sp_item_gradient_set_coords (da->item, da->point_type, da->point_i, this->point, da->fill_or_stroke, write_repr, false);
1030     }
1031     // FIXME: here we should also call this->updateDependencies(write_repr); to propagate updating, but how to prevent loops?
1032 }
1033
1034
1035 /**
1036 Moves all midstop draggables that depend on this one
1037  */
1038 void
1039 GrDragger::updateMidstopDependencies (GrDraggable *draggable, bool write_repr) {
1040     SPObject *server = draggable->getServer();
1041     if (!server)
1042         return;
1043     guint num = SP_GRADIENT(server)->vector.stops.size();
1044     if (num <= 2) return;
1045
1046     if ( SP_IS_LINEARGRADIENT(server) ) {
1047         for ( guint i = 1; i < num - 1; i++ ) {
1048             this->moveOtherToDraggable (draggable->item, POINT_LG_MID, i, draggable->fill_or_stroke, write_repr);
1049         }
1050     } else  if ( SP_IS_RADIALGRADIENT(server) ) {
1051         for ( guint i = 1; i < num - 1; i++ ) {
1052             this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, i, draggable->fill_or_stroke, write_repr);
1053             this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, i, draggable->fill_or_stroke, write_repr);
1054         }
1055     }
1056 }
1057
1058
1059 /**
1060 Moves all draggables that depend on this one
1061  */
1062 void
1063 GrDragger::updateDependencies (bool write_repr)
1064 {
1065     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1066         GrDraggable *draggable = (GrDraggable *) i->data;
1067         switch (draggable->point_type) {
1068             case POINT_LG_BEGIN:
1069                 {
1070                     // the end point is dependent only when dragging with ctrl+shift
1071                     this->moveOtherToDraggable (draggable->item, POINT_LG_END, -1, draggable->fill_or_stroke, write_repr);
1072
1073                     this->updateMidstopDependencies (draggable, write_repr);
1074                 }
1075                 break;
1076             case POINT_LG_END:
1077                 {
1078                     // the begin point is dependent only when dragging with ctrl+shift
1079                     this->moveOtherToDraggable (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke, write_repr);
1080
1081                     this->updateMidstopDependencies (draggable, write_repr);
1082                 }
1083                 break;
1084             case POINT_LG_MID:
1085                 // no other nodes depend on mid points.
1086                 break;
1087             case POINT_RG_R2:
1088                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1089                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1090                 this->updateMidstopDependencies (draggable, write_repr);
1091                 break;
1092             case POINT_RG_R1:
1093                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1094                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1095                 this->updateMidstopDependencies (draggable, write_repr);
1096                 break;
1097             case POINT_RG_CENTER:
1098                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1099                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1100                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1101                 this->updateMidstopDependencies (draggable, write_repr);
1102                 break;
1103             case POINT_RG_FOCUS:
1104                 // nothing can depend on that
1105                 break;
1106             case POINT_RG_MID1:
1107                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, draggable->point_i, draggable->fill_or_stroke, write_repr);
1108                 break;
1109             case POINT_RG_MID2:
1110                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, draggable->point_i, draggable->fill_or_stroke, write_repr);
1111                 break;
1112             default:
1113                 break;
1114         }
1115     }
1116 }
1117
1118
1119
1120 GrDragger::GrDragger (GrDrag *parent, NR::Point p, GrDraggable *draggable)
1121 {
1122     this->draggables = NULL;
1123
1124     this->parent = parent;
1125
1126     this->point = p;
1127     this->point_original = p;
1128
1129     // create the knot
1130     this->knot = sp_knot_new (parent->desktop, NULL);
1131     this->knot->setMode(SP_KNOT_MODE_XOR);
1132     this->knot->setFill(GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_NORMAL);
1133     this->knot->setStroke(0x000000ff, 0x000000ff, 0x000000ff);
1134     sp_knot_update_ctrl(this->knot);
1135
1136     // move knot to the given point
1137     sp_knot_set_position (this->knot, &p, SP_KNOT_STATE_NORMAL);
1138     sp_knot_show (this->knot);
1139
1140     // connect knot's signals
1141     if ( (draggable)  // it can be NULL if a node in unsnapped (eg. focus point unsnapped from center)
1142                        // luckily, midstops never snap to other nodes so are never unsnapped...
1143          && ( (draggable->point_type == POINT_LG_MID)
1144               || (draggable->point_type == POINT_RG_MID1)
1145               || (draggable->point_type == POINT_RG_MID2) ) )
1146     {
1147         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_midpoint_handler), this);
1148     } else {
1149         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_handler), this);
1150     }
1151     g_signal_connect (G_OBJECT (this->knot), "clicked", G_CALLBACK (gr_knot_clicked_handler), this);
1152     g_signal_connect (G_OBJECT (this->knot), "doubleclicked", G_CALLBACK (gr_knot_doubleclicked_handler), this);
1153     g_signal_connect (G_OBJECT (this->knot), "grabbed", G_CALLBACK (gr_knot_grabbed_handler), this);
1154     g_signal_connect (G_OBJECT (this->knot), "ungrabbed", G_CALLBACK (gr_knot_ungrabbed_handler), this);
1155
1156     // add the initial draggable
1157     if (draggable)
1158         this->addDraggable (draggable);
1159     updateKnotShape();
1160 }
1161
1162 GrDragger::~GrDragger ()
1163 {
1164     // unselect if it was selected
1165     this->parent->setDeselected(this);
1166
1167     // disconnect signals
1168     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_moved_handler), this);
1169     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_clicked_handler), this);
1170     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_doubleclicked_handler), this);
1171     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_grabbed_handler), this);
1172     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_ungrabbed_handler), this);
1173
1174     /* unref should call destroy */
1175     g_object_unref (G_OBJECT (this->knot));
1176
1177     // delete all draggables
1178     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1179         delete ((GrDraggable *) i->data);
1180     }
1181     g_slist_free (this->draggables);
1182     this->draggables = NULL;
1183 }
1184
1185 /**
1186 Select the dragger which has the given draggable.
1187 */
1188 GrDragger *
1189 GrDrag::getDraggerFor (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1190 {
1191     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1192         GrDragger *dragger = (GrDragger *) i->data;
1193         for (GSList const* j = dragger->draggables; j != NULL; j = j->next) {
1194             GrDraggable *da2 = (GrDraggable *) j->data;
1195             if ( (da2->item == item) &&
1196                  (point_type == -1 || da2->point_type == point_type) && // -1 means this does not matter
1197                  (point_i == -1 || da2->point_i == point_i) && // -1 means this does not matter
1198                  (da2->fill_or_stroke == fill_or_stroke)) {
1199                 return (dragger);
1200             }
1201         }
1202     }
1203     return NULL;
1204 }
1205
1206
1207 void
1208 GrDragger::moveOtherToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1209 {
1210     GrDragger *d = this->parent->getDraggerFor (item, point_type, point_i, fill_or_stroke);
1211     if (d && d !=  this) {
1212         d->moveThisToDraggable (item, point_type, point_i, fill_or_stroke, write_repr);
1213     }
1214 }
1215
1216
1217 /**
1218   Draw this dragger as selected
1219 */
1220 void
1221 GrDragger::select()
1222 {
1223     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_SELECTED;
1224     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_SELECTED, NULL);
1225 }
1226
1227 /**
1228   Draw this dragger as normal (deselected)
1229 */
1230 void
1231 GrDragger::deselect()
1232 {
1233     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_NORMAL;
1234     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_NORMAL, NULL);
1235 }
1236
1237 bool
1238 GrDragger::isSelected()
1239 {
1240     return g_list_find (parent->selected, this);
1241 }
1242
1243 /**
1244 \brief Deselect all stops/draggers (private)
1245 */
1246 void
1247 GrDrag::deselect_all()
1248 {
1249     while (selected) {
1250         ( (GrDragger*) selected->data)->deselect();
1251         selected = g_list_remove(selected, selected->data);
1252     }
1253 }
1254
1255 /**
1256 \brief Deselect all stops/draggers (public; emits signal)
1257 */
1258 void
1259 GrDrag::deselectAll()
1260 {
1261     deselect_all();
1262     this->desktop->emitToolSubselectionChanged(NULL);
1263 }
1264
1265 /**
1266 \brief Select all stops/draggers
1267 */
1268 void
1269 GrDrag::selectAll()
1270 {
1271     for (GList *l = this->draggers; l != NULL; l = l->next) {
1272         GrDragger *d = ((GrDragger *) l->data);
1273         setSelected (d, true, true);
1274     }
1275 }
1276
1277 /**
1278 \brief Select all stops/draggers that match the coords
1279 */
1280 void
1281 GrDrag::selectByCoords(std::vector<NR::Point> coords)
1282 {
1283     for (GList *l = this->draggers; l != NULL; l = l->next) {
1284         GrDragger *d = ((GrDragger *) l->data);
1285         for (guint k = 0; k < coords.size(); k++) {
1286             if (NR::L2 (d->point - coords[k]) < 1e-4) {
1287                 setSelected (d, true, true);
1288             }
1289         }
1290     }
1291 }
1292
1293 /**
1294 \brief Select a dragger
1295 \param dragger       The dragger to select
1296 \param add_to_selection   If true, add to selection, otherwise deselect others
1297 \param override      If true, always select this node, otherwise toggle selected status
1298 */
1299 void
1300 GrDrag::setSelected (GrDragger *dragger, bool add_to_selection, bool override)
1301 {
1302     GrDragger *seldragger = NULL;
1303
1304     if (add_to_selection) {
1305         if (!dragger) return;
1306         if (override) {
1307             if (!g_list_find(selected, dragger)) {
1308                 selected = g_list_prepend(selected, dragger);
1309             }
1310             dragger->select();
1311             seldragger = dragger;
1312         } else { // toggle
1313             if (g_list_find(selected, dragger)) {
1314                 selected = g_list_remove(selected, dragger);
1315                 dragger->deselect();
1316                 if (selected) {
1317                     seldragger = (GrDragger*) selected->data; // select the dragger that is first in the list
1318                 }
1319             } else {
1320                 selected = g_list_prepend(selected, dragger);
1321                 dragger->select();
1322                 seldragger = dragger;
1323             }
1324         }
1325     } else {
1326         deselect_all();
1327         if (dragger) {
1328             selected = g_list_prepend(selected, dragger);
1329             dragger->select();
1330             seldragger = dragger;
1331         }
1332     }
1333     if (seldragger) {
1334         this->desktop->emitToolSubselectionChanged((gpointer) seldragger);
1335     }
1336 }
1337
1338 /**
1339 \brief Deselect a dragger
1340 \param dragger       The dragger to deselect
1341 */
1342 void
1343 GrDrag::setDeselected (GrDragger *dragger)
1344 {
1345     if (g_list_find(selected, dragger)) {
1346         selected = g_list_remove(selected, dragger);
1347         dragger->deselect();
1348     }
1349     this->desktop->emitToolSubselectionChanged((gpointer) (selected ? selected->data : NULL ));
1350 }
1351
1352
1353
1354 /**
1355 Create a line from p1 to p2 and add it to the lines list
1356  */
1357 void
1358 GrDrag::addLine (NR::Point p1, NR::Point p2, guint32 rgba)
1359 {
1360     SPCanvasItem *line = sp_canvas_item_new(sp_desktop_controls(this->desktop),
1361                                                             SP_TYPE_CTRLLINE, NULL);
1362     sp_ctrlline_set_coords(SP_CTRLLINE(line), p1, p2);
1363     if (rgba != GR_LINE_COLOR_FILL) // fill is the default, so don't set color for it to speed up redraw
1364         sp_ctrlline_set_rgba32 (SP_CTRLLINE(line), rgba);
1365     sp_canvas_item_show (line);
1366     this->lines = g_slist_append (this->lines, line);
1367 }
1368
1369 /**
1370 If there already exists a dragger within MERGE_DIST of p, add the draggable to it; otherwise create
1371 new dragger and add it to draggers list
1372  */
1373 void
1374 GrDrag::addDragger (GrDraggable *draggable)
1375 {
1376     NR::Point p = sp_item_gradient_get_coords (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
1377
1378     for (GList *i = this->draggers; i != NULL; i = i->next) {
1379         GrDragger *dragger = (GrDragger *) i->data;
1380         if (dragger->mayMerge (draggable) && NR::L2 (dragger->point - p) < MERGE_DIST) {
1381             // distance is small, merge this draggable into dragger, no need to create new dragger
1382             dragger->addDraggable (draggable);
1383             dragger->updateKnotShape();
1384             return;
1385         }
1386     }
1387
1388     GrDragger *new_dragger = new GrDragger(this, p, draggable);
1389     // fixme: draggers should be added AFTER the last one: this way tabbing through them will be from begin to end.
1390     this->draggers = g_list_append (this->draggers, new_dragger);
1391 }
1392
1393 /**
1394 Add draggers for the radial gradient rg on item
1395 */
1396 void
1397 GrDrag::addDraggersRadial (SPRadialGradient *rg, SPItem *item, bool fill_or_stroke)
1398 {
1399     addDragger (new GrDraggable (item, POINT_RG_CENTER, 0, fill_or_stroke));
1400     guint num = rg->vector.stops.size();
1401     if (num > 2) {
1402         for ( guint i = 1; i < num - 1; i++ ) {
1403             addDragger (new GrDraggable (item, POINT_RG_MID1, i, fill_or_stroke));
1404         }
1405     }
1406     addDragger (new GrDraggable (item, POINT_RG_R1, num-1, fill_or_stroke));
1407     if (num > 2) {
1408         for ( guint i = 1; i < num - 1; i++ ) {
1409             addDragger (new GrDraggable (item, POINT_RG_MID2, i, fill_or_stroke));
1410         }
1411     }
1412     addDragger (new GrDraggable (item, POINT_RG_R2, num-1, fill_or_stroke));
1413     addDragger (new GrDraggable (item, POINT_RG_FOCUS, 0, fill_or_stroke));
1414 }
1415
1416 /**
1417 Add draggers for the linear gradient lg on item
1418 */
1419 void
1420 GrDrag::addDraggersLinear (SPLinearGradient *lg, SPItem *item, bool fill_or_stroke)
1421 {
1422     addDragger (new GrDraggable (item, POINT_LG_BEGIN, 0, fill_or_stroke));
1423     guint num = lg->vector.stops.size();
1424     if (num > 2) {
1425         for ( guint i = 1; i < num - 1; i++ ) {
1426             addDragger (new GrDraggable (item, POINT_LG_MID, i, fill_or_stroke));
1427         }
1428     }
1429     addDragger (new GrDraggable (item, POINT_LG_END, num-1, fill_or_stroke));
1430 }
1431
1432 /**
1433 Artificially grab the knot of the dragger with this draggable; used by the gradient context
1434 */
1435 void
1436 GrDrag::grabKnot (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, gint x, gint y, guint32 etime)
1437 {
1438     GrDragger *dragger = getDraggerFor (item, point_type, point_i, fill_or_stroke);
1439     if (dragger) {
1440         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1441     }
1442 }
1443
1444 /**
1445 Regenerates the draggers list from the current selection; is called when selection is changed or
1446 modified, also when a radial dragger needs to update positions of other draggers in the gradient
1447 */
1448 void
1449 GrDrag::updateDraggers ()
1450 {
1451     while (selected) {
1452         selected = g_list_remove(selected, selected->data);
1453     }
1454     // delete old draggers
1455     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1456         delete ((GrDragger *) i->data);
1457     }
1458     g_list_free (this->draggers);
1459     this->draggers = NULL;
1460
1461     g_return_if_fail (this->selection != NULL);
1462
1463     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1464
1465         SPItem *item = SP_ITEM(i->data);
1466         SPStyle *style = SP_OBJECT_STYLE (item);
1467
1468         if (style && (style->fill.isPaintserver())) {
1469             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1470             if (SP_IS_LINEARGRADIENT (server)) {
1471                 addDraggersLinear (SP_LINEARGRADIENT (server), item, true);
1472             } else if (SP_IS_RADIALGRADIENT (server)) {
1473                 addDraggersRadial (SP_RADIALGRADIENT (server), item, true);
1474             }
1475         }
1476
1477         if (style && (style->stroke.isPaintserver())) {
1478             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1479             if (SP_IS_LINEARGRADIENT (server)) {
1480                 addDraggersLinear (SP_LINEARGRADIENT (server), item, false);
1481             } else if (SP_IS_RADIALGRADIENT (server)) {
1482                 addDraggersRadial (SP_RADIALGRADIENT (server), item, false);
1483             }
1484         }
1485     }
1486 }
1487
1488 /**
1489 Regenerates the lines list from the current selection; is called on each move of a dragger, so that
1490 lines are always in sync with the actual gradient
1491 */
1492 void
1493 GrDrag::updateLines ()
1494 {
1495     // delete old lines
1496     for (GSList const *i = this->lines; i != NULL; i = i->next) {
1497         gtk_object_destroy( GTK_OBJECT (i->data));
1498     }
1499     g_slist_free (this->lines);
1500     this->lines = NULL;
1501
1502     g_return_if_fail (this->selection != NULL);
1503
1504     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1505
1506         SPItem *item = SP_ITEM(i->data);
1507
1508         SPStyle *style = SP_OBJECT_STYLE (item);
1509
1510         if (style && (style->fill.isPaintserver())) {
1511             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1512             if (SP_IS_LINEARGRADIENT (server)) {
1513                 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);
1514             } else if (SP_IS_RADIALGRADIENT (server)) {
1515                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, true);
1516                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, true), GR_LINE_COLOR_FILL);
1517                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, true), GR_LINE_COLOR_FILL);
1518             }
1519         }
1520
1521         if (style && (style->stroke.isPaintserver())) {
1522             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1523             if (SP_IS_LINEARGRADIENT (server)) {
1524                 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);
1525             } else if (SP_IS_RADIALGRADIENT (server)) {
1526                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, false);
1527                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, false), GR_LINE_COLOR_STROKE);
1528                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, false), GR_LINE_COLOR_STROKE);
1529             }
1530         }
1531     }
1532 }
1533
1534 /**
1535 Regenerates the levels list from the current selection
1536 */
1537 void
1538 GrDrag::updateLevels ()
1539 {
1540     hor_levels.clear();
1541     vert_levels.clear();
1542
1543     g_return_if_fail (this->selection != NULL);
1544
1545     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1546         SPItem *item = SP_ITEM(i->data);
1547         NR::Maybe<NR::Rect> rect = sp_item_bbox_desktop (item);
1548         if (rect) {
1549             // Remember the edges of the bbox and the center axis
1550             hor_levels.push_back(rect->min()[NR::Y]);
1551             hor_levels.push_back(rect->max()[NR::Y]);
1552             hor_levels.push_back(0.5 * (rect->min()[NR::Y] + rect->max()[NR::Y]));
1553             vert_levels.push_back(rect->min()[NR::X]);
1554             vert_levels.push_back(rect->max()[NR::X]);
1555             vert_levels.push_back(0.5 * (rect->min()[NR::X] + rect->max()[NR::X]));
1556         }
1557     }
1558 }
1559
1560 void
1561 GrDrag::selected_reverse_vector ()
1562 {
1563     if (selected == NULL)
1564         return;
1565
1566     for (GSList const* i = ( (GrDragger*) selected->data )->draggables; i != NULL; i = i->next) {
1567         GrDraggable *draggable = (GrDraggable *) i->data;
1568
1569         sp_item_gradient_reverse_vector (draggable->item, draggable->fill_or_stroke);
1570     }
1571 }
1572
1573 void
1574 GrDrag::selected_move_nowrite (double x, double y, bool scale_radial)
1575 {
1576     selected_move (x, y, false, scale_radial);
1577 }
1578
1579 void
1580 GrDrag::selected_move (double x, double y, bool write_repr, bool scale_radial)
1581 {
1582     if (selected == NULL)
1583         return;
1584
1585     bool did = false;
1586
1587     for (GList *i = selected; i != NULL; i = i->next) {
1588         GrDragger *d = (GrDragger *) i->data;
1589
1590         if (!d->isA(POINT_LG_MID) && !d->isA(POINT_RG_MID1) && !d->isA(POINT_RG_MID2)) {
1591             // if this is a an endpoint,
1592
1593             // Moving an rg center moves its focus and radii as well.
1594             // therefore, if this is a focus or radius and if selection
1595             // contains the center as well, do not move this one
1596             if (d->isA(POINT_RG_R1) || d->isA(POINT_RG_R2) ||
1597                 (d->isA(POINT_RG_FOCUS) && !d->isA(POINT_RG_CENTER))) {
1598                 bool skip_radius_with_center = false;
1599                 for (GList *di = selected; di != NULL; di = di->next) {
1600                     GrDragger *d_new = (GrDragger *) di->data;
1601                     if (d_new->isA (((GrDraggable *) d->draggables->data)->item,
1602                                     POINT_RG_CENTER,
1603                                     0,
1604                                     ((GrDraggable *) d->draggables->data)->fill_or_stroke)) {
1605                         // FIXME: here we take into account only the first draggable!
1606                         skip_radius_with_center = true;
1607                     }
1608                 }
1609                 if (skip_radius_with_center)
1610                     continue;
1611             }
1612
1613             did = true;
1614             d->point += NR::Point (x, y);
1615             d->point_original = d->point;
1616             sp_knot_moveto (d->knot, &(d->point));
1617
1618             d->fireDraggables (write_repr, scale_radial);
1619
1620             d->updateDependencies(write_repr);
1621         }
1622
1623         if (write_repr && did) {
1624             // we did an undoable action
1625             sp_document_maybe_done (sp_desktop_document (desktop), "grmoveh", SP_VERB_CONTEXT_GRADIENT,
1626                                     _("Move gradient handle(s)"));
1627             return;
1628         }
1629
1630     }
1631
1632     if (!did) { // none of the end draggers are selected, so let's try to move the mids
1633
1634         GrDragger *dragger = (GrDragger *) selected->data;
1635         // a midpoint dragger can (logically) only contain one GrDraggable
1636         GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
1637
1638         NR::Point begin(0,0), end(0,0);
1639         NR::Point low_lim(0,0), high_lim(0,0);
1640
1641         SPObject *server = draggable->getServer();
1642         GSList *moving = NULL;
1643         gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
1644
1645         NR::Point p(x, y);
1646         p = snap_vector_midpoint (dragger->point + p, low_lim, high_lim, 0);
1647         NR::Point displacement = p - dragger->point;
1648
1649         for (GSList const* i = moving; i != NULL; i = i->next) {
1650             GrDragger *drg = (GrDragger*) i->data;
1651             SPKnot *drgknot = drg->knot;
1652             drg->point += displacement;
1653             sp_knot_moveto (drgknot, & drg->point);
1654             drg->fireDraggables (true);
1655             drg->updateDependencies(true);
1656             did = true;
1657         }
1658
1659         g_slist_free(moving);
1660
1661         if (write_repr && did) {
1662             // we did an undoable action
1663             sp_document_maybe_done (sp_desktop_document (desktop), "grmovem", SP_VERB_CONTEXT_GRADIENT,
1664                                     _("Move gradient mid stop(s)"));
1665         }
1666     }
1667 }
1668
1669 void
1670 GrDrag::selected_move_screen (double x, double y)
1671 {
1672     gdouble zoom = desktop->current_zoom();
1673     gdouble zx = x / zoom;
1674     gdouble zy = y / zoom;
1675
1676     selected_move (zx, zy);
1677 }
1678
1679 /**
1680 Select the knot next to the last selected one and deselect all other selected.
1681 */
1682 void
1683 GrDrag::select_next ()
1684 {
1685     if (selected == NULL || g_list_find(draggers, selected->data)->next == NULL) {
1686         if (draggers)
1687             setSelected ((GrDragger *) draggers->data);
1688     } else {
1689         setSelected ((GrDragger *) g_list_find(draggers, selected->data)->next->data);
1690     }
1691 }
1692
1693 /**
1694 Select the knot previous from the last selected one and deselect all other selected.
1695 */
1696 void
1697 GrDrag::select_prev ()
1698 {
1699     if (selected == NULL || g_list_find(draggers, selected->data)->prev == NULL) {
1700         if (draggers)
1701             setSelected ((GrDragger *) g_list_last (draggers)->data);
1702     } else {
1703         setSelected ((GrDragger *) g_list_find(draggers, selected->data)->prev->data);
1704     }
1705 }
1706
1707
1708 // FIXME: i.m.o. an ugly function that I just made to work, but... aargh! (Johan)
1709 void
1710 GrDrag::deleteSelected (bool just_one)
1711 {
1712     if (!selected) return;
1713
1714     SPDocument *document = false;
1715
1716     struct StructStopInfo {
1717         SPStop * spstop;
1718         GrDraggable * draggable;
1719         SPGradient * gradient;
1720         SPGradient * vector;
1721     };
1722
1723     GSList *midstoplist = NULL;  // list of stops that must be deleted (will be deleted first)
1724     GSList *endstoplist = NULL;  // list of stops that must be deleted
1725     while (selected) {
1726         GrDragger *dragger = (GrDragger*) selected->data;
1727         for (GSList * drgble = dragger->draggables; drgble != NULL; drgble = drgble->next) {
1728             GrDraggable *draggable = (GrDraggable*) drgble->data;
1729             SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
1730             SPGradient *vector   = sp_gradient_get_forked_vector_if_necessary (gradient, false);
1731
1732             switch (draggable->point_type) {
1733                 case POINT_LG_MID:
1734                 case POINT_RG_MID1:
1735                 case POINT_RG_MID2:
1736                     {
1737                         SPStop *stop = sp_get_stop_i(vector, draggable->point_i);
1738                         // check if already present in list. (e.g. when both RG_MID1 and RG_MID2 were selected)
1739                         bool present = false;
1740                         for (GSList const * l = midstoplist; l != NULL; l = l->next) {
1741                             if ( (SPStop*)l->data == stop ) {
1742                                 present = true;
1743                                 break; // no need to search further.
1744                             }
1745                         }
1746                         if (!present)
1747                             midstoplist = g_slist_append(midstoplist, stop);
1748                     }
1749                     break;
1750                 case POINT_LG_BEGIN:
1751                 case POINT_LG_END:
1752                 case POINT_RG_CENTER:
1753                 case POINT_RG_R1:
1754                 case POINT_RG_R2:
1755                     {
1756                         SPStop *stop = NULL;
1757                         if ( (draggable->point_type == POINT_LG_BEGIN) || (draggable->point_type == POINT_RG_CENTER) ) {
1758                             stop = sp_first_stop(vector);
1759                         } else {
1760                             stop = sp_last_stop(vector);
1761                         }
1762                         if (stop) {
1763                             StructStopInfo *stopinfo = new StructStopInfo;
1764                             stopinfo->spstop = stop;
1765                             stopinfo->draggable = draggable;
1766                             stopinfo->gradient = gradient;
1767                             stopinfo->vector = vector;
1768                             // check if already present in list. (e.g. when both R1 and R2 were selected)
1769                             bool present = false;
1770                             for (GSList const * l = endstoplist; l != NULL; l = l->next) {
1771                                 if ( ((StructStopInfo*)l->data)->spstop == stopinfo->spstop ) {
1772                                     present = true;
1773                                     break; // no need to search further.
1774                                 }
1775                             }
1776                             if (!present)
1777                                 endstoplist = g_slist_append(endstoplist, stopinfo);
1778                         }
1779                     }
1780                     break;
1781                 default:
1782                     break;
1783             }
1784         }
1785         selected = g_list_remove(selected, dragger);
1786         if ( just_one ) break; // iterate once if just_one is set.
1787     }
1788     while (midstoplist) {
1789         SPStop *stop = (SPStop*) midstoplist->data;
1790         document = SP_OBJECT_DOCUMENT (stop);
1791         Inkscape::XML::Node * parent = SP_OBJECT_REPR(stop)->parent();
1792         parent->removeChild(SP_OBJECT_REPR(stop));
1793         midstoplist = g_slist_remove(midstoplist, stop);
1794     }
1795     while (endstoplist) {
1796         StructStopInfo *stopinfo  = (StructStopInfo*) endstoplist->data;
1797         document = SP_OBJECT_DOCUMENT (stopinfo->spstop);
1798
1799         // 2 is the minimum, cannot delete more than that without deleting the whole vector
1800         // cannot use vector->vector.stops.size() because the vector might be invalidated by deletion of a midstop
1801         // manually count the children, don't know if there already exists a function for this...
1802         int len = 0;
1803         for ( SPObject *child = sp_object_first_child(stopinfo->vector) ;
1804               child != NULL ;
1805               child = SP_OBJECT_NEXT(child) )
1806         {
1807             if ( SP_IS_STOP(child) )  len ++;
1808         }
1809         if (len > 2)
1810         {
1811             switch (stopinfo->draggable->point_type) {
1812                 case POINT_LG_BEGIN:
1813                     {
1814                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1815
1816                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
1817                         NR::Point oldbegin = NR::Point (lg->x1.computed, lg->y1.computed);
1818                         NR::Point end = NR::Point (lg->x2.computed, lg->y2.computed);
1819                         SPStop *stop = sp_first_stop(stopinfo->vector);
1820                         gdouble offset = stop->offset;
1821                         NR::Point newbegin = oldbegin + offset * (end - oldbegin);
1822                         lg->x1.computed = newbegin[NR::X];
1823                         lg->y1.computed = newbegin[NR::Y];
1824
1825                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
1826                         sp_repr_set_svg_double(repr, "x1", lg->x1.computed);
1827                         sp_repr_set_svg_double(repr, "y1", lg->y1.computed);
1828                         stop->offset = 0;
1829                         sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", 0);
1830
1831                         // iterate through midstops to set new offset values such that they won't move on canvas.
1832                         SPStop *laststop = sp_last_stop(stopinfo->vector);
1833                         stop = sp_next_stop(stop);
1834                         while ( stop != laststop ) {
1835                             stop->offset = (stop->offset - offset)/(1 - offset);
1836                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
1837                             stop = sp_next_stop(stop);
1838                         }
1839                     }
1840                     break;
1841                 case POINT_LG_END:
1842                     {
1843                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1844
1845                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
1846                         NR::Point begin = NR::Point (lg->x1.computed, lg->y1.computed);
1847                         NR::Point oldend = NR::Point (lg->x2.computed, lg->y2.computed);
1848                         SPStop *laststop = sp_last_stop(stopinfo->vector);
1849                         gdouble offset = laststop->offset;
1850                         NR::Point newend = begin + offset * (oldend - begin);
1851                         lg->x2.computed = newend[NR::X];
1852                         lg->y2.computed = newend[NR::Y];
1853
1854                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
1855                         sp_repr_set_svg_double(repr, "x2", lg->x2.computed);
1856                         sp_repr_set_svg_double(repr, "y2", lg->y2.computed);
1857                         laststop->offset = 1;
1858                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
1859
1860                         // iterate through midstops to set new offset values such that they won't move on canvas.
1861                         SPStop *stop = sp_first_stop(stopinfo->vector);
1862                         stop = sp_next_stop(stop);
1863                         while ( stop != laststop ) {
1864                             stop->offset = stop->offset / offset;
1865                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
1866                             stop = sp_next_stop(stop);
1867                         }
1868                     }
1869                     break;
1870                 case POINT_RG_CENTER:
1871                     {
1872                         SPStop *newfirst = sp_next_stop (stopinfo->spstop);
1873                         if (newfirst) {
1874                             newfirst->offset = 0;
1875                             sp_repr_set_css_double (SP_OBJECT_REPR (newfirst), "offset", 0);
1876                         }
1877                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1878                     }
1879                     break;
1880                 case POINT_RG_R1:
1881                 case POINT_RG_R2:
1882                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1883
1884                         SPRadialGradient *rg = SP_RADIALGRADIENT(stopinfo->gradient);
1885                         double oldradius = rg->r.computed;
1886                         SPStop *laststop = sp_last_stop(stopinfo->vector);
1887                         gdouble offset = laststop->offset;
1888                         double newradius = offset * oldradius;
1889                         rg->r.computed = newradius;
1890
1891                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(rg);
1892                         sp_repr_set_svg_double(repr, "r", rg->r.computed);
1893                         laststop->offset = 1;
1894                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
1895
1896                         // iterate through midstops to set new offset values such that they won't move on canvas.
1897                         SPStop *stop = sp_first_stop(stopinfo->vector);
1898                         stop = sp_next_stop(stop);
1899                         while ( stop != laststop ) {
1900                             stop->offset = stop->offset / offset;
1901                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
1902                             stop = sp_next_stop(stop);
1903                         }
1904                         break;
1905             }
1906         }
1907         else
1908         { // delete the gradient from the object. set fill to unset  FIXME: set to fill of unselected node?
1909             SPCSSAttr *css = sp_repr_css_attr_new ();
1910
1911             // stopinfo->spstop is the selected stop
1912             Inkscape::XML::Node *unselectedrepr = SP_OBJECT_REPR(stopinfo->vector)->firstChild();
1913             if (unselectedrepr == SP_OBJECT_REPR(stopinfo->spstop) ) {
1914                 unselectedrepr = unselectedrepr->next();
1915             }
1916
1917             if (unselectedrepr == NULL) {
1918                 if (stopinfo->draggable->fill_or_stroke) {
1919                     sp_repr_css_unset_property (css, "fill");
1920                 } else {
1921                     sp_repr_css_unset_property (css, "stroke");
1922                 }
1923             } else {
1924                 SPCSSAttr *stopcss = sp_repr_css_attr(unselectedrepr, "style");
1925                 if (stopinfo->draggable->fill_or_stroke) {
1926                     sp_repr_css_set_property(css, "fill", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
1927                     sp_repr_css_set_property(css, "fill-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
1928                 } else {
1929                     sp_repr_css_set_property(css, "stroke", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
1930                     sp_repr_css_set_property(css, "stroke-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
1931                 }
1932                 sp_repr_css_attr_unref (stopcss);
1933             }
1934
1935             sp_repr_css_change (SP_OBJECT_REPR (stopinfo->draggable->item), css, "style");
1936             sp_repr_css_attr_unref (css);
1937         }
1938
1939         endstoplist = g_slist_remove(endstoplist, stopinfo);
1940         delete stopinfo;
1941     }
1942
1943     if (document) {
1944         sp_document_done ( document, SP_VERB_CONTEXT_GRADIENT, _("Delete gradient stop(s)") );
1945     }
1946 }
1947
1948
1949 /*
1950   Local Variables:
1951   mode:c++
1952   c-file-style:"stroustrup"
1953   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1954   indent-tabs-mode:nil
1955   fill-column:99
1956   End:
1957 */
1958 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :