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 (GList *i = drag->selected; i != NULL; i = i->next) { // for all selected draggers
 132             GrDragger *d = (GrDragger *) i->data;
 133             for (GSList const* j = d->draggables; j != NULL; j = j->next) { // for all draggables of dragger
 134                 GrDraggable *draggable = (GrDraggable *) j->data;
 135
 136                 if (ret == QUERY_STYLE_NOTHING) {
 137                     ret = QUERY_STYLE_SINGLE;
 138                 } else if (ret == QUERY_STYLE_SINGLE) {
 139                     ret = QUERY_STYLE_MULTIPLE_AVERAGED;
 140                 }
 141
 142                 guint32 c = sp_item_gradient_stop_query_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 143                 cf[0] += SP_RGBA32_R_F (c);
 144                 cf[1] += SP_RGBA32_G_F (c);
 145                 cf[2] += SP_RGBA32_B_F (c);
 146                 cf[3] += SP_RGBA32_A_F (c);
 147
 148                 count ++;
 149             }
 150         }
 151
 152         if (count) {
 153             cf[0] /= count;
 154             cf[1] /= count;
 155             cf[2] /= count;
 156             cf[3] /= count;
 157
 158             // set both fill and stroke with our stop-color and stop-opacity
 159             style->fill.clear();
 160             style->fill.setColor( cf[0], cf[1], cf[2] );
 161             style->fill.set = TRUE;
 162             style->stroke.clear();
 163             style->stroke.setColor( cf[0], cf[1], cf[2] );
 164             style->stroke.set = TRUE;
 165
 166             style->fill_opacity.value = SP_SCALE24_FROM_FLOAT (1.0);
 167             style->fill_opacity.set = TRUE;
 168             style->stroke_opacity.value = SP_SCALE24_FROM_FLOAT (1.0);
 169             style->stroke_opacity.set = TRUE;
 170
 171             style->opacity.value = SP_SCALE24_FROM_FLOAT (cf[3]);
 172             style->opacity.set = TRUE;
 173         }
 174
 175         return ret;
 176     }
 177 }
 178
 179 bool
 180 gr_drag_style_set (const SPCSSAttr *css, gpointer data)
 181 {
 182     GrDrag *drag = (GrDrag *) data;
 183
 184     if (!drag->selected)
 185         return false;
 186
 187     SPCSSAttr *stop = sp_repr_css_attr_new ();
 188
 189     // See if the css contains interesting properties, and if so, translate them into the format
 190     // acceptable for gradient stops
 191
 192     // any of color properties, in order of increasing priority:
 193     if (css->attribute("flood-color"))
 194         sp_repr_css_set_property (stop, "stop-color", css->attribute("flood-color"));
 195
 196     if (css->attribute("lighting-color"))
 197         sp_repr_css_set_property (stop, "stop-color", css->attribute("lighting-color"));
 198
 199     if (css->attribute("color"))
 200         sp_repr_css_set_property (stop, "stop-color", css->attribute("color"));
 201
 202     if (css->attribute("stroke") && strcmp(css->attribute("stroke"), "none"))
 203         sp_repr_css_set_property (stop, "stop-color", css->attribute("stroke"));
 204
 205     if (css->attribute("fill") && strcmp(css->attribute("fill"), "none"))
 206         sp_repr_css_set_property (stop, "stop-color", css->attribute("fill"));
 207
 208     if (css->attribute("stop-color"))
 209         sp_repr_css_set_property (stop, "stop-color", css->attribute("stop-color"));
 210
 211
 212     if (css->attribute("stop-opacity")) { // direct setting of stop-opacity has priority
 213         sp_repr_css_set_property (stop, "stop-opacity", css->attribute("stop-opacity"));
 214     } else {  // multiply all opacity properties:
 215         gdouble accumulated = 1.0;
 216         accumulated *= sp_svg_read_percentage(css->attribute("flood-opacity"), 1.0);
 217         accumulated *= sp_svg_read_percentage(css->attribute("opacity"), 1.0);
 218         accumulated *= sp_svg_read_percentage(css->attribute("stroke-opacity"), 1.0);
 219         accumulated *= sp_svg_read_percentage(css->attribute("fill-opacity"), 1.0);
 220
 221         Inkscape::CSSOStringStream os;
 222         os << accumulated;
 223         sp_repr_css_set_property (stop, "stop-opacity", os.str().c_str());
 224
 225         if ((css->attribute("fill") && !strcmp(css->attribute("fill"), "none")) ||
 226             (css->attribute("stroke") && !strcmp(css->attribute("stroke"), "none")))
 227             sp_repr_css_set_property (stop, "stop-opacity", "0"); // if set to none, don't change color, set opacity to 0
 228     }
 229
 230     if (!stop->attributeList()) { // nothing for us here, pass it on
 231         sp_repr_css_attr_unref(stop);
 232         return false;
 233     }
 234
 235     for (GList const* sel = drag->selected; sel != NULL; sel = sel->next) { // for all selected draggers
 236         GrDragger* dragger = (GrDragger*) sel->data;
 237         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 238                GrDraggable *draggable = (GrDraggable *) i->data;
 239
 240                drag->local_change = true;
 241                sp_item_gradient_stop_set_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke, stop);
 242         }
 243     }
 244
 245     //sp_repr_css_print(stop);
 246     sp_repr_css_attr_unref(stop);
 247     return true;
 248 }
 249
 250 GrDrag::GrDrag(SPDesktop *desktop) {
 251
 252     this->desktop = desktop;
 253
 254     this->selection = sp_desktop_selection(desktop);
 255
 256     this->draggers = NULL;
 257     this->lines = NULL;
 258     this->selected = NULL;
 259
 260     this->hor_levels.clear();
 261     this->vert_levels.clear();
 262
 263     this->local_change = false;
 264
 265     this->sel_changed_connection = this->selection->connectChanged(
 266         sigc::bind (
 267             sigc::ptr_fun(&gr_drag_sel_changed),
 268             (gpointer)this )
 269
 270         );
 271     this->sel_modified_connection = this->selection->connectModified(
 272         sigc::bind(
 273             sigc::ptr_fun(&gr_drag_sel_modified),
 274             (gpointer)this )
 275         );
 276
 277     this->style_set_connection = this->desktop->connectSetStyle(
 278         sigc::bind(
 279             sigc::ptr_fun(&gr_drag_style_set),
 280             (gpointer)this )
 281         );
 282
 283     this->style_query_connection = this->desktop->connectQueryStyle(
 284         sigc::bind(
 285             sigc::ptr_fun(&gr_drag_style_query),
 286             (gpointer)this )
 287         );
 288
 289     this->updateDraggers ();
 290     this->updateLines ();
 291     this->updateLevels ();
 292
 293     if (desktop->gr_item) {
 294         this->setSelected (getDraggerFor (desktop->gr_item, desktop->gr_point_type, desktop->gr_point_i, desktop->gr_fill_or_stroke));
 295     }
 296 }
 297
 298 GrDrag::~GrDrag()
 299 {
 300     this->sel_changed_connection.disconnect();
 301     this->sel_modified_connection.disconnect();
 302     this->style_set_connection.disconnect();
 303     this->style_query_connection.disconnect();
 304
 305     if (this->selected) {
 306         GrDraggable *draggable = (GrDraggable *)   ((GrDragger*)this->selected->data)->draggables->data;
 307         desktop->gr_item = draggable->item;
 308         desktop->gr_point_type = draggable->point_type;
 309         desktop->gr_point_i = draggable->point_i;
 310         desktop->gr_fill_or_stroke = draggable->fill_or_stroke;
 311     } else {
 312         desktop->gr_item = NULL;
 313         desktop->gr_point_type = 0;
 314         desktop->gr_point_i = 0;
 315         desktop->gr_fill_or_stroke = true;
 316     }
 317
 318     deselect_all();
 319     for (GList *l = this->draggers; l != NULL; l = l->next) {
 320         delete ((GrDragger *) l->data);
 321     }
 322     g_list_free (this->draggers);
 323     this->draggers = NULL;
 324     this->selected = NULL;
 325
 326     for (GSList *l = this->lines; l != NULL; l = l->next) {
 327         gtk_object_destroy( GTK_OBJECT (l->data));
 328     }
 329     g_slist_free (this->lines);
 330     this->lines = NULL;
 331 }
 332
 333 GrDraggable::GrDraggable (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke)
 334 {
 335     this->item = item;
 336     this->point_type = point_type;
 337     this->point_i = point_i;
 338     this->fill_or_stroke = fill_or_stroke;
 339
 340     g_object_ref (G_OBJECT (this->item));
 341 }
 342
 343 GrDraggable::~GrDraggable ()
 344 {
 345     g_object_unref (G_OBJECT (this->item));
 346 }
 347
 348
 349 SPObject *
 350 GrDraggable::getServer ()
 351 {
 352     if (!item)
 353         return NULL;
 354
 355     SPObject *server = NULL;
 356     if (fill_or_stroke)
 357         server = SP_OBJECT_STYLE_FILL_SERVER (item);
 358     else
 359         server = SP_OBJECT_STYLE_STROKE_SERVER (item);
 360
 361     return server;
 362 }
 363
 364
 365 // FIXME: make global function in libnr or somewhere.
 366 static NR::Point *
 367 get_snap_vector (NR::Point p, NR::Point o, double snap, double initial)
 368 {
 369     double r = NR::L2 (p - o);
 370     if (r < 1e-3)
 371         return NULL;
 372     double angle = NR::atan2 (p - o);
 373     // snap angle to snaps increments, starting from initial:
 374     double a_snapped = initial + floor((angle - initial)/snap + 0.5) * snap;
 375     // calculate the new position and subtract p to get the vector:
 376     return new NR::Point (o + r * NR::Point(cos(a_snapped), sin(a_snapped)) - p);
 377 }
 378
 379 // FIXME: make global function in libnr or somewhere.
 380 static NR::Point
 381 snap_vector_midpoint (NR::Point p, NR::Point begin, NR::Point end, double snap)
 382 {
 383     double length = NR::L2(end - begin);
 384     NR::Point be = (end - begin) / length;
 385     double r = NR::dot(p - begin, be);
 386
 387     if (r < 0.0) return begin;
 388     if (r > length) return end;
 389
 390     double snapdist = length * snap;
 391     double r_snapped = (snap==0) ? r : floor(r/(snapdist + 0.5)) * snapdist;
 392
 393     return (begin + r_snapped * be);
 394 }
 395
 396 static void
 397 gr_knot_moved_handler(SPKnot *knot, NR::Point const *ppointer, guint state, gpointer data)
 398 {
 399     GrDragger *dragger = (GrDragger *) data;
 400     GrDrag *drag = dragger->parent;
 401
 402     NR::Point p = *ppointer;
 403
 404     // FIXME: take from prefs
 405     double snap_dist = SNAP_DIST / dragger->parent->desktop->current_zoom();
 406
 407     if (state & GDK_SHIFT_MASK) {
 408         // with Shift; unsnap if we carry more than one draggable
 409         if (dragger->draggables && dragger->draggables->next) {
 410             // create a new dragger
 411             GrDragger *dr_new = new GrDragger (dragger->parent, dragger->point, NULL);
 412             dragger->parent->draggers = g_list_prepend (dragger->parent->draggers, dr_new);
 413             // relink to it all but the first draggable in the list
 414             for (GSList const* i = dragger->draggables->next; i != NULL; i = i->next) {
 415                 GrDraggable *draggable = (GrDraggable *) i->data;
 416                 dr_new->addDraggable (draggable);
 417             }
 418             dr_new->updateKnotShape();
 419             g_slist_free (dragger->draggables->next);
 420             dragger->draggables->next = NULL;
 421             dragger->updateKnotShape();
 422             dragger->updateTip();
 423         }
 424     } else if (!(state & GDK_CONTROL_MASK)) {
 425         // without Shift or Ctrl; see if we need to snap to another dragger
 426         for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 427             GrDragger *d_new = (GrDragger *) di->data;
 428             if (dragger->mayMerge(d_new) && NR::L2 (d_new->point - p) < snap_dist) {
 429
 430                 // Merge draggers:
 431                 for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 432                     GrDraggable *draggable = (GrDraggable *) i->data;
 433                     // copy draggable to d_new:
 434                     GrDraggable *da_new = new GrDraggable (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 435                     d_new->addDraggable (da_new);
 436                 }
 437
 438                 // unlink and delete this dragger
 439                 dragger->parent->draggers = g_list_remove (dragger->parent->draggers, dragger);
 440                 delete dragger;
 441
 442                 // update the new merged dragger
 443                 d_new->fireDraggables(true, false, true);
 444                 d_new->parent->updateLines();
 445                 d_new->parent->setSelected (d_new);
 446                 d_new->updateKnotShape ();
 447                 d_new->updateTip ();
 448                 d_new->updateDependencies(true);
 449                 sp_document_done (sp_desktop_document (d_new->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 450                                   _("Merge gradient handles"));
 451                 return;
 452             }
 453         }
 454     }
 455
 456     if (!((state & GDK_SHIFT_MASK) || ((state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK)))) {
 457         // Try snapping to the grid or guides
 458         SnapManager const &m = dragger->parent->desktop->namedview->snap_manager;
 459         Inkscape::SnappedPoint s = m.freeSnap(Inkscape::Snapper::SNAPPOINT_NODE, p, NULL);
 460         if (s.getDistance() < 1e6) {
 461             p = s.getPoint();
 462             sp_knot_moveto (knot, &p);
 463         } else {
 464             // No snapping so far, let's see if we need to snap to any of the levels
 465             for (guint i = 0; i < dragger->parent->hor_levels.size(); i++) {
 466                 if (fabs(p[NR::Y] - dragger->parent->hor_levels[i]) < snap_dist) {
 467                     p[NR::Y] = dragger->parent->hor_levels[i];
 468                     sp_knot_moveto (knot, &p);
 469                 }
 470             }
 471             for (guint i = 0; i < dragger->parent->vert_levels.size(); i++) {
 472                 if (fabs(p[NR::X] - dragger->parent->vert_levels[i]) < snap_dist) {
 473                     p[NR::X] = dragger->parent->vert_levels[i];
 474                     sp_knot_moveto (knot, &p);
 475                 }
 476             }
 477         }
 478     }
 479
 480     if (state & GDK_CONTROL_MASK) {
 481         unsigned snaps = abs(prefs_get_int_attribute("options.rotationsnapsperpi", "value", 12));
 482         /* 0 means no snapping. */
 483
 484         // This list will store snap vectors from all draggables of dragger
 485         GSList *snap_vectors = NULL;
 486
 487         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) {
 488             GrDraggable *draggable = (GrDraggable *) i->data;
 489
 490             NR::Point *dr_snap = NULL;
 491
 492             if (draggable->point_type == POINT_LG_BEGIN || draggable->point_type == POINT_LG_END) {
 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                                     draggable->point_type == POINT_LG_BEGIN? POINT_LG_END : POINT_LG_BEGIN,
 499                                     draggable->point_i,
 500                                     draggable->fill_or_stroke)) {
 501                         // found the other end of the linear gradient;
 502                         if (state & GDK_SHIFT_MASK) {
 503                             // moving linear around center
 504                             NR::Point center = NR::Point (0.5*(d_new->point + dragger->point));
 505                             dr_snap = &center;
 506                         } else {
 507                             // moving linear around the other end
 508                             dr_snap = &d_new->point;
 509                         }
 510                     }
 511                 }
 512             } else if (draggable->point_type == POINT_RG_R1 || draggable->point_type == POINT_RG_R2 || draggable->point_type == POINT_RG_FOCUS) {
 513                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 514                     GrDragger *d_new = (GrDragger *) di->data;
 515                     if (d_new == dragger)
 516                         continue;
 517                     if (d_new->isA (draggable->item,
 518                                     POINT_RG_CENTER,
 519                                     draggable->point_i,
 520                                     draggable->fill_or_stroke)) {
 521                         // found the center of the radial gradient;
 522                         dr_snap = &(d_new->point);
 523                     }
 524                 }
 525             } else if (draggable->point_type == POINT_RG_CENTER) {
 526                 // radial center snaps to hor/vert relative to its original position
 527                 dr_snap = &(dragger->point_original);
 528             }
 529
 530             NR::Point *snap_vector = NULL;
 531             if (dr_snap) {
 532                 if (state & GDK_MOD1_MASK) {
 533                     // with Alt, snap to the original angle and its perpendiculars
 534                     snap_vector = get_snap_vector (p, *dr_snap, M_PI/2, NR::atan2 (dragger->point_original - *dr_snap));
 535                 } else {
 536                     // with Ctrl, snap to M_PI/snaps
 537                     snap_vector = get_snap_vector (p, *dr_snap, M_PI/snaps, 0);
 538                 }
 539             }
 540             if (snap_vector) {
 541                 snap_vectors = g_slist_prepend (snap_vectors, snap_vector);
 542             }
 543         }
 544
 545         // Move by the smallest of snap vectors:
 546         NR::Point move(9999, 9999);
 547         for (GSList const *i = snap_vectors; i != NULL; i = i->next) {
 548             NR::Point *snap_vector = (NR::Point *) i->data;
 549             if (NR::L2(*snap_vector) < NR::L2(move))
 550                 move = *snap_vector;
 551         }
 552         if (move[NR::X] < 9999) {
 553             p += move;
 554             sp_knot_moveto (knot, &p);
 555         }
 556
 557         g_slist_free(snap_vectors);
 558     }
 559
 560     drag->keep_selection = (bool) g_list_find(drag->selected, dragger);
 561     bool scale_radial = (state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK);
 562
 563     if (drag->keep_selection) {
 564         NR::Point diff = p - dragger->point;
 565         drag->selected_move_nowrite (diff[NR::X], diff[NR::Y], scale_radial);
 566     } else {
 567         dragger->point = p;
 568         dragger->fireDraggables (false, scale_radial);
 569         dragger->updateDependencies(false);
 570     }
 571
 572 }
 573
 574
 575 static void
 576 gr_midpoint_limits(GrDragger *dragger, SPObject *server, NR::Point *begin, NR::Point *end, NR::Point *low_lim, NR::Point *high_lim, GSList **moving)
 577 {
 578
 579     GrDrag *drag = dragger->parent;
 580     // a midpoint dragger can (logically) only contain one GrDraggable
 581     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 582
 583     // get begin and end points between which dragging is allowed:
 584     // the draglimits are between knot(lowest_i - 1) and knot(highest_i + 1)
 585     *moving = g_slist_append(*moving, dragger);
 586
 587     guint lowest_i = draggable->point_i;
 588     guint highest_i = draggable->point_i;
 589     GrDragger *lowest_dragger = dragger;
 590     GrDragger *highest_dragger = dragger;
 591     if (dragger->isSelected()) {
 592         GrDragger* d_add;
 593         while ( true )
 594         {
 595             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 596             if ( d_add && g_list_find(drag->selected, d_add) ) {
 597                 lowest_i = lowest_i - 1;
 598                 *moving = g_slist_prepend(*moving, d_add);
 599                 lowest_dragger = d_add;
 600             } else {
 601                 break;
 602             }
 603         }
 604
 605         while ( true )
 606         {
 607             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 608             if ( d_add && g_list_find(drag->selected, d_add) ) {
 609                 highest_i = highest_i + 1;
 610                 *moving = g_slist_append(*moving, d_add);
 611                 highest_dragger = d_add;
 612             } else {
 613                 break;
 614             }
 615         }
 616     }
 617
 618     if ( SP_IS_LINEARGRADIENT(server) ) {
 619         guint num = SP_LINEARGRADIENT(server)->vector.stops.size();
 620         GrDragger *d_temp;
 621         if (lowest_i == 1) {
 622             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke);
 623         } else {
 624             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, lowest_i - 1, draggable->fill_or_stroke);
 625         }
 626         if (d_temp)
 627             *begin = d_temp->point;
 628
 629         d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, highest_i + 1, draggable->fill_or_stroke);
 630         if (d_temp == NULL) {
 631             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_END, num-1, draggable->fill_or_stroke);
 632         }
 633         if (d_temp)
 634             *end = d_temp->point;
 635     } else if ( SP_IS_RADIALGRADIENT(server) ) {
 636         guint num = SP_RADIALGRADIENT(server)->vector.stops.size();
 637         GrDragger *d_temp;
 638         if (lowest_i == 1) {
 639             d_temp = drag->getDraggerFor (draggable->item, POINT_RG_CENTER, 0, draggable->fill_or_stroke);
 640         } else {
 641             d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 642         }
 643         if (d_temp)
 644             *begin = d_temp->point;
 645
 646         d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 647         if (d_temp == NULL) {
 648             d_temp = drag->getDraggerFor (draggable->item, (draggable->point_type==POINT_RG_MID1) ? POINT_RG_R1 : POINT_RG_R2, num-1, draggable->fill_or_stroke);
 649         }
 650         if (d_temp)
 651             *end = d_temp->point;
 652     }
 653
 654     *low_lim  = dragger->point - (lowest_dragger->point - *begin);
 655     *high_lim = dragger->point - (highest_dragger->point - *end);
 656 }
 657
 658
 659
 660 /**
 661 Called when a midpoint knot is dragged.
 662 */
 663 static void
 664 gr_knot_moved_midpoint_handler(SPKnot *knot, NR::Point const *ppointer, guint state, gpointer data)
 665 {
 666     GrDragger *dragger = (GrDragger *) data;
 667     GrDrag *drag = dragger->parent;
 668     // a midpoint dragger can (logically) only contain one GrDraggable
 669     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 670
 671     // FIXME: take from prefs
 672     double snap_fraction = 0.1;
 673
 674     NR::Point p = *ppointer;
 675     NR::Point begin(0,0), end(0,0);
 676     NR::Point low_lim(0,0), high_lim(0,0);
 677
 678     SPObject *server = draggable->getServer();
 679
 680     GSList *moving = NULL;
 681     gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
 682
 683     if (state & GDK_CONTROL_MASK) {
 684         p = snap_vector_midpoint (p, low_lim, high_lim, snap_fraction);
 685     } else {
 686         p = snap_vector_midpoint (p, low_lim, high_lim, 0);
 687     }
 688     NR::Point displacement = p - dragger->point;
 689
 690     for (GSList const* i = moving; i != NULL; i = i->next) {
 691         GrDragger *drg = (GrDragger*) i->data;
 692         SPKnot *drgknot = drg->knot;
 693         NR::Point this_move = displacement;
 694         if (state & GDK_MOD1_MASK) {
 695             // FIXME: unify all these profiles (here, in nodepath, in tweak) in one place
 696             double alpha = 1.5;
 697             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
 698                 double x = NR::L2(drg->point - dragger->point)/NR::L2(end - dragger->point);
 699                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 700             } else { // drg is on the begin side from dragger
 701                 double x = NR::L2(drg->point - dragger->point)/NR::L2(begin - dragger->point);
 702                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 703             }
 704         }
 705         drg->point += this_move;
 706         sp_knot_moveto (drgknot, & drg->point);
 707         drg->fireDraggables (false);
 708         drg->updateDependencies(false);
 709     }
 710
 711     g_slist_free(moving);
 712
 713     drag->keep_selection = dragger->isSelected();
 714 }
 715
 716
 717
 718 static void
 719 gr_knot_grabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 720 {
 721     GrDragger *dragger = (GrDragger *) data;
 722
 723     sp_canvas_force_full_redraw_after_interruptions(dragger->parent->desktop->canvas, 5);
 724 }
 725
 726 /**
 727 Called when the mouse releases a dragger knot; changes gradient writing to repr, updates other draggers if needed
 728 */
 729 static void
 730 gr_knot_ungrabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 731 {
 732     GrDragger *dragger = (GrDragger *) data;
 733
 734     sp_canvas_end_forced_full_redraws(dragger->parent->desktop->canvas);
 735
 736     dragger->point_original = dragger->point = knot->pos;
 737
 738     if ((state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK)) {
 739         dragger->fireDraggables (true, true);
 740     } else {
 741         dragger->fireDraggables (true);
 742     }
 743
 744     for (GList *i = dragger->parent->selected; i != NULL; i = i->next) {
 745         GrDragger *d = (GrDragger *) i->data;
 746         if (d == dragger)
 747             continue;
 748         d->fireDraggables (true);
 749     }
 750
 751     // make this dragger selected
 752     if (!dragger->parent->keep_selection) {
 753         dragger->parent->setSelected (dragger);
 754     }
 755     dragger->parent->keep_selection = false;
 756
 757     dragger->updateDependencies(true);
 758
 759     // we did an undoable action
 760     sp_document_done (sp_desktop_document (dragger->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 761                       _("Move gradient handle"));
 762 }
 763
 764 /**
 765 Called when a dragger knot is clicked; selects the dragger or deletes it depending on the
 766 state of the keyboard keys
 767 */
 768 static void
 769 gr_knot_clicked_handler(SPKnot *knot, guint state, gpointer data)
 770 {
 771     GrDragger *dragger = (GrDragger *) data;
 772     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 773     if (!draggable) return;
 774
 775     if ( (state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK ) ) {
 776     // delete this knot from vector
 777         SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
 778         gradient = sp_gradient_get_vector (gradient, false);
 779         if (gradient->vector.stops.size() > 2) { // 2 is the minimum
 780                 SPStop *stop = NULL;
 781                 switch (draggable->point_type) {  // if we delete first or last stop, move the next/previous to the edge
 782                 case POINT_LG_BEGIN:
 783                 case POINT_RG_CENTER:
 784                     stop = sp_first_stop(gradient);
 785                         {
 786                             SPStop *next = sp_next_stop (stop);
 787                                 if (next) {
 788                                         next->offset = 0;
 789                                         sp_repr_set_css_double (SP_OBJECT_REPR (next), "offset", 0);
 790                                 }
 791                         }
 792                     break;
 793                 case POINT_LG_END:
 794                 case POINT_RG_R1:
 795                 case POINT_RG_R2:
 796                     stop = sp_last_stop(gradient);
 797                     {
 798                             SPStop *prev = sp_prev_stop (stop, gradient);
 799                             if (prev) {
 800                                     prev->offset = 1;
 801                                     sp_repr_set_css_double (SP_OBJECT_REPR (prev), "offset", 1);
 802                             }
 803                         }
 804                     break;
 805                 case POINT_LG_MID:
 806                 case POINT_RG_MID1:
 807                 case POINT_RG_MID2:
 808                     stop = sp_get_stop_i(gradient, draggable->point_i);
 809                     break;
 810                 }
 811
 812                 SP_OBJECT_REPR(gradient)->removeChild(SP_OBJECT_REPR(stop));
 813                 sp_document_done (SP_OBJECT_DOCUMENT (gradient), SP_VERB_CONTEXT_GRADIENT,
 814                                   _("Delete gradient stop"));
 815         }
 816     } else {
 817     // select the dragger
 818         dragger->point_original = dragger->point;
 819
 820         if ( state & GDK_SHIFT_MASK ) {
 821             dragger->parent->setSelected (dragger, true, false);
 822         } else {
 823             dragger->parent->setSelected (dragger);
 824         }
 825     }
 826 }
 827
 828 /**
 829 Called when a dragger knot is doubleclicked; opens gradient editor with the stop from the first draggable
 830 */
 831 static void
 832 gr_knot_doubleclicked_handler (SPKnot *knot, guint state, gpointer data)
 833 {
 834     GrDragger *dragger = (GrDragger *) data;
 835
 836     dragger->point_original = dragger->point;
 837
 838     if (dragger->draggables == NULL)
 839         return;
 840
 841     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 842     sp_item_gradient_edit_stop (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 843 }
 844
 845 /**
 846 Act upon all draggables of the dragger, setting them to the dragger's point
 847 */
 848 void
 849 GrDragger::fireDraggables (bool write_repr, bool scale_radial, bool merging_focus)
 850 {
 851     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 852         GrDraggable *draggable = (GrDraggable *) i->data;
 853
 854         // set local_change flag so that selection_changed callback does not regenerate draggers
 855         this->parent->local_change = true;
 856
 857         // change gradient, optionally writing to repr; prevent focus from moving if it's snapped
 858         // to the center, unless it's the first update upon merge when we must snap it to the point
 859         if (merging_focus ||
 860             !(draggable->point_type == POINT_RG_FOCUS && this->isA(draggable->item, POINT_RG_CENTER, draggable->point_i, draggable->fill_or_stroke)))
 861         {
 862             sp_item_gradient_set_coords (draggable->item, draggable->point_type, draggable->point_i, this->point, draggable->fill_or_stroke, write_repr, scale_radial);
 863         }
 864     }
 865 }
 866
 867 /**
 868 Checks if the dragger has a draggable with this point_type
 869  */
 870 bool
 871 GrDragger::isA (gint point_type)
 872 {
 873     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 874         GrDraggable *draggable = (GrDraggable *) i->data;
 875         if (draggable->point_type == point_type) {
 876             return true;
 877         }
 878     }
 879     return false;
 880 }
 881
 882 /**
 883 Checks if the dragger has a draggable with this item, point_type, fill_or_stroke
 884  */
 885 bool
 886 GrDragger::isA (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
 887 {
 888     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 889         GrDraggable *draggable = (GrDraggable *) i->data;
 890         if ( (draggable->point_type == point_type) && (draggable->point_i == point_i) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
 891             return true;
 892         }
 893     }
 894     return false;
 895 }
 896
 897 bool
 898 GrDraggable::mayMerge (GrDraggable *da2)
 899 {
 900     if ((this->item == da2->item) && (this->fill_or_stroke == da2->fill_or_stroke)) {
 901         // we must not merge the points of the same gradient!
 902         if (!((this->point_type == POINT_RG_FOCUS && da2->point_type == POINT_RG_CENTER) ||
 903               (this->point_type == POINT_RG_CENTER && da2->point_type == POINT_RG_FOCUS))) {
 904             // except that we can snap center and focus together
 905             return false;
 906         }
 907     }
 908     // disable merging of midpoints.
 909     if ( (this->point_type == POINT_LG_MID) || (da2->point_type == POINT_LG_MID)
 910          || (this->point_type == POINT_RG_MID1) || (da2->point_type == POINT_RG_MID1)
 911          || (this->point_type == POINT_RG_MID2) || (da2->point_type == POINT_RG_MID2) )
 912         return false;
 913
 914     return true;
 915 }
 916
 917 bool
 918 GrDragger::mayMerge (GrDragger *other)
 919 {
 920     if (this == other)
 921         return false;
 922
 923     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
 924         GrDraggable *da1 = (GrDraggable *) i->data;
 925         for (GSList const* j = other->draggables; j != NULL; j = j->next) { // for all draggables of other
 926             GrDraggable *da2 = (GrDraggable *) j->data;
 927             if (!da1->mayMerge(da2))
 928                 return false;
 929         }
 930     }
 931     return true;
 932 }
 933
 934 bool
 935 GrDragger::mayMerge (GrDraggable *da2)
 936 {
 937     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
 938         GrDraggable *da1 = (GrDraggable *) i->data;
 939         if (!da1->mayMerge(da2))
 940             return false;
 941     }
 942     return true;
 943 }
 944
 945 /**
 946 Updates the statusbar tip of the dragger knot, based on its draggables
 947  */
 948 void
 949 GrDragger::updateTip ()
 950 {
 951         if (this->knot && this->knot->tip) {
 952                 g_free (this->knot->tip);
 953                 this->knot->tip = NULL;
 954         }
 955
 956     if (g_slist_length (this->draggables) == 1) {
 957         GrDraggable *draggable = (GrDraggable *) this->draggables->data;
 958         char *item_desc = sp_item_description(draggable->item);
 959         switch (draggable->point_type) {
 960             case POINT_LG_MID:
 961             case POINT_RG_MID1:
 962             case POINT_RG_MID2:
 963                 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"),
 964                                                    _(gr_knot_descr[draggable->point_type]),
 965                                                    draggable->point_i,
 966                                                    item_desc,
 967                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
 968                 break;
 969
 970             default:
 971                 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"),
 972                                                    _(gr_knot_descr[draggable->point_type]),
 973                                                    item_desc,
 974                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
 975                 break;
 976         }
 977         g_free(item_desc);
 978     } else if (g_slist_length (draggables) == 2 && isA (POINT_RG_CENTER) && isA (POINT_RG_FOCUS)) {
 979         this->knot->tip = g_strdup_printf (_("Radial gradient <b>center</b> and <b>focus</b>; drag with <b>Shift</b> to separate focus"));
 980     } else {
 981         int length = g_slist_length (this->draggables);
 982         this->knot->tip = g_strdup_printf (ngettext("Gradient point shared by <b>%d</b> gradient; drag with <b>Shift</b> to separate",
 983                                                     "Gradient point shared by <b>%d</b> gradients; drag with <b>Shift</b> to separate",
 984                                                     length),
 985                                            length);
 986     }
 987 }
 988
 989 /**
 990 Adds a draggable to the dragger
 991  */
 992 void
 993 GrDragger::updateKnotShape ()
 994 {
 995     if (!draggables)
 996         return;
 997     GrDraggable *last = (GrDraggable *) g_slist_last(draggables)->data;
 998     g_object_set (G_OBJECT (this->knot->item), "shape", gr_knot_shapes[last->point_type], NULL);
 999 }
1000
1001 /**
1002 Adds a draggable to the dragger
1003  */
1004 void
1005 GrDragger::addDraggable (GrDraggable *draggable)
1006 {
1007     this->draggables = g_slist_prepend (this->draggables, draggable);
1008
1009     this->updateTip();
1010 }
1011
1012
1013 /**
1014 Moves this dragger to the point of the given draggable, acting upon all other draggables
1015  */
1016 void
1017 GrDragger::moveThisToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1018 {
1019     this->point = sp_item_gradient_get_coords (item, point_type, point_i, fill_or_stroke);
1020     this->point_original = this->point;
1021
1022     sp_knot_moveto (this->knot, &(this->point));
1023
1024     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1025         GrDraggable *da = (GrDraggable *) i->data;
1026         if ( (da->item == item) &&
1027              (point_type == -1 || da->point_type == point_type) &&
1028              (point_i == -1 || da->point_i == point_i) &&
1029              (da->fill_or_stroke == fill_or_stroke) ) {
1030             continue;
1031         }
1032         sp_item_gradient_set_coords (da->item, da->point_type, da->point_i, this->point, da->fill_or_stroke, write_repr, false);
1033     }
1034     // FIXME: here we should also call this->updateDependencies(write_repr); to propagate updating, but how to prevent loops?
1035 }
1036
1037
1038 /**
1039 Moves all midstop draggables that depend on this one
1040  */
1041 void
1042 GrDragger::updateMidstopDependencies (GrDraggable *draggable, bool write_repr) {
1043     SPObject *server = draggable->getServer();
1044     if (!server)
1045         return;
1046     guint num = SP_GRADIENT(server)->vector.stops.size();
1047     if (num <= 2) return;
1048
1049     if ( SP_IS_LINEARGRADIENT(server) ) {
1050         for ( guint i = 1; i < num - 1; i++ ) {
1051             this->moveOtherToDraggable (draggable->item, POINT_LG_MID, i, draggable->fill_or_stroke, write_repr);
1052         }
1053     } else  if ( SP_IS_RADIALGRADIENT(server) ) {
1054         for ( guint i = 1; i < num - 1; i++ ) {
1055             this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, i, draggable->fill_or_stroke, write_repr);
1056             this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, i, draggable->fill_or_stroke, write_repr);
1057         }
1058     }
1059 }
1060
1061
1062 /**
1063 Moves all draggables that depend on this one
1064  */
1065 void
1066 GrDragger::updateDependencies (bool write_repr)
1067 {
1068     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1069         GrDraggable *draggable = (GrDraggable *) i->data;
1070         switch (draggable->point_type) {
1071             case POINT_LG_BEGIN:
1072                 {
1073                     // the end point is dependent only when dragging with ctrl+shift
1074                     this->moveOtherToDraggable (draggable->item, POINT_LG_END, -1, draggable->fill_or_stroke, write_repr);
1075
1076                     this->updateMidstopDependencies (draggable, write_repr);
1077                 }
1078                 break;
1079             case POINT_LG_END:
1080                 {
1081                     // the begin point is dependent only when dragging with ctrl+shift
1082                     this->moveOtherToDraggable (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke, write_repr);
1083
1084                     this->updateMidstopDependencies (draggable, write_repr);
1085                 }
1086                 break;
1087             case POINT_LG_MID:
1088                 // no other nodes depend on mid points.
1089                 break;
1090             case POINT_RG_R2:
1091                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1092                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1093                 this->updateMidstopDependencies (draggable, write_repr);
1094                 break;
1095             case POINT_RG_R1:
1096                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1097                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1098                 this->updateMidstopDependencies (draggable, write_repr);
1099                 break;
1100             case POINT_RG_CENTER:
1101                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1102                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1103                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1104                 this->updateMidstopDependencies (draggable, write_repr);
1105                 break;
1106             case POINT_RG_FOCUS:
1107                 // nothing can depend on that
1108                 break;
1109             case POINT_RG_MID1:
1110                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, draggable->point_i, draggable->fill_or_stroke, write_repr);
1111                 break;
1112             case POINT_RG_MID2:
1113                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, draggable->point_i, draggable->fill_or_stroke, write_repr);
1114                 break;
1115             default:
1116                 break;
1117         }
1118     }
1119 }
1120
1121
1122
1123 GrDragger::GrDragger (GrDrag *parent, NR::Point p, GrDraggable *draggable)
1124 {
1125     this->draggables = NULL;
1126
1127     this->parent = parent;
1128
1129     this->point = p;
1130     this->point_original = p;
1131
1132     // create the knot
1133     this->knot = sp_knot_new (parent->desktop, NULL);
1134     this->knot->setMode(SP_KNOT_MODE_XOR);
1135     this->knot->setFill(GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_NORMAL);
1136     this->knot->setStroke(0x000000ff, 0x000000ff, 0x000000ff);
1137     sp_knot_update_ctrl(this->knot);
1138
1139     // move knot to the given point
1140     sp_knot_set_position (this->knot, &p, SP_KNOT_STATE_NORMAL);
1141     sp_knot_show (this->knot);
1142
1143     // connect knot's signals
1144     if ( (draggable)  // it can be NULL if a node in unsnapped (eg. focus point unsnapped from center)
1145                        // luckily, midstops never snap to other nodes so are never unsnapped...
1146          && ( (draggable->point_type == POINT_LG_MID)
1147               || (draggable->point_type == POINT_RG_MID1)
1148               || (draggable->point_type == POINT_RG_MID2) ) )
1149     {
1150         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_midpoint_handler), this);
1151     } else {
1152         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_handler), this);
1153     }
1154     g_signal_connect (G_OBJECT (this->knot), "clicked", G_CALLBACK (gr_knot_clicked_handler), this);
1155     g_signal_connect (G_OBJECT (this->knot), "doubleclicked", G_CALLBACK (gr_knot_doubleclicked_handler), this);
1156     g_signal_connect (G_OBJECT (this->knot), "grabbed", G_CALLBACK (gr_knot_grabbed_handler), this);
1157     g_signal_connect (G_OBJECT (this->knot), "ungrabbed", G_CALLBACK (gr_knot_ungrabbed_handler), this);
1158
1159     // add the initial draggable
1160     if (draggable)
1161         this->addDraggable (draggable);
1162     updateKnotShape();
1163 }
1164
1165 GrDragger::~GrDragger ()
1166 {
1167     // unselect if it was selected
1168     this->parent->setDeselected(this);
1169
1170     // disconnect signals
1171     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_moved_handler), this);
1172     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_clicked_handler), this);
1173     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_doubleclicked_handler), this);
1174     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_grabbed_handler), this);
1175     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_ungrabbed_handler), this);
1176
1177     /* unref should call destroy */
1178     g_object_unref (G_OBJECT (this->knot));
1179
1180     // delete all draggables
1181     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1182         delete ((GrDraggable *) i->data);
1183     }
1184     g_slist_free (this->draggables);
1185     this->draggables = NULL;
1186 }
1187
1188 /**
1189 Select the dragger which has the given draggable.
1190 */
1191 GrDragger *
1192 GrDrag::getDraggerFor (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1193 {
1194     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1195         GrDragger *dragger = (GrDragger *) i->data;
1196         for (GSList const* j = dragger->draggables; j != NULL; j = j->next) {
1197             GrDraggable *da2 = (GrDraggable *) j->data;
1198             if ( (da2->item == item) &&
1199                  (point_type == -1 || da2->point_type == point_type) && // -1 means this does not matter
1200                  (point_i == -1 || da2->point_i == point_i) && // -1 means this does not matter
1201                  (da2->fill_or_stroke == fill_or_stroke)) {
1202                 return (dragger);
1203             }
1204         }
1205     }
1206     return NULL;
1207 }
1208
1209
1210 void
1211 GrDragger::moveOtherToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1212 {
1213     GrDragger *d = this->parent->getDraggerFor (item, point_type, point_i, fill_or_stroke);
1214     if (d && d !=  this) {
1215         d->moveThisToDraggable (item, point_type, point_i, fill_or_stroke, write_repr);
1216     }
1217 }
1218
1219
1220 /**
1221   Draw this dragger as selected
1222 */
1223 void
1224 GrDragger::select()
1225 {
1226     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_SELECTED;
1227     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_SELECTED, NULL);
1228 }
1229
1230 /**
1231   Draw this dragger as normal (deselected)
1232 */
1233 void
1234 GrDragger::deselect()
1235 {
1236     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_NORMAL;
1237     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_NORMAL, NULL);
1238 }
1239
1240 bool
1241 GrDragger::isSelected()
1242 {
1243     return g_list_find (parent->selected, this);
1244 }
1245
1246 /**
1247 \brief Deselect all stops/draggers (private)
1248 */
1249 void
1250 GrDrag::deselect_all()
1251 {
1252     while (selected) {
1253         ( (GrDragger*) selected->data)->deselect();
1254         selected = g_list_remove(selected, selected->data);
1255     }
1256 }
1257
1258 /**
1259 \brief Deselect all stops/draggers (public; emits signal)
1260 */
1261 void
1262 GrDrag::deselectAll()
1263 {
1264     deselect_all();
1265     this->desktop->emitToolSubselectionChanged(NULL);
1266 }
1267
1268 /**
1269 \brief Select all stops/draggers
1270 */
1271 void
1272 GrDrag::selectAll()
1273 {
1274     for (GList *l = this->draggers; l != NULL; l = l->next) {
1275         GrDragger *d = ((GrDragger *) l->data);
1276         setSelected (d, true, true);
1277     }
1278 }
1279
1280 /**
1281 \brief Select all stops/draggers that match the coords
1282 */
1283 void
1284 GrDrag::selectByCoords(std::vector<NR::Point> coords)
1285 {
1286     for (GList *l = this->draggers; l != NULL; l = l->next) {
1287         GrDragger *d = ((GrDragger *) l->data);
1288         for (guint k = 0; k < coords.size(); k++) {
1289             if (NR::L2 (d->point - coords[k]) < 1e-4) {
1290                 setSelected (d, true, true);
1291             }
1292         }
1293     }
1294 }
1295
1296
1297 /**
1298 \brief Select all stops/draggers that fall within the rect
1299 */
1300 void
1301 GrDrag::selectRect(NR::Rect const &r)
1302 {
1303     for (GList *l = this->draggers; l != NULL; l = l->next) {
1304         GrDragger *d = ((GrDragger *) l->data);
1305         if (r.contains(d->point)) {
1306            setSelected (d, true, true);
1307         }
1308     }
1309 }
1310
1311 /**
1312 \brief Select a dragger
1313 \param dragger       The dragger to select
1314 \param add_to_selection   If true, add to selection, otherwise deselect others
1315 \param override      If true, always select this node, otherwise toggle selected status
1316 */
1317 void
1318 GrDrag::setSelected (GrDragger *dragger, bool add_to_selection, bool override)
1319 {
1320     GrDragger *seldragger = NULL;
1321
1322     if (add_to_selection) {
1323         if (!dragger) return;
1324         if (override) {
1325             if (!g_list_find(selected, dragger)) {
1326                 selected = g_list_prepend(selected, dragger);
1327             }
1328             dragger->select();
1329             seldragger = dragger;
1330         } else { // toggle
1331             if (g_list_find(selected, dragger)) {
1332                 selected = g_list_remove(selected, dragger);
1333                 dragger->deselect();
1334                 if (selected) {
1335                     seldragger = (GrDragger*) selected->data; // select the dragger that is first in the list
1336                 }
1337             } else {
1338                 selected = g_list_prepend(selected, dragger);
1339                 dragger->select();
1340                 seldragger = dragger;
1341             }
1342         }
1343     } else {
1344         deselect_all();
1345         if (dragger) {
1346             selected = g_list_prepend(selected, dragger);
1347             dragger->select();
1348             seldragger = dragger;
1349         }
1350     }
1351     if (seldragger) {
1352         this->desktop->emitToolSubselectionChanged((gpointer) seldragger);
1353     }
1354 }
1355
1356 /**
1357 \brief Deselect a dragger
1358 \param dragger       The dragger to deselect
1359 */
1360 void
1361 GrDrag::setDeselected (GrDragger *dragger)
1362 {
1363     if (g_list_find(selected, dragger)) {
1364         selected = g_list_remove(selected, dragger);
1365         dragger->deselect();
1366     }
1367     this->desktop->emitToolSubselectionChanged((gpointer) (selected ? selected->data : NULL ));
1368 }
1369
1370
1371
1372 /**
1373 Create a line from p1 to p2 and add it to the lines list
1374  */
1375 void
1376 GrDrag::addLine (NR::Point p1, NR::Point p2, guint32 rgba)
1377 {
1378     SPCanvasItem *line = sp_canvas_item_new(sp_desktop_controls(this->desktop),
1379                                                             SP_TYPE_CTRLLINE, NULL);
1380     sp_ctrlline_set_coords(SP_CTRLLINE(line), p1, p2);
1381     if (rgba != GR_LINE_COLOR_FILL) // fill is the default, so don't set color for it to speed up redraw
1382         sp_ctrlline_set_rgba32 (SP_CTRLLINE(line), rgba);
1383     sp_canvas_item_show (line);
1384     this->lines = g_slist_append (this->lines, line);
1385 }
1386
1387 /**
1388 If there already exists a dragger within MERGE_DIST of p, add the draggable to it; otherwise create
1389 new dragger and add it to draggers list
1390  */
1391 void
1392 GrDrag::addDragger (GrDraggable *draggable)
1393 {
1394     NR::Point p = sp_item_gradient_get_coords (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
1395
1396     for (GList *i = this->draggers; i != NULL; i = i->next) {
1397         GrDragger *dragger = (GrDragger *) i->data;
1398         if (dragger->mayMerge (draggable) && NR::L2 (dragger->point - p) < MERGE_DIST) {
1399             // distance is small, merge this draggable into dragger, no need to create new dragger
1400             dragger->addDraggable (draggable);
1401             dragger->updateKnotShape();
1402             return;
1403         }
1404     }
1405
1406     GrDragger *new_dragger = new GrDragger(this, p, draggable);
1407     // fixme: draggers should be added AFTER the last one: this way tabbing through them will be from begin to end.
1408     this->draggers = g_list_append (this->draggers, new_dragger);
1409 }
1410
1411 /**
1412 Add draggers for the radial gradient rg on item
1413 */
1414 void
1415 GrDrag::addDraggersRadial (SPRadialGradient *rg, SPItem *item, bool fill_or_stroke)
1416 {
1417     addDragger (new GrDraggable (item, POINT_RG_CENTER, 0, fill_or_stroke));
1418     guint num = rg->vector.stops.size();
1419     if (num > 2) {
1420         for ( guint i = 1; i < num - 1; i++ ) {
1421             addDragger (new GrDraggable (item, POINT_RG_MID1, i, fill_or_stroke));
1422         }
1423     }
1424     addDragger (new GrDraggable (item, POINT_RG_R1, num-1, fill_or_stroke));
1425     if (num > 2) {
1426         for ( guint i = 1; i < num - 1; i++ ) {
1427             addDragger (new GrDraggable (item, POINT_RG_MID2, i, fill_or_stroke));
1428         }
1429     }
1430     addDragger (new GrDraggable (item, POINT_RG_R2, num-1, fill_or_stroke));
1431     addDragger (new GrDraggable (item, POINT_RG_FOCUS, 0, fill_or_stroke));
1432 }
1433
1434 /**
1435 Add draggers for the linear gradient lg on item
1436 */
1437 void
1438 GrDrag::addDraggersLinear (SPLinearGradient *lg, SPItem *item, bool fill_or_stroke)
1439 {
1440     addDragger (new GrDraggable (item, POINT_LG_BEGIN, 0, fill_or_stroke));
1441     guint num = lg->vector.stops.size();
1442     if (num > 2) {
1443         for ( guint i = 1; i < num - 1; i++ ) {
1444             addDragger (new GrDraggable (item, POINT_LG_MID, i, fill_or_stroke));
1445         }
1446     }
1447     addDragger (new GrDraggable (item, POINT_LG_END, num-1, fill_or_stroke));
1448 }
1449
1450 /**
1451 Artificially grab the knot of the dragger with this draggable; used by the gradient context
1452 */
1453 void
1454 GrDrag::grabKnot (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, gint x, gint y, guint32 etime)
1455 {
1456     GrDragger *dragger = getDraggerFor (item, point_type, point_i, fill_or_stroke);
1457     if (dragger) {
1458         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1459     }
1460 }
1461
1462 /**
1463 Regenerates the draggers list from the current selection; is called when selection is changed or
1464 modified, also when a radial dragger needs to update positions of other draggers in the gradient
1465 */
1466 void
1467 GrDrag::updateDraggers ()
1468 {
1469     while (selected) {
1470         selected = g_list_remove(selected, selected->data);
1471     }
1472     // delete old draggers
1473     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1474         delete ((GrDragger *) i->data);
1475     }
1476     g_list_free (this->draggers);
1477     this->draggers = NULL;
1478
1479     g_return_if_fail (this->selection != NULL);
1480
1481     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1482
1483         SPItem *item = SP_ITEM(i->data);
1484         SPStyle *style = SP_OBJECT_STYLE (item);
1485
1486         if (style && (style->fill.isPaintserver())) {
1487             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1488             if (SP_IS_LINEARGRADIENT (server)) {
1489                 addDraggersLinear (SP_LINEARGRADIENT (server), item, true);
1490             } else if (SP_IS_RADIALGRADIENT (server)) {
1491                 addDraggersRadial (SP_RADIALGRADIENT (server), item, true);
1492             }
1493         }
1494
1495         if (style && (style->stroke.isPaintserver())) {
1496             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1497             if (SP_IS_LINEARGRADIENT (server)) {
1498                 addDraggersLinear (SP_LINEARGRADIENT (server), item, false);
1499             } else if (SP_IS_RADIALGRADIENT (server)) {
1500                 addDraggersRadial (SP_RADIALGRADIENT (server), item, false);
1501             }
1502         }
1503     }
1504 }
1505
1506 /**
1507 Regenerates the lines list from the current selection; is called on each move of a dragger, so that
1508 lines are always in sync with the actual gradient
1509 */
1510 void
1511 GrDrag::updateLines ()
1512 {
1513     // delete old lines
1514     for (GSList const *i = this->lines; i != NULL; i = i->next) {
1515         gtk_object_destroy( GTK_OBJECT (i->data));
1516     }
1517     g_slist_free (this->lines);
1518     this->lines = NULL;
1519
1520     g_return_if_fail (this->selection != NULL);
1521
1522     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1523
1524         SPItem *item = SP_ITEM(i->data);
1525
1526         SPStyle *style = SP_OBJECT_STYLE (item);
1527
1528         if (style && (style->fill.isPaintserver())) {
1529             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1530             if (SP_IS_LINEARGRADIENT (server)) {
1531                 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);
1532             } else if (SP_IS_RADIALGRADIENT (server)) {
1533                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, true);
1534                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, true), GR_LINE_COLOR_FILL);
1535                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, true), GR_LINE_COLOR_FILL);
1536             }
1537         }
1538
1539         if (style && (style->stroke.isPaintserver())) {
1540             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1541             if (SP_IS_LINEARGRADIENT (server)) {
1542                 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);
1543             } else if (SP_IS_RADIALGRADIENT (server)) {
1544                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, false);
1545                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, false), GR_LINE_COLOR_STROKE);
1546                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, false), GR_LINE_COLOR_STROKE);
1547             }
1548         }
1549     }
1550 }
1551
1552 /**
1553 Regenerates the levels list from the current selection
1554 */
1555 void
1556 GrDrag::updateLevels ()
1557 {
1558     hor_levels.clear();
1559     vert_levels.clear();
1560
1561     g_return_if_fail (this->selection != NULL);
1562
1563     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1564         SPItem *item = SP_ITEM(i->data);
1565         NR::Maybe<NR::Rect> rect = sp_item_bbox_desktop (item);
1566         if (rect) {
1567             // Remember the edges of the bbox and the center axis
1568             hor_levels.push_back(rect->min()[NR::Y]);
1569             hor_levels.push_back(rect->max()[NR::Y]);
1570             hor_levels.push_back(0.5 * (rect->min()[NR::Y] + rect->max()[NR::Y]));
1571             vert_levels.push_back(rect->min()[NR::X]);
1572             vert_levels.push_back(rect->max()[NR::X]);
1573             vert_levels.push_back(0.5 * (rect->min()[NR::X] + rect->max()[NR::X]));
1574         }
1575     }
1576 }
1577
1578 void
1579 GrDrag::selected_reverse_vector ()
1580 {
1581     if (selected == NULL)
1582         return;
1583
1584     for (GSList const* i = ( (GrDragger*) selected->data )->draggables; i != NULL; i = i->next) {
1585         GrDraggable *draggable = (GrDraggable *) i->data;
1586
1587         sp_item_gradient_reverse_vector (draggable->item, draggable->fill_or_stroke);
1588     }
1589 }
1590
1591 void
1592 GrDrag::selected_move_nowrite (double x, double y, bool scale_radial)
1593 {
1594     selected_move (x, y, false, scale_radial);
1595 }
1596
1597 void
1598 GrDrag::selected_move (double x, double y, bool write_repr, bool scale_radial)
1599 {
1600     if (selected == NULL)
1601         return;
1602
1603     bool did = false;
1604
1605     for (GList *i = selected; i != NULL; i = i->next) {
1606         GrDragger *d = (GrDragger *) i->data;
1607
1608         if (!d->isA(POINT_LG_MID) && !d->isA(POINT_RG_MID1) && !d->isA(POINT_RG_MID2)) {
1609             // if this is a an endpoint,
1610
1611             // Moving an rg center moves its focus and radii as well.
1612             // therefore, if this is a focus or radius and if selection
1613             // contains the center as well, do not move this one
1614             if (d->isA(POINT_RG_R1) || d->isA(POINT_RG_R2) ||
1615                 (d->isA(POINT_RG_FOCUS) && !d->isA(POINT_RG_CENTER))) {
1616                 bool skip_radius_with_center = false;
1617                 for (GList *di = selected; di != NULL; di = di->next) {
1618                     GrDragger *d_new = (GrDragger *) di->data;
1619                     if (d_new->isA (((GrDraggable *) d->draggables->data)->item,
1620                                     POINT_RG_CENTER,
1621                                     0,
1622                                     ((GrDraggable *) d->draggables->data)->fill_or_stroke)) {
1623                         // FIXME: here we take into account only the first draggable!
1624                         skip_radius_with_center = true;
1625                     }
1626                 }
1627                 if (skip_radius_with_center)
1628                     continue;
1629             }
1630
1631             did = true;
1632             d->point += NR::Point (x, y);
1633             d->point_original = d->point;
1634             sp_knot_moveto (d->knot, &(d->point));
1635
1636             d->fireDraggables (write_repr, scale_radial);
1637
1638             d->updateDependencies(write_repr);
1639         }
1640
1641         if (write_repr && did) {
1642             // we did an undoable action
1643             sp_document_maybe_done (sp_desktop_document (desktop), "grmoveh", SP_VERB_CONTEXT_GRADIENT,
1644                                     _("Move gradient handle(s)"));
1645             return;
1646         }
1647
1648     }
1649
1650     if (!did) { // none of the end draggers are selected, so let's try to move the mids
1651
1652         GrDragger *dragger = (GrDragger *) selected->data;
1653         // a midpoint dragger can (logically) only contain one GrDraggable
1654         GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
1655
1656         NR::Point begin(0,0), end(0,0);
1657         NR::Point low_lim(0,0), high_lim(0,0);
1658
1659         SPObject *server = draggable->getServer();
1660         GSList *moving = NULL;
1661         gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
1662
1663         NR::Point p(x, y);
1664         p = snap_vector_midpoint (dragger->point + p, low_lim, high_lim, 0);
1665         NR::Point displacement = p - dragger->point;
1666
1667         for (GSList const* i = moving; i != NULL; i = i->next) {
1668             GrDragger *drg = (GrDragger*) i->data;
1669             SPKnot *drgknot = drg->knot;
1670             drg->point += displacement;
1671             sp_knot_moveto (drgknot, & drg->point);
1672             drg->fireDraggables (true);
1673             drg->updateDependencies(true);
1674             did = true;
1675         }
1676
1677         g_slist_free(moving);
1678
1679         if (write_repr && did) {
1680             // we did an undoable action
1681             sp_document_maybe_done (sp_desktop_document (desktop), "grmovem", SP_VERB_CONTEXT_GRADIENT,
1682                                     _("Move gradient mid stop(s)"));
1683         }
1684     }
1685 }
1686
1687 void
1688 GrDrag::selected_move_screen (double x, double y)
1689 {
1690     gdouble zoom = desktop->current_zoom();
1691     gdouble zx = x / zoom;
1692     gdouble zy = y / zoom;
1693
1694     selected_move (zx, zy);
1695 }
1696
1697 /**
1698 Select the knot next to the last selected one and deselect all other selected.
1699 */
1700 GrDragger *
1701 GrDrag::select_next ()
1702 {
1703     GrDragger *d = NULL;
1704     if (selected == NULL || g_list_find(draggers, selected->data)->next == NULL) {
1705         if (draggers)
1706             d = (GrDragger *) draggers->data;
1707     } else {
1708         d = (GrDragger *) g_list_find(draggers, selected->data)->next->data;
1709     }
1710     if (d)
1711         setSelected (d);
1712     return d;
1713 }
1714
1715 /**
1716 Select the knot previous from the last selected one and deselect all other selected.
1717 */
1718 GrDragger *
1719 GrDrag::select_prev ()
1720 {
1721     GrDragger *d = NULL;
1722     if (selected == NULL || g_list_find(draggers, selected->data)->prev == NULL) {
1723         if (draggers)
1724             d = (GrDragger *) g_list_last (draggers)->data;
1725     } else {
1726         d = (GrDragger *) g_list_find(draggers, selected->data)->prev->data;
1727     }
1728     if (d)
1729         setSelected (d);
1730     return d;
1731 }
1732
1733
1734 // FIXME: i.m.o. an ugly function that I just made to work, but... aargh! (Johan)
1735 void
1736 GrDrag::deleteSelected (bool just_one)
1737 {
1738     if (!selected) return;
1739
1740     SPDocument *document = false;
1741
1742     struct StructStopInfo {
1743         SPStop * spstop;
1744         GrDraggable * draggable;
1745         SPGradient * gradient;
1746         SPGradient * vector;
1747     };
1748
1749     GSList *midstoplist = NULL;  // list of stops that must be deleted (will be deleted first)
1750     GSList *endstoplist = NULL;  // list of stops that must be deleted
1751     while (selected) {
1752         GrDragger *dragger = (GrDragger*) selected->data;
1753         for (GSList * drgble = dragger->draggables; drgble != NULL; drgble = drgble->next) {
1754             GrDraggable *draggable = (GrDraggable*) drgble->data;
1755             SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
1756             SPGradient *vector   = sp_gradient_get_forked_vector_if_necessary (gradient, false);
1757
1758             switch (draggable->point_type) {
1759                 case POINT_LG_MID:
1760                 case POINT_RG_MID1:
1761                 case POINT_RG_MID2:
1762                     {
1763                         SPStop *stop = sp_get_stop_i(vector, draggable->point_i);
1764                         // check if already present in list. (e.g. when both RG_MID1 and RG_MID2 were selected)
1765                         bool present = false;
1766                         for (GSList const * l = midstoplist; l != NULL; l = l->next) {
1767                             if ( (SPStop*)l->data == stop ) {
1768                                 present = true;
1769                                 break; // no need to search further.
1770                             }
1771                         }
1772                         if (!present)
1773                             midstoplist = g_slist_append(midstoplist, stop);
1774                     }
1775                     break;
1776                 case POINT_LG_BEGIN:
1777                 case POINT_LG_END:
1778                 case POINT_RG_CENTER:
1779                 case POINT_RG_R1:
1780                 case POINT_RG_R2:
1781                     {
1782                         SPStop *stop = NULL;
1783                         if ( (draggable->point_type == POINT_LG_BEGIN) || (draggable->point_type == POINT_RG_CENTER) ) {
1784                             stop = sp_first_stop(vector);
1785                         } else {
1786                             stop = sp_last_stop(vector);
1787                         }
1788                         if (stop) {
1789                             StructStopInfo *stopinfo = new StructStopInfo;
1790                             stopinfo->spstop = stop;
1791                             stopinfo->draggable = draggable;
1792                             stopinfo->gradient = gradient;
1793                             stopinfo->vector = vector;
1794                             // check if already present in list. (e.g. when both R1 and R2 were selected)
1795                             bool present = false;
1796                             for (GSList const * l = endstoplist; l != NULL; l = l->next) {
1797                                 if ( ((StructStopInfo*)l->data)->spstop == stopinfo->spstop ) {
1798                                     present = true;
1799                                     break; // no need to search further.
1800                                 }
1801                             }
1802                             if (!present)
1803                                 endstoplist = g_slist_append(endstoplist, stopinfo);
1804                         }
1805                     }
1806                     break;
1807                 default:
1808                     break;
1809             }
1810         }
1811         selected = g_list_remove(selected, dragger);
1812         if ( just_one ) break; // iterate once if just_one is set.
1813     }
1814     while (midstoplist) {
1815         SPStop *stop = (SPStop*) midstoplist->data;
1816         document = SP_OBJECT_DOCUMENT (stop);
1817         Inkscape::XML::Node * parent = SP_OBJECT_REPR(stop)->parent();
1818         parent->removeChild(SP_OBJECT_REPR(stop));
1819         midstoplist = g_slist_remove(midstoplist, stop);
1820     }
1821     while (endstoplist) {
1822         StructStopInfo *stopinfo  = (StructStopInfo*) endstoplist->data;
1823         document = SP_OBJECT_DOCUMENT (stopinfo->spstop);
1824
1825         // 2 is the minimum, cannot delete more than that without deleting the whole vector
1826         // cannot use vector->vector.stops.size() because the vector might be invalidated by deletion of a midstop
1827         // manually count the children, don't know if there already exists a function for this...
1828         int len = 0;
1829         for ( SPObject *child = sp_object_first_child(stopinfo->vector) ;
1830               child != NULL ;
1831               child = SP_OBJECT_NEXT(child) )
1832         {
1833             if ( SP_IS_STOP(child) )  len ++;
1834         }
1835         if (len > 2)
1836         {
1837             switch (stopinfo->draggable->point_type) {
1838                 case POINT_LG_BEGIN:
1839                     {
1840                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1841
1842                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
1843                         NR::Point oldbegin = NR::Point (lg->x1.computed, lg->y1.computed);
1844                         NR::Point end = NR::Point (lg->x2.computed, lg->y2.computed);
1845                         SPStop *stop = sp_first_stop(stopinfo->vector);
1846                         gdouble offset = stop->offset;
1847                         NR::Point newbegin = oldbegin + offset * (end - oldbegin);
1848                         lg->x1.computed = newbegin[NR::X];
1849                         lg->y1.computed = newbegin[NR::Y];
1850
1851                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
1852                         sp_repr_set_svg_double(repr, "x1", lg->x1.computed);
1853                         sp_repr_set_svg_double(repr, "y1", lg->y1.computed);
1854                         stop->offset = 0;
1855                         sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", 0);
1856
1857                         // iterate through midstops to set new offset values such that they won't move on canvas.
1858                         SPStop *laststop = sp_last_stop(stopinfo->vector);
1859                         stop = sp_next_stop(stop);
1860                         while ( stop != laststop ) {
1861                             stop->offset = (stop->offset - offset)/(1 - offset);
1862                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
1863                             stop = sp_next_stop(stop);
1864                         }
1865                     }
1866                     break;
1867                 case POINT_LG_END:
1868                     {
1869                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1870
1871                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
1872                         NR::Point begin = NR::Point (lg->x1.computed, lg->y1.computed);
1873                         NR::Point oldend = NR::Point (lg->x2.computed, lg->y2.computed);
1874                         SPStop *laststop = sp_last_stop(stopinfo->vector);
1875                         gdouble offset = laststop->offset;
1876                         NR::Point newend = begin + offset * (oldend - begin);
1877                         lg->x2.computed = newend[NR::X];
1878                         lg->y2.computed = newend[NR::Y];
1879
1880                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
1881                         sp_repr_set_svg_double(repr, "x2", lg->x2.computed);
1882                         sp_repr_set_svg_double(repr, "y2", lg->y2.computed);
1883                         laststop->offset = 1;
1884                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
1885
1886                         // iterate through midstops to set new offset values such that they won't move on canvas.
1887                         SPStop *stop = sp_first_stop(stopinfo->vector);
1888                         stop = sp_next_stop(stop);
1889                         while ( stop != laststop ) {
1890                             stop->offset = stop->offset / offset;
1891                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
1892                             stop = sp_next_stop(stop);
1893                         }
1894                     }
1895                     break;
1896                 case POINT_RG_CENTER:
1897                     {
1898                         SPStop *newfirst = sp_next_stop (stopinfo->spstop);
1899                         if (newfirst) {
1900                             newfirst->offset = 0;
1901                             sp_repr_set_css_double (SP_OBJECT_REPR (newfirst), "offset", 0);
1902                         }
1903                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1904                     }
1905                     break;
1906                 case POINT_RG_R1:
1907                 case POINT_RG_R2:
1908                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1909
1910                         SPRadialGradient *rg = SP_RADIALGRADIENT(stopinfo->gradient);
1911                         double oldradius = rg->r.computed;
1912                         SPStop *laststop = sp_last_stop(stopinfo->vector);
1913                         gdouble offset = laststop->offset;
1914                         double newradius = offset * oldradius;
1915                         rg->r.computed = newradius;
1916
1917                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(rg);
1918                         sp_repr_set_svg_double(repr, "r", rg->r.computed);
1919                         laststop->offset = 1;
1920                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
1921
1922                         // iterate through midstops to set new offset values such that they won't move on canvas.
1923                         SPStop *stop = sp_first_stop(stopinfo->vector);
1924                         stop = sp_next_stop(stop);
1925                         while ( stop != laststop ) {
1926                             stop->offset = stop->offset / offset;
1927                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
1928                             stop = sp_next_stop(stop);
1929                         }
1930                         break;
1931             }
1932         }
1933         else
1934         { // delete the gradient from the object. set fill to unset  FIXME: set to fill of unselected node?
1935             SPCSSAttr *css = sp_repr_css_attr_new ();
1936
1937             // stopinfo->spstop is the selected stop
1938             Inkscape::XML::Node *unselectedrepr = SP_OBJECT_REPR(stopinfo->vector)->firstChild();
1939             if (unselectedrepr == SP_OBJECT_REPR(stopinfo->spstop) ) {
1940                 unselectedrepr = unselectedrepr->next();
1941             }
1942
1943             if (unselectedrepr == NULL) {
1944                 if (stopinfo->draggable->fill_or_stroke) {
1945                     sp_repr_css_unset_property (css, "fill");
1946                 } else {
1947                     sp_repr_css_unset_property (css, "stroke");
1948                 }
1949             } else {
1950                 SPCSSAttr *stopcss = sp_repr_css_attr(unselectedrepr, "style");
1951                 if (stopinfo->draggable->fill_or_stroke) {
1952                     sp_repr_css_set_property(css, "fill", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
1953                     sp_repr_css_set_property(css, "fill-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
1954                 } else {
1955                     sp_repr_css_set_property(css, "stroke", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
1956                     sp_repr_css_set_property(css, "stroke-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
1957                 }
1958                 sp_repr_css_attr_unref (stopcss);
1959             }
1960
1961             sp_repr_css_change (SP_OBJECT_REPR (stopinfo->draggable->item), css, "style");
1962             sp_repr_css_attr_unref (css);
1963         }
1964
1965         endstoplist = g_slist_remove(endstoplist, stopinfo);
1966         delete stopinfo;
1967     }
1968
1969     if (document) {
1970         sp_document_done ( document, SP_VERB_CONTEXT_GRADIENT, _("Delete gradient stop(s)") );
1971     }
1972 }
1973
1974
1975 /*
1976   Local Variables:
1977   mode:c++
1978   c-file-style:"stroustrup"
1979   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1980   indent-tabs-mode:nil
1981   fill-column:99
1982   End:
1983 */
1984 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :