src/gradient-drag.cpp

   1 #define __GRADIENT_DRAG_C__
   2
   3 /*
   4  * On-canvas gradient dragging
   5  *
   6  * Authors:
   7  *   bulia byak <buliabyak@users.sf.net>
   8  *   Johan Engelen <j.b.c.engelen@ewi.utwente.nl>
   9  *
  10  * Copyright (C) 2007 Johan Engelen
  11  * Copyright (C) 2005 Authors
  12  *
  13  * Released under GNU GPL, read the file 'COPYING' for more information
  14  */
  15
  16 #ifdef HAVE_CONFIG_H
  17 #include "config.h"
  18 #endif
  19
  20 #include <glibmm/i18n.h>
  21
  22 #include "desktop-handles.h"
  23 #include "selection.h"
  24 #include "desktop.h"
  25 #include "desktop-style.h"
  26 #include "document.h"
  27 #include "display/sp-ctrlline.h"
  28
  29 #include "xml/repr.h"
  30 #include "svg/css-ostringstream.h"
  31
  32 #include "svg/svg.h"
  33
  34 #include "prefs-utils.h"
  35 #include "sp-item.h"
  36 #include "style.h"
  37 #include "knot.h"
  38 #include "sp-linear-gradient.h"
  39 #include "sp-radial-gradient.h"
  40 #include "gradient-chemistry.h"
  41 #include "gradient-drag.h"
  42 #include "sp-stop.h"
  43
  44 #include "snap.h"
  45 #include "sp-namedview.h"
  46
  47
  48 #define GR_KNOT_COLOR_NORMAL 0xffffff00
  49 #define GR_KNOT_COLOR_SELECTED 0x0000ff00
  50
  51 #define GR_LINE_COLOR_FILL 0x0000ff7f
  52 #define GR_LINE_COLOR_STROKE 0x9999007f
  53
  54 // screen pixels between knots when they snap:
  55 #define SNAP_DIST 5
  56
  57 // absolute distance between gradient points for them to become a single dragger when the drag is created:
  58 #define MERGE_DIST 0.1
  59
  60 // knot shapes corresponding to GrPointType enum
  61 SPKnotShapeType gr_knot_shapes [] = {
  62         SP_KNOT_SHAPE_SQUARE, //POINT_LG_BEGIN
  63         SP_KNOT_SHAPE_CIRCLE,  //POINT_LG_END
  64         SP_KNOT_SHAPE_DIAMOND, //POINT_LG_MID
  65         SP_KNOT_SHAPE_SQUARE,  // POINT_RG_CENTER
  66         SP_KNOT_SHAPE_CIRCLE,  // POINT_RG_R1
  67         SP_KNOT_SHAPE_CIRCLE,  // POINT_RG_R2
  68         SP_KNOT_SHAPE_CROSS, // POINT_RG_FOCUS
  69         SP_KNOT_SHAPE_DIAMOND, //POINT_RG_MID1
  70         SP_KNOT_SHAPE_DIAMOND //POINT_RG_MID2
  71 };
  72
  73 const gchar *gr_knot_descr [] = {
  74     N_("Linear gradient <b>start</b>"), //POINT_LG_BEGIN
  75     N_("Linear gradient <b>end</b>"),
  76     N_("Linear gradient <b>midstop</b>"),
  77     N_("Radial gradient <b>center</b>"),
  78     N_("Radial gradient <b>radius</b>"),
  79     N_("Radial gradient <b>radius</b>"),
  80     N_("Radial gradient <b>focus</b>"), // POINT_RG_FOCUS
  81     N_("Linear gradient <b>midstop</b>"),
  82     N_("Linear gradient <b>midstop</b>")
  83 };
  84
  85 static void
  86 gr_drag_sel_changed(Inkscape::Selection *selection, gpointer data)
  87 {
  88         GrDrag *drag = (GrDrag *) data;
  89         drag->updateDraggers ();
  90         drag->updateLines ();
  91         drag->updateLevels ();
  92 }
  93
  94 static void
  95 gr_drag_sel_modified (Inkscape::Selection *selection, guint flags, gpointer data)
  96 {
  97     GrDrag *drag = (GrDrag *) data;
  98     if (drag->local_change) {
  99         drag->local_change = false;
 100     } else {
 101         drag->updateDraggers ();
 102     }
 103     drag->updateLines ();
 104     drag->updateLevels ();
 105 }
 106
 107 /**
 108 When a _query_style_signal is received, check that \a property requests fill/stroke/opacity (otherwise
 109 skip), and fill the \a style with the averaged color of all draggables of the selected dragger, if
 110 any.
 111 */
 112 int
 113 gr_drag_style_query (SPStyle *style, int property, gpointer data)
 114 {
 115     GrDrag *drag = (GrDrag *) data;
 116
 117     if (property != QUERY_STYLE_PROPERTY_FILL && property != QUERY_STYLE_PROPERTY_STROKE && property != QUERY_STYLE_PROPERTY_MASTEROPACITY) {
 118         return QUERY_STYLE_NOTHING;
 119     }
 120
 121     if (!drag->selected) {
 122         return QUERY_STYLE_NOTHING;
 123     } else {
 124         int ret = QUERY_STYLE_NOTHING;
 125
 126         float cf[4];
 127         cf[0] = cf[1] = cf[2] = cf[3] = 0;
 128
 129         int count = 0;
 130
 131         for (GSList const* i = ((GrDragger*)drag->selected->data)->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 132             GrDraggable *draggable = (GrDraggable *) i->data;
 133
 134             if (ret == QUERY_STYLE_NOTHING) {
 135                 ret = QUERY_STYLE_SINGLE;
 136             } else if (ret == QUERY_STYLE_SINGLE) {
 137                 ret = QUERY_STYLE_MULTIPLE_AVERAGED;
 138             }
 139
 140             guint32 c = sp_item_gradient_stop_query_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 141             cf[0] += SP_RGBA32_R_F (c);
 142             cf[1] += SP_RGBA32_G_F (c);
 143             cf[2] += SP_RGBA32_B_F (c);
 144             cf[3] += SP_RGBA32_A_F (c);
 145
 146             count ++;
 147         }
 148
 149         if (count) {
 150             cf[0] /= count;
 151             cf[1] /= count;
 152             cf[2] /= count;
 153             cf[3] /= count;
 154
 155             // set both fill and stroke with our stop-color and stop-opacity
 156             style->fill.clear();
 157             style->fill.setColor( cf[0], cf[1], cf[2] );
 158             style->fill.set = TRUE;
 159             style->stroke.clear();
 160             style->stroke.setColor( cf[0], cf[1], cf[2] );
 161             style->stroke.set = TRUE;
 162
 163             style->fill_opacity.value = SP_SCALE24_FROM_FLOAT (1.0);
 164             style->fill_opacity.set = TRUE;
 165             style->stroke_opacity.value = SP_SCALE24_FROM_FLOAT (1.0);
 166             style->stroke_opacity.set = TRUE;
 167
 168             style->opacity.value = SP_SCALE24_FROM_FLOAT (cf[3]);
 169             style->opacity.set = TRUE;
 170         }
 171
 172         return ret;
 173     }
 174 }
 175
 176 bool
 177 gr_drag_style_set (const SPCSSAttr *css, gpointer data)
 178 {
 179     GrDrag *drag = (GrDrag *) data;
 180
 181     if (!drag->selected)
 182         return false;
 183
 184     SPCSSAttr *stop = sp_repr_css_attr_new ();
 185
 186     // See if the css contains interesting properties, and if so, translate them into the format
 187     // acceptable for gradient stops
 188
 189     // any of color properties, in order of increasing priority:
 190     if (css->attribute("flood-color"))
 191         sp_repr_css_set_property (stop, "stop-color", css->attribute("flood-color"));
 192
 193     if (css->attribute("lighting-color"))
 194         sp_repr_css_set_property (stop, "stop-color", css->attribute("lighting-color"));
 195
 196     if (css->attribute("color"))
 197         sp_repr_css_set_property (stop, "stop-color", css->attribute("color"));
 198
 199     if (css->attribute("stroke") && strcmp(css->attribute("stroke"), "none"))
 200         sp_repr_css_set_property (stop, "stop-color", css->attribute("stroke"));
 201
 202     if (css->attribute("fill") && strcmp(css->attribute("fill"), "none"))
 203         sp_repr_css_set_property (stop, "stop-color", css->attribute("fill"));
 204
 205     if (css->attribute("stop-color"))
 206         sp_repr_css_set_property (stop, "stop-color", css->attribute("stop-color"));
 207
 208
 209     if (css->attribute("stop-opacity")) { // direct setting of stop-opacity has priority
 210         sp_repr_css_set_property (stop, "stop-opacity", css->attribute("stop-opacity"));
 211     } else {  // multiply all opacity properties:
 212         gdouble accumulated = 1.0;
 213         accumulated *= sp_svg_read_percentage(css->attribute("flood-opacity"), 1.0);
 214         accumulated *= sp_svg_read_percentage(css->attribute("opacity"), 1.0);
 215         accumulated *= sp_svg_read_percentage(css->attribute("stroke-opacity"), 1.0);
 216         accumulated *= sp_svg_read_percentage(css->attribute("fill-opacity"), 1.0);
 217
 218         Inkscape::CSSOStringStream os;
 219         os << accumulated;
 220         sp_repr_css_set_property (stop, "stop-opacity", os.str().c_str());
 221
 222         if ((css->attribute("fill") && !strcmp(css->attribute("fill"), "none")) ||
 223             (css->attribute("stroke") && !strcmp(css->attribute("stroke"), "none")))
 224             sp_repr_css_set_property (stop, "stop-opacity", "0"); // if set to none, don't change color, set opacity to 0
 225     }
 226
 227     if (!stop->attributeList()) { // nothing for us here, pass it on
 228         sp_repr_css_attr_unref(stop);
 229         return false;
 230     }
 231
 232     for (GList const* sel = drag->selected; sel != NULL; sel = sel->next) { // for all selected draggers
 233         GrDragger* dragger = (GrDragger*) sel->data;
 234         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 235                GrDraggable *draggable = (GrDraggable *) i->data;
 236
 237                drag->local_change = true;
 238                sp_item_gradient_stop_set_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke, stop);
 239         }
 240     }
 241
 242     //sp_repr_css_print(stop);
 243     sp_repr_css_attr_unref(stop);
 244     return true;
 245 }
 246
 247 GrDrag::GrDrag(SPDesktop *desktop) {
 248
 249     this->desktop = desktop;
 250
 251     this->selection = sp_desktop_selection(desktop);
 252
 253     this->draggers = NULL;
 254     this->lines = NULL;
 255     this->selected = NULL;
 256
 257     this->hor_levels.clear();
 258     this->vert_levels.clear();
 259
 260     this->local_change = false;
 261
 262     this->sel_changed_connection = this->selection->connectChanged(
 263         sigc::bind (
 264             sigc::ptr_fun(&gr_drag_sel_changed),
 265             (gpointer)this )
 266
 267         );
 268     this->sel_modified_connection = this->selection->connectModified(
 269         sigc::bind(
 270             sigc::ptr_fun(&gr_drag_sel_modified),
 271             (gpointer)this )
 272         );
 273
 274     this->style_set_connection = this->desktop->connectSetStyle(
 275         sigc::bind(
 276             sigc::ptr_fun(&gr_drag_style_set),
 277             (gpointer)this )
 278         );
 279
 280     this->style_query_connection = this->desktop->connectQueryStyle(
 281         sigc::bind(
 282             sigc::ptr_fun(&gr_drag_style_query),
 283             (gpointer)this )
 284         );
 285
 286     this->updateDraggers ();
 287     this->updateLines ();
 288     this->updateLevels ();
 289
 290     if (desktop->gr_item) {
 291         this->setSelected (getDraggerFor (desktop->gr_item, desktop->gr_point_type, desktop->gr_point_i, desktop->gr_fill_or_stroke));
 292     }
 293 }
 294
 295 GrDrag::~GrDrag()
 296 {
 297     this->sel_changed_connection.disconnect();
 298     this->sel_modified_connection.disconnect();
 299     this->style_set_connection.disconnect();
 300     this->style_query_connection.disconnect();
 301
 302     if (this->selected) {
 303         GrDraggable *draggable = (GrDraggable *)   ((GrDragger*)this->selected->data)->draggables->data;
 304         desktop->gr_item = draggable->item;
 305         desktop->gr_point_type = draggable->point_type;
 306         desktop->gr_point_i = draggable->point_i;
 307         desktop->gr_fill_or_stroke = draggable->fill_or_stroke;
 308     } else {
 309         desktop->gr_item = NULL;
 310         desktop->gr_point_type = 0;
 311         desktop->gr_point_i = 0;
 312         desktop->gr_fill_or_stroke = true;
 313     }
 314
 315     deselect_all();
 316     for (GList *l = this->draggers; l != NULL; l = l->next) {
 317         delete ((GrDragger *) l->data);
 318     }
 319     g_list_free (this->draggers);
 320     this->draggers = NULL;
 321     this->selected = NULL;
 322
 323     for (GSList *l = this->lines; l != NULL; l = l->next) {
 324         gtk_object_destroy( GTK_OBJECT (l->data));
 325     }
 326     g_slist_free (this->lines);
 327     this->lines = NULL;
 328 }
 329
 330 GrDraggable::GrDraggable (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke)
 331 {
 332     this->item = item;
 333     this->point_type = point_type;
 334     this->point_i = point_i;
 335     this->fill_or_stroke = fill_or_stroke;
 336
 337     g_object_ref (G_OBJECT (this->item));
 338 }
 339
 340 GrDraggable::~GrDraggable ()
 341 {
 342     g_object_unref (G_OBJECT (this->item));
 343 }
 344
 345 // FIXME: make global function in libnr or somewhere.
 346 static NR::Point *
 347 get_snap_vector (NR::Point p, NR::Point o, double snap, double initial)
 348 {
 349     double r = NR::L2 (p - o);
 350     if (r < 1e-3)
 351         return NULL;
 352     double angle = NR::atan2 (p - o);
 353     // snap angle to snaps increments, starting from initial:
 354     double a_snapped = initial + floor((angle - initial)/snap + 0.5) * snap;
 355     // calculate the new position and subtract p to get the vector:
 356     return new NR::Point (o + r * NR::Point(cos(a_snapped), sin(a_snapped)) - p);
 357 }
 358
 359 // FIXME: make global function in libnr or somewhere.
 360 static NR::Point
 361 snap_vector_midpoint (NR::Point p, NR::Point begin, NR::Point end, double snap)
 362 {
 363     double length = NR::L2(end - begin);
 364     NR::Point be = (end - begin) / length;
 365     double r = NR::dot(p - begin, be);
 366
 367     if (r < 0.0) return begin;
 368     if (r > length) return end;
 369
 370     double snapdist = length * snap;
 371     double r_snapped = (snap==0) ? r : floor(r/(snapdist + 0.5)) * snapdist;
 372
 373     return (begin + r_snapped * be);
 374 }
 375
 376 static void
 377 gr_knot_moved_handler(SPKnot *knot, NR::Point const *ppointer, guint state, gpointer data)
 378 {
 379     GrDragger *dragger = (GrDragger *) data;
 380     GrDrag *drag = dragger->parent;
 381
 382     NR::Point p = *ppointer;
 383
 384     // FIXME: take from prefs
 385     double snap_dist = SNAP_DIST / dragger->parent->desktop->current_zoom();
 386
 387     if (state & GDK_SHIFT_MASK) {
 388         // with Shift; unsnap if we carry more than one draggable
 389         if (dragger->draggables && dragger->draggables->next) {
 390             // create a new dragger
 391             GrDragger *dr_new = new GrDragger (dragger->parent, dragger->point, NULL);
 392             dragger->parent->draggers = g_list_prepend (dragger->parent->draggers, dr_new);
 393             // relink to it all but the first draggable in the list
 394             for (GSList const* i = dragger->draggables->next; i != NULL; i = i->next) {
 395                 GrDraggable *draggable = (GrDraggable *) i->data;
 396                 dr_new->addDraggable (draggable);
 397             }
 398             dr_new->updateKnotShape();
 399             g_slist_free (dragger->draggables->next);
 400             dragger->draggables->next = NULL;
 401             dragger->updateKnotShape();
 402             dragger->updateTip();
 403         }
 404     } else if (!(state & GDK_CONTROL_MASK)) {
 405         // without Shift or Ctrl; see if we need to snap to another dragger
 406         for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 407             GrDragger *d_new = (GrDragger *) di->data;
 408             if (dragger->mayMerge(d_new) && NR::L2 (d_new->point - p) < snap_dist) {
 409
 410                 // Merge draggers:
 411                 for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 412                     GrDraggable *draggable = (GrDraggable *) i->data;
 413                     // copy draggable to d_new:
 414                     GrDraggable *da_new = new GrDraggable (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 415                     d_new->addDraggable (da_new);
 416                 }
 417
 418                 // unlink and delete this dragger
 419                 dragger->parent->draggers = g_list_remove (dragger->parent->draggers, dragger);
 420                 delete dragger;
 421
 422                 // update the new merged dragger
 423                 d_new->fireDraggables(true, false, true);
 424                 d_new->parent->updateLines();
 425                 d_new->parent->setSelected (d_new);
 426                 d_new->updateKnotShape ();
 427                 d_new->updateTip ();
 428                 d_new->updateDependencies(true);
 429                 sp_document_done (sp_desktop_document (d_new->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 430                                   _("Merge gradient handles"));
 431                 return;
 432             }
 433         }
 434     }
 435
 436     if (!((state & GDK_SHIFT_MASK) || ((state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK)))) {
 437         // Try snapping to the grid or guides
 438         SnapManager const &m = dragger->parent->desktop->namedview->snap_manager;
 439         Inkscape::SnappedPoint s = m.freeSnap(Inkscape::Snapper::SNAPPOINT_NODE, p, NULL);
 440         if (s.getDistance() < 1e6) {
 441             p = s.getPoint();
 442             sp_knot_moveto (knot, &p);
 443         } else {
 444             // No snapping so far, let's see if we need to snap to any of the levels
 445             for (guint i = 0; i < dragger->parent->hor_levels.size(); i++) {
 446                 if (fabs(p[NR::Y] - dragger->parent->hor_levels[i]) < snap_dist) {
 447                     p[NR::Y] = dragger->parent->hor_levels[i];
 448                     sp_knot_moveto (knot, &p);
 449                 }
 450             }
 451             for (guint i = 0; i < dragger->parent->vert_levels.size(); i++) {
 452                 if (fabs(p[NR::X] - dragger->parent->vert_levels[i]) < snap_dist) {
 453                     p[NR::X] = dragger->parent->vert_levels[i];
 454                     sp_knot_moveto (knot, &p);
 455                 }
 456             }
 457         }
 458     }
 459
 460     if (state & GDK_CONTROL_MASK) {
 461         unsigned snaps = abs(prefs_get_int_attribute("options.rotationsnapsperpi", "value", 12));
 462         /* 0 means no snapping. */
 463
 464         // This list will store snap vectors from all draggables of dragger
 465         GSList *snap_vectors = NULL;
 466
 467         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) {
 468             GrDraggable *draggable = (GrDraggable *) i->data;
 469
 470             NR::Point *dr_snap = NULL;
 471
 472             if (draggable->point_type == POINT_LG_BEGIN || draggable->point_type == POINT_LG_END) {
 473                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 474                     GrDragger *d_new = (GrDragger *) di->data;
 475                     if (d_new == dragger)
 476                         continue;
 477                     if (d_new->isA (draggable->item,
 478                                     draggable->point_type == POINT_LG_BEGIN? POINT_LG_END : POINT_LG_BEGIN,
 479                                     draggable->point_i,
 480                                     draggable->fill_or_stroke)) {
 481                         // found the other end of the linear gradient;
 482                         if (state & GDK_SHIFT_MASK) {
 483                             // moving linear around center
 484                             NR::Point center = NR::Point (0.5*(d_new->point + dragger->point));
 485                             dr_snap = &center;
 486                         } else {
 487                             // moving linear around the other end
 488                             dr_snap = &d_new->point;
 489                         }
 490                     }
 491                 }
 492             } else if (draggable->point_type == POINT_RG_R1 || draggable->point_type == POINT_RG_R2 || draggable->point_type == POINT_RG_FOCUS) {
 493                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 494                     GrDragger *d_new = (GrDragger *) di->data;
 495                     if (d_new == dragger)
 496                         continue;
 497                     if (d_new->isA (draggable->item,
 498                                     POINT_RG_CENTER,
 499                                     draggable->point_i,
 500                                     draggable->fill_or_stroke)) {
 501                         // found the center of the radial gradient;
 502                         dr_snap = &(d_new->point);
 503                     }
 504                 }
 505             } else if (draggable->point_type == POINT_RG_CENTER) {
 506                 // radial center snaps to hor/vert relative to its original position
 507                 dr_snap = &(dragger->point_original);
 508             }
 509
 510             NR::Point *snap_vector = NULL;
 511             if (dr_snap) {
 512                 if (state & GDK_MOD1_MASK) {
 513                     // with Alt, snap to the original angle and its perpendiculars
 514                     snap_vector = get_snap_vector (p, *dr_snap, M_PI/2, NR::atan2 (dragger->point_original - *dr_snap));
 515                 } else {
 516                     // with Ctrl, snap to M_PI/snaps
 517                     snap_vector = get_snap_vector (p, *dr_snap, M_PI/snaps, 0);
 518                 }
 519             }
 520             if (snap_vector) {
 521                 snap_vectors = g_slist_prepend (snap_vectors, snap_vector);
 522             }
 523         }
 524
 525         // Move by the smallest of snap vectors:
 526         NR::Point move(9999, 9999);
 527         for (GSList const *i = snap_vectors; i != NULL; i = i->next) {
 528             NR::Point *snap_vector = (NR::Point *) i->data;
 529             if (NR::L2(*snap_vector) < NR::L2(move))
 530                 move = *snap_vector;
 531         }
 532         if (move[NR::X] < 9999) {
 533             p += move;
 534             sp_knot_moveto (knot, &p);
 535         }
 536
 537         g_slist_free(snap_vectors);
 538     }
 539
 540     drag->keep_selection = (bool) g_list_find(drag->selected, dragger);
 541     bool scale_radial = (state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK);
 542
 543     if (drag->keep_selection) {
 544         NR::Point diff = p - dragger->point;
 545         drag->selected_move_nowrite (diff[NR::X], diff[NR::Y], scale_radial);
 546     } else {
 547         dragger->point = p;
 548         dragger->fireDraggables (false, scale_radial);
 549         dragger->updateDependencies(false);
 550     }
 551
 552 }
 553
 554
 555 /**
 556 Called when a midpoint knot is dragged.
 557 */
 558 static void
 559 gr_knot_moved_midpoint_handler(SPKnot *knot, NR::Point const *ppointer, guint state, gpointer data)
 560 {
 561     GrDragger *dragger = (GrDragger *) data;
 562     GrDrag *drag = dragger->parent;
 563     // a midpoint dragger can (logically) only contain one GrDraggable
 564     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 565
 566     // FIXME: take from prefs
 567     double snap_fraction = 0.1;
 568
 569     NR::Point p = *ppointer;
 570     NR::Point begin(0,0), end(0,0);
 571
 572     SPObject *server;
 573     if (draggable->fill_or_stroke)
 574         server = SP_OBJECT_STYLE_FILL_SERVER (draggable->item);
 575     else
 576         server = SP_OBJECT_STYLE_STROKE_SERVER (draggable->item);
 577
 578
 579     // get begin and end points between which dragging is allowed:
 580     // the draglimits are between knot(lowest_i - 1) and knot(highest_i + 1)
 581     GSList *moving = NULL;
 582     moving = g_slist_append(moving, dragger);
 583
 584     guint lowest_i = draggable->point_i;
 585     guint highest_i = draggable->point_i;
 586     GrDragger *lowest_dragger = dragger;
 587     GrDragger *highest_dragger = dragger;
 588     bool is_selected = g_list_find(drag->selected, dragger);
 589     if (is_selected) {
 590         GrDragger* d_add;
 591         while ( true )
 592         {
 593             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 594             if ( d_add && g_list_find(drag->selected, d_add) ) {
 595                 lowest_i = lowest_i - 1;
 596                 moving = g_slist_prepend(moving, d_add);
 597                 lowest_dragger = d_add;
 598             } else {
 599                 break;
 600             }
 601         }
 602
 603         while ( true )
 604         {
 605             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 606             if ( d_add && g_list_find(drag->selected, d_add) ) {
 607                 highest_i = highest_i + 1;
 608                 moving = g_slist_append(moving, d_add);
 609                 highest_dragger = d_add;
 610             } else {
 611                 break;
 612             }
 613         }
 614     }
 615
 616     if ( SP_IS_LINEARGRADIENT(server) ) {
 617         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) begin = d_temp->point;
 624
 625         d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, highest_i + 1, draggable->fill_or_stroke);
 626         if (d_temp == NULL) {
 627             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_END, 0, draggable->fill_or_stroke);
 628         }
 629         if (d_temp) end = d_temp->point;
 630     } else if ( SP_IS_RADIALGRADIENT(server) ) {
 631         GrDragger *d_temp;
 632         if (lowest_i == 1) {
 633             d_temp = drag->getDraggerFor (draggable->item, POINT_RG_CENTER, 0, draggable->fill_or_stroke);
 634         } else {
 635             d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 636         }
 637         if (d_temp) begin = d_temp->point;
 638
 639         d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 640         if (d_temp == NULL) {
 641             d_temp = drag->getDraggerFor (draggable->item, (draggable->point_type==POINT_RG_MID1) ? POINT_RG_R1 : POINT_RG_R2, 0, draggable->fill_or_stroke);
 642         }
 643         if (d_temp) end = d_temp->point;
 644     }
 645
 646     NR::Point low_lim  = dragger->point - (lowest_dragger->point - begin);
 647     NR::Point high_lim = dragger->point - (highest_dragger->point - end);
 648
 649     if (state & GDK_CONTROL_MASK) {
 650         p = snap_vector_midpoint (p, low_lim, high_lim, snap_fraction);
 651     } else {
 652         p = snap_vector_midpoint (p, low_lim, high_lim, 0);
 653     }
 654     NR::Point displacement = p - dragger->point;
 655
 656     for (GSList const* i = moving; i != NULL; i = i->next) {
 657         GrDragger *drg = (GrDragger*) i->data;
 658         SPKnot *drgknot = drg->knot;
 659         drg->point += displacement;
 660         sp_knot_moveto (drgknot, & drg->point);
 661         drg->fireDraggables (false);
 662         drg->updateDependencies(false);
 663     }
 664
 665     drag->keep_selection = is_selected;
 666 }
 667
 668
 669
 670 static void
 671 gr_knot_grabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 672 {
 673     GrDragger *dragger = (GrDragger *) data;
 674
 675     sp_canvas_force_full_redraw_after_interruptions(dragger->parent->desktop->canvas, 5);
 676 }
 677
 678 /**
 679 Called when the mouse releases a dragger knot; changes gradient writing to repr, updates other draggers if needed
 680 */
 681 static void
 682 gr_knot_ungrabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 683 {
 684     GrDragger *dragger = (GrDragger *) data;
 685
 686     sp_canvas_end_forced_full_redraws(dragger->parent->desktop->canvas);
 687
 688     dragger->point_original = dragger->point = knot->pos;
 689
 690     if ((state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK)) {
 691         dragger->fireDraggables (true, true);
 692     } else {
 693         dragger->fireDraggables (true);
 694     }
 695
 696     // make this dragger selected
 697     if (!dragger->parent->keep_selection) {
 698         dragger->parent->setSelected (dragger);
 699     }
 700     dragger->parent->keep_selection = false;
 701
 702     dragger->updateDependencies(true);
 703
 704     // we did an undoable action
 705     sp_document_done (sp_desktop_document (dragger->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 706                       _("Move gradient handle"));
 707 }
 708
 709 /**
 710 Called when a dragger knot is clicked; selects the dragger or deletes it depending on the
 711 state of the keyboard keys
 712 */
 713 static void
 714 gr_knot_clicked_handler(SPKnot *knot, guint state, gpointer data)
 715 {
 716     GrDragger *dragger = (GrDragger *) data;
 717     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 718     if (!draggable) return;
 719
 720     if ( (state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK ) ) {
 721     // delete this knot from vector
 722         SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
 723         gradient = sp_gradient_get_vector (gradient, false);
 724         if (gradient->vector.stops.size() > 2) { // 2 is the minimum
 725                 SPStop *stop = NULL;
 726                 switch (draggable->point_type) {  // if we delete first or last stop, move the next/previous to the edge
 727                 case POINT_LG_BEGIN:
 728                 case POINT_RG_CENTER:
 729                     stop = sp_first_stop(gradient);
 730                         {
 731                             SPStop *next = sp_next_stop (stop);
 732                                 if (next) {
 733                                         next->offset = 0;
 734                                         sp_repr_set_css_double (SP_OBJECT_REPR (next), "offset", 0);
 735                                 }
 736                         }
 737                     break;
 738                 case POINT_LG_END:
 739                 case POINT_RG_R1:
 740                 case POINT_RG_R2:
 741                     stop = sp_last_stop(gradient);
 742                     {
 743                             SPStop *prev = sp_prev_stop (stop, gradient);
 744                             if (prev) {
 745                                     prev->offset = 1;
 746                                     sp_repr_set_css_double (SP_OBJECT_REPR (prev), "offset", 1);
 747                             }
 748                         }
 749                     break;
 750                 case POINT_LG_MID:
 751                 case POINT_RG_MID1:
 752                 case POINT_RG_MID2:
 753                     stop = sp_get_stop_i(gradient, draggable->point_i);
 754                     break;
 755                 }
 756
 757                 SP_OBJECT_REPR(gradient)->removeChild(SP_OBJECT_REPR(stop));
 758                 sp_document_done (SP_OBJECT_DOCUMENT (gradient), SP_VERB_CONTEXT_GRADIENT,
 759                                   _("Delete gradient stop"));
 760         }
 761     } else {
 762     // select the dragger
 763         dragger->point_original = dragger->point;
 764
 765         if ( state & GDK_SHIFT_MASK ) {
 766             dragger->parent->setSelected (dragger, true, false);
 767         } else {
 768             dragger->parent->setSelected (dragger);
 769         }
 770     }
 771 }
 772
 773 /**
 774 Called when a dragger knot is doubleclicked; opens gradient editor with the stop from the first draggable
 775 */
 776 static void
 777 gr_knot_doubleclicked_handler (SPKnot *knot, guint state, gpointer data)
 778 {
 779     GrDragger *dragger = (GrDragger *) data;
 780
 781     dragger->point_original = dragger->point;
 782
 783     if (dragger->draggables == NULL)
 784         return;
 785
 786     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 787     sp_item_gradient_edit_stop (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 788 }
 789
 790 /**
 791 Act upon all draggables of the dragger, setting them to the dragger's point
 792 */
 793 void
 794 GrDragger::fireDraggables (bool write_repr, bool scale_radial, bool merging_focus)
 795 {
 796     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 797         GrDraggable *draggable = (GrDraggable *) i->data;
 798
 799         // set local_change flag so that selection_changed callback does not regenerate draggers
 800         this->parent->local_change = true;
 801
 802         // change gradient, optionally writing to repr; prevent focus from moving if it's snapped
 803         // to the center, unless it's the first update upon merge when we must snap it to the point
 804         if (merging_focus ||
 805             !(draggable->point_type == POINT_RG_FOCUS && this->isA(draggable->item, POINT_RG_CENTER, draggable->point_i, draggable->fill_or_stroke)))
 806         {
 807             sp_item_gradient_set_coords (draggable->item, draggable->point_type, draggable->point_i, this->point, draggable->fill_or_stroke, write_repr, scale_radial);
 808         }
 809     }
 810 }
 811
 812 /**
 813 Checks if the dragger has a draggable with this point_type
 814  */
 815 bool
 816 GrDragger::isA (guint point_type)
 817 {
 818     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 819         GrDraggable *draggable = (GrDraggable *) i->data;
 820         if (draggable->point_type == point_type) {
 821             return true;
 822         }
 823     }
 824     return false;
 825 }
 826
 827 /**
 828 Checks if the dragger has a draggable with this item, point_type, fill_or_stroke
 829  */
 830 bool
 831 GrDragger::isA (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke)
 832 {
 833     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 834         GrDraggable *draggable = (GrDraggable *) i->data;
 835         if ( (draggable->point_type == point_type) && (draggable->point_i == point_i) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
 836             return true;
 837         }
 838     }
 839     return false;
 840 }
 841
 842 bool
 843 GrDraggable::mayMerge (GrDraggable *da2)
 844 {
 845     if ((this->item == da2->item) && (this->fill_or_stroke == da2->fill_or_stroke)) {
 846         // we must not merge the points of the same gradient!
 847         if (!((this->point_type == POINT_RG_FOCUS && da2->point_type == POINT_RG_CENTER) ||
 848               (this->point_type == POINT_RG_CENTER && da2->point_type == POINT_RG_FOCUS))) {
 849             // except that we can snap center and focus together
 850             return false;
 851         }
 852     }
 853     // disable merging of midpoints.
 854     if ( (this->point_type == POINT_LG_MID) || (da2->point_type == POINT_LG_MID)
 855          || (this->point_type == POINT_RG_MID1) || (da2->point_type == POINT_RG_MID1)
 856          || (this->point_type == POINT_RG_MID2) || (da2->point_type == POINT_RG_MID2) )
 857         return false;
 858
 859     return true;
 860 }
 861
 862 bool
 863 GrDragger::mayMerge (GrDragger *other)
 864 {
 865     if (this == other)
 866         return false;
 867
 868     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
 869         GrDraggable *da1 = (GrDraggable *) i->data;
 870         for (GSList const* j = other->draggables; j != NULL; j = j->next) { // for all draggables of other
 871             GrDraggable *da2 = (GrDraggable *) j->data;
 872             if (!da1->mayMerge(da2))
 873                 return false;
 874         }
 875     }
 876     return true;
 877 }
 878
 879 bool
 880 GrDragger::mayMerge (GrDraggable *da2)
 881 {
 882     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
 883         GrDraggable *da1 = (GrDraggable *) i->data;
 884         if (!da1->mayMerge(da2))
 885             return false;
 886     }
 887     return true;
 888 }
 889
 890 /**
 891 Updates the statusbar tip of the dragger knot, based on its draggables
 892  */
 893 void
 894 GrDragger::updateTip ()
 895 {
 896         if (this->knot && this->knot->tip) {
 897                 g_free (this->knot->tip);
 898                 this->knot->tip = NULL;
 899         }
 900
 901     if (g_slist_length (this->draggables) == 1) {
 902         GrDraggable *draggable = (GrDraggable *) this->draggables->data;
 903         char *item_desc = sp_item_description(draggable->item);
 904         switch (draggable->point_type) {
 905             case POINT_LG_MID:
 906             case POINT_RG_MID1:
 907             case POINT_RG_MID2:
 908                 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"),
 909                                                    _(gr_knot_descr[draggable->point_type]),
 910                                                    draggable->point_i,
 911                                                    item_desc,
 912                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
 913                 break;
 914
 915             default:
 916                 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"),
 917                                                    _(gr_knot_descr[draggable->point_type]),
 918                                                    item_desc,
 919                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
 920                 break;
 921         }
 922         g_free(item_desc);
 923     } else if (g_slist_length (draggables) == 2 && isA (POINT_RG_CENTER) && isA (POINT_RG_FOCUS)) {
 924         this->knot->tip = g_strdup_printf (_("Radial gradient <b>center</b> and <b>focus</b>; drag with <b>Shift</b> to separate focus"));
 925     } else {
 926         int length = g_slist_length (this->draggables);
 927         this->knot->tip = g_strdup_printf (ngettext("Gradient point shared by <b>%d</b> gradient; drag with <b>Shift</b> to separate",
 928                                                     "Gradient point shared by <b>%d</b> gradients; drag with <b>Shift</b> to separate",
 929                                                     length),
 930                                            length);
 931     }
 932 }
 933
 934 /**
 935 Adds a draggable to the dragger
 936  */
 937 void
 938 GrDragger::updateKnotShape ()
 939 {
 940     if (!draggables)
 941         return;
 942     GrDraggable *last = (GrDraggable *) g_slist_last(draggables)->data;
 943     g_object_set (G_OBJECT (this->knot->item), "shape", gr_knot_shapes[last->point_type], NULL);
 944 }
 945
 946 /**
 947 Adds a draggable to the dragger
 948  */
 949 void
 950 GrDragger::addDraggable (GrDraggable *draggable)
 951 {
 952     this->draggables = g_slist_prepend (this->draggables, draggable);
 953
 954     this->updateTip();
 955 }
 956
 957
 958 /**
 959 Moves this dragger to the point of the given draggable, acting upon all other draggables
 960  */
 961 void
 962 GrDragger::moveThisToDraggable (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke, bool write_repr)
 963 {
 964     this->point = sp_item_gradient_get_coords (item, point_type, point_i, fill_or_stroke);
 965     this->point_original = this->point;
 966
 967     sp_knot_moveto (this->knot, &(this->point));
 968
 969     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 970         GrDraggable *da = (GrDraggable *) i->data;
 971         if ( (da->item == item) && (da->point_type == point_type) && (da->point_i == point_i) && (da->fill_or_stroke == fill_or_stroke) ) {
 972             continue;
 973         }
 974         sp_item_gradient_set_coords (da->item, da->point_type, da->point_i, this->point, da->fill_or_stroke, write_repr, false);
 975     }
 976     // FIXME: here we should also call this->updateDependencies(write_repr); to propagate updating, but how to prevent loops?
 977 }
 978
 979
 980 /**
 981 Moves all midstop draggables that depend on this one
 982  */
 983 void
 984 GrDragger::updateMidstopDependencies (GrDraggable *draggable, bool write_repr) {
 985     SPObject *server;
 986     if (draggable->fill_or_stroke)
 987         server = SP_OBJECT_STYLE_FILL_SERVER (draggable->item);
 988     else
 989         server = SP_OBJECT_STYLE_STROKE_SERVER (draggable->item);
 990     guint num = SP_GRADIENT(server)->vector.stops.size();
 991     if (num <= 2) return;
 992
 993     if ( SP_IS_LINEARGRADIENT(server) ) {
 994         for ( guint i = 1; i < num - 1; i++ ) {
 995             this->moveOtherToDraggable (draggable->item, POINT_LG_MID, i, draggable->fill_or_stroke, write_repr);
 996         }
 997     } else  if ( SP_IS_RADIALGRADIENT(server) ) {
 998         for ( guint i = 1; i < num - 1; i++ ) {
 999             this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, i, draggable->fill_or_stroke, write_repr);
1000             this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, i, draggable->fill_or_stroke, write_repr);
1001         }
1002     }
1003 }
1004
1005
1006 /**
1007 Moves all draggables that depend on this one
1008  */
1009 void
1010 GrDragger::updateDependencies (bool write_repr)
1011 {
1012     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1013         GrDraggable *draggable = (GrDraggable *) i->data;
1014         switch (draggable->point_type) {
1015             case POINT_LG_BEGIN:
1016                 {
1017                     // the end point is dependent only when dragging with ctrl+shift
1018                     this->moveOtherToDraggable (draggable->item, POINT_LG_END, 0, draggable->fill_or_stroke, write_repr);
1019
1020                     this->updateMidstopDependencies (draggable, write_repr);
1021                 }
1022                 break;
1023             case POINT_LG_END:
1024                 {
1025                     // the begin point is dependent only when dragging with ctrl+shift
1026                     this->moveOtherToDraggable (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke, write_repr);
1027
1028                     this->updateMidstopDependencies (draggable, write_repr);
1029                 }
1030                 break;
1031             case POINT_LG_MID:
1032                 // no other nodes depend on mid points.
1033                 break;
1034             case POINT_RG_R2:
1035                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, 0, draggable->fill_or_stroke, write_repr);
1036                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, 0, draggable->fill_or_stroke, write_repr);
1037                 this->updateMidstopDependencies (draggable, write_repr);
1038                 break;
1039             case POINT_RG_R1:
1040                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, 0, draggable->fill_or_stroke, write_repr);
1041                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, 0, draggable->fill_or_stroke, write_repr);
1042                 this->updateMidstopDependencies (draggable, write_repr);
1043                 break;
1044             case POINT_RG_CENTER:
1045                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, 0, draggable->fill_or_stroke, write_repr);
1046                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, 0, draggable->fill_or_stroke, write_repr);
1047                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, 0, draggable->fill_or_stroke, write_repr);
1048                 this->updateMidstopDependencies (draggable, write_repr);
1049                 break;
1050             case POINT_RG_FOCUS:
1051                 // nothing can depend on that
1052                 break;
1053             case POINT_RG_MID1:
1054                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, draggable->point_i, draggable->fill_or_stroke, write_repr);
1055                 break;
1056             case POINT_RG_MID2:
1057                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, draggable->point_i, draggable->fill_or_stroke, write_repr);
1058                 break;
1059             default:
1060                 break;
1061         }
1062     }
1063 }
1064
1065
1066
1067 GrDragger::GrDragger (GrDrag *parent, NR::Point p, GrDraggable *draggable)
1068 {
1069     this->draggables = NULL;
1070
1071     this->parent = parent;
1072
1073     this->point = p;
1074     this->point_original = p;
1075
1076     // create the knot
1077     this->knot = sp_knot_new (parent->desktop, NULL);
1078     this->knot->setMode(SP_KNOT_MODE_XOR);
1079     this->knot->setFill(GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_NORMAL);
1080     this->knot->setStroke(0x000000ff, 0x000000ff, 0x000000ff);
1081     sp_knot_update_ctrl(this->knot);
1082
1083     // move knot to the given point
1084     sp_knot_set_position (this->knot, &p, SP_KNOT_STATE_NORMAL);
1085     sp_knot_show (this->knot);
1086
1087     // connect knot's signals
1088     if ( (draggable)  // it can be NULL if a node in unsnapped (eg. focus point unsnapped from center)
1089                        // luckily, midstops never snap to other nodes so are never unsnapped...
1090          && ( (draggable->point_type == POINT_LG_MID)
1091               || (draggable->point_type == POINT_RG_MID1)
1092               || (draggable->point_type == POINT_RG_MID2) ) )
1093     {
1094         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_midpoint_handler), this);
1095     } else {
1096         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_handler), this);
1097     }
1098     g_signal_connect (G_OBJECT (this->knot), "clicked", G_CALLBACK (gr_knot_clicked_handler), this);
1099     g_signal_connect (G_OBJECT (this->knot), "doubleclicked", G_CALLBACK (gr_knot_doubleclicked_handler), this);
1100     g_signal_connect (G_OBJECT (this->knot), "grabbed", G_CALLBACK (gr_knot_grabbed_handler), this);
1101     g_signal_connect (G_OBJECT (this->knot), "ungrabbed", G_CALLBACK (gr_knot_ungrabbed_handler), this);
1102
1103     // add the initial draggable
1104     if (draggable)
1105         this->addDraggable (draggable);
1106     updateKnotShape();
1107 }
1108
1109 GrDragger::~GrDragger ()
1110 {
1111     // unselect if it was selected
1112     this->parent->setDeselected(this);
1113
1114     // disconnect signals
1115     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_moved_handler), this);
1116     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_clicked_handler), this);
1117     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_doubleclicked_handler), this);
1118     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_grabbed_handler), this);
1119     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_ungrabbed_handler), this);
1120
1121     /* unref should call destroy */
1122     g_object_unref (G_OBJECT (this->knot));
1123
1124     // delete all draggables
1125     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1126         delete ((GrDraggable *) i->data);
1127     }
1128     g_slist_free (this->draggables);
1129     this->draggables = NULL;
1130 }
1131
1132 /**
1133 Select the dragger which has the given draggable.
1134 */
1135 GrDragger *
1136 GrDrag::getDraggerFor (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke)
1137 {
1138     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1139         GrDragger *dragger = (GrDragger *) i->data;
1140         for (GSList const* j = dragger->draggables; j != NULL; j = j->next) {
1141             GrDraggable *da2 = (GrDraggable *) j->data;
1142             if ( (da2->item == item) && (da2->point_type == point_type) && (da2->point_i == point_i) && (da2->fill_or_stroke == fill_or_stroke)) {
1143                 return (dragger);
1144             }
1145         }
1146     }
1147     return NULL;
1148 }
1149
1150
1151 void
1152 GrDragger::moveOtherToDraggable (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke, bool write_repr)
1153 {
1154     GrDragger *d = this->parent->getDraggerFor (item, point_type, point_i, fill_or_stroke);
1155     if (d && d !=  this) {
1156         d->moveThisToDraggable (item, point_type, point_i, fill_or_stroke, write_repr);
1157     }
1158 }
1159
1160
1161 /**
1162   Draw this dragger as selected
1163 */
1164 void
1165 GrDragger::select()
1166 {
1167     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_SELECTED;
1168     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_SELECTED, NULL);
1169 }
1170
1171 /**
1172   Draw this dragger as normal (deselected)
1173 */
1174 void
1175 GrDragger::deselect()
1176 {
1177     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_NORMAL;
1178     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_NORMAL, NULL);
1179 }
1180
1181
1182
1183 /**
1184 \brief Deselect all stops/draggers (private)
1185 */
1186 void
1187 GrDrag::deselect_all()
1188 {
1189     while (selected) {
1190         ( (GrDragger*) selected->data)->deselect();
1191         selected = g_list_remove(selected, selected->data);
1192     }
1193 }
1194
1195 /**
1196 \brief Deselect all stops/draggers (public; emits signal)
1197 */
1198 void
1199 GrDrag::deselectAll()
1200 {
1201     deselect_all();
1202     this->desktop->emitToolSubselectionChanged(NULL);
1203 }
1204
1205 /**
1206 \brief Select all stops/draggers (public; emits signal)
1207 */
1208 void
1209 GrDrag::selectAll()
1210 {
1211     for (GList *l = this->draggers; l != NULL; l = l->next) {
1212         GrDragger *d = ((GrDragger *) l->data);
1213         setSelected (d, true, true);
1214     }
1215 }
1216
1217
1218 /**
1219 \brief Select a dragger
1220 \param dragger       The dragger to select
1221 \param add_to_selection   If true, add to selection, otherwise deselect others
1222 \param override      If true, always select this node, otherwise toggle selected status
1223 */
1224 void
1225 GrDrag::setSelected (GrDragger *dragger, bool add_to_selection, bool override)
1226 {
1227     GrDragger *seldragger = NULL;
1228
1229     if (add_to_selection) {
1230         if (!dragger) return;
1231         if (override) {
1232             if (!g_list_find(selected, dragger)) {
1233                 selected = g_list_prepend(selected, dragger);
1234             }
1235             dragger->select();
1236             seldragger = dragger;
1237         } else { // toggle
1238             if (g_list_find(selected, dragger)) {
1239                 selected = g_list_remove(selected, dragger);
1240                 dragger->deselect();
1241                 if (selected) {
1242                     seldragger = (GrDragger*) selected->data; // select the dragger that is first in the list
1243                 }
1244             } else {
1245                 selected = g_list_prepend(selected, dragger);
1246                 dragger->select();
1247                 seldragger = dragger;
1248             }
1249         }
1250     } else {
1251         deselect_all();
1252         if (dragger) {
1253             selected = g_list_prepend(selected, dragger);
1254             dragger->select();
1255             seldragger = dragger;
1256         }
1257     }
1258     if (seldragger) {
1259         this->desktop->emitToolSubselectionChanged((gpointer) seldragger);
1260     }
1261 }
1262
1263 /**
1264 \brief Deselect a dragger
1265 \param dragger       The dragger to deselect
1266 */
1267 void
1268 GrDrag::setDeselected (GrDragger *dragger)
1269 {
1270     if (g_list_find(selected, dragger)) {
1271         selected = g_list_remove(selected, dragger);
1272         dragger->deselect();
1273     }
1274     this->desktop->emitToolSubselectionChanged((gpointer) (selected ? selected->data : NULL ));
1275 }
1276
1277
1278
1279 /**
1280 Create a line from p1 to p2 and add it to the lines list
1281  */
1282 void
1283 GrDrag::addLine (NR::Point p1, NR::Point p2, guint32 rgba)
1284 {
1285     SPCanvasItem *line = sp_canvas_item_new(sp_desktop_controls(this->desktop),
1286                                                             SP_TYPE_CTRLLINE, NULL);
1287     sp_ctrlline_set_coords(SP_CTRLLINE(line), p1, p2);
1288     if (rgba != GR_LINE_COLOR_FILL) // fill is the default, so don't set color for it to speed up redraw
1289         sp_ctrlline_set_rgba32 (SP_CTRLLINE(line), rgba);
1290     sp_canvas_item_show (line);
1291     this->lines = g_slist_append (this->lines, line);
1292 }
1293
1294 /**
1295 If there already exists a dragger within MERGE_DIST of p, add the draggable to it; otherwise create
1296 new dragger and add it to draggers list
1297  */
1298 void
1299 GrDrag::addDragger (GrDraggable *draggable)
1300 {
1301     NR::Point p = sp_item_gradient_get_coords (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
1302
1303     for (GList *i = this->draggers; i != NULL; i = i->next) {
1304         GrDragger *dragger = (GrDragger *) i->data;
1305         if (dragger->mayMerge (draggable) && NR::L2 (dragger->point - p) < MERGE_DIST) {
1306             // distance is small, merge this draggable into dragger, no need to create new dragger
1307             dragger->addDraggable (draggable);
1308             dragger->updateKnotShape();
1309             return;
1310         }
1311     }
1312
1313     GrDragger *new_dragger = new GrDragger(this, p, draggable);
1314     // fixme: draggers should be added AFTER the last one: this way tabbing through them will be from begin to end.
1315     this->draggers = g_list_append (this->draggers, new_dragger);
1316 }
1317
1318 /**
1319 Add draggers for the radial gradient rg on item
1320 */
1321 void
1322 GrDrag::addDraggersRadial (SPRadialGradient *rg, SPItem *item, bool fill_or_stroke)
1323 {
1324     addDragger (new GrDraggable (item, POINT_RG_CENTER, 0, fill_or_stroke));
1325     guint num = rg->vector.stops.size();
1326     if (num > 2) {
1327         for ( guint i = 1; i < num - 1; i++ ) {
1328             addDragger (new GrDraggable (item, POINT_RG_MID1, i, fill_or_stroke));
1329         }
1330     }
1331     addDragger (new GrDraggable (item, POINT_RG_R1, 0, fill_or_stroke));
1332     if (num > 2) {
1333         for ( guint i = 1; i < num - 1; i++ ) {
1334             addDragger (new GrDraggable (item, POINT_RG_MID2, i, fill_or_stroke));
1335         }
1336     }
1337     addDragger (new GrDraggable (item, POINT_RG_R2, 0, fill_or_stroke));
1338     addDragger (new GrDraggable (item, POINT_RG_FOCUS, 0, fill_or_stroke));
1339 }
1340
1341 /**
1342 Add draggers for the linear gradient lg on item
1343 */
1344 void
1345 GrDrag::addDraggersLinear (SPLinearGradient *lg, SPItem *item, bool fill_or_stroke)
1346 {
1347     addDragger (new GrDraggable (item, POINT_LG_BEGIN, 0, fill_or_stroke));
1348     guint num = lg->vector.stops.size();
1349     if (num > 2) {
1350         for ( guint i = 1; i < num - 1; i++ ) {
1351             addDragger (new GrDraggable (item, POINT_LG_MID, i, fill_or_stroke));
1352         }
1353     }
1354     addDragger (new GrDraggable (item, POINT_LG_END, 0, fill_or_stroke));
1355 }
1356
1357 /**
1358 Artificially grab the knot of the dragger with this draggable; used by the gradient context
1359 */
1360 void
1361 GrDrag::grabKnot (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke, gint x, gint y, guint32 etime)
1362 {
1363     GrDragger *dragger = getDraggerFor (item, point_type, point_i, fill_or_stroke);
1364     if (dragger) {
1365         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1366     }
1367 }
1368
1369 /**
1370 Regenerates the draggers list from the current selection; is called when selection is changed or
1371 modified, also when a radial dragger needs to update positions of other draggers in the gradient
1372 */
1373 void
1374 GrDrag::updateDraggers ()
1375 {
1376     while (selected) {
1377         selected = g_list_remove(selected, selected->data);
1378     }
1379     // delete old draggers
1380     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1381         delete ((GrDragger *) i->data);
1382     }
1383     g_list_free (this->draggers);
1384     this->draggers = NULL;
1385
1386     g_return_if_fail (this->selection != NULL);
1387
1388     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1389
1390         SPItem *item = SP_ITEM(i->data);
1391         SPStyle *style = SP_OBJECT_STYLE (item);
1392
1393         if (style && (style->fill.isPaintserver())) {
1394             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1395             if (SP_IS_LINEARGRADIENT (server)) {
1396                 addDraggersLinear (SP_LINEARGRADIENT (server), item, true);
1397             } else if (SP_IS_RADIALGRADIENT (server)) {
1398                 addDraggersRadial (SP_RADIALGRADIENT (server), item, true);
1399             }
1400         }
1401
1402         if (style && (style->stroke.isPaintserver())) {
1403             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1404             if (SP_IS_LINEARGRADIENT (server)) {
1405                 addDraggersLinear (SP_LINEARGRADIENT (server), item, false);
1406             } else if (SP_IS_RADIALGRADIENT (server)) {
1407                 addDraggersRadial (SP_RADIALGRADIENT (server), item, false);
1408             }
1409         }
1410     }
1411 }
1412
1413 /**
1414 Regenerates the lines list from the current selection; is called on each move of a dragger, so that
1415 lines are always in sync with the actual gradient
1416 */
1417 void
1418 GrDrag::updateLines ()
1419 {
1420     // delete old lines
1421     for (GSList const *i = this->lines; i != NULL; i = i->next) {
1422         gtk_object_destroy( GTK_OBJECT (i->data));
1423     }
1424     g_slist_free (this->lines);
1425     this->lines = NULL;
1426
1427     g_return_if_fail (this->selection != NULL);
1428
1429     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1430
1431         SPItem *item = SP_ITEM(i->data);
1432
1433         SPStyle *style = SP_OBJECT_STYLE (item);
1434
1435         if (style && (style->fill.isPaintserver())) {
1436             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1437             if (SP_IS_LINEARGRADIENT (server)) {
1438                 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);
1439             } else if (SP_IS_RADIALGRADIENT (server)) {
1440                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, true);
1441                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, true), GR_LINE_COLOR_FILL);
1442                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, true), GR_LINE_COLOR_FILL);
1443             }
1444         }
1445
1446         if (style && (style->stroke.isPaintserver())) {
1447             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1448             if (SP_IS_LINEARGRADIENT (server)) {
1449                 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);
1450             } else if (SP_IS_RADIALGRADIENT (server)) {
1451                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, false);
1452                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, false), GR_LINE_COLOR_STROKE);
1453                 this->addLine (center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, false), GR_LINE_COLOR_STROKE);
1454             }
1455         }
1456     }
1457 }
1458
1459 /**
1460 Regenerates the levels list from the current selection
1461 */
1462 void
1463 GrDrag::updateLevels ()
1464 {
1465     hor_levels.clear();
1466     vert_levels.clear();
1467
1468     g_return_if_fail (this->selection != NULL);
1469
1470     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1471         SPItem *item = SP_ITEM(i->data);
1472         NR::Maybe<NR::Rect> rect = sp_item_bbox_desktop (item);
1473         if (rect) {
1474             // Remember the edges of the bbox and the center axis
1475             hor_levels.push_back(rect->min()[NR::Y]);
1476             hor_levels.push_back(rect->max()[NR::Y]);
1477             hor_levels.push_back(0.5 * (rect->min()[NR::Y] + rect->max()[NR::Y]));
1478             vert_levels.push_back(rect->min()[NR::X]);
1479             vert_levels.push_back(rect->max()[NR::X]);
1480             vert_levels.push_back(0.5 * (rect->min()[NR::X] + rect->max()[NR::X]));
1481         }
1482     }
1483 }
1484
1485 void
1486 GrDrag::selected_reverse_vector ()
1487 {
1488     if (selected == NULL)
1489         return;
1490
1491     for (GSList const* i = ( (GrDragger*) selected->data )->draggables; i != NULL; i = i->next) {
1492         GrDraggable *draggable = (GrDraggable *) i->data;
1493
1494         sp_item_gradient_reverse_vector (draggable->item, draggable->fill_or_stroke);
1495     }
1496 }
1497
1498 void
1499 GrDrag::selected_move_nowrite (double x, double y, bool scale_radial)
1500 {
1501     selected_move (x, y, false, scale_radial);
1502 }
1503
1504 void
1505 GrDrag::selected_move (double x, double y, bool write_repr, bool scale_radial)
1506 {
1507     if (selected == NULL)
1508         return;
1509
1510     bool did = false;
1511
1512     for (GList *i = selected; i != NULL; i = i->next) {
1513         GrDragger *d = (GrDragger *) i->data;
1514
1515         if (!d->isA(POINT_LG_MID) && !d->isA(POINT_RG_MID1) && !d->isA(POINT_RG_MID2)) {
1516             // if this is a an endpoint,
1517
1518             // Moving an rg center moves its focus and radii as well.
1519             // therefore, if this is a focus or radius and if selection
1520             // contains the center as well, do not move this one
1521             bool skip_radius_with_center = false;
1522             if (d->isA(POINT_RG_R1) || d->isA(POINT_RG_R2) ||
1523                 (d->isA(POINT_RG_FOCUS) && !d->isA(POINT_RG_CENTER))) {
1524                 for (GList *di = selected; di != NULL; di = di->next) {
1525                     GrDragger *d_new = (GrDragger *) di->data;
1526                     if (d_new->isA (((GrDraggable *) d->draggables->data)->item,
1527                                     POINT_RG_CENTER,
1528                                     ((GrDraggable *) d->draggables->data)->point_i,
1529                                     ((GrDraggable *) d->draggables->data)->fill_or_stroke)) {
1530                         // FIXME: here we take into account only the first draggable!
1531                         skip_radius_with_center = true;
1532                     }
1533                 }
1534                 if (skip_radius_with_center)
1535                     continue;
1536             }
1537
1538             did = true;
1539             d->point += NR::Point (x, y);
1540             d->point_original = d->point;
1541             sp_knot_moveto (d->knot, &(d->point));
1542
1543             d->fireDraggables (write_repr, scale_radial);
1544
1545             d->updateDependencies(write_repr);
1546         }
1547     }
1548
1549     if (!did) { // none of the end draggers are selected, so let's try to move the mids
1550         for (GList *i = selected; i != NULL; i = i->next) {
1551             GrDragger *d = (GrDragger *) i->data;
1552
1553             if (d->isA(POINT_LG_MID) || !d->isA(POINT_RG_MID1) || !d->isA(POINT_RG_MID2)) {
1554             }
1555         }
1556     }
1557
1558     if (write_repr && did) {
1559         // we did an undoable action
1560         sp_document_maybe_done (sp_desktop_document (desktop), "grmove", SP_VERB_CONTEXT_GRADIENT,
1561                           _("Move gradient handle"));
1562     }
1563 }
1564
1565 void
1566 GrDrag::selected_move_screen (double x, double y)
1567 {
1568     gdouble zoom = desktop->current_zoom();
1569     gdouble zx = x / zoom;
1570     gdouble zy = y / zoom;
1571
1572     selected_move (zx, zy);
1573 }
1574
1575 /**
1576 Select the knot next to the last selected one and deselect all other selected.
1577 */
1578 void
1579 GrDrag::select_next ()
1580 {
1581     if (selected == NULL || g_list_find(draggers, selected->data)->next == NULL) {
1582         if (draggers)
1583             setSelected ((GrDragger *) draggers->data);
1584     } else {
1585         setSelected ((GrDragger *) g_list_find(draggers, selected->data)->next->data);
1586     }
1587 }
1588
1589 /**
1590 Select the knot previous from the last selected one and deselect all other selected.
1591 */
1592 void
1593 GrDrag::select_prev ()
1594 {
1595     if (selected == NULL || g_list_find(draggers, selected->data)->prev == NULL) {
1596         if (draggers)
1597             setSelected ((GrDragger *) g_list_last (draggers)->data);
1598     } else {
1599         setSelected ((GrDragger *) g_list_find(draggers, selected->data)->prev->data);
1600     }
1601 }
1602
1603
1604 // FIXME: i.m.o. an ugly function that I just made to work, but... aargh! (Johan)
1605 void
1606 GrDrag::deleteSelected (bool just_one)
1607 {
1608     if (!selected) return;
1609
1610     SPDocument *document = false;
1611
1612     struct StructStopInfo {
1613         SPStop * spstop;
1614         GrDraggable * draggable;
1615         SPGradient * gradient;
1616         SPGradient * vector;
1617     };
1618
1619     GSList *midstoplist = NULL;  // list of stops that must be deleted (will be deleted first)
1620     GSList *endstoplist = NULL;  // list of stops that must be deleted
1621     while (selected) {
1622         GrDragger *dragger = (GrDragger*) selected->data;
1623         for (GSList * drgble = dragger->draggables; drgble != NULL; drgble = drgble->next) {
1624             GrDraggable *draggable = (GrDraggable*) drgble->data;
1625             SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
1626             SPGradient *vector   = sp_gradient_get_forked_vector_if_necessary (gradient, false);
1627
1628             switch (draggable->point_type) {
1629                 case POINT_LG_MID:
1630                 case POINT_RG_MID1:
1631                 case POINT_RG_MID2:
1632                     {
1633                         SPStop *stop = sp_get_stop_i(vector, draggable->point_i);
1634                         // check if already present in list. (e.g. when both RG_MID1 and RG_MID2 were selected)
1635                         bool present = false;
1636                         for (GSList const * l = midstoplist; l != NULL; l = l->next) {
1637                             if ( (SPStop*)l->data == stop ) {
1638                                 present = true;
1639                                 break; // no need to search further.
1640                             }
1641                         }
1642                         if (!present)
1643                             midstoplist = g_slist_append(midstoplist, stop);
1644                     }
1645                     break;
1646                 case POINT_LG_BEGIN:
1647                 case POINT_LG_END:
1648                 case POINT_RG_CENTER:
1649                 case POINT_RG_R1:
1650                 case POINT_RG_R2:
1651                     {
1652                         SPStop *stop = NULL;
1653                         if ( (draggable->point_type == POINT_LG_BEGIN) || (draggable->point_type == POINT_RG_CENTER) ) {
1654                             stop = sp_first_stop(vector);
1655                         } else {
1656                             stop = sp_last_stop(vector);
1657                         }
1658                         if (stop) {
1659                             StructStopInfo *stopinfo = new StructStopInfo;
1660                             stopinfo->spstop = stop;
1661                             stopinfo->draggable = draggable;
1662                             stopinfo->gradient = gradient;
1663                             stopinfo->vector = vector;
1664                             // check if already present in list. (e.g. when both R1 and R2 were selected)
1665                             bool present = false;
1666                             for (GSList const * l = endstoplist; l != NULL; l = l->next) {
1667                                 if ( ((StructStopInfo*)l->data)->spstop == stopinfo->spstop ) {
1668                                     present = true;
1669                                     break; // no need to search further.
1670                                 }
1671                             }
1672                             if (!present)
1673                                 endstoplist = g_slist_append(endstoplist, stopinfo);
1674                         }
1675                     }
1676                     break;
1677                 default:
1678                     break;
1679             }
1680         }
1681         selected = g_list_remove(selected, dragger);
1682         if ( just_one ) break; // iterate once if just_one is set.
1683     }
1684     while (midstoplist) {
1685         SPStop *stop = (SPStop*) midstoplist->data;
1686         document = SP_OBJECT_DOCUMENT (stop);
1687         Inkscape::XML::Node * parent = SP_OBJECT_REPR(stop)->parent();
1688         parent->removeChild(SP_OBJECT_REPR(stop));
1689         midstoplist = g_slist_remove(midstoplist, stop);
1690     }
1691     while (endstoplist) {
1692         StructStopInfo *stopinfo  = (StructStopInfo*) endstoplist->data;
1693         document = SP_OBJECT_DOCUMENT (stopinfo->spstop);
1694
1695         // 2 is the minimum, cannot delete more than that without deleting the whole vector
1696         // cannot use vector->vector.stops.size() because the vector might be invalidated by deletion of a midstop
1697         // manually count the children, don't know if there already exists a function for this...
1698         int len = 0;
1699         for ( SPObject *child = sp_object_first_child(stopinfo->vector) ;
1700               child != NULL ;
1701               child = SP_OBJECT_NEXT(child) )
1702         {
1703             if ( SP_IS_STOP(child) )  len ++;
1704         }
1705         if (len > 2)
1706         {
1707             switch (stopinfo->draggable->point_type) {
1708                 case POINT_LG_BEGIN:
1709                     {
1710                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1711
1712                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
1713                         NR::Point oldbegin = NR::Point (lg->x1.computed, lg->y1.computed);
1714                         NR::Point end = NR::Point (lg->x2.computed, lg->y2.computed);
1715                         SPStop *stop = sp_first_stop(stopinfo->vector);
1716                         gdouble offset = stop->offset;
1717                         NR::Point newbegin = oldbegin + offset * (end - oldbegin);
1718                         lg->x1.computed = newbegin[NR::X];
1719                         lg->y1.computed = newbegin[NR::Y];
1720
1721                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
1722                         sp_repr_set_svg_double(repr, "x1", lg->x1.computed);
1723                         sp_repr_set_svg_double(repr, "y1", lg->y1.computed);
1724                         stop->offset = 0;
1725                         sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", 0);
1726
1727                         // iterate through midstops to set new offset values such that they won't move on canvas.
1728                         SPStop *laststop = sp_last_stop(stopinfo->vector);
1729                         stop = sp_next_stop(stop);
1730                         while ( stop != laststop ) {
1731                             stop->offset = (stop->offset - offset)/(1 - offset);
1732                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
1733                             stop = sp_next_stop(stop);
1734                         }
1735                     }
1736                     break;
1737                 case POINT_LG_END:
1738                     {
1739                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1740
1741                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
1742                         NR::Point begin = NR::Point (lg->x1.computed, lg->y1.computed);
1743                         NR::Point oldend = NR::Point (lg->x2.computed, lg->y2.computed);
1744                         SPStop *laststop = sp_last_stop(stopinfo->vector);
1745                         gdouble offset = laststop->offset;
1746                         NR::Point newend = begin + offset * (oldend - begin);
1747                         lg->x2.computed = newend[NR::X];
1748                         lg->y2.computed = newend[NR::Y];
1749
1750                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
1751                         sp_repr_set_svg_double(repr, "x2", lg->x2.computed);
1752                         sp_repr_set_svg_double(repr, "y2", lg->y2.computed);
1753                         laststop->offset = 1;
1754                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
1755
1756                         // iterate through midstops to set new offset values such that they won't move on canvas.
1757                         SPStop *stop = sp_first_stop(stopinfo->vector);
1758                         stop = sp_next_stop(stop);
1759                         while ( stop != laststop ) {
1760                             stop->offset = stop->offset / offset;
1761                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
1762                             stop = sp_next_stop(stop);
1763                         }
1764                     }
1765                     break;
1766                 case POINT_RG_CENTER:
1767                     {
1768                         SPStop *newfirst = sp_next_stop (stopinfo->spstop);
1769                         if (newfirst) {
1770                             newfirst->offset = 0;
1771                             sp_repr_set_css_double (SP_OBJECT_REPR (newfirst), "offset", 0);
1772                         }
1773                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1774                     }
1775                     break;
1776                 case POINT_RG_R1:
1777                 case POINT_RG_R2:
1778                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1779
1780                         SPRadialGradient *rg = SP_RADIALGRADIENT(stopinfo->gradient);
1781                         double oldradius = rg->r.computed;
1782                         SPStop *laststop = sp_last_stop(stopinfo->vector);
1783                         gdouble offset = laststop->offset;
1784                         double newradius = offset * oldradius;
1785                         rg->r.computed = newradius;
1786
1787                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(rg);
1788                         sp_repr_set_svg_double(repr, "r", rg->r.computed);
1789                         laststop->offset = 1;
1790                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
1791
1792                         // iterate through midstops to set new offset values such that they won't move on canvas.
1793                         SPStop *stop = sp_first_stop(stopinfo->vector);
1794                         stop = sp_next_stop(stop);
1795                         while ( stop != laststop ) {
1796                             stop->offset = stop->offset / offset;
1797                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
1798                             stop = sp_next_stop(stop);
1799                         }
1800                         break;
1801             }
1802         }
1803         else
1804         { // delete the gradient from the object. set fill to unset  FIXME: set to fill of unselected node?
1805             SPCSSAttr *css = sp_repr_css_attr_new ();
1806
1807             // stopinfo->spstop is the selected stop
1808             Inkscape::XML::Node *unselectedrepr = SP_OBJECT_REPR(stopinfo->vector)->firstChild();
1809             if (unselectedrepr == SP_OBJECT_REPR(stopinfo->spstop) ) {
1810                 unselectedrepr = unselectedrepr->next();
1811             }
1812
1813             if (unselectedrepr == NULL) {
1814                 if (stopinfo->draggable->fill_or_stroke) {
1815                     sp_repr_css_unset_property (css, "fill");
1816                 } else {
1817                     sp_repr_css_unset_property (css, "stroke");
1818                 }
1819             } else {
1820                 SPCSSAttr *stopcss = sp_repr_css_attr(unselectedrepr, "style");
1821                 if (stopinfo->draggable->fill_or_stroke) {
1822                     sp_repr_css_set_property(css, "fill", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
1823                     sp_repr_css_set_property(css, "fill-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
1824                 } else {
1825                     sp_repr_css_set_property(css, "stroke", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
1826                     sp_repr_css_set_property(css, "stroke-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
1827                 }
1828                 sp_repr_css_attr_unref (stopcss);
1829             }
1830
1831             sp_repr_css_change (SP_OBJECT_REPR (stopinfo->draggable->item), css, "style");
1832             sp_repr_css_attr_unref (css);
1833         }
1834
1835         endstoplist = g_slist_remove(endstoplist, stopinfo);
1836         delete stopinfo;
1837     }
1838
1839     if (document) {
1840         sp_document_done ( document, SP_VERB_CONTEXT_GRADIENT, _("Delete gradient stop(s)") );
1841     }
1842 }
1843
1844
1845 /*
1846   Local Variables:
1847   mode:c++
1848   c-file-style:"stroustrup"
1849   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1850   indent-tabs-mode:nil
1851   fill-column:99
1852   End:
1853 */
1854 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :