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 #include <cstring>
  22 #include <string>
  23
  24 #include "desktop-handles.h"
  25 #include "selection.h"
  26 #include "desktop.h"
  27 #include "desktop-style.h"
  28 #include "document.h"
  29 #include "display/sp-ctrlline.h"
  30 #include "xml/repr.h"
  31 #include "svg/css-ostringstream.h"
  32 #include "svg/svg.h"
  33 #include "libnr/nr-point-fns.h"
  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 #include "snap.h"
  44 #include "sp-namedview.h"
  45 #include "selection-chemistry.h"
  46 #include "display/snap-indicator.h"
  47
  48
  49 #define GR_KNOT_COLOR_NORMAL 0xffffff00
  50 #define GR_KNOT_COLOR_MOUSEOVER 0xff000000
  51 #define GR_KNOT_COLOR_SELECTED 0x0000ff00
  52
  53 #define GR_LINE_COLOR_FILL 0x0000ff7f
  54 #define GR_LINE_COLOR_STROKE 0x9999007f
  55
  56 // screen pixels between knots when they snap:
  57 #define SNAP_DIST 5
  58
  59 // absolute distance between gradient points for them to become a single dragger when the drag is created:
  60 #define MERGE_DIST 0.1
  61
  62 // knot shapes corresponding to GrPointType enum
  63 SPKnotShapeType gr_knot_shapes [] = {
  64         SP_KNOT_SHAPE_SQUARE, //POINT_LG_BEGIN
  65         SP_KNOT_SHAPE_CIRCLE,  //POINT_LG_END
  66         SP_KNOT_SHAPE_DIAMOND, //POINT_LG_MID
  67         SP_KNOT_SHAPE_SQUARE,  // POINT_RG_CENTER
  68         SP_KNOT_SHAPE_CIRCLE,  // POINT_RG_R1
  69         SP_KNOT_SHAPE_CIRCLE,  // POINT_RG_R2
  70         SP_KNOT_SHAPE_CROSS, // POINT_RG_FOCUS
  71         SP_KNOT_SHAPE_DIAMOND, //POINT_RG_MID1
  72         SP_KNOT_SHAPE_DIAMOND //POINT_RG_MID2
  73 };
  74
  75 const gchar *gr_knot_descr [] = {
  76     N_("Linear gradient <b>start</b>"), //POINT_LG_BEGIN
  77     N_("Linear gradient <b>end</b>"),
  78     N_("Linear gradient <b>mid stop</b>"),
  79     N_("Radial gradient <b>center</b>"),
  80     N_("Radial gradient <b>radius</b>"),
  81     N_("Radial gradient <b>radius</b>"),
  82     N_("Radial gradient <b>focus</b>"), // POINT_RG_FOCUS
  83     N_("Radial gradient <b>mid stop</b>"),
  84     N_("Radial gradient <b>mid stop</b>")
  85 };
  86
  87 static void
  88 gr_drag_sel_changed(Inkscape::Selection */*selection*/, gpointer data)
  89 {
  90     GrDrag *drag = (GrDrag *) data;
  91     drag->updateDraggers ();
  92     drag->updateLines ();
  93     drag->updateLevels ();
  94 }
  95
  96 static void
  97 gr_drag_sel_modified (Inkscape::Selection */*selection*/, guint /*flags*/, gpointer data)
  98 {
  99     GrDrag *drag = (GrDrag *) data;
 100     if (drag->local_change) {
 101         drag->local_change = false;
 102     } else {
 103         drag->updateDraggers ();
 104     }
 105     drag->updateLines ();
 106     drag->updateLevels ();
 107 }
 108
 109 /**
 110 When a _query_style_signal is received, check that \a property requests fill/stroke/opacity (otherwise
 111 skip), and fill the \a style with the averaged color of all draggables of the selected dragger, if
 112 any.
 113 */
 114 int
 115 gr_drag_style_query (SPStyle *style, int property, gpointer data)
 116 {
 117     GrDrag *drag = (GrDrag *) data;
 118
 119     if (property != QUERY_STYLE_PROPERTY_FILL && property != QUERY_STYLE_PROPERTY_STROKE && property != QUERY_STYLE_PROPERTY_MASTEROPACITY) {
 120         return QUERY_STYLE_NOTHING;
 121     }
 122
 123     if (!drag->selected) {
 124         return QUERY_STYLE_NOTHING;
 125     } else {
 126         int ret = QUERY_STYLE_NOTHING;
 127
 128         float cf[4];
 129         cf[0] = cf[1] = cf[2] = cf[3] = 0;
 130
 131         int count = 0;
 132
 133         for (GList *i = drag->selected; i != NULL; i = i->next) { // for all selected draggers
 134             GrDragger *d = (GrDragger *) i->data;
 135             for (GSList const* j = d->draggables; j != NULL; j = j->next) { // for all draggables of dragger
 136                 GrDraggable *draggable = (GrDraggable *) j->data;
 137
 138                 if (ret == QUERY_STYLE_NOTHING) {
 139                     ret = QUERY_STYLE_SINGLE;
 140                 } else if (ret == QUERY_STYLE_SINGLE) {
 141                     ret = QUERY_STYLE_MULTIPLE_AVERAGED;
 142                 }
 143
 144                 guint32 c = sp_item_gradient_stop_query_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 145                 cf[0] += SP_RGBA32_R_F (c);
 146                 cf[1] += SP_RGBA32_G_F (c);
 147                 cf[2] += SP_RGBA32_B_F (c);
 148                 cf[3] += SP_RGBA32_A_F (c);
 149
 150                 count ++;
 151             }
 152         }
 153
 154         if (count) {
 155             cf[0] /= count;
 156             cf[1] /= count;
 157             cf[2] /= count;
 158             cf[3] /= count;
 159
 160             // set both fill and stroke with our stop-color and stop-opacity
 161             style->fill.clear();
 162             style->fill.setColor( cf[0], cf[1], cf[2] );
 163             style->fill.set = TRUE;
 164             style->stroke.clear();
 165             style->stroke.setColor( cf[0], cf[1], cf[2] );
 166             style->stroke.set = TRUE;
 167
 168             style->fill_opacity.value = SP_SCALE24_FROM_FLOAT (1.0);
 169             style->fill_opacity.set = TRUE;
 170             style->stroke_opacity.value = SP_SCALE24_FROM_FLOAT (1.0);
 171             style->stroke_opacity.set = TRUE;
 172
 173             style->opacity.value = SP_SCALE24_FROM_FLOAT (cf[3]);
 174             style->opacity.set = TRUE;
 175         }
 176
 177         return ret;
 178     }
 179 }
 180
 181 bool
 182 gr_drag_style_set (const SPCSSAttr *css, gpointer data)
 183 {
 184     GrDrag *drag = (GrDrag *) data;
 185
 186     if (!drag->selected)
 187         return false;
 188
 189     SPCSSAttr *stop = sp_repr_css_attr_new ();
 190
 191     // See if the css contains interesting properties, and if so, translate them into the format
 192     // acceptable for gradient stops
 193
 194     // any of color properties, in order of increasing priority:
 195     if (css->attribute("flood-color"))
 196         sp_repr_css_set_property (stop, "stop-color", css->attribute("flood-color"));
 197
 198     if (css->attribute("lighting-color"))
 199         sp_repr_css_set_property (stop, "stop-color", css->attribute("lighting-color"));
 200
 201     if (css->attribute("color"))
 202         sp_repr_css_set_property (stop, "stop-color", css->attribute("color"));
 203
 204     if (css->attribute("stroke") && strcmp(css->attribute("stroke"), "none"))
 205         sp_repr_css_set_property (stop, "stop-color", css->attribute("stroke"));
 206
 207     if (css->attribute("fill") && strcmp(css->attribute("fill"), "none"))
 208         sp_repr_css_set_property (stop, "stop-color", css->attribute("fill"));
 209
 210     if (css->attribute("stop-color"))
 211         sp_repr_css_set_property (stop, "stop-color", css->attribute("stop-color"));
 212
 213
 214     if (css->attribute("stop-opacity")) { // direct setting of stop-opacity has priority
 215         sp_repr_css_set_property (stop, "stop-opacity", css->attribute("stop-opacity"));
 216     } else {  // multiply all opacity properties:
 217         gdouble accumulated = 1.0;
 218         accumulated *= sp_svg_read_percentage(css->attribute("flood-opacity"), 1.0);
 219         accumulated *= sp_svg_read_percentage(css->attribute("opacity"), 1.0);
 220         accumulated *= sp_svg_read_percentage(css->attribute("stroke-opacity"), 1.0);
 221         accumulated *= sp_svg_read_percentage(css->attribute("fill-opacity"), 1.0);
 222
 223         Inkscape::CSSOStringStream os;
 224         os << accumulated;
 225         sp_repr_css_set_property (stop, "stop-opacity", os.str().c_str());
 226
 227         if ((css->attribute("fill") && !css->attribute("stroke") && !strcmp(css->attribute("fill"), "none")) ||
 228             (css->attribute("stroke") && !css->attribute("fill") && !strcmp(css->attribute("stroke"), "none")))
 229             sp_repr_css_set_property (stop, "stop-opacity", "0"); // if a single fill/stroke property is set to none, don't change color, set opacity to 0
 230     }
 231
 232     if (!stop->attributeList()) { // nothing for us here, pass it on
 233         sp_repr_css_attr_unref(stop);
 234         return false;
 235     }
 236
 237     for (GList const* sel = drag->selected; sel != NULL; sel = sel->next) { // for all selected draggers
 238         GrDragger* dragger = (GrDragger*) sel->data;
 239         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 240                GrDraggable *draggable = (GrDraggable *) i->data;
 241
 242                drag->local_change = true;
 243                sp_item_gradient_stop_set_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke, stop);
 244         }
 245     }
 246
 247     //sp_repr_css_print(stop);
 248     sp_repr_css_attr_unref(stop);
 249     return true;
 250 }
 251
 252 guint32 GrDrag::getColor()
 253 {
 254     if (!selected) return 0;
 255
 256     float cf[4];
 257     cf[0] = cf[1] = cf[2] = cf[3] = 0;
 258
 259     int count = 0;
 260
 261     for (GList *i = selected; i != NULL; i = i->next) { // for all selected draggers
 262         GrDragger *d = (GrDragger *) i->data;
 263         for (GSList const* j = d->draggables; j != NULL; j = j->next) { // for all draggables of dragger
 264             GrDraggable *draggable = (GrDraggable *) j->data;
 265
 266             guint32 c = sp_item_gradient_stop_query_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 267             cf[0] += SP_RGBA32_R_F (c);
 268             cf[1] += SP_RGBA32_G_F (c);
 269             cf[2] += SP_RGBA32_B_F (c);
 270             cf[3] += SP_RGBA32_A_F (c);
 271
 272             count ++;
 273         }
 274     }
 275
 276     if (count) {
 277         cf[0] /= count;
 278         cf[1] /= count;
 279         cf[2] /= count;
 280         cf[3] /= count;
 281     }
 282
 283     return SP_RGBA32_F_COMPOSE(cf[0], cf[1], cf[2], cf[3]);
 284 }
 285
 286 SPStop *
 287 GrDrag::addStopNearPoint (SPItem *item, NR::Point mouse_p, double tolerance)
 288 {
 289     gfloat offset; // type of SPStop.offset = gfloat
 290     SPGradient *gradient;
 291     bool fill_or_stroke = true;
 292     bool r1_knot = false;
 293
 294     bool addknot = false;
 295     do {
 296         gradient = sp_item_gradient (item, fill_or_stroke);
 297         if (SP_IS_LINEARGRADIENT(gradient)) {
 298             NR::Point begin   = sp_item_gradient_get_coords(item, POINT_LG_BEGIN, 0, fill_or_stroke);
 299             NR::Point end     = sp_item_gradient_get_coords(item, POINT_LG_END, 0, fill_or_stroke);
 300
 301             NR::Point nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 302             double dist_screen = NR::L2 (mouse_p - nearest);
 303             if ( dist_screen < tolerance ) {
 304                 // add the knot
 305                 offset = get_offset_between_points(nearest, begin, end);
 306                 addknot = true;
 307                 break; // break out of the while loop: add only one knot
 308             }
 309         } else if (SP_IS_RADIALGRADIENT(gradient)) {
 310             NR::Point begin = sp_item_gradient_get_coords(item, POINT_RG_CENTER, 0, fill_or_stroke);
 311             NR::Point end   = sp_item_gradient_get_coords(item, POINT_RG_R1, 0, fill_or_stroke);
 312             NR::Point nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 313             double dist_screen = NR::L2 (mouse_p - nearest);
 314             if ( dist_screen < tolerance ) {
 315                 offset = get_offset_between_points(nearest, begin, end);
 316                 addknot = true;
 317                 r1_knot = true;
 318                 break; // break out of the while loop: add only one knot
 319             }
 320
 321             end    = sp_item_gradient_get_coords(item, POINT_RG_R2, 0, fill_or_stroke);
 322             nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 323             dist_screen = NR::L2 (mouse_p - nearest);
 324             if ( dist_screen < tolerance ) {
 325                 offset = get_offset_between_points(nearest, begin, end);
 326                 addknot = true;
 327                 r1_knot = false;
 328                 break; // break out of the while loop: add only one knot
 329             }
 330         }
 331         fill_or_stroke = !fill_or_stroke;
 332     } while (!fill_or_stroke && !addknot) ;
 333
 334     if (addknot) {
 335         SPGradient *vector = sp_gradient_get_forked_vector_if_necessary (gradient, false);
 336         SPStop* prev_stop = sp_first_stop(vector);
 337         SPStop* next_stop = sp_next_stop(prev_stop);
 338         guint i = 1;
 339         while ( (next_stop) && (next_stop->offset < offset) ) {
 340             prev_stop = next_stop;
 341             next_stop = sp_next_stop(next_stop);
 342             i++;
 343         }
 344         if (!next_stop) {
 345             // logical error: the endstop should have offset 1 and should always be more than this offset here
 346             return NULL;
 347         }
 348
 349
 350         SPStop *newstop = sp_vector_add_stop (vector, prev_stop, next_stop, offset);
 351         sp_gradient_ensure_vector (gradient);
 352         updateDraggers();
 353
 354         return newstop;
 355     }
 356
 357     return NULL;
 358 }
 359
 360
 361 bool
 362 GrDrag::dropColor(SPItem */*item*/, gchar *c, NR::Point p)
 363 {
 364     // first, see if we can drop onto one of the existing draggers
 365     for (GList *i = draggers; i != NULL; i = i->next) { // for all draggables of dragger
 366         GrDragger *d = (GrDragger *) i->data;
 367
 368         if (NR::L2(p - d->point)*desktop->current_zoom() < 5) {
 369            SPCSSAttr *stop = sp_repr_css_attr_new ();
 370            sp_repr_css_set_property (stop, "stop-color", c);
 371            sp_repr_css_set_property (stop, "stop-opacity", "1");
 372            for (GSList *j = d->draggables; j != NULL; j = j->next) { // for all draggables of dragger
 373                GrDraggable *draggable = (GrDraggable *) j->data;
 374                local_change = true;
 375                sp_item_gradient_stop_set_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke, stop);
 376            }
 377            sp_repr_css_attr_unref(stop);
 378            return true;
 379         }
 380     }
 381
 382     // now see if we're over line and create a new stop
 383     bool over_line = false;
 384     SPCtrlLine *line = NULL;
 385     if (lines) {
 386         for (GSList *l = lines; (l != NULL) && (!over_line); l = l->next) {
 387             line = (SPCtrlLine*) l->data;
 388             NR::Point nearest = snap_vector_midpoint (p, line->s, line->e, 0);
 389             double dist_screen = NR::L2 (p - nearest) * desktop->current_zoom();
 390             if (line->item && dist_screen < 5) {
 391                 SPStop *stop = addStopNearPoint (line->item, p, 5/desktop->current_zoom());
 392                 if (stop) {
 393                     SPCSSAttr *css = sp_repr_css_attr_new ();
 394                     sp_repr_css_set_property (css, "stop-color", c);
 395                     sp_repr_css_set_property (css, "stop-opacity", "1");
 396                     sp_repr_css_change (SP_OBJECT_REPR (stop), css, "style");
 397                     return true;
 398                 }
 399             }
 400         }
 401     }
 402
 403     return false;
 404 }
 405
 406
 407 GrDrag::GrDrag(SPDesktop *desktop) {
 408
 409     this->desktop = desktop;
 410
 411     this->selection = sp_desktop_selection(desktop);
 412
 413     this->draggers = NULL;
 414     this->lines = NULL;
 415     this->selected = NULL;
 416
 417     this->hor_levels.clear();
 418     this->vert_levels.clear();
 419
 420     this->local_change = false;
 421
 422     this->sel_changed_connection = this->selection->connectChanged(
 423         sigc::bind (
 424             sigc::ptr_fun(&gr_drag_sel_changed),
 425             (gpointer)this )
 426
 427         );
 428     this->sel_modified_connection = this->selection->connectModified(
 429         sigc::bind(
 430             sigc::ptr_fun(&gr_drag_sel_modified),
 431             (gpointer)this )
 432         );
 433
 434     this->style_set_connection = this->desktop->connectSetStyle(
 435         sigc::bind(
 436             sigc::ptr_fun(&gr_drag_style_set),
 437             (gpointer)this )
 438         );
 439
 440     this->style_query_connection = this->desktop->connectQueryStyle(
 441         sigc::bind(
 442             sigc::ptr_fun(&gr_drag_style_query),
 443             (gpointer)this )
 444         );
 445
 446     this->updateDraggers ();
 447     this->updateLines ();
 448     this->updateLevels ();
 449
 450     if (desktop->gr_item) {
 451         this->setSelected (getDraggerFor (desktop->gr_item, desktop->gr_point_type, desktop->gr_point_i, desktop->gr_fill_or_stroke));
 452     }
 453 }
 454
 455 GrDrag::~GrDrag()
 456 {
 457     this->sel_changed_connection.disconnect();
 458     this->sel_modified_connection.disconnect();
 459     this->style_set_connection.disconnect();
 460     this->style_query_connection.disconnect();
 461
 462     if (this->selected) {
 463         GrDraggable *draggable = (GrDraggable *)   ((GrDragger*)this->selected->data)->draggables->data;
 464         desktop->gr_item = draggable->item;
 465         desktop->gr_point_type = draggable->point_type;
 466         desktop->gr_point_i = draggable->point_i;
 467         desktop->gr_fill_or_stroke = draggable->fill_or_stroke;
 468     } else {
 469         desktop->gr_item = NULL;
 470         desktop->gr_point_type = 0;
 471         desktop->gr_point_i = 0;
 472         desktop->gr_fill_or_stroke = true;
 473     }
 474
 475     deselect_all();
 476     for (GList *l = this->draggers; l != NULL; l = l->next) {
 477         delete ((GrDragger *) l->data);
 478     }
 479     g_list_free (this->draggers);
 480     this->draggers = NULL;
 481     this->selected = NULL;
 482
 483     for (GSList *l = this->lines; l != NULL; l = l->next) {
 484         gtk_object_destroy( GTK_OBJECT (l->data));
 485     }
 486     g_slist_free (this->lines);
 487     this->lines = NULL;
 488 }
 489
 490 GrDraggable::GrDraggable (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke)
 491 {
 492     this->item = item;
 493     this->point_type = point_type;
 494     this->point_i = point_i;
 495     this->fill_or_stroke = fill_or_stroke;
 496
 497     g_object_ref (G_OBJECT (this->item));
 498 }
 499
 500 GrDraggable::~GrDraggable ()
 501 {
 502     g_object_unref (G_OBJECT (this->item));
 503 }
 504
 505
 506 SPObject *
 507 GrDraggable::getServer ()
 508 {
 509     if (!item)
 510         return NULL;
 511
 512     SPObject *server = NULL;
 513     if (fill_or_stroke)
 514         server = SP_OBJECT_STYLE_FILL_SERVER (item);
 515     else
 516         server = SP_OBJECT_STYLE_STROKE_SERVER (item);
 517
 518     return server;
 519 }
 520
 521 static void
 522 gr_knot_moved_handler(SPKnot *knot, NR::Point const *ppointer, guint state, gpointer data)
 523 {
 524     GrDragger *dragger = (GrDragger *) data;
 525     GrDrag *drag = dragger->parent;
 526
 527     NR::Point p = *ppointer;
 528
 529     // FIXME: take from prefs
 530     double snap_dist = SNAP_DIST / dragger->parent->desktop->current_zoom();
 531
 532     dragger->parent->desktop->snapindicator->remove_snappoint();
 533
 534     if (state & GDK_SHIFT_MASK) {
 535         // with Shift; unsnap if we carry more than one draggable
 536         if (dragger->draggables && dragger->draggables->next) {
 537             // create a new dragger
 538             GrDragger *dr_new = new GrDragger (dragger->parent, dragger->point, NULL);
 539             dragger->parent->draggers = g_list_prepend (dragger->parent->draggers, dr_new);
 540             // relink to it all but the first draggable in the list
 541             for (GSList const* i = dragger->draggables->next; i != NULL; i = i->next) {
 542                 GrDraggable *draggable = (GrDraggable *) i->data;
 543                 dr_new->addDraggable (draggable);
 544             }
 545             dr_new->updateKnotShape();
 546             g_slist_free (dragger->draggables->next);
 547             dragger->draggables->next = NULL;
 548             dragger->updateKnotShape();
 549             dragger->updateTip();
 550         }
 551     } else if (!(state & GDK_CONTROL_MASK)) {
 552         // without Shift or Ctrl; see if we need to snap to another dragger
 553         for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 554             GrDragger *d_new = (GrDragger *) di->data;
 555             if (dragger->mayMerge(d_new) && NR::L2 (d_new->point - p) < snap_dist) {
 556
 557                 // Merge draggers:
 558                 for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 559                     GrDraggable *draggable = (GrDraggable *) i->data;
 560                     // copy draggable to d_new:
 561                     GrDraggable *da_new = new GrDraggable (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 562                     d_new->addDraggable (da_new);
 563                 }
 564
 565                 // unlink and delete this dragger
 566                 dragger->parent->draggers = g_list_remove (dragger->parent->draggers, dragger);
 567                 delete dragger;
 568
 569                 // update the new merged dragger
 570                 d_new->fireDraggables(true, false, true);
 571                 d_new->parent->updateLines();
 572                 d_new->parent->setSelected (d_new);
 573                 d_new->updateKnotShape ();
 574                 d_new->updateTip ();
 575                 d_new->updateDependencies(true);
 576                 sp_document_done (sp_desktop_document (d_new->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 577                                   _("Merge gradient handles"));
 578                 return;
 579             }
 580         }
 581     }
 582
 583     if (!((state & GDK_SHIFT_MASK) || ((state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK)))) {
 584         // Try snapping to the grid or guides
 585         SnapManager const &m = dragger->parent->desktop->namedview->snap_manager;
 586         Inkscape::SnappedPoint s = m.freeSnap(Inkscape::Snapper::SNAPPOINT_NODE, p, NULL);
 587         if (s.getDistance() < 1e6) {
 588             p = s.getPoint();
 589             sp_knot_moveto (knot, &p);
 590             dragger->parent->desktop->snapindicator->set_new_snappoint(p.to_2geom());
 591         } else {
 592             bool was_snapped = false;
 593             Geom::Point snapped_to;
 594             // No snapping so far, let's see if we need to snap to any of the levels
 595             for (guint i = 0; i < dragger->parent->hor_levels.size(); i++) {
 596                 if (fabs(p[NR::Y] - dragger->parent->hor_levels[i]) < snap_dist) {
 597                     p[NR::Y] = dragger->parent->hor_levels[i];
 598                     snapped_to = p.to_2geom();
 599                     was_snapped = true;
 600                     sp_knot_moveto (knot, &p);
 601                 }
 602             }
 603             for (guint i = 0; i < dragger->parent->vert_levels.size(); i++) {
 604                 if (fabs(p[NR::X] - dragger->parent->vert_levels[i]) < snap_dist) {
 605                     p[NR::X] = dragger->parent->vert_levels[i];
 606                     snapped_to = p.to_2geom();
 607                     was_snapped = true;
 608                     sp_knot_moveto (knot, &p);
 609                 }
 610             }
 611             if (was_snapped) {
 612                 dragger->parent->desktop->snapindicator->set_new_snappoint(snapped_to);
 613             }
 614         }
 615     }
 616
 617     if (state & GDK_CONTROL_MASK) {
 618         unsigned snaps = abs(prefs_get_int_attribute("options.rotationsnapsperpi", "value", 12));
 619         /* 0 means no snapping. */
 620
 621         // This list will store snap vectors from all draggables of dragger
 622         GSList *snap_vectors = NULL;
 623
 624         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) {
 625             GrDraggable *draggable = (GrDraggable *) i->data;
 626
 627             NR::Point *dr_snap = NULL;
 628
 629             if (draggable->point_type == POINT_LG_BEGIN || draggable->point_type == POINT_LG_END) {
 630                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 631                     GrDragger *d_new = (GrDragger *) di->data;
 632                     if (d_new == dragger)
 633                         continue;
 634                     if (d_new->isA (draggable->item,
 635                                     draggable->point_type == POINT_LG_BEGIN? POINT_LG_END : POINT_LG_BEGIN,
 636                                     draggable->fill_or_stroke)) {
 637                         // found the other end of the linear gradient;
 638                         if (state & GDK_SHIFT_MASK) {
 639                             // moving linear around center
 640                             NR::Point center = NR::Point (0.5*(d_new->point + dragger->point));
 641                             dr_snap = &center;
 642                         } else {
 643                             // moving linear around the other end
 644                             dr_snap = &d_new->point;
 645                         }
 646                     }
 647                 }
 648             } else if (draggable->point_type == POINT_RG_R1 || draggable->point_type == POINT_RG_R2 || draggable->point_type == POINT_RG_FOCUS) {
 649                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 650                     GrDragger *d_new = (GrDragger *) di->data;
 651                     if (d_new == dragger)
 652                         continue;
 653                     if (d_new->isA (draggable->item,
 654                                     POINT_RG_CENTER,
 655                                     draggable->fill_or_stroke)) {
 656                         // found the center of the radial gradient;
 657                         dr_snap = &(d_new->point);
 658                     }
 659                 }
 660             } else if (draggable->point_type == POINT_RG_CENTER) {
 661                 // radial center snaps to hor/vert relative to its original position
 662                 dr_snap = &(dragger->point_original);
 663             }
 664
 665             NR::Point *snap_vector = NULL;
 666             if (dr_snap) {
 667                 if (state & GDK_MOD1_MASK) {
 668                     // with Alt, snap to the original angle and its perpendiculars
 669                     snap_vector = get_snap_vector (p, *dr_snap, M_PI/2, NR::atan2 (dragger->point_original - *dr_snap));
 670                 } else {
 671                     // with Ctrl, snap to M_PI/snaps
 672                     snap_vector = get_snap_vector (p, *dr_snap, M_PI/snaps, 0);
 673                 }
 674             }
 675             if (snap_vector) {
 676                 snap_vectors = g_slist_prepend (snap_vectors, snap_vector);
 677             }
 678         }
 679
 680         // Move by the smallest of snap vectors:
 681         NR::Point move(9999, 9999);
 682         for (GSList const *i = snap_vectors; i != NULL; i = i->next) {
 683             NR::Point *snap_vector = (NR::Point *) i->data;
 684             if (NR::L2(*snap_vector) < NR::L2(move))
 685                 move = *snap_vector;
 686         }
 687         if (move[NR::X] < 9999) {
 688             p += move;
 689             sp_knot_moveto (knot, &p);
 690         }
 691
 692         g_slist_free(snap_vectors);
 693     }
 694
 695     drag->keep_selection = (bool) g_list_find(drag->selected, dragger);
 696     bool scale_radial = (state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK);
 697
 698     if (drag->keep_selection) {
 699         NR::Point diff = p - dragger->point;
 700         drag->selected_move_nowrite (diff[NR::X], diff[NR::Y], scale_radial);
 701     } else {
 702         dragger->point = p;
 703         dragger->fireDraggables (false, scale_radial);
 704         dragger->updateDependencies(false);
 705     }
 706
 707 }
 708
 709
 710 static void
 711 gr_midpoint_limits(GrDragger *dragger, SPObject *server, NR::Point *begin, NR::Point *end, NR::Point *low_lim, NR::Point *high_lim, GSList **moving)
 712 {
 713
 714     GrDrag *drag = dragger->parent;
 715     // a midpoint dragger can (logically) only contain one GrDraggable
 716     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 717
 718     // get begin and end points between which dragging is allowed:
 719     // the draglimits are between knot(lowest_i - 1) and knot(highest_i + 1)
 720     *moving = g_slist_append(*moving, dragger);
 721
 722     guint lowest_i = draggable->point_i;
 723     guint highest_i = draggable->point_i;
 724     GrDragger *lowest_dragger = dragger;
 725     GrDragger *highest_dragger = dragger;
 726     if (dragger->isSelected()) {
 727         GrDragger* d_add;
 728         while ( true )
 729         {
 730             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 731             if ( d_add && g_list_find(drag->selected, d_add) ) {
 732                 lowest_i = lowest_i - 1;
 733                 *moving = g_slist_prepend(*moving, d_add);
 734                 lowest_dragger = d_add;
 735             } else {
 736                 break;
 737             }
 738         }
 739
 740         while ( true )
 741         {
 742             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 743             if ( d_add && g_list_find(drag->selected, d_add) ) {
 744                 highest_i = highest_i + 1;
 745                 *moving = g_slist_append(*moving, d_add);
 746                 highest_dragger = d_add;
 747             } else {
 748                 break;
 749             }
 750         }
 751     }
 752
 753     if ( SP_IS_LINEARGRADIENT(server) ) {
 754         guint num = SP_LINEARGRADIENT(server)->vector.stops.size();
 755         GrDragger *d_temp;
 756         if (lowest_i == 1) {
 757             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke);
 758         } else {
 759             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, lowest_i - 1, draggable->fill_or_stroke);
 760         }
 761         if (d_temp)
 762             *begin = d_temp->point;
 763
 764         d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, highest_i + 1, draggable->fill_or_stroke);
 765         if (d_temp == NULL) {
 766             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_END, num-1, draggable->fill_or_stroke);
 767         }
 768         if (d_temp)
 769             *end = d_temp->point;
 770     } else if ( SP_IS_RADIALGRADIENT(server) ) {
 771         guint num = SP_RADIALGRADIENT(server)->vector.stops.size();
 772         GrDragger *d_temp;
 773         if (lowest_i == 1) {
 774             d_temp = drag->getDraggerFor (draggable->item, POINT_RG_CENTER, 0, draggable->fill_or_stroke);
 775         } else {
 776             d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 777         }
 778         if (d_temp)
 779             *begin = d_temp->point;
 780
 781         d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 782         if (d_temp == NULL) {
 783             d_temp = drag->getDraggerFor (draggable->item, (draggable->point_type==POINT_RG_MID1) ? POINT_RG_R1 : POINT_RG_R2, num-1, draggable->fill_or_stroke);
 784         }
 785         if (d_temp)
 786             *end = d_temp->point;
 787     }
 788
 789     *low_lim  = dragger->point - (lowest_dragger->point - *begin);
 790     *high_lim = dragger->point - (highest_dragger->point - *end);
 791 }
 792
 793
 794
 795 /**
 796 Called when a midpoint knot is dragged.
 797 */
 798 static void
 799 gr_knot_moved_midpoint_handler(SPKnot */*knot*/, NR::Point const *ppointer, guint state, gpointer data)
 800 {
 801     GrDragger *dragger = (GrDragger *) data;
 802     GrDrag *drag = dragger->parent;
 803     // a midpoint dragger can (logically) only contain one GrDraggable
 804     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 805
 806     // FIXME: take from prefs
 807     double snap_fraction = 0.1;
 808
 809     NR::Point p = *ppointer;
 810     NR::Point begin(0,0), end(0,0);
 811     NR::Point low_lim(0,0), high_lim(0,0);
 812
 813     SPObject *server = draggable->getServer();
 814
 815     GSList *moving = NULL;
 816     gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
 817
 818     if (state & GDK_CONTROL_MASK) {
 819         p = snap_vector_midpoint (p, low_lim, high_lim, snap_fraction);
 820     } else {
 821         p = snap_vector_midpoint (p, low_lim, high_lim, 0);
 822     }
 823     NR::Point displacement = p - dragger->point;
 824
 825     for (GSList const* i = moving; i != NULL; i = i->next) {
 826         GrDragger *drg = (GrDragger*) i->data;
 827         SPKnot *drgknot = drg->knot;
 828         NR::Point this_move = displacement;
 829         if (state & GDK_MOD1_MASK) {
 830             // FIXME: unify all these profiles (here, in nodepath, in tweak) in one place
 831             double alpha = 1.0;
 832             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
 833                 double x = NR::L2(drg->point - dragger->point)/NR::L2(end - dragger->point);
 834                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 835             } else { // drg is on the begin side from dragger
 836                 double x = NR::L2(drg->point - dragger->point)/NR::L2(begin - dragger->point);
 837                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 838             }
 839         }
 840         drg->point += this_move;
 841         sp_knot_moveto (drgknot, & drg->point);
 842         drg->fireDraggables (false);
 843         drg->updateDependencies(false);
 844     }
 845
 846     g_slist_free(moving);
 847
 848     drag->keep_selection = dragger->isSelected();
 849 }
 850
 851
 852
 853 static void
 854 gr_knot_grabbed_handler (SPKnot */*knot*/, unsigned int /*state*/, gpointer data)
 855 {
 856     GrDragger *dragger = (GrDragger *) data;
 857
 858     sp_canvas_force_full_redraw_after_interruptions(dragger->parent->desktop->canvas, 5);
 859 }
 860
 861 /**
 862 Called when the mouse releases a dragger knot; changes gradient writing to repr, updates other draggers if needed
 863 */
 864 static void
 865 gr_knot_ungrabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 866 {
 867     GrDragger *dragger = (GrDragger *) data;
 868
 869     sp_canvas_end_forced_full_redraws(dragger->parent->desktop->canvas);
 870
 871     dragger->point_original = dragger->point = knot->pos;
 872
 873     if ((state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK)) {
 874         dragger->fireDraggables (true, true);
 875     } else {
 876         dragger->fireDraggables (true);
 877     }
 878
 879     for (GList *i = dragger->parent->selected; i != NULL; i = i->next) {
 880         GrDragger *d = (GrDragger *) i->data;
 881         if (d == dragger)
 882             continue;
 883         d->fireDraggables (true);
 884     }
 885
 886     // make this dragger selected
 887     if (!dragger->parent->keep_selection) {
 888         dragger->parent->setSelected (dragger);
 889     }
 890     dragger->parent->keep_selection = false;
 891
 892     dragger->updateDependencies(true);
 893
 894     // we did an undoable action
 895     sp_document_done (sp_desktop_document (dragger->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 896                       _("Move gradient handle"));
 897 }
 898
 899 /**
 900 Called when a dragger knot is clicked; selects the dragger or deletes it depending on the
 901 state of the keyboard keys
 902 */
 903 static void
 904 gr_knot_clicked_handler(SPKnot */*knot*/, guint state, gpointer data)
 905 {
 906     GrDragger *dragger = (GrDragger *) data;
 907     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 908     if (!draggable) return;
 909
 910     if ( (state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK ) ) {
 911     // delete this knot from vector
 912         SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
 913         gradient = sp_gradient_get_vector (gradient, false);
 914         if (gradient->vector.stops.size() > 2) { // 2 is the minimum
 915                 SPStop *stop = NULL;
 916                 switch (draggable->point_type) {  // if we delete first or last stop, move the next/previous to the edge
 917                 case POINT_LG_BEGIN:
 918                 case POINT_RG_CENTER:
 919                     stop = sp_first_stop(gradient);
 920                         {
 921                             SPStop *next = sp_next_stop (stop);
 922                                 if (next) {
 923                                         next->offset = 0;
 924                                         sp_repr_set_css_double (SP_OBJECT_REPR (next), "offset", 0);
 925                                 }
 926                         }
 927                     break;
 928                 case POINT_LG_END:
 929                 case POINT_RG_R1:
 930                 case POINT_RG_R2:
 931                     stop = sp_last_stop(gradient);
 932                     {
 933                             SPStop *prev = sp_prev_stop (stop, gradient);
 934                             if (prev) {
 935                                     prev->offset = 1;
 936                                     sp_repr_set_css_double (SP_OBJECT_REPR (prev), "offset", 1);
 937                             }
 938                         }
 939                     break;
 940                 case POINT_LG_MID:
 941                 case POINT_RG_MID1:
 942                 case POINT_RG_MID2:
 943                     stop = sp_get_stop_i(gradient, draggable->point_i);
 944                     break;
 945                 }
 946
 947                 SP_OBJECT_REPR(gradient)->removeChild(SP_OBJECT_REPR(stop));
 948                 sp_document_done (SP_OBJECT_DOCUMENT (gradient), SP_VERB_CONTEXT_GRADIENT,
 949                                   _("Delete gradient stop"));
 950         }
 951     } else {
 952     // select the dragger
 953         dragger->point_original = dragger->point;
 954
 955         if ( state & GDK_SHIFT_MASK ) {
 956             dragger->parent->setSelected (dragger, true, false);
 957         } else {
 958             dragger->parent->setSelected (dragger);
 959         }
 960     }
 961 }
 962
 963 /**
 964 Called when a dragger knot is doubleclicked; opens gradient editor with the stop from the first draggable
 965 */
 966 static void
 967 gr_knot_doubleclicked_handler (SPKnot */*knot*/, guint /*state*/, gpointer data)
 968 {
 969     GrDragger *dragger = (GrDragger *) data;
 970
 971     dragger->point_original = dragger->point;
 972
 973     if (dragger->draggables == NULL)
 974         return;
 975
 976     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 977     sp_item_gradient_edit_stop (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 978 }
 979
 980 /**
 981 Act upon all draggables of the dragger, setting them to the dragger's point
 982 */
 983 void
 984 GrDragger::fireDraggables (bool write_repr, bool scale_radial, bool merging_focus)
 985 {
 986     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 987         GrDraggable *draggable = (GrDraggable *) i->data;
 988
 989         // set local_change flag so that selection_changed callback does not regenerate draggers
 990         this->parent->local_change = true;
 991
 992         // change gradient, optionally writing to repr; prevent focus from moving if it's snapped
 993         // to the center, unless it's the first update upon merge when we must snap it to the point
 994         if (merging_focus ||
 995             !(draggable->point_type == POINT_RG_FOCUS && this->isA(draggable->item, POINT_RG_CENTER, draggable->point_i, draggable->fill_or_stroke)))
 996         {
 997             sp_item_gradient_set_coords (draggable->item, draggable->point_type, draggable->point_i, this->point, draggable->fill_or_stroke, write_repr, scale_radial);
 998         }
 999     }
1000 }
1001
1002 /**
1003 Checks if the dragger has a draggable with this point_type
1004  */
1005 bool
1006 GrDragger::isA (gint point_type)
1007 {
1008     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1009         GrDraggable *draggable = (GrDraggable *) i->data;
1010         if (draggable->point_type == point_type) {
1011             return true;
1012         }
1013     }
1014     return false;
1015 }
1016
1017 /**
1018 Checks if the dragger has a draggable with this item, point_type + point_i (number), fill_or_stroke
1019  */
1020 bool
1021 GrDragger::isA (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1022 {
1023     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1024         GrDraggable *draggable = (GrDraggable *) i->data;
1025         if ( (draggable->point_type == point_type) && (draggable->point_i == point_i) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
1026             return true;
1027         }
1028     }
1029     return false;
1030 }
1031
1032 /**
1033 Checks if the dragger has a draggable with this item, point_type, fill_or_stroke
1034  */
1035 bool
1036 GrDragger::isA (SPItem *item, gint point_type, bool fill_or_stroke)
1037 {
1038     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1039         GrDraggable *draggable = (GrDraggable *) i->data;
1040         if ( (draggable->point_type == point_type) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
1041             return true;
1042         }
1043     }
1044     return false;
1045 }
1046
1047 bool
1048 GrDraggable::mayMerge (GrDraggable *da2)
1049 {
1050     if ((this->item == da2->item) && (this->fill_or_stroke == da2->fill_or_stroke)) {
1051         // we must not merge the points of the same gradient!
1052         if (!((this->point_type == POINT_RG_FOCUS && da2->point_type == POINT_RG_CENTER) ||
1053               (this->point_type == POINT_RG_CENTER && da2->point_type == POINT_RG_FOCUS))) {
1054             // except that we can snap center and focus together
1055             return false;
1056         }
1057     }
1058     // disable merging of midpoints.
1059     if ( (this->point_type == POINT_LG_MID) || (da2->point_type == POINT_LG_MID)
1060          || (this->point_type == POINT_RG_MID1) || (da2->point_type == POINT_RG_MID1)
1061          || (this->point_type == POINT_RG_MID2) || (da2->point_type == POINT_RG_MID2) )
1062         return false;
1063
1064     return true;
1065 }
1066
1067 bool
1068 GrDragger::mayMerge (GrDragger *other)
1069 {
1070     if (this == other)
1071         return false;
1072
1073     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
1074         GrDraggable *da1 = (GrDraggable *) i->data;
1075         for (GSList const* j = other->draggables; j != NULL; j = j->next) { // for all draggables of other
1076             GrDraggable *da2 = (GrDraggable *) j->data;
1077             if (!da1->mayMerge(da2))
1078                 return false;
1079         }
1080     }
1081     return true;
1082 }
1083
1084 bool
1085 GrDragger::mayMerge (GrDraggable *da2)
1086 {
1087     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
1088         GrDraggable *da1 = (GrDraggable *) i->data;
1089         if (!da1->mayMerge(da2))
1090             return false;
1091     }
1092     return true;
1093 }
1094
1095 /**
1096 Updates the statusbar tip of the dragger knot, based on its draggables
1097  */
1098 void
1099 GrDragger::updateTip ()
1100 {
1101         if (this->knot && this->knot->tip) {
1102                 g_free (this->knot->tip);
1103                 this->knot->tip = NULL;
1104         }
1105
1106     if (g_slist_length (this->draggables) == 1) {
1107         GrDraggable *draggable = (GrDraggable *) this->draggables->data;
1108         char *item_desc = sp_item_description(draggable->item);
1109         switch (draggable->point_type) {
1110             case POINT_LG_MID:
1111             case POINT_RG_MID1:
1112             case POINT_RG_MID2:
1113                 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"),
1114                                                    _(gr_knot_descr[draggable->point_type]),
1115                                                    draggable->point_i,
1116                                                    item_desc,
1117                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
1118                 break;
1119
1120             default:
1121                 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"),
1122                                                    _(gr_knot_descr[draggable->point_type]),
1123                                                    item_desc,
1124                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
1125                 break;
1126         }
1127         g_free(item_desc);
1128     } else if (g_slist_length (draggables) == 2 && isA (POINT_RG_CENTER) && isA (POINT_RG_FOCUS)) {
1129         this->knot->tip = g_strdup_printf (_("Radial gradient <b>center</b> and <b>focus</b>; drag with <b>Shift</b> to separate focus"));
1130     } else {
1131         int length = g_slist_length (this->draggables);
1132         this->knot->tip = g_strdup_printf (ngettext("Gradient point shared by <b>%d</b> gradient; drag with <b>Shift</b> to separate",
1133                                                     "Gradient point shared by <b>%d</b> gradients; drag with <b>Shift</b> to separate",
1134                                                     length),
1135                                            length);
1136     }
1137 }
1138
1139 /**
1140 Adds a draggable to the dragger
1141  */
1142 void
1143 GrDragger::updateKnotShape ()
1144 {
1145     if (!draggables)
1146         return;
1147     GrDraggable *last = (GrDraggable *) g_slist_last(draggables)->data;
1148     g_object_set (G_OBJECT (this->knot->item), "shape", gr_knot_shapes[last->point_type], NULL);
1149 }
1150
1151 /**
1152 Adds a draggable to the dragger
1153  */
1154 void
1155 GrDragger::addDraggable (GrDraggable *draggable)
1156 {
1157     this->draggables = g_slist_prepend (this->draggables, draggable);
1158
1159     this->updateTip();
1160 }
1161
1162
1163 /**
1164 Moves this dragger to the point of the given draggable, acting upon all other draggables
1165  */
1166 void
1167 GrDragger::moveThisToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1168 {
1169     this->point = sp_item_gradient_get_coords (item, point_type, point_i, fill_or_stroke);
1170     this->point_original = this->point;
1171
1172     sp_knot_moveto (this->knot, &(this->point));
1173
1174     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1175         GrDraggable *da = (GrDraggable *) i->data;
1176         if ( (da->item == item) &&
1177              (point_type == -1 || da->point_type == point_type) &&
1178              (point_i == -1 || da->point_i == point_i) &&
1179              (da->fill_or_stroke == fill_or_stroke) ) {
1180             continue;
1181         }
1182         sp_item_gradient_set_coords (da->item, da->point_type, da->point_i, this->point, da->fill_or_stroke, write_repr, false);
1183     }
1184     // FIXME: here we should also call this->updateDependencies(write_repr); to propagate updating, but how to prevent loops?
1185 }
1186
1187
1188 /**
1189 Moves all midstop draggables that depend on this one
1190  */
1191 void
1192 GrDragger::updateMidstopDependencies (GrDraggable *draggable, bool write_repr) {
1193     SPObject *server = draggable->getServer();
1194     if (!server)
1195         return;
1196     guint num = SP_GRADIENT(server)->vector.stops.size();
1197     if (num <= 2) return;
1198
1199     if ( SP_IS_LINEARGRADIENT(server) ) {
1200         for ( guint i = 1; i < num - 1; i++ ) {
1201             this->moveOtherToDraggable (draggable->item, POINT_LG_MID, i, draggable->fill_or_stroke, write_repr);
1202         }
1203     } else  if ( SP_IS_RADIALGRADIENT(server) ) {
1204         for ( guint i = 1; i < num - 1; i++ ) {
1205             this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, i, draggable->fill_or_stroke, write_repr);
1206             this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, i, draggable->fill_or_stroke, write_repr);
1207         }
1208     }
1209 }
1210
1211
1212 /**
1213 Moves all draggables that depend on this one
1214  */
1215 void
1216 GrDragger::updateDependencies (bool write_repr)
1217 {
1218     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1219         GrDraggable *draggable = (GrDraggable *) i->data;
1220         switch (draggable->point_type) {
1221             case POINT_LG_BEGIN:
1222                 {
1223                     // the end point is dependent only when dragging with ctrl+shift
1224                     this->moveOtherToDraggable (draggable->item, POINT_LG_END, -1, draggable->fill_or_stroke, write_repr);
1225
1226                     this->updateMidstopDependencies (draggable, write_repr);
1227                 }
1228                 break;
1229             case POINT_LG_END:
1230                 {
1231                     // the begin point is dependent only when dragging with ctrl+shift
1232                     this->moveOtherToDraggable (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke, write_repr);
1233
1234                     this->updateMidstopDependencies (draggable, write_repr);
1235                 }
1236                 break;
1237             case POINT_LG_MID:
1238                 // no other nodes depend on mid points.
1239                 break;
1240             case POINT_RG_R2:
1241                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1242                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1243                 this->updateMidstopDependencies (draggable, write_repr);
1244                 break;
1245             case POINT_RG_R1:
1246                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1247                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1248                 this->updateMidstopDependencies (draggable, write_repr);
1249                 break;
1250             case POINT_RG_CENTER:
1251                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1252                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1253                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1254                 this->updateMidstopDependencies (draggable, write_repr);
1255                 break;
1256             case POINT_RG_FOCUS:
1257                 // nothing can depend on that
1258                 break;
1259             case POINT_RG_MID1:
1260                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, draggable->point_i, draggable->fill_or_stroke, write_repr);
1261                 break;
1262             case POINT_RG_MID2:
1263                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, draggable->point_i, draggable->fill_or_stroke, write_repr);
1264                 break;
1265             default:
1266                 break;
1267         }
1268     }
1269 }
1270
1271
1272
1273 GrDragger::GrDragger (GrDrag *parent, NR::Point p, GrDraggable *draggable)
1274 {
1275     this->draggables = NULL;
1276
1277     this->parent = parent;
1278
1279     this->point = p;
1280     this->point_original = p;
1281
1282     // create the knot
1283     this->knot = sp_knot_new (parent->desktop, NULL);
1284     this->knot->setMode(SP_KNOT_MODE_XOR);
1285     this->knot->setFill(GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_MOUSEOVER, GR_KNOT_COLOR_MOUSEOVER);
1286     this->knot->setStroke(0x000000ff, 0x000000ff, 0x000000ff);
1287     sp_knot_update_ctrl(this->knot);
1288
1289     // move knot to the given point
1290     sp_knot_set_position (this->knot, &p, SP_KNOT_STATE_NORMAL);
1291     sp_knot_show (this->knot);
1292
1293     // connect knot's signals
1294     if ( (draggable)  // it can be NULL if a node in unsnapped (eg. focus point unsnapped from center)
1295                        // luckily, midstops never snap to other nodes so are never unsnapped...
1296          && ( (draggable->point_type == POINT_LG_MID)
1297               || (draggable->point_type == POINT_RG_MID1)
1298               || (draggable->point_type == POINT_RG_MID2) ) )
1299     {
1300         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_midpoint_handler), this);
1301     } else {
1302         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_handler), this);
1303     }
1304     g_signal_connect (G_OBJECT (this->knot), "clicked", G_CALLBACK (gr_knot_clicked_handler), this);
1305     g_signal_connect (G_OBJECT (this->knot), "doubleclicked", G_CALLBACK (gr_knot_doubleclicked_handler), this);
1306     g_signal_connect (G_OBJECT (this->knot), "grabbed", G_CALLBACK (gr_knot_grabbed_handler), this);
1307     g_signal_connect (G_OBJECT (this->knot), "ungrabbed", G_CALLBACK (gr_knot_ungrabbed_handler), this);
1308
1309     // add the initial draggable
1310     if (draggable)
1311         this->addDraggable (draggable);
1312     updateKnotShape();
1313 }
1314
1315 GrDragger::~GrDragger ()
1316 {
1317     // unselect if it was selected
1318     this->parent->setDeselected(this);
1319
1320     // disconnect signals
1321     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_moved_handler), this);
1322     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_clicked_handler), this);
1323     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_doubleclicked_handler), this);
1324     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_grabbed_handler), this);
1325     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_ungrabbed_handler), this);
1326
1327     /* unref should call destroy */
1328     g_object_unref (G_OBJECT (this->knot));
1329
1330     // delete all draggables
1331     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1332         delete ((GrDraggable *) i->data);
1333     }
1334     g_slist_free (this->draggables);
1335     this->draggables = NULL;
1336 }
1337
1338 /**
1339 Select the dragger which has the given draggable.
1340 */
1341 GrDragger *
1342 GrDrag::getDraggerFor (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1343 {
1344     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1345         GrDragger *dragger = (GrDragger *) i->data;
1346         for (GSList const* j = dragger->draggables; j != NULL; j = j->next) {
1347             GrDraggable *da2 = (GrDraggable *) j->data;
1348             if ( (da2->item == item) &&
1349                  (point_type == -1 || da2->point_type == point_type) && // -1 means this does not matter
1350                  (point_i == -1 || da2->point_i == point_i) && // -1 means this does not matter
1351                  (da2->fill_or_stroke == fill_or_stroke)) {
1352                 return (dragger);
1353             }
1354         }
1355     }
1356     return NULL;
1357 }
1358
1359
1360 void
1361 GrDragger::moveOtherToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1362 {
1363     GrDragger *d = this->parent->getDraggerFor (item, point_type, point_i, fill_or_stroke);
1364     if (d && d !=  this) {
1365         d->moveThisToDraggable (item, point_type, point_i, fill_or_stroke, write_repr);
1366     }
1367 }
1368
1369
1370 /**
1371   Draw this dragger as selected
1372 */
1373 void
1374 GrDragger::select()
1375 {
1376     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_SELECTED;
1377     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_SELECTED, NULL);
1378 }
1379
1380 /**
1381   Draw this dragger as normal (deselected)
1382 */
1383 void
1384 GrDragger::deselect()
1385 {
1386     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_NORMAL;
1387     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_NORMAL, NULL);
1388 }
1389
1390 bool
1391 GrDragger::isSelected()
1392 {
1393     return g_list_find (parent->selected, this);
1394 }
1395
1396 /**
1397 \brief Deselect all stops/draggers (private)
1398 */
1399 void
1400 GrDrag::deselect_all()
1401 {
1402     while (selected) {
1403         ( (GrDragger*) selected->data)->deselect();
1404         selected = g_list_remove(selected, selected->data);
1405     }
1406 }
1407
1408 /**
1409 \brief Deselect all stops/draggers (public; emits signal)
1410 */
1411 void
1412 GrDrag::deselectAll()
1413 {
1414     deselect_all();
1415     this->desktop->emitToolSubselectionChanged(NULL);
1416 }
1417
1418 /**
1419 \brief Select all stops/draggers
1420 */
1421 void
1422 GrDrag::selectAll()
1423 {
1424     for (GList *l = this->draggers; l != NULL; l = l->next) {
1425         GrDragger *d = ((GrDragger *) l->data);
1426         setSelected (d, true, true);
1427     }
1428 }
1429
1430 /**
1431 \brief Select all stops/draggers that match the coords
1432 */
1433 void
1434 GrDrag::selectByCoords(std::vector<NR::Point> coords)
1435 {
1436     for (GList *l = this->draggers; l != NULL; l = l->next) {
1437         GrDragger *d = ((GrDragger *) l->data);
1438         for (guint k = 0; k < coords.size(); k++) {
1439             if (NR::L2 (d->point - coords[k]) < 1e-4) {
1440                 setSelected (d, true, true);
1441             }
1442         }
1443     }
1444 }
1445
1446
1447 /**
1448 \brief Select all stops/draggers that fall within the rect
1449 */
1450 void
1451 GrDrag::selectRect(NR::Rect const &r)
1452 {
1453     for (GList *l = this->draggers; l != NULL; l = l->next) {
1454         GrDragger *d = ((GrDragger *) l->data);
1455         if (r.contains(d->point)) {
1456            setSelected (d, true, true);
1457         }
1458     }
1459 }
1460
1461 /**
1462 \brief Select a dragger
1463 \param dragger       The dragger to select
1464 \param add_to_selection   If true, add to selection, otherwise deselect others
1465 \param override      If true, always select this node, otherwise toggle selected status
1466 */
1467 void
1468 GrDrag::setSelected (GrDragger *dragger, bool add_to_selection, bool override)
1469 {
1470     GrDragger *seldragger = NULL;
1471
1472     if (add_to_selection) {
1473         if (!dragger) return;
1474         if (override) {
1475             if (!g_list_find(selected, dragger)) {
1476                 selected = g_list_prepend(selected, dragger);
1477             }
1478             dragger->select();
1479             seldragger = dragger;
1480         } else { // toggle
1481             if (g_list_find(selected, dragger)) {
1482                 selected = g_list_remove(selected, dragger);
1483                 dragger->deselect();
1484                 if (selected) {
1485                     seldragger = (GrDragger*) selected->data; // select the dragger that is first in the list
1486                 }
1487             } else {
1488                 selected = g_list_prepend(selected, dragger);
1489                 dragger->select();
1490                 seldragger = dragger;
1491             }
1492         }
1493     } else {
1494         deselect_all();
1495         if (dragger) {
1496             selected = g_list_prepend(selected, dragger);
1497             dragger->select();
1498             seldragger = dragger;
1499         }
1500     }
1501     if (seldragger) {
1502         this->desktop->emitToolSubselectionChanged((gpointer) seldragger);
1503     }
1504 }
1505
1506 /**
1507 \brief Deselect a dragger
1508 \param dragger       The dragger to deselect
1509 */
1510 void
1511 GrDrag::setDeselected (GrDragger *dragger)
1512 {
1513     if (g_list_find(selected, dragger)) {
1514         selected = g_list_remove(selected, dragger);
1515         dragger->deselect();
1516     }
1517     this->desktop->emitToolSubselectionChanged((gpointer) (selected ? selected->data : NULL ));
1518 }
1519
1520
1521
1522 /**
1523 Create a line from p1 to p2 and add it to the lines list
1524  */
1525 void
1526 GrDrag::addLine (SPItem *item, NR::Point p1, NR::Point p2, guint32 rgba)
1527 {
1528     SPCanvasItem *line = sp_canvas_item_new(sp_desktop_controls(this->desktop),
1529                                                             SP_TYPE_CTRLLINE, NULL);
1530     SP_CTRLLINE(line)->item = item;
1531     sp_ctrlline_set_coords(SP_CTRLLINE(line), p1, p2);
1532     if (rgba != GR_LINE_COLOR_FILL) // fill is the default, so don't set color for it to speed up redraw
1533         sp_ctrlline_set_rgba32 (SP_CTRLLINE(line), rgba);
1534     sp_canvas_item_show (line);
1535     this->lines = g_slist_append (this->lines, line);
1536 }
1537
1538 /**
1539 If there already exists a dragger within MERGE_DIST of p, add the draggable to it; otherwise create
1540 new dragger and add it to draggers list
1541  */
1542 void
1543 GrDrag::addDragger (GrDraggable *draggable)
1544 {
1545     NR::Point p = sp_item_gradient_get_coords (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
1546
1547     for (GList *i = this->draggers; i != NULL; i = i->next) {
1548         GrDragger *dragger = (GrDragger *) i->data;
1549         if (dragger->mayMerge (draggable) && NR::L2 (dragger->point - p) < MERGE_DIST) {
1550             // distance is small, merge this draggable into dragger, no need to create new dragger
1551             dragger->addDraggable (draggable);
1552             dragger->updateKnotShape();
1553             return;
1554         }
1555     }
1556
1557     GrDragger *new_dragger = new GrDragger(this, p, draggable);
1558     // fixme: draggers should be added AFTER the last one: this way tabbing through them will be from begin to end.
1559     this->draggers = g_list_append (this->draggers, new_dragger);
1560 }
1561
1562 /**
1563 Add draggers for the radial gradient rg on item
1564 */
1565 void
1566 GrDrag::addDraggersRadial (SPRadialGradient *rg, SPItem *item, bool fill_or_stroke)
1567 {
1568     addDragger (new GrDraggable (item, POINT_RG_CENTER, 0, fill_or_stroke));
1569     guint num = rg->vector.stops.size();
1570     if (num > 2) {
1571         for ( guint i = 1; i < num - 1; i++ ) {
1572             addDragger (new GrDraggable (item, POINT_RG_MID1, i, fill_or_stroke));
1573         }
1574     }
1575     addDragger (new GrDraggable (item, POINT_RG_R1, num-1, fill_or_stroke));
1576     if (num > 2) {
1577         for ( guint i = 1; i < num - 1; i++ ) {
1578             addDragger (new GrDraggable (item, POINT_RG_MID2, i, fill_or_stroke));
1579         }
1580     }
1581     addDragger (new GrDraggable (item, POINT_RG_R2, num-1, fill_or_stroke));
1582     addDragger (new GrDraggable (item, POINT_RG_FOCUS, 0, fill_or_stroke));
1583 }
1584
1585 /**
1586 Add draggers for the linear gradient lg on item
1587 */
1588 void
1589 GrDrag::addDraggersLinear (SPLinearGradient *lg, SPItem *item, bool fill_or_stroke)
1590 {
1591     addDragger (new GrDraggable (item, POINT_LG_BEGIN, 0, fill_or_stroke));
1592     guint num = lg->vector.stops.size();
1593     if (num > 2) {
1594         for ( guint i = 1; i < num - 1; i++ ) {
1595             addDragger (new GrDraggable (item, POINT_LG_MID, i, fill_or_stroke));
1596         }
1597     }
1598     addDragger (new GrDraggable (item, POINT_LG_END, num-1, fill_or_stroke));
1599 }
1600
1601 /**
1602 Artificially grab the knot of this dragger; used by the gradient context
1603 */
1604 void
1605 GrDrag::grabKnot (GrDragger *dragger, gint x, gint y, guint32 etime)
1606 {
1607     if (dragger) {
1608         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1609     }
1610 }
1611
1612 /**
1613 Artificially grab the knot of the dragger with this draggable; used by the gradient context
1614 */
1615 void
1616 GrDrag::grabKnot (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, gint x, gint y, guint32 etime)
1617 {
1618     GrDragger *dragger = getDraggerFor (item, point_type, point_i, fill_or_stroke);
1619     if (dragger) {
1620         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1621     }
1622 }
1623
1624 /**
1625 Regenerates the draggers list from the current selection; is called when selection is changed or
1626 modified, also when a radial dragger needs to update positions of other draggers in the gradient
1627 */
1628 void
1629 GrDrag::updateDraggers ()
1630 {
1631     while (selected) {
1632         selected = g_list_remove(selected, selected->data);
1633     }
1634     // delete old draggers
1635     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1636         delete ((GrDragger *) i->data);
1637     }
1638     g_list_free (this->draggers);
1639     this->draggers = NULL;
1640
1641     g_return_if_fail (this->selection != NULL);
1642
1643     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1644
1645         SPItem *item = SP_ITEM(i->data);
1646         SPStyle *style = SP_OBJECT_STYLE (item);
1647
1648         if (style && (style->fill.isPaintserver())) {
1649             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1650             if (SP_IS_LINEARGRADIENT (server)) {
1651                 addDraggersLinear (SP_LINEARGRADIENT (server), item, true);
1652             } else if (SP_IS_RADIALGRADIENT (server)) {
1653                 addDraggersRadial (SP_RADIALGRADIENT (server), item, true);
1654             }
1655         }
1656
1657         if (style && (style->stroke.isPaintserver())) {
1658             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1659             if (SP_IS_LINEARGRADIENT (server)) {
1660                 addDraggersLinear (SP_LINEARGRADIENT (server), item, false);
1661             } else if (SP_IS_RADIALGRADIENT (server)) {
1662                 addDraggersRadial (SP_RADIALGRADIENT (server), item, false);
1663             }
1664         }
1665     }
1666 }
1667
1668 /**
1669 Regenerates the lines list from the current selection; is called on each move of a dragger, so that
1670 lines are always in sync with the actual gradient
1671 */
1672 void
1673 GrDrag::updateLines ()
1674 {
1675     // delete old lines
1676     for (GSList const *i = this->lines; i != NULL; i = i->next) {
1677         gtk_object_destroy( GTK_OBJECT (i->data));
1678     }
1679     g_slist_free (this->lines);
1680     this->lines = NULL;
1681
1682     g_return_if_fail (this->selection != NULL);
1683
1684     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1685
1686         SPItem *item = SP_ITEM(i->data);
1687
1688         SPStyle *style = SP_OBJECT_STYLE (item);
1689
1690         if (style && (style->fill.isPaintserver())) {
1691             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1692             if (SP_IS_LINEARGRADIENT (server)) {
1693                 this->addLine (item, 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);
1694             } else if (SP_IS_RADIALGRADIENT (server)) {
1695                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, true);
1696                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, true), GR_LINE_COLOR_FILL);
1697                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, true), GR_LINE_COLOR_FILL);
1698             }
1699         }
1700
1701         if (style && (style->stroke.isPaintserver())) {
1702             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1703             if (SP_IS_LINEARGRADIENT (server)) {
1704                 this->addLine (item, 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);
1705             } else if (SP_IS_RADIALGRADIENT (server)) {
1706                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, false);
1707                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, false), GR_LINE_COLOR_STROKE);
1708                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, false), GR_LINE_COLOR_STROKE);
1709             }
1710         }
1711     }
1712 }
1713
1714 /**
1715 Regenerates the levels list from the current selection
1716 */
1717 void
1718 GrDrag::updateLevels ()
1719 {
1720     hor_levels.clear();
1721     vert_levels.clear();
1722
1723     g_return_if_fail (this->selection != NULL);
1724
1725     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1726         SPItem *item = SP_ITEM(i->data);
1727         NR::Maybe<NR::Rect> rect = sp_item_bbox_desktop (item);
1728         if (rect) {
1729             // Remember the edges of the bbox and the center axis
1730             hor_levels.push_back(rect->min()[NR::Y]);
1731             hor_levels.push_back(rect->max()[NR::Y]);
1732             hor_levels.push_back(0.5 * (rect->min()[NR::Y] + rect->max()[NR::Y]));
1733             vert_levels.push_back(rect->min()[NR::X]);
1734             vert_levels.push_back(rect->max()[NR::X]);
1735             vert_levels.push_back(0.5 * (rect->min()[NR::X] + rect->max()[NR::X]));
1736         }
1737     }
1738 }
1739
1740 void
1741 GrDrag::selected_reverse_vector ()
1742 {
1743     if (selected == NULL)
1744         return;
1745
1746     for (GSList const* i = ( (GrDragger*) selected->data )->draggables; i != NULL; i = i->next) {
1747         GrDraggable *draggable = (GrDraggable *) i->data;
1748
1749         sp_item_gradient_reverse_vector (draggable->item, draggable->fill_or_stroke);
1750     }
1751 }
1752
1753 void
1754 GrDrag::selected_move_nowrite (double x, double y, bool scale_radial)
1755 {
1756     selected_move (x, y, false, scale_radial);
1757 }
1758
1759 void
1760 GrDrag::selected_move (double x, double y, bool write_repr, bool scale_radial)
1761 {
1762     if (selected == NULL)
1763         return;
1764
1765     bool did = false;
1766
1767     for (GList *i = selected; i != NULL; i = i->next) {
1768         GrDragger *d = (GrDragger *) i->data;
1769
1770         if (!d->isA(POINT_LG_MID) && !d->isA(POINT_RG_MID1) && !d->isA(POINT_RG_MID2)) {
1771             // if this is an endpoint,
1772
1773             // Moving an rg center moves its focus and radii as well.
1774             // therefore, if this is a focus or radius and if selection
1775             // contains the center as well, do not move this one
1776             if (d->isA(POINT_RG_R1) || d->isA(POINT_RG_R2) ||
1777                 (d->isA(POINT_RG_FOCUS) && !d->isA(POINT_RG_CENTER))) {
1778                 bool skip_radius_with_center = false;
1779                 for (GList *di = selected; di != NULL; di = di->next) {
1780                     GrDragger *d_new = (GrDragger *) di->data;
1781                     if (d_new->isA (((GrDraggable *) d->draggables->data)->item,
1782                                     POINT_RG_CENTER,
1783                                     0,
1784                                     ((GrDraggable *) d->draggables->data)->fill_or_stroke)) {
1785                         // FIXME: here we take into account only the first draggable!
1786                         skip_radius_with_center = true;
1787                     }
1788                 }
1789                 if (skip_radius_with_center)
1790                     continue;
1791             }
1792
1793             did = true;
1794             d->point += NR::Point (x, y);
1795             d->point_original = d->point;
1796             sp_knot_moveto (d->knot, &(d->point));
1797
1798             d->fireDraggables (write_repr, scale_radial);
1799
1800             d->updateDependencies(write_repr);
1801         }
1802     }
1803
1804     if (write_repr && did) {
1805         // we did an undoable action
1806         sp_document_maybe_done (sp_desktop_document (desktop), "grmoveh", SP_VERB_CONTEXT_GRADIENT,
1807                                 _("Move gradient handle(s)"));
1808         return;
1809     }
1810
1811     if (!did) { // none of the end draggers are selected, so let's try to move the mids
1812
1813         GrDragger *dragger = (GrDragger *) selected->data;
1814         // a midpoint dragger can (logically) only contain one GrDraggable
1815         GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
1816
1817         NR::Point begin(0,0), end(0,0);
1818         NR::Point low_lim(0,0), high_lim(0,0);
1819
1820         SPObject *server = draggable->getServer();
1821         GSList *moving = NULL;
1822         gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
1823
1824         NR::Point p(x, y);
1825         p = snap_vector_midpoint (dragger->point + p, low_lim, high_lim, 0);
1826         NR::Point displacement = p - dragger->point;
1827
1828         for (GSList const* i = moving; i != NULL; i = i->next) {
1829             GrDragger *drg = (GrDragger*) i->data;
1830             SPKnot *drgknot = drg->knot;
1831             drg->point += displacement;
1832             sp_knot_moveto (drgknot, & drg->point);
1833             drg->fireDraggables (true);
1834             drg->updateDependencies(true);
1835             did = true;
1836         }
1837
1838         g_slist_free(moving);
1839
1840         if (write_repr && did) {
1841             // we did an undoable action
1842             sp_document_maybe_done (sp_desktop_document (desktop), "grmovem", SP_VERB_CONTEXT_GRADIENT,
1843                                     _("Move gradient mid stop(s)"));
1844         }
1845     }
1846 }
1847
1848 void
1849 GrDrag::selected_move_screen (double x, double y)
1850 {
1851     gdouble zoom = desktop->current_zoom();
1852     gdouble zx = x / zoom;
1853     gdouble zy = y / zoom;
1854
1855     selected_move (zx, zy);
1856 }
1857
1858 /**
1859 Select the knot next to the last selected one and deselect all other selected.
1860 */
1861 GrDragger *
1862 GrDrag::select_next ()
1863 {
1864     GrDragger *d = NULL;
1865     if (selected == NULL || g_list_find(draggers, selected->data)->next == NULL) {
1866         if (draggers)
1867             d = (GrDragger *) draggers->data;
1868     } else {
1869         d = (GrDragger *) g_list_find(draggers, selected->data)->next->data;
1870     }
1871     if (d)
1872         setSelected (d);
1873     return d;
1874 }
1875
1876 /**
1877 Select the knot previous from the last selected one and deselect all other selected.
1878 */
1879 GrDragger *
1880 GrDrag::select_prev ()
1881 {
1882     GrDragger *d = NULL;
1883     if (selected == NULL || g_list_find(draggers, selected->data)->prev == NULL) {
1884         if (draggers)
1885             d = (GrDragger *) g_list_last (draggers)->data;
1886     } else {
1887         d = (GrDragger *) g_list_find(draggers, selected->data)->prev->data;
1888     }
1889     if (d)
1890         setSelected (d);
1891     return d;
1892 }
1893
1894
1895 // FIXME: i.m.o. an ugly function that I just made to work, but... aargh! (Johan)
1896 void
1897 GrDrag::deleteSelected (bool just_one)
1898 {
1899     if (!selected) return;
1900
1901     SPDocument *document = false;
1902
1903     struct StructStopInfo {
1904         SPStop * spstop;
1905         GrDraggable * draggable;
1906         SPGradient * gradient;
1907         SPGradient * vector;
1908     };
1909
1910     GSList *midstoplist = NULL;  // list of stops that must be deleted (will be deleted first)
1911     GSList *endstoplist = NULL;  // list of stops that must be deleted
1912     while (selected) {
1913         GrDragger *dragger = (GrDragger*) selected->data;
1914         for (GSList * drgble = dragger->draggables; drgble != NULL; drgble = drgble->next) {
1915             GrDraggable *draggable = (GrDraggable*) drgble->data;
1916             SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
1917             SPGradient *vector   = sp_gradient_get_forked_vector_if_necessary (gradient, false);
1918
1919             switch (draggable->point_type) {
1920                 case POINT_LG_MID:
1921                 case POINT_RG_MID1:
1922                 case POINT_RG_MID2:
1923                     {
1924                         SPStop *stop = sp_get_stop_i(vector, draggable->point_i);
1925                         // check if already present in list. (e.g. when both RG_MID1 and RG_MID2 were selected)
1926                         bool present = false;
1927                         for (GSList const * l = midstoplist; l != NULL; l = l->next) {
1928                             if ( (SPStop*)l->data == stop ) {
1929                                 present = true;
1930                                 break; // no need to search further.
1931                             }
1932                         }
1933                         if (!present)
1934                             midstoplist = g_slist_append(midstoplist, stop);
1935                     }
1936                     break;
1937                 case POINT_LG_BEGIN:
1938                 case POINT_LG_END:
1939                 case POINT_RG_CENTER:
1940                 case POINT_RG_R1:
1941                 case POINT_RG_R2:
1942                     {
1943                         SPStop *stop = NULL;
1944                         if ( (draggable->point_type == POINT_LG_BEGIN) || (draggable->point_type == POINT_RG_CENTER) ) {
1945                             stop = sp_first_stop(vector);
1946                         } else {
1947                             stop = sp_last_stop(vector);
1948                         }
1949                         if (stop) {
1950                             StructStopInfo *stopinfo = new StructStopInfo;
1951                             stopinfo->spstop = stop;
1952                             stopinfo->draggable = draggable;
1953                             stopinfo->gradient = gradient;
1954                             stopinfo->vector = vector;
1955                             // check if already present in list. (e.g. when both R1 and R2 were selected)
1956                             bool present = false;
1957                             for (GSList const * l = endstoplist; l != NULL; l = l->next) {
1958                                 if ( ((StructStopInfo*)l->data)->spstop == stopinfo->spstop ) {
1959                                     present = true;
1960                                     break; // no need to search further.
1961                                 }
1962                             }
1963                             if (!present)
1964                                 endstoplist = g_slist_append(endstoplist, stopinfo);
1965                         }
1966                     }
1967                     break;
1968                 default:
1969                     break;
1970             }
1971         }
1972         selected = g_list_remove(selected, dragger);
1973         if ( just_one ) break; // iterate once if just_one is set.
1974     }
1975     while (midstoplist) {
1976         SPStop *stop = (SPStop*) midstoplist->data;
1977         document = SP_OBJECT_DOCUMENT (stop);
1978         Inkscape::XML::Node * parent = SP_OBJECT_REPR(stop)->parent();
1979         parent->removeChild(SP_OBJECT_REPR(stop));
1980         midstoplist = g_slist_remove(midstoplist, stop);
1981     }
1982     while (endstoplist) {
1983         StructStopInfo *stopinfo  = (StructStopInfo*) endstoplist->data;
1984         document = SP_OBJECT_DOCUMENT (stopinfo->spstop);
1985
1986         // 2 is the minimum, cannot delete more than that without deleting the whole vector
1987         // cannot use vector->vector.stops.size() because the vector might be invalidated by deletion of a midstop
1988         // manually count the children, don't know if there already exists a function for this...
1989         int len = 0;
1990         for ( SPObject *child = sp_object_first_child(stopinfo->vector) ;
1991               child != NULL ;
1992               child = SP_OBJECT_NEXT(child) )
1993         {
1994             if ( SP_IS_STOP(child) )  len ++;
1995         }
1996         if (len > 2)
1997         {
1998             switch (stopinfo->draggable->point_type) {
1999                 case POINT_LG_BEGIN:
2000                     {
2001                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2002
2003                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
2004                         NR::Point oldbegin = NR::Point (lg->x1.computed, lg->y1.computed);
2005                         NR::Point end = NR::Point (lg->x2.computed, lg->y2.computed);
2006                         SPStop *stop = sp_first_stop(stopinfo->vector);
2007                         gdouble offset = stop->offset;
2008                         NR::Point newbegin = oldbegin + offset * (end - oldbegin);
2009                         lg->x1.computed = newbegin[NR::X];
2010                         lg->y1.computed = newbegin[NR::Y];
2011
2012                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
2013                         sp_repr_set_svg_double(repr, "x1", lg->x1.computed);
2014                         sp_repr_set_svg_double(repr, "y1", lg->y1.computed);
2015                         stop->offset = 0;
2016                         sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", 0);
2017
2018                         // iterate through midstops to set new offset values such that they won't move on canvas.
2019                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2020                         stop = sp_next_stop(stop);
2021                         while ( stop != laststop ) {
2022                             stop->offset = (stop->offset - offset)/(1 - offset);
2023                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2024                             stop = sp_next_stop(stop);
2025                         }
2026                     }
2027                     break;
2028                 case POINT_LG_END:
2029                     {
2030                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2031
2032                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
2033                         NR::Point begin = NR::Point (lg->x1.computed, lg->y1.computed);
2034                         NR::Point oldend = NR::Point (lg->x2.computed, lg->y2.computed);
2035                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2036                         gdouble offset = laststop->offset;
2037                         NR::Point newend = begin + offset * (oldend - begin);
2038                         lg->x2.computed = newend[NR::X];
2039                         lg->y2.computed = newend[NR::Y];
2040
2041                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
2042                         sp_repr_set_svg_double(repr, "x2", lg->x2.computed);
2043                         sp_repr_set_svg_double(repr, "y2", lg->y2.computed);
2044                         laststop->offset = 1;
2045                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
2046
2047                         // iterate through midstops to set new offset values such that they won't move on canvas.
2048                         SPStop *stop = sp_first_stop(stopinfo->vector);
2049                         stop = sp_next_stop(stop);
2050                         while ( stop != laststop ) {
2051                             stop->offset = stop->offset / offset;
2052                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2053                             stop = sp_next_stop(stop);
2054                         }
2055                     }
2056                     break;
2057                 case POINT_RG_CENTER:
2058                     {
2059                         SPStop *newfirst = sp_next_stop (stopinfo->spstop);
2060                         if (newfirst) {
2061                             newfirst->offset = 0;
2062                             sp_repr_set_css_double (SP_OBJECT_REPR (newfirst), "offset", 0);
2063                         }
2064                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2065                     }
2066                     break;
2067                 case POINT_RG_R1:
2068                 case POINT_RG_R2:
2069                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2070
2071                         SPRadialGradient *rg = SP_RADIALGRADIENT(stopinfo->gradient);
2072                         double oldradius = rg->r.computed;
2073                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2074                         gdouble offset = laststop->offset;
2075                         double newradius = offset * oldradius;
2076                         rg->r.computed = newradius;
2077
2078                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(rg);
2079                         sp_repr_set_svg_double(repr, "r", rg->r.computed);
2080                         laststop->offset = 1;
2081                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
2082
2083                         // iterate through midstops to set new offset values such that they won't move on canvas.
2084                         SPStop *stop = sp_first_stop(stopinfo->vector);
2085                         stop = sp_next_stop(stop);
2086                         while ( stop != laststop ) {
2087                             stop->offset = stop->offset / offset;
2088                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2089                             stop = sp_next_stop(stop);
2090                         }
2091                         break;
2092             }
2093         }
2094         else
2095         { // delete the gradient from the object. set fill to unset  FIXME: set to fill of unselected node?
2096             SPCSSAttr *css = sp_repr_css_attr_new ();
2097
2098             // stopinfo->spstop is the selected stop
2099             Inkscape::XML::Node *unselectedrepr = SP_OBJECT_REPR(stopinfo->vector)->firstChild();
2100             if (unselectedrepr == SP_OBJECT_REPR(stopinfo->spstop) ) {
2101                 unselectedrepr = unselectedrepr->next();
2102             }
2103
2104             if (unselectedrepr == NULL) {
2105                 if (stopinfo->draggable->fill_or_stroke) {
2106                     sp_repr_css_unset_property (css, "fill");
2107                 } else {
2108                     sp_repr_css_unset_property (css, "stroke");
2109                 }
2110             } else {
2111                 SPCSSAttr *stopcss = sp_repr_css_attr(unselectedrepr, "style");
2112                 if (stopinfo->draggable->fill_or_stroke) {
2113                     sp_repr_css_set_property(css, "fill", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
2114                     sp_repr_css_set_property(css, "fill-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
2115                 } else {
2116                     sp_repr_css_set_property(css, "stroke", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
2117                     sp_repr_css_set_property(css, "stroke-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
2118                 }
2119                 sp_repr_css_attr_unref (stopcss);
2120             }
2121
2122             sp_repr_css_change (SP_OBJECT_REPR (stopinfo->draggable->item), css, "style");
2123             sp_repr_css_attr_unref (css);
2124         }
2125
2126         endstoplist = g_slist_remove(endstoplist, stopinfo);
2127         delete stopinfo;
2128     }
2129
2130     if (document) {
2131         sp_document_done ( document, SP_VERB_CONTEXT_GRADIENT, _("Delete gradient stop(s)") );
2132     }
2133 }
2134
2135
2136 /*
2137   Local Variables:
2138   mode:c++
2139   c-file-style:"stroustrup"
2140   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
2141   indent-tabs-mode:nil
2142   fill-column:99
2143   End:
2144 */
2145 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :