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 bool
 253 GrDrag::copy()
 254 {
 255     if (!selected)
 256         return false;
 257
 258     float cf[4];
 259     cf[0] = cf[1] = cf[2] = cf[3] = 0;
 260
 261     int count = 0;
 262
 263     for (GList *i = selected; i != NULL; i = i->next) { // for all selected draggers
 264         GrDragger *d = (GrDragger *) i->data;
 265         for (GSList const* j = d->draggables; j != NULL; j = j->next) { // for all draggables of dragger
 266             GrDraggable *draggable = (GrDraggable *) j->data;
 267
 268             guint32 c = sp_item_gradient_stop_query_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 269             cf[0] += SP_RGBA32_R_F (c);
 270             cf[1] += SP_RGBA32_G_F (c);
 271             cf[2] += SP_RGBA32_B_F (c);
 272             cf[3] += SP_RGBA32_A_F (c);
 273
 274             count ++;
 275         }
 276     }
 277
 278     if (count) {
 279         cf[0] /= count;
 280         cf[1] /= count;
 281         cf[2] /= count;
 282         cf[3] /= count;
 283     }
 284
 285     guint32 const c32 = SP_RGBA32_F_COMPOSE(cf[0], cf[1], cf[2], cf[3]);
 286     gchar c[64];
 287
 288     SPCSSAttr *css = sp_repr_css_attr_new ();
 289     g_snprintf(c, 64, "#%06x", c32 >> 8);
 290     sp_repr_css_set_property (css, "fill", c);
 291     Inkscape::CSSOStringStream os;
 292     os << cf[3];
 293     sp_repr_css_set_property (css, "opacity", os.str().c_str());
 294     sp_set_style_clipboard (css);
 295
 296     g_snprintf(c, 64, "%06x%02x", c32 >> 8, c32 & 0x000000ff);
 297     Glib::ustring text;
 298     text += c;
 299     if (!text.empty())
 300     {
 301         Glib::RefPtr<Gtk::Clipboard> refClipboard =
 302             Gtk::Clipboard::get();
 303         refClipboard->set_text(text);
 304     }
 305
 306     return true;
 307 }
 308
 309 SPStop *
 310 GrDrag::addStopNearPoint (SPItem *item, NR::Point mouse_p, double tolerance)
 311 {
 312     gfloat offset; // type of SPStop.offset = gfloat
 313     SPGradient *gradient;
 314     bool fill_or_stroke = true;
 315     bool r1_knot = false;
 316
 317     bool addknot = false;
 318     do {
 319         gradient = sp_item_gradient (item, fill_or_stroke);
 320         if (SP_IS_LINEARGRADIENT(gradient)) {
 321             NR::Point begin   = sp_item_gradient_get_coords(item, POINT_LG_BEGIN, 0, fill_or_stroke);
 322             NR::Point end     = sp_item_gradient_get_coords(item, POINT_LG_END, 0, fill_or_stroke);
 323
 324             NR::Point nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 325             double dist_screen = NR::L2 (mouse_p - nearest);
 326             if ( dist_screen < tolerance ) {
 327                 // add the knot
 328                 offset = get_offset_between_points(nearest, begin, end);
 329                 addknot = true;
 330                 break; // break out of the while loop: add only one knot
 331             }
 332         } else if (SP_IS_RADIALGRADIENT(gradient)) {
 333             NR::Point begin = sp_item_gradient_get_coords(item, POINT_RG_CENTER, 0, fill_or_stroke);
 334             NR::Point end   = sp_item_gradient_get_coords(item, POINT_RG_R1, 0, fill_or_stroke);
 335             NR::Point nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 336             double dist_screen = NR::L2 (mouse_p - nearest);
 337             if ( dist_screen < tolerance ) {
 338                 offset = get_offset_between_points(nearest, begin, end);
 339                 addknot = true;
 340                 r1_knot = true;
 341                 break; // break out of the while loop: add only one knot
 342             }
 343
 344             end    = sp_item_gradient_get_coords(item, POINT_RG_R2, 0, fill_or_stroke);
 345             nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 346             dist_screen = NR::L2 (mouse_p - nearest);
 347             if ( dist_screen < tolerance ) {
 348                 offset = get_offset_between_points(nearest, begin, end);
 349                 addknot = true;
 350                 r1_knot = false;
 351                 break; // break out of the while loop: add only one knot
 352             }
 353         }
 354         fill_or_stroke = !fill_or_stroke;
 355     } while (!fill_or_stroke && !addknot) ;
 356
 357     if (addknot) {
 358         SPGradient *vector = sp_gradient_get_forked_vector_if_necessary (gradient, false);
 359         SPStop* prev_stop = sp_first_stop(vector);
 360         SPStop* next_stop = sp_next_stop(prev_stop);
 361         guint i = 1;
 362         while ( (next_stop) && (next_stop->offset < offset) ) {
 363             prev_stop = next_stop;
 364             next_stop = sp_next_stop(next_stop);
 365             i++;
 366         }
 367         if (!next_stop) {
 368             // logical error: the endstop should have offset 1 and should always be more than this offset here
 369             return NULL;
 370         }
 371
 372
 373         SPStop *newstop = sp_vector_add_stop (vector, prev_stop, next_stop, offset);
 374         sp_gradient_ensure_vector (gradient);
 375         updateDraggers();
 376
 377         return newstop;
 378     }
 379
 380     return NULL;
 381 }
 382
 383
 384 bool
 385 GrDrag::dropColor(SPItem */*item*/, gchar *c, NR::Point p)
 386 {
 387     // first, see if we can drop onto one of the existing draggers
 388     for (GList *i = draggers; i != NULL; i = i->next) { // for all draggables of dragger
 389         GrDragger *d = (GrDragger *) i->data;
 390
 391         if (NR::L2(p - d->point)*desktop->current_zoom() < 5) {
 392            SPCSSAttr *stop = sp_repr_css_attr_new ();
 393            sp_repr_css_set_property (stop, "stop-color", c);
 394            sp_repr_css_set_property (stop, "stop-opacity", "1");
 395            for (GSList *j = d->draggables; j != NULL; j = j->next) { // for all draggables of dragger
 396                GrDraggable *draggable = (GrDraggable *) j->data;
 397                local_change = true;
 398                sp_item_gradient_stop_set_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke, stop);
 399            }
 400            sp_repr_css_attr_unref(stop);
 401            return true;
 402         }
 403     }
 404
 405     // now see if we're over line and create a new stop
 406     bool over_line = false;
 407     SPCtrlLine *line = NULL;
 408     if (lines) {
 409         for (GSList *l = lines; (l != NULL) && (!over_line); l = l->next) {
 410             line = (SPCtrlLine*) l->data;
 411             NR::Point nearest = snap_vector_midpoint (p, line->s, line->e, 0);
 412             double dist_screen = NR::L2 (p - nearest) * desktop->current_zoom();
 413             if (line->item && dist_screen < 5) {
 414                 SPStop *stop = addStopNearPoint (line->item, p, 5/desktop->current_zoom());
 415                 if (stop) {
 416                     SPCSSAttr *css = sp_repr_css_attr_new ();
 417                     sp_repr_css_set_property (css, "stop-color", c);
 418                     sp_repr_css_set_property (css, "stop-opacity", "1");
 419                     sp_repr_css_change (SP_OBJECT_REPR (stop), css, "style");
 420                     return true;
 421                 }
 422             }
 423         }
 424     }
 425
 426     return false;
 427 }
 428
 429
 430 GrDrag::GrDrag(SPDesktop *desktop) {
 431
 432     this->desktop = desktop;
 433
 434     this->selection = sp_desktop_selection(desktop);
 435
 436     this->draggers = NULL;
 437     this->lines = NULL;
 438     this->selected = NULL;
 439
 440     this->hor_levels.clear();
 441     this->vert_levels.clear();
 442
 443     this->local_change = false;
 444
 445     this->sel_changed_connection = this->selection->connectChanged(
 446         sigc::bind (
 447             sigc::ptr_fun(&gr_drag_sel_changed),
 448             (gpointer)this )
 449
 450         );
 451     this->sel_modified_connection = this->selection->connectModified(
 452         sigc::bind(
 453             sigc::ptr_fun(&gr_drag_sel_modified),
 454             (gpointer)this )
 455         );
 456
 457     this->style_set_connection = this->desktop->connectSetStyle(
 458         sigc::bind(
 459             sigc::ptr_fun(&gr_drag_style_set),
 460             (gpointer)this )
 461         );
 462
 463     this->style_query_connection = this->desktop->connectQueryStyle(
 464         sigc::bind(
 465             sigc::ptr_fun(&gr_drag_style_query),
 466             (gpointer)this )
 467         );
 468
 469     this->updateDraggers ();
 470     this->updateLines ();
 471     this->updateLevels ();
 472
 473     if (desktop->gr_item) {
 474         this->setSelected (getDraggerFor (desktop->gr_item, desktop->gr_point_type, desktop->gr_point_i, desktop->gr_fill_or_stroke));
 475     }
 476 }
 477
 478 GrDrag::~GrDrag()
 479 {
 480     this->sel_changed_connection.disconnect();
 481     this->sel_modified_connection.disconnect();
 482     this->style_set_connection.disconnect();
 483     this->style_query_connection.disconnect();
 484
 485     if (this->selected) {
 486         GrDraggable *draggable = (GrDraggable *)   ((GrDragger*)this->selected->data)->draggables->data;
 487         desktop->gr_item = draggable->item;
 488         desktop->gr_point_type = draggable->point_type;
 489         desktop->gr_point_i = draggable->point_i;
 490         desktop->gr_fill_or_stroke = draggable->fill_or_stroke;
 491     } else {
 492         desktop->gr_item = NULL;
 493         desktop->gr_point_type = 0;
 494         desktop->gr_point_i = 0;
 495         desktop->gr_fill_or_stroke = true;
 496     }
 497
 498     deselect_all();
 499     for (GList *l = this->draggers; l != NULL; l = l->next) {
 500         delete ((GrDragger *) l->data);
 501     }
 502     g_list_free (this->draggers);
 503     this->draggers = NULL;
 504     this->selected = NULL;
 505
 506     for (GSList *l = this->lines; l != NULL; l = l->next) {
 507         gtk_object_destroy( GTK_OBJECT (l->data));
 508     }
 509     g_slist_free (this->lines);
 510     this->lines = NULL;
 511 }
 512
 513 GrDraggable::GrDraggable (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke)
 514 {
 515     this->item = item;
 516     this->point_type = point_type;
 517     this->point_i = point_i;
 518     this->fill_or_stroke = fill_or_stroke;
 519
 520     g_object_ref (G_OBJECT (this->item));
 521 }
 522
 523 GrDraggable::~GrDraggable ()
 524 {
 525     g_object_unref (G_OBJECT (this->item));
 526 }
 527
 528
 529 SPObject *
 530 GrDraggable::getServer ()
 531 {
 532     if (!item)
 533         return NULL;
 534
 535     SPObject *server = NULL;
 536     if (fill_or_stroke)
 537         server = SP_OBJECT_STYLE_FILL_SERVER (item);
 538     else
 539         server = SP_OBJECT_STYLE_STROKE_SERVER (item);
 540
 541     return server;
 542 }
 543
 544 static void
 545 gr_knot_moved_handler(SPKnot *knot, NR::Point const *ppointer, guint state, gpointer data)
 546 {
 547     GrDragger *dragger = (GrDragger *) data;
 548     GrDrag *drag = dragger->parent;
 549
 550     NR::Point p = *ppointer;
 551
 552     // FIXME: take from prefs
 553     double snap_dist = SNAP_DIST / dragger->parent->desktop->current_zoom();
 554
 555     dragger->parent->desktop->snapindicator->remove_snappoint();
 556
 557     if (state & GDK_SHIFT_MASK) {
 558         // with Shift; unsnap if we carry more than one draggable
 559         if (dragger->draggables && dragger->draggables->next) {
 560             // create a new dragger
 561             GrDragger *dr_new = new GrDragger (dragger->parent, dragger->point, NULL);
 562             dragger->parent->draggers = g_list_prepend (dragger->parent->draggers, dr_new);
 563             // relink to it all but the first draggable in the list
 564             for (GSList const* i = dragger->draggables->next; i != NULL; i = i->next) {
 565                 GrDraggable *draggable = (GrDraggable *) i->data;
 566                 dr_new->addDraggable (draggable);
 567             }
 568             dr_new->updateKnotShape();
 569             g_slist_free (dragger->draggables->next);
 570             dragger->draggables->next = NULL;
 571             dragger->updateKnotShape();
 572             dragger->updateTip();
 573         }
 574     } else if (!(state & GDK_CONTROL_MASK)) {
 575         // without Shift or Ctrl; see if we need to snap to another dragger
 576         for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 577             GrDragger *d_new = (GrDragger *) di->data;
 578             if (dragger->mayMerge(d_new) && NR::L2 (d_new->point - p) < snap_dist) {
 579
 580                 // Merge draggers:
 581                 for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 582                     GrDraggable *draggable = (GrDraggable *) i->data;
 583                     // copy draggable to d_new:
 584                     GrDraggable *da_new = new GrDraggable (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 585                     d_new->addDraggable (da_new);
 586                 }
 587
 588                 // unlink and delete this dragger
 589                 dragger->parent->draggers = g_list_remove (dragger->parent->draggers, dragger);
 590                 delete dragger;
 591
 592                 // update the new merged dragger
 593                 d_new->fireDraggables(true, false, true);
 594                 d_new->parent->updateLines();
 595                 d_new->parent->setSelected (d_new);
 596                 d_new->updateKnotShape ();
 597                 d_new->updateTip ();
 598                 d_new->updateDependencies(true);
 599                 sp_document_done (sp_desktop_document (d_new->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 600                                   _("Merge gradient handles"));
 601                 return;
 602             }
 603         }
 604     }
 605
 606     if (!((state & GDK_SHIFT_MASK) || ((state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK)))) {
 607         // Try snapping to the grid or guides
 608         SnapManager const &m = dragger->parent->desktop->namedview->snap_manager;
 609         Inkscape::SnappedPoint s = m.freeSnap(Inkscape::Snapper::SNAPPOINT_NODE, p, NULL);
 610         if (s.getDistance() < 1e6) {
 611             p = s.getPoint();
 612             sp_knot_moveto (knot, &p);
 613             dragger->parent->desktop->snapindicator->set_new_snappoint(p.to_2geom());
 614         } else {
 615             bool was_snapped = false;
 616             Geom::Point snapped_to;
 617             // No snapping so far, let's see if we need to snap to any of the levels
 618             for (guint i = 0; i < dragger->parent->hor_levels.size(); i++) {
 619                 if (fabs(p[NR::Y] - dragger->parent->hor_levels[i]) < snap_dist) {
 620                     p[NR::Y] = dragger->parent->hor_levels[i];
 621                     snapped_to = p.to_2geom();
 622                     was_snapped = true;
 623                     sp_knot_moveto (knot, &p);
 624                 }
 625             }
 626             for (guint i = 0; i < dragger->parent->vert_levels.size(); i++) {
 627                 if (fabs(p[NR::X] - dragger->parent->vert_levels[i]) < snap_dist) {
 628                     p[NR::X] = dragger->parent->vert_levels[i];
 629                     snapped_to = p.to_2geom();
 630                     was_snapped = true;
 631                     sp_knot_moveto (knot, &p);
 632                 }
 633             }
 634             if (was_snapped) {
 635                 dragger->parent->desktop->snapindicator->set_new_snappoint(snapped_to);
 636             }
 637         }
 638     }
 639
 640     if (state & GDK_CONTROL_MASK) {
 641         unsigned snaps = abs(prefs_get_int_attribute("options.rotationsnapsperpi", "value", 12));
 642         /* 0 means no snapping. */
 643
 644         // This list will store snap vectors from all draggables of dragger
 645         GSList *snap_vectors = NULL;
 646
 647         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) {
 648             GrDraggable *draggable = (GrDraggable *) i->data;
 649
 650             NR::Point *dr_snap = NULL;
 651
 652             if (draggable->point_type == POINT_LG_BEGIN || draggable->point_type == POINT_LG_END) {
 653                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 654                     GrDragger *d_new = (GrDragger *) di->data;
 655                     if (d_new == dragger)
 656                         continue;
 657                     if (d_new->isA (draggable->item,
 658                                     draggable->point_type == POINT_LG_BEGIN? POINT_LG_END : POINT_LG_BEGIN,
 659                                     draggable->fill_or_stroke)) {
 660                         // found the other end of the linear gradient;
 661                         if (state & GDK_SHIFT_MASK) {
 662                             // moving linear around center
 663                             NR::Point center = NR::Point (0.5*(d_new->point + dragger->point));
 664                             dr_snap = &center;
 665                         } else {
 666                             // moving linear around the other end
 667                             dr_snap = &d_new->point;
 668                         }
 669                     }
 670                 }
 671             } else if (draggable->point_type == POINT_RG_R1 || draggable->point_type == POINT_RG_R2 || draggable->point_type == POINT_RG_FOCUS) {
 672                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 673                     GrDragger *d_new = (GrDragger *) di->data;
 674                     if (d_new == dragger)
 675                         continue;
 676                     if (d_new->isA (draggable->item,
 677                                     POINT_RG_CENTER,
 678                                     draggable->fill_or_stroke)) {
 679                         // found the center of the radial gradient;
 680                         dr_snap = &(d_new->point);
 681                     }
 682                 }
 683             } else if (draggable->point_type == POINT_RG_CENTER) {
 684                 // radial center snaps to hor/vert relative to its original position
 685                 dr_snap = &(dragger->point_original);
 686             }
 687
 688             NR::Point *snap_vector = NULL;
 689             if (dr_snap) {
 690                 if (state & GDK_MOD1_MASK) {
 691                     // with Alt, snap to the original angle and its perpendiculars
 692                     snap_vector = get_snap_vector (p, *dr_snap, M_PI/2, NR::atan2 (dragger->point_original - *dr_snap));
 693                 } else {
 694                     // with Ctrl, snap to M_PI/snaps
 695                     snap_vector = get_snap_vector (p, *dr_snap, M_PI/snaps, 0);
 696                 }
 697             }
 698             if (snap_vector) {
 699                 snap_vectors = g_slist_prepend (snap_vectors, snap_vector);
 700             }
 701         }
 702
 703         // Move by the smallest of snap vectors:
 704         NR::Point move(9999, 9999);
 705         for (GSList const *i = snap_vectors; i != NULL; i = i->next) {
 706             NR::Point *snap_vector = (NR::Point *) i->data;
 707             if (NR::L2(*snap_vector) < NR::L2(move))
 708                 move = *snap_vector;
 709         }
 710         if (move[NR::X] < 9999) {
 711             p += move;
 712             sp_knot_moveto (knot, &p);
 713         }
 714
 715         g_slist_free(snap_vectors);
 716     }
 717
 718     drag->keep_selection = (bool) g_list_find(drag->selected, dragger);
 719     bool scale_radial = (state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK);
 720
 721     if (drag->keep_selection) {
 722         NR::Point diff = p - dragger->point;
 723         drag->selected_move_nowrite (diff[NR::X], diff[NR::Y], scale_radial);
 724     } else {
 725         dragger->point = p;
 726         dragger->fireDraggables (false, scale_radial);
 727         dragger->updateDependencies(false);
 728     }
 729
 730 }
 731
 732
 733 static void
 734 gr_midpoint_limits(GrDragger *dragger, SPObject *server, NR::Point *begin, NR::Point *end, NR::Point *low_lim, NR::Point *high_lim, GSList **moving)
 735 {
 736
 737     GrDrag *drag = dragger->parent;
 738     // a midpoint dragger can (logically) only contain one GrDraggable
 739     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 740
 741     // get begin and end points between which dragging is allowed:
 742     // the draglimits are between knot(lowest_i - 1) and knot(highest_i + 1)
 743     *moving = g_slist_append(*moving, dragger);
 744
 745     guint lowest_i = draggable->point_i;
 746     guint highest_i = draggable->point_i;
 747     GrDragger *lowest_dragger = dragger;
 748     GrDragger *highest_dragger = dragger;
 749     if (dragger->isSelected()) {
 750         GrDragger* d_add;
 751         while ( true )
 752         {
 753             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 754             if ( d_add && g_list_find(drag->selected, d_add) ) {
 755                 lowest_i = lowest_i - 1;
 756                 *moving = g_slist_prepend(*moving, d_add);
 757                 lowest_dragger = d_add;
 758             } else {
 759                 break;
 760             }
 761         }
 762
 763         while ( true )
 764         {
 765             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 766             if ( d_add && g_list_find(drag->selected, d_add) ) {
 767                 highest_i = highest_i + 1;
 768                 *moving = g_slist_append(*moving, d_add);
 769                 highest_dragger = d_add;
 770             } else {
 771                 break;
 772             }
 773         }
 774     }
 775
 776     if ( SP_IS_LINEARGRADIENT(server) ) {
 777         guint num = SP_LINEARGRADIENT(server)->vector.stops.size();
 778         GrDragger *d_temp;
 779         if (lowest_i == 1) {
 780             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke);
 781         } else {
 782             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, lowest_i - 1, draggable->fill_or_stroke);
 783         }
 784         if (d_temp)
 785             *begin = d_temp->point;
 786
 787         d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, highest_i + 1, draggable->fill_or_stroke);
 788         if (d_temp == NULL) {
 789             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_END, num-1, draggable->fill_or_stroke);
 790         }
 791         if (d_temp)
 792             *end = d_temp->point;
 793     } else if ( SP_IS_RADIALGRADIENT(server) ) {
 794         guint num = SP_RADIALGRADIENT(server)->vector.stops.size();
 795         GrDragger *d_temp;
 796         if (lowest_i == 1) {
 797             d_temp = drag->getDraggerFor (draggable->item, POINT_RG_CENTER, 0, draggable->fill_or_stroke);
 798         } else {
 799             d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 800         }
 801         if (d_temp)
 802             *begin = d_temp->point;
 803
 804         d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 805         if (d_temp == NULL) {
 806             d_temp = drag->getDraggerFor (draggable->item, (draggable->point_type==POINT_RG_MID1) ? POINT_RG_R1 : POINT_RG_R2, num-1, draggable->fill_or_stroke);
 807         }
 808         if (d_temp)
 809             *end = d_temp->point;
 810     }
 811
 812     *low_lim  = dragger->point - (lowest_dragger->point - *begin);
 813     *high_lim = dragger->point - (highest_dragger->point - *end);
 814 }
 815
 816
 817
 818 /**
 819 Called when a midpoint knot is dragged.
 820 */
 821 static void
 822 gr_knot_moved_midpoint_handler(SPKnot */*knot*/, NR::Point const *ppointer, guint state, gpointer data)
 823 {
 824     GrDragger *dragger = (GrDragger *) data;
 825     GrDrag *drag = dragger->parent;
 826     // a midpoint dragger can (logically) only contain one GrDraggable
 827     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 828
 829     // FIXME: take from prefs
 830     double snap_fraction = 0.1;
 831
 832     NR::Point p = *ppointer;
 833     NR::Point begin(0,0), end(0,0);
 834     NR::Point low_lim(0,0), high_lim(0,0);
 835
 836     SPObject *server = draggable->getServer();
 837
 838     GSList *moving = NULL;
 839     gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
 840
 841     if (state & GDK_CONTROL_MASK) {
 842         p = snap_vector_midpoint (p, low_lim, high_lim, snap_fraction);
 843     } else {
 844         p = snap_vector_midpoint (p, low_lim, high_lim, 0);
 845     }
 846     NR::Point displacement = p - dragger->point;
 847
 848     for (GSList const* i = moving; i != NULL; i = i->next) {
 849         GrDragger *drg = (GrDragger*) i->data;
 850         SPKnot *drgknot = drg->knot;
 851         NR::Point this_move = displacement;
 852         if (state & GDK_MOD1_MASK) {
 853             // FIXME: unify all these profiles (here, in nodepath, in tweak) in one place
 854             double alpha = 1.0;
 855             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
 856                 double x = NR::L2(drg->point - dragger->point)/NR::L2(end - dragger->point);
 857                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 858             } else { // drg is on the begin side from dragger
 859                 double x = NR::L2(drg->point - dragger->point)/NR::L2(begin - dragger->point);
 860                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 861             }
 862         }
 863         drg->point += this_move;
 864         sp_knot_moveto (drgknot, & drg->point);
 865         drg->fireDraggables (false);
 866         drg->updateDependencies(false);
 867     }
 868
 869     g_slist_free(moving);
 870
 871     drag->keep_selection = dragger->isSelected();
 872 }
 873
 874
 875
 876 static void
 877 gr_knot_grabbed_handler (SPKnot */*knot*/, unsigned int /*state*/, gpointer data)
 878 {
 879     GrDragger *dragger = (GrDragger *) data;
 880
 881     sp_canvas_force_full_redraw_after_interruptions(dragger->parent->desktop->canvas, 5);
 882 }
 883
 884 /**
 885 Called when the mouse releases a dragger knot; changes gradient writing to repr, updates other draggers if needed
 886 */
 887 static void
 888 gr_knot_ungrabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 889 {
 890     GrDragger *dragger = (GrDragger *) data;
 891
 892     sp_canvas_end_forced_full_redraws(dragger->parent->desktop->canvas);
 893
 894     dragger->point_original = dragger->point = knot->pos;
 895
 896     if ((state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK)) {
 897         dragger->fireDraggables (true, true);
 898     } else {
 899         dragger->fireDraggables (true);
 900     }
 901
 902     for (GList *i = dragger->parent->selected; i != NULL; i = i->next) {
 903         GrDragger *d = (GrDragger *) i->data;
 904         if (d == dragger)
 905             continue;
 906         d->fireDraggables (true);
 907     }
 908
 909     // make this dragger selected
 910     if (!dragger->parent->keep_selection) {
 911         dragger->parent->setSelected (dragger);
 912     }
 913     dragger->parent->keep_selection = false;
 914
 915     dragger->updateDependencies(true);
 916
 917     // we did an undoable action
 918     sp_document_done (sp_desktop_document (dragger->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 919                       _("Move gradient handle"));
 920 }
 921
 922 /**
 923 Called when a dragger knot is clicked; selects the dragger or deletes it depending on the
 924 state of the keyboard keys
 925 */
 926 static void
 927 gr_knot_clicked_handler(SPKnot */*knot*/, guint state, gpointer data)
 928 {
 929     GrDragger *dragger = (GrDragger *) data;
 930     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 931     if (!draggable) return;
 932
 933     if ( (state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK ) ) {
 934     // delete this knot from vector
 935         SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
 936         gradient = sp_gradient_get_vector (gradient, false);
 937         if (gradient->vector.stops.size() > 2) { // 2 is the minimum
 938                 SPStop *stop = NULL;
 939                 switch (draggable->point_type) {  // if we delete first or last stop, move the next/previous to the edge
 940                 case POINT_LG_BEGIN:
 941                 case POINT_RG_CENTER:
 942                     stop = sp_first_stop(gradient);
 943                         {
 944                             SPStop *next = sp_next_stop (stop);
 945                                 if (next) {
 946                                         next->offset = 0;
 947                                         sp_repr_set_css_double (SP_OBJECT_REPR (next), "offset", 0);
 948                                 }
 949                         }
 950                     break;
 951                 case POINT_LG_END:
 952                 case POINT_RG_R1:
 953                 case POINT_RG_R2:
 954                     stop = sp_last_stop(gradient);
 955                     {
 956                             SPStop *prev = sp_prev_stop (stop, gradient);
 957                             if (prev) {
 958                                     prev->offset = 1;
 959                                     sp_repr_set_css_double (SP_OBJECT_REPR (prev), "offset", 1);
 960                             }
 961                         }
 962                     break;
 963                 case POINT_LG_MID:
 964                 case POINT_RG_MID1:
 965                 case POINT_RG_MID2:
 966                     stop = sp_get_stop_i(gradient, draggable->point_i);
 967                     break;
 968                 }
 969
 970                 SP_OBJECT_REPR(gradient)->removeChild(SP_OBJECT_REPR(stop));
 971                 sp_document_done (SP_OBJECT_DOCUMENT (gradient), SP_VERB_CONTEXT_GRADIENT,
 972                                   _("Delete gradient stop"));
 973         }
 974     } else {
 975     // select the dragger
 976         dragger->point_original = dragger->point;
 977
 978         if ( state & GDK_SHIFT_MASK ) {
 979             dragger->parent->setSelected (dragger, true, false);
 980         } else {
 981             dragger->parent->setSelected (dragger);
 982         }
 983     }
 984 }
 985
 986 /**
 987 Called when a dragger knot is doubleclicked; opens gradient editor with the stop from the first draggable
 988 */
 989 static void
 990 gr_knot_doubleclicked_handler (SPKnot */*knot*/, guint /*state*/, gpointer data)
 991 {
 992     GrDragger *dragger = (GrDragger *) data;
 993
 994     dragger->point_original = dragger->point;
 995
 996     if (dragger->draggables == NULL)
 997         return;
 998
 999     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
1000     sp_item_gradient_edit_stop (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
1001 }
1002
1003 /**
1004 Act upon all draggables of the dragger, setting them to the dragger's point
1005 */
1006 void
1007 GrDragger::fireDraggables (bool write_repr, bool scale_radial, bool merging_focus)
1008 {
1009     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1010         GrDraggable *draggable = (GrDraggable *) i->data;
1011
1012         // set local_change flag so that selection_changed callback does not regenerate draggers
1013         this->parent->local_change = true;
1014
1015         // change gradient, optionally writing to repr; prevent focus from moving if it's snapped
1016         // to the center, unless it's the first update upon merge when we must snap it to the point
1017         if (merging_focus ||
1018             !(draggable->point_type == POINT_RG_FOCUS && this->isA(draggable->item, POINT_RG_CENTER, draggable->point_i, draggable->fill_or_stroke)))
1019         {
1020             sp_item_gradient_set_coords (draggable->item, draggable->point_type, draggable->point_i, this->point, draggable->fill_or_stroke, write_repr, scale_radial);
1021         }
1022     }
1023 }
1024
1025 /**
1026 Checks if the dragger has a draggable with this point_type
1027  */
1028 bool
1029 GrDragger::isA (gint point_type)
1030 {
1031     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1032         GrDraggable *draggable = (GrDraggable *) i->data;
1033         if (draggable->point_type == point_type) {
1034             return true;
1035         }
1036     }
1037     return false;
1038 }
1039
1040 /**
1041 Checks if the dragger has a draggable with this item, point_type + point_i (number), fill_or_stroke
1042  */
1043 bool
1044 GrDragger::isA (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1045 {
1046     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1047         GrDraggable *draggable = (GrDraggable *) i->data;
1048         if ( (draggable->point_type == point_type) && (draggable->point_i == point_i) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
1049             return true;
1050         }
1051     }
1052     return false;
1053 }
1054
1055 /**
1056 Checks if the dragger has a draggable with this item, point_type, fill_or_stroke
1057  */
1058 bool
1059 GrDragger::isA (SPItem *item, gint point_type, bool fill_or_stroke)
1060 {
1061     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1062         GrDraggable *draggable = (GrDraggable *) i->data;
1063         if ( (draggable->point_type == point_type) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
1064             return true;
1065         }
1066     }
1067     return false;
1068 }
1069
1070 bool
1071 GrDraggable::mayMerge (GrDraggable *da2)
1072 {
1073     if ((this->item == da2->item) && (this->fill_or_stroke == da2->fill_or_stroke)) {
1074         // we must not merge the points of the same gradient!
1075         if (!((this->point_type == POINT_RG_FOCUS && da2->point_type == POINT_RG_CENTER) ||
1076               (this->point_type == POINT_RG_CENTER && da2->point_type == POINT_RG_FOCUS))) {
1077             // except that we can snap center and focus together
1078             return false;
1079         }
1080     }
1081     // disable merging of midpoints.
1082     if ( (this->point_type == POINT_LG_MID) || (da2->point_type == POINT_LG_MID)
1083          || (this->point_type == POINT_RG_MID1) || (da2->point_type == POINT_RG_MID1)
1084          || (this->point_type == POINT_RG_MID2) || (da2->point_type == POINT_RG_MID2) )
1085         return false;
1086
1087     return true;
1088 }
1089
1090 bool
1091 GrDragger::mayMerge (GrDragger *other)
1092 {
1093     if (this == other)
1094         return false;
1095
1096     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
1097         GrDraggable *da1 = (GrDraggable *) i->data;
1098         for (GSList const* j = other->draggables; j != NULL; j = j->next) { // for all draggables of other
1099             GrDraggable *da2 = (GrDraggable *) j->data;
1100             if (!da1->mayMerge(da2))
1101                 return false;
1102         }
1103     }
1104     return true;
1105 }
1106
1107 bool
1108 GrDragger::mayMerge (GrDraggable *da2)
1109 {
1110     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
1111         GrDraggable *da1 = (GrDraggable *) i->data;
1112         if (!da1->mayMerge(da2))
1113             return false;
1114     }
1115     return true;
1116 }
1117
1118 /**
1119 Updates the statusbar tip of the dragger knot, based on its draggables
1120  */
1121 void
1122 GrDragger::updateTip ()
1123 {
1124         if (this->knot && this->knot->tip) {
1125                 g_free (this->knot->tip);
1126                 this->knot->tip = NULL;
1127         }
1128
1129     if (g_slist_length (this->draggables) == 1) {
1130         GrDraggable *draggable = (GrDraggable *) this->draggables->data;
1131         char *item_desc = sp_item_description(draggable->item);
1132         switch (draggable->point_type) {
1133             case POINT_LG_MID:
1134             case POINT_RG_MID1:
1135             case POINT_RG_MID2:
1136                 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"),
1137                                                    _(gr_knot_descr[draggable->point_type]),
1138                                                    draggable->point_i,
1139                                                    item_desc,
1140                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
1141                 break;
1142
1143             default:
1144                 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"),
1145                                                    _(gr_knot_descr[draggable->point_type]),
1146                                                    item_desc,
1147                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
1148                 break;
1149         }
1150         g_free(item_desc);
1151     } else if (g_slist_length (draggables) == 2 && isA (POINT_RG_CENTER) && isA (POINT_RG_FOCUS)) {
1152         this->knot->tip = g_strdup_printf (_("Radial gradient <b>center</b> and <b>focus</b>; drag with <b>Shift</b> to separate focus"));
1153     } else {
1154         int length = g_slist_length (this->draggables);
1155         this->knot->tip = g_strdup_printf (ngettext("Gradient point shared by <b>%d</b> gradient; drag with <b>Shift</b> to separate",
1156                                                     "Gradient point shared by <b>%d</b> gradients; drag with <b>Shift</b> to separate",
1157                                                     length),
1158                                            length);
1159     }
1160 }
1161
1162 /**
1163 Adds a draggable to the dragger
1164  */
1165 void
1166 GrDragger::updateKnotShape ()
1167 {
1168     if (!draggables)
1169         return;
1170     GrDraggable *last = (GrDraggable *) g_slist_last(draggables)->data;
1171     g_object_set (G_OBJECT (this->knot->item), "shape", gr_knot_shapes[last->point_type], NULL);
1172 }
1173
1174 /**
1175 Adds a draggable to the dragger
1176  */
1177 void
1178 GrDragger::addDraggable (GrDraggable *draggable)
1179 {
1180     this->draggables = g_slist_prepend (this->draggables, draggable);
1181
1182     this->updateTip();
1183 }
1184
1185
1186 /**
1187 Moves this dragger to the point of the given draggable, acting upon all other draggables
1188  */
1189 void
1190 GrDragger::moveThisToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1191 {
1192     this->point = sp_item_gradient_get_coords (item, point_type, point_i, fill_or_stroke);
1193     this->point_original = this->point;
1194
1195     sp_knot_moveto (this->knot, &(this->point));
1196
1197     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1198         GrDraggable *da = (GrDraggable *) i->data;
1199         if ( (da->item == item) &&
1200              (point_type == -1 || da->point_type == point_type) &&
1201              (point_i == -1 || da->point_i == point_i) &&
1202              (da->fill_or_stroke == fill_or_stroke) ) {
1203             continue;
1204         }
1205         sp_item_gradient_set_coords (da->item, da->point_type, da->point_i, this->point, da->fill_or_stroke, write_repr, false);
1206     }
1207     // FIXME: here we should also call this->updateDependencies(write_repr); to propagate updating, but how to prevent loops?
1208 }
1209
1210
1211 /**
1212 Moves all midstop draggables that depend on this one
1213  */
1214 void
1215 GrDragger::updateMidstopDependencies (GrDraggable *draggable, bool write_repr) {
1216     SPObject *server = draggable->getServer();
1217     if (!server)
1218         return;
1219     guint num = SP_GRADIENT(server)->vector.stops.size();
1220     if (num <= 2) return;
1221
1222     if ( SP_IS_LINEARGRADIENT(server) ) {
1223         for ( guint i = 1; i < num - 1; i++ ) {
1224             this->moveOtherToDraggable (draggable->item, POINT_LG_MID, i, draggable->fill_or_stroke, write_repr);
1225         }
1226     } else  if ( SP_IS_RADIALGRADIENT(server) ) {
1227         for ( guint i = 1; i < num - 1; i++ ) {
1228             this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, i, draggable->fill_or_stroke, write_repr);
1229             this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, i, draggable->fill_or_stroke, write_repr);
1230         }
1231     }
1232 }
1233
1234
1235 /**
1236 Moves all draggables that depend on this one
1237  */
1238 void
1239 GrDragger::updateDependencies (bool write_repr)
1240 {
1241     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1242         GrDraggable *draggable = (GrDraggable *) i->data;
1243         switch (draggable->point_type) {
1244             case POINT_LG_BEGIN:
1245                 {
1246                     // the end point is dependent only when dragging with ctrl+shift
1247                     this->moveOtherToDraggable (draggable->item, POINT_LG_END, -1, draggable->fill_or_stroke, write_repr);
1248
1249                     this->updateMidstopDependencies (draggable, write_repr);
1250                 }
1251                 break;
1252             case POINT_LG_END:
1253                 {
1254                     // the begin point is dependent only when dragging with ctrl+shift
1255                     this->moveOtherToDraggable (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke, write_repr);
1256
1257                     this->updateMidstopDependencies (draggable, write_repr);
1258                 }
1259                 break;
1260             case POINT_LG_MID:
1261                 // no other nodes depend on mid points.
1262                 break;
1263             case POINT_RG_R2:
1264                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1265                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1266                 this->updateMidstopDependencies (draggable, write_repr);
1267                 break;
1268             case POINT_RG_R1:
1269                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1270                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1271                 this->updateMidstopDependencies (draggable, write_repr);
1272                 break;
1273             case POINT_RG_CENTER:
1274                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1275                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1276                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1277                 this->updateMidstopDependencies (draggable, write_repr);
1278                 break;
1279             case POINT_RG_FOCUS:
1280                 // nothing can depend on that
1281                 break;
1282             case POINT_RG_MID1:
1283                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, draggable->point_i, draggable->fill_or_stroke, write_repr);
1284                 break;
1285             case POINT_RG_MID2:
1286                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, draggable->point_i, draggable->fill_or_stroke, write_repr);
1287                 break;
1288             default:
1289                 break;
1290         }
1291     }
1292 }
1293
1294
1295
1296 GrDragger::GrDragger (GrDrag *parent, NR::Point p, GrDraggable *draggable)
1297 {
1298     this->draggables = NULL;
1299
1300     this->parent = parent;
1301
1302     this->point = p;
1303     this->point_original = p;
1304
1305     // create the knot
1306     this->knot = sp_knot_new (parent->desktop, NULL);
1307     this->knot->setMode(SP_KNOT_MODE_XOR);
1308     this->knot->setFill(GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_MOUSEOVER, GR_KNOT_COLOR_MOUSEOVER);
1309     this->knot->setStroke(0x000000ff, 0x000000ff, 0x000000ff);
1310     sp_knot_update_ctrl(this->knot);
1311
1312     // move knot to the given point
1313     sp_knot_set_position (this->knot, &p, SP_KNOT_STATE_NORMAL);
1314     sp_knot_show (this->knot);
1315
1316     // connect knot's signals
1317     if ( (draggable)  // it can be NULL if a node in unsnapped (eg. focus point unsnapped from center)
1318                        // luckily, midstops never snap to other nodes so are never unsnapped...
1319          && ( (draggable->point_type == POINT_LG_MID)
1320               || (draggable->point_type == POINT_RG_MID1)
1321               || (draggable->point_type == POINT_RG_MID2) ) )
1322     {
1323         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_midpoint_handler), this);
1324     } else {
1325         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_handler), this);
1326     }
1327     g_signal_connect (G_OBJECT (this->knot), "clicked", G_CALLBACK (gr_knot_clicked_handler), this);
1328     g_signal_connect (G_OBJECT (this->knot), "doubleclicked", G_CALLBACK (gr_knot_doubleclicked_handler), this);
1329     g_signal_connect (G_OBJECT (this->knot), "grabbed", G_CALLBACK (gr_knot_grabbed_handler), this);
1330     g_signal_connect (G_OBJECT (this->knot), "ungrabbed", G_CALLBACK (gr_knot_ungrabbed_handler), this);
1331
1332     // add the initial draggable
1333     if (draggable)
1334         this->addDraggable (draggable);
1335     updateKnotShape();
1336 }
1337
1338 GrDragger::~GrDragger ()
1339 {
1340     // unselect if it was selected
1341     this->parent->setDeselected(this);
1342
1343     // disconnect signals
1344     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_moved_handler), this);
1345     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_clicked_handler), this);
1346     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_doubleclicked_handler), this);
1347     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_grabbed_handler), this);
1348     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_ungrabbed_handler), this);
1349
1350     /* unref should call destroy */
1351     g_object_unref (G_OBJECT (this->knot));
1352
1353     // delete all draggables
1354     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1355         delete ((GrDraggable *) i->data);
1356     }
1357     g_slist_free (this->draggables);
1358     this->draggables = NULL;
1359 }
1360
1361 /**
1362 Select the dragger which has the given draggable.
1363 */
1364 GrDragger *
1365 GrDrag::getDraggerFor (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1366 {
1367     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1368         GrDragger *dragger = (GrDragger *) i->data;
1369         for (GSList const* j = dragger->draggables; j != NULL; j = j->next) {
1370             GrDraggable *da2 = (GrDraggable *) j->data;
1371             if ( (da2->item == item) &&
1372                  (point_type == -1 || da2->point_type == point_type) && // -1 means this does not matter
1373                  (point_i == -1 || da2->point_i == point_i) && // -1 means this does not matter
1374                  (da2->fill_or_stroke == fill_or_stroke)) {
1375                 return (dragger);
1376             }
1377         }
1378     }
1379     return NULL;
1380 }
1381
1382
1383 void
1384 GrDragger::moveOtherToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1385 {
1386     GrDragger *d = this->parent->getDraggerFor (item, point_type, point_i, fill_or_stroke);
1387     if (d && d !=  this) {
1388         d->moveThisToDraggable (item, point_type, point_i, fill_or_stroke, write_repr);
1389     }
1390 }
1391
1392
1393 /**
1394   Draw this dragger as selected
1395 */
1396 void
1397 GrDragger::select()
1398 {
1399     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_SELECTED;
1400     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_SELECTED, NULL);
1401 }
1402
1403 /**
1404   Draw this dragger as normal (deselected)
1405 */
1406 void
1407 GrDragger::deselect()
1408 {
1409     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_NORMAL;
1410     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_NORMAL, NULL);
1411 }
1412
1413 bool
1414 GrDragger::isSelected()
1415 {
1416     return g_list_find (parent->selected, this);
1417 }
1418
1419 /**
1420 \brief Deselect all stops/draggers (private)
1421 */
1422 void
1423 GrDrag::deselect_all()
1424 {
1425     while (selected) {
1426         ( (GrDragger*) selected->data)->deselect();
1427         selected = g_list_remove(selected, selected->data);
1428     }
1429 }
1430
1431 /**
1432 \brief Deselect all stops/draggers (public; emits signal)
1433 */
1434 void
1435 GrDrag::deselectAll()
1436 {
1437     deselect_all();
1438     this->desktop->emitToolSubselectionChanged(NULL);
1439 }
1440
1441 /**
1442 \brief Select all stops/draggers
1443 */
1444 void
1445 GrDrag::selectAll()
1446 {
1447     for (GList *l = this->draggers; l != NULL; l = l->next) {
1448         GrDragger *d = ((GrDragger *) l->data);
1449         setSelected (d, true, true);
1450     }
1451 }
1452
1453 /**
1454 \brief Select all stops/draggers that match the coords
1455 */
1456 void
1457 GrDrag::selectByCoords(std::vector<NR::Point> coords)
1458 {
1459     for (GList *l = this->draggers; l != NULL; l = l->next) {
1460         GrDragger *d = ((GrDragger *) l->data);
1461         for (guint k = 0; k < coords.size(); k++) {
1462             if (NR::L2 (d->point - coords[k]) < 1e-4) {
1463                 setSelected (d, true, true);
1464             }
1465         }
1466     }
1467 }
1468
1469
1470 /**
1471 \brief Select all stops/draggers that fall within the rect
1472 */
1473 void
1474 GrDrag::selectRect(NR::Rect const &r)
1475 {
1476     for (GList *l = this->draggers; l != NULL; l = l->next) {
1477         GrDragger *d = ((GrDragger *) l->data);
1478         if (r.contains(d->point)) {
1479            setSelected (d, true, true);
1480         }
1481     }
1482 }
1483
1484 /**
1485 \brief Select a dragger
1486 \param dragger       The dragger to select
1487 \param add_to_selection   If true, add to selection, otherwise deselect others
1488 \param override      If true, always select this node, otherwise toggle selected status
1489 */
1490 void
1491 GrDrag::setSelected (GrDragger *dragger, bool add_to_selection, bool override)
1492 {
1493     GrDragger *seldragger = NULL;
1494
1495     if (add_to_selection) {
1496         if (!dragger) return;
1497         if (override) {
1498             if (!g_list_find(selected, dragger)) {
1499                 selected = g_list_prepend(selected, dragger);
1500             }
1501             dragger->select();
1502             seldragger = dragger;
1503         } else { // toggle
1504             if (g_list_find(selected, dragger)) {
1505                 selected = g_list_remove(selected, dragger);
1506                 dragger->deselect();
1507                 if (selected) {
1508                     seldragger = (GrDragger*) selected->data; // select the dragger that is first in the list
1509                 }
1510             } else {
1511                 selected = g_list_prepend(selected, dragger);
1512                 dragger->select();
1513                 seldragger = dragger;
1514             }
1515         }
1516     } else {
1517         deselect_all();
1518         if (dragger) {
1519             selected = g_list_prepend(selected, dragger);
1520             dragger->select();
1521             seldragger = dragger;
1522         }
1523     }
1524     if (seldragger) {
1525         this->desktop->emitToolSubselectionChanged((gpointer) seldragger);
1526     }
1527 }
1528
1529 /**
1530 \brief Deselect a dragger
1531 \param dragger       The dragger to deselect
1532 */
1533 void
1534 GrDrag::setDeselected (GrDragger *dragger)
1535 {
1536     if (g_list_find(selected, dragger)) {
1537         selected = g_list_remove(selected, dragger);
1538         dragger->deselect();
1539     }
1540     this->desktop->emitToolSubselectionChanged((gpointer) (selected ? selected->data : NULL ));
1541 }
1542
1543
1544
1545 /**
1546 Create a line from p1 to p2 and add it to the lines list
1547  */
1548 void
1549 GrDrag::addLine (SPItem *item, NR::Point p1, NR::Point p2, guint32 rgba)
1550 {
1551     SPCanvasItem *line = sp_canvas_item_new(sp_desktop_controls(this->desktop),
1552                                                             SP_TYPE_CTRLLINE, NULL);
1553     SP_CTRLLINE(line)->item = item;
1554     sp_ctrlline_set_coords(SP_CTRLLINE(line), p1, p2);
1555     if (rgba != GR_LINE_COLOR_FILL) // fill is the default, so don't set color for it to speed up redraw
1556         sp_ctrlline_set_rgba32 (SP_CTRLLINE(line), rgba);
1557     sp_canvas_item_show (line);
1558     this->lines = g_slist_append (this->lines, line);
1559 }
1560
1561 /**
1562 If there already exists a dragger within MERGE_DIST of p, add the draggable to it; otherwise create
1563 new dragger and add it to draggers list
1564  */
1565 void
1566 GrDrag::addDragger (GrDraggable *draggable)
1567 {
1568     NR::Point p = sp_item_gradient_get_coords (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
1569
1570     for (GList *i = this->draggers; i != NULL; i = i->next) {
1571         GrDragger *dragger = (GrDragger *) i->data;
1572         if (dragger->mayMerge (draggable) && NR::L2 (dragger->point - p) < MERGE_DIST) {
1573             // distance is small, merge this draggable into dragger, no need to create new dragger
1574             dragger->addDraggable (draggable);
1575             dragger->updateKnotShape();
1576             return;
1577         }
1578     }
1579
1580     GrDragger *new_dragger = new GrDragger(this, p, draggable);
1581     // fixme: draggers should be added AFTER the last one: this way tabbing through them will be from begin to end.
1582     this->draggers = g_list_append (this->draggers, new_dragger);
1583 }
1584
1585 /**
1586 Add draggers for the radial gradient rg on item
1587 */
1588 void
1589 GrDrag::addDraggersRadial (SPRadialGradient *rg, SPItem *item, bool fill_or_stroke)
1590 {
1591     addDragger (new GrDraggable (item, POINT_RG_CENTER, 0, fill_or_stroke));
1592     guint num = rg->vector.stops.size();
1593     if (num > 2) {
1594         for ( guint i = 1; i < num - 1; i++ ) {
1595             addDragger (new GrDraggable (item, POINT_RG_MID1, i, fill_or_stroke));
1596         }
1597     }
1598     addDragger (new GrDraggable (item, POINT_RG_R1, num-1, fill_or_stroke));
1599     if (num > 2) {
1600         for ( guint i = 1; i < num - 1; i++ ) {
1601             addDragger (new GrDraggable (item, POINT_RG_MID2, i, fill_or_stroke));
1602         }
1603     }
1604     addDragger (new GrDraggable (item, POINT_RG_R2, num-1, fill_or_stroke));
1605     addDragger (new GrDraggable (item, POINT_RG_FOCUS, 0, fill_or_stroke));
1606 }
1607
1608 /**
1609 Add draggers for the linear gradient lg on item
1610 */
1611 void
1612 GrDrag::addDraggersLinear (SPLinearGradient *lg, SPItem *item, bool fill_or_stroke)
1613 {
1614     addDragger (new GrDraggable (item, POINT_LG_BEGIN, 0, fill_or_stroke));
1615     guint num = lg->vector.stops.size();
1616     if (num > 2) {
1617         for ( guint i = 1; i < num - 1; i++ ) {
1618             addDragger (new GrDraggable (item, POINT_LG_MID, i, fill_or_stroke));
1619         }
1620     }
1621     addDragger (new GrDraggable (item, POINT_LG_END, num-1, fill_or_stroke));
1622 }
1623
1624 /**
1625 Artificially grab the knot of this dragger; used by the gradient context
1626 */
1627 void
1628 GrDrag::grabKnot (GrDragger *dragger, gint x, gint y, guint32 etime)
1629 {
1630     if (dragger) {
1631         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1632     }
1633 }
1634
1635 /**
1636 Artificially grab the knot of the dragger with this draggable; used by the gradient context
1637 */
1638 void
1639 GrDrag::grabKnot (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, gint x, gint y, guint32 etime)
1640 {
1641     GrDragger *dragger = getDraggerFor (item, point_type, point_i, fill_or_stroke);
1642     if (dragger) {
1643         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1644     }
1645 }
1646
1647 /**
1648 Regenerates the draggers list from the current selection; is called when selection is changed or
1649 modified, also when a radial dragger needs to update positions of other draggers in the gradient
1650 */
1651 void
1652 GrDrag::updateDraggers ()
1653 {
1654     while (selected) {
1655         selected = g_list_remove(selected, selected->data);
1656     }
1657     // delete old draggers
1658     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1659         delete ((GrDragger *) i->data);
1660     }
1661     g_list_free (this->draggers);
1662     this->draggers = NULL;
1663
1664     g_return_if_fail (this->selection != NULL);
1665
1666     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1667
1668         SPItem *item = SP_ITEM(i->data);
1669         SPStyle *style = SP_OBJECT_STYLE (item);
1670
1671         if (style && (style->fill.isPaintserver())) {
1672             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1673             if (SP_IS_LINEARGRADIENT (server)) {
1674                 addDraggersLinear (SP_LINEARGRADIENT (server), item, true);
1675             } else if (SP_IS_RADIALGRADIENT (server)) {
1676                 addDraggersRadial (SP_RADIALGRADIENT (server), item, true);
1677             }
1678         }
1679
1680         if (style && (style->stroke.isPaintserver())) {
1681             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1682             if (SP_IS_LINEARGRADIENT (server)) {
1683                 addDraggersLinear (SP_LINEARGRADIENT (server), item, false);
1684             } else if (SP_IS_RADIALGRADIENT (server)) {
1685                 addDraggersRadial (SP_RADIALGRADIENT (server), item, false);
1686             }
1687         }
1688     }
1689 }
1690
1691 /**
1692 Regenerates the lines list from the current selection; is called on each move of a dragger, so that
1693 lines are always in sync with the actual gradient
1694 */
1695 void
1696 GrDrag::updateLines ()
1697 {
1698     // delete old lines
1699     for (GSList const *i = this->lines; i != NULL; i = i->next) {
1700         gtk_object_destroy( GTK_OBJECT (i->data));
1701     }
1702     g_slist_free (this->lines);
1703     this->lines = NULL;
1704
1705     g_return_if_fail (this->selection != NULL);
1706
1707     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1708
1709         SPItem *item = SP_ITEM(i->data);
1710
1711         SPStyle *style = SP_OBJECT_STYLE (item);
1712
1713         if (style && (style->fill.isPaintserver())) {
1714             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1715             if (SP_IS_LINEARGRADIENT (server)) {
1716                 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);
1717             } else if (SP_IS_RADIALGRADIENT (server)) {
1718                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, true);
1719                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, true), GR_LINE_COLOR_FILL);
1720                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, true), GR_LINE_COLOR_FILL);
1721             }
1722         }
1723
1724         if (style && (style->stroke.isPaintserver())) {
1725             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1726             if (SP_IS_LINEARGRADIENT (server)) {
1727                 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);
1728             } else if (SP_IS_RADIALGRADIENT (server)) {
1729                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, false);
1730                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, false), GR_LINE_COLOR_STROKE);
1731                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, false), GR_LINE_COLOR_STROKE);
1732             }
1733         }
1734     }
1735 }
1736
1737 /**
1738 Regenerates the levels list from the current selection
1739 */
1740 void
1741 GrDrag::updateLevels ()
1742 {
1743     hor_levels.clear();
1744     vert_levels.clear();
1745
1746     g_return_if_fail (this->selection != NULL);
1747
1748     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1749         SPItem *item = SP_ITEM(i->data);
1750         NR::Maybe<NR::Rect> rect = sp_item_bbox_desktop (item);
1751         if (rect) {
1752             // Remember the edges of the bbox and the center axis
1753             hor_levels.push_back(rect->min()[NR::Y]);
1754             hor_levels.push_back(rect->max()[NR::Y]);
1755             hor_levels.push_back(0.5 * (rect->min()[NR::Y] + rect->max()[NR::Y]));
1756             vert_levels.push_back(rect->min()[NR::X]);
1757             vert_levels.push_back(rect->max()[NR::X]);
1758             vert_levels.push_back(0.5 * (rect->min()[NR::X] + rect->max()[NR::X]));
1759         }
1760     }
1761 }
1762
1763 void
1764 GrDrag::selected_reverse_vector ()
1765 {
1766     if (selected == NULL)
1767         return;
1768
1769     for (GSList const* i = ( (GrDragger*) selected->data )->draggables; i != NULL; i = i->next) {
1770         GrDraggable *draggable = (GrDraggable *) i->data;
1771
1772         sp_item_gradient_reverse_vector (draggable->item, draggable->fill_or_stroke);
1773     }
1774 }
1775
1776 void
1777 GrDrag::selected_move_nowrite (double x, double y, bool scale_radial)
1778 {
1779     selected_move (x, y, false, scale_radial);
1780 }
1781
1782 void
1783 GrDrag::selected_move (double x, double y, bool write_repr, bool scale_radial)
1784 {
1785     if (selected == NULL)
1786         return;
1787
1788     bool did = false;
1789
1790     for (GList *i = selected; i != NULL; i = i->next) {
1791         GrDragger *d = (GrDragger *) i->data;
1792
1793         if (!d->isA(POINT_LG_MID) && !d->isA(POINT_RG_MID1) && !d->isA(POINT_RG_MID2)) {
1794             // if this is an endpoint,
1795
1796             // Moving an rg center moves its focus and radii as well.
1797             // therefore, if this is a focus or radius and if selection
1798             // contains the center as well, do not move this one
1799             if (d->isA(POINT_RG_R1) || d->isA(POINT_RG_R2) ||
1800                 (d->isA(POINT_RG_FOCUS) && !d->isA(POINT_RG_CENTER))) {
1801                 bool skip_radius_with_center = false;
1802                 for (GList *di = selected; di != NULL; di = di->next) {
1803                     GrDragger *d_new = (GrDragger *) di->data;
1804                     if (d_new->isA (((GrDraggable *) d->draggables->data)->item,
1805                                     POINT_RG_CENTER,
1806                                     0,
1807                                     ((GrDraggable *) d->draggables->data)->fill_or_stroke)) {
1808                         // FIXME: here we take into account only the first draggable!
1809                         skip_radius_with_center = true;
1810                     }
1811                 }
1812                 if (skip_radius_with_center)
1813                     continue;
1814             }
1815
1816             did = true;
1817             d->point += NR::Point (x, y);
1818             d->point_original = d->point;
1819             sp_knot_moveto (d->knot, &(d->point));
1820
1821             d->fireDraggables (write_repr, scale_radial);
1822
1823             d->updateDependencies(write_repr);
1824         }
1825     }
1826
1827     if (write_repr && did) {
1828         // we did an undoable action
1829         sp_document_maybe_done (sp_desktop_document (desktop), "grmoveh", SP_VERB_CONTEXT_GRADIENT,
1830                                 _("Move gradient handle(s)"));
1831         return;
1832     }
1833
1834     if (!did) { // none of the end draggers are selected, so let's try to move the mids
1835
1836         GrDragger *dragger = (GrDragger *) selected->data;
1837         // a midpoint dragger can (logically) only contain one GrDraggable
1838         GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
1839
1840         NR::Point begin(0,0), end(0,0);
1841         NR::Point low_lim(0,0), high_lim(0,0);
1842
1843         SPObject *server = draggable->getServer();
1844         GSList *moving = NULL;
1845         gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
1846
1847         NR::Point p(x, y);
1848         p = snap_vector_midpoint (dragger->point + p, low_lim, high_lim, 0);
1849         NR::Point displacement = p - dragger->point;
1850
1851         for (GSList const* i = moving; i != NULL; i = i->next) {
1852             GrDragger *drg = (GrDragger*) i->data;
1853             SPKnot *drgknot = drg->knot;
1854             drg->point += displacement;
1855             sp_knot_moveto (drgknot, & drg->point);
1856             drg->fireDraggables (true);
1857             drg->updateDependencies(true);
1858             did = true;
1859         }
1860
1861         g_slist_free(moving);
1862
1863         if (write_repr && did) {
1864             // we did an undoable action
1865             sp_document_maybe_done (sp_desktop_document (desktop), "grmovem", SP_VERB_CONTEXT_GRADIENT,
1866                                     _("Move gradient mid stop(s)"));
1867         }
1868     }
1869 }
1870
1871 void
1872 GrDrag::selected_move_screen (double x, double y)
1873 {
1874     gdouble zoom = desktop->current_zoom();
1875     gdouble zx = x / zoom;
1876     gdouble zy = y / zoom;
1877
1878     selected_move (zx, zy);
1879 }
1880
1881 /**
1882 Select the knot next to the last selected one and deselect all other selected.
1883 */
1884 GrDragger *
1885 GrDrag::select_next ()
1886 {
1887     GrDragger *d = NULL;
1888     if (selected == NULL || g_list_find(draggers, selected->data)->next == NULL) {
1889         if (draggers)
1890             d = (GrDragger *) draggers->data;
1891     } else {
1892         d = (GrDragger *) g_list_find(draggers, selected->data)->next->data;
1893     }
1894     if (d)
1895         setSelected (d);
1896     return d;
1897 }
1898
1899 /**
1900 Select the knot previous from the last selected one and deselect all other selected.
1901 */
1902 GrDragger *
1903 GrDrag::select_prev ()
1904 {
1905     GrDragger *d = NULL;
1906     if (selected == NULL || g_list_find(draggers, selected->data)->prev == NULL) {
1907         if (draggers)
1908             d = (GrDragger *) g_list_last (draggers)->data;
1909     } else {
1910         d = (GrDragger *) g_list_find(draggers, selected->data)->prev->data;
1911     }
1912     if (d)
1913         setSelected (d);
1914     return d;
1915 }
1916
1917
1918 // FIXME: i.m.o. an ugly function that I just made to work, but... aargh! (Johan)
1919 void
1920 GrDrag::deleteSelected (bool just_one)
1921 {
1922     if (!selected) return;
1923
1924     SPDocument *document = false;
1925
1926     struct StructStopInfo {
1927         SPStop * spstop;
1928         GrDraggable * draggable;
1929         SPGradient * gradient;
1930         SPGradient * vector;
1931     };
1932
1933     GSList *midstoplist = NULL;  // list of stops that must be deleted (will be deleted first)
1934     GSList *endstoplist = NULL;  // list of stops that must be deleted
1935     while (selected) {
1936         GrDragger *dragger = (GrDragger*) selected->data;
1937         for (GSList * drgble = dragger->draggables; drgble != NULL; drgble = drgble->next) {
1938             GrDraggable *draggable = (GrDraggable*) drgble->data;
1939             SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
1940             SPGradient *vector   = sp_gradient_get_forked_vector_if_necessary (gradient, false);
1941
1942             switch (draggable->point_type) {
1943                 case POINT_LG_MID:
1944                 case POINT_RG_MID1:
1945                 case POINT_RG_MID2:
1946                     {
1947                         SPStop *stop = sp_get_stop_i(vector, draggable->point_i);
1948                         // check if already present in list. (e.g. when both RG_MID1 and RG_MID2 were selected)
1949                         bool present = false;
1950                         for (GSList const * l = midstoplist; l != NULL; l = l->next) {
1951                             if ( (SPStop*)l->data == stop ) {
1952                                 present = true;
1953                                 break; // no need to search further.
1954                             }
1955                         }
1956                         if (!present)
1957                             midstoplist = g_slist_append(midstoplist, stop);
1958                     }
1959                     break;
1960                 case POINT_LG_BEGIN:
1961                 case POINT_LG_END:
1962                 case POINT_RG_CENTER:
1963                 case POINT_RG_R1:
1964                 case POINT_RG_R2:
1965                     {
1966                         SPStop *stop = NULL;
1967                         if ( (draggable->point_type == POINT_LG_BEGIN) || (draggable->point_type == POINT_RG_CENTER) ) {
1968                             stop = sp_first_stop(vector);
1969                         } else {
1970                             stop = sp_last_stop(vector);
1971                         }
1972                         if (stop) {
1973                             StructStopInfo *stopinfo = new StructStopInfo;
1974                             stopinfo->spstop = stop;
1975                             stopinfo->draggable = draggable;
1976                             stopinfo->gradient = gradient;
1977                             stopinfo->vector = vector;
1978                             // check if already present in list. (e.g. when both R1 and R2 were selected)
1979                             bool present = false;
1980                             for (GSList const * l = endstoplist; l != NULL; l = l->next) {
1981                                 if ( ((StructStopInfo*)l->data)->spstop == stopinfo->spstop ) {
1982                                     present = true;
1983                                     break; // no need to search further.
1984                                 }
1985                             }
1986                             if (!present)
1987                                 endstoplist = g_slist_append(endstoplist, stopinfo);
1988                         }
1989                     }
1990                     break;
1991                 default:
1992                     break;
1993             }
1994         }
1995         selected = g_list_remove(selected, dragger);
1996         if ( just_one ) break; // iterate once if just_one is set.
1997     }
1998     while (midstoplist) {
1999         SPStop *stop = (SPStop*) midstoplist->data;
2000         document = SP_OBJECT_DOCUMENT (stop);
2001         Inkscape::XML::Node * parent = SP_OBJECT_REPR(stop)->parent();
2002         parent->removeChild(SP_OBJECT_REPR(stop));
2003         midstoplist = g_slist_remove(midstoplist, stop);
2004     }
2005     while (endstoplist) {
2006         StructStopInfo *stopinfo  = (StructStopInfo*) endstoplist->data;
2007         document = SP_OBJECT_DOCUMENT (stopinfo->spstop);
2008
2009         // 2 is the minimum, cannot delete more than that without deleting the whole vector
2010         // cannot use vector->vector.stops.size() because the vector might be invalidated by deletion of a midstop
2011         // manually count the children, don't know if there already exists a function for this...
2012         int len = 0;
2013         for ( SPObject *child = sp_object_first_child(stopinfo->vector) ;
2014               child != NULL ;
2015               child = SP_OBJECT_NEXT(child) )
2016         {
2017             if ( SP_IS_STOP(child) )  len ++;
2018         }
2019         if (len > 2)
2020         {
2021             switch (stopinfo->draggable->point_type) {
2022                 case POINT_LG_BEGIN:
2023                     {
2024                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2025
2026                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
2027                         NR::Point oldbegin = NR::Point (lg->x1.computed, lg->y1.computed);
2028                         NR::Point end = NR::Point (lg->x2.computed, lg->y2.computed);
2029                         SPStop *stop = sp_first_stop(stopinfo->vector);
2030                         gdouble offset = stop->offset;
2031                         NR::Point newbegin = oldbegin + offset * (end - oldbegin);
2032                         lg->x1.computed = newbegin[NR::X];
2033                         lg->y1.computed = newbegin[NR::Y];
2034
2035                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
2036                         sp_repr_set_svg_double(repr, "x1", lg->x1.computed);
2037                         sp_repr_set_svg_double(repr, "y1", lg->y1.computed);
2038                         stop->offset = 0;
2039                         sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", 0);
2040
2041                         // iterate through midstops to set new offset values such that they won't move on canvas.
2042                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2043                         stop = sp_next_stop(stop);
2044                         while ( stop != laststop ) {
2045                             stop->offset = (stop->offset - offset)/(1 - offset);
2046                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2047                             stop = sp_next_stop(stop);
2048                         }
2049                     }
2050                     break;
2051                 case POINT_LG_END:
2052                     {
2053                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2054
2055                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
2056                         NR::Point begin = NR::Point (lg->x1.computed, lg->y1.computed);
2057                         NR::Point oldend = NR::Point (lg->x2.computed, lg->y2.computed);
2058                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2059                         gdouble offset = laststop->offset;
2060                         NR::Point newend = begin + offset * (oldend - begin);
2061                         lg->x2.computed = newend[NR::X];
2062                         lg->y2.computed = newend[NR::Y];
2063
2064                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
2065                         sp_repr_set_svg_double(repr, "x2", lg->x2.computed);
2066                         sp_repr_set_svg_double(repr, "y2", lg->y2.computed);
2067                         laststop->offset = 1;
2068                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
2069
2070                         // iterate through midstops to set new offset values such that they won't move on canvas.
2071                         SPStop *stop = sp_first_stop(stopinfo->vector);
2072                         stop = sp_next_stop(stop);
2073                         while ( stop != laststop ) {
2074                             stop->offset = stop->offset / offset;
2075                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2076                             stop = sp_next_stop(stop);
2077                         }
2078                     }
2079                     break;
2080                 case POINT_RG_CENTER:
2081                     {
2082                         SPStop *newfirst = sp_next_stop (stopinfo->spstop);
2083                         if (newfirst) {
2084                             newfirst->offset = 0;
2085                             sp_repr_set_css_double (SP_OBJECT_REPR (newfirst), "offset", 0);
2086                         }
2087                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2088                     }
2089                     break;
2090                 case POINT_RG_R1:
2091                 case POINT_RG_R2:
2092                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2093
2094                         SPRadialGradient *rg = SP_RADIALGRADIENT(stopinfo->gradient);
2095                         double oldradius = rg->r.computed;
2096                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2097                         gdouble offset = laststop->offset;
2098                         double newradius = offset * oldradius;
2099                         rg->r.computed = newradius;
2100
2101                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(rg);
2102                         sp_repr_set_svg_double(repr, "r", rg->r.computed);
2103                         laststop->offset = 1;
2104                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
2105
2106                         // iterate through midstops to set new offset values such that they won't move on canvas.
2107                         SPStop *stop = sp_first_stop(stopinfo->vector);
2108                         stop = sp_next_stop(stop);
2109                         while ( stop != laststop ) {
2110                             stop->offset = stop->offset / offset;
2111                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2112                             stop = sp_next_stop(stop);
2113                         }
2114                         break;
2115             }
2116         }
2117         else
2118         { // delete the gradient from the object. set fill to unset  FIXME: set to fill of unselected node?
2119             SPCSSAttr *css = sp_repr_css_attr_new ();
2120
2121             // stopinfo->spstop is the selected stop
2122             Inkscape::XML::Node *unselectedrepr = SP_OBJECT_REPR(stopinfo->vector)->firstChild();
2123             if (unselectedrepr == SP_OBJECT_REPR(stopinfo->spstop) ) {
2124                 unselectedrepr = unselectedrepr->next();
2125             }
2126
2127             if (unselectedrepr == NULL) {
2128                 if (stopinfo->draggable->fill_or_stroke) {
2129                     sp_repr_css_unset_property (css, "fill");
2130                 } else {
2131                     sp_repr_css_unset_property (css, "stroke");
2132                 }
2133             } else {
2134                 SPCSSAttr *stopcss = sp_repr_css_attr(unselectedrepr, "style");
2135                 if (stopinfo->draggable->fill_or_stroke) {
2136                     sp_repr_css_set_property(css, "fill", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
2137                     sp_repr_css_set_property(css, "fill-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
2138                 } else {
2139                     sp_repr_css_set_property(css, "stroke", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
2140                     sp_repr_css_set_property(css, "stroke-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
2141                 }
2142                 sp_repr_css_attr_unref (stopcss);
2143             }
2144
2145             sp_repr_css_change (SP_OBJECT_REPR (stopinfo->draggable->item), css, "style");
2146             sp_repr_css_attr_unref (css);
2147         }
2148
2149         endstoplist = g_slist_remove(endstoplist, stopinfo);
2150         delete stopinfo;
2151     }
2152
2153     if (document) {
2154         sp_document_done ( document, SP_VERB_CONTEXT_GRADIENT, _("Delete gradient stop(s)") );
2155     }
2156 }
2157
2158
2159 /*
2160   Local Variables:
2161   mode:c++
2162   c-file-style:"stroustrup"
2163   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
2164   indent-tabs-mode:nil
2165   fill-column:99
2166   End:
2167 */
2168 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :