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
  47
  48 #define GR_KNOT_COLOR_NORMAL 0xffffff00
  49 #define GR_KNOT_COLOR_MOUSEOVER 0xff000000
  50 #define GR_KNOT_COLOR_SELECTED 0x0000ff00
  51
  52 #define GR_LINE_COLOR_FILL 0x0000ff7f
  53 #define GR_LINE_COLOR_STROKE 0x9999007f
  54
  55 // screen pixels between knots when they snap:
  56 #define SNAP_DIST 5
  57
  58 // absolute distance between gradient points for them to become a single dragger when the drag is created:
  59 #define MERGE_DIST 0.1
  60
  61 // knot shapes corresponding to GrPointType enum
  62 SPKnotShapeType gr_knot_shapes [] = {
  63         SP_KNOT_SHAPE_SQUARE, //POINT_LG_BEGIN
  64         SP_KNOT_SHAPE_CIRCLE,  //POINT_LG_END
  65         SP_KNOT_SHAPE_DIAMOND, //POINT_LG_MID
  66         SP_KNOT_SHAPE_SQUARE,  // POINT_RG_CENTER
  67         SP_KNOT_SHAPE_CIRCLE,  // POINT_RG_R1
  68         SP_KNOT_SHAPE_CIRCLE,  // POINT_RG_R2
  69         SP_KNOT_SHAPE_CROSS, // POINT_RG_FOCUS
  70         SP_KNOT_SHAPE_DIAMOND, //POINT_RG_MID1
  71         SP_KNOT_SHAPE_DIAMOND //POINT_RG_MID2
  72 };
  73
  74 const gchar *gr_knot_descr [] = {
  75     N_("Linear gradient <b>start</b>"), //POINT_LG_BEGIN
  76     N_("Linear gradient <b>end</b>"),
  77     N_("Linear gradient <b>mid stop</b>"),
  78     N_("Radial gradient <b>center</b>"),
  79     N_("Radial gradient <b>radius</b>"),
  80     N_("Radial gradient <b>radius</b>"),
  81     N_("Radial gradient <b>focus</b>"), // POINT_RG_FOCUS
  82     N_("Radial gradient <b>mid stop</b>"),
  83     N_("Radial gradient <b>mid stop</b>")
  84 };
  85
  86 static void
  87 gr_drag_sel_changed(Inkscape::Selection */*selection*/, gpointer data)
  88 {
  89     GrDrag *drag = (GrDrag *) data;
  90     drag->updateDraggers ();
  91     drag->updateLines ();
  92     drag->updateLevels ();
  93 }
  94
  95 static void
  96 gr_drag_sel_modified (Inkscape::Selection */*selection*/, guint /*flags*/, gpointer data)
  97 {
  98     GrDrag *drag = (GrDrag *) data;
  99     if (drag->local_change) {
 100         drag->local_change = false;
 101     } else {
 102         drag->updateDraggers ();
 103     }
 104     drag->updateLines ();
 105     drag->updateLevels ();
 106 }
 107
 108 /**
 109 When a _query_style_signal is received, check that \a property requests fill/stroke/opacity (otherwise
 110 skip), and fill the \a style with the averaged color of all draggables of the selected dragger, if
 111 any.
 112 */
 113 int
 114 gr_drag_style_query (SPStyle *style, int property, gpointer data)
 115 {
 116     GrDrag *drag = (GrDrag *) data;
 117
 118     if (property != QUERY_STYLE_PROPERTY_FILL && property != QUERY_STYLE_PROPERTY_STROKE && property != QUERY_STYLE_PROPERTY_MASTEROPACITY) {
 119         return QUERY_STYLE_NOTHING;
 120     }
 121
 122     if (!drag->selected) {
 123         return QUERY_STYLE_NOTHING;
 124     } else {
 125         int ret = QUERY_STYLE_NOTHING;
 126
 127         float cf[4];
 128         cf[0] = cf[1] = cf[2] = cf[3] = 0;
 129
 130         int count = 0;
 131
 132         for (GList *i = drag->selected; i != NULL; i = i->next) { // for all selected draggers
 133             GrDragger *d = (GrDragger *) i->data;
 134             for (GSList const* j = d->draggables; j != NULL; j = j->next) { // for all draggables of dragger
 135                 GrDraggable *draggable = (GrDraggable *) j->data;
 136
 137                 if (ret == QUERY_STYLE_NOTHING) {
 138                     ret = QUERY_STYLE_SINGLE;
 139                 } else if (ret == QUERY_STYLE_SINGLE) {
 140                     ret = QUERY_STYLE_MULTIPLE_AVERAGED;
 141                 }
 142
 143                 guint32 c = sp_item_gradient_stop_query_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 144                 cf[0] += SP_RGBA32_R_F (c);
 145                 cf[1] += SP_RGBA32_G_F (c);
 146                 cf[2] += SP_RGBA32_B_F (c);
 147                 cf[3] += SP_RGBA32_A_F (c);
 148
 149                 count ++;
 150             }
 151         }
 152
 153         if (count) {
 154             cf[0] /= count;
 155             cf[1] /= count;
 156             cf[2] /= count;
 157             cf[3] /= count;
 158
 159             // set both fill and stroke with our stop-color and stop-opacity
 160             style->fill.clear();
 161             style->fill.setColor( cf[0], cf[1], cf[2] );
 162             style->fill.set = TRUE;
 163             style->stroke.clear();
 164             style->stroke.setColor( cf[0], cf[1], cf[2] );
 165             style->stroke.set = TRUE;
 166
 167             style->fill_opacity.value = SP_SCALE24_FROM_FLOAT (1.0);
 168             style->fill_opacity.set = TRUE;
 169             style->stroke_opacity.value = SP_SCALE24_FROM_FLOAT (1.0);
 170             style->stroke_opacity.set = TRUE;
 171
 172             style->opacity.value = SP_SCALE24_FROM_FLOAT (cf[3]);
 173             style->opacity.set = TRUE;
 174         }
 175
 176         return ret;
 177     }
 178 }
 179
 180 bool
 181 gr_drag_style_set (const SPCSSAttr *css, gpointer data)
 182 {
 183     GrDrag *drag = (GrDrag *) data;
 184
 185     if (!drag->selected)
 186         return false;
 187
 188     SPCSSAttr *stop = sp_repr_css_attr_new ();
 189
 190     // See if the css contains interesting properties, and if so, translate them into the format
 191     // acceptable for gradient stops
 192
 193     // any of color properties, in order of increasing priority:
 194     if (css->attribute("flood-color"))
 195         sp_repr_css_set_property (stop, "stop-color", css->attribute("flood-color"));
 196
 197     if (css->attribute("lighting-color"))
 198         sp_repr_css_set_property (stop, "stop-color", css->attribute("lighting-color"));
 199
 200     if (css->attribute("color"))
 201         sp_repr_css_set_property (stop, "stop-color", css->attribute("color"));
 202
 203     if (css->attribute("stroke") && strcmp(css->attribute("stroke"), "none"))
 204         sp_repr_css_set_property (stop, "stop-color", css->attribute("stroke"));
 205
 206     if (css->attribute("fill") && strcmp(css->attribute("fill"), "none"))
 207         sp_repr_css_set_property (stop, "stop-color", css->attribute("fill"));
 208
 209     if (css->attribute("stop-color"))
 210         sp_repr_css_set_property (stop, "stop-color", css->attribute("stop-color"));
 211
 212
 213     if (css->attribute("stop-opacity")) { // direct setting of stop-opacity has priority
 214         sp_repr_css_set_property (stop, "stop-opacity", css->attribute("stop-opacity"));
 215     } else {  // multiply all opacity properties:
 216         gdouble accumulated = 1.0;
 217         accumulated *= sp_svg_read_percentage(css->attribute("flood-opacity"), 1.0);
 218         accumulated *= sp_svg_read_percentage(css->attribute("opacity"), 1.0);
 219         accumulated *= sp_svg_read_percentage(css->attribute("stroke-opacity"), 1.0);
 220         accumulated *= sp_svg_read_percentage(css->attribute("fill-opacity"), 1.0);
 221
 222         Inkscape::CSSOStringStream os;
 223         os << accumulated;
 224         sp_repr_css_set_property (stop, "stop-opacity", os.str().c_str());
 225
 226         if ((css->attribute("fill") && !css->attribute("stroke") && !strcmp(css->attribute("fill"), "none")) ||
 227             (css->attribute("stroke") && !css->attribute("fill") && !strcmp(css->attribute("stroke"), "none")))
 228             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
 229     }
 230
 231     if (!stop->attributeList()) { // nothing for us here, pass it on
 232         sp_repr_css_attr_unref(stop);
 233         return false;
 234     }
 235
 236     for (GList const* sel = drag->selected; sel != NULL; sel = sel->next) { // for all selected draggers
 237         GrDragger* dragger = (GrDragger*) sel->data;
 238         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 239                GrDraggable *draggable = (GrDraggable *) i->data;
 240
 241                drag->local_change = true;
 242                sp_item_gradient_stop_set_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke, stop);
 243         }
 244     }
 245
 246     //sp_repr_css_print(stop);
 247     sp_repr_css_attr_unref(stop);
 248     return true;
 249 }
 250
 251 bool
 252 GrDrag::copy()
 253 {
 254     if (!selected)
 255         return false;
 256
 257     float cf[4];
 258     cf[0] = cf[1] = cf[2] = cf[3] = 0;
 259
 260     int count = 0;
 261
 262     for (GList *i = selected; i != NULL; i = i->next) { // for all selected draggers
 263         GrDragger *d = (GrDragger *) i->data;
 264         for (GSList const* j = d->draggables; j != NULL; j = j->next) { // for all draggables of dragger
 265             GrDraggable *draggable = (GrDraggable *) j->data;
 266
 267             guint32 c = sp_item_gradient_stop_query_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 268             cf[0] += SP_RGBA32_R_F (c);
 269             cf[1] += SP_RGBA32_G_F (c);
 270             cf[2] += SP_RGBA32_B_F (c);
 271             cf[3] += SP_RGBA32_A_F (c);
 272
 273             count ++;
 274         }
 275     }
 276
 277     if (count) {
 278         cf[0] /= count;
 279         cf[1] /= count;
 280         cf[2] /= count;
 281         cf[3] /= count;
 282     }
 283
 284     guint32 const c32 = SP_RGBA32_F_COMPOSE(cf[0], cf[1], cf[2], cf[3]);
 285     gchar c[64];
 286
 287     SPCSSAttr *css = sp_repr_css_attr_new ();
 288     g_snprintf(c, 64, "#%06x", c32 >> 8);
 289     sp_repr_css_set_property (css, "fill", c);
 290     Inkscape::CSSOStringStream os;
 291     os << cf[3];
 292     sp_repr_css_set_property (css, "opacity", os.str().c_str());
 293     sp_set_style_clipboard (css);
 294
 295     g_snprintf(c, 64, "%06x%02x", c32 >> 8, c32 & 0x000000ff);
 296     Glib::ustring text;
 297     text += c;
 298     if (!text.empty())
 299     {
 300         Glib::RefPtr<Gtk::Clipboard> refClipboard =
 301             Gtk::Clipboard::get();
 302         refClipboard->set_text(text);
 303     }
 304
 305     return true;
 306 }
 307
 308 SPStop *
 309 GrDrag::addStopNearPoint (SPItem *item, NR::Point mouse_p, double tolerance)
 310 {
 311     gfloat offset; // type of SPStop.offset = gfloat
 312     SPGradient *gradient;
 313     bool fill_or_stroke = true;
 314     bool r1_knot = false;
 315
 316     bool addknot = false;
 317     do {
 318         gradient = sp_item_gradient (item, fill_or_stroke);
 319         if (SP_IS_LINEARGRADIENT(gradient)) {
 320             NR::Point begin   = sp_item_gradient_get_coords(item, POINT_LG_BEGIN, 0, fill_or_stroke);
 321             NR::Point end     = sp_item_gradient_get_coords(item, POINT_LG_END, 0, fill_or_stroke);
 322
 323             NR::Point nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 324             double dist_screen = NR::L2 (mouse_p - nearest);
 325             if ( dist_screen < tolerance ) {
 326                 // add the knot
 327                 offset = get_offset_between_points(nearest, begin, end);
 328                 addknot = true;
 329                 break; // break out of the while loop: add only one knot
 330             }
 331         } else if (SP_IS_RADIALGRADIENT(gradient)) {
 332             NR::Point begin = sp_item_gradient_get_coords(item, POINT_RG_CENTER, 0, fill_or_stroke);
 333             NR::Point end   = sp_item_gradient_get_coords(item, POINT_RG_R1, 0, fill_or_stroke);
 334             NR::Point nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 335             double dist_screen = NR::L2 (mouse_p - nearest);
 336             if ( dist_screen < tolerance ) {
 337                 offset = get_offset_between_points(nearest, begin, end);
 338                 addknot = true;
 339                 r1_knot = true;
 340                 break; // break out of the while loop: add only one knot
 341             }
 342
 343             end    = sp_item_gradient_get_coords(item, POINT_RG_R2, 0, fill_or_stroke);
 344             nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 345             dist_screen = NR::L2 (mouse_p - nearest);
 346             if ( dist_screen < tolerance ) {
 347                 offset = get_offset_between_points(nearest, begin, end);
 348                 addknot = true;
 349                 r1_knot = false;
 350                 break; // break out of the while loop: add only one knot
 351             }
 352         }
 353         fill_or_stroke = !fill_or_stroke;
 354     } while (!fill_or_stroke && !addknot) ;
 355
 356     if (addknot) {
 357         SPGradient *vector = sp_gradient_get_forked_vector_if_necessary (gradient, false);
 358         SPStop* prev_stop = sp_first_stop(vector);
 359         SPStop* next_stop = sp_next_stop(prev_stop);
 360         guint i = 1;
 361         while ( (next_stop) && (next_stop->offset < offset) ) {
 362             prev_stop = next_stop;
 363             next_stop = sp_next_stop(next_stop);
 364             i++;
 365         }
 366         if (!next_stop) {
 367             // logical error: the endstop should have offset 1 and should always be more than this offset here
 368             return NULL;
 369         }
 370
 371
 372         SPStop *newstop = sp_vector_add_stop (vector, prev_stop, next_stop, offset);
 373         sp_gradient_ensure_vector (gradient);
 374         updateDraggers();
 375
 376         return newstop;
 377     }
 378
 379     return NULL;
 380 }
 381
 382
 383 bool
 384 GrDrag::dropColor(SPItem */*item*/, gchar *c, NR::Point p)
 385 {
 386     // first, see if we can drop onto one of the existing draggers
 387     for (GList *i = draggers; i != NULL; i = i->next) { // for all draggables of dragger
 388         GrDragger *d = (GrDragger *) i->data;
 389
 390         if (NR::L2(p - d->point)*desktop->current_zoom() < 5) {
 391            SPCSSAttr *stop = sp_repr_css_attr_new ();
 392            sp_repr_css_set_property (stop, "stop-color", c);
 393            sp_repr_css_set_property (stop, "stop-opacity", "1");
 394            for (GSList *j = d->draggables; j != NULL; j = j->next) { // for all draggables of dragger
 395                GrDraggable *draggable = (GrDraggable *) j->data;
 396                local_change = true;
 397                sp_item_gradient_stop_set_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke, stop);
 398            }
 399            sp_repr_css_attr_unref(stop);
 400            return true;
 401         }
 402     }
 403
 404     // now see if we're over line and create a new stop
 405     bool over_line = false;
 406     SPCtrlLine *line = NULL;
 407     if (lines) {
 408         for (GSList *l = lines; (l != NULL) && (!over_line); l = l->next) {
 409             line = (SPCtrlLine*) l->data;
 410             NR::Point nearest = snap_vector_midpoint (p, line->s, line->e, 0);
 411             double dist_screen = NR::L2 (p - nearest) * desktop->current_zoom();
 412             if (line->item && dist_screen < 5) {
 413                 SPStop *stop = addStopNearPoint (line->item, p, 5/desktop->current_zoom());
 414                 if (stop) {
 415                     SPCSSAttr *css = sp_repr_css_attr_new ();
 416                     sp_repr_css_set_property (css, "stop-color", c);
 417                     sp_repr_css_set_property (css, "stop-opacity", "1");
 418                     sp_repr_css_change (SP_OBJECT_REPR (stop), css, "style");
 419                     return true;
 420                 }
 421             }
 422         }
 423     }
 424
 425     return false;
 426 }
 427
 428
 429 GrDrag::GrDrag(SPDesktop *desktop) {
 430
 431     this->desktop = desktop;
 432
 433     this->selection = sp_desktop_selection(desktop);
 434
 435     this->draggers = NULL;
 436     this->lines = NULL;
 437     this->selected = NULL;
 438
 439     this->hor_levels.clear();
 440     this->vert_levels.clear();
 441
 442     this->local_change = false;
 443
 444     this->sel_changed_connection = this->selection->connectChanged(
 445         sigc::bind (
 446             sigc::ptr_fun(&gr_drag_sel_changed),
 447             (gpointer)this )
 448
 449         );
 450     this->sel_modified_connection = this->selection->connectModified(
 451         sigc::bind(
 452             sigc::ptr_fun(&gr_drag_sel_modified),
 453             (gpointer)this )
 454         );
 455
 456     this->style_set_connection = this->desktop->connectSetStyle(
 457         sigc::bind(
 458             sigc::ptr_fun(&gr_drag_style_set),
 459             (gpointer)this )
 460         );
 461
 462     this->style_query_connection = this->desktop->connectQueryStyle(
 463         sigc::bind(
 464             sigc::ptr_fun(&gr_drag_style_query),
 465             (gpointer)this )
 466         );
 467
 468     this->updateDraggers ();
 469     this->updateLines ();
 470     this->updateLevels ();
 471
 472     if (desktop->gr_item) {
 473         this->setSelected (getDraggerFor (desktop->gr_item, desktop->gr_point_type, desktop->gr_point_i, desktop->gr_fill_or_stroke));
 474     }
 475 }
 476
 477 GrDrag::~GrDrag()
 478 {
 479     this->sel_changed_connection.disconnect();
 480     this->sel_modified_connection.disconnect();
 481     this->style_set_connection.disconnect();
 482     this->style_query_connection.disconnect();
 483
 484     if (this->selected) {
 485         GrDraggable *draggable = (GrDraggable *)   ((GrDragger*)this->selected->data)->draggables->data;
 486         desktop->gr_item = draggable->item;
 487         desktop->gr_point_type = draggable->point_type;
 488         desktop->gr_point_i = draggable->point_i;
 489         desktop->gr_fill_or_stroke = draggable->fill_or_stroke;
 490     } else {
 491         desktop->gr_item = NULL;
 492         desktop->gr_point_type = 0;
 493         desktop->gr_point_i = 0;
 494         desktop->gr_fill_or_stroke = true;
 495     }
 496
 497     deselect_all();
 498     for (GList *l = this->draggers; l != NULL; l = l->next) {
 499         delete ((GrDragger *) l->data);
 500     }
 501     g_list_free (this->draggers);
 502     this->draggers = NULL;
 503     this->selected = NULL;
 504
 505     for (GSList *l = this->lines; l != NULL; l = l->next) {
 506         gtk_object_destroy( GTK_OBJECT (l->data));
 507     }
 508     g_slist_free (this->lines);
 509     this->lines = NULL;
 510 }
 511
 512 GrDraggable::GrDraggable (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke)
 513 {
 514     this->item = item;
 515     this->point_type = point_type;
 516     this->point_i = point_i;
 517     this->fill_or_stroke = fill_or_stroke;
 518
 519     g_object_ref (G_OBJECT (this->item));
 520 }
 521
 522 GrDraggable::~GrDraggable ()
 523 {
 524     g_object_unref (G_OBJECT (this->item));
 525 }
 526
 527
 528 SPObject *
 529 GrDraggable::getServer ()
 530 {
 531     if (!item)
 532         return NULL;
 533
 534     SPObject *server = NULL;
 535     if (fill_or_stroke)
 536         server = SP_OBJECT_STYLE_FILL_SERVER (item);
 537     else
 538         server = SP_OBJECT_STYLE_STROKE_SERVER (item);
 539
 540     return server;
 541 }
 542
 543 static void
 544 gr_knot_moved_handler(SPKnot *knot, NR::Point const *ppointer, guint state, gpointer data)
 545 {
 546     GrDragger *dragger = (GrDragger *) data;
 547     GrDrag *drag = dragger->parent;
 548
 549     NR::Point p = *ppointer;
 550
 551     // FIXME: take from prefs
 552     double snap_dist = SNAP_DIST / dragger->parent->desktop->current_zoom();
 553
 554     if (state & GDK_SHIFT_MASK) {
 555         // with Shift; unsnap if we carry more than one draggable
 556         if (dragger->draggables && dragger->draggables->next) {
 557             // create a new dragger
 558             GrDragger *dr_new = new GrDragger (dragger->parent, dragger->point, NULL);
 559             dragger->parent->draggers = g_list_prepend (dragger->parent->draggers, dr_new);
 560             // relink to it all but the first draggable in the list
 561             for (GSList const* i = dragger->draggables->next; i != NULL; i = i->next) {
 562                 GrDraggable *draggable = (GrDraggable *) i->data;
 563                 dr_new->addDraggable (draggable);
 564             }
 565             dr_new->updateKnotShape();
 566             g_slist_free (dragger->draggables->next);
 567             dragger->draggables->next = NULL;
 568             dragger->updateKnotShape();
 569             dragger->updateTip();
 570         }
 571     } else if (!(state & GDK_CONTROL_MASK)) {
 572         // without Shift or Ctrl; see if we need to snap to another dragger
 573         for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 574             GrDragger *d_new = (GrDragger *) di->data;
 575             if (dragger->mayMerge(d_new) && NR::L2 (d_new->point - p) < snap_dist) {
 576
 577                 // Merge draggers:
 578                 for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 579                     GrDraggable *draggable = (GrDraggable *) i->data;
 580                     // copy draggable to d_new:
 581                     GrDraggable *da_new = new GrDraggable (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 582                     d_new->addDraggable (da_new);
 583                 }
 584
 585                 // unlink and delete this dragger
 586                 dragger->parent->draggers = g_list_remove (dragger->parent->draggers, dragger);
 587                 delete dragger;
 588
 589                 // update the new merged dragger
 590                 d_new->fireDraggables(true, false, true);
 591                 d_new->parent->updateLines();
 592                 d_new->parent->setSelected (d_new);
 593                 d_new->updateKnotShape ();
 594                 d_new->updateTip ();
 595                 d_new->updateDependencies(true);
 596                 sp_document_done (sp_desktop_document (d_new->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 597                                   _("Merge gradient handles"));
 598                 return;
 599             }
 600         }
 601     }
 602
 603     if (!((state & GDK_SHIFT_MASK) || ((state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK)))) {
 604         // Try snapping to the grid or guides
 605         SnapManager const &m = dragger->parent->desktop->namedview->snap_manager;
 606         Inkscape::SnappedPoint s = m.freeSnap(Inkscape::Snapper::SNAPPOINT_NODE, p, NULL);
 607         if (s.getDistance() < 1e6) {
 608             p = s.getPoint();
 609             sp_knot_moveto (knot, &p);
 610         } else {
 611             // No snapping so far, let's see if we need to snap to any of the levels
 612             for (guint i = 0; i < dragger->parent->hor_levels.size(); i++) {
 613                 if (fabs(p[NR::Y] - dragger->parent->hor_levels[i]) < snap_dist) {
 614                     p[NR::Y] = dragger->parent->hor_levels[i];
 615                     sp_knot_moveto (knot, &p);
 616                 }
 617             }
 618             for (guint i = 0; i < dragger->parent->vert_levels.size(); i++) {
 619                 if (fabs(p[NR::X] - dragger->parent->vert_levels[i]) < snap_dist) {
 620                     p[NR::X] = dragger->parent->vert_levels[i];
 621                     sp_knot_moveto (knot, &p);
 622                 }
 623             }
 624         }
 625     }
 626
 627     if (state & GDK_CONTROL_MASK) {
 628         unsigned snaps = abs(prefs_get_int_attribute("options.rotationsnapsperpi", "value", 12));
 629         /* 0 means no snapping. */
 630
 631         // This list will store snap vectors from all draggables of dragger
 632         GSList *snap_vectors = NULL;
 633
 634         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) {
 635             GrDraggable *draggable = (GrDraggable *) i->data;
 636
 637             NR::Point *dr_snap = NULL;
 638
 639             if (draggable->point_type == POINT_LG_BEGIN || draggable->point_type == POINT_LG_END) {
 640                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 641                     GrDragger *d_new = (GrDragger *) di->data;
 642                     if (d_new == dragger)
 643                         continue;
 644                     if (d_new->isA (draggable->item,
 645                                     draggable->point_type == POINT_LG_BEGIN? POINT_LG_END : POINT_LG_BEGIN,
 646                                     draggable->fill_or_stroke)) {
 647                         // found the other end of the linear gradient;
 648                         if (state & GDK_SHIFT_MASK) {
 649                             // moving linear around center
 650                             NR::Point center = NR::Point (0.5*(d_new->point + dragger->point));
 651                             dr_snap = &center;
 652                         } else {
 653                             // moving linear around the other end
 654                             dr_snap = &d_new->point;
 655                         }
 656                     }
 657                 }
 658             } else if (draggable->point_type == POINT_RG_R1 || draggable->point_type == POINT_RG_R2 || draggable->point_type == POINT_RG_FOCUS) {
 659                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 660                     GrDragger *d_new = (GrDragger *) di->data;
 661                     if (d_new == dragger)
 662                         continue;
 663                     if (d_new->isA (draggable->item,
 664                                     POINT_RG_CENTER,
 665                                     draggable->fill_or_stroke)) {
 666                         // found the center of the radial gradient;
 667                         dr_snap = &(d_new->point);
 668                     }
 669                 }
 670             } else if (draggable->point_type == POINT_RG_CENTER) {
 671                 // radial center snaps to hor/vert relative to its original position
 672                 dr_snap = &(dragger->point_original);
 673             }
 674
 675             NR::Point *snap_vector = NULL;
 676             if (dr_snap) {
 677                 if (state & GDK_MOD1_MASK) {
 678                     // with Alt, snap to the original angle and its perpendiculars
 679                     snap_vector = get_snap_vector (p, *dr_snap, M_PI/2, NR::atan2 (dragger->point_original - *dr_snap));
 680                 } else {
 681                     // with Ctrl, snap to M_PI/snaps
 682                     snap_vector = get_snap_vector (p, *dr_snap, M_PI/snaps, 0);
 683                 }
 684             }
 685             if (snap_vector) {
 686                 snap_vectors = g_slist_prepend (snap_vectors, snap_vector);
 687             }
 688         }
 689
 690         // Move by the smallest of snap vectors:
 691         NR::Point move(9999, 9999);
 692         for (GSList const *i = snap_vectors; i != NULL; i = i->next) {
 693             NR::Point *snap_vector = (NR::Point *) i->data;
 694             if (NR::L2(*snap_vector) < NR::L2(move))
 695                 move = *snap_vector;
 696         }
 697         if (move[NR::X] < 9999) {
 698             p += move;
 699             sp_knot_moveto (knot, &p);
 700         }
 701
 702         g_slist_free(snap_vectors);
 703     }
 704
 705     drag->keep_selection = (bool) g_list_find(drag->selected, dragger);
 706     bool scale_radial = (state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK);
 707
 708     if (drag->keep_selection) {
 709         NR::Point diff = p - dragger->point;
 710         drag->selected_move_nowrite (diff[NR::X], diff[NR::Y], scale_radial);
 711     } else {
 712         dragger->point = p;
 713         dragger->fireDraggables (false, scale_radial);
 714         dragger->updateDependencies(false);
 715     }
 716
 717 }
 718
 719
 720 static void
 721 gr_midpoint_limits(GrDragger *dragger, SPObject *server, NR::Point *begin, NR::Point *end, NR::Point *low_lim, NR::Point *high_lim, GSList **moving)
 722 {
 723
 724     GrDrag *drag = dragger->parent;
 725     // a midpoint dragger can (logically) only contain one GrDraggable
 726     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 727
 728     // get begin and end points between which dragging is allowed:
 729     // the draglimits are between knot(lowest_i - 1) and knot(highest_i + 1)
 730     *moving = g_slist_append(*moving, dragger);
 731
 732     guint lowest_i = draggable->point_i;
 733     guint highest_i = draggable->point_i;
 734     GrDragger *lowest_dragger = dragger;
 735     GrDragger *highest_dragger = dragger;
 736     if (dragger->isSelected()) {
 737         GrDragger* d_add;
 738         while ( true )
 739         {
 740             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 741             if ( d_add && g_list_find(drag->selected, d_add) ) {
 742                 lowest_i = lowest_i - 1;
 743                 *moving = g_slist_prepend(*moving, d_add);
 744                 lowest_dragger = d_add;
 745             } else {
 746                 break;
 747             }
 748         }
 749
 750         while ( true )
 751         {
 752             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 753             if ( d_add && g_list_find(drag->selected, d_add) ) {
 754                 highest_i = highest_i + 1;
 755                 *moving = g_slist_append(*moving, d_add);
 756                 highest_dragger = d_add;
 757             } else {
 758                 break;
 759             }
 760         }
 761     }
 762
 763     if ( SP_IS_LINEARGRADIENT(server) ) {
 764         guint num = SP_LINEARGRADIENT(server)->vector.stops.size();
 765         GrDragger *d_temp;
 766         if (lowest_i == 1) {
 767             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke);
 768         } else {
 769             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, lowest_i - 1, draggable->fill_or_stroke);
 770         }
 771         if (d_temp)
 772             *begin = d_temp->point;
 773
 774         d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, highest_i + 1, draggable->fill_or_stroke);
 775         if (d_temp == NULL) {
 776             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_END, num-1, draggable->fill_or_stroke);
 777         }
 778         if (d_temp)
 779             *end = d_temp->point;
 780     } else if ( SP_IS_RADIALGRADIENT(server) ) {
 781         guint num = SP_RADIALGRADIENT(server)->vector.stops.size();
 782         GrDragger *d_temp;
 783         if (lowest_i == 1) {
 784             d_temp = drag->getDraggerFor (draggable->item, POINT_RG_CENTER, 0, draggable->fill_or_stroke);
 785         } else {
 786             d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 787         }
 788         if (d_temp)
 789             *begin = d_temp->point;
 790
 791         d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 792         if (d_temp == NULL) {
 793             d_temp = drag->getDraggerFor (draggable->item, (draggable->point_type==POINT_RG_MID1) ? POINT_RG_R1 : POINT_RG_R2, num-1, draggable->fill_or_stroke);
 794         }
 795         if (d_temp)
 796             *end = d_temp->point;
 797     }
 798
 799     *low_lim  = dragger->point - (lowest_dragger->point - *begin);
 800     *high_lim = dragger->point - (highest_dragger->point - *end);
 801 }
 802
 803
 804
 805 /**
 806 Called when a midpoint knot is dragged.
 807 */
 808 static void
 809 gr_knot_moved_midpoint_handler(SPKnot */*knot*/, NR::Point const *ppointer, guint state, gpointer data)
 810 {
 811     GrDragger *dragger = (GrDragger *) data;
 812     GrDrag *drag = dragger->parent;
 813     // a midpoint dragger can (logically) only contain one GrDraggable
 814     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 815
 816     // FIXME: take from prefs
 817     double snap_fraction = 0.1;
 818
 819     NR::Point p = *ppointer;
 820     NR::Point begin(0,0), end(0,0);
 821     NR::Point low_lim(0,0), high_lim(0,0);
 822
 823     SPObject *server = draggable->getServer();
 824
 825     GSList *moving = NULL;
 826     gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
 827
 828     if (state & GDK_CONTROL_MASK) {
 829         p = snap_vector_midpoint (p, low_lim, high_lim, snap_fraction);
 830     } else {
 831         p = snap_vector_midpoint (p, low_lim, high_lim, 0);
 832     }
 833     NR::Point displacement = p - dragger->point;
 834
 835     for (GSList const* i = moving; i != NULL; i = i->next) {
 836         GrDragger *drg = (GrDragger*) i->data;
 837         SPKnot *drgknot = drg->knot;
 838         NR::Point this_move = displacement;
 839         if (state & GDK_MOD1_MASK) {
 840             // FIXME: unify all these profiles (here, in nodepath, in tweak) in one place
 841             double alpha = 1.0;
 842             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
 843                 double x = NR::L2(drg->point - dragger->point)/NR::L2(end - dragger->point);
 844                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 845             } else { // drg is on the begin side from dragger
 846                 double x = NR::L2(drg->point - dragger->point)/NR::L2(begin - dragger->point);
 847                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 848             }
 849         }
 850         drg->point += this_move;
 851         sp_knot_moveto (drgknot, & drg->point);
 852         drg->fireDraggables (false);
 853         drg->updateDependencies(false);
 854     }
 855
 856     g_slist_free(moving);
 857
 858     drag->keep_selection = dragger->isSelected();
 859 }
 860
 861
 862
 863 static void
 864 gr_knot_grabbed_handler (SPKnot */*knot*/, unsigned int /*state*/, gpointer data)
 865 {
 866     GrDragger *dragger = (GrDragger *) data;
 867
 868     sp_canvas_force_full_redraw_after_interruptions(dragger->parent->desktop->canvas, 5);
 869 }
 870
 871 /**
 872 Called when the mouse releases a dragger knot; changes gradient writing to repr, updates other draggers if needed
 873 */
 874 static void
 875 gr_knot_ungrabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 876 {
 877     GrDragger *dragger = (GrDragger *) data;
 878
 879     sp_canvas_end_forced_full_redraws(dragger->parent->desktop->canvas);
 880
 881     dragger->point_original = dragger->point = knot->pos;
 882
 883     if ((state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK)) {
 884         dragger->fireDraggables (true, true);
 885     } else {
 886         dragger->fireDraggables (true);
 887     }
 888
 889     for (GList *i = dragger->parent->selected; i != NULL; i = i->next) {
 890         GrDragger *d = (GrDragger *) i->data;
 891         if (d == dragger)
 892             continue;
 893         d->fireDraggables (true);
 894     }
 895
 896     // make this dragger selected
 897     if (!dragger->parent->keep_selection) {
 898         dragger->parent->setSelected (dragger);
 899     }
 900     dragger->parent->keep_selection = false;
 901
 902     dragger->updateDependencies(true);
 903
 904     // we did an undoable action
 905     sp_document_done (sp_desktop_document (dragger->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 906                       _("Move gradient handle"));
 907 }
 908
 909 /**
 910 Called when a dragger knot is clicked; selects the dragger or deletes it depending on the
 911 state of the keyboard keys
 912 */
 913 static void
 914 gr_knot_clicked_handler(SPKnot */*knot*/, guint state, gpointer data)
 915 {
 916     GrDragger *dragger = (GrDragger *) data;
 917     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 918     if (!draggable) return;
 919
 920     if ( (state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK ) ) {
 921     // delete this knot from vector
 922         SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
 923         gradient = sp_gradient_get_vector (gradient, false);
 924         if (gradient->vector.stops.size() > 2) { // 2 is the minimum
 925                 SPStop *stop = NULL;
 926                 switch (draggable->point_type) {  // if we delete first or last stop, move the next/previous to the edge
 927                 case POINT_LG_BEGIN:
 928                 case POINT_RG_CENTER:
 929                     stop = sp_first_stop(gradient);
 930                         {
 931                             SPStop *next = sp_next_stop (stop);
 932                                 if (next) {
 933                                         next->offset = 0;
 934                                         sp_repr_set_css_double (SP_OBJECT_REPR (next), "offset", 0);
 935                                 }
 936                         }
 937                     break;
 938                 case POINT_LG_END:
 939                 case POINT_RG_R1:
 940                 case POINT_RG_R2:
 941                     stop = sp_last_stop(gradient);
 942                     {
 943                             SPStop *prev = sp_prev_stop (stop, gradient);
 944                             if (prev) {
 945                                     prev->offset = 1;
 946                                     sp_repr_set_css_double (SP_OBJECT_REPR (prev), "offset", 1);
 947                             }
 948                         }
 949                     break;
 950                 case POINT_LG_MID:
 951                 case POINT_RG_MID1:
 952                 case POINT_RG_MID2:
 953                     stop = sp_get_stop_i(gradient, draggable->point_i);
 954                     break;
 955                 }
 956
 957                 SP_OBJECT_REPR(gradient)->removeChild(SP_OBJECT_REPR(stop));
 958                 sp_document_done (SP_OBJECT_DOCUMENT (gradient), SP_VERB_CONTEXT_GRADIENT,
 959                                   _("Delete gradient stop"));
 960         }
 961     } else {
 962     // select the dragger
 963         dragger->point_original = dragger->point;
 964
 965         if ( state & GDK_SHIFT_MASK ) {
 966             dragger->parent->setSelected (dragger, true, false);
 967         } else {
 968             dragger->parent->setSelected (dragger);
 969         }
 970     }
 971 }
 972
 973 /**
 974 Called when a dragger knot is doubleclicked; opens gradient editor with the stop from the first draggable
 975 */
 976 static void
 977 gr_knot_doubleclicked_handler (SPKnot */*knot*/, guint /*state*/, gpointer data)
 978 {
 979     GrDragger *dragger = (GrDragger *) data;
 980
 981     dragger->point_original = dragger->point;
 982
 983     if (dragger->draggables == NULL)
 984         return;
 985
 986     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 987     sp_item_gradient_edit_stop (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 988 }
 989
 990 /**
 991 Act upon all draggables of the dragger, setting them to the dragger's point
 992 */
 993 void
 994 GrDragger::fireDraggables (bool write_repr, bool scale_radial, bool merging_focus)
 995 {
 996     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 997         GrDraggable *draggable = (GrDraggable *) i->data;
 998
 999         // set local_change flag so that selection_changed callback does not regenerate draggers
1000         this->parent->local_change = true;
1001
1002         // change gradient, optionally writing to repr; prevent focus from moving if it's snapped
1003         // to the center, unless it's the first update upon merge when we must snap it to the point
1004         if (merging_focus ||
1005             !(draggable->point_type == POINT_RG_FOCUS && this->isA(draggable->item, POINT_RG_CENTER, draggable->point_i, draggable->fill_or_stroke)))
1006         {
1007             sp_item_gradient_set_coords (draggable->item, draggable->point_type, draggable->point_i, this->point, draggable->fill_or_stroke, write_repr, scale_radial);
1008         }
1009     }
1010 }
1011
1012 /**
1013 Checks if the dragger has a draggable with this point_type
1014  */
1015 bool
1016 GrDragger::isA (gint point_type)
1017 {
1018     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1019         GrDraggable *draggable = (GrDraggable *) i->data;
1020         if (draggable->point_type == point_type) {
1021             return true;
1022         }
1023     }
1024     return false;
1025 }
1026
1027 /**
1028 Checks if the dragger has a draggable with this item, point_type + point_i (number), fill_or_stroke
1029  */
1030 bool
1031 GrDragger::isA (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1032 {
1033     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1034         GrDraggable *draggable = (GrDraggable *) i->data;
1035         if ( (draggable->point_type == point_type) && (draggable->point_i == point_i) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
1036             return true;
1037         }
1038     }
1039     return false;
1040 }
1041
1042 /**
1043 Checks if the dragger has a draggable with this item, point_type, fill_or_stroke
1044  */
1045 bool
1046 GrDragger::isA (SPItem *item, gint point_type, bool fill_or_stroke)
1047 {
1048     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1049         GrDraggable *draggable = (GrDraggable *) i->data;
1050         if ( (draggable->point_type == point_type) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
1051             return true;
1052         }
1053     }
1054     return false;
1055 }
1056
1057 bool
1058 GrDraggable::mayMerge (GrDraggable *da2)
1059 {
1060     if ((this->item == da2->item) && (this->fill_or_stroke == da2->fill_or_stroke)) {
1061         // we must not merge the points of the same gradient!
1062         if (!((this->point_type == POINT_RG_FOCUS && da2->point_type == POINT_RG_CENTER) ||
1063               (this->point_type == POINT_RG_CENTER && da2->point_type == POINT_RG_FOCUS))) {
1064             // except that we can snap center and focus together
1065             return false;
1066         }
1067     }
1068     // disable merging of midpoints.
1069     if ( (this->point_type == POINT_LG_MID) || (da2->point_type == POINT_LG_MID)
1070          || (this->point_type == POINT_RG_MID1) || (da2->point_type == POINT_RG_MID1)
1071          || (this->point_type == POINT_RG_MID2) || (da2->point_type == POINT_RG_MID2) )
1072         return false;
1073
1074     return true;
1075 }
1076
1077 bool
1078 GrDragger::mayMerge (GrDragger *other)
1079 {
1080     if (this == other)
1081         return false;
1082
1083     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
1084         GrDraggable *da1 = (GrDraggable *) i->data;
1085         for (GSList const* j = other->draggables; j != NULL; j = j->next) { // for all draggables of other
1086             GrDraggable *da2 = (GrDraggable *) j->data;
1087             if (!da1->mayMerge(da2))
1088                 return false;
1089         }
1090     }
1091     return true;
1092 }
1093
1094 bool
1095 GrDragger::mayMerge (GrDraggable *da2)
1096 {
1097     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
1098         GrDraggable *da1 = (GrDraggable *) i->data;
1099         if (!da1->mayMerge(da2))
1100             return false;
1101     }
1102     return true;
1103 }
1104
1105 /**
1106 Updates the statusbar tip of the dragger knot, based on its draggables
1107  */
1108 void
1109 GrDragger::updateTip ()
1110 {
1111         if (this->knot && this->knot->tip) {
1112                 g_free (this->knot->tip);
1113                 this->knot->tip = NULL;
1114         }
1115
1116     if (g_slist_length (this->draggables) == 1) {
1117         GrDraggable *draggable = (GrDraggable *) this->draggables->data;
1118         char *item_desc = sp_item_description(draggable->item);
1119         switch (draggable->point_type) {
1120             case POINT_LG_MID:
1121             case POINT_RG_MID1:
1122             case POINT_RG_MID2:
1123                 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"),
1124                                                    _(gr_knot_descr[draggable->point_type]),
1125                                                    draggable->point_i,
1126                                                    item_desc,
1127                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
1128                 break;
1129
1130             default:
1131                 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"),
1132                                                    _(gr_knot_descr[draggable->point_type]),
1133                                                    item_desc,
1134                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
1135                 break;
1136         }
1137         g_free(item_desc);
1138     } else if (g_slist_length (draggables) == 2 && isA (POINT_RG_CENTER) && isA (POINT_RG_FOCUS)) {
1139         this->knot->tip = g_strdup_printf (_("Radial gradient <b>center</b> and <b>focus</b>; drag with <b>Shift</b> to separate focus"));
1140     } else {
1141         int length = g_slist_length (this->draggables);
1142         this->knot->tip = g_strdup_printf (ngettext("Gradient point shared by <b>%d</b> gradient; drag with <b>Shift</b> to separate",
1143                                                     "Gradient point shared by <b>%d</b> gradients; drag with <b>Shift</b> to separate",
1144                                                     length),
1145                                            length);
1146     }
1147 }
1148
1149 /**
1150 Adds a draggable to the dragger
1151  */
1152 void
1153 GrDragger::updateKnotShape ()
1154 {
1155     if (!draggables)
1156         return;
1157     GrDraggable *last = (GrDraggable *) g_slist_last(draggables)->data;
1158     g_object_set (G_OBJECT (this->knot->item), "shape", gr_knot_shapes[last->point_type], NULL);
1159 }
1160
1161 /**
1162 Adds a draggable to the dragger
1163  */
1164 void
1165 GrDragger::addDraggable (GrDraggable *draggable)
1166 {
1167     this->draggables = g_slist_prepend (this->draggables, draggable);
1168
1169     this->updateTip();
1170 }
1171
1172
1173 /**
1174 Moves this dragger to the point of the given draggable, acting upon all other draggables
1175  */
1176 void
1177 GrDragger::moveThisToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1178 {
1179     this->point = sp_item_gradient_get_coords (item, point_type, point_i, fill_or_stroke);
1180     this->point_original = this->point;
1181
1182     sp_knot_moveto (this->knot, &(this->point));
1183
1184     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1185         GrDraggable *da = (GrDraggable *) i->data;
1186         if ( (da->item == item) &&
1187              (point_type == -1 || da->point_type == point_type) &&
1188              (point_i == -1 || da->point_i == point_i) &&
1189              (da->fill_or_stroke == fill_or_stroke) ) {
1190             continue;
1191         }
1192         sp_item_gradient_set_coords (da->item, da->point_type, da->point_i, this->point, da->fill_or_stroke, write_repr, false);
1193     }
1194     // FIXME: here we should also call this->updateDependencies(write_repr); to propagate updating, but how to prevent loops?
1195 }
1196
1197
1198 /**
1199 Moves all midstop draggables that depend on this one
1200  */
1201 void
1202 GrDragger::updateMidstopDependencies (GrDraggable *draggable, bool write_repr) {
1203     SPObject *server = draggable->getServer();
1204     if (!server)
1205         return;
1206     guint num = SP_GRADIENT(server)->vector.stops.size();
1207     if (num <= 2) return;
1208
1209     if ( SP_IS_LINEARGRADIENT(server) ) {
1210         for ( guint i = 1; i < num - 1; i++ ) {
1211             this->moveOtherToDraggable (draggable->item, POINT_LG_MID, i, draggable->fill_or_stroke, write_repr);
1212         }
1213     } else  if ( SP_IS_RADIALGRADIENT(server) ) {
1214         for ( guint i = 1; i < num - 1; i++ ) {
1215             this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, i, draggable->fill_or_stroke, write_repr);
1216             this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, i, draggable->fill_or_stroke, write_repr);
1217         }
1218     }
1219 }
1220
1221
1222 /**
1223 Moves all draggables that depend on this one
1224  */
1225 void
1226 GrDragger::updateDependencies (bool write_repr)
1227 {
1228     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1229         GrDraggable *draggable = (GrDraggable *) i->data;
1230         switch (draggable->point_type) {
1231             case POINT_LG_BEGIN:
1232                 {
1233                     // the end point is dependent only when dragging with ctrl+shift
1234                     this->moveOtherToDraggable (draggable->item, POINT_LG_END, -1, draggable->fill_or_stroke, write_repr);
1235
1236                     this->updateMidstopDependencies (draggable, write_repr);
1237                 }
1238                 break;
1239             case POINT_LG_END:
1240                 {
1241                     // the begin point is dependent only when dragging with ctrl+shift
1242                     this->moveOtherToDraggable (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke, write_repr);
1243
1244                     this->updateMidstopDependencies (draggable, write_repr);
1245                 }
1246                 break;
1247             case POINT_LG_MID:
1248                 // no other nodes depend on mid points.
1249                 break;
1250             case POINT_RG_R2:
1251                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1252                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1253                 this->updateMidstopDependencies (draggable, write_repr);
1254                 break;
1255             case POINT_RG_R1:
1256                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1257                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1258                 this->updateMidstopDependencies (draggable, write_repr);
1259                 break;
1260             case POINT_RG_CENTER:
1261                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1262                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1263                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1264                 this->updateMidstopDependencies (draggable, write_repr);
1265                 break;
1266             case POINT_RG_FOCUS:
1267                 // nothing can depend on that
1268                 break;
1269             case POINT_RG_MID1:
1270                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, draggable->point_i, draggable->fill_or_stroke, write_repr);
1271                 break;
1272             case POINT_RG_MID2:
1273                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, draggable->point_i, draggable->fill_or_stroke, write_repr);
1274                 break;
1275             default:
1276                 break;
1277         }
1278     }
1279 }
1280
1281
1282
1283 GrDragger::GrDragger (GrDrag *parent, NR::Point p, GrDraggable *draggable)
1284 {
1285     this->draggables = NULL;
1286
1287     this->parent = parent;
1288
1289     this->point = p;
1290     this->point_original = p;
1291
1292     // create the knot
1293     this->knot = sp_knot_new (parent->desktop, NULL);
1294     this->knot->setMode(SP_KNOT_MODE_XOR);
1295     this->knot->setFill(GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_MOUSEOVER, GR_KNOT_COLOR_MOUSEOVER);
1296     this->knot->setStroke(0x000000ff, 0x000000ff, 0x000000ff);
1297     sp_knot_update_ctrl(this->knot);
1298
1299     // move knot to the given point
1300     sp_knot_set_position (this->knot, &p, SP_KNOT_STATE_NORMAL);
1301     sp_knot_show (this->knot);
1302
1303     // connect knot's signals
1304     if ( (draggable)  // it can be NULL if a node in unsnapped (eg. focus point unsnapped from center)
1305                        // luckily, midstops never snap to other nodes so are never unsnapped...
1306          && ( (draggable->point_type == POINT_LG_MID)
1307               || (draggable->point_type == POINT_RG_MID1)
1308               || (draggable->point_type == POINT_RG_MID2) ) )
1309     {
1310         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_midpoint_handler), this);
1311     } else {
1312         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_handler), this);
1313     }
1314     g_signal_connect (G_OBJECT (this->knot), "clicked", G_CALLBACK (gr_knot_clicked_handler), this);
1315     g_signal_connect (G_OBJECT (this->knot), "doubleclicked", G_CALLBACK (gr_knot_doubleclicked_handler), this);
1316     g_signal_connect (G_OBJECT (this->knot), "grabbed", G_CALLBACK (gr_knot_grabbed_handler), this);
1317     g_signal_connect (G_OBJECT (this->knot), "ungrabbed", G_CALLBACK (gr_knot_ungrabbed_handler), this);
1318
1319     // add the initial draggable
1320     if (draggable)
1321         this->addDraggable (draggable);
1322     updateKnotShape();
1323 }
1324
1325 GrDragger::~GrDragger ()
1326 {
1327     // unselect if it was selected
1328     this->parent->setDeselected(this);
1329
1330     // disconnect signals
1331     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_moved_handler), this);
1332     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_clicked_handler), this);
1333     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_doubleclicked_handler), this);
1334     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_grabbed_handler), this);
1335     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_ungrabbed_handler), this);
1336
1337     /* unref should call destroy */
1338     g_object_unref (G_OBJECT (this->knot));
1339
1340     // delete all draggables
1341     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1342         delete ((GrDraggable *) i->data);
1343     }
1344     g_slist_free (this->draggables);
1345     this->draggables = NULL;
1346 }
1347
1348 /**
1349 Select the dragger which has the given draggable.
1350 */
1351 GrDragger *
1352 GrDrag::getDraggerFor (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1353 {
1354     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1355         GrDragger *dragger = (GrDragger *) i->data;
1356         for (GSList const* j = dragger->draggables; j != NULL; j = j->next) {
1357             GrDraggable *da2 = (GrDraggable *) j->data;
1358             if ( (da2->item == item) &&
1359                  (point_type == -1 || da2->point_type == point_type) && // -1 means this does not matter
1360                  (point_i == -1 || da2->point_i == point_i) && // -1 means this does not matter
1361                  (da2->fill_or_stroke == fill_or_stroke)) {
1362                 return (dragger);
1363             }
1364         }
1365     }
1366     return NULL;
1367 }
1368
1369
1370 void
1371 GrDragger::moveOtherToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1372 {
1373     GrDragger *d = this->parent->getDraggerFor (item, point_type, point_i, fill_or_stroke);
1374     if (d && d !=  this) {
1375         d->moveThisToDraggable (item, point_type, point_i, fill_or_stroke, write_repr);
1376     }
1377 }
1378
1379
1380 /**
1381   Draw this dragger as selected
1382 */
1383 void
1384 GrDragger::select()
1385 {
1386     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_SELECTED;
1387     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_SELECTED, NULL);
1388 }
1389
1390 /**
1391   Draw this dragger as normal (deselected)
1392 */
1393 void
1394 GrDragger::deselect()
1395 {
1396     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_NORMAL;
1397     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_NORMAL, NULL);
1398 }
1399
1400 bool
1401 GrDragger::isSelected()
1402 {
1403     return g_list_find (parent->selected, this);
1404 }
1405
1406 /**
1407 \brief Deselect all stops/draggers (private)
1408 */
1409 void
1410 GrDrag::deselect_all()
1411 {
1412     while (selected) {
1413         ( (GrDragger*) selected->data)->deselect();
1414         selected = g_list_remove(selected, selected->data);
1415     }
1416 }
1417
1418 /**
1419 \brief Deselect all stops/draggers (public; emits signal)
1420 */
1421 void
1422 GrDrag::deselectAll()
1423 {
1424     deselect_all();
1425     this->desktop->emitToolSubselectionChanged(NULL);
1426 }
1427
1428 /**
1429 \brief Select all stops/draggers
1430 */
1431 void
1432 GrDrag::selectAll()
1433 {
1434     for (GList *l = this->draggers; l != NULL; l = l->next) {
1435         GrDragger *d = ((GrDragger *) l->data);
1436         setSelected (d, true, true);
1437     }
1438 }
1439
1440 /**
1441 \brief Select all stops/draggers that match the coords
1442 */
1443 void
1444 GrDrag::selectByCoords(std::vector<NR::Point> coords)
1445 {
1446     for (GList *l = this->draggers; l != NULL; l = l->next) {
1447         GrDragger *d = ((GrDragger *) l->data);
1448         for (guint k = 0; k < coords.size(); k++) {
1449             if (NR::L2 (d->point - coords[k]) < 1e-4) {
1450                 setSelected (d, true, true);
1451             }
1452         }
1453     }
1454 }
1455
1456
1457 /**
1458 \brief Select all stops/draggers that fall within the rect
1459 */
1460 void
1461 GrDrag::selectRect(NR::Rect const &r)
1462 {
1463     for (GList *l = this->draggers; l != NULL; l = l->next) {
1464         GrDragger *d = ((GrDragger *) l->data);
1465         if (r.contains(d->point)) {
1466            setSelected (d, true, true);
1467         }
1468     }
1469 }
1470
1471 /**
1472 \brief Select a dragger
1473 \param dragger       The dragger to select
1474 \param add_to_selection   If true, add to selection, otherwise deselect others
1475 \param override      If true, always select this node, otherwise toggle selected status
1476 */
1477 void
1478 GrDrag::setSelected (GrDragger *dragger, bool add_to_selection, bool override)
1479 {
1480     GrDragger *seldragger = NULL;
1481
1482     if (add_to_selection) {
1483         if (!dragger) return;
1484         if (override) {
1485             if (!g_list_find(selected, dragger)) {
1486                 selected = g_list_prepend(selected, dragger);
1487             }
1488             dragger->select();
1489             seldragger = dragger;
1490         } else { // toggle
1491             if (g_list_find(selected, dragger)) {
1492                 selected = g_list_remove(selected, dragger);
1493                 dragger->deselect();
1494                 if (selected) {
1495                     seldragger = (GrDragger*) selected->data; // select the dragger that is first in the list
1496                 }
1497             } else {
1498                 selected = g_list_prepend(selected, dragger);
1499                 dragger->select();
1500                 seldragger = dragger;
1501             }
1502         }
1503     } else {
1504         deselect_all();
1505         if (dragger) {
1506             selected = g_list_prepend(selected, dragger);
1507             dragger->select();
1508             seldragger = dragger;
1509         }
1510     }
1511     if (seldragger) {
1512         this->desktop->emitToolSubselectionChanged((gpointer) seldragger);
1513     }
1514 }
1515
1516 /**
1517 \brief Deselect a dragger
1518 \param dragger       The dragger to deselect
1519 */
1520 void
1521 GrDrag::setDeselected (GrDragger *dragger)
1522 {
1523     if (g_list_find(selected, dragger)) {
1524         selected = g_list_remove(selected, dragger);
1525         dragger->deselect();
1526     }
1527     this->desktop->emitToolSubselectionChanged((gpointer) (selected ? selected->data : NULL ));
1528 }
1529
1530
1531
1532 /**
1533 Create a line from p1 to p2 and add it to the lines list
1534  */
1535 void
1536 GrDrag::addLine (SPItem *item, NR::Point p1, NR::Point p2, guint32 rgba)
1537 {
1538     SPCanvasItem *line = sp_canvas_item_new(sp_desktop_controls(this->desktop),
1539                                                             SP_TYPE_CTRLLINE, NULL);
1540     SP_CTRLLINE(line)->item = item;
1541     sp_ctrlline_set_coords(SP_CTRLLINE(line), p1, p2);
1542     if (rgba != GR_LINE_COLOR_FILL) // fill is the default, so don't set color for it to speed up redraw
1543         sp_ctrlline_set_rgba32 (SP_CTRLLINE(line), rgba);
1544     sp_canvas_item_show (line);
1545     this->lines = g_slist_append (this->lines, line);
1546 }
1547
1548 /**
1549 If there already exists a dragger within MERGE_DIST of p, add the draggable to it; otherwise create
1550 new dragger and add it to draggers list
1551  */
1552 void
1553 GrDrag::addDragger (GrDraggable *draggable)
1554 {
1555     NR::Point p = sp_item_gradient_get_coords (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
1556
1557     for (GList *i = this->draggers; i != NULL; i = i->next) {
1558         GrDragger *dragger = (GrDragger *) i->data;
1559         if (dragger->mayMerge (draggable) && NR::L2 (dragger->point - p) < MERGE_DIST) {
1560             // distance is small, merge this draggable into dragger, no need to create new dragger
1561             dragger->addDraggable (draggable);
1562             dragger->updateKnotShape();
1563             return;
1564         }
1565     }
1566
1567     GrDragger *new_dragger = new GrDragger(this, p, draggable);
1568     // fixme: draggers should be added AFTER the last one: this way tabbing through them will be from begin to end.
1569     this->draggers = g_list_append (this->draggers, new_dragger);
1570 }
1571
1572 /**
1573 Add draggers for the radial gradient rg on item
1574 */
1575 void
1576 GrDrag::addDraggersRadial (SPRadialGradient *rg, SPItem *item, bool fill_or_stroke)
1577 {
1578     addDragger (new GrDraggable (item, POINT_RG_CENTER, 0, fill_or_stroke));
1579     guint num = rg->vector.stops.size();
1580     if (num > 2) {
1581         for ( guint i = 1; i < num - 1; i++ ) {
1582             addDragger (new GrDraggable (item, POINT_RG_MID1, i, fill_or_stroke));
1583         }
1584     }
1585     addDragger (new GrDraggable (item, POINT_RG_R1, num-1, fill_or_stroke));
1586     if (num > 2) {
1587         for ( guint i = 1; i < num - 1; i++ ) {
1588             addDragger (new GrDraggable (item, POINT_RG_MID2, i, fill_or_stroke));
1589         }
1590     }
1591     addDragger (new GrDraggable (item, POINT_RG_R2, num-1, fill_or_stroke));
1592     addDragger (new GrDraggable (item, POINT_RG_FOCUS, 0, fill_or_stroke));
1593 }
1594
1595 /**
1596 Add draggers for the linear gradient lg on item
1597 */
1598 void
1599 GrDrag::addDraggersLinear (SPLinearGradient *lg, SPItem *item, bool fill_or_stroke)
1600 {
1601     addDragger (new GrDraggable (item, POINT_LG_BEGIN, 0, fill_or_stroke));
1602     guint num = lg->vector.stops.size();
1603     if (num > 2) {
1604         for ( guint i = 1; i < num - 1; i++ ) {
1605             addDragger (new GrDraggable (item, POINT_LG_MID, i, fill_or_stroke));
1606         }
1607     }
1608     addDragger (new GrDraggable (item, POINT_LG_END, num-1, fill_or_stroke));
1609 }
1610
1611 /**
1612 Artificially grab the knot of this dragger; used by the gradient context
1613 */
1614 void
1615 GrDrag::grabKnot (GrDragger *dragger, gint x, gint y, guint32 etime)
1616 {
1617     if (dragger) {
1618         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1619     }
1620 }
1621
1622 /**
1623 Artificially grab the knot of the dragger with this draggable; used by the gradient context
1624 */
1625 void
1626 GrDrag::grabKnot (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, gint x, gint y, guint32 etime)
1627 {
1628     GrDragger *dragger = getDraggerFor (item, point_type, point_i, fill_or_stroke);
1629     if (dragger) {
1630         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1631     }
1632 }
1633
1634 /**
1635 Regenerates the draggers list from the current selection; is called when selection is changed or
1636 modified, also when a radial dragger needs to update positions of other draggers in the gradient
1637 */
1638 void
1639 GrDrag::updateDraggers ()
1640 {
1641     while (selected) {
1642         selected = g_list_remove(selected, selected->data);
1643     }
1644     // delete old draggers
1645     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1646         delete ((GrDragger *) i->data);
1647     }
1648     g_list_free (this->draggers);
1649     this->draggers = NULL;
1650
1651     g_return_if_fail (this->selection != NULL);
1652
1653     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1654
1655         SPItem *item = SP_ITEM(i->data);
1656         SPStyle *style = SP_OBJECT_STYLE (item);
1657
1658         if (style && (style->fill.isPaintserver())) {
1659             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1660             if (SP_IS_LINEARGRADIENT (server)) {
1661                 addDraggersLinear (SP_LINEARGRADIENT (server), item, true);
1662             } else if (SP_IS_RADIALGRADIENT (server)) {
1663                 addDraggersRadial (SP_RADIALGRADIENT (server), item, true);
1664             }
1665         }
1666
1667         if (style && (style->stroke.isPaintserver())) {
1668             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1669             if (SP_IS_LINEARGRADIENT (server)) {
1670                 addDraggersLinear (SP_LINEARGRADIENT (server), item, false);
1671             } else if (SP_IS_RADIALGRADIENT (server)) {
1672                 addDraggersRadial (SP_RADIALGRADIENT (server), item, false);
1673             }
1674         }
1675     }
1676 }
1677
1678 /**
1679 Regenerates the lines list from the current selection; is called on each move of a dragger, so that
1680 lines are always in sync with the actual gradient
1681 */
1682 void
1683 GrDrag::updateLines ()
1684 {
1685     // delete old lines
1686     for (GSList const *i = this->lines; i != NULL; i = i->next) {
1687         gtk_object_destroy( GTK_OBJECT (i->data));
1688     }
1689     g_slist_free (this->lines);
1690     this->lines = NULL;
1691
1692     g_return_if_fail (this->selection != NULL);
1693
1694     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1695
1696         SPItem *item = SP_ITEM(i->data);
1697
1698         SPStyle *style = SP_OBJECT_STYLE (item);
1699
1700         if (style && (style->fill.isPaintserver())) {
1701             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1702             if (SP_IS_LINEARGRADIENT (server)) {
1703                 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);
1704             } else if (SP_IS_RADIALGRADIENT (server)) {
1705                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, true);
1706                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, true), GR_LINE_COLOR_FILL);
1707                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, true), GR_LINE_COLOR_FILL);
1708             }
1709         }
1710
1711         if (style && (style->stroke.isPaintserver())) {
1712             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1713             if (SP_IS_LINEARGRADIENT (server)) {
1714                 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);
1715             } else if (SP_IS_RADIALGRADIENT (server)) {
1716                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, false);
1717                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, false), GR_LINE_COLOR_STROKE);
1718                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, false), GR_LINE_COLOR_STROKE);
1719             }
1720         }
1721     }
1722 }
1723
1724 /**
1725 Regenerates the levels list from the current selection
1726 */
1727 void
1728 GrDrag::updateLevels ()
1729 {
1730     hor_levels.clear();
1731     vert_levels.clear();
1732
1733     g_return_if_fail (this->selection != NULL);
1734
1735     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1736         SPItem *item = SP_ITEM(i->data);
1737         NR::Maybe<NR::Rect> rect = sp_item_bbox_desktop (item);
1738         if (rect) {
1739             // Remember the edges of the bbox and the center axis
1740             hor_levels.push_back(rect->min()[NR::Y]);
1741             hor_levels.push_back(rect->max()[NR::Y]);
1742             hor_levels.push_back(0.5 * (rect->min()[NR::Y] + rect->max()[NR::Y]));
1743             vert_levels.push_back(rect->min()[NR::X]);
1744             vert_levels.push_back(rect->max()[NR::X]);
1745             vert_levels.push_back(0.5 * (rect->min()[NR::X] + rect->max()[NR::X]));
1746         }
1747     }
1748 }
1749
1750 void
1751 GrDrag::selected_reverse_vector ()
1752 {
1753     if (selected == NULL)
1754         return;
1755
1756     for (GSList const* i = ( (GrDragger*) selected->data )->draggables; i != NULL; i = i->next) {
1757         GrDraggable *draggable = (GrDraggable *) i->data;
1758
1759         sp_item_gradient_reverse_vector (draggable->item, draggable->fill_or_stroke);
1760     }
1761 }
1762
1763 void
1764 GrDrag::selected_move_nowrite (double x, double y, bool scale_radial)
1765 {
1766     selected_move (x, y, false, scale_radial);
1767 }
1768
1769 void
1770 GrDrag::selected_move (double x, double y, bool write_repr, bool scale_radial)
1771 {
1772     if (selected == NULL)
1773         return;
1774
1775     bool did = false;
1776
1777     for (GList *i = selected; i != NULL; i = i->next) {
1778         GrDragger *d = (GrDragger *) i->data;
1779
1780         if (!d->isA(POINT_LG_MID) && !d->isA(POINT_RG_MID1) && !d->isA(POINT_RG_MID2)) {
1781             // if this is an endpoint,
1782
1783             // Moving an rg center moves its focus and radii as well.
1784             // therefore, if this is a focus or radius and if selection
1785             // contains the center as well, do not move this one
1786             if (d->isA(POINT_RG_R1) || d->isA(POINT_RG_R2) ||
1787                 (d->isA(POINT_RG_FOCUS) && !d->isA(POINT_RG_CENTER))) {
1788                 bool skip_radius_with_center = false;
1789                 for (GList *di = selected; di != NULL; di = di->next) {
1790                     GrDragger *d_new = (GrDragger *) di->data;
1791                     if (d_new->isA (((GrDraggable *) d->draggables->data)->item,
1792                                     POINT_RG_CENTER,
1793                                     0,
1794                                     ((GrDraggable *) d->draggables->data)->fill_or_stroke)) {
1795                         // FIXME: here we take into account only the first draggable!
1796                         skip_radius_with_center = true;
1797                     }
1798                 }
1799                 if (skip_radius_with_center)
1800                     continue;
1801             }
1802
1803             did = true;
1804             d->point += NR::Point (x, y);
1805             d->point_original = d->point;
1806             sp_knot_moveto (d->knot, &(d->point));
1807
1808             d->fireDraggables (write_repr, scale_radial);
1809
1810             d->updateDependencies(write_repr);
1811         }
1812     }
1813
1814     if (write_repr && did) {
1815         // we did an undoable action
1816         sp_document_maybe_done (sp_desktop_document (desktop), "grmoveh", SP_VERB_CONTEXT_GRADIENT,
1817                                 _("Move gradient handle(s)"));
1818         return;
1819     }
1820
1821     if (!did) { // none of the end draggers are selected, so let's try to move the mids
1822
1823         GrDragger *dragger = (GrDragger *) selected->data;
1824         // a midpoint dragger can (logically) only contain one GrDraggable
1825         GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
1826
1827         NR::Point begin(0,0), end(0,0);
1828         NR::Point low_lim(0,0), high_lim(0,0);
1829
1830         SPObject *server = draggable->getServer();
1831         GSList *moving = NULL;
1832         gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
1833
1834         NR::Point p(x, y);
1835         p = snap_vector_midpoint (dragger->point + p, low_lim, high_lim, 0);
1836         NR::Point displacement = p - dragger->point;
1837
1838         for (GSList const* i = moving; i != NULL; i = i->next) {
1839             GrDragger *drg = (GrDragger*) i->data;
1840             SPKnot *drgknot = drg->knot;
1841             drg->point += displacement;
1842             sp_knot_moveto (drgknot, & drg->point);
1843             drg->fireDraggables (true);
1844             drg->updateDependencies(true);
1845             did = true;
1846         }
1847
1848         g_slist_free(moving);
1849
1850         if (write_repr && did) {
1851             // we did an undoable action
1852             sp_document_maybe_done (sp_desktop_document (desktop), "grmovem", SP_VERB_CONTEXT_GRADIENT,
1853                                     _("Move gradient mid stop(s)"));
1854         }
1855     }
1856 }
1857
1858 void
1859 GrDrag::selected_move_screen (double x, double y)
1860 {
1861     gdouble zoom = desktop->current_zoom();
1862     gdouble zx = x / zoom;
1863     gdouble zy = y / zoom;
1864
1865     selected_move (zx, zy);
1866 }
1867
1868 /**
1869 Select the knot next to the last selected one and deselect all other selected.
1870 */
1871 GrDragger *
1872 GrDrag::select_next ()
1873 {
1874     GrDragger *d = NULL;
1875     if (selected == NULL || g_list_find(draggers, selected->data)->next == NULL) {
1876         if (draggers)
1877             d = (GrDragger *) draggers->data;
1878     } else {
1879         d = (GrDragger *) g_list_find(draggers, selected->data)->next->data;
1880     }
1881     if (d)
1882         setSelected (d);
1883     return d;
1884 }
1885
1886 /**
1887 Select the knot previous from the last selected one and deselect all other selected.
1888 */
1889 GrDragger *
1890 GrDrag::select_prev ()
1891 {
1892     GrDragger *d = NULL;
1893     if (selected == NULL || g_list_find(draggers, selected->data)->prev == NULL) {
1894         if (draggers)
1895             d = (GrDragger *) g_list_last (draggers)->data;
1896     } else {
1897         d = (GrDragger *) g_list_find(draggers, selected->data)->prev->data;
1898     }
1899     if (d)
1900         setSelected (d);
1901     return d;
1902 }
1903
1904
1905 // FIXME: i.m.o. an ugly function that I just made to work, but... aargh! (Johan)
1906 void
1907 GrDrag::deleteSelected (bool just_one)
1908 {
1909     if (!selected) return;
1910
1911     SPDocument *document = false;
1912
1913     struct StructStopInfo {
1914         SPStop * spstop;
1915         GrDraggable * draggable;
1916         SPGradient * gradient;
1917         SPGradient * vector;
1918     };
1919
1920     GSList *midstoplist = NULL;  // list of stops that must be deleted (will be deleted first)
1921     GSList *endstoplist = NULL;  // list of stops that must be deleted
1922     while (selected) {
1923         GrDragger *dragger = (GrDragger*) selected->data;
1924         for (GSList * drgble = dragger->draggables; drgble != NULL; drgble = drgble->next) {
1925             GrDraggable *draggable = (GrDraggable*) drgble->data;
1926             SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
1927             SPGradient *vector   = sp_gradient_get_forked_vector_if_necessary (gradient, false);
1928
1929             switch (draggable->point_type) {
1930                 case POINT_LG_MID:
1931                 case POINT_RG_MID1:
1932                 case POINT_RG_MID2:
1933                     {
1934                         SPStop *stop = sp_get_stop_i(vector, draggable->point_i);
1935                         // check if already present in list. (e.g. when both RG_MID1 and RG_MID2 were selected)
1936                         bool present = false;
1937                         for (GSList const * l = midstoplist; l != NULL; l = l->next) {
1938                             if ( (SPStop*)l->data == stop ) {
1939                                 present = true;
1940                                 break; // no need to search further.
1941                             }
1942                         }
1943                         if (!present)
1944                             midstoplist = g_slist_append(midstoplist, stop);
1945                     }
1946                     break;
1947                 case POINT_LG_BEGIN:
1948                 case POINT_LG_END:
1949                 case POINT_RG_CENTER:
1950                 case POINT_RG_R1:
1951                 case POINT_RG_R2:
1952                     {
1953                         SPStop *stop = NULL;
1954                         if ( (draggable->point_type == POINT_LG_BEGIN) || (draggable->point_type == POINT_RG_CENTER) ) {
1955                             stop = sp_first_stop(vector);
1956                         } else {
1957                             stop = sp_last_stop(vector);
1958                         }
1959                         if (stop) {
1960                             StructStopInfo *stopinfo = new StructStopInfo;
1961                             stopinfo->spstop = stop;
1962                             stopinfo->draggable = draggable;
1963                             stopinfo->gradient = gradient;
1964                             stopinfo->vector = vector;
1965                             // check if already present in list. (e.g. when both R1 and R2 were selected)
1966                             bool present = false;
1967                             for (GSList const * l = endstoplist; l != NULL; l = l->next) {
1968                                 if ( ((StructStopInfo*)l->data)->spstop == stopinfo->spstop ) {
1969                                     present = true;
1970                                     break; // no need to search further.
1971                                 }
1972                             }
1973                             if (!present)
1974                                 endstoplist = g_slist_append(endstoplist, stopinfo);
1975                         }
1976                     }
1977                     break;
1978                 default:
1979                     break;
1980             }
1981         }
1982         selected = g_list_remove(selected, dragger);
1983         if ( just_one ) break; // iterate once if just_one is set.
1984     }
1985     while (midstoplist) {
1986         SPStop *stop = (SPStop*) midstoplist->data;
1987         document = SP_OBJECT_DOCUMENT (stop);
1988         Inkscape::XML::Node * parent = SP_OBJECT_REPR(stop)->parent();
1989         parent->removeChild(SP_OBJECT_REPR(stop));
1990         midstoplist = g_slist_remove(midstoplist, stop);
1991     }
1992     while (endstoplist) {
1993         StructStopInfo *stopinfo  = (StructStopInfo*) endstoplist->data;
1994         document = SP_OBJECT_DOCUMENT (stopinfo->spstop);
1995
1996         // 2 is the minimum, cannot delete more than that without deleting the whole vector
1997         // cannot use vector->vector.stops.size() because the vector might be invalidated by deletion of a midstop
1998         // manually count the children, don't know if there already exists a function for this...
1999         int len = 0;
2000         for ( SPObject *child = sp_object_first_child(stopinfo->vector) ;
2001               child != NULL ;
2002               child = SP_OBJECT_NEXT(child) )
2003         {
2004             if ( SP_IS_STOP(child) )  len ++;
2005         }
2006         if (len > 2)
2007         {
2008             switch (stopinfo->draggable->point_type) {
2009                 case POINT_LG_BEGIN:
2010                     {
2011                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2012
2013                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
2014                         NR::Point oldbegin = NR::Point (lg->x1.computed, lg->y1.computed);
2015                         NR::Point end = NR::Point (lg->x2.computed, lg->y2.computed);
2016                         SPStop *stop = sp_first_stop(stopinfo->vector);
2017                         gdouble offset = stop->offset;
2018                         NR::Point newbegin = oldbegin + offset * (end - oldbegin);
2019                         lg->x1.computed = newbegin[NR::X];
2020                         lg->y1.computed = newbegin[NR::Y];
2021
2022                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
2023                         sp_repr_set_svg_double(repr, "x1", lg->x1.computed);
2024                         sp_repr_set_svg_double(repr, "y1", lg->y1.computed);
2025                         stop->offset = 0;
2026                         sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", 0);
2027
2028                         // iterate through midstops to set new offset values such that they won't move on canvas.
2029                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2030                         stop = sp_next_stop(stop);
2031                         while ( stop != laststop ) {
2032                             stop->offset = (stop->offset - offset)/(1 - offset);
2033                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2034                             stop = sp_next_stop(stop);
2035                         }
2036                     }
2037                     break;
2038                 case POINT_LG_END:
2039                     {
2040                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2041
2042                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
2043                         NR::Point begin = NR::Point (lg->x1.computed, lg->y1.computed);
2044                         NR::Point oldend = NR::Point (lg->x2.computed, lg->y2.computed);
2045                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2046                         gdouble offset = laststop->offset;
2047                         NR::Point newend = begin + offset * (oldend - begin);
2048                         lg->x2.computed = newend[NR::X];
2049                         lg->y2.computed = newend[NR::Y];
2050
2051                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
2052                         sp_repr_set_svg_double(repr, "x2", lg->x2.computed);
2053                         sp_repr_set_svg_double(repr, "y2", lg->y2.computed);
2054                         laststop->offset = 1;
2055                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
2056
2057                         // iterate through midstops to set new offset values such that they won't move on canvas.
2058                         SPStop *stop = sp_first_stop(stopinfo->vector);
2059                         stop = sp_next_stop(stop);
2060                         while ( stop != laststop ) {
2061                             stop->offset = stop->offset / offset;
2062                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2063                             stop = sp_next_stop(stop);
2064                         }
2065                     }
2066                     break;
2067                 case POINT_RG_CENTER:
2068                     {
2069                         SPStop *newfirst = sp_next_stop (stopinfo->spstop);
2070                         if (newfirst) {
2071                             newfirst->offset = 0;
2072                             sp_repr_set_css_double (SP_OBJECT_REPR (newfirst), "offset", 0);
2073                         }
2074                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2075                     }
2076                     break;
2077                 case POINT_RG_R1:
2078                 case POINT_RG_R2:
2079                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2080
2081                         SPRadialGradient *rg = SP_RADIALGRADIENT(stopinfo->gradient);
2082                         double oldradius = rg->r.computed;
2083                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2084                         gdouble offset = laststop->offset;
2085                         double newradius = offset * oldradius;
2086                         rg->r.computed = newradius;
2087
2088                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(rg);
2089                         sp_repr_set_svg_double(repr, "r", rg->r.computed);
2090                         laststop->offset = 1;
2091                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
2092
2093                         // iterate through midstops to set new offset values such that they won't move on canvas.
2094                         SPStop *stop = sp_first_stop(stopinfo->vector);
2095                         stop = sp_next_stop(stop);
2096                         while ( stop != laststop ) {
2097                             stop->offset = stop->offset / offset;
2098                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2099                             stop = sp_next_stop(stop);
2100                         }
2101                         break;
2102             }
2103         }
2104         else
2105         { // delete the gradient from the object. set fill to unset  FIXME: set to fill of unselected node?
2106             SPCSSAttr *css = sp_repr_css_attr_new ();
2107
2108             // stopinfo->spstop is the selected stop
2109             Inkscape::XML::Node *unselectedrepr = SP_OBJECT_REPR(stopinfo->vector)->firstChild();
2110             if (unselectedrepr == SP_OBJECT_REPR(stopinfo->spstop) ) {
2111                 unselectedrepr = unselectedrepr->next();
2112             }
2113
2114             if (unselectedrepr == NULL) {
2115                 if (stopinfo->draggable->fill_or_stroke) {
2116                     sp_repr_css_unset_property (css, "fill");
2117                 } else {
2118                     sp_repr_css_unset_property (css, "stroke");
2119                 }
2120             } else {
2121                 SPCSSAttr *stopcss = sp_repr_css_attr(unselectedrepr, "style");
2122                 if (stopinfo->draggable->fill_or_stroke) {
2123                     sp_repr_css_set_property(css, "fill", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
2124                     sp_repr_css_set_property(css, "fill-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
2125                 } else {
2126                     sp_repr_css_set_property(css, "stroke", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
2127                     sp_repr_css_set_property(css, "stroke-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
2128                 }
2129                 sp_repr_css_attr_unref (stopcss);
2130             }
2131
2132             sp_repr_css_change (SP_OBJECT_REPR (stopinfo->draggable->item), css, "style");
2133             sp_repr_css_attr_unref (css);
2134         }
2135
2136         endstoplist = g_slist_remove(endstoplist, stopinfo);
2137         delete stopinfo;
2138     }
2139
2140     if (document) {
2141         sp_document_done ( document, SP_VERB_CONTEXT_GRADIENT, _("Delete gradient stop(s)") );
2142     }
2143 }
2144
2145
2146 /*
2147   Local Variables:
2148   mode:c++
2149   c-file-style:"stroustrup"
2150   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
2151   indent-tabs-mode:nil
2152   fill-column:99
2153   End:
2154 */
2155 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :