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 "display/sp-canvas-util.h"
  31 #include "xml/repr.h"
  32 #include "svg/css-ostringstream.h"
  33 #include "svg/svg.h"
  34 #include "libnr/nr-point-fns.h"
  35 #include "preferences.h"
  36 #include "sp-item.h"
  37 #include "style.h"
  38 #include "knot.h"
  39 #include "sp-linear-gradient.h"
  40 #include "sp-radial-gradient.h"
  41 #include "gradient-chemistry.h"
  42 #include "gradient-drag.h"
  43 #include "sp-stop.h"
  44 #include "snap.h"
  45 #include "sp-namedview.h"
  46 #include "selection-chemistry.h"
  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 guint32 GrDrag::getColor()
 252 {
 253     if (!selected) return 0;
 254
 255     float cf[4];
 256     cf[0] = cf[1] = cf[2] = cf[3] = 0;
 257
 258     int count = 0;
 259
 260     for (GList *i = selected; i != NULL; i = i->next) { // for all selected draggers
 261         GrDragger *d = (GrDragger *) i->data;
 262         for (GSList const* j = d->draggables; j != NULL; j = j->next) { // for all draggables of dragger
 263             GrDraggable *draggable = (GrDraggable *) j->data;
 264
 265             guint32 c = sp_item_gradient_stop_query_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 266             cf[0] += SP_RGBA32_R_F (c);
 267             cf[1] += SP_RGBA32_G_F (c);
 268             cf[2] += SP_RGBA32_B_F (c);
 269             cf[3] += SP_RGBA32_A_F (c);
 270
 271             count ++;
 272         }
 273     }
 274
 275     if (count) {
 276         cf[0] /= count;
 277         cf[1] /= count;
 278         cf[2] /= count;
 279         cf[3] /= count;
 280     }
 281
 282     return SP_RGBA32_F_COMPOSE(cf[0], cf[1], cf[2], cf[3]);
 283 }
 284
 285 SPStop *
 286 GrDrag::addStopNearPoint (SPItem *item, Geom::Point mouse_p, double tolerance)
 287 {
 288     gfloat offset; // type of SPStop.offset = gfloat
 289     SPGradient *gradient;
 290     bool fill_or_stroke = true;
 291     bool r1_knot = false;
 292
 293     bool addknot = false;
 294     do {
 295         gradient = sp_item_gradient (item, fill_or_stroke);
 296         if (SP_IS_LINEARGRADIENT(gradient)) {
 297             Geom::Point begin   = sp_item_gradient_get_coords(item, POINT_LG_BEGIN, 0, fill_or_stroke);
 298             Geom::Point end     = sp_item_gradient_get_coords(item, POINT_LG_END, 0, fill_or_stroke);
 299
 300             Geom::Point nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 301             double dist_screen = Geom::L2 (mouse_p - nearest);
 302             if ( dist_screen < tolerance ) {
 303                 // add the knot
 304                 offset = get_offset_between_points(nearest, begin, end);
 305                 addknot = true;
 306                 break; // break out of the while loop: add only one knot
 307             }
 308         } else if (SP_IS_RADIALGRADIENT(gradient)) {
 309             Geom::Point begin = sp_item_gradient_get_coords(item, POINT_RG_CENTER, 0, fill_or_stroke);
 310             Geom::Point end   = sp_item_gradient_get_coords(item, POINT_RG_R1, 0, fill_or_stroke);
 311             Geom::Point nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 312             double dist_screen = Geom::L2 (mouse_p - nearest);
 313             if ( dist_screen < tolerance ) {
 314                 offset = get_offset_between_points(nearest, begin, end);
 315                 addknot = true;
 316                 r1_knot = true;
 317                 break; // break out of the while loop: add only one knot
 318             }
 319
 320             end    = sp_item_gradient_get_coords(item, POINT_RG_R2, 0, fill_or_stroke);
 321             nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 322             dist_screen = Geom::L2 (mouse_p - nearest);
 323             if ( dist_screen < tolerance ) {
 324                 offset = get_offset_between_points(nearest, begin, end);
 325                 addknot = true;
 326                 r1_knot = false;
 327                 break; // break out of the while loop: add only one knot
 328             }
 329         }
 330         fill_or_stroke = !fill_or_stroke;
 331     } while (!fill_or_stroke && !addknot) ;
 332
 333     if (addknot) {
 334         SPGradient *vector = sp_gradient_get_forked_vector_if_necessary (gradient, false);
 335         SPStop* prev_stop = sp_first_stop(vector);
 336         SPStop* next_stop = sp_next_stop(prev_stop);
 337         guint i = 1;
 338         while ( (next_stop) && (next_stop->offset < offset) ) {
 339             prev_stop = next_stop;
 340             next_stop = sp_next_stop(next_stop);
 341             i++;
 342         }
 343         if (!next_stop) {
 344             // logical error: the endstop should have offset 1 and should always be more than this offset here
 345             return NULL;
 346         }
 347
 348
 349         SPStop *newstop = sp_vector_add_stop (vector, prev_stop, next_stop, offset);
 350         sp_gradient_ensure_vector (gradient);
 351         updateDraggers();
 352
 353         return newstop;
 354     }
 355
 356     return NULL;
 357 }
 358
 359
 360 bool
 361 GrDrag::dropColor(SPItem */*item*/, gchar *c, Geom::Point p)
 362 {
 363     // first, see if we can drop onto one of the existing draggers
 364     for (GList *i = draggers; i != NULL; i = i->next) { // for all draggables of dragger
 365         GrDragger *d = (GrDragger *) i->data;
 366
 367         if (Geom::L2(p - d->point)*desktop->current_zoom() < 5) {
 368            SPCSSAttr *stop = sp_repr_css_attr_new ();
 369            sp_repr_css_set_property (stop, "stop-color", c);
 370            sp_repr_css_set_property (stop, "stop-opacity", "1");
 371            for (GSList *j = d->draggables; j != NULL; j = j->next) { // for all draggables of dragger
 372                GrDraggable *draggable = (GrDraggable *) j->data;
 373                local_change = true;
 374                sp_item_gradient_stop_set_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke, stop);
 375            }
 376            sp_repr_css_attr_unref(stop);
 377            return true;
 378         }
 379     }
 380
 381     // now see if we're over line and create a new stop
 382     bool over_line = false;
 383     SPCtrlLine *line = NULL;
 384     if (lines) {
 385         for (GSList *l = lines; (l != NULL) && (!over_line); l = l->next) {
 386             line = (SPCtrlLine*) l->data;
 387             Geom::Point nearest = snap_vector_midpoint (p, line->s, line->e, 0);
 388             double dist_screen = Geom::L2 (p - nearest) * desktop->current_zoom();
 389             if (line->item && dist_screen < 5) {
 390                 SPStop *stop = addStopNearPoint (line->item, p, 5/desktop->current_zoom());
 391                 if (stop) {
 392                     SPCSSAttr *css = sp_repr_css_attr_new ();
 393                     sp_repr_css_set_property (css, "stop-color", c);
 394                     sp_repr_css_set_property (css, "stop-opacity", "1");
 395                     sp_repr_css_change (SP_OBJECT_REPR (stop), css, "style");
 396                     return true;
 397                 }
 398             }
 399         }
 400     }
 401
 402     return false;
 403 }
 404
 405
 406 GrDrag::GrDrag(SPDesktop *desktop) {
 407
 408     this->desktop = desktop;
 409
 410     this->selection = sp_desktop_selection(desktop);
 411
 412     this->draggers = NULL;
 413     this->lines = NULL;
 414     this->selected = NULL;
 415
 416     this->hor_levels.clear();
 417     this->vert_levels.clear();
 418
 419     this->local_change = false;
 420
 421     this->sel_changed_connection = this->selection->connectChanged(
 422         sigc::bind (
 423             sigc::ptr_fun(&gr_drag_sel_changed),
 424             (gpointer)this )
 425
 426         );
 427     this->sel_modified_connection = this->selection->connectModified(
 428         sigc::bind(
 429             sigc::ptr_fun(&gr_drag_sel_modified),
 430             (gpointer)this )
 431         );
 432
 433     this->style_set_connection = this->desktop->connectSetStyle(
 434         sigc::bind(
 435             sigc::ptr_fun(&gr_drag_style_set),
 436             (gpointer)this )
 437         );
 438
 439     this->style_query_connection = this->desktop->connectQueryStyle(
 440         sigc::bind(
 441             sigc::ptr_fun(&gr_drag_style_query),
 442             (gpointer)this )
 443         );
 444
 445     this->updateDraggers ();
 446     this->updateLines ();
 447     this->updateLevels ();
 448
 449     if (desktop->gr_item) {
 450         this->setSelected (getDraggerFor (desktop->gr_item, desktop->gr_point_type, desktop->gr_point_i, desktop->gr_fill_or_stroke));
 451     }
 452 }
 453
 454 GrDrag::~GrDrag()
 455 {
 456     this->sel_changed_connection.disconnect();
 457     this->sel_modified_connection.disconnect();
 458     this->style_set_connection.disconnect();
 459     this->style_query_connection.disconnect();
 460
 461     if (this->selected) {
 462         GrDraggable *draggable = (GrDraggable *)   ((GrDragger*)this->selected->data)->draggables->data;
 463         desktop->gr_item = draggable->item;
 464         desktop->gr_point_type = draggable->point_type;
 465         desktop->gr_point_i = draggable->point_i;
 466         desktop->gr_fill_or_stroke = draggable->fill_or_stroke;
 467     } else {
 468         desktop->gr_item = NULL;
 469         desktop->gr_point_type = 0;
 470         desktop->gr_point_i = 0;
 471         desktop->gr_fill_or_stroke = true;
 472     }
 473
 474     deselect_all();
 475     for (GList *l = this->draggers; l != NULL; l = l->next) {
 476         delete ((GrDragger *) l->data);
 477     }
 478     g_list_free (this->draggers);
 479     this->draggers = NULL;
 480     this->selected = NULL;
 481
 482     for (GSList *l = this->lines; l != NULL; l = l->next) {
 483         gtk_object_destroy( GTK_OBJECT (l->data));
 484     }
 485     g_slist_free (this->lines);
 486     this->lines = NULL;
 487 }
 488
 489 GrDraggable::GrDraggable (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke)
 490 {
 491     this->item = item;
 492     this->point_type = point_type;
 493     this->point_i = point_i;
 494     this->fill_or_stroke = fill_or_stroke;
 495
 496     g_object_ref (G_OBJECT (this->item));
 497 }
 498
 499 GrDraggable::~GrDraggable ()
 500 {
 501     g_object_unref (G_OBJECT (this->item));
 502 }
 503
 504
 505 SPObject *
 506 GrDraggable::getServer ()
 507 {
 508     if (!item)
 509         return NULL;
 510
 511     SPObject *server = NULL;
 512     if (fill_or_stroke)
 513         server = SP_OBJECT_STYLE_FILL_SERVER (item);
 514     else
 515         server = SP_OBJECT_STYLE_STROKE_SERVER (item);
 516
 517     return server;
 518 }
 519
 520 static
 521 boost::optional<Geom::Point>
 522 get_snap_vector (Geom::Point p, Geom::Point o, double snap, double initial)
 523 {
 524     double r = L2 (p - o);
 525     if (r < 1e-3) {
 526         return boost::optional<Geom::Point>();
 527     }
 528
 529     double angle = atan2 (p - o);
 530     // snap angle to snaps increments, starting from initial:
 531     double a_snapped = initial + floor((angle - initial)/snap + 0.5) * snap;
 532     // calculate the new position and subtract p to get the vector:
 533     return (o + r * Geom::Point(cos(a_snapped), sin(a_snapped)) - p);
 534 }
 535
 536 static void
 537 gr_knot_moved_handler(SPKnot *knot, Geom::Point const &ppointer, guint state, gpointer data)
 538 {
 539     GrDragger *dragger = (GrDragger *) data;
 540     GrDrag *drag = dragger->parent;
 541
 542     Geom::Point p = ppointer;
 543
 544     // FIXME: take from prefs
 545     double snap_dist = SNAP_DIST / dragger->parent->desktop->current_zoom();
 546
 547     if (state & GDK_SHIFT_MASK) {
 548         // with Shift; unsnap if we carry more than one draggable
 549         if (dragger->draggables && dragger->draggables->next) {
 550             // create a new dragger
 551             GrDragger *dr_new = new GrDragger (dragger->parent, dragger->point, NULL);
 552             dragger->parent->draggers = g_list_prepend (dragger->parent->draggers, dr_new);
 553             // relink to it all but the first draggable in the list
 554             for (GSList const* i = dragger->draggables->next; i != NULL; i = i->next) {
 555                 GrDraggable *draggable = (GrDraggable *) i->data;
 556                 dr_new->addDraggable (draggable);
 557             }
 558             dr_new->updateKnotShape();
 559             g_slist_free (dragger->draggables->next);
 560             dragger->draggables->next = NULL;
 561             dragger->updateKnotShape();
 562             dragger->updateTip();
 563         }
 564     } else if (!(state & GDK_CONTROL_MASK)) {
 565         // without Shift or Ctrl; see if we need to snap to another dragger
 566         for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 567             GrDragger *d_new = (GrDragger *) di->data;
 568             if (dragger->mayMerge(d_new) && Geom::L2 (d_new->point - p) < snap_dist) {
 569
 570                 // Merge draggers:
 571                 for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 572                     GrDraggable *draggable = (GrDraggable *) i->data;
 573                     // copy draggable to d_new:
 574                     GrDraggable *da_new = new GrDraggable (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 575                     d_new->addDraggable (da_new);
 576                 }
 577
 578                 // unlink and delete this dragger
 579                 dragger->parent->draggers = g_list_remove (dragger->parent->draggers, dragger);
 580                 delete dragger;
 581
 582                 // update the new merged dragger
 583                 d_new->fireDraggables(true, false, true);
 584                 d_new->parent->updateLines();
 585                 d_new->parent->setSelected (d_new);
 586                 d_new->updateKnotShape ();
 587                 d_new->updateTip ();
 588                 d_new->updateDependencies(true);
 589                 sp_document_done (sp_desktop_document (d_new->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 590                                   _("Merge gradient handles"));
 591                 return;
 592             }
 593         }
 594     }
 595
 596     if (!((state & GDK_SHIFT_MASK) || ((state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK)))) {
 597         // Try snapping to the grid or guides
 598         SPDesktop *desktop = dragger->parent->desktop;
 599         SnapManager &m = desktop->namedview->snap_manager;
 600         m.setup(desktop);
 601         Inkscape::SnappedPoint s = m.freeSnap(Inkscape::SnapPreferences::SNAPPOINT_NODE, to_2geom(p), Inkscape::SNAPSOURCE_HANDLE);
 602         if (s.getSnapped()) {
 603             p = s.getPoint();
 604             sp_knot_moveto (knot, p);
 605         } else {
 606             bool was_snapped = false;
 607             double dist = NR_HUGE;
 608             // No snapping so far, let's see if we need to snap to any of the levels
 609             for (guint i = 0; i < dragger->parent->hor_levels.size(); i++) {
 610                 dist = fabs(p[Geom::Y] - dragger->parent->hor_levels[i]);
 611                 if (dist < snap_dist) {
 612                     p[Geom::Y] = dragger->parent->hor_levels[i];
 613                     s = Inkscape::SnappedPoint(p, Inkscape::SNAPSOURCE_HANDLE, Inkscape::SNAPTARGET_GRADIENT, dist, snap_dist, false, false);
 614                     was_snapped = true;
 615                     sp_knot_moveto (knot, p);
 616                 }
 617             }
 618             for (guint i = 0; i < dragger->parent->vert_levels.size(); i++) {
 619                 dist = fabs(p[Geom::X] - dragger->parent->vert_levels[i]);
 620                 if (dist < snap_dist) {
 621                     p[Geom::X] = dragger->parent->vert_levels[i];
 622                     s = Inkscape::SnappedPoint(p, Inkscape::SNAPSOURCE_HANDLE, Inkscape::SNAPTARGET_GRADIENT, dist, snap_dist, false, false);
 623                     was_snapped = true;
 624                     sp_knot_moveto (knot, p);
 625                 }
 626             }
 627             if (was_snapped) {
 628                 desktop->snapindicator->set_new_snaptarget(s);
 629             }
 630         }
 631     }
 632
 633     if (state & GDK_CONTROL_MASK) {
 634         Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 635         unsigned snaps = abs(prefs->getInt("/options/rotationsnapsperpi/value", 12));
 636         /* 0 means no snapping. */
 637
 638         // This list will store snap vectors from all draggables of dragger
 639         GSList *snap_vectors = NULL;
 640
 641         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) {
 642             GrDraggable *draggable = (GrDraggable *) i->data;
 643
 644             Geom::Point dr_snap(Geom::infinity(), Geom::infinity());
 645
 646             if (draggable->point_type == POINT_LG_BEGIN || draggable->point_type == POINT_LG_END) {
 647                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 648                     GrDragger *d_new = (GrDragger *) di->data;
 649                     if (d_new == dragger)
 650                         continue;
 651                     if (d_new->isA (draggable->item,
 652                                     draggable->point_type == POINT_LG_BEGIN? POINT_LG_END : POINT_LG_BEGIN,
 653                                     draggable->fill_or_stroke)) {
 654                         // found the other end of the linear gradient;
 655                         if (state & GDK_SHIFT_MASK) {
 656                             // moving linear around center
 657                             Geom::Point center = Geom::Point (0.5*(d_new->point + dragger->point));
 658                             dr_snap = center;
 659                         } else {
 660                             // moving linear around the other end
 661                             dr_snap = d_new->point;
 662                         }
 663                     }
 664                 }
 665             } else if (draggable->point_type == POINT_RG_R1 || draggable->point_type == POINT_RG_R2 || draggable->point_type == POINT_RG_FOCUS) {
 666                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 667                     GrDragger *d_new = (GrDragger *) di->data;
 668                     if (d_new == dragger)
 669                         continue;
 670                     if (d_new->isA (draggable->item,
 671                                     POINT_RG_CENTER,
 672                                     draggable->fill_or_stroke)) {
 673                         // found the center of the radial gradient;
 674                         dr_snap = d_new->point;
 675                     }
 676                 }
 677             } else if (draggable->point_type == POINT_RG_CENTER) {
 678                 // radial center snaps to hor/vert relative to its original position
 679                 dr_snap = dragger->point_original;
 680             }
 681
 682             boost::optional<Geom::Point> snap_vector;
 683             if (dr_snap.isFinite()) {
 684                 if (state & GDK_MOD1_MASK) {
 685                     // with Alt, snap to the original angle and its perpendiculars
 686                     snap_vector = get_snap_vector (p, dr_snap, M_PI/2, Geom::atan2 (dragger->point_original - dr_snap));
 687                 } else {
 688                     // with Ctrl, snap to M_PI/snaps
 689                     snap_vector = get_snap_vector (p, dr_snap, M_PI/snaps, 0);
 690                 }
 691             }
 692             if (snap_vector) {
 693                 snap_vectors = g_slist_prepend (snap_vectors, &(*snap_vector));
 694             }
 695         }
 696
 697         // Move by the smallest of snap vectors:
 698         Geom::Point move(9999, 9999);
 699         for (GSList const *i = snap_vectors; i != NULL; i = i->next) {
 700             Geom::Point *snap_vector = (Geom::Point *) i->data;
 701             if (Geom::L2(*snap_vector) < Geom::L2(move))
 702                 move = *snap_vector;
 703         }
 704         if (move[Geom::X] < 9999) {
 705             p += move;
 706             sp_knot_moveto (knot, p);
 707         }
 708
 709         g_slist_free(snap_vectors);
 710     }
 711
 712     drag->keep_selection = (bool) g_list_find(drag->selected, dragger);
 713     bool scale_radial = (state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK);
 714
 715     if (drag->keep_selection) {
 716         Geom::Point diff = p - dragger->point;
 717         drag->selected_move_nowrite (diff[Geom::X], diff[Geom::Y], scale_radial);
 718     } else {
 719         dragger->point = p;
 720         dragger->fireDraggables (false, scale_radial);
 721         dragger->updateDependencies(false);
 722     }
 723
 724 }
 725
 726
 727 static void
 728 gr_midpoint_limits(GrDragger *dragger, SPObject *server, Geom::Point *begin, Geom::Point *end, Geom::Point *low_lim, Geom::Point *high_lim, GSList **moving)
 729 {
 730
 731     GrDrag *drag = dragger->parent;
 732     // a midpoint dragger can (logically) only contain one GrDraggable
 733     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 734
 735     // get begin and end points between which dragging is allowed:
 736     // the draglimits are between knot(lowest_i - 1) and knot(highest_i + 1)
 737     *moving = g_slist_append(*moving, dragger);
 738
 739     guint lowest_i = draggable->point_i;
 740     guint highest_i = draggable->point_i;
 741     GrDragger *lowest_dragger = dragger;
 742     GrDragger *highest_dragger = dragger;
 743     if (dragger->isSelected()) {
 744         GrDragger* d_add;
 745         while ( true )
 746         {
 747             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 748             if ( d_add && g_list_find(drag->selected, d_add) ) {
 749                 lowest_i = lowest_i - 1;
 750                 *moving = g_slist_prepend(*moving, d_add);
 751                 lowest_dragger = d_add;
 752             } else {
 753                 break;
 754             }
 755         }
 756
 757         while ( true )
 758         {
 759             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 760             if ( d_add && g_list_find(drag->selected, d_add) ) {
 761                 highest_i = highest_i + 1;
 762                 *moving = g_slist_append(*moving, d_add);
 763                 highest_dragger = d_add;
 764             } else {
 765                 break;
 766             }
 767         }
 768     }
 769
 770     if ( SP_IS_LINEARGRADIENT(server) ) {
 771         guint num = SP_LINEARGRADIENT(server)->vector.stops.size();
 772         GrDragger *d_temp;
 773         if (lowest_i == 1) {
 774             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke);
 775         } else {
 776             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, lowest_i - 1, draggable->fill_or_stroke);
 777         }
 778         if (d_temp)
 779             *begin = d_temp->point;
 780
 781         d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, highest_i + 1, draggable->fill_or_stroke);
 782         if (d_temp == NULL) {
 783             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_END, num-1, draggable->fill_or_stroke);
 784         }
 785         if (d_temp)
 786             *end = d_temp->point;
 787     } else if ( SP_IS_RADIALGRADIENT(server) ) {
 788         guint num = SP_RADIALGRADIENT(server)->vector.stops.size();
 789         GrDragger *d_temp;
 790         if (lowest_i == 1) {
 791             d_temp = drag->getDraggerFor (draggable->item, POINT_RG_CENTER, 0, draggable->fill_or_stroke);
 792         } else {
 793             d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 794         }
 795         if (d_temp)
 796             *begin = d_temp->point;
 797
 798         d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 799         if (d_temp == NULL) {
 800             d_temp = drag->getDraggerFor (draggable->item, (draggable->point_type==POINT_RG_MID1) ? POINT_RG_R1 : POINT_RG_R2, num-1, draggable->fill_or_stroke);
 801         }
 802         if (d_temp)
 803             *end = d_temp->point;
 804     }
 805
 806     *low_lim  = dragger->point - (lowest_dragger->point - *begin);
 807     *high_lim = dragger->point - (highest_dragger->point - *end);
 808 }
 809
 810
 811
 812 /**
 813 Called when a midpoint knot is dragged.
 814 */
 815 static void
 816 gr_knot_moved_midpoint_handler(SPKnot */*knot*/, Geom::Point const &ppointer, guint state, gpointer data)
 817 {
 818     GrDragger *dragger = (GrDragger *) data;
 819     GrDrag *drag = dragger->parent;
 820     // a midpoint dragger can (logically) only contain one GrDraggable
 821     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 822
 823     // FIXME: take from prefs
 824     double snap_fraction = 0.1;
 825
 826     Geom::Point p = ppointer;
 827     Geom::Point begin(0,0), end(0,0);
 828     Geom::Point low_lim(0,0), high_lim(0,0);
 829
 830     SPObject *server = draggable->getServer();
 831
 832     GSList *moving = NULL;
 833     gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
 834
 835     if (state & GDK_CONTROL_MASK) {
 836         p = snap_vector_midpoint (p, low_lim, high_lim, snap_fraction);
 837     } else {
 838         p = snap_vector_midpoint (p, low_lim, high_lim, 0);
 839     }
 840     Geom::Point displacement = p - dragger->point;
 841
 842     for (GSList const* i = moving; i != NULL; i = i->next) {
 843         GrDragger *drg = (GrDragger*) i->data;
 844         SPKnot *drgknot = drg->knot;
 845         Geom::Point this_move = displacement;
 846         if (state & GDK_MOD1_MASK) {
 847             // FIXME: unify all these profiles (here, in nodepath, in tweak) in one place
 848             double alpha = 1.0;
 849             if (Geom::L2(drg->point - dragger->point) + Geom::L2(drg->point - begin) - 1e-3 > Geom::L2(dragger->point - begin)) { // drg is on the end side from dragger
 850                 double x = Geom::L2(drg->point - dragger->point)/Geom::L2(end - dragger->point);
 851                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 852             } else { // drg is on the begin side from dragger
 853                 double x = Geom::L2(drg->point - dragger->point)/Geom::L2(begin - dragger->point);
 854                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 855             }
 856         }
 857         drg->point += this_move;
 858         sp_knot_moveto (drgknot, drg->point);
 859         drg->fireDraggables (false);
 860         drg->updateDependencies(false);
 861     }
 862
 863     g_slist_free(moving);
 864
 865     drag->keep_selection = dragger->isSelected();
 866 }
 867
 868
 869
 870 static void
 871 gr_knot_grabbed_handler (SPKnot */*knot*/, unsigned int /*state*/, gpointer data)
 872 {
 873     GrDragger *dragger = (GrDragger *) data;
 874
 875     sp_canvas_force_full_redraw_after_interruptions(dragger->parent->desktop->canvas, 5);
 876 }
 877
 878 /**
 879 Called when the mouse releases a dragger knot; changes gradient writing to repr, updates other draggers if needed
 880 */
 881 static void
 882 gr_knot_ungrabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 883 {
 884     GrDragger *dragger = (GrDragger *) data;
 885
 886     sp_canvas_end_forced_full_redraws(dragger->parent->desktop->canvas);
 887
 888     dragger->point_original = dragger->point = knot->pos;
 889
 890     if ((state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK)) {
 891         dragger->fireDraggables (true, true);
 892     } else {
 893         dragger->fireDraggables (true);
 894     }
 895
 896     for (GList *i = dragger->parent->selected; i != NULL; i = i->next) {
 897         GrDragger *d = (GrDragger *) i->data;
 898         if (d == dragger)
 899             continue;
 900         d->fireDraggables (true);
 901     }
 902
 903     // make this dragger selected
 904     if (!dragger->parent->keep_selection) {
 905         dragger->parent->setSelected (dragger);
 906     }
 907     dragger->parent->keep_selection = false;
 908
 909     dragger->updateDependencies(true);
 910
 911     // we did an undoable action
 912     sp_document_done (sp_desktop_document (dragger->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 913                       _("Move gradient handle"));
 914 }
 915
 916 /**
 917 Called when a dragger knot is clicked; selects the dragger or deletes it depending on the
 918 state of the keyboard keys
 919 */
 920 static void
 921 gr_knot_clicked_handler(SPKnot */*knot*/, guint state, gpointer data)
 922 {
 923     GrDragger *dragger = (GrDragger *) data;
 924     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 925     if (!draggable) return;
 926
 927     if ( (state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK ) ) {
 928     // delete this knot from vector
 929         SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
 930         gradient = sp_gradient_get_vector (gradient, false);
 931         if (gradient->vector.stops.size() > 2) { // 2 is the minimum
 932                 SPStop *stop = NULL;
 933                 switch (draggable->point_type) {  // if we delete first or last stop, move the next/previous to the edge
 934                 case POINT_LG_BEGIN:
 935                 case POINT_RG_CENTER:
 936                     stop = sp_first_stop(gradient);
 937                         {
 938                             SPStop *next = sp_next_stop (stop);
 939                                 if (next) {
 940                                         next->offset = 0;
 941                                         sp_repr_set_css_double (SP_OBJECT_REPR (next), "offset", 0);
 942                                 }
 943                         }
 944                     break;
 945                 case POINT_LG_END:
 946                 case POINT_RG_R1:
 947                 case POINT_RG_R2:
 948                     stop = sp_last_stop(gradient);
 949                     {
 950                             SPStop *prev = sp_prev_stop (stop, gradient);
 951                             if (prev) {
 952                                     prev->offset = 1;
 953                                     sp_repr_set_css_double (SP_OBJECT_REPR (prev), "offset", 1);
 954                             }
 955                         }
 956                     break;
 957                 case POINT_LG_MID:
 958                 case POINT_RG_MID1:
 959                 case POINT_RG_MID2:
 960                     stop = sp_get_stop_i(gradient, draggable->point_i);
 961                     break;
 962                 }
 963
 964                 SP_OBJECT_REPR(gradient)->removeChild(SP_OBJECT_REPR(stop));
 965                 sp_document_done (SP_OBJECT_DOCUMENT (gradient), SP_VERB_CONTEXT_GRADIENT,
 966                                   _("Delete gradient stop"));
 967         }
 968     } else {
 969     // select the dragger
 970         dragger->point_original = dragger->point;
 971
 972         if ( state & GDK_SHIFT_MASK ) {
 973             dragger->parent->setSelected (dragger, true, false);
 974         } else {
 975             dragger->parent->setSelected (dragger);
 976         }
 977     }
 978 }
 979
 980 /**
 981 Called when a dragger knot is doubleclicked; opens gradient editor with the stop from the first draggable
 982 */
 983 static void
 984 gr_knot_doubleclicked_handler (SPKnot */*knot*/, guint /*state*/, gpointer data)
 985 {
 986     GrDragger *dragger = (GrDragger *) data;
 987
 988     dragger->point_original = dragger->point;
 989
 990     if (dragger->draggables == NULL)
 991         return;
 992
 993     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 994     sp_item_gradient_edit_stop (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 995 }
 996
 997 /**
 998 Act upon all draggables of the dragger, setting them to the dragger's point
 999 */
1000 void
1001 GrDragger::fireDraggables (bool write_repr, bool scale_radial, bool merging_focus)
1002 {
1003     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1004         GrDraggable *draggable = (GrDraggable *) i->data;
1005
1006         // set local_change flag so that selection_changed callback does not regenerate draggers
1007         this->parent->local_change = true;
1008
1009         // change gradient, optionally writing to repr; prevent focus from moving if it's snapped
1010         // to the center, unless it's the first update upon merge when we must snap it to the point
1011         if (merging_focus ||
1012             !(draggable->point_type == POINT_RG_FOCUS && this->isA(draggable->item, POINT_RG_CENTER, draggable->point_i, draggable->fill_or_stroke)))
1013         {
1014             sp_item_gradient_set_coords (draggable->item, draggable->point_type, draggable->point_i, this->point, draggable->fill_or_stroke, write_repr, scale_radial);
1015         }
1016     }
1017 }
1018
1019 /**
1020 Checks if the dragger has a draggable with this point_type
1021  */
1022 bool
1023 GrDragger::isA (gint point_type)
1024 {
1025     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1026         GrDraggable *draggable = (GrDraggable *) i->data;
1027         if (draggable->point_type == point_type) {
1028             return true;
1029         }
1030     }
1031     return false;
1032 }
1033
1034 /**
1035 Checks if the dragger has a draggable with this item, point_type + point_i (number), fill_or_stroke
1036  */
1037 bool
1038 GrDragger::isA (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1039 {
1040     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1041         GrDraggable *draggable = (GrDraggable *) i->data;
1042         if ( (draggable->point_type == point_type) && (draggable->point_i == point_i) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
1043             return true;
1044         }
1045     }
1046     return false;
1047 }
1048
1049 /**
1050 Checks if the dragger has a draggable with this item, point_type, fill_or_stroke
1051  */
1052 bool
1053 GrDragger::isA (SPItem *item, gint point_type, bool fill_or_stroke)
1054 {
1055     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1056         GrDraggable *draggable = (GrDraggable *) i->data;
1057         if ( (draggable->point_type == point_type) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
1058             return true;
1059         }
1060     }
1061     return false;
1062 }
1063
1064 bool
1065 GrDraggable::mayMerge (GrDraggable *da2)
1066 {
1067     if ((this->item == da2->item) && (this->fill_or_stroke == da2->fill_or_stroke)) {
1068         // we must not merge the points of the same gradient!
1069         if (!((this->point_type == POINT_RG_FOCUS && da2->point_type == POINT_RG_CENTER) ||
1070               (this->point_type == POINT_RG_CENTER && da2->point_type == POINT_RG_FOCUS))) {
1071             // except that we can snap center and focus together
1072             return false;
1073         }
1074     }
1075     // disable merging of midpoints.
1076     if ( (this->point_type == POINT_LG_MID) || (da2->point_type == POINT_LG_MID)
1077          || (this->point_type == POINT_RG_MID1) || (da2->point_type == POINT_RG_MID1)
1078          || (this->point_type == POINT_RG_MID2) || (da2->point_type == POINT_RG_MID2) )
1079         return false;
1080
1081     return true;
1082 }
1083
1084 bool
1085 GrDragger::mayMerge (GrDragger *other)
1086 {
1087     if (this == other)
1088         return false;
1089
1090     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
1091         GrDraggable *da1 = (GrDraggable *) i->data;
1092         for (GSList const* j = other->draggables; j != NULL; j = j->next) { // for all draggables of other
1093             GrDraggable *da2 = (GrDraggable *) j->data;
1094             if (!da1->mayMerge(da2))
1095                 return false;
1096         }
1097     }
1098     return true;
1099 }
1100
1101 bool
1102 GrDragger::mayMerge (GrDraggable *da2)
1103 {
1104     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
1105         GrDraggable *da1 = (GrDraggable *) i->data;
1106         if (!da1->mayMerge(da2))
1107             return false;
1108     }
1109     return true;
1110 }
1111
1112 /**
1113 Updates the statusbar tip of the dragger knot, based on its draggables
1114  */
1115 void
1116 GrDragger::updateTip ()
1117 {
1118         if (this->knot && this->knot->tip) {
1119                 g_free (this->knot->tip);
1120                 this->knot->tip = NULL;
1121         }
1122
1123     if (g_slist_length (this->draggables) == 1) {
1124         GrDraggable *draggable = (GrDraggable *) this->draggables->data;
1125         char *item_desc = sp_item_description(draggable->item);
1126         switch (draggable->point_type) {
1127             case POINT_LG_MID:
1128             case POINT_RG_MID1:
1129             case POINT_RG_MID2:
1130                 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"),
1131                                                    _(gr_knot_descr[draggable->point_type]),
1132                                                    draggable->point_i,
1133                                                    item_desc,
1134                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
1135                 break;
1136
1137             default:
1138                 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"),
1139                                                    _(gr_knot_descr[draggable->point_type]),
1140                                                    item_desc,
1141                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
1142                 break;
1143         }
1144         g_free(item_desc);
1145     } else if (g_slist_length (draggables) == 2 && isA (POINT_RG_CENTER) && isA (POINT_RG_FOCUS)) {
1146         this->knot->tip = g_strdup_printf (_("Radial gradient <b>center</b> and <b>focus</b>; drag with <b>Shift</b> to separate focus"));
1147     } else {
1148         int length = g_slist_length (this->draggables);
1149         this->knot->tip = g_strdup_printf (ngettext("Gradient point shared by <b>%d</b> gradient; drag with <b>Shift</b> to separate",
1150                                                     "Gradient point shared by <b>%d</b> gradients; drag with <b>Shift</b> to separate",
1151                                                     length),
1152                                            length);
1153     }
1154 }
1155
1156 /**
1157 Adds a draggable to the dragger
1158  */
1159 void
1160 GrDragger::updateKnotShape ()
1161 {
1162     if (!draggables)
1163         return;
1164     GrDraggable *last = (GrDraggable *) g_slist_last(draggables)->data;
1165     g_object_set (G_OBJECT (this->knot->item), "shape", gr_knot_shapes[last->point_type], NULL);
1166 }
1167
1168 /**
1169 Adds a draggable to the dragger
1170  */
1171 void
1172 GrDragger::addDraggable (GrDraggable *draggable)
1173 {
1174     this->draggables = g_slist_prepend (this->draggables, draggable);
1175
1176     this->updateTip();
1177 }
1178
1179
1180 /**
1181 Moves this dragger to the point of the given draggable, acting upon all other draggables
1182  */
1183 void
1184 GrDragger::moveThisToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1185 {
1186     this->point = sp_item_gradient_get_coords (item, point_type, point_i, fill_or_stroke);
1187     this->point_original = this->point;
1188
1189     sp_knot_moveto (this->knot, this->point);
1190
1191     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1192         GrDraggable *da = (GrDraggable *) i->data;
1193         if ( (da->item == item) &&
1194              (point_type == -1 || da->point_type == point_type) &&
1195              (point_i == -1 || da->point_i == point_i) &&
1196              (da->fill_or_stroke == fill_or_stroke) ) {
1197             continue;
1198         }
1199         sp_item_gradient_set_coords (da->item, da->point_type, da->point_i, this->point, da->fill_or_stroke, write_repr, false);
1200     }
1201     // FIXME: here we should also call this->updateDependencies(write_repr); to propagate updating, but how to prevent loops?
1202 }
1203
1204
1205 /**
1206 Moves all midstop draggables that depend on this one
1207  */
1208 void
1209 GrDragger::updateMidstopDependencies (GrDraggable *draggable, bool write_repr) {
1210     SPObject *server = draggable->getServer();
1211     if (!server)
1212         return;
1213     guint num = SP_GRADIENT(server)->vector.stops.size();
1214     if (num <= 2) return;
1215
1216     if ( SP_IS_LINEARGRADIENT(server) ) {
1217         for ( guint i = 1; i < num - 1; i++ ) {
1218             this->moveOtherToDraggable (draggable->item, POINT_LG_MID, i, draggable->fill_or_stroke, write_repr);
1219         }
1220     } else  if ( SP_IS_RADIALGRADIENT(server) ) {
1221         for ( guint i = 1; i < num - 1; i++ ) {
1222             this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, i, draggable->fill_or_stroke, write_repr);
1223             this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, i, draggable->fill_or_stroke, write_repr);
1224         }
1225     }
1226 }
1227
1228
1229 /**
1230 Moves all draggables that depend on this one
1231  */
1232 void
1233 GrDragger::updateDependencies (bool write_repr)
1234 {
1235     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1236         GrDraggable *draggable = (GrDraggable *) i->data;
1237         switch (draggable->point_type) {
1238             case POINT_LG_BEGIN:
1239                 {
1240                     // the end point is dependent only when dragging with ctrl+shift
1241                     this->moveOtherToDraggable (draggable->item, POINT_LG_END, -1, draggable->fill_or_stroke, write_repr);
1242
1243                     this->updateMidstopDependencies (draggable, write_repr);
1244                 }
1245                 break;
1246             case POINT_LG_END:
1247                 {
1248                     // the begin point is dependent only when dragging with ctrl+shift
1249                     this->moveOtherToDraggable (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke, write_repr);
1250
1251                     this->updateMidstopDependencies (draggable, write_repr);
1252                 }
1253                 break;
1254             case POINT_LG_MID:
1255                 // no other nodes depend on mid points.
1256                 break;
1257             case POINT_RG_R2:
1258                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1259                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1260                 this->updateMidstopDependencies (draggable, write_repr);
1261                 break;
1262             case POINT_RG_R1:
1263                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1264                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1265                 this->updateMidstopDependencies (draggable, write_repr);
1266                 break;
1267             case POINT_RG_CENTER:
1268                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
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_FOCUS:
1274                 // nothing can depend on that
1275                 break;
1276             case POINT_RG_MID1:
1277                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, draggable->point_i, draggable->fill_or_stroke, write_repr);
1278                 break;
1279             case POINT_RG_MID2:
1280                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, draggable->point_i, draggable->fill_or_stroke, write_repr);
1281                 break;
1282             default:
1283                 break;
1284         }
1285     }
1286 }
1287
1288
1289
1290 GrDragger::GrDragger (GrDrag *parent, Geom::Point p, GrDraggable *draggable)
1291   : point(p),
1292     point_original(p)
1293 {
1294     this->draggables = NULL;
1295
1296     this->parent = parent;
1297
1298     // create the knot
1299     this->knot = sp_knot_new (parent->desktop, NULL);
1300     this->knot->setMode(SP_KNOT_MODE_XOR);
1301     this->knot->setFill(GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_MOUSEOVER, GR_KNOT_COLOR_MOUSEOVER);
1302     this->knot->setStroke(0x0000007f, 0x0000007f, 0x0000007f);
1303     sp_knot_update_ctrl(this->knot);
1304
1305     // move knot to the given point
1306     sp_knot_set_position (this->knot, p, SP_KNOT_STATE_NORMAL);
1307     sp_knot_show (this->knot);
1308
1309     // connect knot's signals
1310     if ( (draggable)  // it can be NULL if a node in unsnapped (eg. focus point unsnapped from center)
1311                        // luckily, midstops never snap to other nodes so are never unsnapped...
1312          && ( (draggable->point_type == POINT_LG_MID)
1313               || (draggable->point_type == POINT_RG_MID1)
1314               || (draggable->point_type == POINT_RG_MID2) ) )
1315     {
1316         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_midpoint_handler), this);
1317     } else {
1318         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_handler), this);
1319     }
1320     g_signal_connect (G_OBJECT (this->knot), "clicked", G_CALLBACK (gr_knot_clicked_handler), this);
1321     g_signal_connect (G_OBJECT (this->knot), "doubleclicked", G_CALLBACK (gr_knot_doubleclicked_handler), this);
1322     g_signal_connect (G_OBJECT (this->knot), "grabbed", G_CALLBACK (gr_knot_grabbed_handler), this);
1323     g_signal_connect (G_OBJECT (this->knot), "ungrabbed", G_CALLBACK (gr_knot_ungrabbed_handler), this);
1324
1325     // add the initial draggable
1326     if (draggable)
1327         this->addDraggable (draggable);
1328     updateKnotShape();
1329 }
1330
1331 GrDragger::~GrDragger ()
1332 {
1333     // unselect if it was selected
1334     this->parent->setDeselected(this);
1335
1336     // disconnect signals
1337     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_moved_handler), this);
1338     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_clicked_handler), this);
1339     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_doubleclicked_handler), this);
1340     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_grabbed_handler), this);
1341     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_ungrabbed_handler), this);
1342
1343     /* unref should call destroy */
1344     g_object_unref (G_OBJECT (this->knot));
1345
1346     // delete all draggables
1347     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1348         delete ((GrDraggable *) i->data);
1349     }
1350     g_slist_free (this->draggables);
1351     this->draggables = NULL;
1352 }
1353
1354 /**
1355 Select the dragger which has the given draggable.
1356 */
1357 GrDragger *
1358 GrDrag::getDraggerFor (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1359 {
1360     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1361         GrDragger *dragger = (GrDragger *) i->data;
1362         for (GSList const* j = dragger->draggables; j != NULL; j = j->next) {
1363             GrDraggable *da2 = (GrDraggable *) j->data;
1364             if ( (da2->item == item) &&
1365                  (point_type == -1 || da2->point_type == point_type) && // -1 means this does not matter
1366                  (point_i == -1 || da2->point_i == point_i) && // -1 means this does not matter
1367                  (da2->fill_or_stroke == fill_or_stroke)) {
1368                 return (dragger);
1369             }
1370         }
1371     }
1372     return NULL;
1373 }
1374
1375
1376 void
1377 GrDragger::moveOtherToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1378 {
1379     GrDragger *d = this->parent->getDraggerFor (item, point_type, point_i, fill_or_stroke);
1380     if (d && d !=  this) {
1381         d->moveThisToDraggable (item, point_type, point_i, fill_or_stroke, write_repr);
1382     }
1383 }
1384
1385
1386 /**
1387   Draw this dragger as selected
1388 */
1389 void
1390 GrDragger::select()
1391 {
1392     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_SELECTED;
1393     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_SELECTED, NULL);
1394 }
1395
1396 /**
1397   Draw this dragger as normal (deselected)
1398 */
1399 void
1400 GrDragger::deselect()
1401 {
1402     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_NORMAL;
1403     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_NORMAL, NULL);
1404 }
1405
1406 bool
1407 GrDragger::isSelected()
1408 {
1409     return g_list_find (parent->selected, this);
1410 }
1411
1412 /**
1413 \brief Deselect all stops/draggers (private)
1414 */
1415 void
1416 GrDrag::deselect_all()
1417 {
1418     while (selected) {
1419         ( (GrDragger*) selected->data)->deselect();
1420         selected = g_list_remove(selected, selected->data);
1421     }
1422 }
1423
1424 /**
1425 \brief Deselect all stops/draggers (public; emits signal)
1426 */
1427 void
1428 GrDrag::deselectAll()
1429 {
1430     deselect_all();
1431     this->desktop->emitToolSubselectionChanged(NULL);
1432 }
1433
1434 /**
1435 \brief Select all stops/draggers
1436 */
1437 void
1438 GrDrag::selectAll()
1439 {
1440     for (GList *l = this->draggers; l != NULL; l = l->next) {
1441         GrDragger *d = ((GrDragger *) l->data);
1442         setSelected (d, true, true);
1443     }
1444 }
1445
1446 /**
1447 \brief Select all stops/draggers that match the coords
1448 */
1449 void
1450 GrDrag::selectByCoords(std::vector<Geom::Point> coords)
1451 {
1452     for (GList *l = this->draggers; l != NULL; l = l->next) {
1453         GrDragger *d = ((GrDragger *) l->data);
1454         for (guint k = 0; k < coords.size(); k++) {
1455             if (Geom::L2 (d->point - coords[k]) < 1e-4) {
1456                 setSelected (d, true, true);
1457             }
1458         }
1459     }
1460 }
1461
1462
1463 /**
1464 \brief Select all stops/draggers that fall within the rect
1465 */
1466 void
1467 GrDrag::selectRect(Geom::Rect const &r)
1468 {
1469     for (GList *l = this->draggers; l != NULL; l = l->next) {
1470         GrDragger *d = ((GrDragger *) l->data);
1471         if (r.contains(d->point)) {
1472            setSelected (d, true, true);
1473         }
1474     }
1475 }
1476
1477 /**
1478 \brief Select a dragger
1479 \param dragger       The dragger to select
1480 \param add_to_selection   If true, add to selection, otherwise deselect others
1481 \param override      If true, always select this node, otherwise toggle selected status
1482 */
1483 void
1484 GrDrag::setSelected (GrDragger *dragger, bool add_to_selection, bool override)
1485 {
1486     GrDragger *seldragger = NULL;
1487
1488     if (add_to_selection) {
1489         if (!dragger) return;
1490         if (override) {
1491             if (!g_list_find(selected, dragger)) {
1492                 selected = g_list_prepend(selected, dragger);
1493             }
1494             dragger->select();
1495             seldragger = dragger;
1496         } else { // toggle
1497             if (g_list_find(selected, dragger)) {
1498                 selected = g_list_remove(selected, dragger);
1499                 dragger->deselect();
1500                 if (selected) {
1501                     seldragger = (GrDragger*) selected->data; // select the dragger that is first in the list
1502                 }
1503             } else {
1504                 selected = g_list_prepend(selected, dragger);
1505                 dragger->select();
1506                 seldragger = dragger;
1507             }
1508         }
1509     } else {
1510         deselect_all();
1511         if (dragger) {
1512             selected = g_list_prepend(selected, dragger);
1513             dragger->select();
1514             seldragger = dragger;
1515         }
1516     }
1517     if (seldragger) {
1518         this->desktop->emitToolSubselectionChanged((gpointer) seldragger);
1519     }
1520 }
1521
1522 /**
1523 \brief Deselect a dragger
1524 \param dragger       The dragger to deselect
1525 */
1526 void
1527 GrDrag::setDeselected (GrDragger *dragger)
1528 {
1529     if (g_list_find(selected, dragger)) {
1530         selected = g_list_remove(selected, dragger);
1531         dragger->deselect();
1532     }
1533     this->desktop->emitToolSubselectionChanged((gpointer) (selected ? selected->data : NULL ));
1534 }
1535
1536
1537
1538 /**
1539 Create a line from p1 to p2 and add it to the lines list
1540  */
1541 void
1542 GrDrag::addLine (SPItem *item, Geom::Point p1, Geom::Point p2, guint32 rgba)
1543 {
1544     SPCanvasItem *line = sp_canvas_item_new(sp_desktop_controls(this->desktop),
1545                                                             SP_TYPE_CTRLLINE, NULL);
1546     sp_canvas_item_move_to_z(line, 0);
1547     SP_CTRLLINE(line)->item = item;
1548     sp_ctrlline_set_coords(SP_CTRLLINE(line), p1, p2);
1549     if (rgba != GR_LINE_COLOR_FILL) // fill is the default, so don't set color for it to speed up redraw
1550         sp_ctrlline_set_rgba32 (SP_CTRLLINE(line), rgba);
1551     sp_canvas_item_show (line);
1552     this->lines = g_slist_append (this->lines, line);
1553 }
1554
1555 /**
1556 If there already exists a dragger within MERGE_DIST of p, add the draggable to it; otherwise create
1557 new dragger and add it to draggers list
1558  */
1559 void
1560 GrDrag::addDragger (GrDraggable *draggable)
1561 {
1562     Geom::Point p = sp_item_gradient_get_coords (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
1563
1564     for (GList *i = this->draggers; i != NULL; i = i->next) {
1565         GrDragger *dragger = (GrDragger *) i->data;
1566         if (dragger->mayMerge (draggable) && Geom::L2 (dragger->point - p) < MERGE_DIST) {
1567             // distance is small, merge this draggable into dragger, no need to create new dragger
1568             dragger->addDraggable (draggable);
1569             dragger->updateKnotShape();
1570             return;
1571         }
1572     }
1573
1574     GrDragger *new_dragger = new GrDragger(this, p, draggable);
1575     // fixme: draggers should be added AFTER the last one: this way tabbing through them will be from begin to end.
1576     this->draggers = g_list_append (this->draggers, new_dragger);
1577 }
1578
1579 /**
1580 Add draggers for the radial gradient rg on item
1581 */
1582 void
1583 GrDrag::addDraggersRadial (SPRadialGradient *rg, SPItem *item, bool fill_or_stroke)
1584 {
1585     addDragger (new GrDraggable (item, POINT_RG_CENTER, 0, fill_or_stroke));
1586     guint num = rg->vector.stops.size();
1587     if (num > 2) {
1588         for ( guint i = 1; i < num - 1; i++ ) {
1589             addDragger (new GrDraggable (item, POINT_RG_MID1, i, fill_or_stroke));
1590         }
1591     }
1592     addDragger (new GrDraggable (item, POINT_RG_R1, num-1, fill_or_stroke));
1593     if (num > 2) {
1594         for ( guint i = 1; i < num - 1; i++ ) {
1595             addDragger (new GrDraggable (item, POINT_RG_MID2, i, fill_or_stroke));
1596         }
1597     }
1598     addDragger (new GrDraggable (item, POINT_RG_R2, num-1, fill_or_stroke));
1599     addDragger (new GrDraggable (item, POINT_RG_FOCUS, 0, fill_or_stroke));
1600 }
1601
1602 /**
1603 Add draggers for the linear gradient lg on item
1604 */
1605 void
1606 GrDrag::addDraggersLinear (SPLinearGradient *lg, SPItem *item, bool fill_or_stroke)
1607 {
1608     addDragger (new GrDraggable (item, POINT_LG_BEGIN, 0, fill_or_stroke));
1609     guint num = lg->vector.stops.size();
1610     if (num > 2) {
1611         for ( guint i = 1; i < num - 1; i++ ) {
1612             addDragger (new GrDraggable (item, POINT_LG_MID, i, fill_or_stroke));
1613         }
1614     }
1615     addDragger (new GrDraggable (item, POINT_LG_END, num-1, fill_or_stroke));
1616 }
1617
1618 /**
1619 Artificially grab the knot of this dragger; used by the gradient context
1620 */
1621 void
1622 GrDrag::grabKnot (GrDragger *dragger, gint x, gint y, guint32 etime)
1623 {
1624     if (dragger) {
1625         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1626     }
1627 }
1628
1629 /**
1630 Artificially grab the knot of the dragger with this draggable; used by the gradient context
1631 */
1632 void
1633 GrDrag::grabKnot (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, gint x, gint y, guint32 etime)
1634 {
1635     GrDragger *dragger = getDraggerFor (item, point_type, point_i, fill_or_stroke);
1636     if (dragger) {
1637         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1638     }
1639 }
1640
1641 /**
1642 Regenerates the draggers list from the current selection; is called when selection is changed or
1643 modified, also when a radial dragger needs to update positions of other draggers in the gradient
1644 */
1645 void
1646 GrDrag::updateDraggers ()
1647 {
1648     while (selected) {
1649         selected = g_list_remove(selected, selected->data);
1650     }
1651     // delete old draggers
1652     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1653         delete ((GrDragger *) i->data);
1654     }
1655     g_list_free (this->draggers);
1656     this->draggers = NULL;
1657
1658     g_return_if_fail (this->selection != NULL);
1659
1660     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1661
1662         SPItem *item = SP_ITEM(i->data);
1663         SPStyle *style = SP_OBJECT_STYLE (item);
1664
1665         if (style && (style->fill.isPaintserver())) {
1666             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1667             if (SP_IS_LINEARGRADIENT (server)) {
1668                 addDraggersLinear (SP_LINEARGRADIENT (server), item, true);
1669             } else if (SP_IS_RADIALGRADIENT (server)) {
1670                 addDraggersRadial (SP_RADIALGRADIENT (server), item, true);
1671             }
1672         }
1673
1674         if (style && (style->stroke.isPaintserver())) {
1675             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1676             if (SP_IS_LINEARGRADIENT (server)) {
1677                 addDraggersLinear (SP_LINEARGRADIENT (server), item, false);
1678             } else if (SP_IS_RADIALGRADIENT (server)) {
1679                 addDraggersRadial (SP_RADIALGRADIENT (server), item, false);
1680             }
1681         }
1682     }
1683 }
1684
1685 /**
1686 Regenerates the lines list from the current selection; is called on each move of a dragger, so that
1687 lines are always in sync with the actual gradient
1688 */
1689 void
1690 GrDrag::updateLines ()
1691 {
1692     // delete old lines
1693     for (GSList const *i = this->lines; i != NULL; i = i->next) {
1694         gtk_object_destroy( GTK_OBJECT (i->data));
1695     }
1696     g_slist_free (this->lines);
1697     this->lines = NULL;
1698
1699     g_return_if_fail (this->selection != NULL);
1700
1701     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1702
1703         SPItem *item = SP_ITEM(i->data);
1704
1705         SPStyle *style = SP_OBJECT_STYLE (item);
1706
1707         if (style && (style->fill.isPaintserver())) {
1708             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1709             if (SP_IS_LINEARGRADIENT (server)) {
1710                 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);
1711             } else if (SP_IS_RADIALGRADIENT (server)) {
1712                 Geom::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, true);
1713                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, true), GR_LINE_COLOR_FILL);
1714                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, true), GR_LINE_COLOR_FILL);
1715             }
1716         }
1717
1718         if (style && (style->stroke.isPaintserver())) {
1719             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1720             if (SP_IS_LINEARGRADIENT (server)) {
1721                 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);
1722             } else if (SP_IS_RADIALGRADIENT (server)) {
1723                 Geom::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, false);
1724                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, false), GR_LINE_COLOR_STROKE);
1725                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, false), GR_LINE_COLOR_STROKE);
1726             }
1727         }
1728     }
1729 }
1730
1731 /**
1732 Regenerates the levels list from the current selection
1733 */
1734 void
1735 GrDrag::updateLevels ()
1736 {
1737     hor_levels.clear();
1738     vert_levels.clear();
1739
1740     g_return_if_fail (this->selection != NULL);
1741
1742     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1743         SPItem *item = SP_ITEM(i->data);
1744         Geom::OptRect rect = sp_item_bbox_desktop (item);
1745         if (rect) {
1746             // Remember the edges of the bbox and the center axis
1747             hor_levels.push_back(rect->min()[Geom::Y]);
1748             hor_levels.push_back(rect->max()[Geom::Y]);
1749             hor_levels.push_back(0.5 * (rect->min()[Geom::Y] + rect->max()[Geom::Y]));
1750             vert_levels.push_back(rect->min()[Geom::X]);
1751             vert_levels.push_back(rect->max()[Geom::X]);
1752             vert_levels.push_back(0.5 * (rect->min()[Geom::X] + rect->max()[Geom::X]));
1753         }
1754     }
1755 }
1756
1757 void
1758 GrDrag::selected_reverse_vector ()
1759 {
1760     if (selected == NULL)
1761         return;
1762
1763     for (GSList const* i = ( (GrDragger*) selected->data )->draggables; i != NULL; i = i->next) {
1764         GrDraggable *draggable = (GrDraggable *) i->data;
1765
1766         sp_item_gradient_reverse_vector (draggable->item, draggable->fill_or_stroke);
1767     }
1768 }
1769
1770 void
1771 GrDrag::selected_move_nowrite (double x, double y, bool scale_radial)
1772 {
1773     selected_move (x, y, false, scale_radial);
1774 }
1775
1776 void
1777 GrDrag::selected_move (double x, double y, bool write_repr, bool scale_radial)
1778 {
1779     if (selected == NULL)
1780         return;
1781
1782     bool did = false;
1783
1784     for (GList *i = selected; i != NULL; i = i->next) {
1785         GrDragger *d = (GrDragger *) i->data;
1786
1787         if (!d->isA(POINT_LG_MID) && !d->isA(POINT_RG_MID1) && !d->isA(POINT_RG_MID2)) {
1788             // if this is an endpoint,
1789
1790             // Moving an rg center moves its focus and radii as well.
1791             // therefore, if this is a focus or radius and if selection
1792             // contains the center as well, do not move this one
1793             if (d->isA(POINT_RG_R1) || d->isA(POINT_RG_R2) ||
1794                 (d->isA(POINT_RG_FOCUS) && !d->isA(POINT_RG_CENTER))) {
1795                 bool skip_radius_with_center = false;
1796                 for (GList *di = selected; di != NULL; di = di->next) {
1797                     GrDragger *d_new = (GrDragger *) di->data;
1798                     if (d_new->isA (((GrDraggable *) d->draggables->data)->item,
1799                                     POINT_RG_CENTER,
1800                                     0,
1801                                     ((GrDraggable *) d->draggables->data)->fill_or_stroke)) {
1802                         // FIXME: here we take into account only the first draggable!
1803                         skip_radius_with_center = true;
1804                     }
1805                 }
1806                 if (skip_radius_with_center)
1807                     continue;
1808             }
1809
1810             did = true;
1811             d->point += Geom::Point (x, y);
1812             d->point_original = d->point;
1813             sp_knot_moveto (d->knot, d->point);
1814
1815             d->fireDraggables (write_repr, scale_radial);
1816
1817             d->updateDependencies(write_repr);
1818         }
1819     }
1820
1821     if (write_repr && did) {
1822         // we did an undoable action
1823         sp_document_maybe_done (sp_desktop_document (desktop), "grmoveh", SP_VERB_CONTEXT_GRADIENT,
1824                                 _("Move gradient handle(s)"));
1825         return;
1826     }
1827
1828     if (!did) { // none of the end draggers are selected, so let's try to move the mids
1829
1830         GrDragger *dragger = (GrDragger *) selected->data;
1831         // a midpoint dragger can (logically) only contain one GrDraggable
1832         GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
1833
1834         Geom::Point begin(0,0), end(0,0);
1835         Geom::Point low_lim(0,0), high_lim(0,0);
1836
1837         SPObject *server = draggable->getServer();
1838         GSList *moving = NULL;
1839         gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
1840
1841         Geom::Point p(x, y);
1842         p = snap_vector_midpoint (dragger->point + p, low_lim, high_lim, 0);
1843         Geom::Point displacement = p - dragger->point;
1844
1845         for (GSList const* i = moving; i != NULL; i = i->next) {
1846             GrDragger *drg = (GrDragger*) i->data;
1847             SPKnot *drgknot = drg->knot;
1848             drg->point += displacement;
1849             sp_knot_moveto (drgknot, drg->point);
1850             drg->fireDraggables (true);
1851             drg->updateDependencies(true);
1852             did = true;
1853         }
1854
1855         g_slist_free(moving);
1856
1857         if (write_repr && did) {
1858             // we did an undoable action
1859             sp_document_maybe_done (sp_desktop_document (desktop), "grmovem", SP_VERB_CONTEXT_GRADIENT,
1860                                     _("Move gradient mid stop(s)"));
1861         }
1862     }
1863 }
1864
1865 void
1866 GrDrag::selected_move_screen (double x, double y)
1867 {
1868     gdouble zoom = desktop->current_zoom();
1869     gdouble zx = x / zoom;
1870     gdouble zy = y / zoom;
1871
1872     selected_move (zx, zy);
1873 }
1874
1875 /**
1876 Select the knot next to the last selected one and deselect all other selected.
1877 */
1878 GrDragger *
1879 GrDrag::select_next ()
1880 {
1881     GrDragger *d = NULL;
1882     if (selected == NULL || g_list_find(draggers, selected->data)->next == NULL) {
1883         if (draggers)
1884             d = (GrDragger *) draggers->data;
1885     } else {
1886         d = (GrDragger *) g_list_find(draggers, selected->data)->next->data;
1887     }
1888     if (d)
1889         setSelected (d);
1890     return d;
1891 }
1892
1893 /**
1894 Select the knot previous from the last selected one and deselect all other selected.
1895 */
1896 GrDragger *
1897 GrDrag::select_prev ()
1898 {
1899     GrDragger *d = NULL;
1900     if (selected == NULL || g_list_find(draggers, selected->data)->prev == NULL) {
1901         if (draggers)
1902             d = (GrDragger *) g_list_last (draggers)->data;
1903     } else {
1904         d = (GrDragger *) g_list_find(draggers, selected->data)->prev->data;
1905     }
1906     if (d)
1907         setSelected (d);
1908     return d;
1909 }
1910
1911
1912 // FIXME: i.m.o. an ugly function that I just made to work, but... aargh! (Johan)
1913 void
1914 GrDrag::deleteSelected (bool just_one)
1915 {
1916     if (!selected) return;
1917
1918     SPDocument *document = false;
1919
1920     struct StructStopInfo {
1921         SPStop * spstop;
1922         GrDraggable * draggable;
1923         SPGradient * gradient;
1924         SPGradient * vector;
1925     };
1926
1927     GSList *midstoplist = NULL;  // list of stops that must be deleted (will be deleted first)
1928     GSList *endstoplist = NULL;  // list of stops that must be deleted
1929     while (selected) {
1930         GrDragger *dragger = (GrDragger*) selected->data;
1931         for (GSList * drgble = dragger->draggables; drgble != NULL; drgble = drgble->next) {
1932             GrDraggable *draggable = (GrDraggable*) drgble->data;
1933             SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
1934             SPGradient *vector   = sp_gradient_get_forked_vector_if_necessary (gradient, false);
1935
1936             switch (draggable->point_type) {
1937                 case POINT_LG_MID:
1938                 case POINT_RG_MID1:
1939                 case POINT_RG_MID2:
1940                     {
1941                         SPStop *stop = sp_get_stop_i(vector, draggable->point_i);
1942                         // check if already present in list. (e.g. when both RG_MID1 and RG_MID2 were selected)
1943                         bool present = false;
1944                         for (GSList const * l = midstoplist; l != NULL; l = l->next) {
1945                             if ( (SPStop*)l->data == stop ) {
1946                                 present = true;
1947                                 break; // no need to search further.
1948                             }
1949                         }
1950                         if (!present)
1951                             midstoplist = g_slist_append(midstoplist, stop);
1952                     }
1953                     break;
1954                 case POINT_LG_BEGIN:
1955                 case POINT_LG_END:
1956                 case POINT_RG_CENTER:
1957                 case POINT_RG_R1:
1958                 case POINT_RG_R2:
1959                     {
1960                         SPStop *stop = NULL;
1961                         if ( (draggable->point_type == POINT_LG_BEGIN) || (draggable->point_type == POINT_RG_CENTER) ) {
1962                             stop = sp_first_stop(vector);
1963                         } else {
1964                             stop = sp_last_stop(vector);
1965                         }
1966                         if (stop) {
1967                             StructStopInfo *stopinfo = new StructStopInfo;
1968                             stopinfo->spstop = stop;
1969                             stopinfo->draggable = draggable;
1970                             stopinfo->gradient = gradient;
1971                             stopinfo->vector = vector;
1972                             // check if already present in list. (e.g. when both R1 and R2 were selected)
1973                             bool present = false;
1974                             for (GSList const * l = endstoplist; l != NULL; l = l->next) {
1975                                 if ( ((StructStopInfo*)l->data)->spstop == stopinfo->spstop ) {
1976                                     present = true;
1977                                     break; // no need to search further.
1978                                 }
1979                             }
1980                             if (!present)
1981                                 endstoplist = g_slist_append(endstoplist, stopinfo);
1982                         }
1983                     }
1984                     break;
1985                 default:
1986                     break;
1987             }
1988         }
1989         selected = g_list_remove(selected, dragger);
1990         if ( just_one ) break; // iterate once if just_one is set.
1991     }
1992     while (midstoplist) {
1993         SPStop *stop = (SPStop*) midstoplist->data;
1994         document = SP_OBJECT_DOCUMENT (stop);
1995         Inkscape::XML::Node * parent = SP_OBJECT_REPR(stop)->parent();
1996         parent->removeChild(SP_OBJECT_REPR(stop));
1997         midstoplist = g_slist_remove(midstoplist, stop);
1998     }
1999     while (endstoplist) {
2000         StructStopInfo *stopinfo  = (StructStopInfo*) endstoplist->data;
2001         document = SP_OBJECT_DOCUMENT (stopinfo->spstop);
2002
2003         // 2 is the minimum, cannot delete more than that without deleting the whole vector
2004         // cannot use vector->vector.stops.size() because the vector might be invalidated by deletion of a midstop
2005         // manually count the children, don't know if there already exists a function for this...
2006         int len = 0;
2007         for ( SPObject *child = sp_object_first_child(stopinfo->vector) ;
2008               child != NULL ;
2009               child = SP_OBJECT_NEXT(child) )
2010         {
2011             if ( SP_IS_STOP(child) )  len ++;
2012         }
2013         if (len > 2)
2014         {
2015             switch (stopinfo->draggable->point_type) {
2016                 case POINT_LG_BEGIN:
2017                     {
2018                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2019
2020                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
2021                         Geom::Point oldbegin = Geom::Point (lg->x1.computed, lg->y1.computed);
2022                         Geom::Point end = Geom::Point (lg->x2.computed, lg->y2.computed);
2023                         SPStop *stop = sp_first_stop(stopinfo->vector);
2024                         gdouble offset = stop->offset;
2025                         Geom::Point newbegin = oldbegin + offset * (end - oldbegin);
2026                         lg->x1.computed = newbegin[Geom::X];
2027                         lg->y1.computed = newbegin[Geom::Y];
2028
2029                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
2030                         sp_repr_set_svg_double(repr, "x1", lg->x1.computed);
2031                         sp_repr_set_svg_double(repr, "y1", lg->y1.computed);
2032                         stop->offset = 0;
2033                         sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", 0);
2034
2035                         // iterate through midstops to set new offset values such that they won't move on canvas.
2036                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2037                         stop = sp_next_stop(stop);
2038                         while ( stop != laststop ) {
2039                             stop->offset = (stop->offset - offset)/(1 - offset);
2040                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2041                             stop = sp_next_stop(stop);
2042                         }
2043                     }
2044                     break;
2045                 case POINT_LG_END:
2046                     {
2047                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2048
2049                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
2050                         Geom::Point begin = Geom::Point (lg->x1.computed, lg->y1.computed);
2051                         Geom::Point oldend = Geom::Point (lg->x2.computed, lg->y2.computed);
2052                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2053                         gdouble offset = laststop->offset;
2054                         Geom::Point newend = begin + offset * (oldend - begin);
2055                         lg->x2.computed = newend[Geom::X];
2056                         lg->y2.computed = newend[Geom::Y];
2057
2058                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
2059                         sp_repr_set_svg_double(repr, "x2", lg->x2.computed);
2060                         sp_repr_set_svg_double(repr, "y2", lg->y2.computed);
2061                         laststop->offset = 1;
2062                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
2063
2064                         // iterate through midstops to set new offset values such that they won't move on canvas.
2065                         SPStop *stop = sp_first_stop(stopinfo->vector);
2066                         stop = sp_next_stop(stop);
2067                         while ( stop != laststop ) {
2068                             stop->offset = stop->offset / offset;
2069                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2070                             stop = sp_next_stop(stop);
2071                         }
2072                     }
2073                     break;
2074                 case POINT_RG_CENTER:
2075                     {
2076                         SPStop *newfirst = sp_next_stop (stopinfo->spstop);
2077                         if (newfirst) {
2078                             newfirst->offset = 0;
2079                             sp_repr_set_css_double (SP_OBJECT_REPR (newfirst), "offset", 0);
2080                         }
2081                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2082                     }
2083                     break;
2084                 case POINT_RG_R1:
2085                 case POINT_RG_R2:
2086                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2087
2088                         SPRadialGradient *rg = SP_RADIALGRADIENT(stopinfo->gradient);
2089                         double oldradius = rg->r.computed;
2090                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2091                         gdouble offset = laststop->offset;
2092                         double newradius = offset * oldradius;
2093                         rg->r.computed = newradius;
2094
2095                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(rg);
2096                         sp_repr_set_svg_double(repr, "r", rg->r.computed);
2097                         laststop->offset = 1;
2098                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
2099
2100                         // iterate through midstops to set new offset values such that they won't move on canvas.
2101                         SPStop *stop = sp_first_stop(stopinfo->vector);
2102                         stop = sp_next_stop(stop);
2103                         while ( stop != laststop ) {
2104                             stop->offset = stop->offset / offset;
2105                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2106                             stop = sp_next_stop(stop);
2107                         }
2108                         break;
2109             }
2110         }
2111         else
2112         { // delete the gradient from the object. set fill to unset  FIXME: set to fill of unselected node?
2113             SPCSSAttr *css = sp_repr_css_attr_new ();
2114
2115             // stopinfo->spstop is the selected stop
2116             Inkscape::XML::Node *unselectedrepr = SP_OBJECT_REPR(stopinfo->vector)->firstChild();
2117             if (unselectedrepr == SP_OBJECT_REPR(stopinfo->spstop) ) {
2118                 unselectedrepr = unselectedrepr->next();
2119             }
2120
2121             if (unselectedrepr == NULL) {
2122                 if (stopinfo->draggable->fill_or_stroke) {
2123                     sp_repr_css_unset_property (css, "fill");
2124                 } else {
2125                     sp_repr_css_unset_property (css, "stroke");
2126                 }
2127             } else {
2128                 SPCSSAttr *stopcss = sp_repr_css_attr(unselectedrepr, "style");
2129                 if (stopinfo->draggable->fill_or_stroke) {
2130                     sp_repr_css_set_property(css, "fill", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
2131                     sp_repr_css_set_property(css, "fill-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
2132                 } else {
2133                     sp_repr_css_set_property(css, "stroke", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
2134                     sp_repr_css_set_property(css, "stroke-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
2135                 }
2136                 sp_repr_css_attr_unref (stopcss);
2137             }
2138
2139             sp_repr_css_change (SP_OBJECT_REPR (stopinfo->draggable->item), css, "style");
2140             sp_repr_css_attr_unref (css);
2141         }
2142
2143         endstoplist = g_slist_remove(endstoplist, stopinfo);
2144         delete stopinfo;
2145     }
2146
2147     if (document) {
2148         sp_document_done ( document, SP_VERB_CONTEXT_GRADIENT, _("Delete gradient stop(s)") );
2149     }
2150 }
2151
2152
2153 /*
2154   Local Variables:
2155   mode:c++
2156   c-file-style:"stroustrup"
2157   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
2158   indent-tabs-mode:nil
2159   fill-column:99
2160   End:
2161 */
2162 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :