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 const *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     SPDesktop *desktop = dragger->parent->desktop;
 545         SnapManager &m = desktop->namedview->snap_manager;
 546         double snap_dist = m.snapprefs.getObjectTolerance() / dragger->parent->desktop->current_zoom();
 547
 548     if (state & GDK_SHIFT_MASK) {
 549         // with Shift; unsnap if we carry more than one draggable
 550         if (dragger->draggables && dragger->draggables->next) {
 551             // create a new dragger
 552             GrDragger *dr_new = new GrDragger (dragger->parent, dragger->point, NULL);
 553             dragger->parent->draggers = g_list_prepend (dragger->parent->draggers, dr_new);
 554             // relink to it all but the first draggable in the list
 555             for (GSList const* i = dragger->draggables->next; i != NULL; i = i->next) {
 556                 GrDraggable *draggable = (GrDraggable *) i->data;
 557                 dr_new->addDraggable (draggable);
 558             }
 559             dr_new->updateKnotShape();
 560             g_slist_free (dragger->draggables->next);
 561             dragger->draggables->next = NULL;
 562             dragger->updateKnotShape();
 563             dragger->updateTip();
 564         }
 565     } else if (!(state & GDK_CONTROL_MASK)) {
 566         // without Shift or Ctrl; see if we need to snap to another dragger
 567         for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 568             GrDragger *d_new = (GrDragger *) di->data;
 569             if (dragger->mayMerge(d_new) && Geom::L2 (d_new->point - p) < snap_dist) {
 570
 571                 // Merge draggers:
 572                 for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 573                     GrDraggable *draggable = (GrDraggable *) i->data;
 574                     // copy draggable to d_new:
 575                     GrDraggable *da_new = new GrDraggable (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 576                     d_new->addDraggable (da_new);
 577                 }
 578
 579                 // unlink and delete this dragger
 580                 dragger->parent->draggers = g_list_remove (dragger->parent->draggers, dragger);
 581                 delete dragger;
 582
 583                 // update the new merged dragger
 584                 d_new->fireDraggables(true, false, true);
 585                 d_new->parent->updateLines();
 586                 d_new->parent->setSelected (d_new);
 587                 d_new->updateKnotShape ();
 588                 d_new->updateTip ();
 589                 d_new->updateDependencies(true);
 590                 sp_document_done (sp_desktop_document (d_new->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 591                                   _("Merge gradient handles"));
 592                 return;
 593             }
 594         }
 595     }
 596
 597     if (!((state & GDK_SHIFT_MASK) || ((state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK)))) {
 598         // Try snapping to the grid or guides
 599         m.setup(desktop);
 600         Inkscape::SnappedPoint s = m.freeSnap(Inkscape::SnapPreferences::SNAPPOINT_NODE, to_2geom(p), Inkscape::SNAPSOURCE_HANDLE);
 601         if (s.getSnapped()) {
 602             p = s.getPoint();
 603             sp_knot_moveto (knot, p);
 604         } else if (m.snapprefs.getSnapEnabledGlobally() && m.snapprefs.getSnapModeNode() && !(m.snapprefs.getSnapPostponedGlobally())) {
 605             bool was_snapped = false;
 606             double dist = NR_HUGE;
 607             // No snapping so far, let's see if we need to snap to any of the levels
 608             for (guint i = 0; i < dragger->parent->hor_levels.size(); i++) {
 609                 dist = fabs(p[Geom::Y] - dragger->parent->hor_levels[i]);
 610                 if (dist < snap_dist) {
 611                     p[Geom::Y] = dragger->parent->hor_levels[i];
 612                     s = Inkscape::SnappedPoint(p, Inkscape::SNAPSOURCE_HANDLE, Inkscape::SNAPTARGET_GRADIENTS_PARENT_BBOX, dist, snap_dist, false, false);
 613                     was_snapped = true;
 614                     sp_knot_moveto (knot, p);
 615                 }
 616             }
 617             for (guint i = 0; i < dragger->parent->vert_levels.size(); i++) {
 618                 dist = fabs(p[Geom::X] - dragger->parent->vert_levels[i]);
 619                 if (dist < snap_dist) {
 620                     p[Geom::X] = dragger->parent->vert_levels[i];
 621                     s = Inkscape::SnappedPoint(p, Inkscape::SNAPSOURCE_HANDLE, Inkscape::SNAPTARGET_GRADIENTS_PARENT_BBOX, dist, snap_dist, false, false);
 622                     was_snapped = true;
 623                     sp_knot_moveto (knot, p);
 624                 }
 625             }
 626             if (was_snapped) {
 627                 desktop->snapindicator->set_new_snaptarget(s);
 628             }
 629         }
 630     }
 631
 632     if (state & GDK_CONTROL_MASK) {
 633         Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 634         unsigned snaps = abs(prefs->getInt("/options/rotationsnapsperpi/value", 12));
 635         /* 0 means no snapping. */
 636
 637         // This list will store snap vectors from all draggables of dragger
 638         GSList *snap_vectors = NULL;
 639
 640         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) {
 641             GrDraggable *draggable = (GrDraggable *) i->data;
 642
 643             Geom::Point dr_snap(Geom::infinity(), Geom::infinity());
 644
 645             if (draggable->point_type == POINT_LG_BEGIN || draggable->point_type == POINT_LG_END) {
 646                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 647                     GrDragger *d_new = (GrDragger *) di->data;
 648                     if (d_new == dragger)
 649                         continue;
 650                     if (d_new->isA (draggable->item,
 651                                     draggable->point_type == POINT_LG_BEGIN? POINT_LG_END : POINT_LG_BEGIN,
 652                                     draggable->fill_or_stroke)) {
 653                         // found the other end of the linear gradient;
 654                         if (state & GDK_SHIFT_MASK) {
 655                             // moving linear around center
 656                             Geom::Point center = Geom::Point (0.5*(d_new->point + dragger->point));
 657                             dr_snap = center;
 658                         } else {
 659                             // moving linear around the other end
 660                             dr_snap = d_new->point;
 661                         }
 662                     }
 663                 }
 664             } else if (draggable->point_type == POINT_RG_R1 || draggable->point_type == POINT_RG_R2 || draggable->point_type == POINT_RG_FOCUS) {
 665                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 666                     GrDragger *d_new = (GrDragger *) di->data;
 667                     if (d_new == dragger)
 668                         continue;
 669                     if (d_new->isA (draggable->item,
 670                                     POINT_RG_CENTER,
 671                                     draggable->fill_or_stroke)) {
 672                         // found the center of the radial gradient;
 673                         dr_snap = d_new->point;
 674                     }
 675                 }
 676             } else if (draggable->point_type == POINT_RG_CENTER) {
 677                 // radial center snaps to hor/vert relative to its original position
 678                 dr_snap = dragger->point_original;
 679             }
 680
 681             boost::optional<Geom::Point> snap_vector;
 682             if (dr_snap.isFinite()) {
 683                 if (state & GDK_MOD1_MASK) {
 684                     // with Alt, snap to the original angle and its perpendiculars
 685                     snap_vector = get_snap_vector (p, dr_snap, M_PI/2, Geom::atan2 (dragger->point_original - dr_snap));
 686                 } else {
 687                     // with Ctrl, snap to M_PI/snaps
 688                     snap_vector = get_snap_vector (p, dr_snap, M_PI/snaps, 0);
 689                 }
 690             }
 691             if (snap_vector) {
 692                 snap_vectors = g_slist_prepend (snap_vectors, &(*snap_vector));
 693             }
 694         }
 695
 696         // Move by the smallest of snap vectors:
 697         Geom::Point move(9999, 9999);
 698         for (GSList const *i = snap_vectors; i != NULL; i = i->next) {
 699             Geom::Point *snap_vector = (Geom::Point *) i->data;
 700             if (Geom::L2(*snap_vector) < Geom::L2(move))
 701                 move = *snap_vector;
 702         }
 703         if (move[Geom::X] < 9999) {
 704             p += move;
 705             sp_knot_moveto (knot, p);
 706         }
 707
 708         g_slist_free(snap_vectors);
 709     }
 710
 711     drag->keep_selection = (bool) g_list_find(drag->selected, dragger);
 712     bool scale_radial = (state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK);
 713
 714     if (drag->keep_selection) {
 715         Geom::Point diff = p - dragger->point;
 716         drag->selected_move_nowrite (diff[Geom::X], diff[Geom::Y], scale_radial);
 717     } else {
 718         dragger->point = p;
 719         dragger->fireDraggables (false, scale_radial);
 720         dragger->updateDependencies(false);
 721     }
 722
 723 }
 724
 725
 726 static void
 727 gr_midpoint_limits(GrDragger *dragger, SPObject *server, Geom::Point *begin, Geom::Point *end, Geom::Point *low_lim, Geom::Point *high_lim, GSList **moving)
 728 {
 729
 730     GrDrag *drag = dragger->parent;
 731     // a midpoint dragger can (logically) only contain one GrDraggable
 732     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 733
 734     // get begin and end points between which dragging is allowed:
 735     // the draglimits are between knot(lowest_i - 1) and knot(highest_i + 1)
 736     *moving = g_slist_append(*moving, dragger);
 737
 738     guint lowest_i = draggable->point_i;
 739     guint highest_i = draggable->point_i;
 740     GrDragger *lowest_dragger = dragger;
 741     GrDragger *highest_dragger = dragger;
 742     if (dragger->isSelected()) {
 743         GrDragger* d_add;
 744         while ( true )
 745         {
 746             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 747             if ( d_add && g_list_find(drag->selected, d_add) ) {
 748                 lowest_i = lowest_i - 1;
 749                 *moving = g_slist_prepend(*moving, d_add);
 750                 lowest_dragger = d_add;
 751             } else {
 752                 break;
 753             }
 754         }
 755
 756         while ( true )
 757         {
 758             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 759             if ( d_add && g_list_find(drag->selected, d_add) ) {
 760                 highest_i = highest_i + 1;
 761                 *moving = g_slist_append(*moving, d_add);
 762                 highest_dragger = d_add;
 763             } else {
 764                 break;
 765             }
 766         }
 767     }
 768
 769     if ( SP_IS_LINEARGRADIENT(server) ) {
 770         guint num = SP_LINEARGRADIENT(server)->vector.stops.size();
 771         GrDragger *d_temp;
 772         if (lowest_i == 1) {
 773             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke);
 774         } else {
 775             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, lowest_i - 1, draggable->fill_or_stroke);
 776         }
 777         if (d_temp)
 778             *begin = d_temp->point;
 779
 780         d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, highest_i + 1, draggable->fill_or_stroke);
 781         if (d_temp == NULL) {
 782             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_END, num-1, draggable->fill_or_stroke);
 783         }
 784         if (d_temp)
 785             *end = d_temp->point;
 786     } else if ( SP_IS_RADIALGRADIENT(server) ) {
 787         guint num = SP_RADIALGRADIENT(server)->vector.stops.size();
 788         GrDragger *d_temp;
 789         if (lowest_i == 1) {
 790             d_temp = drag->getDraggerFor (draggable->item, POINT_RG_CENTER, 0, draggable->fill_or_stroke);
 791         } else {
 792             d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 793         }
 794         if (d_temp)
 795             *begin = d_temp->point;
 796
 797         d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 798         if (d_temp == NULL) {
 799             d_temp = drag->getDraggerFor (draggable->item, (draggable->point_type==POINT_RG_MID1) ? POINT_RG_R1 : POINT_RG_R2, num-1, draggable->fill_or_stroke);
 800         }
 801         if (d_temp)
 802             *end = d_temp->point;
 803     }
 804
 805     *low_lim  = dragger->point - (lowest_dragger->point - *begin);
 806     *high_lim = dragger->point - (highest_dragger->point - *end);
 807 }
 808
 809
 810
 811 /**
 812 Called when a midpoint knot is dragged.
 813 */
 814 static void
 815 gr_knot_moved_midpoint_handler(SPKnot */*knot*/, Geom::Point const &ppointer, guint state, gpointer data)
 816 {
 817     GrDragger *dragger = (GrDragger *) data;
 818     GrDrag *drag = dragger->parent;
 819     // a midpoint dragger can (logically) only contain one GrDraggable
 820     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 821
 822     // FIXME: take from prefs
 823     double snap_fraction = 0.1;
 824
 825     Geom::Point p = ppointer;
 826     Geom::Point begin(0,0), end(0,0);
 827     Geom::Point low_lim(0,0), high_lim(0,0);
 828
 829     SPObject *server = draggable->getServer();
 830
 831     GSList *moving = NULL;
 832     gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
 833
 834     if (state & GDK_CONTROL_MASK) {
 835         p = snap_vector_midpoint (p, low_lim, high_lim, snap_fraction);
 836     } else {
 837         p = snap_vector_midpoint (p, low_lim, high_lim, 0);
 838     }
 839     Geom::Point displacement = p - dragger->point;
 840
 841     for (GSList const* i = moving; i != NULL; i = i->next) {
 842         GrDragger *drg = (GrDragger*) i->data;
 843         SPKnot *drgknot = drg->knot;
 844         Geom::Point this_move = displacement;
 845         if (state & GDK_MOD1_MASK) {
 846             // FIXME: unify all these profiles (here, in nodepath, in tweak) in one place
 847             double alpha = 1.0;
 848             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
 849                 double x = Geom::L2(drg->point - dragger->point)/Geom::L2(end - dragger->point);
 850                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 851             } else { // drg is on the begin side from dragger
 852                 double x = Geom::L2(drg->point - dragger->point)/Geom::L2(begin - dragger->point);
 853                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 854             }
 855         }
 856         drg->point += this_move;
 857         sp_knot_moveto (drgknot, drg->point);
 858         drg->fireDraggables (false);
 859         drg->updateDependencies(false);
 860     }
 861
 862     g_slist_free(moving);
 863
 864     drag->keep_selection = dragger->isSelected();
 865 }
 866
 867
 868
 869 static void
 870 gr_knot_grabbed_handler (SPKnot */*knot*/, unsigned int /*state*/, gpointer data)
 871 {
 872     GrDragger *dragger = (GrDragger *) data;
 873
 874     sp_canvas_force_full_redraw_after_interruptions(dragger->parent->desktop->canvas, 5);
 875 }
 876
 877 /**
 878 Called when the mouse releases a dragger knot; changes gradient writing to repr, updates other draggers if needed
 879 */
 880 static void
 881 gr_knot_ungrabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 882 {
 883     GrDragger *dragger = (GrDragger *) data;
 884
 885     sp_canvas_end_forced_full_redraws(dragger->parent->desktop->canvas);
 886
 887     dragger->point_original = dragger->point = knot->pos;
 888
 889     if ((state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK)) {
 890         dragger->fireDraggables (true, true);
 891     } else {
 892         dragger->fireDraggables (true);
 893     }
 894
 895     for (GList *i = dragger->parent->selected; i != NULL; i = i->next) {
 896         GrDragger *d = (GrDragger *) i->data;
 897         if (d == dragger)
 898             continue;
 899         d->fireDraggables (true);
 900     }
 901
 902     // make this dragger selected
 903     if (!dragger->parent->keep_selection) {
 904         dragger->parent->setSelected (dragger);
 905     }
 906     dragger->parent->keep_selection = false;
 907
 908     dragger->updateDependencies(true);
 909
 910     // we did an undoable action
 911     sp_document_done (sp_desktop_document (dragger->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 912                       _("Move gradient handle"));
 913 }
 914
 915 /**
 916 Called when a dragger knot is clicked; selects the dragger or deletes it depending on the
 917 state of the keyboard keys
 918 */
 919 static void
 920 gr_knot_clicked_handler(SPKnot */*knot*/, guint state, gpointer data)
 921 {
 922     GrDragger *dragger = (GrDragger *) data;
 923     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 924     if (!draggable) return;
 925
 926     if ( (state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK ) ) {
 927     // delete this knot from vector
 928         SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
 929         gradient = sp_gradient_get_vector (gradient, false);
 930         if (gradient->vector.stops.size() > 2) { // 2 is the minimum
 931                 SPStop *stop = NULL;
 932                 switch (draggable->point_type) {  // if we delete first or last stop, move the next/previous to the edge
 933                 case POINT_LG_BEGIN:
 934                 case POINT_RG_CENTER:
 935                     stop = sp_first_stop(gradient);
 936                         {
 937                             SPStop *next = sp_next_stop (stop);
 938                                 if (next) {
 939                                         next->offset = 0;
 940                                         sp_repr_set_css_double (SP_OBJECT_REPR (next), "offset", 0);
 941                                 }
 942                         }
 943                     break;
 944                 case POINT_LG_END:
 945                 case POINT_RG_R1:
 946                 case POINT_RG_R2:
 947                     stop = sp_last_stop(gradient);
 948                     {
 949                             SPStop *prev = sp_prev_stop (stop, gradient);
 950                             if (prev) {
 951                                     prev->offset = 1;
 952                                     sp_repr_set_css_double (SP_OBJECT_REPR (prev), "offset", 1);
 953                             }
 954                         }
 955                     break;
 956                 case POINT_LG_MID:
 957                 case POINT_RG_MID1:
 958                 case POINT_RG_MID2:
 959                     stop = sp_get_stop_i(gradient, draggable->point_i);
 960                     break;
 961                 }
 962
 963                 SP_OBJECT_REPR(gradient)->removeChild(SP_OBJECT_REPR(stop));
 964                 sp_document_done (SP_OBJECT_DOCUMENT (gradient), SP_VERB_CONTEXT_GRADIENT,
 965                                   _("Delete gradient stop"));
 966         }
 967     } else {
 968     // select the dragger
 969         dragger->point_original = dragger->point;
 970
 971         if ( state & GDK_SHIFT_MASK ) {
 972             dragger->parent->setSelected (dragger, true, false);
 973         } else {
 974             dragger->parent->setSelected (dragger);
 975         }
 976     }
 977 }
 978
 979 /**
 980 Called when a dragger knot is doubleclicked; opens gradient editor with the stop from the first draggable
 981 */
 982 static void
 983 gr_knot_doubleclicked_handler (SPKnot */*knot*/, guint /*state*/, gpointer data)
 984 {
 985     GrDragger *dragger = (GrDragger *) data;
 986
 987     dragger->point_original = dragger->point;
 988
 989     if (dragger->draggables == NULL)
 990         return;
 991
 992     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 993     sp_item_gradient_edit_stop (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 994 }
 995
 996 /**
 997 Act upon all draggables of the dragger, setting them to the dragger's point
 998 */
 999 void
1000 GrDragger::fireDraggables (bool write_repr, bool scale_radial, bool merging_focus)
1001 {
1002     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1003         GrDraggable *draggable = (GrDraggable *) i->data;
1004
1005         // set local_change flag so that selection_changed callback does not regenerate draggers
1006         this->parent->local_change = true;
1007
1008         // change gradient, optionally writing to repr; prevent focus from moving if it's snapped
1009         // to the center, unless it's the first update upon merge when we must snap it to the point
1010         if (merging_focus ||
1011             !(draggable->point_type == POINT_RG_FOCUS && this->isA(draggable->item, POINT_RG_CENTER, draggable->point_i, draggable->fill_or_stroke)))
1012         {
1013             sp_item_gradient_set_coords (draggable->item, draggable->point_type, draggable->point_i, this->point, draggable->fill_or_stroke, write_repr, scale_radial);
1014         }
1015     }
1016 }
1017
1018 /**
1019 Checks if the dragger has a draggable with this point_type
1020  */
1021 bool
1022 GrDragger::isA (gint point_type)
1023 {
1024     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1025         GrDraggable *draggable = (GrDraggable *) i->data;
1026         if (draggable->point_type == point_type) {
1027             return true;
1028         }
1029     }
1030     return false;
1031 }
1032
1033 /**
1034 Checks if the dragger has a draggable with this item, point_type + point_i (number), fill_or_stroke
1035  */
1036 bool
1037 GrDragger::isA (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1038 {
1039     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1040         GrDraggable *draggable = (GrDraggable *) i->data;
1041         if ( (draggable->point_type == point_type) && (draggable->point_i == point_i) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
1042             return true;
1043         }
1044     }
1045     return false;
1046 }
1047
1048 /**
1049 Checks if the dragger has a draggable with this item, point_type, fill_or_stroke
1050  */
1051 bool
1052 GrDragger::isA (SPItem *item, gint point_type, bool fill_or_stroke)
1053 {
1054     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1055         GrDraggable *draggable = (GrDraggable *) i->data;
1056         if ( (draggable->point_type == point_type) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
1057             return true;
1058         }
1059     }
1060     return false;
1061 }
1062
1063 bool
1064 GrDraggable::mayMerge (GrDraggable *da2)
1065 {
1066     if ((this->item == da2->item) && (this->fill_or_stroke == da2->fill_or_stroke)) {
1067         // we must not merge the points of the same gradient!
1068         if (!((this->point_type == POINT_RG_FOCUS && da2->point_type == POINT_RG_CENTER) ||
1069               (this->point_type == POINT_RG_CENTER && da2->point_type == POINT_RG_FOCUS))) {
1070             // except that we can snap center and focus together
1071             return false;
1072         }
1073     }
1074     // disable merging of midpoints.
1075     if ( (this->point_type == POINT_LG_MID) || (da2->point_type == POINT_LG_MID)
1076          || (this->point_type == POINT_RG_MID1) || (da2->point_type == POINT_RG_MID1)
1077          || (this->point_type == POINT_RG_MID2) || (da2->point_type == POINT_RG_MID2) )
1078         return false;
1079
1080     return true;
1081 }
1082
1083 bool
1084 GrDragger::mayMerge (GrDragger *other)
1085 {
1086     if (this == other)
1087         return false;
1088
1089     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
1090         GrDraggable *da1 = (GrDraggable *) i->data;
1091         for (GSList const* j = other->draggables; j != NULL; j = j->next) { // for all draggables of other
1092             GrDraggable *da2 = (GrDraggable *) j->data;
1093             if (!da1->mayMerge(da2))
1094                 return false;
1095         }
1096     }
1097     return true;
1098 }
1099
1100 bool
1101 GrDragger::mayMerge (GrDraggable *da2)
1102 {
1103     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
1104         GrDraggable *da1 = (GrDraggable *) i->data;
1105         if (!da1->mayMerge(da2))
1106             return false;
1107     }
1108     return true;
1109 }
1110
1111 /**
1112 Updates the statusbar tip of the dragger knot, based on its draggables
1113  */
1114 void
1115 GrDragger::updateTip ()
1116 {
1117         if (this->knot && this->knot->tip) {
1118                 g_free (this->knot->tip);
1119                 this->knot->tip = NULL;
1120         }
1121
1122     if (g_slist_length (this->draggables) == 1) {
1123         GrDraggable *draggable = (GrDraggable *) this->draggables->data;
1124         char *item_desc = sp_item_description(draggable->item);
1125         switch (draggable->point_type) {
1126             case POINT_LG_MID:
1127             case POINT_RG_MID1:
1128             case POINT_RG_MID2:
1129                 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"),
1130                                                    _(gr_knot_descr[draggable->point_type]),
1131                                                    draggable->point_i,
1132                                                    item_desc,
1133                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
1134                 break;
1135
1136             default:
1137                 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"),
1138                                                    _(gr_knot_descr[draggable->point_type]),
1139                                                    item_desc,
1140                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
1141                 break;
1142         }
1143         g_free(item_desc);
1144     } else if (g_slist_length (draggables) == 2 && isA (POINT_RG_CENTER) && isA (POINT_RG_FOCUS)) {
1145         this->knot->tip = g_strdup_printf (_("Radial gradient <b>center</b> and <b>focus</b>; drag with <b>Shift</b> to separate focus"));
1146     } else {
1147         int length = g_slist_length (this->draggables);
1148         this->knot->tip = g_strdup_printf (ngettext("Gradient point shared by <b>%d</b> gradient; drag with <b>Shift</b> to separate",
1149                                                     "Gradient point shared by <b>%d</b> gradients; drag with <b>Shift</b> to separate",
1150                                                     length),
1151                                            length);
1152     }
1153 }
1154
1155 /**
1156 Adds a draggable to the dragger
1157  */
1158 void
1159 GrDragger::updateKnotShape ()
1160 {
1161     if (!draggables)
1162         return;
1163     GrDraggable *last = (GrDraggable *) g_slist_last(draggables)->data;
1164     g_object_set (G_OBJECT (this->knot->item), "shape", gr_knot_shapes[last->point_type], NULL);
1165 }
1166
1167 /**
1168 Adds a draggable to the dragger
1169  */
1170 void
1171 GrDragger::addDraggable (GrDraggable *draggable)
1172 {
1173     this->draggables = g_slist_prepend (this->draggables, draggable);
1174
1175     this->updateTip();
1176 }
1177
1178
1179 /**
1180 Moves this dragger to the point of the given draggable, acting upon all other draggables
1181  */
1182 void
1183 GrDragger::moveThisToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1184 {
1185     this->point = sp_item_gradient_get_coords (item, point_type, point_i, fill_or_stroke);
1186     this->point_original = this->point;
1187
1188     sp_knot_moveto (this->knot, this->point);
1189
1190     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1191         GrDraggable *da = (GrDraggable *) i->data;
1192         if ( (da->item == item) &&
1193              (point_type == -1 || da->point_type == point_type) &&
1194              (point_i == -1 || da->point_i == point_i) &&
1195              (da->fill_or_stroke == fill_or_stroke) ) {
1196             continue;
1197         }
1198         sp_item_gradient_set_coords (da->item, da->point_type, da->point_i, this->point, da->fill_or_stroke, write_repr, false);
1199     }
1200     // FIXME: here we should also call this->updateDependencies(write_repr); to propagate updating, but how to prevent loops?
1201 }
1202
1203
1204 /**
1205 Moves all midstop draggables that depend on this one
1206  */
1207 void
1208 GrDragger::updateMidstopDependencies (GrDraggable *draggable, bool write_repr) {
1209     SPObject *server = draggable->getServer();
1210     if (!server)
1211         return;
1212     guint num = SP_GRADIENT(server)->vector.stops.size();
1213     if (num <= 2) return;
1214
1215     if ( SP_IS_LINEARGRADIENT(server) ) {
1216         for ( guint i = 1; i < num - 1; i++ ) {
1217             this->moveOtherToDraggable (draggable->item, POINT_LG_MID, i, draggable->fill_or_stroke, write_repr);
1218         }
1219     } else  if ( SP_IS_RADIALGRADIENT(server) ) {
1220         for ( guint i = 1; i < num - 1; i++ ) {
1221             this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, i, draggable->fill_or_stroke, write_repr);
1222             this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, i, draggable->fill_or_stroke, write_repr);
1223         }
1224     }
1225 }
1226
1227
1228 /**
1229 Moves all draggables that depend on this one
1230  */
1231 void
1232 GrDragger::updateDependencies (bool write_repr)
1233 {
1234     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1235         GrDraggable *draggable = (GrDraggable *) i->data;
1236         switch (draggable->point_type) {
1237             case POINT_LG_BEGIN:
1238                 {
1239                     // the end point is dependent only when dragging with ctrl+shift
1240                     this->moveOtherToDraggable (draggable->item, POINT_LG_END, -1, draggable->fill_or_stroke, write_repr);
1241
1242                     this->updateMidstopDependencies (draggable, write_repr);
1243                 }
1244                 break;
1245             case POINT_LG_END:
1246                 {
1247                     // the begin point is dependent only when dragging with ctrl+shift
1248                     this->moveOtherToDraggable (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke, write_repr);
1249
1250                     this->updateMidstopDependencies (draggable, write_repr);
1251                 }
1252                 break;
1253             case POINT_LG_MID:
1254                 // no other nodes depend on mid points.
1255                 break;
1256             case POINT_RG_R2:
1257                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1258                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1259                 this->updateMidstopDependencies (draggable, write_repr);
1260                 break;
1261             case POINT_RG_R1:
1262                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1263                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1264                 this->updateMidstopDependencies (draggable, write_repr);
1265                 break;
1266             case POINT_RG_CENTER:
1267                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1268                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1269                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1270                 this->updateMidstopDependencies (draggable, write_repr);
1271                 break;
1272             case POINT_RG_FOCUS:
1273                 // nothing can depend on that
1274                 break;
1275             case POINT_RG_MID1:
1276                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, draggable->point_i, draggable->fill_or_stroke, write_repr);
1277                 break;
1278             case POINT_RG_MID2:
1279                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, draggable->point_i, draggable->fill_or_stroke, write_repr);
1280                 break;
1281             default:
1282                 break;
1283         }
1284     }
1285 }
1286
1287
1288
1289 GrDragger::GrDragger (GrDrag *parent, Geom::Point p, GrDraggable *draggable)
1290   : point(p),
1291     point_original(p)
1292 {
1293     this->draggables = NULL;
1294
1295     this->parent = parent;
1296
1297     // create the knot
1298     this->knot = sp_knot_new (parent->desktop, NULL);
1299     this->knot->setMode(SP_KNOT_MODE_XOR);
1300     this->knot->setFill(GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_MOUSEOVER, GR_KNOT_COLOR_MOUSEOVER);
1301     this->knot->setStroke(0x0000007f, 0x0000007f, 0x0000007f);
1302     sp_knot_update_ctrl(this->knot);
1303
1304     // move knot to the given point
1305     sp_knot_set_position (this->knot, p, SP_KNOT_STATE_NORMAL);
1306     sp_knot_show (this->knot);
1307
1308     // connect knot's signals
1309     if ( (draggable)  // it can be NULL if a node in unsnapped (eg. focus point unsnapped from center)
1310                        // luckily, midstops never snap to other nodes so are never unsnapped...
1311          && ( (draggable->point_type == POINT_LG_MID)
1312               || (draggable->point_type == POINT_RG_MID1)
1313               || (draggable->point_type == POINT_RG_MID2) ) )
1314     {
1315         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_midpoint_handler), this);
1316     } else {
1317         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_handler), this);
1318     }
1319     g_signal_connect (G_OBJECT (this->knot), "clicked", G_CALLBACK (gr_knot_clicked_handler), this);
1320     g_signal_connect (G_OBJECT (this->knot), "doubleclicked", G_CALLBACK (gr_knot_doubleclicked_handler), this);
1321     g_signal_connect (G_OBJECT (this->knot), "grabbed", G_CALLBACK (gr_knot_grabbed_handler), this);
1322     g_signal_connect (G_OBJECT (this->knot), "ungrabbed", G_CALLBACK (gr_knot_ungrabbed_handler), this);
1323
1324     // add the initial draggable
1325     if (draggable)
1326         this->addDraggable (draggable);
1327     updateKnotShape();
1328 }
1329
1330 GrDragger::~GrDragger ()
1331 {
1332     // unselect if it was selected
1333     this->parent->setDeselected(this);
1334
1335     // disconnect signals
1336     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_moved_handler), this);
1337     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_clicked_handler), this);
1338     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_doubleclicked_handler), this);
1339     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_grabbed_handler), this);
1340     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_ungrabbed_handler), this);
1341
1342     /* unref should call destroy */
1343     g_object_unref (G_OBJECT (this->knot));
1344
1345     // delete all draggables
1346     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1347         delete ((GrDraggable *) i->data);
1348     }
1349     g_slist_free (this->draggables);
1350     this->draggables = NULL;
1351 }
1352
1353 /**
1354 Select the dragger which has the given draggable.
1355 */
1356 GrDragger *
1357 GrDrag::getDraggerFor (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1358 {
1359     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1360         GrDragger *dragger = (GrDragger *) i->data;
1361         for (GSList const* j = dragger->draggables; j != NULL; j = j->next) {
1362             GrDraggable *da2 = (GrDraggable *) j->data;
1363             if ( (da2->item == item) &&
1364                  (point_type == -1 || da2->point_type == point_type) && // -1 means this does not matter
1365                  (point_i == -1 || da2->point_i == point_i) && // -1 means this does not matter
1366                  (da2->fill_or_stroke == fill_or_stroke)) {
1367                 return (dragger);
1368             }
1369         }
1370     }
1371     return NULL;
1372 }
1373
1374
1375 void
1376 GrDragger::moveOtherToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1377 {
1378     GrDragger *d = this->parent->getDraggerFor (item, point_type, point_i, fill_or_stroke);
1379     if (d && d !=  this) {
1380         d->moveThisToDraggable (item, point_type, point_i, fill_or_stroke, write_repr);
1381     }
1382 }
1383
1384
1385 /**
1386   Draw this dragger as selected
1387 */
1388 void
1389 GrDragger::select()
1390 {
1391     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_SELECTED;
1392     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_SELECTED, NULL);
1393 }
1394
1395 /**
1396   Draw this dragger as normal (deselected)
1397 */
1398 void
1399 GrDragger::deselect()
1400 {
1401     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_NORMAL;
1402     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_NORMAL, NULL);
1403 }
1404
1405 bool
1406 GrDragger::isSelected()
1407 {
1408     return g_list_find (parent->selected, this);
1409 }
1410
1411 /**
1412 \brief Deselect all stops/draggers (private)
1413 */
1414 void
1415 GrDrag::deselect_all()
1416 {
1417     while (selected) {
1418         ( (GrDragger*) selected->data)->deselect();
1419         selected = g_list_remove(selected, selected->data);
1420     }
1421 }
1422
1423 /**
1424 \brief Deselect all stops/draggers (public; emits signal)
1425 */
1426 void
1427 GrDrag::deselectAll()
1428 {
1429     deselect_all();
1430     this->desktop->emitToolSubselectionChanged(NULL);
1431 }
1432
1433 /**
1434 \brief Select all stops/draggers
1435 */
1436 void
1437 GrDrag::selectAll()
1438 {
1439     for (GList *l = this->draggers; l != NULL; l = l->next) {
1440         GrDragger *d = ((GrDragger *) l->data);
1441         setSelected (d, true, true);
1442     }
1443 }
1444
1445 /**
1446 \brief Select all stops/draggers that match the coords
1447 */
1448 void
1449 GrDrag::selectByCoords(std::vector<Geom::Point> coords)
1450 {
1451     for (GList *l = this->draggers; l != NULL; l = l->next) {
1452         GrDragger *d = ((GrDragger *) l->data);
1453         for (guint k = 0; k < coords.size(); k++) {
1454             if (Geom::L2 (d->point - coords[k]) < 1e-4) {
1455                 setSelected (d, true, true);
1456             }
1457         }
1458     }
1459 }
1460
1461
1462 /**
1463 \brief Select all stops/draggers that fall within the rect
1464 */
1465 void
1466 GrDrag::selectRect(Geom::Rect const &r)
1467 {
1468     for (GList *l = this->draggers; l != NULL; l = l->next) {
1469         GrDragger *d = ((GrDragger *) l->data);
1470         if (r.contains(d->point)) {
1471            setSelected (d, true, true);
1472         }
1473     }
1474 }
1475
1476 /**
1477 \brief Select a dragger
1478 \param dragger       The dragger to select
1479 \param add_to_selection   If true, add to selection, otherwise deselect others
1480 \param override      If true, always select this node, otherwise toggle selected status
1481 */
1482 void
1483 GrDrag::setSelected (GrDragger *dragger, bool add_to_selection, bool override)
1484 {
1485     GrDragger *seldragger = NULL;
1486
1487     if (add_to_selection) {
1488         if (!dragger) return;
1489         if (override) {
1490             if (!g_list_find(selected, dragger)) {
1491                 selected = g_list_prepend(selected, dragger);
1492             }
1493             dragger->select();
1494             seldragger = dragger;
1495         } else { // toggle
1496             if (g_list_find(selected, dragger)) {
1497                 selected = g_list_remove(selected, dragger);
1498                 dragger->deselect();
1499                 if (selected) {
1500                     seldragger = (GrDragger*) selected->data; // select the dragger that is first in the list
1501                 }
1502             } else {
1503                 selected = g_list_prepend(selected, dragger);
1504                 dragger->select();
1505                 seldragger = dragger;
1506             }
1507         }
1508     } else {
1509         deselect_all();
1510         if (dragger) {
1511             selected = g_list_prepend(selected, dragger);
1512             dragger->select();
1513             seldragger = dragger;
1514         }
1515     }
1516     if (seldragger) {
1517         this->desktop->emitToolSubselectionChanged((gpointer) seldragger);
1518     }
1519 }
1520
1521 /**
1522 \brief Deselect a dragger
1523 \param dragger       The dragger to deselect
1524 */
1525 void
1526 GrDrag::setDeselected (GrDragger *dragger)
1527 {
1528     if (g_list_find(selected, dragger)) {
1529         selected = g_list_remove(selected, dragger);
1530         dragger->deselect();
1531     }
1532     this->desktop->emitToolSubselectionChanged((gpointer) (selected ? selected->data : NULL ));
1533 }
1534
1535
1536
1537 /**
1538 Create a line from p1 to p2 and add it to the lines list
1539  */
1540 void
1541 GrDrag::addLine (SPItem *item, Geom::Point p1, Geom::Point p2, guint32 rgba)
1542 {
1543     SPCanvasItem *line = sp_canvas_item_new(sp_desktop_controls(this->desktop),
1544                                                             SP_TYPE_CTRLLINE, NULL);
1545     sp_canvas_item_move_to_z(line, 0);
1546     SP_CTRLLINE(line)->item = item;
1547     sp_ctrlline_set_coords(SP_CTRLLINE(line), p1, p2);
1548     if (rgba != GR_LINE_COLOR_FILL) // fill is the default, so don't set color for it to speed up redraw
1549         sp_ctrlline_set_rgba32 (SP_CTRLLINE(line), rgba);
1550     sp_canvas_item_show (line);
1551     this->lines = g_slist_append (this->lines, line);
1552 }
1553
1554 /**
1555 If there already exists a dragger within MERGE_DIST of p, add the draggable to it; otherwise create
1556 new dragger and add it to draggers list
1557  */
1558 void
1559 GrDrag::addDragger (GrDraggable *draggable)
1560 {
1561     Geom::Point p = sp_item_gradient_get_coords (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
1562
1563     for (GList *i = this->draggers; i != NULL; i = i->next) {
1564         GrDragger *dragger = (GrDragger *) i->data;
1565         if (dragger->mayMerge (draggable) && Geom::L2 (dragger->point - p) < MERGE_DIST) {
1566             // distance is small, merge this draggable into dragger, no need to create new dragger
1567             dragger->addDraggable (draggable);
1568             dragger->updateKnotShape();
1569             return;
1570         }
1571     }
1572
1573     GrDragger *new_dragger = new GrDragger(this, p, draggable);
1574     // fixme: draggers should be added AFTER the last one: this way tabbing through them will be from begin to end.
1575     this->draggers = g_list_append (this->draggers, new_dragger);
1576 }
1577
1578 /**
1579 Add draggers for the radial gradient rg on item
1580 */
1581 void
1582 GrDrag::addDraggersRadial (SPRadialGradient *rg, SPItem *item, bool fill_or_stroke)
1583 {
1584     addDragger (new GrDraggable (item, POINT_RG_CENTER, 0, fill_or_stroke));
1585     guint num = rg->vector.stops.size();
1586     if (num > 2) {
1587         for ( guint i = 1; i < num - 1; i++ ) {
1588             addDragger (new GrDraggable (item, POINT_RG_MID1, i, fill_or_stroke));
1589         }
1590     }
1591     addDragger (new GrDraggable (item, POINT_RG_R1, num-1, fill_or_stroke));
1592     if (num > 2) {
1593         for ( guint i = 1; i < num - 1; i++ ) {
1594             addDragger (new GrDraggable (item, POINT_RG_MID2, i, fill_or_stroke));
1595         }
1596     }
1597     addDragger (new GrDraggable (item, POINT_RG_R2, num-1, fill_or_stroke));
1598     addDragger (new GrDraggable (item, POINT_RG_FOCUS, 0, fill_or_stroke));
1599 }
1600
1601 /**
1602 Add draggers for the linear gradient lg on item
1603 */
1604 void
1605 GrDrag::addDraggersLinear (SPLinearGradient *lg, SPItem *item, bool fill_or_stroke)
1606 {
1607     addDragger (new GrDraggable (item, POINT_LG_BEGIN, 0, fill_or_stroke));
1608     guint num = lg->vector.stops.size();
1609     if (num > 2) {
1610         for ( guint i = 1; i < num - 1; i++ ) {
1611             addDragger (new GrDraggable (item, POINT_LG_MID, i, fill_or_stroke));
1612         }
1613     }
1614     addDragger (new GrDraggable (item, POINT_LG_END, num-1, fill_or_stroke));
1615 }
1616
1617 /**
1618 Artificially grab the knot of this dragger; used by the gradient context
1619 */
1620 void
1621 GrDrag::grabKnot (GrDragger *dragger, gint x, gint y, guint32 etime)
1622 {
1623     if (dragger) {
1624         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1625     }
1626 }
1627
1628 /**
1629 Artificially grab the knot of the dragger with this draggable; used by the gradient context
1630 */
1631 void
1632 GrDrag::grabKnot (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, gint x, gint y, guint32 etime)
1633 {
1634     GrDragger *dragger = getDraggerFor (item, point_type, point_i, fill_or_stroke);
1635     if (dragger) {
1636         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1637     }
1638 }
1639
1640 /**
1641 Regenerates the draggers list from the current selection; is called when selection is changed or
1642 modified, also when a radial dragger needs to update positions of other draggers in the gradient
1643 */
1644 void
1645 GrDrag::updateDraggers ()
1646 {
1647     while (selected) {
1648         selected = g_list_remove(selected, selected->data);
1649     }
1650     // delete old draggers
1651     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1652         delete ((GrDragger *) i->data);
1653     }
1654     g_list_free (this->draggers);
1655     this->draggers = NULL;
1656
1657     g_return_if_fail (this->selection != NULL);
1658
1659     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1660
1661         SPItem *item = SP_ITEM(i->data);
1662         SPStyle *style = SP_OBJECT_STYLE (item);
1663
1664         if (style && (style->fill.isPaintserver())) {
1665             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1666             if (SP_IS_LINEARGRADIENT (server)) {
1667                 addDraggersLinear (SP_LINEARGRADIENT (server), item, true);
1668             } else if (SP_IS_RADIALGRADIENT (server)) {
1669                 addDraggersRadial (SP_RADIALGRADIENT (server), item, true);
1670             }
1671         }
1672
1673         if (style && (style->stroke.isPaintserver())) {
1674             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1675             if (SP_IS_LINEARGRADIENT (server)) {
1676                 addDraggersLinear (SP_LINEARGRADIENT (server), item, false);
1677             } else if (SP_IS_RADIALGRADIENT (server)) {
1678                 addDraggersRadial (SP_RADIALGRADIENT (server), item, false);
1679             }
1680         }
1681     }
1682 }
1683
1684 /**
1685 Regenerates the lines list from the current selection; is called on each move of a dragger, so that
1686 lines are always in sync with the actual gradient
1687 */
1688 void
1689 GrDrag::updateLines ()
1690 {
1691     // delete old lines
1692     for (GSList const *i = this->lines; i != NULL; i = i->next) {
1693         gtk_object_destroy( GTK_OBJECT (i->data));
1694     }
1695     g_slist_free (this->lines);
1696     this->lines = NULL;
1697
1698     g_return_if_fail (this->selection != NULL);
1699
1700     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1701
1702         SPItem *item = SP_ITEM(i->data);
1703
1704         SPStyle *style = SP_OBJECT_STYLE (item);
1705
1706         if (style && (style->fill.isPaintserver())) {
1707             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1708             if (SP_IS_LINEARGRADIENT (server)) {
1709                 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);
1710             } else if (SP_IS_RADIALGRADIENT (server)) {
1711                 Geom::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, true);
1712                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, true), GR_LINE_COLOR_FILL);
1713                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, true), GR_LINE_COLOR_FILL);
1714             }
1715         }
1716
1717         if (style && (style->stroke.isPaintserver())) {
1718             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1719             if (SP_IS_LINEARGRADIENT (server)) {
1720                 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);
1721             } else if (SP_IS_RADIALGRADIENT (server)) {
1722                 Geom::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, false);
1723                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, false), GR_LINE_COLOR_STROKE);
1724                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, false), GR_LINE_COLOR_STROKE);
1725             }
1726         }
1727     }
1728 }
1729
1730 /**
1731 Regenerates the levels list from the current selection
1732 */
1733 void
1734 GrDrag::updateLevels ()
1735 {
1736     hor_levels.clear();
1737     vert_levels.clear();
1738
1739     g_return_if_fail (this->selection != NULL);
1740
1741     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1742         SPItem *item = SP_ITEM(i->data);
1743         Geom::OptRect rect = sp_item_bbox_desktop (item);
1744         if (rect) {
1745             // Remember the edges of the bbox and the center axis
1746             hor_levels.push_back(rect->min()[Geom::Y]);
1747             hor_levels.push_back(rect->max()[Geom::Y]);
1748             hor_levels.push_back(0.5 * (rect->min()[Geom::Y] + rect->max()[Geom::Y]));
1749             vert_levels.push_back(rect->min()[Geom::X]);
1750             vert_levels.push_back(rect->max()[Geom::X]);
1751             vert_levels.push_back(0.5 * (rect->min()[Geom::X] + rect->max()[Geom::X]));
1752         }
1753     }
1754 }
1755
1756 void
1757 GrDrag::selected_reverse_vector ()
1758 {
1759     if (selected == NULL)
1760         return;
1761
1762     for (GSList const* i = ( (GrDragger*) selected->data )->draggables; i != NULL; i = i->next) {
1763         GrDraggable *draggable = (GrDraggable *) i->data;
1764
1765         sp_item_gradient_reverse_vector (draggable->item, draggable->fill_or_stroke);
1766     }
1767 }
1768
1769 void
1770 GrDrag::selected_move_nowrite (double x, double y, bool scale_radial)
1771 {
1772     selected_move (x, y, false, scale_radial);
1773 }
1774
1775 void
1776 GrDrag::selected_move (double x, double y, bool write_repr, bool scale_radial)
1777 {
1778     if (selected == NULL)
1779         return;
1780
1781     bool did = false;
1782
1783     for (GList *i = selected; i != NULL; i = i->next) {
1784         GrDragger *d = (GrDragger *) i->data;
1785
1786         if (!d->isA(POINT_LG_MID) && !d->isA(POINT_RG_MID1) && !d->isA(POINT_RG_MID2)) {
1787             // if this is an endpoint,
1788
1789             // Moving an rg center moves its focus and radii as well.
1790             // therefore, if this is a focus or radius and if selection
1791             // contains the center as well, do not move this one
1792             if (d->isA(POINT_RG_R1) || d->isA(POINT_RG_R2) ||
1793                 (d->isA(POINT_RG_FOCUS) && !d->isA(POINT_RG_CENTER))) {
1794                 bool skip_radius_with_center = false;
1795                 for (GList *di = selected; di != NULL; di = di->next) {
1796                     GrDragger *d_new = (GrDragger *) di->data;
1797                     if (d_new->isA (((GrDraggable *) d->draggables->data)->item,
1798                                     POINT_RG_CENTER,
1799                                     0,
1800                                     ((GrDraggable *) d->draggables->data)->fill_or_stroke)) {
1801                         // FIXME: here we take into account only the first draggable!
1802                         skip_radius_with_center = true;
1803                     }
1804                 }
1805                 if (skip_radius_with_center)
1806                     continue;
1807             }
1808
1809             did = true;
1810             d->point += Geom::Point (x, y);
1811             d->point_original = d->point;
1812             sp_knot_moveto (d->knot, d->point);
1813
1814             d->fireDraggables (write_repr, scale_radial);
1815
1816             d->updateDependencies(write_repr);
1817         }
1818     }
1819
1820     if (write_repr && did) {
1821         // we did an undoable action
1822         sp_document_maybe_done (sp_desktop_document (desktop), "grmoveh", SP_VERB_CONTEXT_GRADIENT,
1823                                 _("Move gradient handle(s)"));
1824         return;
1825     }
1826
1827     if (!did) { // none of the end draggers are selected, so let's try to move the mids
1828
1829         GrDragger *dragger = (GrDragger *) selected->data;
1830         // a midpoint dragger can (logically) only contain one GrDraggable
1831         GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
1832
1833         Geom::Point begin(0,0), end(0,0);
1834         Geom::Point low_lim(0,0), high_lim(0,0);
1835
1836         SPObject *server = draggable->getServer();
1837         GSList *moving = NULL;
1838         gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
1839
1840         Geom::Point p(x, y);
1841         p = snap_vector_midpoint (dragger->point + p, low_lim, high_lim, 0);
1842         Geom::Point displacement = p - dragger->point;
1843
1844         for (GSList const* i = moving; i != NULL; i = i->next) {
1845             GrDragger *drg = (GrDragger*) i->data;
1846             SPKnot *drgknot = drg->knot;
1847             drg->point += displacement;
1848             sp_knot_moveto (drgknot, drg->point);
1849             drg->fireDraggables (true);
1850             drg->updateDependencies(true);
1851             did = true;
1852         }
1853
1854         g_slist_free(moving);
1855
1856         if (write_repr && did) {
1857             // we did an undoable action
1858             sp_document_maybe_done (sp_desktop_document (desktop), "grmovem", SP_VERB_CONTEXT_GRADIENT,
1859                                     _("Move gradient mid stop(s)"));
1860         }
1861     }
1862 }
1863
1864 void
1865 GrDrag::selected_move_screen (double x, double y)
1866 {
1867     gdouble zoom = desktop->current_zoom();
1868     gdouble zx = x / zoom;
1869     gdouble zy = y / zoom;
1870
1871     selected_move (zx, zy);
1872 }
1873
1874 /**
1875 Select the knot next to the last selected one and deselect all other selected.
1876 */
1877 GrDragger *
1878 GrDrag::select_next ()
1879 {
1880     GrDragger *d = NULL;
1881     if (selected == NULL || g_list_find(draggers, selected->data)->next == NULL) {
1882         if (draggers)
1883             d = (GrDragger *) draggers->data;
1884     } else {
1885         d = (GrDragger *) g_list_find(draggers, selected->data)->next->data;
1886     }
1887     if (d)
1888         setSelected (d);
1889     return d;
1890 }
1891
1892 /**
1893 Select the knot previous from the last selected one and deselect all other selected.
1894 */
1895 GrDragger *
1896 GrDrag::select_prev ()
1897 {
1898     GrDragger *d = NULL;
1899     if (selected == NULL || g_list_find(draggers, selected->data)->prev == NULL) {
1900         if (draggers)
1901             d = (GrDragger *) g_list_last (draggers)->data;
1902     } else {
1903         d = (GrDragger *) g_list_find(draggers, selected->data)->prev->data;
1904     }
1905     if (d)
1906         setSelected (d);
1907     return d;
1908 }
1909
1910
1911 // FIXME: i.m.o. an ugly function that I just made to work, but... aargh! (Johan)
1912 void
1913 GrDrag::deleteSelected (bool just_one)
1914 {
1915     if (!selected) return;
1916
1917     SPDocument *document = false;
1918
1919     struct StructStopInfo {
1920         SPStop * spstop;
1921         GrDraggable * draggable;
1922         SPGradient * gradient;
1923         SPGradient * vector;
1924     };
1925
1926     GSList *midstoplist = NULL;  // list of stops that must be deleted (will be deleted first)
1927     GSList *endstoplist = NULL;  // list of stops that must be deleted
1928     while (selected) {
1929         GrDragger *dragger = (GrDragger*) selected->data;
1930         for (GSList * drgble = dragger->draggables; drgble != NULL; drgble = drgble->next) {
1931             GrDraggable *draggable = (GrDraggable*) drgble->data;
1932             SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
1933             SPGradient *vector   = sp_gradient_get_forked_vector_if_necessary (gradient, false);
1934
1935             switch (draggable->point_type) {
1936                 case POINT_LG_MID:
1937                 case POINT_RG_MID1:
1938                 case POINT_RG_MID2:
1939                     {
1940                         SPStop *stop = sp_get_stop_i(vector, draggable->point_i);
1941                         // check if already present in list. (e.g. when both RG_MID1 and RG_MID2 were selected)
1942                         bool present = false;
1943                         for (GSList const * l = midstoplist; l != NULL; l = l->next) {
1944                             if ( (SPStop*)l->data == stop ) {
1945                                 present = true;
1946                                 break; // no need to search further.
1947                             }
1948                         }
1949                         if (!present)
1950                             midstoplist = g_slist_append(midstoplist, stop);
1951                     }
1952                     break;
1953                 case POINT_LG_BEGIN:
1954                 case POINT_LG_END:
1955                 case POINT_RG_CENTER:
1956                 case POINT_RG_R1:
1957                 case POINT_RG_R2:
1958                     {
1959                         SPStop *stop = NULL;
1960                         if ( (draggable->point_type == POINT_LG_BEGIN) || (draggable->point_type == POINT_RG_CENTER) ) {
1961                             stop = sp_first_stop(vector);
1962                         } else {
1963                             stop = sp_last_stop(vector);
1964                         }
1965                         if (stop) {
1966                             StructStopInfo *stopinfo = new StructStopInfo;
1967                             stopinfo->spstop = stop;
1968                             stopinfo->draggable = draggable;
1969                             stopinfo->gradient = gradient;
1970                             stopinfo->vector = vector;
1971                             // check if already present in list. (e.g. when both R1 and R2 were selected)
1972                             bool present = false;
1973                             for (GSList const * l = endstoplist; l != NULL; l = l->next) {
1974                                 if ( ((StructStopInfo*)l->data)->spstop == stopinfo->spstop ) {
1975                                     present = true;
1976                                     break; // no need to search further.
1977                                 }
1978                             }
1979                             if (!present)
1980                                 endstoplist = g_slist_append(endstoplist, stopinfo);
1981                         }
1982                     }
1983                     break;
1984                 default:
1985                     break;
1986             }
1987         }
1988         selected = g_list_remove(selected, dragger);
1989         if ( just_one ) break; // iterate once if just_one is set.
1990     }
1991     while (midstoplist) {
1992         SPStop *stop = (SPStop*) midstoplist->data;
1993         document = SP_OBJECT_DOCUMENT (stop);
1994         Inkscape::XML::Node * parent = SP_OBJECT_REPR(stop)->parent();
1995         parent->removeChild(SP_OBJECT_REPR(stop));
1996         midstoplist = g_slist_remove(midstoplist, stop);
1997     }
1998     while (endstoplist) {
1999         StructStopInfo *stopinfo  = (StructStopInfo*) endstoplist->data;
2000         document = SP_OBJECT_DOCUMENT (stopinfo->spstop);
2001
2002         // 2 is the minimum, cannot delete more than that without deleting the whole vector
2003         // cannot use vector->vector.stops.size() because the vector might be invalidated by deletion of a midstop
2004         // manually count the children, don't know if there already exists a function for this...
2005         int len = 0;
2006         for ( SPObject *child = sp_object_first_child(stopinfo->vector) ;
2007               child != NULL ;
2008               child = SP_OBJECT_NEXT(child) )
2009         {
2010             if ( SP_IS_STOP(child) )  len ++;
2011         }
2012         if (len > 2)
2013         {
2014             switch (stopinfo->draggable->point_type) {
2015                 case POINT_LG_BEGIN:
2016                     {
2017                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2018
2019                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
2020                         Geom::Point oldbegin = Geom::Point (lg->x1.computed, lg->y1.computed);
2021                         Geom::Point end = Geom::Point (lg->x2.computed, lg->y2.computed);
2022                         SPStop *stop = sp_first_stop(stopinfo->vector);
2023                         gdouble offset = stop->offset;
2024                         Geom::Point newbegin = oldbegin + offset * (end - oldbegin);
2025                         lg->x1.computed = newbegin[Geom::X];
2026                         lg->y1.computed = newbegin[Geom::Y];
2027
2028                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
2029                         sp_repr_set_svg_double(repr, "x1", lg->x1.computed);
2030                         sp_repr_set_svg_double(repr, "y1", lg->y1.computed);
2031                         stop->offset = 0;
2032                         sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", 0);
2033
2034                         // iterate through midstops to set new offset values such that they won't move on canvas.
2035                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2036                         stop = sp_next_stop(stop);
2037                         while ( stop != laststop ) {
2038                             stop->offset = (stop->offset - offset)/(1 - offset);
2039                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2040                             stop = sp_next_stop(stop);
2041                         }
2042                     }
2043                     break;
2044                 case POINT_LG_END:
2045                     {
2046                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2047
2048                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
2049                         Geom::Point begin = Geom::Point (lg->x1.computed, lg->y1.computed);
2050                         Geom::Point oldend = Geom::Point (lg->x2.computed, lg->y2.computed);
2051                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2052                         gdouble offset = laststop->offset;
2053                         Geom::Point newend = begin + offset * (oldend - begin);
2054                         lg->x2.computed = newend[Geom::X];
2055                         lg->y2.computed = newend[Geom::Y];
2056
2057                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
2058                         sp_repr_set_svg_double(repr, "x2", lg->x2.computed);
2059                         sp_repr_set_svg_double(repr, "y2", lg->y2.computed);
2060                         laststop->offset = 1;
2061                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
2062
2063                         // iterate through midstops to set new offset values such that they won't move on canvas.
2064                         SPStop *stop = sp_first_stop(stopinfo->vector);
2065                         stop = sp_next_stop(stop);
2066                         while ( stop != laststop ) {
2067                             stop->offset = stop->offset / offset;
2068                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2069                             stop = sp_next_stop(stop);
2070                         }
2071                     }
2072                     break;
2073                 case POINT_RG_CENTER:
2074                     {
2075                         SPStop *newfirst = sp_next_stop (stopinfo->spstop);
2076                         if (newfirst) {
2077                             newfirst->offset = 0;
2078                             sp_repr_set_css_double (SP_OBJECT_REPR (newfirst), "offset", 0);
2079                         }
2080                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2081                     }
2082                     break;
2083                 case POINT_RG_R1:
2084                 case POINT_RG_R2:
2085                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2086
2087                         SPRadialGradient *rg = SP_RADIALGRADIENT(stopinfo->gradient);
2088                         double oldradius = rg->r.computed;
2089                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2090                         gdouble offset = laststop->offset;
2091                         double newradius = offset * oldradius;
2092                         rg->r.computed = newradius;
2093
2094                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(rg);
2095                         sp_repr_set_svg_double(repr, "r", rg->r.computed);
2096                         laststop->offset = 1;
2097                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
2098
2099                         // iterate through midstops to set new offset values such that they won't move on canvas.
2100                         SPStop *stop = sp_first_stop(stopinfo->vector);
2101                         stop = sp_next_stop(stop);
2102                         while ( stop != laststop ) {
2103                             stop->offset = stop->offset / offset;
2104                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2105                             stop = sp_next_stop(stop);
2106                         }
2107                         break;
2108             }
2109         }
2110         else
2111         { // delete the gradient from the object. set fill to unset  FIXME: set to fill of unselected node?
2112             SPCSSAttr *css = sp_repr_css_attr_new ();
2113
2114             // stopinfo->spstop is the selected stop
2115             Inkscape::XML::Node *unselectedrepr = SP_OBJECT_REPR(stopinfo->vector)->firstChild();
2116             if (unselectedrepr == SP_OBJECT_REPR(stopinfo->spstop) ) {
2117                 unselectedrepr = unselectedrepr->next();
2118             }
2119
2120             if (unselectedrepr == NULL) {
2121                 if (stopinfo->draggable->fill_or_stroke) {
2122                     sp_repr_css_unset_property (css, "fill");
2123                 } else {
2124                     sp_repr_css_unset_property (css, "stroke");
2125                 }
2126             } else {
2127                 SPCSSAttr *stopcss = sp_repr_css_attr(unselectedrepr, "style");
2128                 if (stopinfo->draggable->fill_or_stroke) {
2129                     sp_repr_css_set_property(css, "fill", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
2130                     sp_repr_css_set_property(css, "fill-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
2131                 } else {
2132                     sp_repr_css_set_property(css, "stroke", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
2133                     sp_repr_css_set_property(css, "stroke-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
2134                 }
2135                 sp_repr_css_attr_unref (stopcss);
2136             }
2137
2138             sp_repr_css_change (SP_OBJECT_REPR (stopinfo->draggable->item), css, "style");
2139             sp_repr_css_attr_unref (css);
2140         }
2141
2142         endstoplist = g_slist_remove(endstoplist, stopinfo);
2143         delete stopinfo;
2144     }
2145
2146     if (document) {
2147         sp_document_done ( document, SP_VERB_CONTEXT_GRADIENT, _("Delete gradient stop(s)") );
2148     }
2149 }
2150
2151
2152 /*
2153   Local Variables:
2154   mode:c++
2155   c-file-style:"stroustrup"
2156   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
2157   indent-tabs-mode:nil
2158   fill-column:99
2159   End:
2160 */
2161 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :