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, NR::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             NR::Point begin   = sp_item_gradient_get_coords(item, POINT_LG_BEGIN, 0, fill_or_stroke);
 298             NR::Point end     = sp_item_gradient_get_coords(item, POINT_LG_END, 0, fill_or_stroke);
 299
 300             NR::Point nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 301             double dist_screen = NR::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             NR::Point begin = sp_item_gradient_get_coords(item, POINT_RG_CENTER, 0, fill_or_stroke);
 310             NR::Point end   = sp_item_gradient_get_coords(item, POINT_RG_R1, 0, fill_or_stroke);
 311             NR::Point nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 312             double dist_screen = NR::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 = NR::L2 (mouse_p - nearest);
 323             if ( dist_screen < tolerance ) {
 324                 offset = get_offset_between_points(nearest, begin, end);
 325                 addknot = true;
 326                 r1_knot = false;
 327                 break; // break out of the while loop: add only one knot
 328             }
 329         }
 330         fill_or_stroke = !fill_or_stroke;
 331     } while (!fill_or_stroke && !addknot) ;
 332
 333     if (addknot) {
 334         SPGradient *vector = sp_gradient_get_forked_vector_if_necessary (gradient, false);
 335         SPStop* prev_stop = sp_first_stop(vector);
 336         SPStop* next_stop = sp_next_stop(prev_stop);
 337         guint i = 1;
 338         while ( (next_stop) && (next_stop->offset < offset) ) {
 339             prev_stop = next_stop;
 340             next_stop = sp_next_stop(next_stop);
 341             i++;
 342         }
 343         if (!next_stop) {
 344             // logical error: the endstop should have offset 1 and should always be more than this offset here
 345             return NULL;
 346         }
 347
 348
 349         SPStop *newstop = sp_vector_add_stop (vector, prev_stop, next_stop, offset);
 350         sp_gradient_ensure_vector (gradient);
 351         updateDraggers();
 352
 353         return newstop;
 354     }
 355
 356     return NULL;
 357 }
 358
 359
 360 bool
 361 GrDrag::dropColor(SPItem */*item*/, gchar *c, NR::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 (NR::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             NR::Point nearest = snap_vector_midpoint (p, line->s, line->e, 0);
 388             double dist_screen = NR::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 void
 521 gr_knot_moved_handler(SPKnot *knot, NR::Point const *ppointer, guint state, gpointer data)
 522 {
 523     GrDragger *dragger = (GrDragger *) data;
 524     GrDrag *drag = dragger->parent;
 525
 526     NR::Point p = *ppointer;
 527
 528     // FIXME: take from prefs
 529     double snap_dist = SNAP_DIST / dragger->parent->desktop->current_zoom();
 530
 531     if (state & GDK_SHIFT_MASK) {
 532         // with Shift; unsnap if we carry more than one draggable
 533         if (dragger->draggables && dragger->draggables->next) {
 534             // create a new dragger
 535             GrDragger *dr_new = new GrDragger (dragger->parent, dragger->point, NULL);
 536             dragger->parent->draggers = g_list_prepend (dragger->parent->draggers, dr_new);
 537             // relink to it all but the first draggable in the list
 538             for (GSList const* i = dragger->draggables->next; i != NULL; i = i->next) {
 539                 GrDraggable *draggable = (GrDraggable *) i->data;
 540                 dr_new->addDraggable (draggable);
 541             }
 542             dr_new->updateKnotShape();
 543             g_slist_free (dragger->draggables->next);
 544             dragger->draggables->next = NULL;
 545             dragger->updateKnotShape();
 546             dragger->updateTip();
 547         }
 548     } else if (!(state & GDK_CONTROL_MASK)) {
 549         // without Shift or Ctrl; see if we need to snap to another dragger
 550         for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 551             GrDragger *d_new = (GrDragger *) di->data;
 552             if (dragger->mayMerge(d_new) && NR::L2 (d_new->point - p) < snap_dist) {
 553
 554                 // Merge draggers:
 555                 for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 556                     GrDraggable *draggable = (GrDraggable *) i->data;
 557                     // copy draggable to d_new:
 558                     GrDraggable *da_new = new GrDraggable (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 559                     d_new->addDraggable (da_new);
 560                 }
 561
 562                 // unlink and delete this dragger
 563                 dragger->parent->draggers = g_list_remove (dragger->parent->draggers, dragger);
 564                 delete dragger;
 565
 566                 // update the new merged dragger
 567                 d_new->fireDraggables(true, false, true);
 568                 d_new->parent->updateLines();
 569                 d_new->parent->setSelected (d_new);
 570                 d_new->updateKnotShape ();
 571                 d_new->updateTip ();
 572                 d_new->updateDependencies(true);
 573                 sp_document_done (sp_desktop_document (d_new->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 574                                   _("Merge gradient handles"));
 575                 return;
 576             }
 577         }
 578     }
 579
 580     if (!((state & GDK_SHIFT_MASK) || ((state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK)))) {
 581         // Try snapping to the grid or guides
 582         SPDesktop *desktop = dragger->parent->desktop;
 583         SnapManager &m = desktop->namedview->snap_manager;
 584         m.setup(desktop);
 585         Inkscape::SnappedPoint s = m.freeSnap(Inkscape::SnapPreferences::SNAPPOINT_NODE, to_2geom(p));
 586         if (s.getSnapped()) {
 587             p = s.getPoint();
 588             sp_knot_moveto (knot, p);
 589         } else {
 590             bool was_snapped = false;
 591             double dist = NR_HUGE;
 592             // No snapping so far, let's see if we need to snap to any of the levels
 593             for (guint i = 0; i < dragger->parent->hor_levels.size(); i++) {
 594                 dist = fabs(p[NR::Y] - dragger->parent->hor_levels[i]);
 595                 if (dist < snap_dist) {
 596                     p[NR::Y] = dragger->parent->hor_levels[i];
 597                     s = Inkscape::SnappedPoint(p, Inkscape::SNAPTARGET_GRADIENT, dist, snap_dist, false, false);
 598                     was_snapped = true;
 599                     sp_knot_moveto (knot, p);
 600                 }
 601             }
 602             for (guint i = 0; i < dragger->parent->vert_levels.size(); i++) {
 603                 dist = fabs(p[NR::X] - dragger->parent->vert_levels[i]);
 604                 if (dist < snap_dist) {
 605                     p[NR::X] = dragger->parent->vert_levels[i];
 606                     s = Inkscape::SnappedPoint(p, Inkscape::SNAPTARGET_GRADIENT, dist, snap_dist, false, false);
 607                     was_snapped = true;
 608                     sp_knot_moveto (knot, p);
 609                 }
 610             }
 611             if (was_snapped) {
 612                 desktop->snapindicator->set_new_snappoint(s);
 613             }
 614         }
 615     }
 616
 617     if (state & GDK_CONTROL_MASK) {
 618         Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 619         unsigned snaps = abs(prefs->getInt("/options/rotationsnapsperpi/value", 12));
 620         /* 0 means no snapping. */
 621
 622         // This list will store snap vectors from all draggables of dragger
 623         GSList *snap_vectors = NULL;
 624
 625         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) {
 626             GrDraggable *draggable = (GrDraggable *) i->data;
 627
 628             NR::Point *dr_snap = NULL;
 629
 630             if (draggable->point_type == POINT_LG_BEGIN || draggable->point_type == POINT_LG_END) {
 631                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 632                     GrDragger *d_new = (GrDragger *) di->data;
 633                     if (d_new == dragger)
 634                         continue;
 635                     if (d_new->isA (draggable->item,
 636                                     draggable->point_type == POINT_LG_BEGIN? POINT_LG_END : POINT_LG_BEGIN,
 637                                     draggable->fill_or_stroke)) {
 638                         // found the other end of the linear gradient;
 639                         if (state & GDK_SHIFT_MASK) {
 640                             // moving linear around center
 641                             NR::Point center = NR::Point (0.5*(d_new->point + dragger->point));
 642                             dr_snap = &center;
 643                         } else {
 644                             // moving linear around the other end
 645                             dr_snap = &d_new->point;
 646                         }
 647                     }
 648                 }
 649             } else if (draggable->point_type == POINT_RG_R1 || draggable->point_type == POINT_RG_R2 || draggable->point_type == POINT_RG_FOCUS) {
 650                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 651                     GrDragger *d_new = (GrDragger *) di->data;
 652                     if (d_new == dragger)
 653                         continue;
 654                     if (d_new->isA (draggable->item,
 655                                     POINT_RG_CENTER,
 656                                     draggable->fill_or_stroke)) {
 657                         // found the center of the radial gradient;
 658                         dr_snap = &(d_new->point);
 659                     }
 660                 }
 661             } else if (draggable->point_type == POINT_RG_CENTER) {
 662                 // radial center snaps to hor/vert relative to its original position
 663                 dr_snap = &(dragger->point_original);
 664             }
 665
 666             NR::Point *snap_vector = NULL;
 667             if (dr_snap) {
 668                 if (state & GDK_MOD1_MASK) {
 669                     // with Alt, snap to the original angle and its perpendiculars
 670                     snap_vector = get_snap_vector (p, *dr_snap, M_PI/2, NR::atan2 (dragger->point_original - *dr_snap));
 671                 } else {
 672                     // with Ctrl, snap to M_PI/snaps
 673                     snap_vector = get_snap_vector (p, *dr_snap, M_PI/snaps, 0);
 674                 }
 675             }
 676             if (snap_vector) {
 677                 snap_vectors = g_slist_prepend (snap_vectors, snap_vector);
 678             }
 679         }
 680
 681         // Move by the smallest of snap vectors:
 682         NR::Point move(9999, 9999);
 683         for (GSList const *i = snap_vectors; i != NULL; i = i->next) {
 684             NR::Point *snap_vector = (NR::Point *) i->data;
 685             if (NR::L2(*snap_vector) < NR::L2(move))
 686                 move = *snap_vector;
 687         }
 688         if (move[NR::X] < 9999) {
 689             p += move;
 690             sp_knot_moveto (knot, p);
 691         }
 692
 693         g_slist_free(snap_vectors);
 694     }
 695
 696     drag->keep_selection = (bool) g_list_find(drag->selected, dragger);
 697     bool scale_radial = (state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK);
 698
 699     if (drag->keep_selection) {
 700         NR::Point diff = p - dragger->point;
 701         drag->selected_move_nowrite (diff[NR::X], diff[NR::Y], scale_radial);
 702     } else {
 703         dragger->point = p;
 704         dragger->fireDraggables (false, scale_radial);
 705         dragger->updateDependencies(false);
 706     }
 707
 708 }
 709
 710
 711 static void
 712 gr_midpoint_limits(GrDragger *dragger, SPObject *server, NR::Point *begin, NR::Point *end, NR::Point *low_lim, NR::Point *high_lim, GSList **moving)
 713 {
 714
 715     GrDrag *drag = dragger->parent;
 716     // a midpoint dragger can (logically) only contain one GrDraggable
 717     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 718
 719     // get begin and end points between which dragging is allowed:
 720     // the draglimits are between knot(lowest_i - 1) and knot(highest_i + 1)
 721     *moving = g_slist_append(*moving, dragger);
 722
 723     guint lowest_i = draggable->point_i;
 724     guint highest_i = draggable->point_i;
 725     GrDragger *lowest_dragger = dragger;
 726     GrDragger *highest_dragger = dragger;
 727     if (dragger->isSelected()) {
 728         GrDragger* d_add;
 729         while ( true )
 730         {
 731             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 732             if ( d_add && g_list_find(drag->selected, d_add) ) {
 733                 lowest_i = lowest_i - 1;
 734                 *moving = g_slist_prepend(*moving, d_add);
 735                 lowest_dragger = d_add;
 736             } else {
 737                 break;
 738             }
 739         }
 740
 741         while ( true )
 742         {
 743             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 744             if ( d_add && g_list_find(drag->selected, d_add) ) {
 745                 highest_i = highest_i + 1;
 746                 *moving = g_slist_append(*moving, d_add);
 747                 highest_dragger = d_add;
 748             } else {
 749                 break;
 750             }
 751         }
 752     }
 753
 754     if ( SP_IS_LINEARGRADIENT(server) ) {
 755         guint num = SP_LINEARGRADIENT(server)->vector.stops.size();
 756         GrDragger *d_temp;
 757         if (lowest_i == 1) {
 758             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke);
 759         } else {
 760             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, lowest_i - 1, draggable->fill_or_stroke);
 761         }
 762         if (d_temp)
 763             *begin = d_temp->point;
 764
 765         d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, highest_i + 1, draggable->fill_or_stroke);
 766         if (d_temp == NULL) {
 767             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_END, num-1, draggable->fill_or_stroke);
 768         }
 769         if (d_temp)
 770             *end = d_temp->point;
 771     } else if ( SP_IS_RADIALGRADIENT(server) ) {
 772         guint num = SP_RADIALGRADIENT(server)->vector.stops.size();
 773         GrDragger *d_temp;
 774         if (lowest_i == 1) {
 775             d_temp = drag->getDraggerFor (draggable->item, POINT_RG_CENTER, 0, draggable->fill_or_stroke);
 776         } else {
 777             d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 778         }
 779         if (d_temp)
 780             *begin = d_temp->point;
 781
 782         d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 783         if (d_temp == NULL) {
 784             d_temp = drag->getDraggerFor (draggable->item, (draggable->point_type==POINT_RG_MID1) ? POINT_RG_R1 : POINT_RG_R2, num-1, draggable->fill_or_stroke);
 785         }
 786         if (d_temp)
 787             *end = d_temp->point;
 788     }
 789
 790     *low_lim  = dragger->point - (lowest_dragger->point - *begin);
 791     *high_lim = dragger->point - (highest_dragger->point - *end);
 792 }
 793
 794
 795
 796 /**
 797 Called when a midpoint knot is dragged.
 798 */
 799 static void
 800 gr_knot_moved_midpoint_handler(SPKnot */*knot*/, NR::Point const *ppointer, guint state, gpointer data)
 801 {
 802     GrDragger *dragger = (GrDragger *) data;
 803     GrDrag *drag = dragger->parent;
 804     // a midpoint dragger can (logically) only contain one GrDraggable
 805     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 806
 807     // FIXME: take from prefs
 808     double snap_fraction = 0.1;
 809
 810     NR::Point p = *ppointer;
 811     NR::Point begin(0,0), end(0,0);
 812     NR::Point low_lim(0,0), high_lim(0,0);
 813
 814     SPObject *server = draggable->getServer();
 815
 816     GSList *moving = NULL;
 817     gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
 818
 819     if (state & GDK_CONTROL_MASK) {
 820         p = snap_vector_midpoint (p, low_lim, high_lim, snap_fraction);
 821     } else {
 822         p = snap_vector_midpoint (p, low_lim, high_lim, 0);
 823     }
 824     NR::Point displacement = p - dragger->point;
 825
 826     for (GSList const* i = moving; i != NULL; i = i->next) {
 827         GrDragger *drg = (GrDragger*) i->data;
 828         SPKnot *drgknot = drg->knot;
 829         NR::Point this_move = displacement;
 830         if (state & GDK_MOD1_MASK) {
 831             // FIXME: unify all these profiles (here, in nodepath, in tweak) in one place
 832             double alpha = 1.0;
 833             if (NR::L2(drg->point - dragger->point) + NR::L2(drg->point - begin) - 1e-3 > NR::L2(dragger->point - begin)) { // drg is on the end side from dragger
 834                 double x = NR::L2(drg->point - dragger->point)/NR::L2(end - dragger->point);
 835                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 836             } else { // drg is on the begin side from dragger
 837                 double x = NR::L2(drg->point - dragger->point)/NR::L2(begin - dragger->point);
 838                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 839             }
 840         }
 841         drg->point += this_move;
 842         sp_knot_moveto (drgknot, drg->point);
 843         drg->fireDraggables (false);
 844         drg->updateDependencies(false);
 845     }
 846
 847     g_slist_free(moving);
 848
 849     drag->keep_selection = dragger->isSelected();
 850 }
 851
 852
 853
 854 static void
 855 gr_knot_grabbed_handler (SPKnot */*knot*/, unsigned int /*state*/, gpointer data)
 856 {
 857     GrDragger *dragger = (GrDragger *) data;
 858
 859     sp_canvas_force_full_redraw_after_interruptions(dragger->parent->desktop->canvas, 5);
 860 }
 861
 862 /**
 863 Called when the mouse releases a dragger knot; changes gradient writing to repr, updates other draggers if needed
 864 */
 865 static void
 866 gr_knot_ungrabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 867 {
 868     GrDragger *dragger = (GrDragger *) data;
 869
 870     sp_canvas_end_forced_full_redraws(dragger->parent->desktop->canvas);
 871
 872     dragger->point_original = dragger->point = knot->pos;
 873
 874     if ((state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK)) {
 875         dragger->fireDraggables (true, true);
 876     } else {
 877         dragger->fireDraggables (true);
 878     }
 879
 880     for (GList *i = dragger->parent->selected; i != NULL; i = i->next) {
 881         GrDragger *d = (GrDragger *) i->data;
 882         if (d == dragger)
 883             continue;
 884         d->fireDraggables (true);
 885     }
 886
 887     // make this dragger selected
 888     if (!dragger->parent->keep_selection) {
 889         dragger->parent->setSelected (dragger);
 890     }
 891     dragger->parent->keep_selection = false;
 892
 893     dragger->updateDependencies(true);
 894
 895     // we did an undoable action
 896     sp_document_done (sp_desktop_document (dragger->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 897                       _("Move gradient handle"));
 898 }
 899
 900 /**
 901 Called when a dragger knot is clicked; selects the dragger or deletes it depending on the
 902 state of the keyboard keys
 903 */
 904 static void
 905 gr_knot_clicked_handler(SPKnot */*knot*/, guint state, gpointer data)
 906 {
 907     GrDragger *dragger = (GrDragger *) data;
 908     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 909     if (!draggable) return;
 910
 911     if ( (state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK ) ) {
 912     // delete this knot from vector
 913         SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
 914         gradient = sp_gradient_get_vector (gradient, false);
 915         if (gradient->vector.stops.size() > 2) { // 2 is the minimum
 916                 SPStop *stop = NULL;
 917                 switch (draggable->point_type) {  // if we delete first or last stop, move the next/previous to the edge
 918                 case POINT_LG_BEGIN:
 919                 case POINT_RG_CENTER:
 920                     stop = sp_first_stop(gradient);
 921                         {
 922                             SPStop *next = sp_next_stop (stop);
 923                                 if (next) {
 924                                         next->offset = 0;
 925                                         sp_repr_set_css_double (SP_OBJECT_REPR (next), "offset", 0);
 926                                 }
 927                         }
 928                     break;
 929                 case POINT_LG_END:
 930                 case POINT_RG_R1:
 931                 case POINT_RG_R2:
 932                     stop = sp_last_stop(gradient);
 933                     {
 934                             SPStop *prev = sp_prev_stop (stop, gradient);
 935                             if (prev) {
 936                                     prev->offset = 1;
 937                                     sp_repr_set_css_double (SP_OBJECT_REPR (prev), "offset", 1);
 938                             }
 939                         }
 940                     break;
 941                 case POINT_LG_MID:
 942                 case POINT_RG_MID1:
 943                 case POINT_RG_MID2:
 944                     stop = sp_get_stop_i(gradient, draggable->point_i);
 945                     break;
 946                 }
 947
 948                 SP_OBJECT_REPR(gradient)->removeChild(SP_OBJECT_REPR(stop));
 949                 sp_document_done (SP_OBJECT_DOCUMENT (gradient), SP_VERB_CONTEXT_GRADIENT,
 950                                   _("Delete gradient stop"));
 951         }
 952     } else {
 953     // select the dragger
 954         dragger->point_original = dragger->point;
 955
 956         if ( state & GDK_SHIFT_MASK ) {
 957             dragger->parent->setSelected (dragger, true, false);
 958         } else {
 959             dragger->parent->setSelected (dragger);
 960         }
 961     }
 962 }
 963
 964 /**
 965 Called when a dragger knot is doubleclicked; opens gradient editor with the stop from the first draggable
 966 */
 967 static void
 968 gr_knot_doubleclicked_handler (SPKnot */*knot*/, guint /*state*/, gpointer data)
 969 {
 970     GrDragger *dragger = (GrDragger *) data;
 971
 972     dragger->point_original = dragger->point;
 973
 974     if (dragger->draggables == NULL)
 975         return;
 976
 977     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 978     sp_item_gradient_edit_stop (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 979 }
 980
 981 /**
 982 Act upon all draggables of the dragger, setting them to the dragger's point
 983 */
 984 void
 985 GrDragger::fireDraggables (bool write_repr, bool scale_radial, bool merging_focus)
 986 {
 987     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 988         GrDraggable *draggable = (GrDraggable *) i->data;
 989
 990         // set local_change flag so that selection_changed callback does not regenerate draggers
 991         this->parent->local_change = true;
 992
 993         // change gradient, optionally writing to repr; prevent focus from moving if it's snapped
 994         // to the center, unless it's the first update upon merge when we must snap it to the point
 995         if (merging_focus ||
 996             !(draggable->point_type == POINT_RG_FOCUS && this->isA(draggable->item, POINT_RG_CENTER, draggable->point_i, draggable->fill_or_stroke)))
 997         {
 998             sp_item_gradient_set_coords (draggable->item, draggable->point_type, draggable->point_i, this->point, draggable->fill_or_stroke, write_repr, scale_radial);
 999         }
1000     }
1001 }
1002
1003 /**
1004 Checks if the dragger has a draggable with this point_type
1005  */
1006 bool
1007 GrDragger::isA (gint point_type)
1008 {
1009     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1010         GrDraggable *draggable = (GrDraggable *) i->data;
1011         if (draggable->point_type == point_type) {
1012             return true;
1013         }
1014     }
1015     return false;
1016 }
1017
1018 /**
1019 Checks if the dragger has a draggable with this item, point_type + point_i (number), fill_or_stroke
1020  */
1021 bool
1022 GrDragger::isA (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
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) && (draggable->point_i == point_i) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
1027             return true;
1028         }
1029     }
1030     return false;
1031 }
1032
1033 /**
1034 Checks if the dragger has a draggable with this item, point_type, fill_or_stroke
1035  */
1036 bool
1037 GrDragger::isA (SPItem *item, gint point_type, 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->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
1042             return true;
1043         }
1044     }
1045     return false;
1046 }
1047
1048 bool
1049 GrDraggable::mayMerge (GrDraggable *da2)
1050 {
1051     if ((this->item == da2->item) && (this->fill_or_stroke == da2->fill_or_stroke)) {
1052         // we must not merge the points of the same gradient!
1053         if (!((this->point_type == POINT_RG_FOCUS && da2->point_type == POINT_RG_CENTER) ||
1054               (this->point_type == POINT_RG_CENTER && da2->point_type == POINT_RG_FOCUS))) {
1055             // except that we can snap center and focus together
1056             return false;
1057         }
1058     }
1059     // disable merging of midpoints.
1060     if ( (this->point_type == POINT_LG_MID) || (da2->point_type == POINT_LG_MID)
1061          || (this->point_type == POINT_RG_MID1) || (da2->point_type == POINT_RG_MID1)
1062          || (this->point_type == POINT_RG_MID2) || (da2->point_type == POINT_RG_MID2) )
1063         return false;
1064
1065     return true;
1066 }
1067
1068 bool
1069 GrDragger::mayMerge (GrDragger *other)
1070 {
1071     if (this == other)
1072         return false;
1073
1074     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
1075         GrDraggable *da1 = (GrDraggable *) i->data;
1076         for (GSList const* j = other->draggables; j != NULL; j = j->next) { // for all draggables of other
1077             GrDraggable *da2 = (GrDraggable *) j->data;
1078             if (!da1->mayMerge(da2))
1079                 return false;
1080         }
1081     }
1082     return true;
1083 }
1084
1085 bool
1086 GrDragger::mayMerge (GrDraggable *da2)
1087 {
1088     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
1089         GrDraggable *da1 = (GrDraggable *) i->data;
1090         if (!da1->mayMerge(da2))
1091             return false;
1092     }
1093     return true;
1094 }
1095
1096 /**
1097 Updates the statusbar tip of the dragger knot, based on its draggables
1098  */
1099 void
1100 GrDragger::updateTip ()
1101 {
1102         if (this->knot && this->knot->tip) {
1103                 g_free (this->knot->tip);
1104                 this->knot->tip = NULL;
1105         }
1106
1107     if (g_slist_length (this->draggables) == 1) {
1108         GrDraggable *draggable = (GrDraggable *) this->draggables->data;
1109         char *item_desc = sp_item_description(draggable->item);
1110         switch (draggable->point_type) {
1111             case POINT_LG_MID:
1112             case POINT_RG_MID1:
1113             case POINT_RG_MID2:
1114                 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"),
1115                                                    _(gr_knot_descr[draggable->point_type]),
1116                                                    draggable->point_i,
1117                                                    item_desc,
1118                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
1119                 break;
1120
1121             default:
1122                 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"),
1123                                                    _(gr_knot_descr[draggable->point_type]),
1124                                                    item_desc,
1125                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
1126                 break;
1127         }
1128         g_free(item_desc);
1129     } else if (g_slist_length (draggables) == 2 && isA (POINT_RG_CENTER) && isA (POINT_RG_FOCUS)) {
1130         this->knot->tip = g_strdup_printf (_("Radial gradient <b>center</b> and <b>focus</b>; drag with <b>Shift</b> to separate focus"));
1131     } else {
1132         int length = g_slist_length (this->draggables);
1133         this->knot->tip = g_strdup_printf (ngettext("Gradient point shared by <b>%d</b> gradient; drag with <b>Shift</b> to separate",
1134                                                     "Gradient point shared by <b>%d</b> gradients; drag with <b>Shift</b> to separate",
1135                                                     length),
1136                                            length);
1137     }
1138 }
1139
1140 /**
1141 Adds a draggable to the dragger
1142  */
1143 void
1144 GrDragger::updateKnotShape ()
1145 {
1146     if (!draggables)
1147         return;
1148     GrDraggable *last = (GrDraggable *) g_slist_last(draggables)->data;
1149     g_object_set (G_OBJECT (this->knot->item), "shape", gr_knot_shapes[last->point_type], NULL);
1150 }
1151
1152 /**
1153 Adds a draggable to the dragger
1154  */
1155 void
1156 GrDragger::addDraggable (GrDraggable *draggable)
1157 {
1158     this->draggables = g_slist_prepend (this->draggables, draggable);
1159
1160     this->updateTip();
1161 }
1162
1163
1164 /**
1165 Moves this dragger to the point of the given draggable, acting upon all other draggables
1166  */
1167 void
1168 GrDragger::moveThisToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1169 {
1170     this->point = sp_item_gradient_get_coords (item, point_type, point_i, fill_or_stroke);
1171     this->point_original = this->point;
1172
1173     sp_knot_moveto (this->knot, this->point);
1174
1175     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1176         GrDraggable *da = (GrDraggable *) i->data;
1177         if ( (da->item == item) &&
1178              (point_type == -1 || da->point_type == point_type) &&
1179              (point_i == -1 || da->point_i == point_i) &&
1180              (da->fill_or_stroke == fill_or_stroke) ) {
1181             continue;
1182         }
1183         sp_item_gradient_set_coords (da->item, da->point_type, da->point_i, this->point, da->fill_or_stroke, write_repr, false);
1184     }
1185     // FIXME: here we should also call this->updateDependencies(write_repr); to propagate updating, but how to prevent loops?
1186 }
1187
1188
1189 /**
1190 Moves all midstop draggables that depend on this one
1191  */
1192 void
1193 GrDragger::updateMidstopDependencies (GrDraggable *draggable, bool write_repr) {
1194     SPObject *server = draggable->getServer();
1195     if (!server)
1196         return;
1197     guint num = SP_GRADIENT(server)->vector.stops.size();
1198     if (num <= 2) return;
1199
1200     if ( SP_IS_LINEARGRADIENT(server) ) {
1201         for ( guint i = 1; i < num - 1; i++ ) {
1202             this->moveOtherToDraggable (draggable->item, POINT_LG_MID, i, draggable->fill_or_stroke, write_repr);
1203         }
1204     } else  if ( SP_IS_RADIALGRADIENT(server) ) {
1205         for ( guint i = 1; i < num - 1; i++ ) {
1206             this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, i, draggable->fill_or_stroke, write_repr);
1207             this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, i, draggable->fill_or_stroke, write_repr);
1208         }
1209     }
1210 }
1211
1212
1213 /**
1214 Moves all draggables that depend on this one
1215  */
1216 void
1217 GrDragger::updateDependencies (bool write_repr)
1218 {
1219     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1220         GrDraggable *draggable = (GrDraggable *) i->data;
1221         switch (draggable->point_type) {
1222             case POINT_LG_BEGIN:
1223                 {
1224                     // the end point is dependent only when dragging with ctrl+shift
1225                     this->moveOtherToDraggable (draggable->item, POINT_LG_END, -1, draggable->fill_or_stroke, write_repr);
1226
1227                     this->updateMidstopDependencies (draggable, write_repr);
1228                 }
1229                 break;
1230             case POINT_LG_END:
1231                 {
1232                     // the begin point is dependent only when dragging with ctrl+shift
1233                     this->moveOtherToDraggable (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke, write_repr);
1234
1235                     this->updateMidstopDependencies (draggable, write_repr);
1236                 }
1237                 break;
1238             case POINT_LG_MID:
1239                 // no other nodes depend on mid points.
1240                 break;
1241             case POINT_RG_R2:
1242                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1243                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1244                 this->updateMidstopDependencies (draggable, write_repr);
1245                 break;
1246             case POINT_RG_R1:
1247                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1248                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1249                 this->updateMidstopDependencies (draggable, write_repr);
1250                 break;
1251             case POINT_RG_CENTER:
1252                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1253                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1254                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1255                 this->updateMidstopDependencies (draggable, write_repr);
1256                 break;
1257             case POINT_RG_FOCUS:
1258                 // nothing can depend on that
1259                 break;
1260             case POINT_RG_MID1:
1261                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, draggable->point_i, draggable->fill_or_stroke, write_repr);
1262                 break;
1263             case POINT_RG_MID2:
1264                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, draggable->point_i, draggable->fill_or_stroke, write_repr);
1265                 break;
1266             default:
1267                 break;
1268         }
1269     }
1270 }
1271
1272
1273
1274 GrDragger::GrDragger (GrDrag *parent, NR::Point p, GrDraggable *draggable)
1275 {
1276     this->draggables = NULL;
1277
1278     this->parent = parent;
1279
1280     this->point = p;
1281     this->point_original = p;
1282
1283     // create the knot
1284     this->knot = sp_knot_new (parent->desktop, NULL);
1285     this->knot->setMode(SP_KNOT_MODE_XOR);
1286     this->knot->setFill(GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_MOUSEOVER, GR_KNOT_COLOR_MOUSEOVER);
1287     this->knot->setStroke(0x0000007f, 0x0000007f, 0x0000007f);
1288     sp_knot_update_ctrl(this->knot);
1289
1290     // move knot to the given point
1291     sp_knot_set_position (this->knot, p, SP_KNOT_STATE_NORMAL);
1292     sp_knot_show (this->knot);
1293
1294     // connect knot's signals
1295     if ( (draggable)  // it can be NULL if a node in unsnapped (eg. focus point unsnapped from center)
1296                        // luckily, midstops never snap to other nodes so are never unsnapped...
1297          && ( (draggable->point_type == POINT_LG_MID)
1298               || (draggable->point_type == POINT_RG_MID1)
1299               || (draggable->point_type == POINT_RG_MID2) ) )
1300     {
1301         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_midpoint_handler), this);
1302     } else {
1303         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_handler), this);
1304     }
1305     g_signal_connect (G_OBJECT (this->knot), "clicked", G_CALLBACK (gr_knot_clicked_handler), this);
1306     g_signal_connect (G_OBJECT (this->knot), "doubleclicked", G_CALLBACK (gr_knot_doubleclicked_handler), this);
1307     g_signal_connect (G_OBJECT (this->knot), "grabbed", G_CALLBACK (gr_knot_grabbed_handler), this);
1308     g_signal_connect (G_OBJECT (this->knot), "ungrabbed", G_CALLBACK (gr_knot_ungrabbed_handler), this);
1309
1310     // add the initial draggable
1311     if (draggable)
1312         this->addDraggable (draggable);
1313     updateKnotShape();
1314 }
1315
1316 GrDragger::~GrDragger ()
1317 {
1318     // unselect if it was selected
1319     this->parent->setDeselected(this);
1320
1321     // disconnect signals
1322     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_moved_handler), this);
1323     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_clicked_handler), this);
1324     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_doubleclicked_handler), this);
1325     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_grabbed_handler), this);
1326     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_ungrabbed_handler), this);
1327
1328     /* unref should call destroy */
1329     g_object_unref (G_OBJECT (this->knot));
1330
1331     // delete all draggables
1332     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1333         delete ((GrDraggable *) i->data);
1334     }
1335     g_slist_free (this->draggables);
1336     this->draggables = NULL;
1337 }
1338
1339 /**
1340 Select the dragger which has the given draggable.
1341 */
1342 GrDragger *
1343 GrDrag::getDraggerFor (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1344 {
1345     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1346         GrDragger *dragger = (GrDragger *) i->data;
1347         for (GSList const* j = dragger->draggables; j != NULL; j = j->next) {
1348             GrDraggable *da2 = (GrDraggable *) j->data;
1349             if ( (da2->item == item) &&
1350                  (point_type == -1 || da2->point_type == point_type) && // -1 means this does not matter
1351                  (point_i == -1 || da2->point_i == point_i) && // -1 means this does not matter
1352                  (da2->fill_or_stroke == fill_or_stroke)) {
1353                 return (dragger);
1354             }
1355         }
1356     }
1357     return NULL;
1358 }
1359
1360
1361 void
1362 GrDragger::moveOtherToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1363 {
1364     GrDragger *d = this->parent->getDraggerFor (item, point_type, point_i, fill_or_stroke);
1365     if (d && d !=  this) {
1366         d->moveThisToDraggable (item, point_type, point_i, fill_or_stroke, write_repr);
1367     }
1368 }
1369
1370
1371 /**
1372   Draw this dragger as selected
1373 */
1374 void
1375 GrDragger::select()
1376 {
1377     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_SELECTED;
1378     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_SELECTED, NULL);
1379 }
1380
1381 /**
1382   Draw this dragger as normal (deselected)
1383 */
1384 void
1385 GrDragger::deselect()
1386 {
1387     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_NORMAL;
1388     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_NORMAL, NULL);
1389 }
1390
1391 bool
1392 GrDragger::isSelected()
1393 {
1394     return g_list_find (parent->selected, this);
1395 }
1396
1397 /**
1398 \brief Deselect all stops/draggers (private)
1399 */
1400 void
1401 GrDrag::deselect_all()
1402 {
1403     while (selected) {
1404         ( (GrDragger*) selected->data)->deselect();
1405         selected = g_list_remove(selected, selected->data);
1406     }
1407 }
1408
1409 /**
1410 \brief Deselect all stops/draggers (public; emits signal)
1411 */
1412 void
1413 GrDrag::deselectAll()
1414 {
1415     deselect_all();
1416     this->desktop->emitToolSubselectionChanged(NULL);
1417 }
1418
1419 /**
1420 \brief Select all stops/draggers
1421 */
1422 void
1423 GrDrag::selectAll()
1424 {
1425     for (GList *l = this->draggers; l != NULL; l = l->next) {
1426         GrDragger *d = ((GrDragger *) l->data);
1427         setSelected (d, true, true);
1428     }
1429 }
1430
1431 /**
1432 \brief Select all stops/draggers that match the coords
1433 */
1434 void
1435 GrDrag::selectByCoords(std::vector<NR::Point> coords)
1436 {
1437     for (GList *l = this->draggers; l != NULL; l = l->next) {
1438         GrDragger *d = ((GrDragger *) l->data);
1439         for (guint k = 0; k < coords.size(); k++) {
1440             if (NR::L2 (d->point - coords[k]) < 1e-4) {
1441                 setSelected (d, true, true);
1442             }
1443         }
1444     }
1445 }
1446
1447
1448 /**
1449 \brief Select all stops/draggers that fall within the rect
1450 */
1451 void
1452 GrDrag::selectRect(Geom::Rect const &r)
1453 {
1454     for (GList *l = this->draggers; l != NULL; l = l->next) {
1455         GrDragger *d = ((GrDragger *) l->data);
1456         if (r.contains(d->point)) {
1457            setSelected (d, true, true);
1458         }
1459     }
1460 }
1461
1462 /**
1463 \brief Select a dragger
1464 \param dragger       The dragger to select
1465 \param add_to_selection   If true, add to selection, otherwise deselect others
1466 \param override      If true, always select this node, otherwise toggle selected status
1467 */
1468 void
1469 GrDrag::setSelected (GrDragger *dragger, bool add_to_selection, bool override)
1470 {
1471     GrDragger *seldragger = NULL;
1472
1473     if (add_to_selection) {
1474         if (!dragger) return;
1475         if (override) {
1476             if (!g_list_find(selected, dragger)) {
1477                 selected = g_list_prepend(selected, dragger);
1478             }
1479             dragger->select();
1480             seldragger = dragger;
1481         } else { // toggle
1482             if (g_list_find(selected, dragger)) {
1483                 selected = g_list_remove(selected, dragger);
1484                 dragger->deselect();
1485                 if (selected) {
1486                     seldragger = (GrDragger*) selected->data; // select the dragger that is first in the list
1487                 }
1488             } else {
1489                 selected = g_list_prepend(selected, dragger);
1490                 dragger->select();
1491                 seldragger = dragger;
1492             }
1493         }
1494     } else {
1495         deselect_all();
1496         if (dragger) {
1497             selected = g_list_prepend(selected, dragger);
1498             dragger->select();
1499             seldragger = dragger;
1500         }
1501     }
1502     if (seldragger) {
1503         this->desktop->emitToolSubselectionChanged((gpointer) seldragger);
1504     }
1505 }
1506
1507 /**
1508 \brief Deselect a dragger
1509 \param dragger       The dragger to deselect
1510 */
1511 void
1512 GrDrag::setDeselected (GrDragger *dragger)
1513 {
1514     if (g_list_find(selected, dragger)) {
1515         selected = g_list_remove(selected, dragger);
1516         dragger->deselect();
1517     }
1518     this->desktop->emitToolSubselectionChanged((gpointer) (selected ? selected->data : NULL ));
1519 }
1520
1521
1522
1523 /**
1524 Create a line from p1 to p2 and add it to the lines list
1525  */
1526 void
1527 GrDrag::addLine (SPItem *item, NR::Point p1, NR::Point p2, guint32 rgba)
1528 {
1529     SPCanvasItem *line = sp_canvas_item_new(sp_desktop_controls(this->desktop),
1530                                                             SP_TYPE_CTRLLINE, NULL);
1531     sp_canvas_item_move_to_z(line, 0);
1532     SP_CTRLLINE(line)->item = item;
1533     sp_ctrlline_set_coords(SP_CTRLLINE(line), p1, p2);
1534     if (rgba != GR_LINE_COLOR_FILL) // fill is the default, so don't set color for it to speed up redraw
1535         sp_ctrlline_set_rgba32 (SP_CTRLLINE(line), rgba);
1536     sp_canvas_item_show (line);
1537     this->lines = g_slist_append (this->lines, line);
1538 }
1539
1540 /**
1541 If there already exists a dragger within MERGE_DIST of p, add the draggable to it; otherwise create
1542 new dragger and add it to draggers list
1543  */
1544 void
1545 GrDrag::addDragger (GrDraggable *draggable)
1546 {
1547     NR::Point p = sp_item_gradient_get_coords (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
1548
1549     for (GList *i = this->draggers; i != NULL; i = i->next) {
1550         GrDragger *dragger = (GrDragger *) i->data;
1551         if (dragger->mayMerge (draggable) && NR::L2 (dragger->point - p) < MERGE_DIST) {
1552             // distance is small, merge this draggable into dragger, no need to create new dragger
1553             dragger->addDraggable (draggable);
1554             dragger->updateKnotShape();
1555             return;
1556         }
1557     }
1558
1559     GrDragger *new_dragger = new GrDragger(this, p, draggable);
1560     // fixme: draggers should be added AFTER the last one: this way tabbing through them will be from begin to end.
1561     this->draggers = g_list_append (this->draggers, new_dragger);
1562 }
1563
1564 /**
1565 Add draggers for the radial gradient rg on item
1566 */
1567 void
1568 GrDrag::addDraggersRadial (SPRadialGradient *rg, SPItem *item, bool fill_or_stroke)
1569 {
1570     addDragger (new GrDraggable (item, POINT_RG_CENTER, 0, fill_or_stroke));
1571     guint num = rg->vector.stops.size();
1572     if (num > 2) {
1573         for ( guint i = 1; i < num - 1; i++ ) {
1574             addDragger (new GrDraggable (item, POINT_RG_MID1, i, fill_or_stroke));
1575         }
1576     }
1577     addDragger (new GrDraggable (item, POINT_RG_R1, num-1, fill_or_stroke));
1578     if (num > 2) {
1579         for ( guint i = 1; i < num - 1; i++ ) {
1580             addDragger (new GrDraggable (item, POINT_RG_MID2, i, fill_or_stroke));
1581         }
1582     }
1583     addDragger (new GrDraggable (item, POINT_RG_R2, num-1, fill_or_stroke));
1584     addDragger (new GrDraggable (item, POINT_RG_FOCUS, 0, fill_or_stroke));
1585 }
1586
1587 /**
1588 Add draggers for the linear gradient lg on item
1589 */
1590 void
1591 GrDrag::addDraggersLinear (SPLinearGradient *lg, SPItem *item, bool fill_or_stroke)
1592 {
1593     addDragger (new GrDraggable (item, POINT_LG_BEGIN, 0, fill_or_stroke));
1594     guint num = lg->vector.stops.size();
1595     if (num > 2) {
1596         for ( guint i = 1; i < num - 1; i++ ) {
1597             addDragger (new GrDraggable (item, POINT_LG_MID, i, fill_or_stroke));
1598         }
1599     }
1600     addDragger (new GrDraggable (item, POINT_LG_END, num-1, fill_or_stroke));
1601 }
1602
1603 /**
1604 Artificially grab the knot of this dragger; used by the gradient context
1605 */
1606 void
1607 GrDrag::grabKnot (GrDragger *dragger, gint x, gint y, guint32 etime)
1608 {
1609     if (dragger) {
1610         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1611     }
1612 }
1613
1614 /**
1615 Artificially grab the knot of the dragger with this draggable; used by the gradient context
1616 */
1617 void
1618 GrDrag::grabKnot (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, gint x, gint y, guint32 etime)
1619 {
1620     GrDragger *dragger = getDraggerFor (item, point_type, point_i, fill_or_stroke);
1621     if (dragger) {
1622         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1623     }
1624 }
1625
1626 /**
1627 Regenerates the draggers list from the current selection; is called when selection is changed or
1628 modified, also when a radial dragger needs to update positions of other draggers in the gradient
1629 */
1630 void
1631 GrDrag::updateDraggers ()
1632 {
1633     while (selected) {
1634         selected = g_list_remove(selected, selected->data);
1635     }
1636     // delete old draggers
1637     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1638         delete ((GrDragger *) i->data);
1639     }
1640     g_list_free (this->draggers);
1641     this->draggers = NULL;
1642
1643     g_return_if_fail (this->selection != NULL);
1644
1645     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1646
1647         SPItem *item = SP_ITEM(i->data);
1648         SPStyle *style = SP_OBJECT_STYLE (item);
1649
1650         if (style && (style->fill.isPaintserver())) {
1651             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1652             if (SP_IS_LINEARGRADIENT (server)) {
1653                 addDraggersLinear (SP_LINEARGRADIENT (server), item, true);
1654             } else if (SP_IS_RADIALGRADIENT (server)) {
1655                 addDraggersRadial (SP_RADIALGRADIENT (server), item, true);
1656             }
1657         }
1658
1659         if (style && (style->stroke.isPaintserver())) {
1660             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1661             if (SP_IS_LINEARGRADIENT (server)) {
1662                 addDraggersLinear (SP_LINEARGRADIENT (server), item, false);
1663             } else if (SP_IS_RADIALGRADIENT (server)) {
1664                 addDraggersRadial (SP_RADIALGRADIENT (server), item, false);
1665             }
1666         }
1667     }
1668 }
1669
1670 /**
1671 Regenerates the lines list from the current selection; is called on each move of a dragger, so that
1672 lines are always in sync with the actual gradient
1673 */
1674 void
1675 GrDrag::updateLines ()
1676 {
1677     // delete old lines
1678     for (GSList const *i = this->lines; i != NULL; i = i->next) {
1679         gtk_object_destroy( GTK_OBJECT (i->data));
1680     }
1681     g_slist_free (this->lines);
1682     this->lines = NULL;
1683
1684     g_return_if_fail (this->selection != NULL);
1685
1686     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1687
1688         SPItem *item = SP_ITEM(i->data);
1689
1690         SPStyle *style = SP_OBJECT_STYLE (item);
1691
1692         if (style && (style->fill.isPaintserver())) {
1693             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1694             if (SP_IS_LINEARGRADIENT (server)) {
1695                 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);
1696             } else if (SP_IS_RADIALGRADIENT (server)) {
1697                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, true);
1698                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, true), GR_LINE_COLOR_FILL);
1699                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, true), GR_LINE_COLOR_FILL);
1700             }
1701         }
1702
1703         if (style && (style->stroke.isPaintserver())) {
1704             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1705             if (SP_IS_LINEARGRADIENT (server)) {
1706                 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);
1707             } else if (SP_IS_RADIALGRADIENT (server)) {
1708                 NR::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, false);
1709                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, false), GR_LINE_COLOR_STROKE);
1710                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, false), GR_LINE_COLOR_STROKE);
1711             }
1712         }
1713     }
1714 }
1715
1716 /**
1717 Regenerates the levels list from the current selection
1718 */
1719 void
1720 GrDrag::updateLevels ()
1721 {
1722     hor_levels.clear();
1723     vert_levels.clear();
1724
1725     g_return_if_fail (this->selection != NULL);
1726
1727     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1728         SPItem *item = SP_ITEM(i->data);
1729         boost::optional<Geom::Rect> rect = sp_item_bbox_desktop (item);
1730         if (rect) {
1731             // Remember the edges of the bbox and the center axis
1732             hor_levels.push_back(rect->min()[Geom::Y]);
1733             hor_levels.push_back(rect->max()[Geom::Y]);
1734             hor_levels.push_back(0.5 * (rect->min()[Geom::Y] + rect->max()[Geom::Y]));
1735             vert_levels.push_back(rect->min()[Geom::X]);
1736             vert_levels.push_back(rect->max()[Geom::X]);
1737             vert_levels.push_back(0.5 * (rect->min()[Geom::X] + rect->max()[Geom::X]));
1738         }
1739     }
1740 }
1741
1742 void
1743 GrDrag::selected_reverse_vector ()
1744 {
1745     if (selected == NULL)
1746         return;
1747
1748     for (GSList const* i = ( (GrDragger*) selected->data )->draggables; i != NULL; i = i->next) {
1749         GrDraggable *draggable = (GrDraggable *) i->data;
1750
1751         sp_item_gradient_reverse_vector (draggable->item, draggable->fill_or_stroke);
1752     }
1753 }
1754
1755 void
1756 GrDrag::selected_move_nowrite (double x, double y, bool scale_radial)
1757 {
1758     selected_move (x, y, false, scale_radial);
1759 }
1760
1761 void
1762 GrDrag::selected_move (double x, double y, bool write_repr, bool scale_radial)
1763 {
1764     if (selected == NULL)
1765         return;
1766
1767     bool did = false;
1768
1769     for (GList *i = selected; i != NULL; i = i->next) {
1770         GrDragger *d = (GrDragger *) i->data;
1771
1772         if (!d->isA(POINT_LG_MID) && !d->isA(POINT_RG_MID1) && !d->isA(POINT_RG_MID2)) {
1773             // if this is an endpoint,
1774
1775             // Moving an rg center moves its focus and radii as well.
1776             // therefore, if this is a focus or radius and if selection
1777             // contains the center as well, do not move this one
1778             if (d->isA(POINT_RG_R1) || d->isA(POINT_RG_R2) ||
1779                 (d->isA(POINT_RG_FOCUS) && !d->isA(POINT_RG_CENTER))) {
1780                 bool skip_radius_with_center = false;
1781                 for (GList *di = selected; di != NULL; di = di->next) {
1782                     GrDragger *d_new = (GrDragger *) di->data;
1783                     if (d_new->isA (((GrDraggable *) d->draggables->data)->item,
1784                                     POINT_RG_CENTER,
1785                                     0,
1786                                     ((GrDraggable *) d->draggables->data)->fill_or_stroke)) {
1787                         // FIXME: here we take into account only the first draggable!
1788                         skip_radius_with_center = true;
1789                     }
1790                 }
1791                 if (skip_radius_with_center)
1792                     continue;
1793             }
1794
1795             did = true;
1796             d->point += NR::Point (x, y);
1797             d->point_original = d->point;
1798             sp_knot_moveto (d->knot, d->point);
1799
1800             d->fireDraggables (write_repr, scale_radial);
1801
1802             d->updateDependencies(write_repr);
1803         }
1804     }
1805
1806     if (write_repr && did) {
1807         // we did an undoable action
1808         sp_document_maybe_done (sp_desktop_document (desktop), "grmoveh", SP_VERB_CONTEXT_GRADIENT,
1809                                 _("Move gradient handle(s)"));
1810         return;
1811     }
1812
1813     if (!did) { // none of the end draggers are selected, so let's try to move the mids
1814
1815         GrDragger *dragger = (GrDragger *) selected->data;
1816         // a midpoint dragger can (logically) only contain one GrDraggable
1817         GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
1818
1819         NR::Point begin(0,0), end(0,0);
1820         NR::Point low_lim(0,0), high_lim(0,0);
1821
1822         SPObject *server = draggable->getServer();
1823         GSList *moving = NULL;
1824         gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
1825
1826         NR::Point p(x, y);
1827         p = snap_vector_midpoint (dragger->point + p, low_lim, high_lim, 0);
1828         NR::Point displacement = p - dragger->point;
1829
1830         for (GSList const* i = moving; i != NULL; i = i->next) {
1831             GrDragger *drg = (GrDragger*) i->data;
1832             SPKnot *drgknot = drg->knot;
1833             drg->point += displacement;
1834             sp_knot_moveto (drgknot, drg->point);
1835             drg->fireDraggables (true);
1836             drg->updateDependencies(true);
1837             did = true;
1838         }
1839
1840         g_slist_free(moving);
1841
1842         if (write_repr && did) {
1843             // we did an undoable action
1844             sp_document_maybe_done (sp_desktop_document (desktop), "grmovem", SP_VERB_CONTEXT_GRADIENT,
1845                                     _("Move gradient mid stop(s)"));
1846         }
1847     }
1848 }
1849
1850 void
1851 GrDrag::selected_move_screen (double x, double y)
1852 {
1853     gdouble zoom = desktop->current_zoom();
1854     gdouble zx = x / zoom;
1855     gdouble zy = y / zoom;
1856
1857     selected_move (zx, zy);
1858 }
1859
1860 /**
1861 Select the knot next to the last selected one and deselect all other selected.
1862 */
1863 GrDragger *
1864 GrDrag::select_next ()
1865 {
1866     GrDragger *d = NULL;
1867     if (selected == NULL || g_list_find(draggers, selected->data)->next == NULL) {
1868         if (draggers)
1869             d = (GrDragger *) draggers->data;
1870     } else {
1871         d = (GrDragger *) g_list_find(draggers, selected->data)->next->data;
1872     }
1873     if (d)
1874         setSelected (d);
1875     return d;
1876 }
1877
1878 /**
1879 Select the knot previous from the last selected one and deselect all other selected.
1880 */
1881 GrDragger *
1882 GrDrag::select_prev ()
1883 {
1884     GrDragger *d = NULL;
1885     if (selected == NULL || g_list_find(draggers, selected->data)->prev == NULL) {
1886         if (draggers)
1887             d = (GrDragger *) g_list_last (draggers)->data;
1888     } else {
1889         d = (GrDragger *) g_list_find(draggers, selected->data)->prev->data;
1890     }
1891     if (d)
1892         setSelected (d);
1893     return d;
1894 }
1895
1896
1897 // FIXME: i.m.o. an ugly function that I just made to work, but... aargh! (Johan)
1898 void
1899 GrDrag::deleteSelected (bool just_one)
1900 {
1901     if (!selected) return;
1902
1903     SPDocument *document = false;
1904
1905     struct StructStopInfo {
1906         SPStop * spstop;
1907         GrDraggable * draggable;
1908         SPGradient * gradient;
1909         SPGradient * vector;
1910     };
1911
1912     GSList *midstoplist = NULL;  // list of stops that must be deleted (will be deleted first)
1913     GSList *endstoplist = NULL;  // list of stops that must be deleted
1914     while (selected) {
1915         GrDragger *dragger = (GrDragger*) selected->data;
1916         for (GSList * drgble = dragger->draggables; drgble != NULL; drgble = drgble->next) {
1917             GrDraggable *draggable = (GrDraggable*) drgble->data;
1918             SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
1919             SPGradient *vector   = sp_gradient_get_forked_vector_if_necessary (gradient, false);
1920
1921             switch (draggable->point_type) {
1922                 case POINT_LG_MID:
1923                 case POINT_RG_MID1:
1924                 case POINT_RG_MID2:
1925                     {
1926                         SPStop *stop = sp_get_stop_i(vector, draggable->point_i);
1927                         // check if already present in list. (e.g. when both RG_MID1 and RG_MID2 were selected)
1928                         bool present = false;
1929                         for (GSList const * l = midstoplist; l != NULL; l = l->next) {
1930                             if ( (SPStop*)l->data == stop ) {
1931                                 present = true;
1932                                 break; // no need to search further.
1933                             }
1934                         }
1935                         if (!present)
1936                             midstoplist = g_slist_append(midstoplist, stop);
1937                     }
1938                     break;
1939                 case POINT_LG_BEGIN:
1940                 case POINT_LG_END:
1941                 case POINT_RG_CENTER:
1942                 case POINT_RG_R1:
1943                 case POINT_RG_R2:
1944                     {
1945                         SPStop *stop = NULL;
1946                         if ( (draggable->point_type == POINT_LG_BEGIN) || (draggable->point_type == POINT_RG_CENTER) ) {
1947                             stop = sp_first_stop(vector);
1948                         } else {
1949                             stop = sp_last_stop(vector);
1950                         }
1951                         if (stop) {
1952                             StructStopInfo *stopinfo = new StructStopInfo;
1953                             stopinfo->spstop = stop;
1954                             stopinfo->draggable = draggable;
1955                             stopinfo->gradient = gradient;
1956                             stopinfo->vector = vector;
1957                             // check if already present in list. (e.g. when both R1 and R2 were selected)
1958                             bool present = false;
1959                             for (GSList const * l = endstoplist; l != NULL; l = l->next) {
1960                                 if ( ((StructStopInfo*)l->data)->spstop == stopinfo->spstop ) {
1961                                     present = true;
1962                                     break; // no need to search further.
1963                                 }
1964                             }
1965                             if (!present)
1966                                 endstoplist = g_slist_append(endstoplist, stopinfo);
1967                         }
1968                     }
1969                     break;
1970                 default:
1971                     break;
1972             }
1973         }
1974         selected = g_list_remove(selected, dragger);
1975         if ( just_one ) break; // iterate once if just_one is set.
1976     }
1977     while (midstoplist) {
1978         SPStop *stop = (SPStop*) midstoplist->data;
1979         document = SP_OBJECT_DOCUMENT (stop);
1980         Inkscape::XML::Node * parent = SP_OBJECT_REPR(stop)->parent();
1981         parent->removeChild(SP_OBJECT_REPR(stop));
1982         midstoplist = g_slist_remove(midstoplist, stop);
1983     }
1984     while (endstoplist) {
1985         StructStopInfo *stopinfo  = (StructStopInfo*) endstoplist->data;
1986         document = SP_OBJECT_DOCUMENT (stopinfo->spstop);
1987
1988         // 2 is the minimum, cannot delete more than that without deleting the whole vector
1989         // cannot use vector->vector.stops.size() because the vector might be invalidated by deletion of a midstop
1990         // manually count the children, don't know if there already exists a function for this...
1991         int len = 0;
1992         for ( SPObject *child = sp_object_first_child(stopinfo->vector) ;
1993               child != NULL ;
1994               child = SP_OBJECT_NEXT(child) )
1995         {
1996             if ( SP_IS_STOP(child) )  len ++;
1997         }
1998         if (len > 2)
1999         {
2000             switch (stopinfo->draggable->point_type) {
2001                 case POINT_LG_BEGIN:
2002                     {
2003                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2004
2005                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
2006                         NR::Point oldbegin = NR::Point (lg->x1.computed, lg->y1.computed);
2007                         NR::Point end = NR::Point (lg->x2.computed, lg->y2.computed);
2008                         SPStop *stop = sp_first_stop(stopinfo->vector);
2009                         gdouble offset = stop->offset;
2010                         NR::Point newbegin = oldbegin + offset * (end - oldbegin);
2011                         lg->x1.computed = newbegin[NR::X];
2012                         lg->y1.computed = newbegin[NR::Y];
2013
2014                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
2015                         sp_repr_set_svg_double(repr, "x1", lg->x1.computed);
2016                         sp_repr_set_svg_double(repr, "y1", lg->y1.computed);
2017                         stop->offset = 0;
2018                         sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", 0);
2019
2020                         // iterate through midstops to set new offset values such that they won't move on canvas.
2021                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2022                         stop = sp_next_stop(stop);
2023                         while ( stop != laststop ) {
2024                             stop->offset = (stop->offset - offset)/(1 - offset);
2025                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2026                             stop = sp_next_stop(stop);
2027                         }
2028                     }
2029                     break;
2030                 case POINT_LG_END:
2031                     {
2032                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2033
2034                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
2035                         NR::Point begin = NR::Point (lg->x1.computed, lg->y1.computed);
2036                         NR::Point oldend = NR::Point (lg->x2.computed, lg->y2.computed);
2037                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2038                         gdouble offset = laststop->offset;
2039                         NR::Point newend = begin + offset * (oldend - begin);
2040                         lg->x2.computed = newend[NR::X];
2041                         lg->y2.computed = newend[NR::Y];
2042
2043                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
2044                         sp_repr_set_svg_double(repr, "x2", lg->x2.computed);
2045                         sp_repr_set_svg_double(repr, "y2", lg->y2.computed);
2046                         laststop->offset = 1;
2047                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
2048
2049                         // iterate through midstops to set new offset values such that they won't move on canvas.
2050                         SPStop *stop = sp_first_stop(stopinfo->vector);
2051                         stop = sp_next_stop(stop);
2052                         while ( stop != laststop ) {
2053                             stop->offset = stop->offset / offset;
2054                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2055                             stop = sp_next_stop(stop);
2056                         }
2057                     }
2058                     break;
2059                 case POINT_RG_CENTER:
2060                     {
2061                         SPStop *newfirst = sp_next_stop (stopinfo->spstop);
2062                         if (newfirst) {
2063                             newfirst->offset = 0;
2064                             sp_repr_set_css_double (SP_OBJECT_REPR (newfirst), "offset", 0);
2065                         }
2066                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2067                     }
2068                     break;
2069                 case POINT_RG_R1:
2070                 case POINT_RG_R2:
2071                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2072
2073                         SPRadialGradient *rg = SP_RADIALGRADIENT(stopinfo->gradient);
2074                         double oldradius = rg->r.computed;
2075                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2076                         gdouble offset = laststop->offset;
2077                         double newradius = offset * oldradius;
2078                         rg->r.computed = newradius;
2079
2080                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(rg);
2081                         sp_repr_set_svg_double(repr, "r", rg->r.computed);
2082                         laststop->offset = 1;
2083                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
2084
2085                         // iterate through midstops to set new offset values such that they won't move on canvas.
2086                         SPStop *stop = sp_first_stop(stopinfo->vector);
2087                         stop = sp_next_stop(stop);
2088                         while ( stop != laststop ) {
2089                             stop->offset = stop->offset / offset;
2090                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2091                             stop = sp_next_stop(stop);
2092                         }
2093                         break;
2094             }
2095         }
2096         else
2097         { // delete the gradient from the object. set fill to unset  FIXME: set to fill of unselected node?
2098             SPCSSAttr *css = sp_repr_css_attr_new ();
2099
2100             // stopinfo->spstop is the selected stop
2101             Inkscape::XML::Node *unselectedrepr = SP_OBJECT_REPR(stopinfo->vector)->firstChild();
2102             if (unselectedrepr == SP_OBJECT_REPR(stopinfo->spstop) ) {
2103                 unselectedrepr = unselectedrepr->next();
2104             }
2105
2106             if (unselectedrepr == NULL) {
2107                 if (stopinfo->draggable->fill_or_stroke) {
2108                     sp_repr_css_unset_property (css, "fill");
2109                 } else {
2110                     sp_repr_css_unset_property (css, "stroke");
2111                 }
2112             } else {
2113                 SPCSSAttr *stopcss = sp_repr_css_attr(unselectedrepr, "style");
2114                 if (stopinfo->draggable->fill_or_stroke) {
2115                     sp_repr_css_set_property(css, "fill", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
2116                     sp_repr_css_set_property(css, "fill-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
2117                 } else {
2118                     sp_repr_css_set_property(css, "stroke", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
2119                     sp_repr_css_set_property(css, "stroke-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
2120                 }
2121                 sp_repr_css_attr_unref (stopcss);
2122             }
2123
2124             sp_repr_css_change (SP_OBJECT_REPR (stopinfo->draggable->item), css, "style");
2125             sp_repr_css_attr_unref (css);
2126         }
2127
2128         endstoplist = g_slist_remove(endstoplist, stopinfo);
2129         delete stopinfo;
2130     }
2131
2132     if (document) {
2133         sp_document_done ( document, SP_VERB_CONTEXT_GRADIENT, _("Delete gradient stop(s)") );
2134     }
2135 }
2136
2137
2138 /*
2139   Local Variables:
2140   mode:c++
2141   c-file-style:"stroustrup"
2142   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
2143   indent-tabs-mode:nil
2144   fill-column:99
2145   End:
2146 */
2147 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :