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     m.setup(desktop);
 598     if (!((state & GDK_SHIFT_MASK) || (state & GDK_CONTROL_MASK))) {
 599         Inkscape::SnappedPoint s = m.freeSnap(Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_OTHER_HANDLE));
 600         if (s.getSnapped()) {
 601             p = s.getPoint();
 602             sp_knot_moveto (knot, p);
 603         }
 604     } else if (state & GDK_CONTROL_MASK) {
 605         SnappedConstraints sc;
 606         Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 607         unsigned snaps = abs(prefs->getInt("/options/rotationsnapsperpi/value", 12));
 608         /* 0 means no snapping. */
 609
 610         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) {
 611             GrDraggable *draggable = (GrDraggable *) i->data;
 612
 613             Geom::Point dr_snap(Geom::infinity(), Geom::infinity());
 614
 615             if (draggable->point_type == POINT_LG_BEGIN || draggable->point_type == POINT_LG_END) {
 616                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 617                     GrDragger *d_new = (GrDragger *) di->data;
 618                     if (d_new == dragger)
 619                         continue;
 620                     if (d_new->isA (draggable->item,
 621                                     draggable->point_type == POINT_LG_BEGIN? POINT_LG_END : POINT_LG_BEGIN,
 622                                     draggable->fill_or_stroke)) {
 623                         // found the other end of the linear gradient;
 624                         if (state & GDK_SHIFT_MASK) {
 625                             // moving linear around center
 626                             Geom::Point center = Geom::Point (0.5*(d_new->point + dragger->point));
 627                             dr_snap = center;
 628                         } else {
 629                             // moving linear around the other end
 630                             dr_snap = d_new->point;
 631                         }
 632                     }
 633                 }
 634             } else if (draggable->point_type == POINT_RG_R1 || draggable->point_type == POINT_RG_R2 || draggable->point_type == POINT_RG_FOCUS) {
 635                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 636                     GrDragger *d_new = (GrDragger *) di->data;
 637                     if (d_new == dragger)
 638                         continue;
 639                     if (d_new->isA (draggable->item,
 640                                     POINT_RG_CENTER,
 641                                     draggable->fill_or_stroke)) {
 642                         // found the center of the radial gradient;
 643                         dr_snap = d_new->point;
 644                     }
 645                 }
 646             } else if (draggable->point_type == POINT_RG_CENTER) {
 647                 // radial center snaps to hor/vert relative to its original position
 648                 dr_snap = dragger->point_original;
 649             }
 650
 651             boost::optional<Geom::Point> snap_vector;
 652             if (dr_snap.isFinite()) {
 653                 if (state & GDK_MOD1_MASK) {
 654                     // with Alt, snap to the original angle and its perpendiculars
 655                     snap_vector = get_snap_vector (p, dr_snap, M_PI/2, Geom::atan2 (dragger->point_original - dr_snap));
 656                 } else {
 657                     // with Ctrl, snap to M_PI/snaps
 658                     snap_vector = get_snap_vector (p, dr_snap, M_PI/snaps, 0);
 659                 }
 660                 if (snap_vector) {
 661                     Inkscape::Snapper::ConstraintLine cl(dr_snap, p + *snap_vector - dr_snap);
 662                     Inkscape::SnappedPoint s = m.constrainedSnap(Inkscape::SnapCandidatePoint(p + *snap_vector, Inkscape::SNAPSOURCE_OTHER_HANDLE), cl);
 663                     if (s.getSnapped()) {
 664                         s.setTransformation(s.getPoint() - p);
 665                         sc.points.push_back(s);
 666                     } else {
 667                         Inkscape::SnappedPoint dummy(p + *snap_vector, Inkscape::SNAPSOURCE_OTHER_HANDLE, 0, Inkscape::SNAPTARGET_CONSTRAINED_ANGLE, Geom::L2(*snap_vector), 10000, true, false);
 668                         dummy.setTransformation(*snap_vector);
 669                         sc.points.push_back(dummy);
 670                     }
 671                 }
 672             }
 673         }
 674
 675         Inkscape::SnappedPoint bsp = m.findBestSnap(Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_OTHER_HANDLE), sc, true); // snap indicator will be displayed if needed
 676
 677         if (bsp.getSnapped()) {
 678             p += bsp.getTransformation();
 679             sp_knot_moveto (knot, p);
 680         }
 681     }
 682
 683     drag->keep_selection = (bool) g_list_find(drag->selected, dragger);
 684     bool scale_radial = (state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK);
 685
 686     if (drag->keep_selection) {
 687         Geom::Point diff = p - dragger->point;
 688         drag->selected_move_nowrite (diff[Geom::X], diff[Geom::Y], scale_radial);
 689     } else {
 690         dragger->point = p;
 691         dragger->fireDraggables (false, scale_radial);
 692         dragger->updateDependencies(false);
 693     }
 694
 695 }
 696
 697
 698 static void
 699 gr_midpoint_limits(GrDragger *dragger, SPObject *server, Geom::Point *begin, Geom::Point *end, Geom::Point *low_lim, Geom::Point *high_lim, GSList **moving)
 700 {
 701
 702     GrDrag *drag = dragger->parent;
 703     // a midpoint dragger can (logically) only contain one GrDraggable
 704     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 705
 706     // get begin and end points between which dragging is allowed:
 707     // the draglimits are between knot(lowest_i - 1) and knot(highest_i + 1)
 708     *moving = g_slist_append(*moving, dragger);
 709
 710     guint lowest_i = draggable->point_i;
 711     guint highest_i = draggable->point_i;
 712     GrDragger *lowest_dragger = dragger;
 713     GrDragger *highest_dragger = dragger;
 714     if (dragger->isSelected()) {
 715         GrDragger* d_add;
 716         while ( true )
 717         {
 718             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 719             if ( d_add && g_list_find(drag->selected, d_add) ) {
 720                 lowest_i = lowest_i - 1;
 721                 *moving = g_slist_prepend(*moving, d_add);
 722                 lowest_dragger = d_add;
 723             } else {
 724                 break;
 725             }
 726         }
 727
 728         while ( true )
 729         {
 730             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 731             if ( d_add && g_list_find(drag->selected, d_add) ) {
 732                 highest_i = highest_i + 1;
 733                 *moving = g_slist_append(*moving, d_add);
 734                 highest_dragger = d_add;
 735             } else {
 736                 break;
 737             }
 738         }
 739     }
 740
 741     if ( SP_IS_LINEARGRADIENT(server) ) {
 742         guint num = SP_LINEARGRADIENT(server)->vector.stops.size();
 743         GrDragger *d_temp;
 744         if (lowest_i == 1) {
 745             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke);
 746         } else {
 747             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, lowest_i - 1, draggable->fill_or_stroke);
 748         }
 749         if (d_temp)
 750             *begin = d_temp->point;
 751
 752         d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, highest_i + 1, draggable->fill_or_stroke);
 753         if (d_temp == NULL) {
 754             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_END, num-1, draggable->fill_or_stroke);
 755         }
 756         if (d_temp)
 757             *end = d_temp->point;
 758     } else if ( SP_IS_RADIALGRADIENT(server) ) {
 759         guint num = SP_RADIALGRADIENT(server)->vector.stops.size();
 760         GrDragger *d_temp;
 761         if (lowest_i == 1) {
 762             d_temp = drag->getDraggerFor (draggable->item, POINT_RG_CENTER, 0, draggable->fill_or_stroke);
 763         } else {
 764             d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 765         }
 766         if (d_temp)
 767             *begin = d_temp->point;
 768
 769         d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 770         if (d_temp == NULL) {
 771             d_temp = drag->getDraggerFor (draggable->item, (draggable->point_type==POINT_RG_MID1) ? POINT_RG_R1 : POINT_RG_R2, num-1, draggable->fill_or_stroke);
 772         }
 773         if (d_temp)
 774             *end = d_temp->point;
 775     }
 776
 777     *low_lim  = dragger->point - (lowest_dragger->point - *begin);
 778     *high_lim = dragger->point - (highest_dragger->point - *end);
 779 }
 780
 781
 782
 783 /**
 784 Called when a midpoint knot is dragged.
 785 */
 786 static void
 787 gr_knot_moved_midpoint_handler(SPKnot */*knot*/, Geom::Point const &ppointer, guint state, gpointer data)
 788 {
 789     GrDragger *dragger = (GrDragger *) data;
 790     GrDrag *drag = dragger->parent;
 791     // a midpoint dragger can (logically) only contain one GrDraggable
 792     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 793
 794     // FIXME: take from prefs
 795     double snap_fraction = 0.1;
 796
 797     Geom::Point p = ppointer;
 798     Geom::Point begin(0,0), end(0,0);
 799     Geom::Point low_lim(0,0), high_lim(0,0);
 800
 801     SPObject *server = draggable->getServer();
 802
 803     GSList *moving = NULL;
 804     gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
 805
 806     if (state & GDK_CONTROL_MASK) {
 807         p = snap_vector_midpoint (p, low_lim, high_lim, snap_fraction);
 808     } else {
 809         p = snap_vector_midpoint (p, low_lim, high_lim, 0);
 810         if (!(state & GDK_SHIFT_MASK)) {
 811             SPDesktop *desktop = dragger->parent->desktop;
 812             SnapManager &m = desktop->namedview->snap_manager;
 813             Inkscape::Snapper::ConstraintLine cl(low_lim, high_lim - low_lim);
 814             m.constrainedSnapReturnByRef(p, Inkscape::SNAPSOURCE_OTHER_HANDLE, cl);
 815         }
 816     }
 817     Geom::Point displacement = p - dragger->point;
 818
 819     for (GSList const* i = moving; i != NULL; i = i->next) {
 820         GrDragger *drg = (GrDragger*) i->data;
 821         SPKnot *drgknot = drg->knot;
 822         Geom::Point this_move = displacement;
 823         if (state & GDK_MOD1_MASK) {
 824             // FIXME: unify all these profiles (here, in nodepath, in tweak) in one place
 825             double alpha = 1.0;
 826             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
 827                 double x = Geom::L2(drg->point - dragger->point)/Geom::L2(end - dragger->point);
 828                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 829             } else { // drg is on the begin side from dragger
 830                 double x = Geom::L2(drg->point - dragger->point)/Geom::L2(begin - dragger->point);
 831                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 832             }
 833         }
 834         drg->point += this_move;
 835         sp_knot_moveto (drgknot, drg->point);
 836         drg->fireDraggables (false);
 837         drg->updateDependencies(false);
 838     }
 839
 840     g_slist_free(moving);
 841
 842     drag->keep_selection = dragger->isSelected();
 843 }
 844
 845
 846
 847 static void
 848 gr_knot_grabbed_handler (SPKnot */*knot*/, unsigned int /*state*/, gpointer data)
 849 {
 850     GrDragger *dragger = (GrDragger *) data;
 851
 852     sp_canvas_force_full_redraw_after_interruptions(dragger->parent->desktop->canvas, 5);
 853 }
 854
 855 /**
 856 Called when the mouse releases a dragger knot; changes gradient writing to repr, updates other draggers if needed
 857 */
 858 static void
 859 gr_knot_ungrabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 860 {
 861     GrDragger *dragger = (GrDragger *) data;
 862
 863     sp_canvas_end_forced_full_redraws(dragger->parent->desktop->canvas);
 864
 865     dragger->point_original = dragger->point = knot->pos;
 866
 867     if ((state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK)) {
 868         dragger->fireDraggables (true, true);
 869     } else {
 870         dragger->fireDraggables (true);
 871     }
 872
 873     for (GList *i = dragger->parent->selected; i != NULL; i = i->next) {
 874         GrDragger *d = (GrDragger *) i->data;
 875         if (d == dragger)
 876             continue;
 877         d->fireDraggables (true);
 878     }
 879
 880     // make this dragger selected
 881     if (!dragger->parent->keep_selection) {
 882         dragger->parent->setSelected (dragger);
 883     }
 884     dragger->parent->keep_selection = false;
 885
 886     dragger->updateDependencies(true);
 887
 888     // we did an undoable action
 889     sp_document_done (sp_desktop_document (dragger->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 890                       _("Move gradient handle"));
 891 }
 892
 893 /**
 894 Called when a dragger knot is clicked; selects the dragger or deletes it depending on the
 895 state of the keyboard keys
 896 */
 897 static void
 898 gr_knot_clicked_handler(SPKnot */*knot*/, guint state, gpointer data)
 899 {
 900     GrDragger *dragger = (GrDragger *) data;
 901     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 902     if (!draggable) return;
 903
 904     if ( (state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK ) ) {
 905     // delete this knot from vector
 906         SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
 907         gradient = sp_gradient_get_vector (gradient, false);
 908         if (gradient->vector.stops.size() > 2) { // 2 is the minimum
 909             SPStop *stop = NULL;
 910             switch (draggable->point_type) {  // if we delete first or last stop, move the next/previous to the edge
 911             case POINT_LG_BEGIN:
 912             case POINT_RG_CENTER:
 913                 stop = sp_first_stop(gradient);
 914                 {
 915                     SPStop *next = sp_next_stop (stop);
 916                     if (next) {
 917                         next->offset = 0;
 918                         sp_repr_set_css_double (SP_OBJECT_REPR (next), "offset", 0);
 919                     }
 920                 }
 921                 break;
 922             case POINT_LG_END:
 923             case POINT_RG_R1:
 924             case POINT_RG_R2:
 925                 stop = sp_last_stop(gradient);
 926                 {
 927                     SPStop *prev = sp_prev_stop (stop, gradient);
 928                     if (prev) {
 929                         prev->offset = 1;
 930                         sp_repr_set_css_double (SP_OBJECT_REPR (prev), "offset", 1);
 931                     }
 932                 }
 933                 break;
 934             case POINT_LG_MID:
 935             case POINT_RG_MID1:
 936             case POINT_RG_MID2:
 937                 stop = sp_get_stop_i(gradient, draggable->point_i);
 938                 break;
 939             }
 940
 941             SP_OBJECT_REPR(gradient)->removeChild(SP_OBJECT_REPR(stop));
 942             sp_document_done (SP_OBJECT_DOCUMENT (gradient), SP_VERB_CONTEXT_GRADIENT,
 943                       _("Delete gradient stop"));
 944         }
 945     } else {
 946     // select the dragger
 947         dragger->point_original = dragger->point;
 948
 949         if ( state & GDK_SHIFT_MASK ) {
 950             dragger->parent->setSelected (dragger, true, false);
 951         } else {
 952             dragger->parent->setSelected (dragger);
 953         }
 954     }
 955 }
 956
 957 /**
 958 Called when a dragger knot is doubleclicked; opens gradient editor with the stop from the first draggable
 959 */
 960 static void
 961 gr_knot_doubleclicked_handler (SPKnot */*knot*/, guint /*state*/, gpointer data)
 962 {
 963     GrDragger *dragger = (GrDragger *) data;
 964
 965     dragger->point_original = dragger->point;
 966
 967     if (dragger->draggables == NULL)
 968         return;
 969
 970     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 971     sp_item_gradient_edit_stop (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 972 }
 973
 974 /**
 975 Act upon all draggables of the dragger, setting them to the dragger's point
 976 */
 977 void
 978 GrDragger::fireDraggables (bool write_repr, bool scale_radial, bool merging_focus)
 979 {
 980     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 981         GrDraggable *draggable = (GrDraggable *) i->data;
 982
 983         // set local_change flag so that selection_changed callback does not regenerate draggers
 984         this->parent->local_change = true;
 985
 986         // change gradient, optionally writing to repr; prevent focus from moving if it's snapped
 987         // to the center, unless it's the first update upon merge when we must snap it to the point
 988         if (merging_focus ||
 989             !(draggable->point_type == POINT_RG_FOCUS && this->isA(draggable->item, POINT_RG_CENTER, draggable->point_i, draggable->fill_or_stroke)))
 990         {
 991             sp_item_gradient_set_coords (draggable->item, draggable->point_type, draggable->point_i, this->point, draggable->fill_or_stroke, write_repr, scale_radial);
 992         }
 993     }
 994 }
 995
 996 /**
 997 Checks if the dragger has a draggable with this point_type
 998  */
 999 bool
1000 GrDragger::isA (gint point_type)
1001 {
1002     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1003         GrDraggable *draggable = (GrDraggable *) i->data;
1004         if (draggable->point_type == point_type) {
1005             return true;
1006         }
1007     }
1008     return false;
1009 }
1010
1011 /**
1012 Checks if the dragger has a draggable with this item, point_type + point_i (number), fill_or_stroke
1013  */
1014 bool
1015 GrDragger::isA (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1016 {
1017     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1018         GrDraggable *draggable = (GrDraggable *) i->data;
1019         if ( (draggable->point_type == point_type) && (draggable->point_i == point_i) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
1020             return true;
1021         }
1022     }
1023     return false;
1024 }
1025
1026 /**
1027 Checks if the dragger has a draggable with this item, point_type, fill_or_stroke
1028  */
1029 bool
1030 GrDragger::isA (SPItem *item, gint point_type, bool fill_or_stroke)
1031 {
1032     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1033         GrDraggable *draggable = (GrDraggable *) i->data;
1034         if ( (draggable->point_type == point_type) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
1035             return true;
1036         }
1037     }
1038     return false;
1039 }
1040
1041 bool
1042 GrDraggable::mayMerge (GrDraggable *da2)
1043 {
1044     if ((this->item == da2->item) && (this->fill_or_stroke == da2->fill_or_stroke)) {
1045         // we must not merge the points of the same gradient!
1046         if (!((this->point_type == POINT_RG_FOCUS && da2->point_type == POINT_RG_CENTER) ||
1047               (this->point_type == POINT_RG_CENTER && da2->point_type == POINT_RG_FOCUS))) {
1048             // except that we can snap center and focus together
1049             return false;
1050         }
1051     }
1052     // disable merging of midpoints.
1053     if ( (this->point_type == POINT_LG_MID) || (da2->point_type == POINT_LG_MID)
1054          || (this->point_type == POINT_RG_MID1) || (da2->point_type == POINT_RG_MID1)
1055          || (this->point_type == POINT_RG_MID2) || (da2->point_type == POINT_RG_MID2) )
1056         return false;
1057
1058     return true;
1059 }
1060
1061 bool
1062 GrDragger::mayMerge (GrDragger *other)
1063 {
1064     if (this == other)
1065         return false;
1066
1067     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
1068         GrDraggable *da1 = (GrDraggable *) i->data;
1069         for (GSList const* j = other->draggables; j != NULL; j = j->next) { // for all draggables of other
1070             GrDraggable *da2 = (GrDraggable *) j->data;
1071             if (!da1->mayMerge(da2))
1072                 return false;
1073         }
1074     }
1075     return true;
1076 }
1077
1078 bool
1079 GrDragger::mayMerge (GrDraggable *da2)
1080 {
1081     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
1082         GrDraggable *da1 = (GrDraggable *) i->data;
1083         if (!da1->mayMerge(da2))
1084             return false;
1085     }
1086     return true;
1087 }
1088
1089 /**
1090 Updates the statusbar tip of the dragger knot, based on its draggables
1091  */
1092 void
1093 GrDragger::updateTip ()
1094 {
1095     if (this->knot && this->knot->tip) {
1096         g_free (this->knot->tip);
1097         this->knot->tip = NULL;
1098     }
1099
1100     if (g_slist_length (this->draggables) == 1) {
1101         GrDraggable *draggable = (GrDraggable *) this->draggables->data;
1102         char *item_desc = sp_item_description(draggable->item);
1103         switch (draggable->point_type) {
1104             case POINT_LG_MID:
1105             case POINT_RG_MID1:
1106             case POINT_RG_MID2:
1107                 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"),
1108                                                    _(gr_knot_descr[draggable->point_type]),
1109                                                    draggable->point_i,
1110                                                    item_desc,
1111                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
1112                 break;
1113
1114             default:
1115                 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"),
1116                                                    _(gr_knot_descr[draggable->point_type]),
1117                                                    item_desc,
1118                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
1119                 break;
1120         }
1121         g_free(item_desc);
1122     } else if (g_slist_length (draggables) == 2 && isA (POINT_RG_CENTER) && isA (POINT_RG_FOCUS)) {
1123         this->knot->tip = g_strdup_printf (_("Radial gradient <b>center</b> and <b>focus</b>; drag with <b>Shift</b> to separate focus"));
1124     } else {
1125         int length = g_slist_length (this->draggables);
1126         this->knot->tip = g_strdup_printf (ngettext("Gradient point shared by <b>%d</b> gradient; drag with <b>Shift</b> to separate",
1127                                                     "Gradient point shared by <b>%d</b> gradients; drag with <b>Shift</b> to separate",
1128                                                     length),
1129                                            length);
1130     }
1131 }
1132
1133 /**
1134 Adds a draggable to the dragger
1135  */
1136 void
1137 GrDragger::updateKnotShape ()
1138 {
1139     if (!draggables)
1140         return;
1141     GrDraggable *last = (GrDraggable *) g_slist_last(draggables)->data;
1142     g_object_set (G_OBJECT (this->knot->item), "shape", gr_knot_shapes[last->point_type], NULL);
1143 }
1144
1145 /**
1146 Adds a draggable to the dragger
1147  */
1148 void
1149 GrDragger::addDraggable (GrDraggable *draggable)
1150 {
1151     this->draggables = g_slist_prepend (this->draggables, draggable);
1152
1153     this->updateTip();
1154 }
1155
1156
1157 /**
1158 Moves this dragger to the point of the given draggable, acting upon all other draggables
1159  */
1160 void
1161 GrDragger::moveThisToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1162 {
1163     GrDraggable *dr_first = (GrDraggable *) this->draggables->data;
1164     if (!dr_first) return;
1165
1166     this->point = sp_item_gradient_get_coords (dr_first->item, dr_first->point_type, dr_first->point_i, dr_first->fill_or_stroke);
1167     this->point_original = this->point;
1168
1169     sp_knot_moveto (this->knot, this->point);
1170
1171     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1172         GrDraggable *da = (GrDraggable *) i->data;
1173         if ( (da->item == item) &&
1174              (point_type == -1 || da->point_type == point_type) &&
1175              (point_i == -1 || da->point_i == point_i) &&
1176              (da->fill_or_stroke == fill_or_stroke) ) {
1177             continue;
1178         }
1179         sp_item_gradient_set_coords (da->item, da->point_type, da->point_i, this->point, da->fill_or_stroke, write_repr, false);
1180     }
1181     // FIXME: here we should also call this->updateDependencies(write_repr); to propagate updating, but how to prevent loops?
1182 }
1183
1184
1185 /**
1186 Moves all midstop draggables that depend on this one
1187  */
1188 void
1189 GrDragger::updateMidstopDependencies (GrDraggable *draggable, bool write_repr) {
1190     SPObject *server = draggable->getServer();
1191     if (!server)
1192         return;
1193     guint num = SP_GRADIENT(server)->vector.stops.size();
1194     if (num <= 2) return;
1195
1196     if ( SP_IS_LINEARGRADIENT(server) ) {
1197         for ( guint i = 1; i < num - 1; i++ ) {
1198             this->moveOtherToDraggable (draggable->item, POINT_LG_MID, i, draggable->fill_or_stroke, write_repr);
1199         }
1200     } else  if ( SP_IS_RADIALGRADIENT(server) ) {
1201         for ( guint i = 1; i < num - 1; i++ ) {
1202             this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, i, draggable->fill_or_stroke, write_repr);
1203             this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, i, draggable->fill_or_stroke, write_repr);
1204         }
1205     }
1206 }
1207
1208
1209 /**
1210 Moves all draggables that depend on this one
1211  */
1212 void
1213 GrDragger::updateDependencies (bool write_repr)
1214 {
1215     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1216         GrDraggable *draggable = (GrDraggable *) i->data;
1217         switch (draggable->point_type) {
1218             case POINT_LG_BEGIN:
1219                 {
1220                     // the end point is dependent only when dragging with ctrl+shift
1221                     this->moveOtherToDraggable (draggable->item, POINT_LG_END, -1, draggable->fill_or_stroke, write_repr);
1222
1223                     this->updateMidstopDependencies (draggable, write_repr);
1224                 }
1225                 break;
1226             case POINT_LG_END:
1227                 {
1228                     // the begin point is dependent only when dragging with ctrl+shift
1229                     this->moveOtherToDraggable (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke, write_repr);
1230
1231                     this->updateMidstopDependencies (draggable, write_repr);
1232                 }
1233                 break;
1234             case POINT_LG_MID:
1235                 // no other nodes depend on mid points.
1236                 break;
1237             case POINT_RG_R2:
1238                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1239                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1240                 this->updateMidstopDependencies (draggable, write_repr);
1241                 break;
1242             case POINT_RG_R1:
1243                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1244                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1245                 this->updateMidstopDependencies (draggable, write_repr);
1246                 break;
1247             case POINT_RG_CENTER:
1248                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1249                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1250                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1251                 this->updateMidstopDependencies (draggable, write_repr);
1252                 break;
1253             case POINT_RG_FOCUS:
1254                 // nothing can depend on that
1255                 break;
1256             case POINT_RG_MID1:
1257                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, draggable->point_i, draggable->fill_or_stroke, write_repr);
1258                 break;
1259             case POINT_RG_MID2:
1260                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, draggable->point_i, draggable->fill_or_stroke, write_repr);
1261                 break;
1262             default:
1263                 break;
1264         }
1265     }
1266 }
1267
1268
1269
1270 GrDragger::GrDragger (GrDrag *parent, Geom::Point p, GrDraggable *draggable)
1271   : point(p),
1272     point_original(p)
1273 {
1274     this->draggables = NULL;
1275
1276     this->parent = parent;
1277
1278     // create the knot
1279     this->knot = sp_knot_new (parent->desktop, NULL);
1280     this->knot->setMode(SP_KNOT_MODE_XOR);
1281     this->knot->setFill(GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_MOUSEOVER, GR_KNOT_COLOR_MOUSEOVER);
1282     this->knot->setStroke(0x0000007f, 0x0000007f, 0x0000007f);
1283     sp_knot_update_ctrl(this->knot);
1284
1285     // move knot to the given point
1286     sp_knot_set_position (this->knot, p, SP_KNOT_STATE_NORMAL);
1287     sp_knot_show (this->knot);
1288
1289     // connect knot's signals
1290     if ( (draggable)  // it can be NULL if a node in unsnapped (eg. focus point unsnapped from center)
1291                        // luckily, midstops never snap to other nodes so are never unsnapped...
1292          && ( (draggable->point_type == POINT_LG_MID)
1293               || (draggable->point_type == POINT_RG_MID1)
1294               || (draggable->point_type == POINT_RG_MID2) ) )
1295     {
1296         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_midpoint_handler), this);
1297     } else {
1298         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_handler), this);
1299     }
1300     g_signal_connect (G_OBJECT (this->knot), "clicked", G_CALLBACK (gr_knot_clicked_handler), this);
1301     g_signal_connect (G_OBJECT (this->knot), "doubleclicked", G_CALLBACK (gr_knot_doubleclicked_handler), this);
1302     g_signal_connect (G_OBJECT (this->knot), "grabbed", G_CALLBACK (gr_knot_grabbed_handler), this);
1303     g_signal_connect (G_OBJECT (this->knot), "ungrabbed", G_CALLBACK (gr_knot_ungrabbed_handler), this);
1304
1305     // add the initial draggable
1306     if (draggable)
1307         this->addDraggable (draggable);
1308     updateKnotShape();
1309 }
1310
1311 GrDragger::~GrDragger ()
1312 {
1313     // unselect if it was selected
1314     this->parent->setDeselected(this);
1315
1316     // disconnect signals
1317     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_moved_handler), this);
1318     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_clicked_handler), this);
1319     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_doubleclicked_handler), this);
1320     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_grabbed_handler), this);
1321     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_ungrabbed_handler), this);
1322
1323     /* unref should call destroy */
1324     g_object_unref (G_OBJECT (this->knot));
1325
1326     // delete all draggables
1327     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1328         delete ((GrDraggable *) i->data);
1329     }
1330     g_slist_free (this->draggables);
1331     this->draggables = NULL;
1332 }
1333
1334 /**
1335 Select the dragger which has the given draggable.
1336 */
1337 GrDragger *
1338 GrDrag::getDraggerFor (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1339 {
1340     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1341         GrDragger *dragger = (GrDragger *) i->data;
1342         for (GSList const* j = dragger->draggables; j != NULL; j = j->next) {
1343             GrDraggable *da2 = (GrDraggable *) j->data;
1344             if ( (da2->item == item) &&
1345                  (point_type == -1 || da2->point_type == point_type) && // -1 means this does not matter
1346                  (point_i == -1 || da2->point_i == point_i) && // -1 means this does not matter
1347                  (da2->fill_or_stroke == fill_or_stroke)) {
1348                 return (dragger);
1349             }
1350         }
1351     }
1352     return NULL;
1353 }
1354
1355
1356 void
1357 GrDragger::moveOtherToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1358 {
1359     GrDragger *d = this->parent->getDraggerFor (item, point_type, point_i, fill_or_stroke);
1360     if (d && d !=  this) {
1361         d->moveThisToDraggable (item, point_type, point_i, fill_or_stroke, write_repr);
1362     }
1363 }
1364
1365
1366 /**
1367   Draw this dragger as selected
1368 */
1369 void
1370 GrDragger::select()
1371 {
1372     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_SELECTED;
1373     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_SELECTED, NULL);
1374 }
1375
1376 /**
1377   Draw this dragger as normal (deselected)
1378 */
1379 void
1380 GrDragger::deselect()
1381 {
1382     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_NORMAL;
1383     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_NORMAL, NULL);
1384 }
1385
1386 bool
1387 GrDragger::isSelected()
1388 {
1389     return g_list_find (parent->selected, this);
1390 }
1391
1392 /**
1393 \brief Deselect all stops/draggers (private)
1394 */
1395 void
1396 GrDrag::deselect_all()
1397 {
1398     while (selected) {
1399         ( (GrDragger*) selected->data)->deselect();
1400         selected = g_list_remove(selected, selected->data);
1401     }
1402 }
1403
1404 /**
1405 \brief Deselect all stops/draggers (public; emits signal)
1406 */
1407 void
1408 GrDrag::deselectAll()
1409 {
1410     deselect_all();
1411     this->desktop->emitToolSubselectionChanged(NULL);
1412 }
1413
1414 /**
1415 \brief Select all stops/draggers
1416 */
1417 void
1418 GrDrag::selectAll()
1419 {
1420     for (GList *l = this->draggers; l != NULL; l = l->next) {
1421         GrDragger *d = ((GrDragger *) l->data);
1422         setSelected (d, true, true);
1423     }
1424 }
1425
1426 /**
1427 \brief Select all stops/draggers that match the coords
1428 */
1429 void
1430 GrDrag::selectByCoords(std::vector<Geom::Point> coords)
1431 {
1432     for (GList *l = this->draggers; l != NULL; l = l->next) {
1433         GrDragger *d = ((GrDragger *) l->data);
1434         for (guint k = 0; k < coords.size(); k++) {
1435             if (Geom::L2 (d->point - coords[k]) < 1e-4) {
1436                 setSelected (d, true, true);
1437             }
1438         }
1439     }
1440 }
1441
1442
1443 /**
1444 \brief Select all stops/draggers that fall within the rect
1445 */
1446 void
1447 GrDrag::selectRect(Geom::Rect const &r)
1448 {
1449     for (GList *l = this->draggers; l != NULL; l = l->next) {
1450         GrDragger *d = ((GrDragger *) l->data);
1451         if (r.contains(d->point)) {
1452            setSelected (d, true, true);
1453         }
1454     }
1455 }
1456
1457 /**
1458 \brief Select a dragger
1459 \param dragger       The dragger to select
1460 \param add_to_selection   If true, add to selection, otherwise deselect others
1461 \param override      If true, always select this node, otherwise toggle selected status
1462 */
1463 void
1464 GrDrag::setSelected (GrDragger *dragger, bool add_to_selection, bool override)
1465 {
1466     GrDragger *seldragger = NULL;
1467
1468     if (add_to_selection) {
1469         if (!dragger) return;
1470         if (override) {
1471             if (!g_list_find(selected, dragger)) {
1472                 selected = g_list_prepend(selected, dragger);
1473             }
1474             dragger->select();
1475             seldragger = dragger;
1476         } else { // toggle
1477             if (g_list_find(selected, dragger)) {
1478                 selected = g_list_remove(selected, dragger);
1479                 dragger->deselect();
1480                 if (selected) {
1481                     seldragger = (GrDragger*) selected->data; // select the dragger that is first in the list
1482                 }
1483             } else {
1484                 selected = g_list_prepend(selected, dragger);
1485                 dragger->select();
1486                 seldragger = dragger;
1487             }
1488         }
1489     } else {
1490         deselect_all();
1491         if (dragger) {
1492             selected = g_list_prepend(selected, dragger);
1493             dragger->select();
1494             seldragger = dragger;
1495         }
1496     }
1497     if (seldragger) {
1498         this->desktop->emitToolSubselectionChanged((gpointer) seldragger);
1499     }
1500 }
1501
1502 /**
1503 \brief Deselect a dragger
1504 \param dragger       The dragger to deselect
1505 */
1506 void
1507 GrDrag::setDeselected (GrDragger *dragger)
1508 {
1509     if (g_list_find(selected, dragger)) {
1510         selected = g_list_remove(selected, dragger);
1511         dragger->deselect();
1512     }
1513     this->desktop->emitToolSubselectionChanged((gpointer) (selected ? selected->data : NULL ));
1514 }
1515
1516
1517
1518 /**
1519 Create a line from p1 to p2 and add it to the lines list
1520  */
1521 void
1522 GrDrag::addLine (SPItem *item, Geom::Point p1, Geom::Point p2, guint32 rgba)
1523 {
1524     SPCanvasItem *line = sp_canvas_item_new(sp_desktop_controls(this->desktop),
1525                                                             SP_TYPE_CTRLLINE, NULL);
1526     sp_canvas_item_move_to_z(line, 0);
1527     SP_CTRLLINE(line)->item = item;
1528     sp_ctrlline_set_coords(SP_CTRLLINE(line), p1, p2);
1529     if (rgba != GR_LINE_COLOR_FILL) // fill is the default, so don't set color for it to speed up redraw
1530         sp_ctrlline_set_rgba32 (SP_CTRLLINE(line), rgba);
1531     sp_canvas_item_show (line);
1532     this->lines = g_slist_append (this->lines, line);
1533 }
1534
1535 /**
1536 If there already exists a dragger within MERGE_DIST of p, add the draggable to it; otherwise create
1537 new dragger and add it to draggers list
1538  */
1539 void
1540 GrDrag::addDragger (GrDraggable *draggable)
1541 {
1542     Geom::Point p = sp_item_gradient_get_coords (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
1543
1544     for (GList *i = this->draggers; i != NULL; i = i->next) {
1545         GrDragger *dragger = (GrDragger *) i->data;
1546         if (dragger->mayMerge (draggable) && Geom::L2 (dragger->point - p) < MERGE_DIST) {
1547             // distance is small, merge this draggable into dragger, no need to create new dragger
1548             dragger->addDraggable (draggable);
1549             dragger->updateKnotShape();
1550             return;
1551         }
1552     }
1553
1554     GrDragger *new_dragger = new GrDragger(this, p, draggable);
1555     // fixme: draggers should be added AFTER the last one: this way tabbing through them will be from begin to end.
1556     this->draggers = g_list_append (this->draggers, new_dragger);
1557 }
1558
1559 /**
1560 Add draggers for the radial gradient rg on item
1561 */
1562 void
1563 GrDrag::addDraggersRadial (SPRadialGradient *rg, SPItem *item, bool fill_or_stroke)
1564 {
1565     addDragger (new GrDraggable (item, POINT_RG_CENTER, 0, fill_or_stroke));
1566     guint num = rg->vector.stops.size();
1567     if (num > 2) {
1568         for ( guint i = 1; i < num - 1; i++ ) {
1569             addDragger (new GrDraggable (item, POINT_RG_MID1, i, fill_or_stroke));
1570         }
1571     }
1572     addDragger (new GrDraggable (item, POINT_RG_R1, num-1, fill_or_stroke));
1573     if (num > 2) {
1574         for ( guint i = 1; i < num - 1; i++ ) {
1575             addDragger (new GrDraggable (item, POINT_RG_MID2, i, fill_or_stroke));
1576         }
1577     }
1578     addDragger (new GrDraggable (item, POINT_RG_R2, num-1, fill_or_stroke));
1579     addDragger (new GrDraggable (item, POINT_RG_FOCUS, 0, fill_or_stroke));
1580 }
1581
1582 /**
1583 Add draggers for the linear gradient lg on item
1584 */
1585 void
1586 GrDrag::addDraggersLinear (SPLinearGradient *lg, SPItem *item, bool fill_or_stroke)
1587 {
1588     addDragger (new GrDraggable (item, POINT_LG_BEGIN, 0, fill_or_stroke));
1589     guint num = lg->vector.stops.size();
1590     if (num > 2) {
1591         for ( guint i = 1; i < num - 1; i++ ) {
1592             addDragger (new GrDraggable (item, POINT_LG_MID, i, fill_or_stroke));
1593         }
1594     }
1595     addDragger (new GrDraggable (item, POINT_LG_END, num-1, fill_or_stroke));
1596 }
1597
1598 /**
1599 Artificially grab the knot of this dragger; used by the gradient context
1600 */
1601 void
1602 GrDrag::grabKnot (GrDragger *dragger, gint x, gint y, guint32 etime)
1603 {
1604     if (dragger) {
1605         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1606     }
1607 }
1608
1609 /**
1610 Artificially grab the knot of the dragger with this draggable; used by the gradient context
1611 */
1612 void
1613 GrDrag::grabKnot (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, gint x, gint y, guint32 etime)
1614 {
1615     GrDragger *dragger = getDraggerFor (item, point_type, point_i, fill_or_stroke);
1616     if (dragger) {
1617         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1618     }
1619 }
1620
1621 /**
1622 Regenerates the draggers list from the current selection; is called when selection is changed or
1623 modified, also when a radial dragger needs to update positions of other draggers in the gradient
1624 */
1625 void
1626 GrDrag::updateDraggers ()
1627 {
1628     while (selected) {
1629         selected = g_list_remove(selected, selected->data);
1630     }
1631     // delete old draggers
1632     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1633         delete ((GrDragger *) i->data);
1634     }
1635     g_list_free (this->draggers);
1636     this->draggers = NULL;
1637
1638     g_return_if_fail (this->selection != NULL);
1639
1640     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1641
1642         SPItem *item = SP_ITEM(i->data);
1643         SPStyle *style = SP_OBJECT_STYLE (item);
1644
1645         if (style && (style->fill.isPaintserver())) {
1646             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1647             if (SP_IS_LINEARGRADIENT (server)) {
1648                 addDraggersLinear (SP_LINEARGRADIENT (server), item, true);
1649             } else if (SP_IS_RADIALGRADIENT (server)) {
1650                 addDraggersRadial (SP_RADIALGRADIENT (server), item, true);
1651             }
1652         }
1653
1654         if (style && (style->stroke.isPaintserver())) {
1655             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1656             if (SP_IS_LINEARGRADIENT (server)) {
1657                 addDraggersLinear (SP_LINEARGRADIENT (server), item, false);
1658             } else if (SP_IS_RADIALGRADIENT (server)) {
1659                 addDraggersRadial (SP_RADIALGRADIENT (server), item, false);
1660             }
1661         }
1662     }
1663 }
1664
1665 /**
1666 Regenerates the lines list from the current selection; is called on each move of a dragger, so that
1667 lines are always in sync with the actual gradient
1668 */
1669 void
1670 GrDrag::updateLines ()
1671 {
1672     // delete old lines
1673     for (GSList const *i = this->lines; i != NULL; i = i->next) {
1674         gtk_object_destroy( GTK_OBJECT (i->data));
1675     }
1676     g_slist_free (this->lines);
1677     this->lines = NULL;
1678
1679     g_return_if_fail (this->selection != NULL);
1680
1681     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1682
1683         SPItem *item = SP_ITEM(i->data);
1684
1685         SPStyle *style = SP_OBJECT_STYLE (item);
1686
1687         if (style && (style->fill.isPaintserver())) {
1688             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1689             if (SP_IS_LINEARGRADIENT (server)) {
1690                 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);
1691             } else if (SP_IS_RADIALGRADIENT (server)) {
1692                 Geom::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, true);
1693                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, true), GR_LINE_COLOR_FILL);
1694                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, true), GR_LINE_COLOR_FILL);
1695             }
1696         }
1697
1698         if (style && (style->stroke.isPaintserver())) {
1699             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1700             if (SP_IS_LINEARGRADIENT (server)) {
1701                 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);
1702             } else if (SP_IS_RADIALGRADIENT (server)) {
1703                 Geom::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, false);
1704                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, false), GR_LINE_COLOR_STROKE);
1705                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, false), GR_LINE_COLOR_STROKE);
1706             }
1707         }
1708     }
1709 }
1710
1711 /**
1712 Regenerates the levels list from the current selection
1713 */
1714 void
1715 GrDrag::updateLevels ()
1716 {
1717     hor_levels.clear();
1718     vert_levels.clear();
1719
1720     g_return_if_fail (this->selection != NULL);
1721
1722     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1723         SPItem *item = SP_ITEM(i->data);
1724         Geom::OptRect rect = sp_item_bbox_desktop (item);
1725         if (rect) {
1726             // Remember the edges of the bbox and the center axis
1727             hor_levels.push_back(rect->min()[Geom::Y]);
1728             hor_levels.push_back(rect->max()[Geom::Y]);
1729             hor_levels.push_back(0.5 * (rect->min()[Geom::Y] + rect->max()[Geom::Y]));
1730             vert_levels.push_back(rect->min()[Geom::X]);
1731             vert_levels.push_back(rect->max()[Geom::X]);
1732             vert_levels.push_back(0.5 * (rect->min()[Geom::X] + rect->max()[Geom::X]));
1733         }
1734     }
1735 }
1736
1737 void
1738 GrDrag::selected_reverse_vector ()
1739 {
1740     if (selected == NULL)
1741         return;
1742
1743     for (GSList const* i = ( (GrDragger*) selected->data )->draggables; i != NULL; i = i->next) {
1744         GrDraggable *draggable = (GrDraggable *) i->data;
1745
1746         sp_item_gradient_reverse_vector (draggable->item, draggable->fill_or_stroke);
1747     }
1748 }
1749
1750 void
1751 GrDrag::selected_move_nowrite (double x, double y, bool scale_radial)
1752 {
1753     selected_move (x, y, false, scale_radial);
1754 }
1755
1756 void
1757 GrDrag::selected_move (double x, double y, bool write_repr, bool scale_radial)
1758 {
1759     if (selected == NULL)
1760         return;
1761
1762     bool did = false;
1763
1764     for (GList *i = selected; i != NULL; i = i->next) {
1765         GrDragger *d = (GrDragger *) i->data;
1766
1767         if (!d->isA(POINT_LG_MID) && !d->isA(POINT_RG_MID1) && !d->isA(POINT_RG_MID2)) {
1768             // if this is an endpoint,
1769
1770             // Moving an rg center moves its focus and radii as well.
1771             // therefore, if this is a focus or radius and if selection
1772             // contains the center as well, do not move this one
1773             if (d->isA(POINT_RG_R1) || d->isA(POINT_RG_R2) ||
1774                 (d->isA(POINT_RG_FOCUS) && !d->isA(POINT_RG_CENTER))) {
1775                 bool skip_radius_with_center = false;
1776                 for (GList *di = selected; di != NULL; di = di->next) {
1777                     GrDragger *d_new = (GrDragger *) di->data;
1778                     if (d_new->isA (((GrDraggable *) d->draggables->data)->item,
1779                                     POINT_RG_CENTER,
1780                                     0,
1781                                     ((GrDraggable *) d->draggables->data)->fill_or_stroke)) {
1782                         // FIXME: here we take into account only the first draggable!
1783                         skip_radius_with_center = true;
1784                     }
1785                 }
1786                 if (skip_radius_with_center)
1787                     continue;
1788             }
1789
1790             did = true;
1791             d->point += Geom::Point (x, y);
1792             d->point_original = d->point;
1793             sp_knot_moveto (d->knot, d->point);
1794
1795             d->fireDraggables (write_repr, scale_radial);
1796
1797             d->updateDependencies(write_repr);
1798         }
1799     }
1800
1801     if (write_repr && did) {
1802         // we did an undoable action
1803         sp_document_maybe_done (sp_desktop_document (desktop), "grmoveh", SP_VERB_CONTEXT_GRADIENT,
1804                                 _("Move gradient handle(s)"));
1805         return;
1806     }
1807
1808     if (!did) { // none of the end draggers are selected, so let's try to move the mids
1809
1810         GrDragger *dragger = (GrDragger *) selected->data;
1811         // a midpoint dragger can (logically) only contain one GrDraggable
1812         GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
1813
1814         Geom::Point begin(0,0), end(0,0);
1815         Geom::Point low_lim(0,0), high_lim(0,0);
1816
1817         SPObject *server = draggable->getServer();
1818         GSList *moving = NULL;
1819         gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
1820
1821         Geom::Point p(x, y);
1822         p = snap_vector_midpoint (dragger->point + p, low_lim, high_lim, 0);
1823         Geom::Point displacement = p - dragger->point;
1824
1825         for (GSList const* i = moving; i != NULL; i = i->next) {
1826             GrDragger *drg = (GrDragger*) i->data;
1827             SPKnot *drgknot = drg->knot;
1828             drg->point += displacement;
1829             sp_knot_moveto (drgknot, drg->point);
1830             drg->fireDraggables (true);
1831             drg->updateDependencies(true);
1832             did = true;
1833         }
1834
1835         g_slist_free(moving);
1836
1837         if (write_repr && did) {
1838             // we did an undoable action
1839             sp_document_maybe_done (sp_desktop_document (desktop), "grmovem", SP_VERB_CONTEXT_GRADIENT,
1840                                     _("Move gradient mid stop(s)"));
1841         }
1842     }
1843 }
1844
1845 void
1846 GrDrag::selected_move_screen (double x, double y)
1847 {
1848     gdouble zoom = desktop->current_zoom();
1849     gdouble zx = x / zoom;
1850     gdouble zy = y / zoom;
1851
1852     selected_move (zx, zy);
1853 }
1854
1855 /**
1856 Select the knot next to the last selected one and deselect all other selected.
1857 */
1858 GrDragger *
1859 GrDrag::select_next ()
1860 {
1861     GrDragger *d = NULL;
1862     if (selected == NULL || g_list_find(draggers, selected->data)->next == NULL) {
1863         if (draggers)
1864             d = (GrDragger *) draggers->data;
1865     } else {
1866         d = (GrDragger *) g_list_find(draggers, selected->data)->next->data;
1867     }
1868     if (d)
1869         setSelected (d);
1870     return d;
1871 }
1872
1873 /**
1874 Select the knot previous from the last selected one and deselect all other selected.
1875 */
1876 GrDragger *
1877 GrDrag::select_prev ()
1878 {
1879     GrDragger *d = NULL;
1880     if (selected == NULL || g_list_find(draggers, selected->data)->prev == NULL) {
1881         if (draggers)
1882             d = (GrDragger *) g_list_last (draggers)->data;
1883     } else {
1884         d = (GrDragger *) g_list_find(draggers, selected->data)->prev->data;
1885     }
1886     if (d)
1887         setSelected (d);
1888     return d;
1889 }
1890
1891
1892 // FIXME: i.m.o. an ugly function that I just made to work, but... aargh! (Johan)
1893 void
1894 GrDrag::deleteSelected (bool just_one)
1895 {
1896     if (!selected) return;
1897
1898     SPDocument *document = false;
1899
1900     struct StructStopInfo {
1901         SPStop * spstop;
1902         GrDraggable * draggable;
1903         SPGradient * gradient;
1904         SPGradient * vector;
1905     };
1906
1907     GSList *midstoplist = NULL;  // list of stops that must be deleted (will be deleted first)
1908     GSList *endstoplist = NULL;  // list of stops that must be deleted
1909     while (selected) {
1910         GrDragger *dragger = (GrDragger*) selected->data;
1911         for (GSList * drgble = dragger->draggables; drgble != NULL; drgble = drgble->next) {
1912             GrDraggable *draggable = (GrDraggable*) drgble->data;
1913             SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
1914             SPGradient *vector   = sp_gradient_get_forked_vector_if_necessary (gradient, false);
1915
1916             switch (draggable->point_type) {
1917                 case POINT_LG_MID:
1918                 case POINT_RG_MID1:
1919                 case POINT_RG_MID2:
1920                     {
1921                         SPStop *stop = sp_get_stop_i(vector, draggable->point_i);
1922                         // check if already present in list. (e.g. when both RG_MID1 and RG_MID2 were selected)
1923                         bool present = false;
1924                         for (GSList const * l = midstoplist; l != NULL; l = l->next) {
1925                             if ( (SPStop*)l->data == stop ) {
1926                                 present = true;
1927                                 break; // no need to search further.
1928                             }
1929                         }
1930                         if (!present)
1931                             midstoplist = g_slist_append(midstoplist, stop);
1932                     }
1933                     break;
1934                 case POINT_LG_BEGIN:
1935                 case POINT_LG_END:
1936                 case POINT_RG_CENTER:
1937                 case POINT_RG_R1:
1938                 case POINT_RG_R2:
1939                     {
1940                         SPStop *stop = NULL;
1941                         if ( (draggable->point_type == POINT_LG_BEGIN) || (draggable->point_type == POINT_RG_CENTER) ) {
1942                             stop = sp_first_stop(vector);
1943                         } else {
1944                             stop = sp_last_stop(vector);
1945                         }
1946                         if (stop) {
1947                             StructStopInfo *stopinfo = new StructStopInfo;
1948                             stopinfo->spstop = stop;
1949                             stopinfo->draggable = draggable;
1950                             stopinfo->gradient = gradient;
1951                             stopinfo->vector = vector;
1952                             // check if already present in list. (e.g. when both R1 and R2 were selected)
1953                             bool present = false;
1954                             for (GSList const * l = endstoplist; l != NULL; l = l->next) {
1955                                 if ( ((StructStopInfo*)l->data)->spstop == stopinfo->spstop ) {
1956                                     present = true;
1957                                     break; // no need to search further.
1958                                 }
1959                             }
1960                             if (!present)
1961                                 endstoplist = g_slist_append(endstoplist, stopinfo);
1962                         }
1963                     }
1964                     break;
1965                 default:
1966                     break;
1967             }
1968         }
1969         selected = g_list_remove(selected, dragger);
1970         if ( just_one ) break; // iterate once if just_one is set.
1971     }
1972     while (midstoplist) {
1973         SPStop *stop = (SPStop*) midstoplist->data;
1974         document = SP_OBJECT_DOCUMENT (stop);
1975         Inkscape::XML::Node * parent = SP_OBJECT_REPR(stop)->parent();
1976         parent->removeChild(SP_OBJECT_REPR(stop));
1977         midstoplist = g_slist_remove(midstoplist, stop);
1978     }
1979     while (endstoplist) {
1980         StructStopInfo *stopinfo  = (StructStopInfo*) endstoplist->data;
1981         document = SP_OBJECT_DOCUMENT (stopinfo->spstop);
1982
1983         // 2 is the minimum, cannot delete more than that without deleting the whole vector
1984         // cannot use vector->vector.stops.size() because the vector might be invalidated by deletion of a midstop
1985         // manually count the children, don't know if there already exists a function for this...
1986         int len = 0;
1987         for ( SPObject *child = sp_object_first_child(stopinfo->vector) ;
1988               child != NULL ;
1989               child = SP_OBJECT_NEXT(child) )
1990         {
1991             if ( SP_IS_STOP(child) )  len ++;
1992         }
1993         if (len > 2)
1994         {
1995             switch (stopinfo->draggable->point_type) {
1996                 case POINT_LG_BEGIN:
1997                     {
1998                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
1999
2000                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
2001                         Geom::Point oldbegin = Geom::Point (lg->x1.computed, lg->y1.computed);
2002                         Geom::Point end = Geom::Point (lg->x2.computed, lg->y2.computed);
2003                         SPStop *stop = sp_first_stop(stopinfo->vector);
2004                         gdouble offset = stop->offset;
2005                         Geom::Point newbegin = oldbegin + offset * (end - oldbegin);
2006                         lg->x1.computed = newbegin[Geom::X];
2007                         lg->y1.computed = newbegin[Geom::Y];
2008
2009                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
2010                         sp_repr_set_svg_double(repr, "x1", lg->x1.computed);
2011                         sp_repr_set_svg_double(repr, "y1", lg->y1.computed);
2012                         stop->offset = 0;
2013                         sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", 0);
2014
2015                         // iterate through midstops to set new offset values such that they won't move on canvas.
2016                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2017                         stop = sp_next_stop(stop);
2018                         while ( stop != laststop ) {
2019                             stop->offset = (stop->offset - offset)/(1 - offset);
2020                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2021                             stop = sp_next_stop(stop);
2022                         }
2023                     }
2024                     break;
2025                 case POINT_LG_END:
2026                     {
2027                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2028
2029                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
2030                         Geom::Point begin = Geom::Point (lg->x1.computed, lg->y1.computed);
2031                         Geom::Point oldend = Geom::Point (lg->x2.computed, lg->y2.computed);
2032                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2033                         gdouble offset = laststop->offset;
2034                         Geom::Point newend = begin + offset * (oldend - begin);
2035                         lg->x2.computed = newend[Geom::X];
2036                         lg->y2.computed = newend[Geom::Y];
2037
2038                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
2039                         sp_repr_set_svg_double(repr, "x2", lg->x2.computed);
2040                         sp_repr_set_svg_double(repr, "y2", lg->y2.computed);
2041                         laststop->offset = 1;
2042                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
2043
2044                         // iterate through midstops to set new offset values such that they won't move on canvas.
2045                         SPStop *stop = sp_first_stop(stopinfo->vector);
2046                         stop = sp_next_stop(stop);
2047                         while ( stop != laststop ) {
2048                             stop->offset = stop->offset / offset;
2049                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2050                             stop = sp_next_stop(stop);
2051                         }
2052                     }
2053                     break;
2054                 case POINT_RG_CENTER:
2055                     {
2056                         SPStop *newfirst = sp_next_stop (stopinfo->spstop);
2057                         if (newfirst) {
2058                             newfirst->offset = 0;
2059                             sp_repr_set_css_double (SP_OBJECT_REPR (newfirst), "offset", 0);
2060                         }
2061                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2062                     }
2063                     break;
2064                 case POINT_RG_R1:
2065                 case POINT_RG_R2:
2066                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2067
2068                         SPRadialGradient *rg = SP_RADIALGRADIENT(stopinfo->gradient);
2069                         double oldradius = rg->r.computed;
2070                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2071                         gdouble offset = laststop->offset;
2072                         double newradius = offset * oldradius;
2073                         rg->r.computed = newradius;
2074
2075                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(rg);
2076                         sp_repr_set_svg_double(repr, "r", rg->r.computed);
2077                         laststop->offset = 1;
2078                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
2079
2080                         // iterate through midstops to set new offset values such that they won't move on canvas.
2081                         SPStop *stop = sp_first_stop(stopinfo->vector);
2082                         stop = sp_next_stop(stop);
2083                         while ( stop != laststop ) {
2084                             stop->offset = stop->offset / offset;
2085                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2086                             stop = sp_next_stop(stop);
2087                         }
2088                         break;
2089             }
2090         }
2091         else
2092         { // delete the gradient from the object. set fill to unset  FIXME: set to fill of unselected node?
2093             SPCSSAttr *css = sp_repr_css_attr_new ();
2094
2095             // stopinfo->spstop is the selected stop
2096             Inkscape::XML::Node *unselectedrepr = SP_OBJECT_REPR(stopinfo->vector)->firstChild();
2097             if (unselectedrepr == SP_OBJECT_REPR(stopinfo->spstop) ) {
2098                 unselectedrepr = unselectedrepr->next();
2099             }
2100
2101             if (unselectedrepr == NULL) {
2102                 if (stopinfo->draggable->fill_or_stroke) {
2103                     sp_repr_css_unset_property (css, "fill");
2104                 } else {
2105                     sp_repr_css_unset_property (css, "stroke");
2106                 }
2107             } else {
2108                 SPCSSAttr *stopcss = sp_repr_css_attr(unselectedrepr, "style");
2109                 if (stopinfo->draggable->fill_or_stroke) {
2110                     sp_repr_css_set_property(css, "fill", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
2111                     sp_repr_css_set_property(css, "fill-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
2112                 } else {
2113                     sp_repr_css_set_property(css, "stroke", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
2114                     sp_repr_css_set_property(css, "stroke-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
2115                 }
2116                 sp_repr_css_attr_unref (stopcss);
2117             }
2118
2119             sp_repr_css_change (SP_OBJECT_REPR (stopinfo->draggable->item), css, "style");
2120             sp_repr_css_attr_unref (css);
2121         }
2122
2123         endstoplist = g_slist_remove(endstoplist, stopinfo);
2124         delete stopinfo;
2125     }
2126
2127     if (document) {
2128         sp_document_done ( document, SP_VERB_CONTEXT_GRADIENT, _("Delete gradient stop(s)") );
2129     }
2130 }
2131
2132
2133 /*
2134   Local Variables:
2135   mode:c++
2136   c-file-style:"stroustrup"
2137   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
2138   indent-tabs-mode:nil
2139   fill-column:99
2140   End:
2141 */
2142 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :