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  *   Jon A. Cruz <jon@joncruz.org>
  10  *
  11  * Copyright (C) 2007 Johan Engelen
  12  * Copyright (C) 2005,2010 Authors
  13  *
  14  * Released under GNU GPL, read the file 'COPYING' for more information
  15  */
  16
  17 #ifdef HAVE_CONFIG_H
  18 #include "config.h"
  19 #endif
  20
  21 #include <glibmm/i18n.h>
  22 #include <cstring>
  23 #include <string>
  24
  25 #include "desktop-handles.h"
  26 #include "selection.h"
  27 #include "desktop.h"
  28 #include "desktop-style.h"
  29 #include "document.h"
  30 #include "display/sp-ctrlline.h"
  31 #include "display/sp-canvas-util.h"
  32 #include "xml/repr.h"
  33 #include "svg/css-ostringstream.h"
  34 #include "svg/svg.h"
  35 #include "libnr/nr-point-fns.h"
  36 #include "preferences.h"
  37 #include "sp-item.h"
  38 #include "style.h"
  39 #include "knot.h"
  40 #include "sp-linear-gradient.h"
  41 #include "sp-radial-gradient.h"
  42 #include "gradient-chemistry.h"
  43 #include "gradient-drag.h"
  44 #include "sp-stop.h"
  45 #include "snap.h"
  46 #include "sp-namedview.h"
  47 #include "selection-chemistry.h"
  48
  49 #define GR_KNOT_COLOR_NORMAL 0xffffff00
  50 #define GR_KNOT_COLOR_MOUSEOVER 0xff000000
  51 #define GR_KNOT_COLOR_SELECTED 0x0000ff00
  52
  53 #define GR_LINE_COLOR_FILL 0x0000ff7f
  54 #define GR_LINE_COLOR_STROKE 0x9999007f
  55
  56 // screen pixels between knots when they snap:
  57 #define SNAP_DIST 5
  58
  59 // absolute distance between gradient points for them to become a single dragger when the drag is created:
  60 #define MERGE_DIST 0.1
  61
  62 // knot shapes corresponding to GrPointType enum
  63 SPKnotShapeType gr_knot_shapes [] = {
  64         SP_KNOT_SHAPE_SQUARE, //POINT_LG_BEGIN
  65         SP_KNOT_SHAPE_CIRCLE,  //POINT_LG_END
  66         SP_KNOT_SHAPE_DIAMOND, //POINT_LG_MID
  67         SP_KNOT_SHAPE_SQUARE,  // POINT_RG_CENTER
  68         SP_KNOT_SHAPE_CIRCLE,  // POINT_RG_R1
  69         SP_KNOT_SHAPE_CIRCLE,  // POINT_RG_R2
  70         SP_KNOT_SHAPE_CROSS, // POINT_RG_FOCUS
  71         SP_KNOT_SHAPE_DIAMOND, //POINT_RG_MID1
  72         SP_KNOT_SHAPE_DIAMOND //POINT_RG_MID2
  73 };
  74
  75 const gchar *gr_knot_descr [] = {
  76     N_("Linear gradient <b>start</b>"), //POINT_LG_BEGIN
  77     N_("Linear gradient <b>end</b>"),
  78     N_("Linear gradient <b>mid stop</b>"),
  79     N_("Radial gradient <b>center</b>"),
  80     N_("Radial gradient <b>radius</b>"),
  81     N_("Radial gradient <b>radius</b>"),
  82     N_("Radial gradient <b>focus</b>"), // POINT_RG_FOCUS
  83     N_("Radial gradient <b>mid stop</b>"),
  84     N_("Radial gradient <b>mid stop</b>")
  85 };
  86
  87 static void
  88 gr_drag_sel_changed(Inkscape::Selection */*selection*/, gpointer data)
  89 {
  90     GrDrag *drag = (GrDrag *) data;
  91     drag->updateDraggers ();
  92     drag->updateLines ();
  93     drag->updateLevels ();
  94 }
  95
  96 static void
  97 gr_drag_sel_modified (Inkscape::Selection */*selection*/, guint /*flags*/, gpointer data)
  98 {
  99     GrDrag *drag = (GrDrag *) data;
 100     if (drag->local_change) {
 101         drag->local_change = false;
 102     } else {
 103         drag->updateDraggers ();
 104     }
 105     drag->updateLines ();
 106     drag->updateLevels ();
 107 }
 108
 109 /**
 110 When a _query_style_signal is received, check that \a property requests fill/stroke/opacity (otherwise
 111 skip), and fill the \a style with the averaged color of all draggables of the selected dragger, if
 112 any.
 113 */
 114 int
 115 gr_drag_style_query (SPStyle *style, int property, gpointer data)
 116 {
 117     GrDrag *drag = (GrDrag *) data;
 118
 119     if (property != QUERY_STYLE_PROPERTY_FILL && property != QUERY_STYLE_PROPERTY_STROKE && property != QUERY_STYLE_PROPERTY_MASTEROPACITY) {
 120         return QUERY_STYLE_NOTHING;
 121     }
 122
 123     if (!drag->selected) {
 124         return QUERY_STYLE_NOTHING;
 125     } else {
 126         int ret = QUERY_STYLE_NOTHING;
 127
 128         float cf[4];
 129         cf[0] = cf[1] = cf[2] = cf[3] = 0;
 130
 131         int count = 0;
 132
 133         for (GList *i = drag->selected; i != NULL; i = i->next) { // for all selected draggers
 134             GrDragger *d = (GrDragger *) i->data;
 135             for (GSList const* j = d->draggables; j != NULL; j = j->next) { // for all draggables of dragger
 136                 GrDraggable *draggable = (GrDraggable *) j->data;
 137
 138                 if (ret == QUERY_STYLE_NOTHING) {
 139                     ret = QUERY_STYLE_SINGLE;
 140                 } else if (ret == QUERY_STYLE_SINGLE) {
 141                     ret = QUERY_STYLE_MULTIPLE_AVERAGED;
 142                 }
 143
 144                 guint32 c = sp_item_gradient_stop_query_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 145                 cf[0] += SP_RGBA32_R_F (c);
 146                 cf[1] += SP_RGBA32_G_F (c);
 147                 cf[2] += SP_RGBA32_B_F (c);
 148                 cf[3] += SP_RGBA32_A_F (c);
 149
 150                 count ++;
 151             }
 152         }
 153
 154         if (count) {
 155             cf[0] /= count;
 156             cf[1] /= count;
 157             cf[2] /= count;
 158             cf[3] /= count;
 159
 160             // set both fill and stroke with our stop-color and stop-opacity
 161             style->fill.clear();
 162             style->fill.setColor( cf[0], cf[1], cf[2] );
 163             style->fill.set = TRUE;
 164             style->stroke.clear();
 165             style->stroke.setColor( cf[0], cf[1], cf[2] );
 166             style->stroke.set = TRUE;
 167
 168             style->fill_opacity.value = SP_SCALE24_FROM_FLOAT (1.0);
 169             style->fill_opacity.set = TRUE;
 170             style->stroke_opacity.value = SP_SCALE24_FROM_FLOAT (1.0);
 171             style->stroke_opacity.set = TRUE;
 172
 173             style->opacity.value = SP_SCALE24_FROM_FLOAT (cf[3]);
 174             style->opacity.set = TRUE;
 175         }
 176
 177         return ret;
 178     }
 179 }
 180
 181 bool
 182 gr_drag_style_set (const SPCSSAttr *css, gpointer data)
 183 {
 184     GrDrag *drag = (GrDrag *) data;
 185
 186     if (!drag->selected)
 187         return false;
 188
 189     SPCSSAttr *stop = sp_repr_css_attr_new ();
 190
 191     // See if the css contains interesting properties, and if so, translate them into the format
 192     // acceptable for gradient stops
 193
 194     // any of color properties, in order of increasing priority:
 195     if (css->attribute("flood-color"))
 196         sp_repr_css_set_property (stop, "stop-color", css->attribute("flood-color"));
 197
 198     if (css->attribute("lighting-color"))
 199         sp_repr_css_set_property (stop, "stop-color", css->attribute("lighting-color"));
 200
 201     if (css->attribute("color"))
 202         sp_repr_css_set_property (stop, "stop-color", css->attribute("color"));
 203
 204     if (css->attribute("stroke") && strcmp(css->attribute("stroke"), "none"))
 205         sp_repr_css_set_property (stop, "stop-color", css->attribute("stroke"));
 206
 207     if (css->attribute("fill") && strcmp(css->attribute("fill"), "none"))
 208         sp_repr_css_set_property (stop, "stop-color", css->attribute("fill"));
 209
 210     if (css->attribute("stop-color"))
 211         sp_repr_css_set_property (stop, "stop-color", css->attribute("stop-color"));
 212
 213
 214     if (css->attribute("stop-opacity")) { // direct setting of stop-opacity has priority
 215         sp_repr_css_set_property (stop, "stop-opacity", css->attribute("stop-opacity"));
 216     } else {  // multiply all opacity properties:
 217         gdouble accumulated = 1.0;
 218         accumulated *= sp_svg_read_percentage(css->attribute("flood-opacity"), 1.0);
 219         accumulated *= sp_svg_read_percentage(css->attribute("opacity"), 1.0);
 220         accumulated *= sp_svg_read_percentage(css->attribute("stroke-opacity"), 1.0);
 221         accumulated *= sp_svg_read_percentage(css->attribute("fill-opacity"), 1.0);
 222
 223         Inkscape::CSSOStringStream os;
 224         os << accumulated;
 225         sp_repr_css_set_property (stop, "stop-opacity", os.str().c_str());
 226
 227         if ((css->attribute("fill") && !css->attribute("stroke") && !strcmp(css->attribute("fill"), "none")) ||
 228             (css->attribute("stroke") && !css->attribute("fill") && !strcmp(css->attribute("stroke"), "none")))
 229             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
 230     }
 231
 232     if (!stop->attributeList()) { // nothing for us here, pass it on
 233         sp_repr_css_attr_unref(stop);
 234         return false;
 235     }
 236
 237     for (GList const* sel = drag->selected; sel != NULL; sel = sel->next) { // for all selected draggers
 238         GrDragger* dragger = (GrDragger*) sel->data;
 239         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 240                GrDraggable *draggable = (GrDraggable *) i->data;
 241
 242                drag->local_change = true;
 243                sp_item_gradient_stop_set_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke, stop);
 244         }
 245     }
 246
 247     //sp_repr_css_print(stop);
 248     sp_repr_css_attr_unref(stop);
 249     return true;
 250 }
 251
 252 guint32 GrDrag::getColor()
 253 {
 254     if (!selected) return 0;
 255
 256     float cf[4];
 257     cf[0] = cf[1] = cf[2] = cf[3] = 0;
 258
 259     int count = 0;
 260
 261     for (GList *i = selected; i != NULL; i = i->next) { // for all selected draggers
 262         GrDragger *d = (GrDragger *) i->data;
 263         for (GSList const* j = d->draggables; j != NULL; j = j->next) { // for all draggables of dragger
 264             GrDraggable *draggable = (GrDraggable *) j->data;
 265
 266             guint32 c = sp_item_gradient_stop_query_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 267             cf[0] += SP_RGBA32_R_F (c);
 268             cf[1] += SP_RGBA32_G_F (c);
 269             cf[2] += SP_RGBA32_B_F (c);
 270             cf[3] += SP_RGBA32_A_F (c);
 271
 272             count ++;
 273         }
 274     }
 275
 276     if (count) {
 277         cf[0] /= count;
 278         cf[1] /= count;
 279         cf[2] /= count;
 280         cf[3] /= count;
 281     }
 282
 283     return SP_RGBA32_F_COMPOSE(cf[0], cf[1], cf[2], cf[3]);
 284 }
 285
 286 SPStop *
 287 GrDrag::addStopNearPoint (SPItem *item, Geom::Point mouse_p, double tolerance)
 288 {
 289     gfloat offset; // type of SPStop.offset = gfloat
 290     SPGradient *gradient;
 291     bool fill_or_stroke = true;
 292     bool r1_knot = false;
 293
 294     bool addknot = false;
 295     do {
 296         gradient = sp_item_gradient (item, fill_or_stroke);
 297         if (SP_IS_LINEARGRADIENT(gradient)) {
 298             Geom::Point begin   = sp_item_gradient_get_coords(item, POINT_LG_BEGIN, 0, fill_or_stroke);
 299             Geom::Point end     = sp_item_gradient_get_coords(item, POINT_LG_END, 0, fill_or_stroke);
 300
 301             Geom::Point nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 302             double dist_screen = Geom::L2 (mouse_p - nearest);
 303             if ( dist_screen < tolerance ) {
 304                 // add the knot
 305                 offset = get_offset_between_points(nearest, begin, end);
 306                 addknot = true;
 307                 break; // break out of the while loop: add only one knot
 308             }
 309         } else if (SP_IS_RADIALGRADIENT(gradient)) {
 310             Geom::Point begin = sp_item_gradient_get_coords(item, POINT_RG_CENTER, 0, fill_or_stroke);
 311             Geom::Point end   = sp_item_gradient_get_coords(item, POINT_RG_R1, 0, fill_or_stroke);
 312             Geom::Point nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 313             double dist_screen = Geom::L2 (mouse_p - nearest);
 314             if ( dist_screen < tolerance ) {
 315                 offset = get_offset_between_points(nearest, begin, end);
 316                 addknot = true;
 317                 r1_knot = true;
 318                 break; // break out of the while loop: add only one knot
 319             }
 320
 321             end    = sp_item_gradient_get_coords(item, POINT_RG_R2, 0, fill_or_stroke);
 322             nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 323             dist_screen = Geom::L2 (mouse_p - nearest);
 324             if ( dist_screen < tolerance ) {
 325                 offset = get_offset_between_points(nearest, begin, end);
 326                 addknot = true;
 327                 r1_knot = false;
 328                 break; // break out of the while loop: add only one knot
 329             }
 330         }
 331         fill_or_stroke = !fill_or_stroke;
 332     } while (!fill_or_stroke && !addknot) ;
 333
 334     if (addknot) {
 335         SPGradient *vector = sp_gradient_get_forked_vector_if_necessary (gradient, false);
 336         SPStop* prev_stop = vector->getFirstStop();
 337         SPStop* next_stop = prev_stop->getNextStop();
 338         guint i = 1;
 339         while ( (next_stop) && (next_stop->offset < offset) ) {
 340             prev_stop = next_stop;
 341             next_stop = next_stop->getNextStop();
 342             i++;
 343         }
 344         if (!next_stop) {
 345             // logical error: the endstop should have offset 1 and should always be more than this offset here
 346             return NULL;
 347         }
 348
 349
 350         SPStop *newstop = sp_vector_add_stop (vector, prev_stop, next_stop, offset);
 351         gradient->ensureVector();
 352         updateDraggers();
 353
 354         return newstop;
 355     }
 356
 357     return NULL;
 358 }
 359
 360
 361 bool
 362 GrDrag::dropColor(SPItem */*item*/, gchar const *c, Geom::Point p)
 363 {
 364     // first, see if we can drop onto one of the existing draggers
 365     for (GList *i = draggers; i != NULL; i = i->next) { // for all draggables of dragger
 366         GrDragger *d = (GrDragger *) i->data;
 367
 368         if (Geom::L2(p - d->point)*desktop->current_zoom() < 5) {
 369            SPCSSAttr *stop = sp_repr_css_attr_new ();
 370            sp_repr_css_set_property (stop, "stop-color", c);
 371            sp_repr_css_set_property (stop, "stop-opacity", "1");
 372            for (GSList *j = d->draggables; j != NULL; j = j->next) { // for all draggables of dragger
 373                GrDraggable *draggable = (GrDraggable *) j->data;
 374                local_change = true;
 375                sp_item_gradient_stop_set_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke, stop);
 376            }
 377            sp_repr_css_attr_unref(stop);
 378            return true;
 379         }
 380     }
 381
 382     // now see if we're over line and create a new stop
 383     bool over_line = false;
 384     SPCtrlLine *line = NULL;
 385     if (lines) {
 386         for (GSList *l = lines; (l != NULL) && (!over_line); l = l->next) {
 387             line = (SPCtrlLine*) l->data;
 388             Geom::Point nearest = snap_vector_midpoint (p, line->s, line->e, 0);
 389             double dist_screen = Geom::L2 (p - nearest) * desktop->current_zoom();
 390             if (line->item && dist_screen < 5) {
 391                 SPStop *stop = addStopNearPoint (line->item, p, 5/desktop->current_zoom());
 392                 if (stop) {
 393                     SPCSSAttr *css = sp_repr_css_attr_new ();
 394                     sp_repr_css_set_property (css, "stop-color", c);
 395                     sp_repr_css_set_property (css, "stop-opacity", "1");
 396                     sp_repr_css_change (SP_OBJECT_REPR (stop), css, "style");
 397                     return true;
 398                 }
 399             }
 400         }
 401     }
 402
 403     return false;
 404 }
 405
 406
 407 GrDrag::GrDrag(SPDesktop *desktop) {
 408
 409     this->desktop = desktop;
 410
 411     this->selection = sp_desktop_selection(desktop);
 412
 413     this->draggers = NULL;
 414     this->lines = NULL;
 415     this->selected = NULL;
 416
 417     this->hor_levels.clear();
 418     this->vert_levels.clear();
 419
 420     this->local_change = false;
 421
 422     this->sel_changed_connection = this->selection->connectChanged(
 423         sigc::bind (
 424             sigc::ptr_fun(&gr_drag_sel_changed),
 425             (gpointer)this )
 426
 427         );
 428     this->sel_modified_connection = this->selection->connectModified(
 429         sigc::bind(
 430             sigc::ptr_fun(&gr_drag_sel_modified),
 431             (gpointer)this )
 432         );
 433
 434     this->style_set_connection = this->desktop->connectSetStyle(
 435         sigc::bind(
 436             sigc::ptr_fun(&gr_drag_style_set),
 437             (gpointer)this )
 438         );
 439
 440     this->style_query_connection = this->desktop->connectQueryStyle(
 441         sigc::bind(
 442             sigc::ptr_fun(&gr_drag_style_query),
 443             (gpointer)this )
 444         );
 445
 446     this->updateDraggers ();
 447     this->updateLines ();
 448     this->updateLevels ();
 449
 450     if (desktop->gr_item) {
 451         this->setSelected (getDraggerFor (desktop->gr_item, desktop->gr_point_type, desktop->gr_point_i, desktop->gr_fill_or_stroke));
 452     }
 453 }
 454
 455 GrDrag::~GrDrag()
 456 {
 457     this->sel_changed_connection.disconnect();
 458     this->sel_modified_connection.disconnect();
 459     this->style_set_connection.disconnect();
 460     this->style_query_connection.disconnect();
 461
 462     if (this->selected) {
 463         GrDraggable *draggable = (GrDraggable *)   ((GrDragger*)this->selected->data)->draggables->data;
 464         desktop->gr_item = draggable->item;
 465         desktop->gr_point_type = draggable->point_type;
 466         desktop->gr_point_i = draggable->point_i;
 467         desktop->gr_fill_or_stroke = draggable->fill_or_stroke;
 468     } else {
 469         desktop->gr_item = NULL;
 470         desktop->gr_point_type = 0;
 471         desktop->gr_point_i = 0;
 472         desktop->gr_fill_or_stroke = true;
 473     }
 474
 475     deselect_all();
 476     for (GList *l = this->draggers; l != NULL; l = l->next) {
 477         delete ((GrDragger *) l->data);
 478     }
 479     g_list_free (this->draggers);
 480     this->draggers = NULL;
 481     this->selected = NULL;
 482
 483     for (GSList *l = this->lines; l != NULL; l = l->next) {
 484         gtk_object_destroy( GTK_OBJECT (l->data));
 485     }
 486     g_slist_free (this->lines);
 487     this->lines = NULL;
 488 }
 489
 490 GrDraggable::GrDraggable (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke)
 491 {
 492     this->item = item;
 493     this->point_type = point_type;
 494     this->point_i = point_i;
 495     this->fill_or_stroke = fill_or_stroke;
 496
 497     g_object_ref (G_OBJECT (this->item));
 498 }
 499
 500 GrDraggable::~GrDraggable ()
 501 {
 502     g_object_unref (G_OBJECT (this->item));
 503 }
 504
 505
 506 SPObject *
 507 GrDraggable::getServer ()
 508 {
 509     if (!item)
 510         return NULL;
 511
 512     SPObject *server = NULL;
 513     if (fill_or_stroke)
 514         server = SP_OBJECT_STYLE_FILL_SERVER (item);
 515     else
 516         server = SP_OBJECT_STYLE_STROKE_SERVER (item);
 517
 518     return server;
 519 }
 520
 521 static
 522 boost::optional<Geom::Point>
 523 get_snap_vector (Geom::Point p, Geom::Point o, double snap, double initial)
 524 {
 525     double r = L2 (p - o);
 526     if (r < 1e-3) {
 527         return boost::optional<Geom::Point>();
 528     }
 529
 530     double angle = atan2 (p - o);
 531     // snap angle to snaps increments, starting from initial:
 532     double a_snapped = initial + floor((angle - initial)/snap + 0.5) * snap;
 533     // calculate the new position and subtract p to get the vector:
 534     return (o + r * Geom::Point(cos(a_snapped), sin(a_snapped)) - p);
 535 }
 536
 537 static void
 538 gr_knot_moved_handler(SPKnot *knot, Geom::Point const &ppointer, guint state, gpointer data)
 539 {
 540     GrDragger *dragger = (GrDragger *) data;
 541     GrDrag *drag = dragger->parent;
 542
 543     Geom::Point p = ppointer;
 544
 545     SPDesktop *desktop = dragger->parent->desktop;
 546     SnapManager &m = desktop->namedview->snap_manager;
 547     double snap_dist = m.snapprefs.getObjectTolerance() / dragger->parent->desktop->current_zoom();
 548
 549     if (state & GDK_SHIFT_MASK) {
 550         // with Shift; unsnap if we carry more than one draggable
 551         if (dragger->draggables && dragger->draggables->next) {
 552             // create a new dragger
 553             GrDragger *dr_new = new GrDragger (dragger->parent, dragger->point, NULL);
 554             dragger->parent->draggers = g_list_prepend (dragger->parent->draggers, dr_new);
 555             // relink to it all but the first draggable in the list
 556             for (GSList const* i = dragger->draggables->next; i != NULL; i = i->next) {
 557                 GrDraggable *draggable = (GrDraggable *) i->data;
 558                 dr_new->addDraggable (draggable);
 559             }
 560             dr_new->updateKnotShape();
 561             g_slist_free (dragger->draggables->next);
 562             dragger->draggables->next = NULL;
 563             dragger->updateKnotShape();
 564             dragger->updateTip();
 565         }
 566     } else if (!(state & GDK_CONTROL_MASK)) {
 567         // without Shift or Ctrl; see if we need to snap to another dragger
 568         for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 569             GrDragger *d_new = (GrDragger *) di->data;
 570             if (dragger->mayMerge(d_new) && Geom::L2 (d_new->point - p) < snap_dist) {
 571
 572                 // Merge draggers:
 573                 for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 574                     GrDraggable *draggable = (GrDraggable *) i->data;
 575                     // copy draggable to d_new:
 576                     GrDraggable *da_new = new GrDraggable (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 577                     d_new->addDraggable (da_new);
 578                 }
 579
 580                 // unlink and delete this dragger
 581                 dragger->parent->draggers = g_list_remove (dragger->parent->draggers, dragger);
 582                 delete dragger;
 583
 584                 // update the new merged dragger
 585                 d_new->fireDraggables(true, false, true);
 586                 d_new->parent->updateLines();
 587                 d_new->parent->setSelected (d_new);
 588                 d_new->updateKnotShape ();
 589                 d_new->updateTip ();
 590                 d_new->updateDependencies(true);
 591                 SPDocumentUndo::done (sp_desktop_document (d_new->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 592                                   _("Merge gradient handles"));
 593                 return;
 594             }
 595         }
 596     }
 597
 598     m.setup(desktop);
 599     if (!((state & GDK_SHIFT_MASK) || (state & GDK_CONTROL_MASK))) {
 600         Inkscape::SnappedPoint s = m.freeSnap(Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_OTHER_HANDLE));
 601         if (s.getSnapped()) {
 602             p = s.getPoint();
 603             sp_knot_moveto (knot, p);
 604         }
 605     } else if (state & GDK_CONTROL_MASK) {
 606         SnappedConstraints sc;
 607         Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 608         unsigned snaps = abs(prefs->getInt("/options/rotationsnapsperpi/value", 12));
 609         /* 0 means no snapping. */
 610
 611         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) {
 612             GrDraggable *draggable = (GrDraggable *) i->data;
 613
 614             Geom::Point dr_snap(Geom::infinity(), Geom::infinity());
 615
 616             if (draggable->point_type == POINT_LG_BEGIN || draggable->point_type == POINT_LG_END) {
 617                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 618                     GrDragger *d_new = (GrDragger *) di->data;
 619                     if (d_new == dragger)
 620                         continue;
 621                     if (d_new->isA (draggable->item,
 622                                     draggable->point_type == POINT_LG_BEGIN? POINT_LG_END : POINT_LG_BEGIN,
 623                                     draggable->fill_or_stroke)) {
 624                         // found the other end of the linear gradient;
 625                         if (state & GDK_SHIFT_MASK) {
 626                             // moving linear around center
 627                             Geom::Point center = Geom::Point (0.5*(d_new->point + dragger->point));
 628                             dr_snap = center;
 629                         } else {
 630                             // moving linear around the other end
 631                             dr_snap = d_new->point;
 632                         }
 633                     }
 634                 }
 635             } else if (draggable->point_type == POINT_RG_R1 || draggable->point_type == POINT_RG_R2 || draggable->point_type == POINT_RG_FOCUS) {
 636                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 637                     GrDragger *d_new = (GrDragger *) di->data;
 638                     if (d_new == dragger)
 639                         continue;
 640                     if (d_new->isA (draggable->item,
 641                                     POINT_RG_CENTER,
 642                                     draggable->fill_or_stroke)) {
 643                         // found the center of the radial gradient;
 644                         dr_snap = d_new->point;
 645                     }
 646                 }
 647             } else if (draggable->point_type == POINT_RG_CENTER) {
 648                 // radial center snaps to hor/vert relative to its original position
 649                 dr_snap = dragger->point_original;
 650             }
 651
 652             boost::optional<Geom::Point> snap_vector;
 653             if (dr_snap.isFinite()) {
 654                 if (state & GDK_MOD1_MASK) {
 655                     // with Alt, snap to the original angle and its perpendiculars
 656                     snap_vector = get_snap_vector (p, dr_snap, M_PI/2, Geom::atan2 (dragger->point_original - dr_snap));
 657                 } else {
 658                     // with Ctrl, snap to M_PI/snaps
 659                     snap_vector = get_snap_vector (p, dr_snap, M_PI/snaps, 0);
 660                 }
 661                 if (snap_vector) {
 662                     Inkscape::Snapper::ConstraintLine cl(dr_snap, p + *snap_vector - dr_snap);
 663                     Inkscape::SnappedPoint s = m.constrainedSnap(Inkscape::SnapCandidatePoint(p + *snap_vector, Inkscape::SNAPSOURCE_OTHER_HANDLE), cl);
 664                     if (s.getSnapped()) {
 665                         s.setTransformation(s.getPoint() - p);
 666                         sc.points.push_back(s);
 667                     } else {
 668                         Inkscape::SnappedPoint dummy(p + *snap_vector, Inkscape::SNAPSOURCE_OTHER_HANDLE, 0, Inkscape::SNAPTARGET_CONSTRAINED_ANGLE, Geom::L2(*snap_vector), 10000, true, true, false);
 669                         dummy.setTransformation(*snap_vector);
 670                         sc.points.push_back(dummy);
 671                     }
 672                 }
 673             }
 674         }
 675
 676         Inkscape::SnappedPoint bsp = m.findBestSnap(Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_OTHER_HANDLE), sc, true); // snap indicator will be displayed if needed
 677
 678         if (bsp.getSnapped()) {
 679             p += bsp.getTransformation();
 680             sp_knot_moveto (knot, p);
 681         }
 682     }
 683
 684     drag->keep_selection = (bool) g_list_find(drag->selected, dragger);
 685     bool scale_radial = (state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK);
 686
 687     if (drag->keep_selection) {
 688         Geom::Point diff = p - dragger->point;
 689         drag->selected_move_nowrite (diff[Geom::X], diff[Geom::Y], scale_radial);
 690     } else {
 691         dragger->point = p;
 692         dragger->fireDraggables (false, scale_radial);
 693         dragger->updateDependencies(false);
 694     }
 695
 696 }
 697
 698
 699 static void
 700 gr_midpoint_limits(GrDragger *dragger, SPObject *server, Geom::Point *begin, Geom::Point *end, Geom::Point *low_lim, Geom::Point *high_lim, GSList **moving)
 701 {
 702
 703     GrDrag *drag = dragger->parent;
 704     // a midpoint dragger can (logically) only contain one GrDraggable
 705     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 706
 707     // get begin and end points between which dragging is allowed:
 708     // the draglimits are between knot(lowest_i - 1) and knot(highest_i + 1)
 709     *moving = g_slist_append(*moving, dragger);
 710
 711     guint lowest_i = draggable->point_i;
 712     guint highest_i = draggable->point_i;
 713     GrDragger *lowest_dragger = dragger;
 714     GrDragger *highest_dragger = dragger;
 715     if (dragger->isSelected()) {
 716         GrDragger* d_add;
 717         while ( true )
 718         {
 719             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 720             if ( d_add && g_list_find(drag->selected, d_add) ) {
 721                 lowest_i = lowest_i - 1;
 722                 *moving = g_slist_prepend(*moving, d_add);
 723                 lowest_dragger = d_add;
 724             } else {
 725                 break;
 726             }
 727         }
 728
 729         while ( true )
 730         {
 731             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 732             if ( d_add && g_list_find(drag->selected, d_add) ) {
 733                 highest_i = highest_i + 1;
 734                 *moving = g_slist_append(*moving, d_add);
 735                 highest_dragger = d_add;
 736             } else {
 737                 break;
 738             }
 739         }
 740     }
 741
 742     if ( SP_IS_LINEARGRADIENT(server) ) {
 743         guint num = SP_LINEARGRADIENT(server)->vector.stops.size();
 744         GrDragger *d_temp;
 745         if (lowest_i == 1) {
 746             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke);
 747         } else {
 748             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, lowest_i - 1, draggable->fill_or_stroke);
 749         }
 750         if (d_temp)
 751             *begin = d_temp->point;
 752
 753         d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, highest_i + 1, draggable->fill_or_stroke);
 754         if (d_temp == NULL) {
 755             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_END, num-1, draggable->fill_or_stroke);
 756         }
 757         if (d_temp)
 758             *end = d_temp->point;
 759     } else if ( SP_IS_RADIALGRADIENT(server) ) {
 760         guint num = SP_RADIALGRADIENT(server)->vector.stops.size();
 761         GrDragger *d_temp;
 762         if (lowest_i == 1) {
 763             d_temp = drag->getDraggerFor (draggable->item, POINT_RG_CENTER, 0, draggable->fill_or_stroke);
 764         } else {
 765             d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 766         }
 767         if (d_temp)
 768             *begin = d_temp->point;
 769
 770         d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 771         if (d_temp == NULL) {
 772             d_temp = drag->getDraggerFor (draggable->item, (draggable->point_type==POINT_RG_MID1) ? POINT_RG_R1 : POINT_RG_R2, num-1, draggable->fill_or_stroke);
 773         }
 774         if (d_temp)
 775             *end = d_temp->point;
 776     }
 777
 778     *low_lim  = dragger->point - (lowest_dragger->point - *begin);
 779     *high_lim = dragger->point - (highest_dragger->point - *end);
 780 }
 781
 782
 783
 784 /**
 785 Called when a midpoint knot is dragged.
 786 */
 787 static void
 788 gr_knot_moved_midpoint_handler(SPKnot */*knot*/, Geom::Point const &ppointer, guint state, gpointer data)
 789 {
 790     GrDragger *dragger = (GrDragger *) data;
 791     GrDrag *drag = dragger->parent;
 792     // a midpoint dragger can (logically) only contain one GrDraggable
 793     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 794
 795     // FIXME: take from prefs
 796     double snap_fraction = 0.1;
 797
 798     Geom::Point p = ppointer;
 799     Geom::Point begin(0,0), end(0,0);
 800     Geom::Point low_lim(0,0), high_lim(0,0);
 801
 802     SPObject *server = draggable->getServer();
 803
 804     GSList *moving = NULL;
 805     gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
 806
 807     if (state & GDK_CONTROL_MASK) {
 808         p = snap_vector_midpoint (p, low_lim, high_lim, snap_fraction);
 809     } else {
 810         p = snap_vector_midpoint (p, low_lim, high_lim, 0);
 811         if (!(state & GDK_SHIFT_MASK)) {
 812             SPDesktop *desktop = dragger->parent->desktop;
 813             SnapManager &m = desktop->namedview->snap_manager;
 814             Inkscape::Snapper::ConstraintLine cl(low_lim, high_lim - low_lim);
 815             m.constrainedSnapReturnByRef(p, Inkscape::SNAPSOURCE_OTHER_HANDLE, cl);
 816         }
 817     }
 818     Geom::Point displacement = p - dragger->point;
 819
 820     for (GSList const* i = moving; i != NULL; i = i->next) {
 821         GrDragger *drg = (GrDragger*) i->data;
 822         SPKnot *drgknot = drg->knot;
 823         Geom::Point this_move = displacement;
 824         if (state & GDK_MOD1_MASK) {
 825             // FIXME: unify all these profiles (here, in nodepath, in tweak) in one place
 826             double alpha = 1.0;
 827             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
 828                 double x = Geom::L2(drg->point - dragger->point)/Geom::L2(end - dragger->point);
 829                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 830             } else { // drg is on the begin side from dragger
 831                 double x = Geom::L2(drg->point - dragger->point)/Geom::L2(begin - dragger->point);
 832                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 833             }
 834         }
 835         drg->point += this_move;
 836         sp_knot_moveto (drgknot, drg->point);
 837         drg->fireDraggables (false);
 838         drg->updateDependencies(false);
 839     }
 840
 841     g_slist_free(moving);
 842
 843     drag->keep_selection = dragger->isSelected();
 844 }
 845
 846
 847
 848 static void
 849 gr_knot_grabbed_handler (SPKnot */*knot*/, unsigned int /*state*/, gpointer data)
 850 {
 851     GrDragger *dragger = (GrDragger *) data;
 852
 853     sp_canvas_force_full_redraw_after_interruptions(dragger->parent->desktop->canvas, 5);
 854 }
 855
 856 /**
 857 Called when the mouse releases a dragger knot; changes gradient writing to repr, updates other draggers if needed
 858 */
 859 static void
 860 gr_knot_ungrabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 861 {
 862     GrDragger *dragger = (GrDragger *) data;
 863
 864     sp_canvas_end_forced_full_redraws(dragger->parent->desktop->canvas);
 865
 866     dragger->point_original = dragger->point = knot->pos;
 867
 868     if ((state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK)) {
 869         dragger->fireDraggables (true, true);
 870     } else {
 871         dragger->fireDraggables (true);
 872     }
 873
 874     for (GList *i = dragger->parent->selected; i != NULL; i = i->next) {
 875         GrDragger *d = (GrDragger *) i->data;
 876         if (d == dragger)
 877             continue;
 878         d->fireDraggables (true);
 879     }
 880
 881     // make this dragger selected
 882     if (!dragger->parent->keep_selection) {
 883         dragger->parent->setSelected (dragger);
 884     }
 885     dragger->parent->keep_selection = false;
 886
 887     dragger->updateDependencies(true);
 888
 889     // we did an undoable action
 890     SPDocumentUndo::done (sp_desktop_document (dragger->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 891                       _("Move gradient handle"));
 892 }
 893
 894 /**
 895 Called when a dragger knot is clicked; selects the dragger or deletes it depending on the
 896 state of the keyboard keys
 897 */
 898 static void
 899 gr_knot_clicked_handler(SPKnot */*knot*/, guint state, gpointer data)
 900 {
 901     GrDragger *dragger = (GrDragger *) data;
 902     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 903     if (!draggable) return;
 904
 905     if ( (state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK ) ) {
 906     // delete this knot from vector
 907         SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
 908         gradient = gradient->getVector();
 909         if (gradient->vector.stops.size() > 2) { // 2 is the minimum
 910             SPStop *stop = NULL;
 911             switch (draggable->point_type) {  // if we delete first or last stop, move the next/previous to the edge
 912             case POINT_LG_BEGIN:
 913             case POINT_RG_CENTER:
 914                 stop = gradient->getFirstStop();
 915                 {
 916                     SPStop *next = stop->getNextStop();
 917                     if (next) {
 918                         next->offset = 0;
 919                         sp_repr_set_css_double (SP_OBJECT_REPR (next), "offset", 0);
 920                     }
 921                 }
 922                 break;
 923             case POINT_LG_END:
 924             case POINT_RG_R1:
 925             case POINT_RG_R2:
 926                 stop = sp_last_stop(gradient);
 927                 {
 928                     SPStop *prev = stop->getPrevStop();
 929                     if (prev) {
 930                         prev->offset = 1;
 931                         sp_repr_set_css_double (SP_OBJECT_REPR (prev), "offset", 1);
 932                     }
 933                 }
 934                 break;
 935             case POINT_LG_MID:
 936             case POINT_RG_MID1:
 937             case POINT_RG_MID2:
 938                 stop = sp_get_stop_i(gradient, draggable->point_i);
 939                 break;
 940             }
 941
 942             SP_OBJECT_REPR(gradient)->removeChild(SP_OBJECT_REPR(stop));
 943             SPDocumentUndo::done (SP_OBJECT_DOCUMENT (gradient), SP_VERB_CONTEXT_GRADIENT,
 944                       _("Delete gradient stop"));
 945         }
 946     } else {
 947     // select the dragger
 948         dragger->point_original = dragger->point;
 949
 950         if ( state & GDK_SHIFT_MASK ) {
 951             dragger->parent->setSelected (dragger, true, false);
 952         } else {
 953             dragger->parent->setSelected (dragger);
 954         }
 955     }
 956 }
 957
 958 /**
 959 Called when a dragger knot is doubleclicked; opens gradient editor with the stop from the first draggable
 960 */
 961 static void
 962 gr_knot_doubleclicked_handler (SPKnot */*knot*/, guint /*state*/, gpointer data)
 963 {
 964     GrDragger *dragger = (GrDragger *) data;
 965
 966     dragger->point_original = dragger->point;
 967
 968     if (dragger->draggables == NULL)
 969         return;
 970
 971     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 972     sp_item_gradient_edit_stop (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 973 }
 974
 975 /**
 976 Act upon all draggables of the dragger, setting them to the dragger's point
 977 */
 978 void
 979 GrDragger::fireDraggables (bool write_repr, bool scale_radial, bool merging_focus)
 980 {
 981     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
 982         GrDraggable *draggable = (GrDraggable *) i->data;
 983
 984         // set local_change flag so that selection_changed callback does not regenerate draggers
 985         this->parent->local_change = true;
 986
 987         // change gradient, optionally writing to repr; prevent focus from moving if it's snapped
 988         // to the center, unless it's the first update upon merge when we must snap it to the point
 989         if (merging_focus ||
 990             !(draggable->point_type == POINT_RG_FOCUS && this->isA(draggable->item, POINT_RG_CENTER, draggable->point_i, draggable->fill_or_stroke)))
 991         {
 992             sp_item_gradient_set_coords (draggable->item, draggable->point_type, draggable->point_i, this->point, draggable->fill_or_stroke, write_repr, scale_radial);
 993         }
 994     }
 995 }
 996
 997 /**
 998 Checks if the dragger has a draggable with this point_type
 999  */
1000 bool
1001 GrDragger::isA (gint point_type)
1002 {
1003     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1004         GrDraggable *draggable = (GrDraggable *) i->data;
1005         if (draggable->point_type == point_type) {
1006             return true;
1007         }
1008     }
1009     return false;
1010 }
1011
1012 /**
1013 Checks if the dragger has a draggable with this item, point_type + point_i (number), fill_or_stroke
1014  */
1015 bool
1016 GrDragger::isA (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1017 {
1018     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1019         GrDraggable *draggable = (GrDraggable *) i->data;
1020         if ( (draggable->point_type == point_type) && (draggable->point_i == point_i) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
1021             return true;
1022         }
1023     }
1024     return false;
1025 }
1026
1027 /**
1028 Checks if the dragger has a draggable with this item, point_type, fill_or_stroke
1029  */
1030 bool
1031 GrDragger::isA (SPItem *item, gint point_type, bool fill_or_stroke)
1032 {
1033     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1034         GrDraggable *draggable = (GrDraggable *) i->data;
1035         if ( (draggable->point_type == point_type) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
1036             return true;
1037         }
1038     }
1039     return false;
1040 }
1041
1042 bool
1043 GrDraggable::mayMerge (GrDraggable *da2)
1044 {
1045     if ((this->item == da2->item) && (this->fill_or_stroke == da2->fill_or_stroke)) {
1046         // we must not merge the points of the same gradient!
1047         if (!((this->point_type == POINT_RG_FOCUS && da2->point_type == POINT_RG_CENTER) ||
1048               (this->point_type == POINT_RG_CENTER && da2->point_type == POINT_RG_FOCUS))) {
1049             // except that we can snap center and focus together
1050             return false;
1051         }
1052     }
1053     // disable merging of midpoints.
1054     if ( (this->point_type == POINT_LG_MID) || (da2->point_type == POINT_LG_MID)
1055          || (this->point_type == POINT_RG_MID1) || (da2->point_type == POINT_RG_MID1)
1056          || (this->point_type == POINT_RG_MID2) || (da2->point_type == POINT_RG_MID2) )
1057         return false;
1058
1059     return true;
1060 }
1061
1062 bool
1063 GrDragger::mayMerge (GrDragger *other)
1064 {
1065     if (this == other)
1066         return false;
1067
1068     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
1069         GrDraggable *da1 = (GrDraggable *) i->data;
1070         for (GSList const* j = other->draggables; j != NULL; j = j->next) { // for all draggables of other
1071             GrDraggable *da2 = (GrDraggable *) j->data;
1072             if (!da1->mayMerge(da2))
1073                 return false;
1074         }
1075     }
1076     return true;
1077 }
1078
1079 bool
1080 GrDragger::mayMerge (GrDraggable *da2)
1081 {
1082     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
1083         GrDraggable *da1 = (GrDraggable *) i->data;
1084         if (!da1->mayMerge(da2))
1085             return false;
1086     }
1087     return true;
1088 }
1089
1090 /**
1091 Updates the statusbar tip of the dragger knot, based on its draggables
1092  */
1093 void
1094 GrDragger::updateTip ()
1095 {
1096     if (this->knot && this->knot->tip) {
1097         g_free (this->knot->tip);
1098         this->knot->tip = NULL;
1099     }
1100
1101     if (g_slist_length (this->draggables) == 1) {
1102         GrDraggable *draggable = (GrDraggable *) this->draggables->data;
1103         char *item_desc = draggable->item->description();
1104         switch (draggable->point_type) {
1105             case POINT_LG_MID:
1106             case POINT_RG_MID1:
1107             case POINT_RG_MID2:
1108                 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"),
1109                                                    _(gr_knot_descr[draggable->point_type]),
1110                                                    draggable->point_i,
1111                                                    item_desc,
1112                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
1113                 break;
1114
1115             default:
1116                 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"),
1117                                                    _(gr_knot_descr[draggable->point_type]),
1118                                                    item_desc,
1119                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
1120                 break;
1121         }
1122         g_free(item_desc);
1123     } else if (g_slist_length (draggables) == 2 && isA (POINT_RG_CENTER) && isA (POINT_RG_FOCUS)) {
1124         this->knot->tip = g_strdup_printf (_("Radial gradient <b>center</b> and <b>focus</b>; drag with <b>Shift</b> to separate focus"));
1125     } else {
1126         int length = g_slist_length (this->draggables);
1127         this->knot->tip = g_strdup_printf (ngettext("Gradient point shared by <b>%d</b> gradient; drag with <b>Shift</b> to separate",
1128                                                     "Gradient point shared by <b>%d</b> gradients; drag with <b>Shift</b> to separate",
1129                                                     length),
1130                                            length);
1131     }
1132 }
1133
1134 /**
1135 Adds a draggable to the dragger
1136  */
1137 void
1138 GrDragger::updateKnotShape ()
1139 {
1140     if (!draggables)
1141         return;
1142     GrDraggable *last = (GrDraggable *) g_slist_last(draggables)->data;
1143     g_object_set (G_OBJECT (this->knot->item), "shape", gr_knot_shapes[last->point_type], NULL);
1144 }
1145
1146 /**
1147 Adds a draggable to the dragger
1148  */
1149 void
1150 GrDragger::addDraggable (GrDraggable *draggable)
1151 {
1152     this->draggables = g_slist_prepend (this->draggables, draggable);
1153
1154     this->updateTip();
1155 }
1156
1157
1158 /**
1159 Moves this dragger to the point of the given draggable, acting upon all other draggables
1160  */
1161 void
1162 GrDragger::moveThisToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1163 {
1164     GrDraggable *dr_first = (GrDraggable *) this->draggables->data;
1165     if (!dr_first) return;
1166
1167     this->point = sp_item_gradient_get_coords (dr_first->item, dr_first->point_type, dr_first->point_i, dr_first->fill_or_stroke);
1168     this->point_original = this->point;
1169
1170     sp_knot_moveto (this->knot, this->point);
1171
1172     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1173         GrDraggable *da = (GrDraggable *) i->data;
1174         if ( (da->item == item) &&
1175              (point_type == -1 || da->point_type == point_type) &&
1176              (point_i == -1 || da->point_i == point_i) &&
1177              (da->fill_or_stroke == fill_or_stroke) ) {
1178             continue;
1179         }
1180         sp_item_gradient_set_coords (da->item, da->point_type, da->point_i, this->point, da->fill_or_stroke, write_repr, false);
1181     }
1182     // FIXME: here we should also call this->updateDependencies(write_repr); to propagate updating, but how to prevent loops?
1183 }
1184
1185
1186 /**
1187 Moves all midstop draggables that depend on this one
1188  */
1189 void
1190 GrDragger::updateMidstopDependencies (GrDraggable *draggable, bool write_repr) {
1191     SPObject *server = draggable->getServer();
1192     if (!server)
1193         return;
1194     guint num = SP_GRADIENT(server)->vector.stops.size();
1195     if (num <= 2) return;
1196
1197     if ( SP_IS_LINEARGRADIENT(server) ) {
1198         for ( guint i = 1; i < num - 1; i++ ) {
1199             this->moveOtherToDraggable (draggable->item, POINT_LG_MID, i, draggable->fill_or_stroke, write_repr);
1200         }
1201     } else  if ( SP_IS_RADIALGRADIENT(server) ) {
1202         for ( guint i = 1; i < num - 1; i++ ) {
1203             this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, i, draggable->fill_or_stroke, write_repr);
1204             this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, i, draggable->fill_or_stroke, write_repr);
1205         }
1206     }
1207 }
1208
1209
1210 /**
1211 Moves all draggables that depend on this one
1212  */
1213 void
1214 GrDragger::updateDependencies (bool write_repr)
1215 {
1216     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1217         GrDraggable *draggable = (GrDraggable *) i->data;
1218         switch (draggable->point_type) {
1219             case POINT_LG_BEGIN:
1220                 {
1221                     // the end point is dependent only when dragging with ctrl+shift
1222                     this->moveOtherToDraggable (draggable->item, POINT_LG_END, -1, draggable->fill_or_stroke, write_repr);
1223
1224                     this->updateMidstopDependencies (draggable, write_repr);
1225                 }
1226                 break;
1227             case POINT_LG_END:
1228                 {
1229                     // the begin point is dependent only when dragging with ctrl+shift
1230                     this->moveOtherToDraggable (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke, write_repr);
1231
1232                     this->updateMidstopDependencies (draggable, write_repr);
1233                 }
1234                 break;
1235             case POINT_LG_MID:
1236                 // no other nodes depend on mid points.
1237                 break;
1238             case POINT_RG_R2:
1239                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1240                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1241                 this->updateMidstopDependencies (draggable, write_repr);
1242                 break;
1243             case POINT_RG_R1:
1244                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1245                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1246                 this->updateMidstopDependencies (draggable, write_repr);
1247                 break;
1248             case POINT_RG_CENTER:
1249                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1250                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1251                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1252                 this->updateMidstopDependencies (draggable, write_repr);
1253                 break;
1254             case POINT_RG_FOCUS:
1255                 // nothing can depend on that
1256                 break;
1257             case POINT_RG_MID1:
1258                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, draggable->point_i, draggable->fill_or_stroke, write_repr);
1259                 break;
1260             case POINT_RG_MID2:
1261                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, draggable->point_i, draggable->fill_or_stroke, write_repr);
1262                 break;
1263             default:
1264                 break;
1265         }
1266     }
1267 }
1268
1269
1270
1271 GrDragger::GrDragger (GrDrag *parent, Geom::Point p, GrDraggable *draggable)
1272   : point(p),
1273     point_original(p)
1274 {
1275     this->draggables = NULL;
1276
1277     this->parent = parent;
1278
1279     // create the knot
1280     this->knot = sp_knot_new (parent->desktop, NULL);
1281     this->knot->setMode(SP_KNOT_MODE_XOR);
1282     this->knot->setFill(GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_MOUSEOVER, GR_KNOT_COLOR_MOUSEOVER);
1283     this->knot->setStroke(0x0000007f, 0x0000007f, 0x0000007f);
1284     sp_knot_update_ctrl(this->knot);
1285
1286     // move knot to the given point
1287     sp_knot_set_position (this->knot, p, SP_KNOT_STATE_NORMAL);
1288     sp_knot_show (this->knot);
1289
1290     // connect knot's signals
1291     if ( (draggable)  // it can be NULL if a node in unsnapped (eg. focus point unsnapped from center)
1292                        // luckily, midstops never snap to other nodes so are never unsnapped...
1293          && ( (draggable->point_type == POINT_LG_MID)
1294               || (draggable->point_type == POINT_RG_MID1)
1295               || (draggable->point_type == POINT_RG_MID2) ) )
1296     {
1297         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_midpoint_handler), this);
1298     } else {
1299         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_handler), this);
1300     }
1301     g_signal_connect (G_OBJECT (this->knot), "clicked", G_CALLBACK (gr_knot_clicked_handler), this);
1302     g_signal_connect (G_OBJECT (this->knot), "doubleclicked", G_CALLBACK (gr_knot_doubleclicked_handler), this);
1303     g_signal_connect (G_OBJECT (this->knot), "grabbed", G_CALLBACK (gr_knot_grabbed_handler), this);
1304     g_signal_connect (G_OBJECT (this->knot), "ungrabbed", G_CALLBACK (gr_knot_ungrabbed_handler), this);
1305
1306     // add the initial draggable
1307     if (draggable)
1308         this->addDraggable (draggable);
1309     updateKnotShape();
1310 }
1311
1312 GrDragger::~GrDragger ()
1313 {
1314     // unselect if it was selected
1315     this->parent->setDeselected(this);
1316
1317     // disconnect signals
1318     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_moved_handler), this);
1319     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_clicked_handler), this);
1320     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_doubleclicked_handler), this);
1321     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_grabbed_handler), this);
1322     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_ungrabbed_handler), this);
1323
1324     /* unref should call destroy */
1325     g_object_unref (G_OBJECT (this->knot));
1326
1327     // delete all draggables
1328     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1329         delete ((GrDraggable *) i->data);
1330     }
1331     g_slist_free (this->draggables);
1332     this->draggables = NULL;
1333 }
1334
1335 /**
1336 Select the dragger which has the given draggable.
1337 */
1338 GrDragger *
1339 GrDrag::getDraggerFor (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1340 {
1341     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1342         GrDragger *dragger = (GrDragger *) i->data;
1343         for (GSList const* j = dragger->draggables; j != NULL; j = j->next) {
1344             GrDraggable *da2 = (GrDraggable *) j->data;
1345             if ( (da2->item == item) &&
1346                  (point_type == -1 || da2->point_type == point_type) && // -1 means this does not matter
1347                  (point_i == -1 || da2->point_i == point_i) && // -1 means this does not matter
1348                  (da2->fill_or_stroke == fill_or_stroke)) {
1349                 return (dragger);
1350             }
1351         }
1352     }
1353     return NULL;
1354 }
1355
1356
1357 void
1358 GrDragger::moveOtherToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1359 {
1360     GrDragger *d = this->parent->getDraggerFor (item, point_type, point_i, fill_or_stroke);
1361     if (d && d !=  this) {
1362         d->moveThisToDraggable (item, point_type, point_i, fill_or_stroke, write_repr);
1363     }
1364 }
1365
1366
1367 /**
1368   Draw this dragger as selected
1369 */
1370 void
1371 GrDragger::select()
1372 {
1373     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_SELECTED;
1374     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_SELECTED, NULL);
1375 }
1376
1377 /**
1378   Draw this dragger as normal (deselected)
1379 */
1380 void
1381 GrDragger::deselect()
1382 {
1383     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_NORMAL;
1384     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_NORMAL, NULL);
1385 }
1386
1387 bool
1388 GrDragger::isSelected()
1389 {
1390     return g_list_find (parent->selected, this);
1391 }
1392
1393 /**
1394 \brief Deselect all stops/draggers (private)
1395 */
1396 void
1397 GrDrag::deselect_all()
1398 {
1399     while (selected) {
1400         ( (GrDragger*) selected->data)->deselect();
1401         selected = g_list_remove(selected, selected->data);
1402     }
1403 }
1404
1405 /**
1406 \brief Deselect all stops/draggers (public; emits signal)
1407 */
1408 void
1409 GrDrag::deselectAll()
1410 {
1411     deselect_all();
1412     this->desktop->emitToolSubselectionChanged(NULL);
1413 }
1414
1415 /**
1416 \brief Select all stops/draggers
1417 */
1418 void
1419 GrDrag::selectAll()
1420 {
1421     for (GList *l = this->draggers; l != NULL; l = l->next) {
1422         GrDragger *d = ((GrDragger *) l->data);
1423         setSelected (d, true, true);
1424     }
1425 }
1426
1427 /**
1428 \brief Select all stops/draggers that match the coords
1429 */
1430 void
1431 GrDrag::selectByCoords(std::vector<Geom::Point> coords)
1432 {
1433     for (GList *l = this->draggers; l != NULL; l = l->next) {
1434         GrDragger *d = ((GrDragger *) l->data);
1435         for (guint k = 0; k < coords.size(); k++) {
1436             if (Geom::L2 (d->point - coords[k]) < 1e-4) {
1437                 setSelected (d, true, true);
1438             }
1439         }
1440     }
1441 }
1442
1443
1444 /**
1445 \brief Select all stops/draggers that fall within the rect
1446 */
1447 void
1448 GrDrag::selectRect(Geom::Rect const &r)
1449 {
1450     for (GList *l = this->draggers; l != NULL; l = l->next) {
1451         GrDragger *d = ((GrDragger *) l->data);
1452         if (r.contains(d->point)) {
1453            setSelected (d, true, true);
1454         }
1455     }
1456 }
1457
1458 /**
1459 \brief Select a dragger
1460 \param dragger       The dragger to select
1461 \param add_to_selection   If true, add to selection, otherwise deselect others
1462 \param override      If true, always select this node, otherwise toggle selected status
1463 */
1464 void
1465 GrDrag::setSelected (GrDragger *dragger, bool add_to_selection, bool override)
1466 {
1467     GrDragger *seldragger = NULL;
1468
1469     if (add_to_selection) {
1470         if (!dragger) return;
1471         if (override) {
1472             if (!g_list_find(selected, dragger)) {
1473                 selected = g_list_prepend(selected, dragger);
1474             }
1475             dragger->select();
1476             seldragger = dragger;
1477         } else { // toggle
1478             if (g_list_find(selected, dragger)) {
1479                 selected = g_list_remove(selected, dragger);
1480                 dragger->deselect();
1481                 if (selected) {
1482                     seldragger = (GrDragger*) selected->data; // select the dragger that is first in the list
1483                 }
1484             } else {
1485                 selected = g_list_prepend(selected, dragger);
1486                 dragger->select();
1487                 seldragger = dragger;
1488             }
1489         }
1490     } else {
1491         deselect_all();
1492         if (dragger) {
1493             selected = g_list_prepend(selected, dragger);
1494             dragger->select();
1495             seldragger = dragger;
1496         }
1497     }
1498     if (seldragger) {
1499         this->desktop->emitToolSubselectionChanged((gpointer) seldragger);
1500     }
1501 }
1502
1503 /**
1504 \brief Deselect a dragger
1505 \param dragger       The dragger to deselect
1506 */
1507 void
1508 GrDrag::setDeselected (GrDragger *dragger)
1509 {
1510     if (g_list_find(selected, dragger)) {
1511         selected = g_list_remove(selected, dragger);
1512         dragger->deselect();
1513     }
1514     this->desktop->emitToolSubselectionChanged((gpointer) (selected ? selected->data : NULL ));
1515 }
1516
1517
1518
1519 /**
1520 Create a line from p1 to p2 and add it to the lines list
1521  */
1522 void
1523 GrDrag::addLine (SPItem *item, Geom::Point p1, Geom::Point p2, guint32 rgba)
1524 {
1525     SPCanvasItem *line = sp_canvas_item_new(sp_desktop_controls(this->desktop),
1526                                                             SP_TYPE_CTRLLINE, NULL);
1527     sp_canvas_item_move_to_z(line, 0);
1528     SP_CTRLLINE(line)->item = item;
1529     sp_ctrlline_set_coords(SP_CTRLLINE(line), p1, p2);
1530     if (rgba != GR_LINE_COLOR_FILL) // fill is the default, so don't set color for it to speed up redraw
1531         sp_ctrlline_set_rgba32 (SP_CTRLLINE(line), rgba);
1532     sp_canvas_item_show (line);
1533     this->lines = g_slist_append (this->lines, line);
1534 }
1535
1536 /**
1537 If there already exists a dragger within MERGE_DIST of p, add the draggable to it; otherwise create
1538 new dragger and add it to draggers list
1539  */
1540 void
1541 GrDrag::addDragger (GrDraggable *draggable)
1542 {
1543     Geom::Point p = sp_item_gradient_get_coords (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
1544
1545     for (GList *i = this->draggers; i != NULL; i = i->next) {
1546         GrDragger *dragger = (GrDragger *) i->data;
1547         if (dragger->mayMerge (draggable) && Geom::L2 (dragger->point - p) < MERGE_DIST) {
1548             // distance is small, merge this draggable into dragger, no need to create new dragger
1549             dragger->addDraggable (draggable);
1550             dragger->updateKnotShape();
1551             return;
1552         }
1553     }
1554
1555     GrDragger *new_dragger = new GrDragger(this, p, draggable);
1556     // fixme: draggers should be added AFTER the last one: this way tabbing through them will be from begin to end.
1557     this->draggers = g_list_append (this->draggers, new_dragger);
1558 }
1559
1560 /**
1561 Add draggers for the radial gradient rg on item
1562 */
1563 void
1564 GrDrag::addDraggersRadial (SPRadialGradient *rg, SPItem *item, bool fill_or_stroke)
1565 {
1566     addDragger (new GrDraggable (item, POINT_RG_CENTER, 0, fill_or_stroke));
1567     guint num = rg->vector.stops.size();
1568     if (num > 2) {
1569         for ( guint i = 1; i < num - 1; i++ ) {
1570             addDragger (new GrDraggable (item, POINT_RG_MID1, i, fill_or_stroke));
1571         }
1572     }
1573     addDragger (new GrDraggable (item, POINT_RG_R1, num-1, fill_or_stroke));
1574     if (num > 2) {
1575         for ( guint i = 1; i < num - 1; i++ ) {
1576             addDragger (new GrDraggable (item, POINT_RG_MID2, i, fill_or_stroke));
1577         }
1578     }
1579     addDragger (new GrDraggable (item, POINT_RG_R2, num-1, fill_or_stroke));
1580     addDragger (new GrDraggable (item, POINT_RG_FOCUS, 0, fill_or_stroke));
1581 }
1582
1583 /**
1584 Add draggers for the linear gradient lg on item
1585 */
1586 void
1587 GrDrag::addDraggersLinear (SPLinearGradient *lg, SPItem *item, bool fill_or_stroke)
1588 {
1589     addDragger (new GrDraggable (item, POINT_LG_BEGIN, 0, fill_or_stroke));
1590     guint num = lg->vector.stops.size();
1591     if (num > 2) {
1592         for ( guint i = 1; i < num - 1; i++ ) {
1593             addDragger (new GrDraggable (item, POINT_LG_MID, i, fill_or_stroke));
1594         }
1595     }
1596     addDragger (new GrDraggable (item, POINT_LG_END, num-1, fill_or_stroke));
1597 }
1598
1599 /**
1600 Artificially grab the knot of this dragger; used by the gradient context
1601 */
1602 void
1603 GrDrag::grabKnot (GrDragger *dragger, gint x, gint y, guint32 etime)
1604 {
1605     if (dragger) {
1606         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1607     }
1608 }
1609
1610 /**
1611 Artificially grab the knot of the dragger with this draggable; used by the gradient context
1612 */
1613 void
1614 GrDrag::grabKnot (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, gint x, gint y, guint32 etime)
1615 {
1616     GrDragger *dragger = getDraggerFor (item, point_type, point_i, fill_or_stroke);
1617     if (dragger) {
1618         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1619     }
1620 }
1621
1622 /**
1623 Regenerates the draggers list from the current selection; is called when selection is changed or
1624 modified, also when a radial dragger needs to update positions of other draggers in the gradient
1625 */
1626 void
1627 GrDrag::updateDraggers ()
1628 {
1629     while (selected) {
1630         selected = g_list_remove(selected, selected->data);
1631     }
1632     // delete old draggers
1633     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1634         delete ((GrDragger *) i->data);
1635     }
1636     g_list_free (this->draggers);
1637     this->draggers = NULL;
1638
1639     g_return_if_fail (this->selection != NULL);
1640
1641     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1642
1643         SPItem *item = SP_ITEM(i->data);
1644         SPStyle *style = SP_OBJECT_STYLE (item);
1645
1646         if (style && (style->fill.isPaintserver())) {
1647             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1648             if (SP_IS_LINEARGRADIENT (server)) {
1649                 addDraggersLinear (SP_LINEARGRADIENT (server), item, true);
1650             } else if (SP_IS_RADIALGRADIENT (server)) {
1651                 addDraggersRadial (SP_RADIALGRADIENT (server), item, true);
1652             }
1653         }
1654
1655         if (style && (style->stroke.isPaintserver())) {
1656             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1657             if (SP_IS_LINEARGRADIENT (server)) {
1658                 addDraggersLinear (SP_LINEARGRADIENT (server), item, false);
1659             } else if (SP_IS_RADIALGRADIENT (server)) {
1660                 addDraggersRadial (SP_RADIALGRADIENT (server), item, false);
1661             }
1662         }
1663     }
1664 }
1665
1666
1667 /**
1668  * \brief Returns true if at least one of the draggers' knots has the mouse hovering above it
1669  */
1670
1671 bool
1672 GrDrag::mouseOver()
1673 {
1674     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1675         GrDragger *d = (GrDragger *) i->data;
1676         if (d->knot && (d->knot->flags & SP_KNOT_MOUSEOVER)) {
1677             return true;
1678         }
1679     }
1680     return false;
1681 }
1682 /**
1683 Regenerates the lines list from the current selection; is called on each move of a dragger, so that
1684 lines are always in sync with the actual gradient
1685 */
1686 void
1687 GrDrag::updateLines ()
1688 {
1689     // delete old lines
1690     for (GSList const *i = this->lines; i != NULL; i = i->next) {
1691         gtk_object_destroy( GTK_OBJECT (i->data));
1692     }
1693     g_slist_free (this->lines);
1694     this->lines = NULL;
1695
1696     g_return_if_fail (this->selection != NULL);
1697
1698     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1699
1700         SPItem *item = SP_ITEM(i->data);
1701
1702         SPStyle *style = SP_OBJECT_STYLE (item);
1703
1704         if (style && (style->fill.isPaintserver())) {
1705             SPObject *server = SP_OBJECT_STYLE_FILL_SERVER (item);
1706             if (SP_IS_LINEARGRADIENT (server)) {
1707                 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);
1708             } else if (SP_IS_RADIALGRADIENT (server)) {
1709                 Geom::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, true);
1710                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, true), GR_LINE_COLOR_FILL);
1711                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, true), GR_LINE_COLOR_FILL);
1712             }
1713         }
1714
1715         if (style && (style->stroke.isPaintserver())) {
1716             SPObject *server = SP_OBJECT_STYLE_STROKE_SERVER (item);
1717             if (SP_IS_LINEARGRADIENT (server)) {
1718                 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);
1719             } else if (SP_IS_RADIALGRADIENT (server)) {
1720                 Geom::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, false);
1721                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, false), GR_LINE_COLOR_STROKE);
1722                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, false), GR_LINE_COLOR_STROKE);
1723             }
1724         }
1725     }
1726 }
1727
1728 /**
1729 Regenerates the levels list from the current selection
1730 */
1731 void
1732 GrDrag::updateLevels ()
1733 {
1734     hor_levels.clear();
1735     vert_levels.clear();
1736
1737     g_return_if_fail (this->selection != NULL);
1738
1739     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1740         SPItem *item = SP_ITEM(i->data);
1741         Geom::OptRect rect = item->getBboxDesktop ();
1742         if (rect) {
1743             // Remember the edges of the bbox and the center axis
1744             hor_levels.push_back(rect->min()[Geom::Y]);
1745             hor_levels.push_back(rect->max()[Geom::Y]);
1746             hor_levels.push_back(0.5 * (rect->min()[Geom::Y] + rect->max()[Geom::Y]));
1747             vert_levels.push_back(rect->min()[Geom::X]);
1748             vert_levels.push_back(rect->max()[Geom::X]);
1749             vert_levels.push_back(0.5 * (rect->min()[Geom::X] + rect->max()[Geom::X]));
1750         }
1751     }
1752 }
1753
1754 void
1755 GrDrag::selected_reverse_vector ()
1756 {
1757     if (selected == NULL)
1758         return;
1759
1760     for (GSList const* i = ( (GrDragger*) selected->data )->draggables; i != NULL; i = i->next) {
1761         GrDraggable *draggable = (GrDraggable *) i->data;
1762
1763         sp_item_gradient_reverse_vector (draggable->item, draggable->fill_or_stroke);
1764     }
1765 }
1766
1767 void
1768 GrDrag::selected_move_nowrite (double x, double y, bool scale_radial)
1769 {
1770     selected_move (x, y, false, scale_radial);
1771 }
1772
1773 void
1774 GrDrag::selected_move (double x, double y, bool write_repr, bool scale_radial)
1775 {
1776     if (selected == NULL)
1777         return;
1778
1779     bool did = false;
1780
1781     for (GList *i = selected; i != NULL; i = i->next) {
1782         GrDragger *d = (GrDragger *) i->data;
1783
1784         if (!d->isA(POINT_LG_MID) && !d->isA(POINT_RG_MID1) && !d->isA(POINT_RG_MID2)) {
1785             // if this is an endpoint,
1786
1787             // Moving an rg center moves its focus and radii as well.
1788             // therefore, if this is a focus or radius and if selection
1789             // contains the center as well, do not move this one
1790             if (d->isA(POINT_RG_R1) || d->isA(POINT_RG_R2) ||
1791                 (d->isA(POINT_RG_FOCUS) && !d->isA(POINT_RG_CENTER))) {
1792                 bool skip_radius_with_center = false;
1793                 for (GList *di = selected; di != NULL; di = di->next) {
1794                     GrDragger *d_new = (GrDragger *) di->data;
1795                     if (d_new->isA (((GrDraggable *) d->draggables->data)->item,
1796                                     POINT_RG_CENTER,
1797                                     0,
1798                                     ((GrDraggable *) d->draggables->data)->fill_or_stroke)) {
1799                         // FIXME: here we take into account only the first draggable!
1800                         skip_radius_with_center = true;
1801                     }
1802                 }
1803                 if (skip_radius_with_center)
1804                     continue;
1805             }
1806
1807             did = true;
1808             d->point += Geom::Point (x, y);
1809             d->point_original = d->point;
1810             sp_knot_moveto (d->knot, d->point);
1811
1812             d->fireDraggables (write_repr, scale_radial);
1813
1814             d->updateDependencies(write_repr);
1815         }
1816     }
1817
1818     if (write_repr && did) {
1819         // we did an undoable action
1820         SPDocumentUndo::maybe_done (sp_desktop_document (desktop), "grmoveh", SP_VERB_CONTEXT_GRADIENT,
1821                                 _("Move gradient handle(s)"));
1822         return;
1823     }
1824
1825     if (!did) { // none of the end draggers are selected, so let's try to move the mids
1826
1827         GrDragger *dragger = (GrDragger *) selected->data;
1828         // a midpoint dragger can (logically) only contain one GrDraggable
1829         GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
1830
1831         Geom::Point begin(0,0), end(0,0);
1832         Geom::Point low_lim(0,0), high_lim(0,0);
1833
1834         SPObject *server = draggable->getServer();
1835         GSList *moving = NULL;
1836         gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
1837
1838         Geom::Point p(x, y);
1839         p = snap_vector_midpoint (dragger->point + p, low_lim, high_lim, 0);
1840         Geom::Point displacement = p - dragger->point;
1841
1842         for (GSList const* i = moving; i != NULL; i = i->next) {
1843             GrDragger *drg = (GrDragger*) i->data;
1844             SPKnot *drgknot = drg->knot;
1845             drg->point += displacement;
1846             sp_knot_moveto (drgknot, drg->point);
1847             drg->fireDraggables (true);
1848             drg->updateDependencies(true);
1849             did = true;
1850         }
1851
1852         g_slist_free(moving);
1853
1854         if (write_repr && did) {
1855             // we did an undoable action
1856             SPDocumentUndo::maybe_done (sp_desktop_document (desktop), "grmovem", SP_VERB_CONTEXT_GRADIENT,
1857                                     _("Move gradient mid stop(s)"));
1858         }
1859     }
1860 }
1861
1862 void
1863 GrDrag::selected_move_screen (double x, double y)
1864 {
1865     gdouble zoom = desktop->current_zoom();
1866     gdouble zx = x / zoom;
1867     gdouble zy = y / zoom;
1868
1869     selected_move (zx, zy);
1870 }
1871
1872 /**
1873 Select the knot next to the last selected one and deselect all other selected.
1874 */
1875 GrDragger *
1876 GrDrag::select_next ()
1877 {
1878     GrDragger *d = NULL;
1879     if (selected == NULL || g_list_find(draggers, selected->data)->next == NULL) {
1880         if (draggers)
1881             d = (GrDragger *) draggers->data;
1882     } else {
1883         d = (GrDragger *) g_list_find(draggers, selected->data)->next->data;
1884     }
1885     if (d)
1886         setSelected (d);
1887     return d;
1888 }
1889
1890 /**
1891 Select the knot previous from the last selected one and deselect all other selected.
1892 */
1893 GrDragger *
1894 GrDrag::select_prev ()
1895 {
1896     GrDragger *d = NULL;
1897     if (selected == NULL || g_list_find(draggers, selected->data)->prev == NULL) {
1898         if (draggers)
1899             d = (GrDragger *) g_list_last (draggers)->data;
1900     } else {
1901         d = (GrDragger *) g_list_find(draggers, selected->data)->prev->data;
1902     }
1903     if (d)
1904         setSelected (d);
1905     return d;
1906 }
1907
1908
1909 // FIXME: i.m.o. an ugly function that I just made to work, but... aargh! (Johan)
1910 void
1911 GrDrag::deleteSelected (bool just_one)
1912 {
1913     if (!selected) return;
1914
1915     SPDocument *document = false;
1916
1917     struct StructStopInfo {
1918         SPStop * spstop;
1919         GrDraggable * draggable;
1920         SPGradient * gradient;
1921         SPGradient * vector;
1922     };
1923
1924     GSList *midstoplist = NULL;  // list of stops that must be deleted (will be deleted first)
1925     GSList *endstoplist = NULL;  // list of stops that must be deleted
1926     while (selected) {
1927         GrDragger *dragger = (GrDragger*) selected->data;
1928         for (GSList * drgble = dragger->draggables; drgble != NULL; drgble = drgble->next) {
1929             GrDraggable *draggable = (GrDraggable*) drgble->data;
1930             SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
1931             SPGradient *vector   = sp_gradient_get_forked_vector_if_necessary (gradient, false);
1932
1933             switch (draggable->point_type) {
1934                 case POINT_LG_MID:
1935                 case POINT_RG_MID1:
1936                 case POINT_RG_MID2:
1937                     {
1938                         SPStop *stop = sp_get_stop_i(vector, draggable->point_i);
1939                         // check if already present in list. (e.g. when both RG_MID1 and RG_MID2 were selected)
1940                         bool present = false;
1941                         for (GSList const * l = midstoplist; l != NULL; l = l->next) {
1942                             if ( (SPStop*)l->data == stop ) {
1943                                 present = true;
1944                                 break; // no need to search further.
1945                             }
1946                         }
1947                         if (!present)
1948                             midstoplist = g_slist_append(midstoplist, stop);
1949                     }
1950                     break;
1951                 case POINT_LG_BEGIN:
1952                 case POINT_LG_END:
1953                 case POINT_RG_CENTER:
1954                 case POINT_RG_R1:
1955                 case POINT_RG_R2:
1956                     {
1957                         SPStop *stop = NULL;
1958                         if ( (draggable->point_type == POINT_LG_BEGIN) || (draggable->point_type == POINT_RG_CENTER) ) {
1959                             stop = vector->getFirstStop();
1960                         } else {
1961                             stop = sp_last_stop(vector);
1962                         }
1963                         if (stop) {
1964                             StructStopInfo *stopinfo = new StructStopInfo;
1965                             stopinfo->spstop = stop;
1966                             stopinfo->draggable = draggable;
1967                             stopinfo->gradient = gradient;
1968                             stopinfo->vector = vector;
1969                             // check if already present in list. (e.g. when both R1 and R2 were selected)
1970                             bool present = false;
1971                             for (GSList const * l = endstoplist; l != NULL; l = l->next) {
1972                                 if ( ((StructStopInfo*)l->data)->spstop == stopinfo->spstop ) {
1973                                     present = true;
1974                                     break; // no need to search further.
1975                                 }
1976                             }
1977                             if (!present)
1978                                 endstoplist = g_slist_append(endstoplist, stopinfo);
1979                         }
1980                     }
1981                     break;
1982                 default:
1983                     break;
1984             }
1985         }
1986         selected = g_list_remove(selected, dragger);
1987         if ( just_one ) break; // iterate once if just_one is set.
1988     }
1989     while (midstoplist) {
1990         SPStop *stop = (SPStop*) midstoplist->data;
1991         document = SP_OBJECT_DOCUMENT (stop);
1992         Inkscape::XML::Node * parent = SP_OBJECT_REPR(stop)->parent();
1993         parent->removeChild(SP_OBJECT_REPR(stop));
1994         midstoplist = g_slist_remove(midstoplist, stop);
1995     }
1996     while (endstoplist) {
1997         StructStopInfo *stopinfo  = (StructStopInfo*) endstoplist->data;
1998         document = SP_OBJECT_DOCUMENT (stopinfo->spstop);
1999
2000         // 2 is the minimum, cannot delete more than that without deleting the whole vector
2001         // cannot use vector->vector.stops.size() because the vector might be invalidated by deletion of a midstop
2002         // manually count the children, don't know if there already exists a function for this...
2003         int len = 0;
2004         for ( SPObject *child = (stopinfo->vector)->first_child() ;
2005               child != NULL ;
2006               child = SP_OBJECT_NEXT(child) )
2007         {
2008             if ( SP_IS_STOP(child) )  len ++;
2009         }
2010         if (len > 2)
2011         {
2012             switch (stopinfo->draggable->point_type) {
2013                 case POINT_LG_BEGIN:
2014                     {
2015                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2016
2017                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
2018                         Geom::Point oldbegin = Geom::Point (lg->x1.computed, lg->y1.computed);
2019                         Geom::Point end = Geom::Point (lg->x2.computed, lg->y2.computed);
2020                         SPStop *stop = stopinfo->vector->getFirstStop();
2021                         gdouble offset = stop->offset;
2022                         Geom::Point newbegin = oldbegin + offset * (end - oldbegin);
2023                         lg->x1.computed = newbegin[Geom::X];
2024                         lg->y1.computed = newbegin[Geom::Y];
2025
2026                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
2027                         sp_repr_set_svg_double(repr, "x1", lg->x1.computed);
2028                         sp_repr_set_svg_double(repr, "y1", lg->y1.computed);
2029                         stop->offset = 0;
2030                         sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", 0);
2031
2032                         // iterate through midstops to set new offset values such that they won't move on canvas.
2033                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2034                         stop = stop->getNextStop();
2035                         while ( stop != laststop ) {
2036                             stop->offset = (stop->offset - offset)/(1 - offset);
2037                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2038                             stop = stop->getNextStop();
2039                         }
2040                     }
2041                     break;
2042                 case POINT_LG_END:
2043                     {
2044                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2045
2046                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
2047                         Geom::Point begin = Geom::Point (lg->x1.computed, lg->y1.computed);
2048                         Geom::Point oldend = Geom::Point (lg->x2.computed, lg->y2.computed);
2049                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2050                         gdouble offset = laststop->offset;
2051                         Geom::Point newend = begin + offset * (oldend - begin);
2052                         lg->x2.computed = newend[Geom::X];
2053                         lg->y2.computed = newend[Geom::Y];
2054
2055                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
2056                         sp_repr_set_svg_double(repr, "x2", lg->x2.computed);
2057                         sp_repr_set_svg_double(repr, "y2", lg->y2.computed);
2058                         laststop->offset = 1;
2059                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
2060
2061                         // iterate through midstops to set new offset values such that they won't move on canvas.
2062                         SPStop *stop = stopinfo->vector->getFirstStop();
2063                         stop = stop->getNextStop();
2064                         while ( stop != laststop ) {
2065                             stop->offset = stop->offset / offset;
2066                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2067                             stop = stop->getNextStop();
2068                         }
2069                     }
2070                     break;
2071                 case POINT_RG_CENTER:
2072                     {
2073                         SPStop *newfirst = stopinfo->spstop->getNextStop();
2074                         if (newfirst) {
2075                             newfirst->offset = 0;
2076                             sp_repr_set_css_double (SP_OBJECT_REPR (newfirst), "offset", 0);
2077                         }
2078                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2079                     }
2080                     break;
2081                 case POINT_RG_R1:
2082                 case POINT_RG_R2:
2083                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2084
2085                         SPRadialGradient *rg = SP_RADIALGRADIENT(stopinfo->gradient);
2086                         double oldradius = rg->r.computed;
2087                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2088                         gdouble offset = laststop->offset;
2089                         double newradius = offset * oldradius;
2090                         rg->r.computed = newradius;
2091
2092                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(rg);
2093                         sp_repr_set_svg_double(repr, "r", rg->r.computed);
2094                         laststop->offset = 1;
2095                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
2096
2097                         // iterate through midstops to set new offset values such that they won't move on canvas.
2098                         SPStop *stop = stopinfo->vector->getFirstStop();
2099                         stop = stop->getNextStop();
2100                         while ( stop != laststop ) {
2101                             stop->offset = stop->offset / offset;
2102                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2103                             stop = stop->getNextStop();
2104                         }
2105                         break;
2106             }
2107         }
2108         else
2109         { // delete the gradient from the object. set fill to unset  FIXME: set to fill of unselected node?
2110             SPCSSAttr *css = sp_repr_css_attr_new ();
2111
2112             // stopinfo->spstop is the selected stop
2113             Inkscape::XML::Node *unselectedrepr = SP_OBJECT_REPR(stopinfo->vector)->firstChild();
2114             if (unselectedrepr == SP_OBJECT_REPR(stopinfo->spstop) ) {
2115                 unselectedrepr = unselectedrepr->next();
2116             }
2117
2118             if (unselectedrepr == NULL) {
2119                 if (stopinfo->draggable->fill_or_stroke) {
2120                     sp_repr_css_unset_property (css, "fill");
2121                 } else {
2122                     sp_repr_css_unset_property (css, "stroke");
2123                 }
2124             } else {
2125                 SPCSSAttr *stopcss = sp_repr_css_attr(unselectedrepr, "style");
2126                 if (stopinfo->draggable->fill_or_stroke) {
2127                     sp_repr_css_set_property(css, "fill", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
2128                     sp_repr_css_set_property(css, "fill-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
2129                 } else {
2130                     sp_repr_css_set_property(css, "stroke", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
2131                     sp_repr_css_set_property(css, "stroke-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
2132                 }
2133                 sp_repr_css_attr_unref (stopcss);
2134             }
2135
2136             sp_repr_css_change (SP_OBJECT_REPR (stopinfo->draggable->item), css, "style");
2137             sp_repr_css_attr_unref (css);
2138         }
2139
2140         endstoplist = g_slist_remove(endstoplist, stopinfo);
2141         delete stopinfo;
2142     }
2143
2144     if (document) {
2145         SPDocumentUndo::done ( document, SP_VERB_CONTEXT_GRADIENT, _("Delete gradient stop(s)") );
2146     }
2147 }
2148
2149
2150 /*
2151   Local Variables:
2152   mode:c++
2153   c-file-style:"stroustrup"
2154   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
2155   indent-tabs-mode:nil
2156   fill-column:99
2157   End:
2158 */
2159 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :