src/gradient-drag.cpp

   1 /*
   2  * On-canvas gradient dragging
   3  *
   4  * Authors:
   5  *   bulia byak <buliabyak@users.sf.net>
   6  *   Johan Engelen <j.b.c.engelen@ewi.utwente.nl>
   7  *   Jon A. Cruz <jon@joncruz.org>
   8  *
   9  * Copyright (C) 2007 Johan Engelen
  10  * Copyright (C) 2005,2010 Authors
  11  *
  12  * Released under GNU GPL, read the file 'COPYING' for more information
  13  */
  14
  15 #ifdef HAVE_CONFIG_H
  16 #include "config.h"
  17 #endif
  18
  19 #include <glibmm/i18n.h>
  20 #include <cstring>
  21 #include <string>
  22
  23 #include "desktop-handles.h"
  24 #include "selection.h"
  25 #include "desktop.h"
  26 #include "desktop-style.h"
  27 #include "document.h"
  28 #include "display/sp-ctrlline.h"
  29 #include "display/sp-canvas-util.h"
  30 #include "xml/repr.h"
  31 #include "svg/css-ostringstream.h"
  32 #include "svg/svg.h"
  33 #include "libnr/nr-point-fns.h"
  34 #include "preferences.h"
  35 #include "sp-item.h"
  36 #include "style.h"
  37 #include "knot.h"
  38 #include "sp-linear-gradient.h"
  39 #include "sp-radial-gradient.h"
  40 #include "gradient-chemistry.h"
  41 #include "gradient-drag.h"
  42 #include "sp-stop.h"
  43 #include "snap.h"
  44 #include "sp-namedview.h"
  45 #include "selection-chemistry.h"
  46
  47 #define GR_KNOT_COLOR_NORMAL 0xffffff00
  48 #define GR_KNOT_COLOR_MOUSEOVER 0xff000000
  49 #define GR_KNOT_COLOR_SELECTED 0x0000ff00
  50
  51 #define GR_LINE_COLOR_FILL 0x0000ff7f
  52 #define GR_LINE_COLOR_STROKE 0x9999007f
  53
  54 // screen pixels between knots when they snap:
  55 #define SNAP_DIST 5
  56
  57 // absolute distance between gradient points for them to become a single dragger when the drag is created:
  58 #define MERGE_DIST 0.1
  59
  60 // knot shapes corresponding to GrPointType enum
  61 SPKnotShapeType gr_knot_shapes [] = {
  62         SP_KNOT_SHAPE_SQUARE, //POINT_LG_BEGIN
  63         SP_KNOT_SHAPE_CIRCLE,  //POINT_LG_END
  64         SP_KNOT_SHAPE_DIAMOND, //POINT_LG_MID
  65         SP_KNOT_SHAPE_SQUARE,  // POINT_RG_CENTER
  66         SP_KNOT_SHAPE_CIRCLE,  // POINT_RG_R1
  67         SP_KNOT_SHAPE_CIRCLE,  // POINT_RG_R2
  68         SP_KNOT_SHAPE_CROSS, // POINT_RG_FOCUS
  69         SP_KNOT_SHAPE_DIAMOND, //POINT_RG_MID1
  70         SP_KNOT_SHAPE_DIAMOND //POINT_RG_MID2
  71 };
  72
  73 const gchar *gr_knot_descr [] = {
  74     N_("Linear gradient <b>start</b>"), //POINT_LG_BEGIN
  75     N_("Linear gradient <b>end</b>"),
  76     N_("Linear gradient <b>mid stop</b>"),
  77     N_("Radial gradient <b>center</b>"),
  78     N_("Radial gradient <b>radius</b>"),
  79     N_("Radial gradient <b>radius</b>"),
  80     N_("Radial gradient <b>focus</b>"), // POINT_RG_FOCUS
  81     N_("Radial gradient <b>mid stop</b>"),
  82     N_("Radial gradient <b>mid stop</b>")
  83 };
  84
  85 static void
  86 gr_drag_sel_changed(Inkscape::Selection */*selection*/, gpointer data)
  87 {
  88     GrDrag *drag = (GrDrag *) data;
  89     drag->updateDraggers ();
  90     drag->updateLines ();
  91     drag->updateLevels ();
  92 }
  93
  94 static void
  95 gr_drag_sel_modified (Inkscape::Selection */*selection*/, guint /*flags*/, gpointer data)
  96 {
  97     GrDrag *drag = (GrDrag *) data;
  98     if (drag->local_change) {
  99         drag->local_change = false;
 100     } else {
 101         drag->updateDraggers ();
 102     }
 103     drag->updateLines ();
 104     drag->updateLevels ();
 105 }
 106
 107 /**
 108 When a _query_style_signal is received, check that \a property requests fill/stroke/opacity (otherwise
 109 skip), and fill the \a style with the averaged color of all draggables of the selected dragger, if
 110 any.
 111 */
 112 int
 113 gr_drag_style_query (SPStyle *style, int property, gpointer data)
 114 {
 115     GrDrag *drag = (GrDrag *) data;
 116
 117     if (property != QUERY_STYLE_PROPERTY_FILL && property != QUERY_STYLE_PROPERTY_STROKE && property != QUERY_STYLE_PROPERTY_MASTEROPACITY) {
 118         return QUERY_STYLE_NOTHING;
 119     }
 120
 121     if (!drag->selected) {
 122         return QUERY_STYLE_NOTHING;
 123     } else {
 124         int ret = QUERY_STYLE_NOTHING;
 125
 126         float cf[4];
 127         cf[0] = cf[1] = cf[2] = cf[3] = 0;
 128
 129         int count = 0;
 130
 131         for (GList *i = drag->selected; i != NULL; i = i->next) { // for all selected draggers
 132             GrDragger *d = (GrDragger *) i->data;
 133             for (GSList const* j = d->draggables; j != NULL; j = j->next) { // for all draggables of dragger
 134                 GrDraggable *draggable = (GrDraggable *) j->data;
 135
 136                 if (ret == QUERY_STYLE_NOTHING) {
 137                     ret = QUERY_STYLE_SINGLE;
 138                 } else if (ret == QUERY_STYLE_SINGLE) {
 139                     ret = QUERY_STYLE_MULTIPLE_AVERAGED;
 140                 }
 141
 142                 guint32 c = sp_item_gradient_stop_query_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 143                 cf[0] += SP_RGBA32_R_F (c);
 144                 cf[1] += SP_RGBA32_G_F (c);
 145                 cf[2] += SP_RGBA32_B_F (c);
 146                 cf[3] += SP_RGBA32_A_F (c);
 147
 148                 count ++;
 149             }
 150         }
 151
 152         if (count) {
 153             cf[0] /= count;
 154             cf[1] /= count;
 155             cf[2] /= count;
 156             cf[3] /= count;
 157
 158             // set both fill and stroke with our stop-color and stop-opacity
 159             style->fill.clear();
 160             style->fill.setColor( cf[0], cf[1], cf[2] );
 161             style->fill.set = TRUE;
 162             style->stroke.clear();
 163             style->stroke.setColor( cf[0], cf[1], cf[2] );
 164             style->stroke.set = TRUE;
 165
 166             style->fill_opacity.value = SP_SCALE24_FROM_FLOAT (1.0);
 167             style->fill_opacity.set = TRUE;
 168             style->stroke_opacity.value = SP_SCALE24_FROM_FLOAT (1.0);
 169             style->stroke_opacity.set = TRUE;
 170
 171             style->opacity.value = SP_SCALE24_FROM_FLOAT (cf[3]);
 172             style->opacity.set = TRUE;
 173         }
 174
 175         return ret;
 176     }
 177 }
 178
 179 Glib::ustring GrDrag::makeStopSafeColor( gchar const *str, bool &isNull )
 180 {
 181     Glib::ustring colorStr;
 182     if ( str ) {
 183         isNull = false;
 184         colorStr = str;
 185         Glib::ustring::size_type pos = colorStr.find("url(#");
 186         if ( pos != Glib::ustring::npos ) {
 187             Glib::ustring targetName = colorStr.substr(pos + 5, colorStr.length() - 6);
 188             const GSList *gradients = sp_document_get_resource_list(desktop->doc(), "gradient");
 189             for (const GSList *item = gradients; item; item = item->next) {
 190                 SPGradient* grad = SP_GRADIENT(item->data);
 191                 if ( targetName == grad->getId() ) {
 192                     SPGradient *vect = grad->getVector();
 193                     SPStop *firstStop = (vect) ? vect->getFirstStop() : grad->getFirstStop();
 194                     if (firstStop) {
 195                         Glib::ustring stopColorStr;
 196                         if (firstStop->currentColor) {
 197                             stopColorStr = sp_object_get_style_property(firstStop, "color", NULL);
 198                         } else {
 199                             stopColorStr = firstStop->specified_color.toString();
 200                         }
 201                         if ( !stopColorStr.empty() ) {
 202                             colorStr = stopColorStr;
 203                         }
 204                     }
 205                     break;
 206                 }
 207             }
 208         }
 209     } else {
 210         isNull = true;
 211     }
 212
 213     return colorStr;
 214 }
 215
 216 bool GrDrag::styleSet( const SPCSSAttr *css )
 217 {
 218     if (!selected) {
 219         return false;
 220     }
 221
 222     SPCSSAttr *stop = sp_repr_css_attr_new();
 223
 224     // See if the css contains interesting properties, and if so, translate them into the format
 225     // acceptable for gradient stops
 226
 227     // any of color properties, in order of increasing priority:
 228     if (css->attribute("flood-color")) {
 229         sp_repr_css_set_property (stop, "stop-color", css->attribute("flood-color"));
 230     }
 231
 232     if (css->attribute("lighting-color")) {
 233         sp_repr_css_set_property (stop, "stop-color", css->attribute("lighting-color"));
 234     }
 235
 236     if (css->attribute("color")) {
 237         sp_repr_css_set_property (stop, "stop-color", css->attribute("color"));
 238     }
 239
 240     if (css->attribute("stroke") && strcmp(css->attribute("stroke"), "none")) {
 241         sp_repr_css_set_property (stop, "stop-color", css->attribute("stroke"));
 242     }
 243
 244     if (css->attribute("fill") && strcmp(css->attribute("fill"), "none")) {
 245         sp_repr_css_set_property (stop, "stop-color", css->attribute("fill"));
 246     }
 247
 248     if (css->attribute("stop-color")) {
 249         sp_repr_css_set_property (stop, "stop-color", css->attribute("stop-color"));
 250     }
 251
 252     // Make sure the style is allowed for gradient stops.
 253     if ( !sp_repr_css_property_is_unset( stop, "stop-color") ) {
 254         bool stopIsNull = false;
 255         Glib::ustring tmp = makeStopSafeColor( sp_repr_css_property( stop, "stop-color", "" ), stopIsNull );
 256         if ( !stopIsNull && !tmp.empty() ) {
 257             sp_repr_css_set_property( stop, "stop-color", tmp.c_str() );
 258         }
 259     }
 260
 261
 262     if (css->attribute("stop-opacity")) { // direct setting of stop-opacity has priority
 263         sp_repr_css_set_property(stop, "stop-opacity", css->attribute("stop-opacity"));
 264     } else {  // multiply all opacity properties:
 265         gdouble accumulated = 1.0;
 266         accumulated *= sp_svg_read_percentage(css->attribute("flood-opacity"), 1.0);
 267         accumulated *= sp_svg_read_percentage(css->attribute("opacity"), 1.0);
 268         accumulated *= sp_svg_read_percentage(css->attribute("stroke-opacity"), 1.0);
 269         accumulated *= sp_svg_read_percentage(css->attribute("fill-opacity"), 1.0);
 270
 271         Inkscape::CSSOStringStream os;
 272         os << accumulated;
 273         sp_repr_css_set_property(stop, "stop-opacity", os.str().c_str());
 274
 275         if ((css->attribute("fill") && !css->attribute("stroke") && !strcmp(css->attribute("fill"), "none")) ||
 276             (css->attribute("stroke") && !css->attribute("fill") && !strcmp(css->attribute("stroke"), "none"))) {
 277             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
 278         }
 279     }
 280
 281     if (!stop->attributeList()) { // nothing for us here, pass it on
 282         sp_repr_css_attr_unref(stop);
 283         return false;
 284     }
 285
 286     for (GList const* sel = selected; sel != NULL; sel = sel->next) { // for all selected draggers
 287         GrDragger* dragger = reinterpret_cast<GrDragger*>(sel->data);
 288         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 289             GrDraggable *draggable = reinterpret_cast<GrDraggable *>(i->data);
 290
 291             local_change = true;
 292             sp_item_gradient_stop_set_style(draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke, stop);
 293         }
 294     }
 295
 296     //sp_repr_css_print(stop);
 297     sp_repr_css_attr_unref(stop);
 298     return true;
 299 }
 300
 301 guint32 GrDrag::getColor()
 302 {
 303     if (!selected) return 0;
 304
 305     float cf[4];
 306     cf[0] = cf[1] = cf[2] = cf[3] = 0;
 307
 308     int count = 0;
 309
 310     for (GList *i = selected; i != NULL; i = i->next) { // for all selected draggers
 311         GrDragger *d = (GrDragger *) i->data;
 312         for (GSList const* j = d->draggables; j != NULL; j = j->next) { // for all draggables of dragger
 313             GrDraggable *draggable = (GrDraggable *) j->data;
 314
 315             guint32 c = sp_item_gradient_stop_query_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 316             cf[0] += SP_RGBA32_R_F (c);
 317             cf[1] += SP_RGBA32_G_F (c);
 318             cf[2] += SP_RGBA32_B_F (c);
 319             cf[3] += SP_RGBA32_A_F (c);
 320
 321             count ++;
 322         }
 323     }
 324
 325     if (count) {
 326         cf[0] /= count;
 327         cf[1] /= count;
 328         cf[2] /= count;
 329         cf[3] /= count;
 330     }
 331
 332     return SP_RGBA32_F_COMPOSE(cf[0], cf[1], cf[2], cf[3]);
 333 }
 334
 335 SPStop *
 336 GrDrag::addStopNearPoint (SPItem *item, Geom::Point mouse_p, double tolerance)
 337 {
 338     gfloat offset; // type of SPStop.offset = gfloat
 339     SPGradient *gradient;
 340     bool fill_or_stroke = true;
 341     bool r1_knot = false;
 342
 343     bool addknot = false;
 344     do {
 345         gradient = sp_item_gradient (item, fill_or_stroke);
 346         if (SP_IS_LINEARGRADIENT(gradient)) {
 347             Geom::Point begin   = sp_item_gradient_get_coords(item, POINT_LG_BEGIN, 0, fill_or_stroke);
 348             Geom::Point end     = sp_item_gradient_get_coords(item, POINT_LG_END, 0, fill_or_stroke);
 349
 350             Geom::Point nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 351             double dist_screen = Geom::L2 (mouse_p - nearest);
 352             if ( dist_screen < tolerance ) {
 353                 // add the knot
 354                 offset = get_offset_between_points(nearest, begin, end);
 355                 addknot = true;
 356                 break; // break out of the while loop: add only one knot
 357             }
 358         } else if (SP_IS_RADIALGRADIENT(gradient)) {
 359             Geom::Point begin = sp_item_gradient_get_coords(item, POINT_RG_CENTER, 0, fill_or_stroke);
 360             Geom::Point end   = sp_item_gradient_get_coords(item, POINT_RG_R1, 0, fill_or_stroke);
 361             Geom::Point nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 362             double dist_screen = Geom::L2 (mouse_p - nearest);
 363             if ( dist_screen < tolerance ) {
 364                 offset = get_offset_between_points(nearest, begin, end);
 365                 addknot = true;
 366                 r1_knot = true;
 367                 break; // break out of the while loop: add only one knot
 368             }
 369
 370             end    = sp_item_gradient_get_coords(item, POINT_RG_R2, 0, fill_or_stroke);
 371             nearest = snap_vector_midpoint (mouse_p, begin, end, 0);
 372             dist_screen = Geom::L2 (mouse_p - nearest);
 373             if ( dist_screen < tolerance ) {
 374                 offset = get_offset_between_points(nearest, begin, end);
 375                 addknot = true;
 376                 r1_knot = false;
 377                 break; // break out of the while loop: add only one knot
 378             }
 379         }
 380         fill_or_stroke = !fill_or_stroke;
 381     } while (!fill_or_stroke && !addknot) ;
 382
 383     if (addknot) {
 384         SPGradient *vector = sp_gradient_get_forked_vector_if_necessary (gradient, false);
 385         SPStop* prev_stop = vector->getFirstStop();
 386         SPStop* next_stop = prev_stop->getNextStop();
 387         guint i = 1;
 388         while ( (next_stop) && (next_stop->offset < offset) ) {
 389             prev_stop = next_stop;
 390             next_stop = next_stop->getNextStop();
 391             i++;
 392         }
 393         if (!next_stop) {
 394             // logical error: the endstop should have offset 1 and should always be more than this offset here
 395             return NULL;
 396         }
 397
 398
 399         SPStop *newstop = sp_vector_add_stop (vector, prev_stop, next_stop, offset);
 400         gradient->ensureVector();
 401         updateDraggers();
 402
 403         return newstop;
 404     }
 405
 406     return NULL;
 407 }
 408
 409
 410 bool
 411 GrDrag::dropColor(SPItem */*item*/, gchar const *c, Geom::Point p)
 412 {
 413     // Note: not sure if a null pointer can come in for the style, but handle that just in case
 414     bool stopIsNull = false;
 415     Glib::ustring toUse = makeStopSafeColor( c, stopIsNull );
 416
 417     // first, see if we can drop onto one of the existing draggers
 418     for (GList *i = draggers; i != NULL; i = i->next) { // for all draggables of dragger
 419         GrDragger *d = (GrDragger *) i->data;
 420
 421         if (Geom::L2(p - d->point)*desktop->current_zoom() < 5) {
 422            SPCSSAttr *stop = sp_repr_css_attr_new ();
 423            sp_repr_css_set_property( stop, "stop-color", stopIsNull ? 0 : toUse.c_str() );
 424            sp_repr_css_set_property( stop, "stop-opacity", "1" );
 425            for (GSList *j = d->draggables; j != NULL; j = j->next) { // for all draggables of dragger
 426                GrDraggable *draggable = (GrDraggable *) j->data;
 427                local_change = true;
 428                sp_item_gradient_stop_set_style (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke, stop);
 429            }
 430            sp_repr_css_attr_unref(stop);
 431            return true;
 432         }
 433     }
 434
 435     // now see if we're over line and create a new stop
 436     bool over_line = false;
 437     SPCtrlLine *line = NULL;
 438     if (lines) {
 439         for (GSList *l = lines; (l != NULL) && (!over_line); l = l->next) {
 440             line = (SPCtrlLine*) l->data;
 441             Geom::Point nearest = snap_vector_midpoint (p, line->s, line->e, 0);
 442             double dist_screen = Geom::L2 (p - nearest) * desktop->current_zoom();
 443             if (line->item && dist_screen < 5) {
 444                 SPStop *stop = addStopNearPoint (line->item, p, 5/desktop->current_zoom());
 445                 if (stop) {
 446                     SPCSSAttr *css = sp_repr_css_attr_new ();
 447                     sp_repr_css_set_property( css, "stop-color", stopIsNull ? 0 : toUse.c_str() );
 448                     sp_repr_css_set_property( css, "stop-opacity", "1" );
 449                     sp_repr_css_change (SP_OBJECT_REPR (stop), css, "style");
 450                     return true;
 451                 }
 452             }
 453         }
 454     }
 455
 456     return false;
 457 }
 458
 459
 460 GrDrag::GrDrag(SPDesktop *desktop) :
 461     selected(0),
 462     keep_selection(false),
 463     local_change(false),
 464     desktop(desktop),
 465     hor_levels(),
 466     vert_levels(),
 467     draggers(0),
 468     lines(0),
 469     selection(sp_desktop_selection(desktop)),
 470     sel_changed_connection(),
 471     sel_modified_connection(),
 472     style_set_connection(),
 473     style_query_connection()
 474 {
 475     sel_changed_connection = selection->connectChanged(
 476         sigc::bind(
 477             sigc::ptr_fun(&gr_drag_sel_changed),
 478             (gpointer)this )
 479
 480         );
 481     sel_modified_connection = selection->connectModified(
 482         sigc::bind(
 483             sigc::ptr_fun(&gr_drag_sel_modified),
 484             (gpointer)this )
 485         );
 486
 487     style_set_connection = desktop->connectSetStyle( sigc::mem_fun(*this, &GrDrag::styleSet) );
 488
 489     style_query_connection = desktop->connectQueryStyle(
 490         sigc::bind(
 491             sigc::ptr_fun(&gr_drag_style_query),
 492             (gpointer)this )
 493         );
 494
 495     updateDraggers();
 496     updateLines();
 497     updateLevels();
 498
 499     if (desktop->gr_item) {
 500         setSelected(getDraggerFor(desktop->gr_item, desktop->gr_point_type, desktop->gr_point_i, desktop->gr_fill_or_stroke));
 501     }
 502 }
 503
 504 GrDrag::~GrDrag()
 505 {
 506     this->sel_changed_connection.disconnect();
 507     this->sel_modified_connection.disconnect();
 508     this->style_set_connection.disconnect();
 509     this->style_query_connection.disconnect();
 510
 511     if (this->selected) {
 512         GrDraggable *draggable = (GrDraggable *)   ((GrDragger*)this->selected->data)->draggables->data;
 513         desktop->gr_item = draggable->item;
 514         desktop->gr_point_type = draggable->point_type;
 515         desktop->gr_point_i = draggable->point_i;
 516         desktop->gr_fill_or_stroke = draggable->fill_or_stroke;
 517     } else {
 518         desktop->gr_item = NULL;
 519         desktop->gr_point_type = 0;
 520         desktop->gr_point_i = 0;
 521         desktop->gr_fill_or_stroke = true;
 522     }
 523
 524     deselect_all();
 525     for (GList *l = this->draggers; l != NULL; l = l->next) {
 526         delete ((GrDragger *) l->data);
 527     }
 528     g_list_free (this->draggers);
 529     this->draggers = NULL;
 530     this->selected = NULL;
 531
 532     for (GSList *l = this->lines; l != NULL; l = l->next) {
 533         gtk_object_destroy( GTK_OBJECT (l->data));
 534     }
 535     g_slist_free (this->lines);
 536     this->lines = NULL;
 537 }
 538
 539 GrDraggable::GrDraggable (SPItem *item, guint point_type, guint point_i, bool fill_or_stroke)
 540 {
 541     this->item = item;
 542     this->point_type = point_type;
 543     this->point_i = point_i;
 544     this->fill_or_stroke = fill_or_stroke;
 545
 546     g_object_ref (G_OBJECT (this->item));
 547 }
 548
 549 GrDraggable::~GrDraggable ()
 550 {
 551     g_object_unref (G_OBJECT (this->item));
 552 }
 553
 554
 555 SPObject *GrDraggable::getServer()
 556 {
 557     if (!item) {
 558         return NULL;
 559     }
 560
 561     SPObject *server = NULL;
 562     if (fill_or_stroke) {
 563         server = item->style->getFillPaintServer();
 564     }else {
 565         server = item->style->getStrokePaintServer();
 566     }
 567
 568     return server;
 569 }
 570
 571 static void
 572 gr_knot_moved_handler(SPKnot *knot, Geom::Point const &ppointer, guint state, gpointer data)
 573 {
 574     GrDragger *dragger = (GrDragger *) data;
 575     GrDrag *drag = dragger->parent;
 576
 577     Geom::Point p = ppointer;
 578
 579     SPDesktop *desktop = dragger->parent->desktop;
 580     SnapManager &m = desktop->namedview->snap_manager;
 581     double snap_dist = m.snapprefs.getObjectTolerance() / dragger->parent->desktop->current_zoom();
 582
 583     if (state & GDK_SHIFT_MASK) {
 584         // with Shift; unsnap if we carry more than one draggable
 585         if (dragger->draggables && dragger->draggables->next) {
 586             // create a new dragger
 587             GrDragger *dr_new = new GrDragger (dragger->parent, dragger->point, NULL);
 588             dragger->parent->draggers = g_list_prepend (dragger->parent->draggers, dr_new);
 589             // relink to it all but the first draggable in the list
 590             for (GSList const* i = dragger->draggables->next; i != NULL; i = i->next) {
 591                 GrDraggable *draggable = (GrDraggable *) i->data;
 592                 dr_new->addDraggable (draggable);
 593             }
 594             dr_new->updateKnotShape();
 595             g_slist_free (dragger->draggables->next);
 596             dragger->draggables->next = NULL;
 597             dragger->updateKnotShape();
 598             dragger->updateTip();
 599         }
 600     } else if (!(state & GDK_CONTROL_MASK)) {
 601         // without Shift or Ctrl; see if we need to snap to another dragger
 602         for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 603             GrDragger *d_new = (GrDragger *) di->data;
 604             if (dragger->mayMerge(d_new) && Geom::L2 (d_new->point - p) < snap_dist) {
 605
 606                 // Merge draggers:
 607                 for (GSList const* i = dragger->draggables; i != NULL; i = i->next) { // for all draggables of dragger
 608                     GrDraggable *draggable = (GrDraggable *) i->data;
 609                     // copy draggable to d_new:
 610                     GrDraggable *da_new = new GrDraggable (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
 611                     d_new->addDraggable (da_new);
 612                 }
 613
 614                 // unlink and delete this dragger
 615                 dragger->parent->draggers = g_list_remove (dragger->parent->draggers, dragger);
 616                 delete dragger;
 617
 618                 // update the new merged dragger
 619                 d_new->fireDraggables(true, false, true);
 620                 d_new->parent->updateLines();
 621                 d_new->parent->setSelected (d_new);
 622                 d_new->updateKnotShape ();
 623                 d_new->updateTip ();
 624                 d_new->updateDependencies(true);
 625                 sp_document_done (sp_desktop_document (d_new->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 626                                   _("Merge gradient handles"));
 627                 return;
 628             }
 629         }
 630     }
 631
 632     if (!((state & GDK_SHIFT_MASK) || (state & GDK_CONTROL_MASK))) {
 633         m.setup(desktop);
 634         Inkscape::SnappedPoint s = m.freeSnap(Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_OTHER_HANDLE));
 635         m.unSetup();
 636         if (s.getSnapped()) {
 637             p = s.getPoint();
 638             sp_knot_moveto (knot, p);
 639         }
 640     } else if (state & GDK_CONTROL_MASK) {
 641         SnappedConstraints sc;
 642         Inkscape::SnapCandidatePoint scp = Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_OTHER_HANDLE);
 643         Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 644         unsigned snaps = abs(prefs->getInt("/options/rotationsnapsperpi/value", 12));
 645         /* 0 means no snapping. */
 646
 647         for (GSList const* i = dragger->draggables; i != NULL; i = i->next) {
 648             GrDraggable *draggable = (GrDraggable *) i->data;
 649
 650             Geom::Point dr_snap(Geom::infinity(), Geom::infinity());
 651
 652             if (draggable->point_type == POINT_LG_BEGIN || draggable->point_type == POINT_LG_END) {
 653                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 654                     GrDragger *d_new = (GrDragger *) di->data;
 655                     if (d_new == dragger)
 656                         continue;
 657                     if (d_new->isA (draggable->item,
 658                                     draggable->point_type == POINT_LG_BEGIN? POINT_LG_END : POINT_LG_BEGIN,
 659                                     draggable->fill_or_stroke)) {
 660                         // found the other end of the linear gradient;
 661                         if (state & GDK_SHIFT_MASK) {
 662                             // moving linear around center
 663                             Geom::Point center = Geom::Point (0.5*(d_new->point + dragger->point));
 664                             dr_snap = center;
 665                         } else {
 666                             // moving linear around the other end
 667                             dr_snap = d_new->point;
 668                         }
 669                     }
 670                 }
 671             } else if (draggable->point_type == POINT_RG_R1 || draggable->point_type == POINT_RG_R2 || draggable->point_type == POINT_RG_FOCUS) {
 672                 for (GList *di = dragger->parent->draggers; di != NULL; di = di->next) {
 673                     GrDragger *d_new = (GrDragger *) di->data;
 674                     if (d_new == dragger)
 675                         continue;
 676                     if (d_new->isA (draggable->item,
 677                                     POINT_RG_CENTER,
 678                                     draggable->fill_or_stroke)) {
 679                         // found the center of the radial gradient;
 680                         dr_snap = d_new->point;
 681                     }
 682                 }
 683             } else if (draggable->point_type == POINT_RG_CENTER) {
 684                 // radial center snaps to hor/vert relative to its original position
 685                 dr_snap = dragger->point_original;
 686             }
 687
 688             // dr_snap contains the origin of the gradient, whereas p will be the new endpoint which we will try to snap now
 689             Inkscape::SnappedPoint sp;
 690             if (dr_snap.isFinite()) {
 691                 m.setup(desktop);
 692                 if (state & GDK_MOD1_MASK) {
 693                     // with Alt, snap to the original angle and its perpendiculars
 694                     sp = m.constrainedAngularSnap(scp, dragger->point_original, dr_snap, 2);
 695                 } else {
 696                     // with Ctrl, snap to M_PI/snaps
 697                     sp = m.constrainedAngularSnap(scp, boost::optional<Geom::Point>(), dr_snap, snaps);
 698                 }
 699                 m.unSetup();
 700                 sc.points.push_back(sp);
 701             }
 702         }
 703
 704         m.setup(desktop, false); // turn of the snap indicator temporarily
 705         Inkscape::SnappedPoint bsp = m.findBestSnap(scp, sc, true);
 706         m.unSetup();
 707         if (!bsp.getSnapped()) {
 708             // If we didn't truly snap to an object or to a grid, then we will still have to look for the
 709             // closest projection onto one of the constraints. findBestSnap() will not do this for us
 710             for (std::list<Inkscape::SnappedPoint>::const_iterator i = sc.points.begin(); i != sc.points.end(); i++) {
 711                 if (i == sc.points.begin() || (Geom::L2((*i).getPoint() - p) < Geom::L2(bsp.getPoint() - p))) {
 712                     bsp.setPoint((*i).getPoint());
 713                     bsp.setTarget(Inkscape::SNAPTARGET_CONSTRAINED_ANGLE);
 714                 }
 715             }
 716         }
 717         //p = sc.points.front().getPoint();
 718         p = bsp.getPoint();
 719         sp_knot_moveto (knot, p);
 720     }
 721
 722     drag->keep_selection = (bool) g_list_find(drag->selected, dragger);
 723     bool scale_radial = (state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK);
 724
 725     if (drag->keep_selection) {
 726         Geom::Point diff = p - dragger->point;
 727         drag->selected_move_nowrite (diff[Geom::X], diff[Geom::Y], scale_radial);
 728     } else {
 729         dragger->point = p;
 730         dragger->fireDraggables (false, scale_radial);
 731         dragger->updateDependencies(false);
 732     }
 733
 734 }
 735
 736
 737 static void
 738 gr_midpoint_limits(GrDragger *dragger, SPObject *server, Geom::Point *begin, Geom::Point *end, Geom::Point *low_lim, Geom::Point *high_lim, GSList **moving)
 739 {
 740
 741     GrDrag *drag = dragger->parent;
 742     // a midpoint dragger can (logically) only contain one GrDraggable
 743     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 744
 745     // get begin and end points between which dragging is allowed:
 746     // the draglimits are between knot(lowest_i - 1) and knot(highest_i + 1)
 747     *moving = g_slist_append(*moving, dragger);
 748
 749     guint lowest_i = draggable->point_i;
 750     guint highest_i = draggable->point_i;
 751     GrDragger *lowest_dragger = dragger;
 752     GrDragger *highest_dragger = dragger;
 753     if (dragger->isSelected()) {
 754         GrDragger* d_add;
 755         while ( true )
 756         {
 757             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 758             if ( d_add && g_list_find(drag->selected, d_add) ) {
 759                 lowest_i = lowest_i - 1;
 760                 *moving = g_slist_prepend(*moving, d_add);
 761                 lowest_dragger = d_add;
 762             } else {
 763                 break;
 764             }
 765         }
 766
 767         while ( true )
 768         {
 769             d_add = drag->getDraggerFor(draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 770             if ( d_add && g_list_find(drag->selected, d_add) ) {
 771                 highest_i = highest_i + 1;
 772                 *moving = g_slist_append(*moving, d_add);
 773                 highest_dragger = d_add;
 774             } else {
 775                 break;
 776             }
 777         }
 778     }
 779
 780     if ( SP_IS_LINEARGRADIENT(server) ) {
 781         guint num = SP_LINEARGRADIENT(server)->vector.stops.size();
 782         GrDragger *d_temp;
 783         if (lowest_i == 1) {
 784             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke);
 785         } else {
 786             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, lowest_i - 1, draggable->fill_or_stroke);
 787         }
 788         if (d_temp)
 789             *begin = d_temp->point;
 790
 791         d_temp = drag->getDraggerFor (draggable->item, POINT_LG_MID, highest_i + 1, draggable->fill_or_stroke);
 792         if (d_temp == NULL) {
 793             d_temp = drag->getDraggerFor (draggable->item, POINT_LG_END, num-1, draggable->fill_or_stroke);
 794         }
 795         if (d_temp)
 796             *end = d_temp->point;
 797     } else if ( SP_IS_RADIALGRADIENT(server) ) {
 798         guint num = SP_RADIALGRADIENT(server)->vector.stops.size();
 799         GrDragger *d_temp;
 800         if (lowest_i == 1) {
 801             d_temp = drag->getDraggerFor (draggable->item, POINT_RG_CENTER, 0, draggable->fill_or_stroke);
 802         } else {
 803             d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, lowest_i - 1, draggable->fill_or_stroke);
 804         }
 805         if (d_temp)
 806             *begin = d_temp->point;
 807
 808         d_temp = drag->getDraggerFor (draggable->item, draggable->point_type, highest_i + 1, draggable->fill_or_stroke);
 809         if (d_temp == NULL) {
 810             d_temp = drag->getDraggerFor (draggable->item, (draggable->point_type==POINT_RG_MID1) ? POINT_RG_R1 : POINT_RG_R2, num-1, draggable->fill_or_stroke);
 811         }
 812         if (d_temp)
 813             *end = d_temp->point;
 814     }
 815
 816     *low_lim  = dragger->point - (lowest_dragger->point - *begin);
 817     *high_lim = dragger->point - (highest_dragger->point - *end);
 818 }
 819
 820
 821
 822 /**
 823 Called when a midpoint knot is dragged.
 824 */
 825 static void
 826 gr_knot_moved_midpoint_handler(SPKnot */*knot*/, Geom::Point const &ppointer, guint state, gpointer data)
 827 {
 828     GrDragger *dragger = (GrDragger *) data;
 829     GrDrag *drag = dragger->parent;
 830     // a midpoint dragger can (logically) only contain one GrDraggable
 831     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 832
 833     // FIXME: take from prefs
 834     double snap_fraction = 0.1;
 835
 836     Geom::Point p = ppointer;
 837     Geom::Point begin(0,0), end(0,0);
 838     Geom::Point low_lim(0,0), high_lim(0,0);
 839
 840     SPObject *server = draggable->getServer();
 841
 842     GSList *moving = NULL;
 843     gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
 844
 845     if (state & GDK_CONTROL_MASK) {
 846         p = snap_vector_midpoint (p, low_lim, high_lim, snap_fraction);
 847     } else {
 848         p = snap_vector_midpoint (p, low_lim, high_lim, 0);
 849         if (!(state & GDK_SHIFT_MASK)) {
 850             Inkscape::Snapper::SnapConstraint cl(low_lim, high_lim - low_lim);
 851             SPDesktop *desktop = dragger->parent->desktop;
 852             SnapManager &m = desktop->namedview->snap_manager;
 853             m.setup(desktop);
 854             m.constrainedSnapReturnByRef(p, Inkscape::SNAPSOURCE_OTHER_HANDLE, cl);
 855             m.unSetup();
 856         }
 857     }
 858     Geom::Point displacement = p - dragger->point;
 859
 860     for (GSList const* i = moving; i != NULL; i = i->next) {
 861         GrDragger *drg = (GrDragger*) i->data;
 862         SPKnot *drgknot = drg->knot;
 863         Geom::Point this_move = displacement;
 864         if (state & GDK_MOD1_MASK) {
 865             // FIXME: unify all these profiles (here, in nodepath, in tweak) in one place
 866             double alpha = 1.0;
 867             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
 868                 double x = Geom::L2(drg->point - dragger->point)/Geom::L2(end - dragger->point);
 869                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 870             } else { // drg is on the begin side from dragger
 871                 double x = Geom::L2(drg->point - dragger->point)/Geom::L2(begin - dragger->point);
 872                 this_move = (0.5 * cos (M_PI * (pow(x, alpha))) + 0.5) * this_move;
 873             }
 874         }
 875         drg->point += this_move;
 876         sp_knot_moveto (drgknot, drg->point);
 877         drg->fireDraggables (false);
 878         drg->updateDependencies(false);
 879     }
 880
 881     g_slist_free(moving);
 882
 883     drag->keep_selection = dragger->isSelected();
 884 }
 885
 886
 887
 888 static void
 889 gr_knot_grabbed_handler (SPKnot */*knot*/, unsigned int /*state*/, gpointer data)
 890 {
 891     GrDragger *dragger = (GrDragger *) data;
 892
 893     sp_canvas_force_full_redraw_after_interruptions(dragger->parent->desktop->canvas, 5);
 894 }
 895
 896 /**
 897 Called when the mouse releases a dragger knot; changes gradient writing to repr, updates other draggers if needed
 898 */
 899 static void
 900 gr_knot_ungrabbed_handler (SPKnot *knot, unsigned int state, gpointer data)
 901 {
 902     GrDragger *dragger = (GrDragger *) data;
 903
 904     sp_canvas_end_forced_full_redraws(dragger->parent->desktop->canvas);
 905
 906     dragger->point_original = dragger->point = knot->pos;
 907
 908     if ((state & GDK_CONTROL_MASK) && (state & GDK_SHIFT_MASK)) {
 909         dragger->fireDraggables (true, true);
 910     } else {
 911         dragger->fireDraggables (true);
 912     }
 913
 914     for (GList *i = dragger->parent->selected; i != NULL; i = i->next) {
 915         GrDragger *d = (GrDragger *) i->data;
 916         if (d == dragger)
 917             continue;
 918         d->fireDraggables (true);
 919     }
 920
 921     // make this dragger selected
 922     if (!dragger->parent->keep_selection) {
 923         dragger->parent->setSelected (dragger);
 924     }
 925     dragger->parent->keep_selection = false;
 926
 927     dragger->updateDependencies(true);
 928
 929     // we did an undoable action
 930     sp_document_done (sp_desktop_document (dragger->parent->desktop), SP_VERB_CONTEXT_GRADIENT,
 931                       _("Move gradient handle"));
 932 }
 933
 934 /**
 935 Called when a dragger knot is clicked; selects the dragger or deletes it depending on the
 936 state of the keyboard keys
 937 */
 938 static void
 939 gr_knot_clicked_handler(SPKnot */*knot*/, guint state, gpointer data)
 940 {
 941     GrDragger *dragger = (GrDragger *) data;
 942     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
 943     if (!draggable) return;
 944
 945     if ( (state & GDK_CONTROL_MASK) && (state & GDK_MOD1_MASK ) ) {
 946     // delete this knot from vector
 947         SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
 948         gradient = gradient->getVector();
 949         if (gradient->vector.stops.size() > 2) { // 2 is the minimum
 950             SPStop *stop = NULL;
 951             switch (draggable->point_type) {  // if we delete first or last stop, move the next/previous to the edge
 952             case POINT_LG_BEGIN:
 953             case POINT_RG_CENTER:
 954                 stop = gradient->getFirstStop();
 955                 {
 956                     SPStop *next = stop->getNextStop();
 957                     if (next) {
 958                         next->offset = 0;
 959                         sp_repr_set_css_double (SP_OBJECT_REPR (next), "offset", 0);
 960                     }
 961                 }
 962                 break;
 963             case POINT_LG_END:
 964             case POINT_RG_R1:
 965             case POINT_RG_R2:
 966                 stop = sp_last_stop(gradient);
 967                 {
 968                     SPStop *prev = stop->getPrevStop();
 969                     if (prev) {
 970                         prev->offset = 1;
 971                         sp_repr_set_css_double (SP_OBJECT_REPR (prev), "offset", 1);
 972                     }
 973                 }
 974                 break;
 975             case POINT_LG_MID:
 976             case POINT_RG_MID1:
 977             case POINT_RG_MID2:
 978                 stop = sp_get_stop_i(gradient, draggable->point_i);
 979                 break;
 980             }
 981
 982             SP_OBJECT_REPR(gradient)->removeChild(SP_OBJECT_REPR(stop));
 983             sp_document_done (SP_OBJECT_DOCUMENT (gradient), SP_VERB_CONTEXT_GRADIENT,
 984                       _("Delete gradient stop"));
 985         }
 986     } else {
 987     // select the dragger
 988         dragger->point_original = dragger->point;
 989
 990         if ( state & GDK_SHIFT_MASK ) {
 991             dragger->parent->setSelected (dragger, true, false);
 992         } else {
 993             dragger->parent->setSelected (dragger);
 994         }
 995     }
 996 }
 997
 998 /**
 999 Called when a dragger knot is doubleclicked; opens gradient editor with the stop from the first draggable
1000 */
1001 static void
1002 gr_knot_doubleclicked_handler (SPKnot */*knot*/, guint /*state*/, gpointer data)
1003 {
1004     GrDragger *dragger = (GrDragger *) data;
1005
1006     dragger->point_original = dragger->point;
1007
1008     if (dragger->draggables == NULL)
1009         return;
1010
1011     GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
1012     sp_item_gradient_edit_stop (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
1013 }
1014
1015 /**
1016 Act upon all draggables of the dragger, setting them to the dragger's point
1017 */
1018 void
1019 GrDragger::fireDraggables (bool write_repr, bool scale_radial, bool merging_focus)
1020 {
1021     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1022         GrDraggable *draggable = (GrDraggable *) i->data;
1023
1024         // set local_change flag so that selection_changed callback does not regenerate draggers
1025         this->parent->local_change = true;
1026
1027         // change gradient, optionally writing to repr; prevent focus from moving if it's snapped
1028         // to the center, unless it's the first update upon merge when we must snap it to the point
1029         if (merging_focus ||
1030             !(draggable->point_type == POINT_RG_FOCUS && this->isA(draggable->item, POINT_RG_CENTER, draggable->point_i, draggable->fill_or_stroke)))
1031         {
1032             sp_item_gradient_set_coords (draggable->item, draggable->point_type, draggable->point_i, this->point, draggable->fill_or_stroke, write_repr, scale_radial);
1033         }
1034     }
1035 }
1036
1037 /**
1038 Checks if the dragger has a draggable with this point_type
1039  */
1040 bool
1041 GrDragger::isA (gint point_type)
1042 {
1043     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1044         GrDraggable *draggable = (GrDraggable *) i->data;
1045         if (draggable->point_type == point_type) {
1046             return true;
1047         }
1048     }
1049     return false;
1050 }
1051
1052 /**
1053 Checks if the dragger has a draggable with this item, point_type + point_i (number), fill_or_stroke
1054  */
1055 bool
1056 GrDragger::isA (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1057 {
1058     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1059         GrDraggable *draggable = (GrDraggable *) i->data;
1060         if ( (draggable->point_type == point_type) && (draggable->point_i == point_i) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
1061             return true;
1062         }
1063     }
1064     return false;
1065 }
1066
1067 /**
1068 Checks if the dragger has a draggable with this item, point_type, fill_or_stroke
1069  */
1070 bool
1071 GrDragger::isA (SPItem *item, gint point_type, bool fill_or_stroke)
1072 {
1073     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1074         GrDraggable *draggable = (GrDraggable *) i->data;
1075         if ( (draggable->point_type == point_type) && (draggable->item == item) && (draggable->fill_or_stroke == fill_or_stroke) ) {
1076             return true;
1077         }
1078     }
1079     return false;
1080 }
1081
1082 bool
1083 GrDraggable::mayMerge (GrDraggable *da2)
1084 {
1085     if ((this->item == da2->item) && (this->fill_or_stroke == da2->fill_or_stroke)) {
1086         // we must not merge the points of the same gradient!
1087         if (!((this->point_type == POINT_RG_FOCUS && da2->point_type == POINT_RG_CENTER) ||
1088               (this->point_type == POINT_RG_CENTER && da2->point_type == POINT_RG_FOCUS))) {
1089             // except that we can snap center and focus together
1090             return false;
1091         }
1092     }
1093     // disable merging of midpoints.
1094     if ( (this->point_type == POINT_LG_MID) || (da2->point_type == POINT_LG_MID)
1095          || (this->point_type == POINT_RG_MID1) || (da2->point_type == POINT_RG_MID1)
1096          || (this->point_type == POINT_RG_MID2) || (da2->point_type == POINT_RG_MID2) )
1097         return false;
1098
1099     return true;
1100 }
1101
1102 bool
1103 GrDragger::mayMerge (GrDragger *other)
1104 {
1105     if (this == other)
1106         return false;
1107
1108     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
1109         GrDraggable *da1 = (GrDraggable *) i->data;
1110         for (GSList const* j = other->draggables; j != NULL; j = j->next) { // for all draggables of other
1111             GrDraggable *da2 = (GrDraggable *) j->data;
1112             if (!da1->mayMerge(da2))
1113                 return false;
1114         }
1115     }
1116     return true;
1117 }
1118
1119 bool
1120 GrDragger::mayMerge (GrDraggable *da2)
1121 {
1122     for (GSList const* i = this->draggables; i != NULL; i = i->next) { // for all draggables of this
1123         GrDraggable *da1 = (GrDraggable *) i->data;
1124         if (!da1->mayMerge(da2))
1125             return false;
1126     }
1127     return true;
1128 }
1129
1130 /**
1131 Updates the statusbar tip of the dragger knot, based on its draggables
1132  */
1133 void
1134 GrDragger::updateTip ()
1135 {
1136     if (this->knot && this->knot->tip) {
1137         g_free (this->knot->tip);
1138         this->knot->tip = NULL;
1139     }
1140
1141     if (g_slist_length (this->draggables) == 1) {
1142         GrDraggable *draggable = (GrDraggable *) this->draggables->data;
1143         char *item_desc = sp_item_description(draggable->item);
1144         switch (draggable->point_type) {
1145             case POINT_LG_MID:
1146             case POINT_RG_MID1:
1147             case POINT_RG_MID2:
1148                 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"),
1149                                                    _(gr_knot_descr[draggable->point_type]),
1150                                                    draggable->point_i,
1151                                                    item_desc,
1152                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
1153                 break;
1154
1155             default:
1156                 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"),
1157                                                    _(gr_knot_descr[draggable->point_type]),
1158                                                    item_desc,
1159                                                    draggable->fill_or_stroke == false ? _(" (stroke)") : "");
1160                 break;
1161         }
1162         g_free(item_desc);
1163     } else if (g_slist_length (draggables) == 2 && isA (POINT_RG_CENTER) && isA (POINT_RG_FOCUS)) {
1164         this->knot->tip = g_strdup_printf (_("Radial gradient <b>center</b> and <b>focus</b>; drag with <b>Shift</b> to separate focus"));
1165     } else {
1166         int length = g_slist_length (this->draggables);
1167         this->knot->tip = g_strdup_printf (ngettext("Gradient point shared by <b>%d</b> gradient; drag with <b>Shift</b> to separate",
1168                                                     "Gradient point shared by <b>%d</b> gradients; drag with <b>Shift</b> to separate",
1169                                                     length),
1170                                            length);
1171     }
1172 }
1173
1174 /**
1175 Adds a draggable to the dragger
1176  */
1177 void
1178 GrDragger::updateKnotShape ()
1179 {
1180     if (!draggables)
1181         return;
1182     GrDraggable *last = (GrDraggable *) g_slist_last(draggables)->data;
1183     g_object_set (G_OBJECT (this->knot->item), "shape", gr_knot_shapes[last->point_type], NULL);
1184 }
1185
1186 /**
1187 Adds a draggable to the dragger
1188  */
1189 void
1190 GrDragger::addDraggable (GrDraggable *draggable)
1191 {
1192     this->draggables = g_slist_prepend (this->draggables, draggable);
1193
1194     this->updateTip();
1195 }
1196
1197
1198 /**
1199 Moves this dragger to the point of the given draggable, acting upon all other draggables
1200  */
1201 void
1202 GrDragger::moveThisToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1203 {
1204     GrDraggable *dr_first = (GrDraggable *) this->draggables->data;
1205     if (!dr_first) return;
1206
1207     this->point = sp_item_gradient_get_coords (dr_first->item, dr_first->point_type, dr_first->point_i, dr_first->fill_or_stroke);
1208     this->point_original = this->point;
1209
1210     sp_knot_moveto (this->knot, this->point);
1211
1212     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1213         GrDraggable *da = (GrDraggable *) i->data;
1214         if ( (da->item == item) &&
1215              (point_type == -1 || da->point_type == point_type) &&
1216              (point_i == -1 || da->point_i == point_i) &&
1217              (da->fill_or_stroke == fill_or_stroke) ) {
1218             continue;
1219         }
1220         sp_item_gradient_set_coords (da->item, da->point_type, da->point_i, this->point, da->fill_or_stroke, write_repr, false);
1221     }
1222     // FIXME: here we should also call this->updateDependencies(write_repr); to propagate updating, but how to prevent loops?
1223 }
1224
1225
1226 /**
1227 Moves all midstop draggables that depend on this one
1228  */
1229 void
1230 GrDragger::updateMidstopDependencies (GrDraggable *draggable, bool write_repr) {
1231     SPObject *server = draggable->getServer();
1232     if (!server)
1233         return;
1234     guint num = SP_GRADIENT(server)->vector.stops.size();
1235     if (num <= 2) return;
1236
1237     if ( SP_IS_LINEARGRADIENT(server) ) {
1238         for ( guint i = 1; i < num - 1; i++ ) {
1239             this->moveOtherToDraggable (draggable->item, POINT_LG_MID, i, draggable->fill_or_stroke, write_repr);
1240         }
1241     } else  if ( SP_IS_RADIALGRADIENT(server) ) {
1242         for ( guint i = 1; i < num - 1; i++ ) {
1243             this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, i, draggable->fill_or_stroke, write_repr);
1244             this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, i, draggable->fill_or_stroke, write_repr);
1245         }
1246     }
1247 }
1248
1249
1250 /**
1251 Moves all draggables that depend on this one
1252  */
1253 void
1254 GrDragger::updateDependencies (bool write_repr)
1255 {
1256     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1257         GrDraggable *draggable = (GrDraggable *) i->data;
1258         switch (draggable->point_type) {
1259             case POINT_LG_BEGIN:
1260                 {
1261                     // the end point is dependent only when dragging with ctrl+shift
1262                     this->moveOtherToDraggable (draggable->item, POINT_LG_END, -1, draggable->fill_or_stroke, write_repr);
1263
1264                     this->updateMidstopDependencies (draggable, write_repr);
1265                 }
1266                 break;
1267             case POINT_LG_END:
1268                 {
1269                     // the begin point is dependent only when dragging with ctrl+shift
1270                     this->moveOtherToDraggable (draggable->item, POINT_LG_BEGIN, 0, draggable->fill_or_stroke, write_repr);
1271
1272                     this->updateMidstopDependencies (draggable, write_repr);
1273                 }
1274                 break;
1275             case POINT_LG_MID:
1276                 // no other nodes depend on mid points.
1277                 break;
1278             case POINT_RG_R2:
1279                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1280                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1281                 this->updateMidstopDependencies (draggable, write_repr);
1282                 break;
1283             case POINT_RG_R1:
1284                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1285                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1286                 this->updateMidstopDependencies (draggable, write_repr);
1287                 break;
1288             case POINT_RG_CENTER:
1289                 this->moveOtherToDraggable (draggable->item, POINT_RG_R1, -1, draggable->fill_or_stroke, write_repr);
1290                 this->moveOtherToDraggable (draggable->item, POINT_RG_R2, -1, draggable->fill_or_stroke, write_repr);
1291                 this->moveOtherToDraggable (draggable->item, POINT_RG_FOCUS, -1, draggable->fill_or_stroke, write_repr);
1292                 this->updateMidstopDependencies (draggable, write_repr);
1293                 break;
1294             case POINT_RG_FOCUS:
1295                 // nothing can depend on that
1296                 break;
1297             case POINT_RG_MID1:
1298                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID2, draggable->point_i, draggable->fill_or_stroke, write_repr);
1299                 break;
1300             case POINT_RG_MID2:
1301                 this->moveOtherToDraggable (draggable->item, POINT_RG_MID1, draggable->point_i, draggable->fill_or_stroke, write_repr);
1302                 break;
1303             default:
1304                 break;
1305         }
1306     }
1307 }
1308
1309
1310
1311 GrDragger::GrDragger (GrDrag *parent, Geom::Point p, GrDraggable *draggable)
1312   : point(p),
1313     point_original(p)
1314 {
1315     this->draggables = NULL;
1316
1317     this->parent = parent;
1318
1319     // create the knot
1320     this->knot = sp_knot_new (parent->desktop, NULL);
1321     this->knot->setMode(SP_KNOT_MODE_XOR);
1322     this->knot->setFill(GR_KNOT_COLOR_NORMAL, GR_KNOT_COLOR_MOUSEOVER, GR_KNOT_COLOR_MOUSEOVER);
1323     this->knot->setStroke(0x0000007f, 0x0000007f, 0x0000007f);
1324     sp_knot_update_ctrl(this->knot);
1325
1326     // move knot to the given point
1327     sp_knot_set_position (this->knot, p, SP_KNOT_STATE_NORMAL);
1328     sp_knot_show (this->knot);
1329
1330     // connect knot's signals
1331     if ( (draggable)  // it can be NULL if a node in unsnapped (eg. focus point unsnapped from center)
1332                        // luckily, midstops never snap to other nodes so are never unsnapped...
1333          && ( (draggable->point_type == POINT_LG_MID)
1334               || (draggable->point_type == POINT_RG_MID1)
1335               || (draggable->point_type == POINT_RG_MID2) ) )
1336     {
1337         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_midpoint_handler), this);
1338     } else {
1339         this->handler_id = g_signal_connect (G_OBJECT (this->knot), "moved", G_CALLBACK (gr_knot_moved_handler), this);
1340     }
1341     g_signal_connect (G_OBJECT (this->knot), "clicked", G_CALLBACK (gr_knot_clicked_handler), this);
1342     g_signal_connect (G_OBJECT (this->knot), "doubleclicked", G_CALLBACK (gr_knot_doubleclicked_handler), this);
1343     g_signal_connect (G_OBJECT (this->knot), "grabbed", G_CALLBACK (gr_knot_grabbed_handler), this);
1344     g_signal_connect (G_OBJECT (this->knot), "ungrabbed", G_CALLBACK (gr_knot_ungrabbed_handler), this);
1345
1346     // add the initial draggable
1347     if (draggable)
1348         this->addDraggable (draggable);
1349     updateKnotShape();
1350 }
1351
1352 GrDragger::~GrDragger ()
1353 {
1354     // unselect if it was selected
1355     this->parent->setDeselected(this);
1356
1357     // disconnect signals
1358     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_moved_handler), this);
1359     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_clicked_handler), this);
1360     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_doubleclicked_handler), this);
1361     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_grabbed_handler), this);
1362     g_signal_handlers_disconnect_by_func(G_OBJECT(this->knot), (gpointer) G_CALLBACK (gr_knot_ungrabbed_handler), this);
1363
1364     /* unref should call destroy */
1365     g_object_unref (G_OBJECT (this->knot));
1366
1367     // delete all draggables
1368     for (GSList const* i = this->draggables; i != NULL; i = i->next) {
1369         delete ((GrDraggable *) i->data);
1370     }
1371     g_slist_free (this->draggables);
1372     this->draggables = NULL;
1373 }
1374
1375 /**
1376 Select the dragger which has the given draggable.
1377 */
1378 GrDragger *
1379 GrDrag::getDraggerFor (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke)
1380 {
1381     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1382         GrDragger *dragger = (GrDragger *) i->data;
1383         for (GSList const* j = dragger->draggables; j != NULL; j = j->next) {
1384             GrDraggable *da2 = (GrDraggable *) j->data;
1385             if ( (da2->item == item) &&
1386                  (point_type == -1 || da2->point_type == point_type) && // -1 means this does not matter
1387                  (point_i == -1 || da2->point_i == point_i) && // -1 means this does not matter
1388                  (da2->fill_or_stroke == fill_or_stroke)) {
1389                 return (dragger);
1390             }
1391         }
1392     }
1393     return NULL;
1394 }
1395
1396
1397 void
1398 GrDragger::moveOtherToDraggable (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, bool write_repr)
1399 {
1400     GrDragger *d = this->parent->getDraggerFor (item, point_type, point_i, fill_or_stroke);
1401     if (d && d !=  this) {
1402         d->moveThisToDraggable (item, point_type, point_i, fill_or_stroke, write_repr);
1403     }
1404 }
1405
1406
1407 /**
1408   Draw this dragger as selected
1409 */
1410 void
1411 GrDragger::select()
1412 {
1413     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_SELECTED;
1414     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_SELECTED, NULL);
1415 }
1416
1417 /**
1418   Draw this dragger as normal (deselected)
1419 */
1420 void
1421 GrDragger::deselect()
1422 {
1423     this->knot->fill [SP_KNOT_STATE_NORMAL] = GR_KNOT_COLOR_NORMAL;
1424     g_object_set (G_OBJECT (this->knot->item), "fill_color", GR_KNOT_COLOR_NORMAL, NULL);
1425 }
1426
1427 bool
1428 GrDragger::isSelected()
1429 {
1430     return g_list_find (parent->selected, this);
1431 }
1432
1433 /**
1434 \brief Deselect all stops/draggers (private)
1435 */
1436 void
1437 GrDrag::deselect_all()
1438 {
1439     while (selected) {
1440         ( (GrDragger*) selected->data)->deselect();
1441         selected = g_list_remove(selected, selected->data);
1442     }
1443 }
1444
1445 /**
1446 \brief Deselect all stops/draggers (public; emits signal)
1447 */
1448 void
1449 GrDrag::deselectAll()
1450 {
1451     deselect_all();
1452     this->desktop->emitToolSubselectionChanged(NULL);
1453 }
1454
1455 /**
1456 \brief Select all stops/draggers
1457 */
1458 void
1459 GrDrag::selectAll()
1460 {
1461     for (GList *l = this->draggers; l != NULL; l = l->next) {
1462         GrDragger *d = ((GrDragger *) l->data);
1463         setSelected (d, true, true);
1464     }
1465 }
1466
1467 /**
1468 \brief Select all stops/draggers that match the coords
1469 */
1470 void
1471 GrDrag::selectByCoords(std::vector<Geom::Point> coords)
1472 {
1473     for (GList *l = this->draggers; l != NULL; l = l->next) {
1474         GrDragger *d = ((GrDragger *) l->data);
1475         for (guint k = 0; k < coords.size(); k++) {
1476             if (Geom::L2 (d->point - coords[k]) < 1e-4) {
1477                 setSelected (d, true, true);
1478             }
1479         }
1480     }
1481 }
1482
1483
1484 /**
1485 \brief Select all stops/draggers that fall within the rect
1486 */
1487 void
1488 GrDrag::selectRect(Geom::Rect const &r)
1489 {
1490     for (GList *l = this->draggers; l != NULL; l = l->next) {
1491         GrDragger *d = ((GrDragger *) l->data);
1492         if (r.contains(d->point)) {
1493            setSelected (d, true, true);
1494         }
1495     }
1496 }
1497
1498 /**
1499 \brief Select a dragger
1500 \param dragger       The dragger to select
1501 \param add_to_selection   If true, add to selection, otherwise deselect others
1502 \param override      If true, always select this node, otherwise toggle selected status
1503 */
1504 void
1505 GrDrag::setSelected (GrDragger *dragger, bool add_to_selection, bool override)
1506 {
1507     GrDragger *seldragger = NULL;
1508
1509     if (add_to_selection) {
1510         if (!dragger) return;
1511         if (override) {
1512             if (!g_list_find(selected, dragger)) {
1513                 selected = g_list_prepend(selected, dragger);
1514             }
1515             dragger->select();
1516             seldragger = dragger;
1517         } else { // toggle
1518             if (g_list_find(selected, dragger)) {
1519                 selected = g_list_remove(selected, dragger);
1520                 dragger->deselect();
1521                 if (selected) {
1522                     seldragger = (GrDragger*) selected->data; // select the dragger that is first in the list
1523                 }
1524             } else {
1525                 selected = g_list_prepend(selected, dragger);
1526                 dragger->select();
1527                 seldragger = dragger;
1528             }
1529         }
1530     } else {
1531         deselect_all();
1532         if (dragger) {
1533             selected = g_list_prepend(selected, dragger);
1534             dragger->select();
1535             seldragger = dragger;
1536         }
1537     }
1538     if (seldragger) {
1539         this->desktop->emitToolSubselectionChanged((gpointer) seldragger);
1540     }
1541 }
1542
1543 /**
1544 \brief Deselect a dragger
1545 \param dragger       The dragger to deselect
1546 */
1547 void
1548 GrDrag::setDeselected (GrDragger *dragger)
1549 {
1550     if (g_list_find(selected, dragger)) {
1551         selected = g_list_remove(selected, dragger);
1552         dragger->deselect();
1553     }
1554     this->desktop->emitToolSubselectionChanged((gpointer) (selected ? selected->data : NULL ));
1555 }
1556
1557
1558
1559 /**
1560 Create a line from p1 to p2 and add it to the lines list
1561  */
1562 void
1563 GrDrag::addLine (SPItem *item, Geom::Point p1, Geom::Point p2, guint32 rgba)
1564 {
1565     SPCanvasItem *line = sp_canvas_item_new(sp_desktop_controls(this->desktop),
1566                                                             SP_TYPE_CTRLLINE, NULL);
1567     sp_canvas_item_move_to_z(line, 0);
1568     SP_CTRLLINE(line)->item = item;
1569     sp_ctrlline_set_coords(SP_CTRLLINE(line), p1, p2);
1570     if (rgba != GR_LINE_COLOR_FILL) // fill is the default, so don't set color for it to speed up redraw
1571         sp_ctrlline_set_rgba32 (SP_CTRLLINE(line), rgba);
1572     sp_canvas_item_show (line);
1573     this->lines = g_slist_append (this->lines, line);
1574 }
1575
1576 /**
1577 If there already exists a dragger within MERGE_DIST of p, add the draggable to it; otherwise create
1578 new dragger and add it to draggers list
1579  */
1580 void
1581 GrDrag::addDragger (GrDraggable *draggable)
1582 {
1583     Geom::Point p = sp_item_gradient_get_coords (draggable->item, draggable->point_type, draggable->point_i, draggable->fill_or_stroke);
1584
1585     for (GList *i = this->draggers; i != NULL; i = i->next) {
1586         GrDragger *dragger = (GrDragger *) i->data;
1587         if (dragger->mayMerge (draggable) && Geom::L2 (dragger->point - p) < MERGE_DIST) {
1588             // distance is small, merge this draggable into dragger, no need to create new dragger
1589             dragger->addDraggable (draggable);
1590             dragger->updateKnotShape();
1591             return;
1592         }
1593     }
1594
1595     GrDragger *new_dragger = new GrDragger(this, p, draggable);
1596     // fixme: draggers should be added AFTER the last one: this way tabbing through them will be from begin to end.
1597     this->draggers = g_list_append (this->draggers, new_dragger);
1598 }
1599
1600 /**
1601 Add draggers for the radial gradient rg on item
1602 */
1603 void
1604 GrDrag::addDraggersRadial (SPRadialGradient *rg, SPItem *item, bool fill_or_stroke)
1605 {
1606     addDragger (new GrDraggable (item, POINT_RG_CENTER, 0, fill_or_stroke));
1607     guint num = rg->vector.stops.size();
1608     if (num > 2) {
1609         for ( guint i = 1; i < num - 1; i++ ) {
1610             addDragger (new GrDraggable (item, POINT_RG_MID1, i, fill_or_stroke));
1611         }
1612     }
1613     addDragger (new GrDraggable (item, POINT_RG_R1, num-1, fill_or_stroke));
1614     if (num > 2) {
1615         for ( guint i = 1; i < num - 1; i++ ) {
1616             addDragger (new GrDraggable (item, POINT_RG_MID2, i, fill_or_stroke));
1617         }
1618     }
1619     addDragger (new GrDraggable (item, POINT_RG_R2, num-1, fill_or_stroke));
1620     addDragger (new GrDraggable (item, POINT_RG_FOCUS, 0, fill_or_stroke));
1621 }
1622
1623 /**
1624 Add draggers for the linear gradient lg on item
1625 */
1626 void
1627 GrDrag::addDraggersLinear (SPLinearGradient *lg, SPItem *item, bool fill_or_stroke)
1628 {
1629     addDragger (new GrDraggable (item, POINT_LG_BEGIN, 0, fill_or_stroke));
1630     guint num = lg->vector.stops.size();
1631     if (num > 2) {
1632         for ( guint i = 1; i < num - 1; i++ ) {
1633             addDragger (new GrDraggable (item, POINT_LG_MID, i, fill_or_stroke));
1634         }
1635     }
1636     addDragger (new GrDraggable (item, POINT_LG_END, num-1, fill_or_stroke));
1637 }
1638
1639 /**
1640 Artificially grab the knot of this dragger; used by the gradient context
1641 */
1642 void
1643 GrDrag::grabKnot (GrDragger *dragger, gint x, gint y, guint32 etime)
1644 {
1645     if (dragger) {
1646         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1647     }
1648 }
1649
1650 /**
1651 Artificially grab the knot of the dragger with this draggable; used by the gradient context
1652 */
1653 void
1654 GrDrag::grabKnot (SPItem *item, gint point_type, gint point_i, bool fill_or_stroke, gint x, gint y, guint32 etime)
1655 {
1656     GrDragger *dragger = getDraggerFor (item, point_type, point_i, fill_or_stroke);
1657     if (dragger) {
1658         sp_knot_start_dragging (dragger->knot, dragger->point, x, y, etime);
1659     }
1660 }
1661
1662 /**
1663 Regenerates the draggers list from the current selection; is called when selection is changed or
1664 modified, also when a radial dragger needs to update positions of other draggers in the gradient
1665 */
1666 void GrDrag::updateDraggers ()
1667 {
1668     while (selected) {
1669         selected = g_list_remove(selected, selected->data);
1670     }
1671     // delete old draggers
1672     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1673         delete static_cast<GrDragger *>(i->data);
1674     }
1675     g_list_free(this->draggers);
1676     this->draggers = NULL;
1677
1678     g_return_if_fail(this->selection != NULL);
1679
1680     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1681         SPItem *item = SP_ITEM(i->data);
1682         SPStyle *style = item->style;
1683
1684         if (style && (style->fill.isPaintserver())) {
1685             SPPaintServer *server = style->getFillPaintServer();
1686             if ( server && server->isSolid() ) {
1687                 // Suppress "gradientness" of solid paint
1688             } else if ( SP_IS_LINEARGRADIENT(server) ) {
1689                 addDraggersLinear( SP_LINEARGRADIENT(server), item, true );
1690             } else if ( SP_IS_RADIALGRADIENT(server) ) {
1691                 addDraggersRadial( SP_RADIALGRADIENT(server), item, true );
1692             }
1693         }
1694
1695         if (style && (style->stroke.isPaintserver())) {
1696             SPPaintServer *server = style->getStrokePaintServer();
1697             if ( server && server->isSolid() ) {
1698                 // Suppress "gradientness" of solid paint
1699             } else if ( SP_IS_LINEARGRADIENT(server) ) {
1700                 addDraggersLinear( SP_LINEARGRADIENT(server), item, false );
1701             } else if ( SP_IS_RADIALGRADIENT(server) ) {
1702                 addDraggersRadial( SP_RADIALGRADIENT(server), item, false );
1703             }
1704         }
1705     }
1706 }
1707
1708
1709 /**
1710  * \brief Returns true if at least one of the draggers' knots has the mouse hovering above it
1711  */
1712
1713 bool
1714 GrDrag::mouseOver()
1715 {
1716     for (GList const* i = this->draggers; i != NULL; i = i->next) {
1717         GrDragger *d = (GrDragger *) i->data;
1718         if (d->knot && (d->knot->flags & SP_KNOT_MOUSEOVER)) {
1719             return true;
1720         }
1721     }
1722     return false;
1723 }
1724 /**
1725 Regenerates the lines list from the current selection; is called on each move of a dragger, so that
1726 lines are always in sync with the actual gradient
1727 */
1728 void
1729 GrDrag::updateLines ()
1730 {
1731     // delete old lines
1732     for (GSList const *i = this->lines; i != NULL; i = i->next) {
1733         gtk_object_destroy( GTK_OBJECT (i->data));
1734     }
1735     g_slist_free (this->lines);
1736     this->lines = NULL;
1737
1738     g_return_if_fail (this->selection != NULL);
1739
1740     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1741
1742         SPItem *item = SP_ITEM(i->data);
1743
1744         SPStyle *style = SP_OBJECT_STYLE (item);
1745
1746         if (style && (style->fill.isPaintserver())) {
1747             SPPaintServer *server = item->style->getFillPaintServer();
1748             if ( server && server->isSolid() ) {
1749                 // Suppress "gradientness" of solid paint
1750             } else if ( SP_IS_LINEARGRADIENT(server) ) {
1751                 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);
1752             } else if ( SP_IS_RADIALGRADIENT(server) ) {
1753                 Geom::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, true);
1754                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, true), GR_LINE_COLOR_FILL);
1755                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, true), GR_LINE_COLOR_FILL);
1756             }
1757         }
1758
1759         if (style && (style->stroke.isPaintserver())) {
1760             SPPaintServer *server = item->style->getStrokePaintServer();
1761             if ( server && server->isSolid() ) {
1762                 // Suppress "gradientness" of solid paint
1763             } else if ( SP_IS_LINEARGRADIENT(server) ) {
1764                 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);
1765             } else if ( SP_IS_RADIALGRADIENT(server) ) {
1766                 Geom::Point center = sp_item_gradient_get_coords (item, POINT_RG_CENTER, 0, false);
1767                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R1, 0, false), GR_LINE_COLOR_STROKE);
1768                 this->addLine (item, center, sp_item_gradient_get_coords (item, POINT_RG_R2, 0, false), GR_LINE_COLOR_STROKE);
1769             }
1770         }
1771     }
1772 }
1773
1774 /**
1775 Regenerates the levels list from the current selection
1776 */
1777 void
1778 GrDrag::updateLevels ()
1779 {
1780     hor_levels.clear();
1781     vert_levels.clear();
1782
1783     g_return_if_fail (this->selection != NULL);
1784
1785     for (GSList const* i = this->selection->itemList(); i != NULL; i = i->next) {
1786         SPItem *item = SP_ITEM(i->data);
1787         Geom::OptRect rect = sp_item_bbox_desktop (item);
1788         if (rect) {
1789             // Remember the edges of the bbox and the center axis
1790             hor_levels.push_back(rect->min()[Geom::Y]);
1791             hor_levels.push_back(rect->max()[Geom::Y]);
1792             hor_levels.push_back(0.5 * (rect->min()[Geom::Y] + rect->max()[Geom::Y]));
1793             vert_levels.push_back(rect->min()[Geom::X]);
1794             vert_levels.push_back(rect->max()[Geom::X]);
1795             vert_levels.push_back(0.5 * (rect->min()[Geom::X] + rect->max()[Geom::X]));
1796         }
1797     }
1798 }
1799
1800 void
1801 GrDrag::selected_reverse_vector ()
1802 {
1803     if (selected == NULL)
1804         return;
1805
1806     for (GSList const* i = ( (GrDragger*) selected->data )->draggables; i != NULL; i = i->next) {
1807         GrDraggable *draggable = (GrDraggable *) i->data;
1808
1809         sp_item_gradient_reverse_vector (draggable->item, draggable->fill_or_stroke);
1810     }
1811 }
1812
1813 void
1814 GrDrag::selected_move_nowrite (double x, double y, bool scale_radial)
1815 {
1816     selected_move (x, y, false, scale_radial);
1817 }
1818
1819 void
1820 GrDrag::selected_move (double x, double y, bool write_repr, bool scale_radial)
1821 {
1822     if (selected == NULL)
1823         return;
1824
1825     bool did = false;
1826
1827     for (GList *i = selected; i != NULL; i = i->next) {
1828         GrDragger *d = (GrDragger *) i->data;
1829
1830         if (!d->isA(POINT_LG_MID) && !d->isA(POINT_RG_MID1) && !d->isA(POINT_RG_MID2)) {
1831             // if this is an endpoint,
1832
1833             // Moving an rg center moves its focus and radii as well.
1834             // therefore, if this is a focus or radius and if selection
1835             // contains the center as well, do not move this one
1836             if (d->isA(POINT_RG_R1) || d->isA(POINT_RG_R2) ||
1837                 (d->isA(POINT_RG_FOCUS) && !d->isA(POINT_RG_CENTER))) {
1838                 bool skip_radius_with_center = false;
1839                 for (GList *di = selected; di != NULL; di = di->next) {
1840                     GrDragger *d_new = (GrDragger *) di->data;
1841                     if (d_new->isA (((GrDraggable *) d->draggables->data)->item,
1842                                     POINT_RG_CENTER,
1843                                     0,
1844                                     ((GrDraggable *) d->draggables->data)->fill_or_stroke)) {
1845                         // FIXME: here we take into account only the first draggable!
1846                         skip_radius_with_center = true;
1847                     }
1848                 }
1849                 if (skip_radius_with_center)
1850                     continue;
1851             }
1852
1853             did = true;
1854             d->point += Geom::Point (x, y);
1855             d->point_original = d->point;
1856             sp_knot_moveto (d->knot, d->point);
1857
1858             d->fireDraggables (write_repr, scale_radial);
1859
1860             d->updateDependencies(write_repr);
1861         }
1862     }
1863
1864     if (write_repr && did) {
1865         // we did an undoable action
1866         sp_document_maybe_done (sp_desktop_document (desktop), "grmoveh", SP_VERB_CONTEXT_GRADIENT,
1867                                 _("Move gradient handle(s)"));
1868         return;
1869     }
1870
1871     if (!did) { // none of the end draggers are selected, so let's try to move the mids
1872
1873         GrDragger *dragger = (GrDragger *) selected->data;
1874         // a midpoint dragger can (logically) only contain one GrDraggable
1875         GrDraggable *draggable = (GrDraggable *) dragger->draggables->data;
1876
1877         Geom::Point begin(0,0), end(0,0);
1878         Geom::Point low_lim(0,0), high_lim(0,0);
1879
1880         SPObject *server = draggable->getServer();
1881         GSList *moving = NULL;
1882         gr_midpoint_limits(dragger, server, &begin, &end, &low_lim, &high_lim, &moving);
1883
1884         Geom::Point p(x, y);
1885         p = snap_vector_midpoint (dragger->point + p, low_lim, high_lim, 0);
1886         Geom::Point displacement = p - dragger->point;
1887
1888         for (GSList const* i = moving; i != NULL; i = i->next) {
1889             GrDragger *drg = (GrDragger*) i->data;
1890             SPKnot *drgknot = drg->knot;
1891             drg->point += displacement;
1892             sp_knot_moveto (drgknot, drg->point);
1893             drg->fireDraggables (true);
1894             drg->updateDependencies(true);
1895             did = true;
1896         }
1897
1898         g_slist_free(moving);
1899
1900         if (write_repr && did) {
1901             // we did an undoable action
1902             sp_document_maybe_done (sp_desktop_document (desktop), "grmovem", SP_VERB_CONTEXT_GRADIENT,
1903                                     _("Move gradient mid stop(s)"));
1904         }
1905     }
1906 }
1907
1908 void
1909 GrDrag::selected_move_screen (double x, double y)
1910 {
1911     gdouble zoom = desktop->current_zoom();
1912     gdouble zx = x / zoom;
1913     gdouble zy = y / zoom;
1914
1915     selected_move (zx, zy);
1916 }
1917
1918 /**
1919 Select the knot next to the last selected one and deselect all other selected.
1920 */
1921 GrDragger *
1922 GrDrag::select_next ()
1923 {
1924     GrDragger *d = NULL;
1925     if (selected == NULL || g_list_find(draggers, selected->data)->next == NULL) {
1926         if (draggers)
1927             d = (GrDragger *) draggers->data;
1928     } else {
1929         d = (GrDragger *) g_list_find(draggers, selected->data)->next->data;
1930     }
1931     if (d)
1932         setSelected (d);
1933     return d;
1934 }
1935
1936 /**
1937 Select the knot previous from the last selected one and deselect all other selected.
1938 */
1939 GrDragger *
1940 GrDrag::select_prev ()
1941 {
1942     GrDragger *d = NULL;
1943     if (selected == NULL || g_list_find(draggers, selected->data)->prev == NULL) {
1944         if (draggers)
1945             d = (GrDragger *) g_list_last (draggers)->data;
1946     } else {
1947         d = (GrDragger *) g_list_find(draggers, selected->data)->prev->data;
1948     }
1949     if (d)
1950         setSelected (d);
1951     return d;
1952 }
1953
1954
1955 // FIXME: i.m.o. an ugly function that I just made to work, but... aargh! (Johan)
1956 void
1957 GrDrag::deleteSelected (bool just_one)
1958 {
1959     if (!selected) return;
1960
1961     SPDocument *document = false;
1962
1963     struct StructStopInfo {
1964         SPStop * spstop;
1965         GrDraggable * draggable;
1966         SPGradient * gradient;
1967         SPGradient * vector;
1968     };
1969
1970     GSList *midstoplist = NULL;  // list of stops that must be deleted (will be deleted first)
1971     GSList *endstoplist = NULL;  // list of stops that must be deleted
1972     while (selected) {
1973         GrDragger *dragger = (GrDragger*) selected->data;
1974         for (GSList * drgble = dragger->draggables; drgble != NULL; drgble = drgble->next) {
1975             GrDraggable *draggable = (GrDraggable*) drgble->data;
1976             SPGradient *gradient = sp_item_gradient (draggable->item, draggable->fill_or_stroke);
1977             SPGradient *vector   = sp_gradient_get_forked_vector_if_necessary (gradient, false);
1978
1979             switch (draggable->point_type) {
1980                 case POINT_LG_MID:
1981                 case POINT_RG_MID1:
1982                 case POINT_RG_MID2:
1983                     {
1984                         SPStop *stop = sp_get_stop_i(vector, draggable->point_i);
1985                         // check if already present in list. (e.g. when both RG_MID1 and RG_MID2 were selected)
1986                         bool present = false;
1987                         for (GSList const * l = midstoplist; l != NULL; l = l->next) {
1988                             if ( (SPStop*)l->data == stop ) {
1989                                 present = true;
1990                                 break; // no need to search further.
1991                             }
1992                         }
1993                         if (!present)
1994                             midstoplist = g_slist_append(midstoplist, stop);
1995                     }
1996                     break;
1997                 case POINT_LG_BEGIN:
1998                 case POINT_LG_END:
1999                 case POINT_RG_CENTER:
2000                 case POINT_RG_R1:
2001                 case POINT_RG_R2:
2002                     {
2003                         SPStop *stop = NULL;
2004                         if ( (draggable->point_type == POINT_LG_BEGIN) || (draggable->point_type == POINT_RG_CENTER) ) {
2005                             stop = vector->getFirstStop();
2006                         } else {
2007                             stop = sp_last_stop(vector);
2008                         }
2009                         if (stop) {
2010                             StructStopInfo *stopinfo = new StructStopInfo;
2011                             stopinfo->spstop = stop;
2012                             stopinfo->draggable = draggable;
2013                             stopinfo->gradient = gradient;
2014                             stopinfo->vector = vector;
2015                             // check if already present in list. (e.g. when both R1 and R2 were selected)
2016                             bool present = false;
2017                             for (GSList const * l = endstoplist; l != NULL; l = l->next) {
2018                                 if ( ((StructStopInfo*)l->data)->spstop == stopinfo->spstop ) {
2019                                     present = true;
2020                                     break; // no need to search further.
2021                                 }
2022                             }
2023                             if (!present)
2024                                 endstoplist = g_slist_append(endstoplist, stopinfo);
2025                         }
2026                     }
2027                     break;
2028                 default:
2029                     break;
2030             }
2031         }
2032         selected = g_list_remove(selected, dragger);
2033         if ( just_one ) break; // iterate once if just_one is set.
2034     }
2035     while (midstoplist) {
2036         SPStop *stop = (SPStop*) midstoplist->data;
2037         document = SP_OBJECT_DOCUMENT (stop);
2038         Inkscape::XML::Node * parent = SP_OBJECT_REPR(stop)->parent();
2039         parent->removeChild(SP_OBJECT_REPR(stop));
2040         midstoplist = g_slist_remove(midstoplist, stop);
2041     }
2042     while (endstoplist) {
2043         StructStopInfo *stopinfo  = (StructStopInfo*) endstoplist->data;
2044         document = SP_OBJECT_DOCUMENT (stopinfo->spstop);
2045
2046         // 2 is the minimum, cannot delete more than that without deleting the whole vector
2047         // cannot use vector->vector.stops.size() because the vector might be invalidated by deletion of a midstop
2048         // manually count the children, don't know if there already exists a function for this...
2049         int len = 0;
2050         for ( SPObject *child = sp_object_first_child(stopinfo->vector) ;
2051               child != NULL ;
2052               child = SP_OBJECT_NEXT(child) )
2053         {
2054             if ( SP_IS_STOP(child) )  len ++;
2055         }
2056         if (len > 2)
2057         {
2058             switch (stopinfo->draggable->point_type) {
2059                 case POINT_LG_BEGIN:
2060                     {
2061                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2062
2063                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
2064                         Geom::Point oldbegin = Geom::Point (lg->x1.computed, lg->y1.computed);
2065                         Geom::Point end = Geom::Point (lg->x2.computed, lg->y2.computed);
2066                         SPStop *stop = stopinfo->vector->getFirstStop();
2067                         gdouble offset = stop->offset;
2068                         Geom::Point newbegin = oldbegin + offset * (end - oldbegin);
2069                         lg->x1.computed = newbegin[Geom::X];
2070                         lg->y1.computed = newbegin[Geom::Y];
2071
2072                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
2073                         sp_repr_set_svg_double(repr, "x1", lg->x1.computed);
2074                         sp_repr_set_svg_double(repr, "y1", lg->y1.computed);
2075                         stop->offset = 0;
2076                         sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", 0);
2077
2078                         // iterate through midstops to set new offset values such that they won't move on canvas.
2079                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2080                         stop = stop->getNextStop();
2081                         while ( stop != laststop ) {
2082                             stop->offset = (stop->offset - offset)/(1 - offset);
2083                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2084                             stop = stop->getNextStop();
2085                         }
2086                     }
2087                     break;
2088                 case POINT_LG_END:
2089                     {
2090                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2091
2092                         SPLinearGradient *lg = SP_LINEARGRADIENT(stopinfo->gradient);
2093                         Geom::Point begin = Geom::Point (lg->x1.computed, lg->y1.computed);
2094                         Geom::Point oldend = Geom::Point (lg->x2.computed, lg->y2.computed);
2095                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2096                         gdouble offset = laststop->offset;
2097                         Geom::Point newend = begin + offset * (oldend - begin);
2098                         lg->x2.computed = newend[Geom::X];
2099                         lg->y2.computed = newend[Geom::Y];
2100
2101                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(stopinfo->gradient);
2102                         sp_repr_set_svg_double(repr, "x2", lg->x2.computed);
2103                         sp_repr_set_svg_double(repr, "y2", lg->y2.computed);
2104                         laststop->offset = 1;
2105                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
2106
2107                         // iterate through midstops to set new offset values such that they won't move on canvas.
2108                         SPStop *stop = stopinfo->vector->getFirstStop();
2109                         stop = stop->getNextStop();
2110                         while ( stop != laststop ) {
2111                             stop->offset = stop->offset / offset;
2112                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2113                             stop = stop->getNextStop();
2114                         }
2115                     }
2116                     break;
2117                 case POINT_RG_CENTER:
2118                     {
2119                         SPStop *newfirst = stopinfo->spstop->getNextStop();
2120                         if (newfirst) {
2121                             newfirst->offset = 0;
2122                             sp_repr_set_css_double (SP_OBJECT_REPR (newfirst), "offset", 0);
2123                         }
2124                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2125                     }
2126                     break;
2127                 case POINT_RG_R1:
2128                 case POINT_RG_R2:
2129                         SP_OBJECT_REPR(stopinfo->vector)->removeChild(SP_OBJECT_REPR(stopinfo->spstop));
2130
2131                         SPRadialGradient *rg = SP_RADIALGRADIENT(stopinfo->gradient);
2132                         double oldradius = rg->r.computed;
2133                         SPStop *laststop = sp_last_stop(stopinfo->vector);
2134                         gdouble offset = laststop->offset;
2135                         double newradius = offset * oldradius;
2136                         rg->r.computed = newradius;
2137
2138                         Inkscape::XML::Node *repr = SP_OBJECT_REPR(rg);
2139                         sp_repr_set_svg_double(repr, "r", rg->r.computed);
2140                         laststop->offset = 1;
2141                         sp_repr_set_css_double (SP_OBJECT_REPR (laststop), "offset", 1);
2142
2143                         // iterate through midstops to set new offset values such that they won't move on canvas.
2144                         SPStop *stop = stopinfo->vector->getFirstStop();
2145                         stop = stop->getNextStop();
2146                         while ( stop != laststop ) {
2147                             stop->offset = stop->offset / offset;
2148                             sp_repr_set_css_double (SP_OBJECT_REPR (stop), "offset", stop->offset);
2149                             stop = stop->getNextStop();
2150                         }
2151                         break;
2152             }
2153         }
2154         else
2155         { // delete the gradient from the object. set fill to unset  FIXME: set to fill of unselected node?
2156             SPCSSAttr *css = sp_repr_css_attr_new ();
2157
2158             // stopinfo->spstop is the selected stop
2159             Inkscape::XML::Node *unselectedrepr = SP_OBJECT_REPR(stopinfo->vector)->firstChild();
2160             if (unselectedrepr == SP_OBJECT_REPR(stopinfo->spstop) ) {
2161                 unselectedrepr = unselectedrepr->next();
2162             }
2163
2164             if (unselectedrepr == NULL) {
2165                 if (stopinfo->draggable->fill_or_stroke) {
2166                     sp_repr_css_unset_property (css, "fill");
2167                 } else {
2168                     sp_repr_css_unset_property (css, "stroke");
2169                 }
2170             } else {
2171                 SPCSSAttr *stopcss = sp_repr_css_attr(unselectedrepr, "style");
2172                 if (stopinfo->draggable->fill_or_stroke) {
2173                     sp_repr_css_set_property(css, "fill", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
2174                     sp_repr_css_set_property(css, "fill-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
2175                 } else {
2176                     sp_repr_css_set_property(css, "stroke", sp_repr_css_property(stopcss, "stop-color", "inkscape:unset"));
2177                     sp_repr_css_set_property(css, "stroke-opacity", sp_repr_css_property(stopcss, "stop-opacity", "1"));
2178                 }
2179                 sp_repr_css_attr_unref (stopcss);
2180             }
2181
2182             sp_repr_css_change (SP_OBJECT_REPR (stopinfo->draggable->item), css, "style");
2183             sp_repr_css_attr_unref (css);
2184         }
2185
2186         endstoplist = g_slist_remove(endstoplist, stopinfo);
2187         delete stopinfo;
2188     }
2189
2190     if (document) {
2191         sp_document_done ( document, SP_VERB_CONTEXT_GRADIENT, _("Delete gradient stop(s)") );
2192     }
2193 }
2194
2195
2196 /*
2197   Local Variables:
2198   mode:c++
2199   c-file-style:"stroustrup"
2200   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
2201   indent-tabs-mode:nil
2202   fill-column:99
2203   End:
2204 */
2205 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :