src/pen-context.cpp

   1 /** \file
   2  * Pen event context implementation.
   3  */
   4
   5 /*
   6  * Authors:
   7  *   Lauris Kaplinski <lauris@kaplinski.com>
   8  *   bulia byak <buliabyak@users.sf.net>
   9  *
  10  * Copyright (C) 2000 Lauris Kaplinski
  11  * Copyright (C) 2000-2001 Ximian, Inc.
  12  * Copyright (C) 2002 Lauris Kaplinski
  13  * Copyright (C) 2004 Monash University
  14  *
  15  * Released under GNU GPL, read the file 'COPYING' for more information
  16  */
  17
  18 #include <gdk/gdkkeysyms.h>
  19 #include <cstring>
  20 #include <string>
  21
  22 #include "pen-context.h"
  23 #include "sp-namedview.h"
  24 #include "sp-metrics.h"
  25 #include "desktop.h"
  26 #include "desktop-handles.h"
  27 #include "selection.h"
  28 #include "selection-chemistry.h"
  29 #include "draw-anchor.h"
  30 #include "message-stack.h"
  31 #include "message-context.h"
  32 #include "preferences.h"
  33 #include "sp-path.h"
  34 #include "display/curve.h"
  35 #include "pixmaps/cursor-pen.xpm"
  36 #include "display/canvas-bpath.h"
  37 #include "display/sp-ctrlline.h"
  38 #include "display/sodipodi-ctrl.h"
  39 #include <glibmm/i18n.h>
  40 #include "libnr/nr-point-ops.h"
  41 #include "helper/units.h"
  42 #include "macros.h"
  43 #include "context-fns.h"
  44 #include "tools-switch.h"
  45
  46 static void sp_pen_context_class_init(SPPenContextClass *klass);
  47 static void sp_pen_context_init(SPPenContext *pc);
  48 static void sp_pen_context_dispose(GObject *object);
  49
  50 static void sp_pen_context_setup(SPEventContext *ec);
  51 static void sp_pen_context_finish(SPEventContext *ec);
  52 static void sp_pen_context_set(SPEventContext *ec, Inkscape::Preferences::Entry *val);
  53 static gint sp_pen_context_root_handler(SPEventContext *ec, GdkEvent *event);
  54 static gint sp_pen_context_item_handler(SPEventContext *event_context, SPItem *item, GdkEvent *event);
  55
  56 static void spdc_pen_set_initial_point(SPPenContext *pc, Geom::Point const p);
  57 static void spdc_pen_set_subsequent_point(SPPenContext *const pc, Geom::Point const p, bool statusbar, guint status = 0);
  58 static void spdc_pen_set_ctrl(SPPenContext *pc, Geom::Point const p, guint state);
  59 static void spdc_pen_finish_segment(SPPenContext *pc, Geom::Point p, guint state);
  60
  61 static void spdc_pen_finish(SPPenContext *pc, gboolean closed);
  62
  63 static gint pen_handle_button_press(SPPenContext *const pc, GdkEventButton const &bevent);
  64 static gint pen_handle_motion_notify(SPPenContext *const pc, GdkEventMotion const &mevent);
  65 static gint pen_handle_button_release(SPPenContext *const pc, GdkEventButton const &revent);
  66 static gint pen_handle_2button_press(SPPenContext *const pc, GdkEventButton const &bevent);
  67 static gint pen_handle_key_press(SPPenContext *const pc, GdkEvent *event);
  68 static void spdc_reset_colors(SPPenContext *pc);
  69
  70 static void pen_disable_events(SPPenContext *const pc);
  71 static void pen_enable_events(SPPenContext *const pc);
  72
  73 static Geom::Point pen_drag_origin_w(0, 0);
  74 static bool pen_within_tolerance = false;
  75
  76 static SPDrawContextClass *pen_parent_class;
  77
  78 static int pen_next_paraxial_direction(const SPPenContext *const pc, Geom::Point const &pt, Geom::Point const &origin, guint state);
  79 static void pen_set_to_nearest_horiz_vert(const SPPenContext *const pc, Geom::Point &pt, guint const state, bool snap);
  80
  81 static int pen_last_paraxial_dir = 0; // last used direction in horizontal/vertical mode; 0 = horizontal, 1 = vertical
  82
  83 /**
  84  * Register SPPenContext with Gdk and return its type.
  85  */
  86 GType
  87 sp_pen_context_get_type(void)
  88 {
  89     static GType type = 0;
  90     if (!type) {
  91         GTypeInfo info = {
  92             sizeof(SPPenContextClass),
  93             NULL, NULL,
  94             (GClassInitFunc) sp_pen_context_class_init,
  95             NULL, NULL,
  96             sizeof(SPPenContext),
  97             4,
  98             (GInstanceInitFunc) sp_pen_context_init,
  99             NULL,   /* value_table */
 100         };
 101         type = g_type_register_static(SP_TYPE_DRAW_CONTEXT, "SPPenContext", &info, (GTypeFlags)0);
 102     }
 103     return type;
 104 }
 105
 106 /**
 107  * Initialize the SPPenContext vtable.
 108  */
 109 static void
 110 sp_pen_context_class_init(SPPenContextClass *klass)
 111 {
 112     GObjectClass *object_class;
 113     SPEventContextClass *event_context_class;
 114
 115     object_class = (GObjectClass *) klass;
 116     event_context_class = (SPEventContextClass *) klass;
 117
 118     pen_parent_class = (SPDrawContextClass*)g_type_class_peek_parent(klass);
 119
 120     object_class->dispose = sp_pen_context_dispose;
 121
 122     event_context_class->setup = sp_pen_context_setup;
 123     event_context_class->finish = sp_pen_context_finish;
 124     event_context_class->set = sp_pen_context_set;
 125     event_context_class->root_handler = sp_pen_context_root_handler;
 126     event_context_class->item_handler = sp_pen_context_item_handler;
 127 }
 128
 129 /**
 130  * Callback to initialize SPPenContext object.
 131  */
 132 static void
 133 sp_pen_context_init(SPPenContext *pc)
 134 {
 135
 136     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 137
 138     event_context->cursor_shape = cursor_pen_xpm;
 139     event_context->hot_x = 4;
 140     event_context->hot_y = 4;
 141
 142     pc->npoints = 0;
 143     pc->mode = SP_PEN_CONTEXT_MODE_CLICK;
 144     pc->state = SP_PEN_CONTEXT_POINT;
 145
 146     pc->c0 = NULL;
 147     pc->c1 = NULL;
 148     pc->cl0 = NULL;
 149     pc->cl1 = NULL;
 150
 151     pc->events_disabled = 0;
 152
 153     pc->num_clicks = 0;
 154     pc->waiting_LPE = NULL;
 155     pc->waiting_item = NULL;
 156 }
 157
 158 /**
 159  * Callback to destroy the SPPenContext object's members and itself.
 160  */
 161 static void
 162 sp_pen_context_dispose(GObject *object)
 163 {
 164     SPPenContext *pc;
 165
 166     pc = SP_PEN_CONTEXT(object);
 167
 168     if (pc->c0) {
 169         gtk_object_destroy(GTK_OBJECT(pc->c0));
 170         pc->c0 = NULL;
 171     }
 172     if (pc->c1) {
 173         gtk_object_destroy(GTK_OBJECT(pc->c1));
 174         pc->c1 = NULL;
 175     }
 176     if (pc->cl0) {
 177         gtk_object_destroy(GTK_OBJECT(pc->cl0));
 178         pc->cl0 = NULL;
 179     }
 180     if (pc->cl1) {
 181         gtk_object_destroy(GTK_OBJECT(pc->cl1));
 182         pc->cl1 = NULL;
 183     }
 184
 185     G_OBJECT_CLASS(pen_parent_class)->dispose(object);
 186
 187     if (pc->expecting_clicks_for_LPE > 0) {
 188         // we received too few clicks to sanely set the parameter path so we remove the LPE from the item
 189         sp_lpe_item_remove_current_path_effect(pc->waiting_item, false);
 190     }
 191 }
 192
 193 void
 194 sp_pen_context_set_polyline_mode(SPPenContext *const pc) {
 195     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 196     guint mode = prefs->getInt("/tools/freehand/pen/freehand-mode", 0);
 197     pc->polylines_only = (mode == 2 || mode == 3);
 198     pc->polylines_paraxial = (mode == 3);
 199 }
 200
 201 /**
 202  * Callback to initialize SPPenContext object.
 203  */
 204 static void
 205 sp_pen_context_setup(SPEventContext *ec)
 206 {
 207     SPPenContext *pc;
 208
 209     pc = SP_PEN_CONTEXT(ec);
 210
 211     if (((SPEventContextClass *) pen_parent_class)->setup) {
 212         ((SPEventContextClass *) pen_parent_class)->setup(ec);
 213     }
 214
 215     /* Pen indicators */
 216     pc->c0 = sp_canvas_item_new(sp_desktop_controls(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRL, "shape", SP_CTRL_SHAPE_CIRCLE,
 217                                 "size", 4.0, "filled", 0, "fill_color", 0xff00007f, "stroked", 1, "stroke_color", 0x0000ff7f, NULL);
 218     pc->c1 = sp_canvas_item_new(sp_desktop_controls(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRL, "shape", SP_CTRL_SHAPE_CIRCLE,
 219                                 "size", 4.0, "filled", 0, "fill_color", 0xff00007f, "stroked", 1, "stroke_color", 0x0000ff7f, NULL);
 220     pc->cl0 = sp_canvas_item_new(sp_desktop_controls(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRLLINE, NULL);
 221     sp_ctrlline_set_rgba32(SP_CTRLLINE(pc->cl0), 0x0000007f);
 222     pc->cl1 = sp_canvas_item_new(sp_desktop_controls(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRLLINE, NULL);
 223     sp_ctrlline_set_rgba32(SP_CTRLLINE(pc->cl1), 0x0000007f);
 224
 225     sp_canvas_item_hide(pc->c0);
 226     sp_canvas_item_hide(pc->c1);
 227     sp_canvas_item_hide(pc->cl0);
 228     sp_canvas_item_hide(pc->cl1);
 229
 230     sp_event_context_read(ec, "mode");
 231
 232     pc->anchor_statusbar = false;
 233
 234     sp_pen_context_set_polyline_mode(pc);
 235
 236     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 237     if (prefs->getBool("/tools/freehand/pen/selcue")) {
 238         ec->enableSelectionCue();
 239     }
 240 }
 241
 242 static void
 243 pen_cancel (SPPenContext *const pc)
 244 {
 245     pc->num_clicks = 0;
 246     pc->state = SP_PEN_CONTEXT_STOP;
 247     spdc_reset_colors(pc);
 248     sp_canvas_item_hide(pc->c0);
 249     sp_canvas_item_hide(pc->c1);
 250     sp_canvas_item_hide(pc->cl0);
 251     sp_canvas_item_hide(pc->cl1);
 252     pc->_message_context->clear();
 253     pc->_message_context->flash(Inkscape::NORMAL_MESSAGE, _("Drawing cancelled"));
 254
 255     sp_canvas_end_forced_full_redraws(pc->desktop->canvas);
 256 }
 257
 258 /**
 259  * Finalization callback.
 260  */
 261 static void
 262 sp_pen_context_finish(SPEventContext *ec)
 263 {
 264     SPPenContext *pc = SP_PEN_CONTEXT(ec);
 265
 266     sp_event_context_discard_delayed_snap_event(ec);
 267
 268     if (pc->npoints != 0) {
 269         pen_cancel (pc);
 270     }
 271
 272     if (((SPEventContextClass *) pen_parent_class)->finish) {
 273         ((SPEventContextClass *) pen_parent_class)->finish(ec);
 274     }
 275 }
 276
 277 /**
 278  * Callback that sets key to value in pen context.
 279  */
 280 static void
 281 sp_pen_context_set(SPEventContext *ec, Inkscape::Preferences::Entry *val)
 282 {
 283     SPPenContext *pc = SP_PEN_CONTEXT(ec);
 284     Glib::ustring name = val->getEntryName();
 285
 286     if (name == "mode") {
 287         if ( val->getString() == "drag" ) {
 288             pc->mode = SP_PEN_CONTEXT_MODE_DRAG;
 289         } else {
 290             pc->mode = SP_PEN_CONTEXT_MODE_CLICK;
 291         }
 292     }
 293 }
 294
 295 /**
 296  * Snaps new node relative to the previous node.
 297  */
 298 static void
 299 spdc_endpoint_snap(SPPenContext const *const pc, Geom::Point &p, guint const state)
 300 {
 301     if ((state & GDK_CONTROL_MASK) && !pc->polylines_paraxial) { //CTRL enables angular snapping
 302         if (pc->npoints > 0) {
 303             spdc_endpoint_snap_rotation(pc, p, pc->p[0], state);
 304         }
 305     } else {
 306         // We cannot use shift here to disable snapping because the shift-key is already used
 307         // to toggle the paraxial direction; if the user wants to disable snapping (s)he will
 308         // have to use the %-key, the menu, or the snap toolbar
 309         if ((pc->npoints > 0) && pc->polylines_paraxial) {
 310             // snap constrained
 311             pen_set_to_nearest_horiz_vert(pc, p, state, true);
 312         } else {
 313             // snap freely
 314             spdc_endpoint_snap_free(pc, p, state);
 315         }
 316     }
 317 }
 318
 319 /**
 320  * Snaps new node's handle relative to the new node.
 321  */
 322 static void
 323 spdc_endpoint_snap_handle(SPPenContext const *const pc, Geom::Point &p, guint const state)
 324 {
 325     g_return_if_fail(( pc->npoints == 2 ||
 326                        pc->npoints == 5   ));
 327
 328     if ((state & GDK_CONTROL_MASK)) { //CTRL enables angular snapping
 329         spdc_endpoint_snap_rotation(pc, p, pc->p[pc->npoints - 2], state);
 330     } else {
 331         if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above
 332             spdc_endpoint_snap_free(pc, p, state);
 333         }
 334     }
 335 }
 336
 337 static gint
 338 sp_pen_context_item_handler(SPEventContext *ec, SPItem *item, GdkEvent *event)
 339 {
 340     SPPenContext *const pc = SP_PEN_CONTEXT(ec);
 341
 342     gint ret = FALSE;
 343
 344     switch (event->type) {
 345         case GDK_BUTTON_PRESS:
 346             ret = pen_handle_button_press(pc, event->button);
 347             break;
 348         case GDK_BUTTON_RELEASE:
 349             ret = pen_handle_button_release(pc, event->button);
 350             break;
 351         default:
 352             break;
 353     }
 354
 355     if (!ret) {
 356         if (((SPEventContextClass *) pen_parent_class)->item_handler)
 357             ret = ((SPEventContextClass *) pen_parent_class)->item_handler(ec, item, event);
 358     }
 359
 360     return ret;
 361 }
 362
 363 /**
 364  * Callback to handle all pen events.
 365  */
 366 static gint
 367 sp_pen_context_root_handler(SPEventContext *ec, GdkEvent *event)
 368 {
 369     SPPenContext *const pc = SP_PEN_CONTEXT(ec);
 370
 371     gint ret = FALSE;
 372
 373     switch (event->type) {
 374         case GDK_BUTTON_PRESS:
 375             ret = pen_handle_button_press(pc, event->button);
 376             break;
 377
 378         case GDK_MOTION_NOTIFY:
 379             ret = pen_handle_motion_notify(pc, event->motion);
 380             break;
 381
 382         case GDK_BUTTON_RELEASE:
 383             ret = pen_handle_button_release(pc, event->button);
 384             break;
 385
 386         case GDK_2BUTTON_PRESS:
 387             ret = pen_handle_2button_press(pc, event->button);
 388             break;
 389
 390         case GDK_KEY_PRESS:
 391             ret = pen_handle_key_press(pc, event);
 392             break;
 393
 394         default:
 395             break;
 396     }
 397
 398     if (!ret) {
 399         gint (*const parent_root_handler)(SPEventContext *, GdkEvent *)
 400             = ((SPEventContextClass *) pen_parent_class)->root_handler;
 401         if (parent_root_handler) {
 402             ret = parent_root_handler(ec, event);
 403         }
 404     }
 405
 406     return ret;
 407 }
 408
 409 /**
 410  * Handle mouse button press event.
 411  */
 412 static gint pen_handle_button_press(SPPenContext *const pc, GdkEventButton const &bevent)
 413 {
 414     if (pc->events_disabled) {
 415         // skip event processing if events are disabled
 416         return FALSE;
 417     }
 418
 419     SPDrawContext * const dc = SP_DRAW_CONTEXT(pc);
 420     SPDesktop * const desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 421     Geom::Point const event_w(bevent.x, bevent.y);
 422     Geom::Point event_dt(desktop->w2d(event_w));
 423     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 424
 425     gint ret = FALSE;
 426     if (bevent.button == 1 && !event_context->space_panning
 427         // make sure this is not the last click for a waiting LPE (otherwise we want to finish the path)
 428         && pc->expecting_clicks_for_LPE != 1) {
 429
 430         if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 431             return TRUE;
 432         }
 433
 434         if (!pc->grab ) {
 435             /* Grab mouse, so release will not pass unnoticed */
 436             pc->grab = SP_CANVAS_ITEM(desktop->acetate);
 437             sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK   |
 438                                             GDK_BUTTON_RELEASE_MASK |
 439                                             GDK_POINTER_MOTION_MASK  ),
 440                                 NULL, bevent.time);
 441         }
 442
 443         pen_drag_origin_w = event_w;
 444         pen_within_tolerance = true;
 445
 446         /* Test whether we hit any anchor. */
 447         SPDrawAnchor * const anchor = spdc_test_inside(pc, event_w);
 448
 449         switch (pc->mode) {
 450             case SP_PEN_CONTEXT_MODE_CLICK:
 451                 /* In click mode we add point on release */
 452                 switch (pc->state) {
 453                     case SP_PEN_CONTEXT_POINT:
 454                     case SP_PEN_CONTEXT_CONTROL:
 455                     case SP_PEN_CONTEXT_CLOSE:
 456                         break;
 457                     case SP_PEN_CONTEXT_STOP:
 458                         /* This is allowed, if we just canceled curve */
 459                         pc->state = SP_PEN_CONTEXT_POINT;
 460                         break;
 461                     default:
 462                         break;
 463                 }
 464                 break;
 465             case SP_PEN_CONTEXT_MODE_DRAG:
 466                 switch (pc->state) {
 467                     case SP_PEN_CONTEXT_STOP:
 468                         /* This is allowed, if we just canceled curve */
 469                     case SP_PEN_CONTEXT_POINT:
 470                         if (pc->npoints == 0) {
 471
 472                             Geom::Point p;
 473                             if ((bevent.state & GDK_CONTROL_MASK) && (pc->polylines_only || pc->polylines_paraxial)) {
 474                                 p = event_dt;
 475                                 if (!(bevent.state & GDK_SHIFT_MASK)) {
 476                                     SnapManager &m = desktop->namedview->snap_manager;
 477                                     m.setup(desktop);
 478                                     m.freeSnapReturnByRef(p, Inkscape::SNAPSOURCE_NODE_HANDLE);
 479                                     m.unSetup();
 480                                 }
 481                               spdc_create_single_dot(event_context, p, "/tools/freehand/pen", bevent.state);
 482                               ret = TRUE;
 483                               break;
 484                             }
 485
 486                             // TODO: Perhaps it would be nicer to rearrange the following case
 487                             // distinction so that the case of a waiting LPE is treated separately
 488
 489                             /* Set start anchor */
 490                             pc->sa = anchor;
 491                             if (anchor && !sp_pen_context_has_waiting_LPE(pc)) {
 492                                 /* Adjust point to anchor if needed; if we have a waiting LPE, we need
 493                                    a fresh path to be created so don't continue an existing one */
 494                                 p = anchor->dp;
 495                                 desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Continuing selected path"));
 496                             } else {
 497                                 // This is the first click of a new curve; deselect item so that
 498                                 // this curve is not combined with it (unless it is drawn from its
 499                                 // anchor, which is handled by the sibling branch above)
 500                                 Inkscape::Selection * const selection = sp_desktop_selection(desktop);
 501                                 if (!(bevent.state & GDK_SHIFT_MASK) || sp_pen_context_has_waiting_LPE(pc)) {
 502                                     /* if we have a waiting LPE, we need a fresh path to be created
 503                                        so don't append to an existing one */
 504                                     selection->clear();
 505                                     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Creating new path"));
 506                                 } else if (selection->singleItem() && SP_IS_PATH(selection->singleItem())) {
 507                                     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Appending to selected path"));
 508                                 }
 509
 510                                 /* Create green anchor */
 511                                 p = event_dt;
 512                                 spdc_endpoint_snap(pc, p, bevent.state);
 513                                 pc->green_anchor = sp_draw_anchor_new(pc, pc->green_curve, TRUE, p);
 514                             }
 515                             spdc_pen_set_initial_point(pc, p);
 516                         } else {
 517
 518                             /* Set end anchor */
 519                             pc->ea = anchor;
 520                             Geom::Point p;
 521                             if (anchor) {
 522                                 p = anchor->dp;
 523                                 // we hit an anchor, will finish the curve (either with or without closing)
 524                                 // in release handler
 525                                 pc->state = SP_PEN_CONTEXT_CLOSE;
 526
 527                                 if (pc->green_anchor && pc->green_anchor->active) {
 528                                     // we clicked on the current curve start, so close it even if
 529                                     // we drag a handle away from it
 530                                     dc->green_closed = TRUE;
 531                                 }
 532                                 ret = TRUE;
 533                                 break;
 534
 535                             } else {
 536                                 p = event_dt;
 537                                 spdc_endpoint_snap(pc, p, bevent.state); /* Snap node only if not hitting anchor. */
 538                                 spdc_pen_set_subsequent_point(pc, p, true);
 539                             }
 540                         }
 541
 542                         pc->state = pc->polylines_only ? SP_PEN_CONTEXT_POINT : SP_PEN_CONTEXT_CONTROL;
 543                         ret = TRUE;
 544                         break;
 545                     case SP_PEN_CONTEXT_CONTROL:
 546                         g_warning("Button down in CONTROL state");
 547                         break;
 548                     case SP_PEN_CONTEXT_CLOSE:
 549                         g_warning("Button down in CLOSE state");
 550                         break;
 551                     default:
 552                         break;
 553                 }
 554                 break;
 555             default:
 556                 break;
 557         }
 558     } else if (pc->expecting_clicks_for_LPE == 1 && pc->npoints != 0) {
 559         // when the last click for a waiting LPE occurs we want to finish the path
 560         spdc_pen_finish_segment(pc, event_dt, bevent.state);
 561         if (pc->green_closed) {
 562             // finishing at the start anchor, close curve
 563             spdc_pen_finish(pc, TRUE);
 564         } else {
 565             // finishing at some other anchor, finish curve but not close
 566             spdc_pen_finish(pc, FALSE);
 567         }
 568
 569         ret = TRUE;
 570     } else if (bevent.button == 3 && pc->npoints != 0) {
 571         // right click - finish path
 572         spdc_pen_finish(pc, FALSE);
 573         ret = TRUE;
 574     }
 575
 576     if (pc->expecting_clicks_for_LPE > 0) {
 577         --pc->expecting_clicks_for_LPE;
 578     }
 579
 580     return ret;
 581 }
 582
 583 /**
 584  * Handle motion_notify event.
 585  */
 586 static gint
 587 pen_handle_motion_notify(SPPenContext *const pc, GdkEventMotion const &mevent)
 588 {
 589     gint ret = FALSE;
 590
 591     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 592     SPDesktop * const dt = SP_EVENT_CONTEXT_DESKTOP(event_context);
 593
 594     if (event_context->space_panning || mevent.state & GDK_BUTTON2_MASK || mevent.state & GDK_BUTTON3_MASK) {
 595         // allow scrolling
 596         return FALSE;
 597     }
 598
 599     if (pc->events_disabled) {
 600         // skip motion events if pen events are disabled
 601         return FALSE;
 602     }
 603
 604     Geom::Point const event_w(mevent.x,
 605                             mevent.y);
 606     if (pen_within_tolerance) {
 607         Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 608         gint const tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
 609         if ( Geom::LInfty( event_w - pen_drag_origin_w ) < tolerance ) {
 610             return FALSE;   // Do not drag if we're within tolerance from origin.
 611         }
 612     }
 613     // Once the user has moved farther than tolerance from the original location
 614     // (indicating they intend to move the object, not click), then always process the
 615     // motion notify coordinates as given (no snapping back to origin)
 616     pen_within_tolerance = false;
 617
 618     /* Find desktop coordinates */
 619     Geom::Point p = dt->w2d(event_w);
 620
 621     /* Test, whether we hit any anchor */
 622     SPDrawAnchor *anchor = spdc_test_inside(pc, event_w);
 623
 624     switch (pc->mode) {
 625         case SP_PEN_CONTEXT_MODE_CLICK:
 626             switch (pc->state) {
 627                 case SP_PEN_CONTEXT_POINT:
 628                     if ( pc->npoints != 0 ) {
 629                         /* Only set point, if we are already appending */
 630                         spdc_endpoint_snap(pc, p, mevent.state);
 631                         spdc_pen_set_subsequent_point(pc, p, true);
 632                         ret = TRUE;
 633                     } else if (!sp_event_context_knot_mouseover(pc)) {
 634                         SnapManager &m = dt->namedview->snap_manager;
 635                         m.setup(dt);
 636                         m.preSnap(Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_NODE_HANDLE));
 637                         m.unSetup();
 638                     }
 639                     break;
 640                 case SP_PEN_CONTEXT_CONTROL:
 641                 case SP_PEN_CONTEXT_CLOSE:
 642                     /* Placing controls is last operation in CLOSE state */
 643                     spdc_endpoint_snap(pc, p, mevent.state);
 644                     spdc_pen_set_ctrl(pc, p, mevent.state);
 645                     ret = TRUE;
 646                     break;
 647                 case SP_PEN_CONTEXT_STOP:
 648                     /* This is perfectly valid */
 649                     break;
 650                 default:
 651                     break;
 652             }
 653             break;
 654         case SP_PEN_CONTEXT_MODE_DRAG:
 655             switch (pc->state) {
 656                 case SP_PEN_CONTEXT_POINT:
 657                     if ( pc->npoints > 0 ) {
 658                         /* Only set point, if we are already appending */
 659
 660                         if (!anchor) {   /* Snap node only if not hitting anchor */
 661                             spdc_endpoint_snap(pc, p, mevent.state);
 662                             spdc_pen_set_subsequent_point(pc, p, true, mevent.state);
 663                         } else {
 664                             spdc_pen_set_subsequent_point(pc, anchor->dp, false, mevent.state);
 665                         }
 666
 667                         if (anchor && !pc->anchor_statusbar) {
 668                             pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to close and finish the path."));
 669                             pc->anchor_statusbar = true;
 670                         } else if (!anchor && pc->anchor_statusbar) {
 671                             pc->_message_context->clear();
 672                             pc->anchor_statusbar = false;
 673                         }
 674
 675                         ret = TRUE;
 676                     } else {
 677                         if (anchor && !pc->anchor_statusbar) {
 678                             pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to continue the path from this point."));
 679                             pc->anchor_statusbar = true;
 680                         } else if (!anchor && pc->anchor_statusbar) {
 681                             pc->_message_context->clear();
 682                             pc->anchor_statusbar = false;
 683                         }
 684                         if (!sp_event_context_knot_mouseover(pc)) {
 685                             SnapManager &m = dt->namedview->snap_manager;
 686                             m.setup(dt);
 687                             m.preSnap(Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_NODE_HANDLE));
 688                             m.unSetup();
 689                         }
 690                     }
 691                     break;
 692                 case SP_PEN_CONTEXT_CONTROL:
 693                 case SP_PEN_CONTEXT_CLOSE:
 694                     /* Placing controls is last operation in CLOSE state */
 695
 696                     // snap the handle
 697                     spdc_endpoint_snap_handle(pc, p, mevent.state);
 698
 699                     if (!pc->polylines_only) {
 700                         spdc_pen_set_ctrl(pc, p, mevent.state);
 701                     } else {
 702                         spdc_pen_set_ctrl(pc, pc->p[1], mevent.state);
 703                     }
 704                     gobble_motion_events(GDK_BUTTON1_MASK);
 705                     ret = TRUE;
 706                     break;
 707                 case SP_PEN_CONTEXT_STOP:
 708                     /* This is perfectly valid */
 709                     break;
 710                 default:
 711                     if (!sp_event_context_knot_mouseover(pc)) {
 712                         SnapManager &m = dt->namedview->snap_manager;
 713                         m.setup(dt);
 714                         m.preSnap(Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_NODE_HANDLE));
 715                         m.unSetup();
 716                     }
 717                     break;
 718             }
 719             break;
 720         default:
 721             break;
 722     }
 723     return ret;
 724 }
 725
 726 /**
 727  * Handle mouse button release event.
 728  */
 729 static gint
 730 pen_handle_button_release(SPPenContext *const pc, GdkEventButton const &revent)
 731 {
 732     if (pc->events_disabled) {
 733         // skip event processing if events are disabled
 734         return FALSE;
 735     }
 736
 737     gint ret = FALSE;
 738     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 739     if ( revent.button == 1  && !event_context->space_panning) {
 740
 741         SPDrawContext *dc = SP_DRAW_CONTEXT (pc);
 742
 743         Geom::Point const event_w(revent.x,
 744                                 revent.y);
 745         /* Find desktop coordinates */
 746         Geom::Point p = pc->desktop->w2d(event_w);
 747
 748         /* Test whether we hit any anchor. */
 749         SPDrawAnchor *anchor = spdc_test_inside(pc, event_w);
 750
 751         switch (pc->mode) {
 752             case SP_PEN_CONTEXT_MODE_CLICK:
 753                 switch (pc->state) {
 754                     case SP_PEN_CONTEXT_POINT:
 755                         if ( pc->npoints == 0 ) {
 756                             /* Start new thread only with button release */
 757                             if (anchor) {
 758                                 p = anchor->dp;
 759                             }
 760                             pc->sa = anchor;
 761                             spdc_pen_set_initial_point(pc, p);
 762                         } else {
 763                             /* Set end anchor here */
 764                             pc->ea = anchor;
 765                             if (anchor) {
 766                                 p = anchor->dp;
 767                             }
 768                         }
 769                         pc->state = SP_PEN_CONTEXT_CONTROL;
 770                         ret = TRUE;
 771                         break;
 772                     case SP_PEN_CONTEXT_CONTROL:
 773                         /* End current segment */
 774                         spdc_endpoint_snap(pc, p, revent.state);
 775                         spdc_pen_finish_segment(pc, p, revent.state);
 776                         pc->state = SP_PEN_CONTEXT_POINT;
 777                         ret = TRUE;
 778                         break;
 779                     case SP_PEN_CONTEXT_CLOSE:
 780                         /* End current segment */
 781                         if (!anchor) {   /* Snap node only if not hitting anchor */
 782                             spdc_endpoint_snap(pc, p, revent.state);
 783                         }
 784                         spdc_pen_finish_segment(pc, p, revent.state);
 785                         spdc_pen_finish(pc, TRUE);
 786                         pc->state = SP_PEN_CONTEXT_POINT;
 787                         ret = TRUE;
 788                         break;
 789                     case SP_PEN_CONTEXT_STOP:
 790                         /* This is allowed, if we just canceled curve */
 791                         pc->state = SP_PEN_CONTEXT_POINT;
 792                         ret = TRUE;
 793                         break;
 794                     default:
 795                         break;
 796                 }
 797                 break;
 798             case SP_PEN_CONTEXT_MODE_DRAG:
 799                 switch (pc->state) {
 800                     case SP_PEN_CONTEXT_POINT:
 801                     case SP_PEN_CONTEXT_CONTROL:
 802                         spdc_endpoint_snap(pc, p, revent.state);
 803                         spdc_pen_finish_segment(pc, p, revent.state);
 804                         break;
 805                     case SP_PEN_CONTEXT_CLOSE:
 806                         spdc_endpoint_snap(pc, p, revent.state);
 807                         spdc_pen_finish_segment(pc, p, revent.state);
 808                         if (pc->green_closed) {
 809                             // finishing at the start anchor, close curve
 810                             spdc_pen_finish(pc, TRUE);
 811                         } else {
 812                             // finishing at some other anchor, finish curve but not close
 813                             spdc_pen_finish(pc, FALSE);
 814                         }
 815                         break;
 816                     case SP_PEN_CONTEXT_STOP:
 817                         /* This is allowed, if we just cancelled curve */
 818                         break;
 819                     default:
 820                         break;
 821                 }
 822                 pc->state = SP_PEN_CONTEXT_POINT;
 823                 ret = TRUE;
 824                 break;
 825             default:
 826                 break;
 827         }
 828
 829         if (pc->grab) {
 830             /* Release grab now */
 831             sp_canvas_item_ungrab(pc->grab, revent.time);
 832             pc->grab = NULL;
 833         }
 834
 835         ret = TRUE;
 836
 837         dc->green_closed = FALSE;
 838     }
 839
 840     // TODO: can we be sure that the path was created correctly?
 841     // TODO: should we offer an option to collect the clicks in a list?
 842     if (pc->expecting_clicks_for_LPE == 0 && sp_pen_context_has_waiting_LPE(pc)) {
 843         sp_pen_context_set_polyline_mode(pc);
 844
 845         SPEventContext *ec = SP_EVENT_CONTEXT(pc);
 846         Inkscape::Selection *selection = sp_desktop_selection (ec->desktop);
 847
 848         if (pc->waiting_LPE) {
 849             // we have an already created LPE waiting for a path
 850             pc->waiting_LPE->acceptParamPath(SP_PATH(selection->singleItem()));
 851             selection->add(SP_OBJECT(pc->waiting_item));
 852             pc->waiting_LPE = NULL;
 853         } else {
 854             // the case that we need to create a new LPE and apply it to the just-drawn path is
 855             // handled in spdc_check_for_and_apply_waiting_LPE() in draw-context.cpp
 856         }
 857     }
 858
 859     return ret;
 860 }
 861
 862 static gint
 863 pen_handle_2button_press(SPPenContext *const pc, GdkEventButton const &bevent)
 864 {
 865     gint ret = FALSE;
 866     // only end on LMB double click. Otherwise horizontal scrolling causes ending of the path
 867     if (pc->npoints != 0 && bevent.button == 1) {
 868         spdc_pen_finish(pc, FALSE);
 869         ret = TRUE;
 870     }
 871     return ret;
 872 }
 873
 874 void
 875 pen_redraw_all (SPPenContext *const pc)
 876 {
 877     // green
 878     if (pc->green_bpaths) {
 879         // remove old piecewise green canvasitems
 880         while (pc->green_bpaths) {
 881             gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
 882             pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
 883         }
 884         // one canvas bpath for all of green_curve
 885         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), pc->green_curve);
 886         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 887         sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cshape), 0, SP_WIND_RULE_NONZERO);
 888
 889         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
 890     }
 891
 892     if (pc->green_anchor)
 893         SP_CTRL(pc->green_anchor->ctrl)->moveto(pc->green_anchor->dp);
 894
 895     pc->red_curve->reset();
 896     pc->red_curve->moveto(pc->p[0]);
 897     pc->red_curve->curveto(pc->p[1], pc->p[2], pc->p[3]);
 898     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 899
 900     // handles
 901     if (pc->p[0] != pc->p[1]) {
 902         SP_CTRL(pc->c1)->moveto(pc->p[1]);
 903         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[0], pc->p[1]);
 904         sp_canvas_item_show (pc->c1);
 905         sp_canvas_item_show (pc->cl1);
 906     } else {
 907         sp_canvas_item_hide (pc->c1);
 908         sp_canvas_item_hide (pc->cl1);
 909     }
 910
 911     Geom::Curve const * last_seg = pc->green_curve->last_segment();
 912     if (last_seg) {
 913         Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>( last_seg );
 914         if ( cubic &&
 915              (*cubic)[2] != to_2geom(pc->p[0]) )
 916         {
 917             Geom::Point p2 = (*cubic)[2];
 918             SP_CTRL(pc->c0)->moveto(p2);
 919             sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl0), p2, pc->p[0]);
 920             sp_canvas_item_show (pc->c0);
 921             sp_canvas_item_show (pc->cl0);
 922         } else {
 923             sp_canvas_item_hide (pc->c0);
 924             sp_canvas_item_hide (pc->cl0);
 925         }
 926     }
 927 }
 928
 929 void
 930 pen_lastpoint_move (SPPenContext *const pc, gdouble x, gdouble y)
 931 {
 932     if (pc->npoints != 5)
 933         return;
 934
 935     // green
 936     if (!pc->green_curve->is_empty()) {
 937         pc->green_curve->last_point_additive_move( Geom::Point(x,y) );
 938     } else {
 939         // start anchor too
 940         if (pc->green_anchor) {
 941             pc->green_anchor->dp += Geom::Point(x, y);
 942         }
 943     }
 944
 945     // red
 946     pc->p[0] += Geom::Point(x, y);
 947     pc->p[1] += Geom::Point(x, y);
 948     pen_redraw_all(pc);
 949 }
 950
 951 void
 952 pen_lastpoint_move_screen (SPPenContext *const pc, gdouble x, gdouble y)
 953 {
 954     pen_lastpoint_move (pc, x / pc->desktop->current_zoom(), y / pc->desktop->current_zoom());
 955 }
 956
 957 void
 958 pen_lastpoint_tocurve (SPPenContext *const pc)
 959 {
 960     if (pc->npoints != 5)
 961         return;
 962
 963     Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>( pc->green_curve->last_segment() );
 964     if ( cubic ) {
 965         pc->p[1] = pc->p[0] + (Geom::Point)( (*cubic)[3] - (*cubic)[2] );
 966     } else {
 967         pc->p[1] = pc->p[0] + (1./3)*(pc->p[3] - pc->p[0]);
 968     }
 969
 970     pen_redraw_all(pc);
 971 }
 972
 973 void
 974 pen_lastpoint_toline (SPPenContext *const pc)
 975 {
 976     if (pc->npoints != 5)
 977         return;
 978
 979     pc->p[1] = pc->p[0];
 980
 981     pen_redraw_all(pc);
 982 }
 983
 984
 985 static gint
 986 pen_handle_key_press(SPPenContext *const pc, GdkEvent *event)
 987 {
 988
 989     gint ret = FALSE;
 990     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 991     gdouble const nudge = prefs->getDoubleLimited("/options/nudgedistance/value", 2, 0, 1000); // in px
 992
 993     switch (get_group0_keyval (&event->key)) {
 994
 995         case GDK_Left: // move last point left
 996         case GDK_KP_Left:
 997         case GDK_KP_4:
 998             if (!MOD__CTRL) { // not ctrl
 999                 if (MOD__ALT) { // alt
1000                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, -10, 0); // shift
1001                     else pen_lastpoint_move_screen(pc, -1, 0); // no shift
1002                 }
1003                 else { // no alt
1004                     if (MOD__SHIFT) pen_lastpoint_move(pc, -10*nudge, 0); // shift
1005                     else pen_lastpoint_move(pc, -nudge, 0); // no shift
1006                 }
1007                 ret = TRUE;
1008             }
1009             break;
1010         case GDK_Up: // move last point up
1011         case GDK_KP_Up:
1012         case GDK_KP_8:
1013             if (!MOD__CTRL) { // not ctrl
1014                 if (MOD__ALT) { // alt
1015                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 0, 10); // shift
1016                     else pen_lastpoint_move_screen(pc, 0, 1); // no shift
1017                 }
1018                 else { // no alt
1019                     if (MOD__SHIFT) pen_lastpoint_move(pc, 0, 10*nudge); // shift
1020                     else pen_lastpoint_move(pc, 0, nudge); // no shift
1021                 }
1022                 ret = TRUE;
1023             }
1024             break;
1025         case GDK_Right: // move last point right
1026         case GDK_KP_Right:
1027         case GDK_KP_6:
1028             if (!MOD__CTRL) { // not ctrl
1029                 if (MOD__ALT) { // alt
1030                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 10, 0); // shift
1031                     else pen_lastpoint_move_screen(pc, 1, 0); // no shift
1032                 }
1033                 else { // no alt
1034                     if (MOD__SHIFT) pen_lastpoint_move(pc, 10*nudge, 0); // shift
1035                     else pen_lastpoint_move(pc, nudge, 0); // no shift
1036                 }
1037                 ret = TRUE;
1038             }
1039             break;
1040         case GDK_Down: // move last point down
1041         case GDK_KP_Down:
1042         case GDK_KP_2:
1043             if (!MOD__CTRL) { // not ctrl
1044                 if (MOD__ALT) { // alt
1045                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 0, -10); // shift
1046                     else pen_lastpoint_move_screen(pc, 0, -1); // no shift
1047                 }
1048                 else { // no alt
1049                     if (MOD__SHIFT) pen_lastpoint_move(pc, 0, -10*nudge); // shift
1050                     else pen_lastpoint_move(pc, 0, -nudge); // no shift
1051                 }
1052                 ret = TRUE;
1053             }
1054             break;
1055
1056 /* TODO: this is not yet enabled?? looks like some traces of the Geometry tool
1057         case GDK_P:
1058         case GDK_p:
1059             if (MOD__SHIFT_ONLY) {
1060                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::PARALLEL, 2);
1061                 ret = TRUE;
1062             }
1063             break;
1064
1065         case GDK_C:
1066         case GDK_c:
1067             if (MOD__SHIFT_ONLY) {
1068                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::CIRCLE_3PTS, 3);
1069                 ret = TRUE;
1070             }
1071             break;
1072
1073         case GDK_B:
1074         case GDK_b:
1075             if (MOD__SHIFT_ONLY) {
1076                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::PERP_BISECTOR, 2);
1077                 ret = TRUE;
1078             }
1079             break;
1080
1081         case GDK_A:
1082         case GDK_a:
1083             if (MOD__SHIFT_ONLY) {
1084                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::ANGLE_BISECTOR, 3);
1085                 ret = TRUE;
1086             }
1087             break;
1088 */
1089
1090         case GDK_U:
1091         case GDK_u:
1092             if (MOD__SHIFT_ONLY) {
1093                 pen_lastpoint_tocurve(pc);
1094                 ret = TRUE;
1095             }
1096             break;
1097         case GDK_L:
1098         case GDK_l:
1099             if (MOD__SHIFT_ONLY) {
1100                 pen_lastpoint_toline(pc);
1101                 ret = TRUE;
1102             }
1103             break;
1104
1105         case GDK_Return:
1106         case GDK_KP_Enter:
1107             if (pc->npoints != 0) {
1108                 spdc_pen_finish(pc, FALSE);
1109                 ret = TRUE;
1110             }
1111             break;
1112         case GDK_Escape:
1113             if (pc->npoints != 0) {
1114                 // if drawing, cancel, otherwise pass it up for deselecting
1115                 pen_cancel (pc);
1116                 ret = TRUE;
1117             }
1118             break;
1119         case GDK_z:
1120         case GDK_Z:
1121             if (MOD__CTRL_ONLY && pc->npoints != 0) {
1122                 // if drawing, cancel, otherwise pass it up for undo
1123                 pen_cancel (pc);
1124                 ret = TRUE;
1125             }
1126             break;
1127         case GDK_g:
1128         case GDK_G:
1129             if (MOD__SHIFT_ONLY) {
1130                 sp_selection_to_guides(SP_EVENT_CONTEXT(pc)->desktop);
1131                 ret = true;
1132             }
1133             break;
1134         case GDK_BackSpace:
1135         case GDK_Delete:
1136         case GDK_KP_Delete:
1137             if ( pc->green_curve->is_empty() || (pc->green_curve->last_segment() == NULL) ) {
1138                 if (!pc->red_curve->is_empty()) {
1139                     pen_cancel (pc);
1140                     ret = TRUE;
1141                 } else {
1142                     // do nothing; this event should be handled upstream
1143                 }
1144             } else {
1145                 /* Reset red curve */
1146                 pc->red_curve->reset();
1147                 /* Destroy topmost green bpath */
1148                 if (pc->green_bpaths) {
1149                     if (pc->green_bpaths->data)
1150                         gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
1151                     pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
1152                 }
1153                 /* Get last segment */
1154                 if ( pc->green_curve->is_empty() ) {
1155                     g_warning("pen_handle_key_press, case GDK_KP_Delete: Green curve is empty");
1156                     break;
1157                 }
1158                 // The code below assumes that pc->green_curve has only ONE path !
1159                 Geom::Curve const * crv = pc->green_curve->last_segment();
1160                 pc->p[0] = crv->initialPoint();
1161                 if ( Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>(crv)) {
1162                     pc->p[1] = (*cubic)[1];
1163                 } else {
1164                     pc->p[1] = pc->p[0];
1165                 }
1166                 Geom::Point const pt(( pc->npoints < 4
1167                                      ? (Geom::Point)(crv->finalPoint())
1168                                      : pc->p[3] ));
1169                 pc->npoints = 2;
1170                 pc->green_curve->backspace();
1171                 sp_canvas_item_hide(pc->c0);
1172                 sp_canvas_item_hide(pc->c1);
1173                 sp_canvas_item_hide(pc->cl0);
1174                 sp_canvas_item_hide(pc->cl1);
1175                 pc->state = SP_PEN_CONTEXT_POINT;
1176                 spdc_pen_set_subsequent_point(pc, pt, true);
1177                 pen_last_paraxial_dir = !pen_last_paraxial_dir;
1178                 ret = TRUE;
1179             }
1180             break;
1181         default:
1182             break;
1183     }
1184     return ret;
1185 }
1186
1187 static void
1188 spdc_reset_colors(SPPenContext *pc)
1189 {
1190     /* Red */
1191     pc->red_curve->reset();
1192     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
1193     /* Blue */
1194     pc->blue_curve->reset();
1195     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->blue_bpath), NULL);
1196     /* Green */
1197     while (pc->green_bpaths) {
1198         gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
1199         pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
1200     }
1201     pc->green_curve->reset();
1202     if (pc->green_anchor) {
1203         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
1204     }
1205     pc->sa = NULL;
1206     pc->ea = NULL;
1207     pc->npoints = 0;
1208     pc->red_curve_is_valid = false;
1209 }
1210
1211
1212 static void
1213 spdc_pen_set_initial_point(SPPenContext *const pc, Geom::Point const p)
1214 {
1215     g_assert( pc->npoints == 0 );
1216
1217     pc->p[0] = p;
1218     pc->p[1] = p;
1219     pc->npoints = 2;
1220     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
1221
1222     sp_canvas_force_full_redraw_after_interruptions(pc->desktop->canvas, 5);
1223 }
1224
1225 /**
1226  * Show the status message for the current line/curve segment.
1227  * This type of message always shows angle/distance as the last
1228  * two parameters ("angle %3.2f&#176;, distance %s").
1229  */
1230 static void
1231 spdc_pen_set_angle_distance_status_message(SPPenContext *const pc, Geom::Point const p, int pc_point_to_compare, gchar const *message)
1232 {
1233     g_assert(pc != NULL);
1234     g_assert((pc_point_to_compare == 0) || (pc_point_to_compare == 3)); // exclude control handles
1235     g_assert(message != NULL);
1236
1237     SPDesktop *desktop = SP_EVENT_CONTEXT(pc)->desktop;
1238     Geom::Point rel = p - pc->p[pc_point_to_compare];
1239     GString *dist = SP_PX_TO_METRIC_STRING(Geom::L2(rel), desktop->namedview->getDefaultMetric());
1240     double angle = atan2(rel[Geom::Y], rel[Geom::X]) * 180 / M_PI;
1241     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
1242     if (prefs->getBool("/options/compassangledisplay/value", 0) != 0)
1243         angle = angle_to_compass (angle);
1244
1245     pc->_message_context->setF(Inkscape::IMMEDIATE_MESSAGE, message, angle, dist->str);
1246     g_string_free(dist, FALSE);
1247 }
1248
1249 static void
1250 spdc_pen_set_subsequent_point(SPPenContext *const pc, Geom::Point const p, bool statusbar, guint status)
1251 {
1252     g_assert( pc->npoints != 0 );
1253     /* todo: Check callers to see whether 2 <= npoints is guaranteed. */
1254
1255     pc->p[2] = p;
1256     pc->p[3] = p;
1257     pc->p[4] = p;
1258     pc->npoints = 5;
1259     pc->red_curve->reset();
1260     bool is_curve;
1261     pc->red_curve->moveto(pc->p[0]);
1262     if (pc->polylines_paraxial && !statusbar) {
1263         // we are drawing horizontal/vertical lines and hit an anchor;
1264         Geom::Point const origin = pc->p[0];
1265         // if the previous point and the anchor are not aligned either horizontally or vertically...
1266         if ((abs(p[Geom::X] - origin[Geom::X]) > 1e-9) && (abs(p[Geom::Y] - origin[Geom::Y]) > 1e-9)) {
1267             // ...then we should draw an L-shaped path, consisting of two paraxial segments
1268             Geom::Point intermed = p;
1269             pen_set_to_nearest_horiz_vert(pc, intermed, status, false);
1270             pc->red_curve->lineto(intermed);
1271         }
1272         pc->red_curve->lineto(p);
1273         is_curve = false;
1274     } else {
1275         // one of the 'regular' modes
1276         if (pc->p[1] != pc->p[0]) {
1277             pc->red_curve->curveto(pc->p[1], p, p);
1278             is_curve = true;
1279         } else {
1280             pc->red_curve->lineto(p);
1281             is_curve = false;
1282         }
1283     }
1284
1285     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
1286
1287     if (statusbar) {
1288         gchar *message = is_curve ?
1289             _("<b>Curve segment</b>: angle %3.2f&#176;, distance %s; with <b>Ctrl</b> to snap angle, <b>Enter</b> to finish the path" ):
1290             _("<b>Line segment</b>: angle %3.2f&#176;, distance %s; with <b>Ctrl</b> to snap angle, <b>Enter</b> to finish the path");
1291         spdc_pen_set_angle_distance_status_message(pc, p, 0, message);
1292     }
1293 }
1294
1295 static void
1296 spdc_pen_set_ctrl(SPPenContext *const pc, Geom::Point const p, guint const state)
1297 {
1298     sp_canvas_item_show(pc->c1);
1299     sp_canvas_item_show(pc->cl1);
1300
1301     if ( pc->npoints == 2 ) {
1302         pc->p[1] = p;
1303         sp_canvas_item_hide(pc->c0);
1304         sp_canvas_item_hide(pc->cl0);
1305         SP_CTRL(pc->c1)->moveto(pc->p[1]);
1306         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[0], pc->p[1]);
1307
1308         spdc_pen_set_angle_distance_status_message(pc, p, 0, _("<b>Curve handle</b>: angle %3.2f&#176;, length %s; with <b>Ctrl</b> to snap angle"));
1309     } else if ( pc->npoints == 5 ) {
1310         pc->p[4] = p;
1311         sp_canvas_item_show(pc->c0);
1312         sp_canvas_item_show(pc->cl0);
1313         bool is_symm = false;
1314         if ( ( ( pc->mode == SP_PEN_CONTEXT_MODE_CLICK ) && ( state & GDK_CONTROL_MASK ) ) ||
1315              ( ( pc->mode == SP_PEN_CONTEXT_MODE_DRAG ) &&  !( state & GDK_SHIFT_MASK  ) ) ) {
1316             Geom::Point delta = p - pc->p[3];
1317             pc->p[2] = pc->p[3] - delta;
1318             is_symm = true;
1319             pc->red_curve->reset();
1320             pc->red_curve->moveto(pc->p[0]);
1321             pc->red_curve->curveto(pc->p[1], pc->p[2], pc->p[3]);
1322             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
1323         }
1324         SP_CTRL(pc->c0)->moveto(pc->p[2]);
1325         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl0), pc->p[3], pc->p[2]);
1326         SP_CTRL(pc->c1)->moveto(pc->p[4]);
1327         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[3], pc->p[4]);
1328
1329         gchar *message = is_symm ?
1330             _("<b>Curve handle, symmetric</b>: angle %3.2f&#176;, length %s; with <b>Ctrl</b> to snap angle, with <b>Shift</b> to move this handle only") :
1331             _("<b>Curve handle</b>: angle %3.2f&#176;, length %s; with <b>Ctrl</b> to snap angle, with <b>Shift</b> to move this handle only");
1332         spdc_pen_set_angle_distance_status_message(pc, p, 3, message);
1333     } else {
1334         g_warning("Something bad happened - npoints is %d", pc->npoints);
1335     }
1336 }
1337
1338 static void
1339 spdc_pen_finish_segment(SPPenContext *const pc, Geom::Point const p, guint const state)
1340 {
1341     if (pc->polylines_paraxial) {
1342         pen_last_paraxial_dir = pen_next_paraxial_direction(pc, p, pc->p[0], state);
1343     }
1344
1345     ++pc->num_clicks;
1346
1347     if (!pc->red_curve->is_empty()) {
1348         pc->green_curve->append_continuous(pc->red_curve, 0.0625);
1349         SPCurve *curve = pc->red_curve->copy();
1350         /// \todo fixme:
1351         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), curve);
1352         curve->unref();
1353         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
1354
1355         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
1356
1357         pc->p[0] = pc->p[3];
1358         pc->p[1] = pc->p[4];
1359         pc->npoints = 2;
1360
1361         pc->red_curve->reset();
1362     }
1363 }
1364
1365 static void
1366 spdc_pen_finish(SPPenContext *const pc, gboolean const closed)
1367 {
1368     if (pc->expecting_clicks_for_LPE > 1) {
1369         // don't let the path be finished before we have collected the required number of mouse clicks
1370         return;
1371     }
1372
1373     pc->num_clicks = 0;
1374
1375     pen_disable_events(pc);
1376
1377     SPDesktop *const desktop = pc->desktop;
1378     pc->_message_context->clear();
1379     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Drawing finished"));
1380
1381     pc->red_curve->reset();
1382     spdc_concat_colors_and_flush(pc, closed);
1383     pc->sa = NULL;
1384     pc->ea = NULL;
1385
1386     pc->npoints = 0;
1387     pc->state = SP_PEN_CONTEXT_POINT;
1388
1389     sp_canvas_item_hide(pc->c0);
1390     sp_canvas_item_hide(pc->c1);
1391     sp_canvas_item_hide(pc->cl0);
1392     sp_canvas_item_hide(pc->cl1);
1393
1394     if (pc->green_anchor) {
1395         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
1396     }
1397
1398
1399     sp_canvas_end_forced_full_redraws(pc->desktop->canvas);
1400
1401     pen_enable_events(pc);
1402 }
1403
1404 static void
1405 pen_disable_events(SPPenContext *const pc) {
1406   pc->events_disabled++;
1407 }
1408
1409 static void
1410 pen_enable_events(SPPenContext *const pc) {
1411   g_return_if_fail(pc->events_disabled != 0);
1412
1413   pc->events_disabled--;
1414 }
1415
1416 void
1417 sp_pen_context_wait_for_LPE_mouse_clicks(SPPenContext *pc, Inkscape::LivePathEffect::EffectType effect_type,
1418                                          unsigned int num_clicks, bool use_polylines)
1419 {
1420     if (effect_type == Inkscape::LivePathEffect::INVALID_LPE)
1421         return;
1422
1423     pc->waiting_LPE_type = effect_type;
1424     pc->expecting_clicks_for_LPE = num_clicks;
1425     pc->polylines_only = use_polylines;
1426     pc->polylines_paraxial = false; // TODO: think if this is correct for all cases
1427 }
1428
1429 void
1430 sp_pen_context_cancel_waiting_for_LPE(SPPenContext *pc)
1431 {
1432     pc->waiting_LPE_type = Inkscape::LivePathEffect::INVALID_LPE;
1433     pc->expecting_clicks_for_LPE = 0;
1434     sp_pen_context_set_polyline_mode(pc);
1435 }
1436
1437 static int pen_next_paraxial_direction(const SPPenContext *const pc,
1438                                        Geom::Point const &pt, Geom::Point const &origin, guint state) {
1439     /*
1440      * after the first mouse click we determine whether the mouse pointer is closest to a
1441      * horizontal or vertical segment; for all subsequent mouse clicks, we use the direction
1442      * orthogonal to the last one; pressing Shift toggles the direction
1443      */
1444     // num_clicks is not reliable because spdc_pen_finish_segment is sometimes called too early
1445     // (on first mouse release), in which case num_clicks immediately becomes 1.
1446     // if (pc->num_clicks == 0) {
1447
1448     if (pc->green_curve->is_empty()) {
1449         // first mouse click
1450         double dist_h = fabs(pt[Geom::X] - origin[Geom::X]);
1451         double dist_v = fabs(pt[Geom::Y] - origin[Geom::Y]);
1452         int ret = (dist_h < dist_v) ? 1 : 0; // 0 = horizontal, 1 = vertical
1453         pen_last_paraxial_dir = (state & GDK_SHIFT_MASK) ? 1 - ret : ret;
1454         return pen_last_paraxial_dir;
1455     } else {
1456         // subsequent mouse click
1457         return (state & GDK_SHIFT_MASK) ? pen_last_paraxial_dir : 1 - pen_last_paraxial_dir;
1458     }
1459 }
1460
1461 void pen_set_to_nearest_horiz_vert(const SPPenContext *const pc, Geom::Point &pt, guint const state, bool snap)
1462 {
1463     Geom::Point const origin = pc->p[0];
1464
1465     int next_dir = pen_next_paraxial_direction(pc, pt, origin, state);
1466
1467     if (!snap) {
1468         if (next_dir == 0) {
1469             // line is forced to be horizontal
1470             pt[Geom::Y] = origin[Geom::Y];
1471         } else {
1472             // line is forced to be vertical
1473             pt[Geom::X] = origin[Geom::X];
1474         }
1475     } else {
1476         // Create a horizontal or vertical constraint line
1477         Inkscape::Snapper::SnapConstraint cl(origin, next_dir ? Geom::Point(0, 1) : Geom::Point(1, 0));
1478
1479         // Snap along the constraint line; if we didn't snap then still the constraint will be applied
1480         SnapManager &m = pc->desktop->namedview->snap_manager;
1481
1482         Inkscape::Selection *selection = sp_desktop_selection (pc->desktop);
1483         // selection->singleItem() is the item that is currently being drawn. This item will not be snapped to (to avoid self-snapping)
1484         // TODO: Allow snapping to the stationary parts of the item, and only ignore the last segment
1485
1486         m.setup(pc->desktop, true, selection->singleItem());
1487         m.constrainedSnapReturnByRef(pt, Inkscape::SNAPSOURCE_NODE_HANDLE, cl);
1488         m.unSetup();
1489     }
1490 }
1491
1492 /*
1493   Local Variables:
1494   mode:c++
1495   c-file-style:"stroustrup"
1496   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1497   indent-tabs-mode:nil
1498   fill-column:99
1499   End:
1500 */
1501 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :