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);
  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     sp_canvas_set_snap_delay_active(pc->desktop->canvas, true);
 212
 213     if (((SPEventContextClass *) pen_parent_class)->setup) {
 214         ((SPEventContextClass *) pen_parent_class)->setup(ec);
 215     }
 216
 217     /* Pen indicators */
 218     pc->c0 = 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->c1 = sp_canvas_item_new(sp_desktop_controls(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRL, "shape", SP_CTRL_SHAPE_CIRCLE,
 221                                 "size", 4.0, "filled", 0, "fill_color", 0xff00007f, "stroked", 1, "stroke_color", 0x0000ff7f, NULL);
 222     pc->cl0 = sp_canvas_item_new(sp_desktop_controls(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRLLINE, NULL);
 223     sp_ctrlline_set_rgba32(SP_CTRLLINE(pc->cl0), 0x0000007f);
 224     pc->cl1 = sp_canvas_item_new(sp_desktop_controls(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRLLINE, NULL);
 225     sp_ctrlline_set_rgba32(SP_CTRLLINE(pc->cl1), 0x0000007f);
 226
 227     sp_canvas_item_hide(pc->c0);
 228     sp_canvas_item_hide(pc->c1);
 229     sp_canvas_item_hide(pc->cl0);
 230     sp_canvas_item_hide(pc->cl1);
 231
 232     sp_event_context_read(ec, "mode");
 233
 234     pc->anchor_statusbar = false;
 235
 236     sp_pen_context_set_polyline_mode(pc);
 237
 238     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 239     if (prefs->getBool("/tools/freehand/pen/selcue")) {
 240         ec->enableSelectionCue();
 241     }
 242 }
 243
 244 static void
 245 pen_cancel (SPPenContext *const pc)
 246 {
 247     pc->num_clicks = 0;
 248     pc->state = SP_PEN_CONTEXT_STOP;
 249     spdc_reset_colors(pc);
 250     sp_canvas_item_hide(pc->c0);
 251     sp_canvas_item_hide(pc->c1);
 252     sp_canvas_item_hide(pc->cl0);
 253     sp_canvas_item_hide(pc->cl1);
 254     pc->_message_context->clear();
 255     pc->_message_context->flash(Inkscape::NORMAL_MESSAGE, _("Drawing cancelled"));
 256
 257     sp_canvas_end_forced_full_redraws(pc->desktop->canvas);
 258 }
 259
 260 /**
 261  * Finalization callback.
 262  */
 263 static void
 264 sp_pen_context_finish(SPEventContext *ec)
 265 {
 266     SPPenContext *pc = SP_PEN_CONTEXT(ec);
 267
 268     sp_canvas_set_snap_delay_active(pc->desktop->canvas, false);
 269
 270     if (pc->npoints != 0) {
 271         pen_cancel (pc);
 272     }
 273
 274     if (((SPEventContextClass *) pen_parent_class)->finish) {
 275         ((SPEventContextClass *) pen_parent_class)->finish(ec);
 276     }
 277 }
 278
 279 /**
 280  * Callback that sets key to value in pen context.
 281  */
 282 static void
 283 sp_pen_context_set(SPEventContext *ec, Inkscape::Preferences::Entry *val)
 284 {
 285     SPPenContext *pc = SP_PEN_CONTEXT(ec);
 286     Glib::ustring name = val->getEntryName();
 287
 288     if (name == "mode") {
 289         if ( val->getString() == "drag" ) {
 290             pc->mode = SP_PEN_CONTEXT_MODE_DRAG;
 291         } else {
 292             pc->mode = SP_PEN_CONTEXT_MODE_CLICK;
 293         }
 294     }
 295 }
 296
 297 /**
 298  * Snaps new node relative to the previous node.
 299  */
 300 static void
 301 spdc_endpoint_snap(SPPenContext const *const pc, Geom::Point &p, guint const state)
 302 {
 303     if ((state & GDK_CONTROL_MASK)) { //CTRL enables angular snapping
 304         if (pc->npoints > 0) {
 305             spdc_endpoint_snap_rotation(pc, p, pc->p[0], state);
 306         }
 307     } else {
 308         if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above
 309                                          //After all, the user explicitely asked for angular snapping by
 310                                          //pressing CTRL
 311             spdc_endpoint_snap_free(pc, p, state);
 312         }
 313     }
 314     if (pc->polylines_paraxial) {
 315         // TODO: must we avoid one of the snaps in the previous case distinction in some situations?
 316         pen_set_to_nearest_horiz_vert(pc, p, state);
 317     }
 318 }
 319
 320 /**
 321  * Snaps new node's handle relative to the new node.
 322  */
 323 static void
 324 spdc_endpoint_snap_handle(SPPenContext const *const pc, Geom::Point &p, guint const state)
 325 {
 326     g_return_if_fail(( pc->npoints == 2 ||
 327                        pc->npoints == 5   ));
 328
 329     if ((state & GDK_CONTROL_MASK)) { //CTRL enables angular snapping
 330         spdc_endpoint_snap_rotation(pc, p, pc->p[pc->npoints - 2], state);
 331     } else {
 332         if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above
 333             spdc_endpoint_snap_free(pc, p, state);
 334         }
 335     }
 336 }
 337
 338 static gint
 339 sp_pen_context_item_handler(SPEventContext *ec, SPItem *item, GdkEvent *event)
 340 {
 341     SPPenContext *const pc = SP_PEN_CONTEXT(ec);
 342
 343     gint ret = FALSE;
 344
 345     switch (event->type) {
 346         case GDK_BUTTON_PRESS:
 347             ret = pen_handle_button_press(pc, event->button);
 348             break;
 349         case GDK_BUTTON_RELEASE:
 350             ret = pen_handle_button_release(pc, event->button);
 351             break;
 352         default:
 353             break;
 354     }
 355
 356     if (!ret) {
 357         if (((SPEventContextClass *) pen_parent_class)->item_handler)
 358             ret = ((SPEventContextClass *) pen_parent_class)->item_handler(ec, item, event);
 359     }
 360
 361     return ret;
 362 }
 363
 364 /**
 365  * Callback to handle all pen events.
 366  */
 367 static gint
 368 sp_pen_context_root_handler(SPEventContext *ec, GdkEvent *event)
 369 {
 370     SPPenContext *const pc = SP_PEN_CONTEXT(ec);
 371
 372     gint ret = FALSE;
 373
 374     switch (event->type) {
 375         case GDK_BUTTON_PRESS:
 376             ret = pen_handle_button_press(pc, event->button);
 377             break;
 378
 379         case GDK_MOTION_NOTIFY:
 380             ret = pen_handle_motion_notify(pc, event->motion);
 381             break;
 382
 383         case GDK_BUTTON_RELEASE:
 384             ret = pen_handle_button_release(pc, event->button);
 385             break;
 386
 387         case GDK_2BUTTON_PRESS:
 388             ret = pen_handle_2button_press(pc, event->button);
 389             break;
 390
 391         case GDK_KEY_PRESS:
 392             ret = pen_handle_key_press(pc, event);
 393             break;
 394
 395         default:
 396             break;
 397     }
 398
 399     if (!ret) {
 400         gint (*const parent_root_handler)(SPEventContext *, GdkEvent *)
 401             = ((SPEventContextClass *) pen_parent_class)->root_handler;
 402         if (parent_root_handler) {
 403             ret = parent_root_handler(ec, event);
 404         }
 405     }
 406
 407     return ret;
 408 }
 409
 410 /**
 411  * Handle mouse button press event.
 412  */
 413 static gint pen_handle_button_press(SPPenContext *const pc, GdkEventButton const &bevent)
 414 {
 415     if (pc->events_disabled) {
 416         // skip event processing if events are disabled
 417         return FALSE;
 418     }
 419
 420     SPDrawContext * const dc = SP_DRAW_CONTEXT(pc);
 421     SPDesktop * const desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 422     Geom::Point const event_w(bevent.x, bevent.y);
 423     Geom::Point event_dt(desktop->w2d(event_w));
 424     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 425
 426     gint ret = FALSE;
 427     if (bevent.button == 1 && !event_context->space_panning
 428         // make sure this is not the last click for a waiting LPE (otherwise we want to finish the path)
 429         && pc->expecting_clicks_for_LPE != 1) {
 430
 431         if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 432             return TRUE;
 433         }
 434
 435         if (!pc->grab ) {
 436             /* Grab mouse, so release will not pass unnoticed */
 437             pc->grab = SP_CANVAS_ITEM(desktop->acetate);
 438             sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK   |
 439                                             GDK_BUTTON_RELEASE_MASK |
 440                                             GDK_POINTER_MOTION_MASK  ),
 441                                 NULL, bevent.time);
 442         }
 443
 444         pen_drag_origin_w = event_w;
 445         pen_within_tolerance = true;
 446
 447         /* Test whether we hit any anchor. */
 448         SPDrawAnchor * const anchor = spdc_test_inside(pc, event_w);
 449
 450         switch (pc->mode) {
 451             case SP_PEN_CONTEXT_MODE_CLICK:
 452                 /* In click mode we add point on release */
 453                 switch (pc->state) {
 454                     case SP_PEN_CONTEXT_POINT:
 455                     case SP_PEN_CONTEXT_CONTROL:
 456                     case SP_PEN_CONTEXT_CLOSE:
 457                         break;
 458                     case SP_PEN_CONTEXT_STOP:
 459                         /* This is allowed, if we just canceled curve */
 460                         pc->state = SP_PEN_CONTEXT_POINT;
 461                         break;
 462                     default:
 463                         break;
 464                 }
 465                 break;
 466             case SP_PEN_CONTEXT_MODE_DRAG:
 467                 switch (pc->state) {
 468                     case SP_PEN_CONTEXT_STOP:
 469                         /* This is allowed, if we just canceled curve */
 470                     case SP_PEN_CONTEXT_POINT:
 471                         if (pc->npoints == 0) {
 472
 473                                 Geom::Point p;
 474                           if ((bevent.state & GDK_CONTROL_MASK) && (pc->polylines_only || pc->polylines_paraxial)) {
 475                                 p = event_dt;
 476                                 if (!(bevent.state & GDK_SHIFT_MASK)) {
 477                                         SnapManager &m = desktop->namedview->snap_manager;
 478                                         m.setup(desktop);
 479                                                                         m.freeSnapReturnByRef(Inkscape::SnapPreferences::SNAPPOINT_NODE, p, Inkscape::SNAPSOURCE_HANDLE);
 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                                 if (!pc->polylines_paraxial) {
 513                                     // only snap the starting point if we're not in horizontal/vertical mode
 514                                     // because otherwise it gets shifted; TODO: why do we snap here at all??
 515                                     spdc_endpoint_snap(pc, p, bevent.state);
 516                                 }
 517                                 pc->green_anchor = sp_draw_anchor_new(pc, pc->green_curve, TRUE, p);
 518                             }
 519                             spdc_pen_set_initial_point(pc, p);
 520                         } else {
 521
 522                             /* Set end anchor */
 523                             pc->ea = anchor;
 524                             Geom::Point p;
 525                             if (anchor) {
 526                                 p = anchor->dp;
 527                                 // we hit an anchor, will finish the curve (either with or without closing)
 528                                 // in release handler
 529                                 pc->state = SP_PEN_CONTEXT_CLOSE;
 530
 531                                 if (pc->green_anchor && pc->green_anchor->active) {
 532                                     // we clicked on the current curve start, so close it even if
 533                                     // we drag a handle away from it
 534                                     dc->green_closed = TRUE;
 535                                 }
 536                                 ret = TRUE;
 537                                 break;
 538
 539                             } else {
 540                                 p = event_dt;
 541                                 spdc_endpoint_snap(pc, p, bevent.state); /* Snap node only if not hitting anchor. */
 542                                 spdc_pen_set_subsequent_point(pc, p, true);
 543                                 if (pc->polylines_only) {
 544                                     spdc_pen_finish_segment(pc, p, bevent.state);
 545                                 }
 546                             }
 547                         }
 548
 549                         pc->state = pc->polylines_only ? SP_PEN_CONTEXT_POINT : SP_PEN_CONTEXT_CONTROL;
 550                         ret = TRUE;
 551                         break;
 552                     case SP_PEN_CONTEXT_CONTROL:
 553                         g_warning("Button down in CONTROL state");
 554                         break;
 555                     case SP_PEN_CONTEXT_CLOSE:
 556                         g_warning("Button down in CLOSE state");
 557                         break;
 558                     default:
 559                         break;
 560                 }
 561                 break;
 562             default:
 563                 break;
 564         }
 565     } else if (bevent.button == 3 || pc->expecting_clicks_for_LPE == 1) { // when the last click for a waiting LPE occurs we want to finish the path
 566         if (pc->npoints != 0) {
 567
 568             spdc_pen_finish_segment(pc, event_dt, bevent.state);
 569             if (pc->green_closed) {
 570                 // finishing at the start anchor, close curve
 571                 spdc_pen_finish(pc, TRUE);
 572             } else {
 573                 // finishing at some other anchor, finish curve but not close
 574                 spdc_pen_finish(pc, FALSE);
 575             }
 576
 577             ret = TRUE;
 578         }
 579     }
 580
 581     if (pc->expecting_clicks_for_LPE > 0) {
 582         --pc->expecting_clicks_for_LPE;
 583     }
 584
 585     return ret;
 586 }
 587
 588 /**
 589  * Handle motion_notify event.
 590  */
 591 static gint
 592 pen_handle_motion_notify(SPPenContext *const pc, GdkEventMotion const &mevent)
 593 {
 594     gint ret = FALSE;
 595
 596     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 597     SPDesktop * const dt = SP_EVENT_CONTEXT_DESKTOP(event_context);
 598
 599     if (event_context->space_panning || mevent.state & GDK_BUTTON2_MASK || mevent.state & GDK_BUTTON3_MASK) {
 600         // allow scrolling
 601         return FALSE;
 602     }
 603
 604     if (pc->events_disabled) {
 605         // skip motion events if pen events are disabled
 606         return FALSE;
 607     }
 608
 609     Geom::Point const event_w(mevent.x,
 610                             mevent.y);
 611     if (pen_within_tolerance) {
 612         Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 613         gint const tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
 614         if ( Geom::LInfty( event_w - pen_drag_origin_w ) < tolerance ) {
 615             return FALSE;   // Do not drag if we're within tolerance from origin.
 616         }
 617     }
 618     // Once the user has moved farther than tolerance from the original location
 619     // (indicating they intend to move the object, not click), then always process the
 620     // motion notify coordinates as given (no snapping back to origin)
 621     pen_within_tolerance = false;
 622
 623     /* Find desktop coordinates */
 624     Geom::Point p = dt->w2d(event_w);
 625
 626     /* Test, whether we hit any anchor */
 627     SPDrawAnchor *anchor = spdc_test_inside(pc, event_w);
 628
 629     switch (pc->mode) {
 630         case SP_PEN_CONTEXT_MODE_CLICK:
 631             switch (pc->state) {
 632                 case SP_PEN_CONTEXT_POINT:
 633                     if ( pc->npoints != 0 ) {
 634                         /* Only set point, if we are already appending */
 635                         spdc_endpoint_snap(pc, p, mevent.state);
 636                         spdc_pen_set_subsequent_point(pc, p, true);
 637                         ret = TRUE;
 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                         }
 663
 664                         spdc_pen_set_subsequent_point(pc, p, !anchor, mevent.state);
 665
 666                         if (anchor && !pc->anchor_statusbar) {
 667                             pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to close and finish the path."));
 668                             pc->anchor_statusbar = true;
 669                         } else if (!anchor && pc->anchor_statusbar) {
 670                             pc->_message_context->clear();
 671                             pc->anchor_statusbar = false;
 672                         }
 673
 674                         ret = TRUE;
 675                     } else {
 676                         if (anchor && !pc->anchor_statusbar) {
 677                             pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to continue the path from this point."));
 678                             pc->anchor_statusbar = true;
 679                         } else if (!anchor && pc->anchor_statusbar) {
 680                             pc->_message_context->clear();
 681                             pc->anchor_statusbar = false;
 682                         }
 683                     }
 684                     break;
 685                 case SP_PEN_CONTEXT_CONTROL:
 686                 case SP_PEN_CONTEXT_CLOSE:
 687                     /* Placing controls is last operation in CLOSE state */
 688
 689                     // snap the handle
 690                     spdc_endpoint_snap_handle(pc, p, mevent.state);
 691
 692                     if (!pc->polylines_only) {
 693                         spdc_pen_set_ctrl(pc, p, mevent.state);
 694                     } else {
 695                         spdc_pen_set_ctrl(pc, pc->p[1], mevent.state);
 696                     }
 697                     gobble_motion_events(GDK_BUTTON1_MASK);
 698                     ret = TRUE;
 699                     break;
 700                 case SP_PEN_CONTEXT_STOP:
 701                     /* This is perfectly valid */
 702                     break;
 703                 default:
 704                     break;
 705             }
 706             break;
 707         default:
 708             break;
 709     }
 710     return ret;
 711 }
 712
 713 /**
 714  * Handle mouse button release event.
 715  */
 716 static gint
 717 pen_handle_button_release(SPPenContext *const pc, GdkEventButton const &revent)
 718 {
 719     if (pc->events_disabled) {
 720         // skip event processing if events are disabled
 721         return FALSE;
 722     }
 723
 724     gint ret = FALSE;
 725     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 726     if ( revent.button == 1  && !event_context->space_panning) {
 727
 728         SPDrawContext *dc = SP_DRAW_CONTEXT (pc);
 729
 730         Geom::Point const event_w(revent.x,
 731                                 revent.y);
 732         /* Find desktop coordinates */
 733         Geom::Point p = pc->desktop->w2d(event_w);
 734
 735         /* Test whether we hit any anchor. */
 736         SPDrawAnchor *anchor = spdc_test_inside(pc, event_w);
 737
 738         switch (pc->mode) {
 739             case SP_PEN_CONTEXT_MODE_CLICK:
 740                 switch (pc->state) {
 741                     case SP_PEN_CONTEXT_POINT:
 742                         if ( pc->npoints == 0 ) {
 743                             /* Start new thread only with button release */
 744                             if (anchor) {
 745                                 p = anchor->dp;
 746                             }
 747                             pc->sa = anchor;
 748                             spdc_pen_set_initial_point(pc, p);
 749                         } else {
 750                             /* Set end anchor here */
 751                             pc->ea = anchor;
 752                             if (anchor) {
 753                                 p = anchor->dp;
 754                             }
 755                         }
 756                         pc->state = SP_PEN_CONTEXT_CONTROL;
 757                         ret = TRUE;
 758                         break;
 759                     case SP_PEN_CONTEXT_CONTROL:
 760                         /* End current segment */
 761                         spdc_endpoint_snap(pc, p, revent.state);
 762                         spdc_pen_finish_segment(pc, p, revent.state);
 763                         pc->state = SP_PEN_CONTEXT_POINT;
 764                         ret = TRUE;
 765                         break;
 766                     case SP_PEN_CONTEXT_CLOSE:
 767                         /* End current segment */
 768                         if (!anchor) {   /* Snap node only if not hitting anchor */
 769                             spdc_endpoint_snap(pc, p, revent.state);
 770                         }
 771                         spdc_pen_finish_segment(pc, p, revent.state);
 772                         spdc_pen_finish(pc, TRUE);
 773                         pc->state = SP_PEN_CONTEXT_POINT;
 774                         ret = TRUE;
 775                         break;
 776                     case SP_PEN_CONTEXT_STOP:
 777                         /* This is allowed, if we just canceled curve */
 778                         pc->state = SP_PEN_CONTEXT_POINT;
 779                         ret = TRUE;
 780                         break;
 781                     default:
 782                         break;
 783                 }
 784                 break;
 785             case SP_PEN_CONTEXT_MODE_DRAG:
 786                 switch (pc->state) {
 787                     case SP_PEN_CONTEXT_POINT:
 788                     case SP_PEN_CONTEXT_CONTROL:
 789                         if (!pc->polylines_only) {
 790                             spdc_endpoint_snap(pc, p, revent.state);
 791                             spdc_pen_finish_segment(pc, p, revent.state);
 792                         }
 793                         break;
 794                     case SP_PEN_CONTEXT_CLOSE:
 795                         spdc_endpoint_snap(pc, p, revent.state);
 796                         spdc_pen_finish_segment(pc, p, revent.state);
 797                         if (pc->green_closed) {
 798                             // finishing at the start anchor, close curve
 799                             spdc_pen_finish(pc, TRUE);
 800                         } else {
 801                             // finishing at some other anchor, finish curve but not close
 802                             spdc_pen_finish(pc, FALSE);
 803                         }
 804                         break;
 805                     case SP_PEN_CONTEXT_STOP:
 806                         /* This is allowed, if we just cancelled curve */
 807                         break;
 808                     default:
 809                         break;
 810                 }
 811                 pc->state = SP_PEN_CONTEXT_POINT;
 812                 ret = TRUE;
 813                 break;
 814             default:
 815                 break;
 816         }
 817
 818         if (pc->grab) {
 819             /* Release grab now */
 820             sp_canvas_item_ungrab(pc->grab, revent.time);
 821             pc->grab = NULL;
 822         }
 823
 824         ret = TRUE;
 825
 826         dc->green_closed = FALSE;
 827     }
 828
 829     // TODO: can we be sure that the path was created correctly?
 830     // TODO: should we offer an option to collect the clicks in a list?
 831     if (pc->expecting_clicks_for_LPE == 0 && sp_pen_context_has_waiting_LPE(pc)) {
 832         sp_pen_context_set_polyline_mode(pc);
 833
 834         SPEventContext *ec = SP_EVENT_CONTEXT(pc);
 835         Inkscape::Selection *selection = sp_desktop_selection (ec->desktop);
 836
 837         if (pc->waiting_LPE) {
 838             // we have an already created LPE waiting for a path
 839             pc->waiting_LPE->acceptParamPath(SP_PATH(selection->singleItem()));
 840             selection->add(SP_OBJECT(pc->waiting_item));
 841             pc->waiting_LPE = NULL;
 842         } else {
 843             // the case that we need to create a new LPE and apply it to the just-drawn path is
 844             // handled in spdc_check_for_and_apply_waiting_LPE() in draw-context.cpp
 845         }
 846     }
 847
 848     return ret;
 849 }
 850
 851 static gint
 852 pen_handle_2button_press(SPPenContext *const pc, GdkEventButton const &bevent)
 853 {
 854     gint ret = FALSE;
 855     if (pc->npoints != 0 && bevent.button != 2) {
 856         spdc_pen_finish(pc, FALSE);
 857         ret = TRUE;
 858     }
 859     return ret;
 860 }
 861
 862 void
 863 pen_redraw_all (SPPenContext *const pc)
 864 {
 865     // green
 866     if (pc->green_bpaths) {
 867         // remove old piecewise green canvasitems
 868         while (pc->green_bpaths) {
 869             gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
 870             pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
 871         }
 872         // one canvas bpath for all of green_curve
 873         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), pc->green_curve);
 874         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 875         sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cshape), 0, SP_WIND_RULE_NONZERO);
 876
 877         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
 878     }
 879
 880     if (pc->green_anchor)
 881         SP_CTRL(pc->green_anchor->ctrl)->moveto(pc->green_anchor->dp);
 882
 883     pc->red_curve->reset();
 884     pc->red_curve->moveto(pc->p[0]);
 885     pc->red_curve->curveto(pc->p[1], pc->p[2], pc->p[3]);
 886     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 887
 888     // handles
 889     if (pc->p[0] != pc->p[1]) {
 890         SP_CTRL(pc->c1)->moveto(pc->p[1]);
 891         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[0], pc->p[1]);
 892         sp_canvas_item_show (pc->c1);
 893         sp_canvas_item_show (pc->cl1);
 894     } else {
 895         sp_canvas_item_hide (pc->c1);
 896         sp_canvas_item_hide (pc->cl1);
 897     }
 898
 899     Geom::Curve const * last_seg = pc->green_curve->last_segment();
 900     if (last_seg) {
 901         Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>( last_seg );
 902         if ( cubic &&
 903              (*cubic)[2] != to_2geom(pc->p[0]) )
 904         {
 905             Geom::Point p2 = (*cubic)[2];
 906             SP_CTRL(pc->c0)->moveto(p2);
 907             sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl0), p2, pc->p[0]);
 908             sp_canvas_item_show (pc->c0);
 909             sp_canvas_item_show (pc->cl0);
 910         } else {
 911             sp_canvas_item_hide (pc->c0);
 912             sp_canvas_item_hide (pc->cl0);
 913         }
 914     }
 915 }
 916
 917 void
 918 pen_lastpoint_move (SPPenContext *const pc, gdouble x, gdouble y)
 919 {
 920     if (pc->npoints != 5)
 921         return;
 922
 923     // green
 924     if (!pc->green_curve->is_empty()) {
 925         pc->green_curve->last_point_additive_move( Geom::Point(x,y) );
 926     } else {
 927         // start anchor too
 928         if (pc->green_anchor) {
 929             pc->green_anchor->dp += Geom::Point(x, y);
 930         }
 931     }
 932
 933     // red
 934     pc->p[0] += Geom::Point(x, y);
 935     pc->p[1] += Geom::Point(x, y);
 936     pen_redraw_all(pc);
 937 }
 938
 939 void
 940 pen_lastpoint_move_screen (SPPenContext *const pc, gdouble x, gdouble y)
 941 {
 942     pen_lastpoint_move (pc, x / pc->desktop->current_zoom(), y / pc->desktop->current_zoom());
 943 }
 944
 945 void
 946 pen_lastpoint_tocurve (SPPenContext *const pc)
 947 {
 948     if (pc->npoints != 5)
 949         return;
 950
 951     Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>( pc->green_curve->last_segment() );
 952     if ( cubic ) {
 953         pc->p[1] = pc->p[0] + (Geom::Point)( (*cubic)[3] - (*cubic)[2] );
 954     } else {
 955         pc->p[1] = pc->p[0] + (1./3)*(pc->p[3] - pc->p[0]);
 956     }
 957
 958     pen_redraw_all(pc);
 959 }
 960
 961 void
 962 pen_lastpoint_toline (SPPenContext *const pc)
 963 {
 964     if (pc->npoints != 5)
 965         return;
 966
 967     pc->p[1] = pc->p[0];
 968
 969     pen_redraw_all(pc);
 970 }
 971
 972
 973 static gint
 974 pen_handle_key_press(SPPenContext *const pc, GdkEvent *event)
 975 {
 976
 977         gint ret = FALSE;
 978     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 979     gdouble const nudge = prefs->getDoubleLimited("/options/nudgedistance/value", 2, 0, 1000); // in px
 980
 981     switch (get_group0_keyval (&event->key)) {
 982
 983         case GDK_Left: // move last point left
 984         case GDK_KP_Left:
 985         case GDK_KP_4:
 986             if (!MOD__CTRL) { // not ctrl
 987                 if (MOD__ALT) { // alt
 988                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, -10, 0); // shift
 989                     else pen_lastpoint_move_screen(pc, -1, 0); // no shift
 990                 }
 991                 else { // no alt
 992                     if (MOD__SHIFT) pen_lastpoint_move(pc, -10*nudge, 0); // shift
 993                     else pen_lastpoint_move(pc, -nudge, 0); // no shift
 994                 }
 995                 ret = TRUE;
 996             }
 997             break;
 998         case GDK_Up: // move last point up
 999         case GDK_KP_Up:
1000         case GDK_KP_8:
1001             if (!MOD__CTRL) { // not ctrl
1002                 if (MOD__ALT) { // alt
1003                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 0, 10); // shift
1004                     else pen_lastpoint_move_screen(pc, 0, 1); // no shift
1005                 }
1006                 else { // no alt
1007                     if (MOD__SHIFT) pen_lastpoint_move(pc, 0, 10*nudge); // shift
1008                     else pen_lastpoint_move(pc, 0, nudge); // no shift
1009                 }
1010                 ret = TRUE;
1011             }
1012             break;
1013         case GDK_Right: // move last point right
1014         case GDK_KP_Right:
1015         case GDK_KP_6:
1016             if (!MOD__CTRL) { // not ctrl
1017                 if (MOD__ALT) { // alt
1018                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 10, 0); // shift
1019                     else pen_lastpoint_move_screen(pc, 1, 0); // no shift
1020                 }
1021                 else { // no alt
1022                     if (MOD__SHIFT) pen_lastpoint_move(pc, 10*nudge, 0); // shift
1023                     else pen_lastpoint_move(pc, nudge, 0); // no shift
1024                 }
1025                 ret = TRUE;
1026             }
1027             break;
1028         case GDK_Down: // move last point down
1029         case GDK_KP_Down:
1030         case GDK_KP_2:
1031             if (!MOD__CTRL) { // not ctrl
1032                 if (MOD__ALT) { // alt
1033                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 0, -10); // shift
1034                     else pen_lastpoint_move_screen(pc, 0, -1); // no shift
1035                 }
1036                 else { // no alt
1037                     if (MOD__SHIFT) pen_lastpoint_move(pc, 0, -10*nudge); // shift
1038                     else pen_lastpoint_move(pc, 0, -nudge); // no shift
1039                 }
1040                 ret = TRUE;
1041             }
1042             break;
1043
1044         case GDK_P:
1045         case GDK_p:
1046             if (MOD__SHIFT_ONLY) {
1047                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::PARALLEL, 2);
1048                 ret = TRUE;
1049             }
1050             break;
1051
1052         case GDK_C:
1053         case GDK_c:
1054             if (MOD__SHIFT_ONLY) {
1055                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::CIRCLE_3PTS, 3);
1056                 ret = TRUE;
1057             }
1058             break;
1059
1060         case GDK_B:
1061         case GDK_b:
1062             if (MOD__SHIFT_ONLY) {
1063                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::PERP_BISECTOR, 2);
1064                 ret = TRUE;
1065             }
1066             break;
1067
1068         case GDK_A:
1069         case GDK_a:
1070             if (MOD__SHIFT_ONLY) {
1071                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::ANGLE_BISECTOR, 3);
1072                 ret = TRUE;
1073             }
1074             break;
1075
1076         case GDK_U:
1077         case GDK_u:
1078             if (MOD__SHIFT_ONLY) {
1079                 pen_lastpoint_tocurve(pc);
1080                 ret = TRUE;
1081             }
1082             break;
1083         case GDK_L:
1084         case GDK_l:
1085             if (MOD__SHIFT_ONLY) {
1086                 pen_lastpoint_toline(pc);
1087                 ret = TRUE;
1088             }
1089             break;
1090
1091         case GDK_Return:
1092         case GDK_KP_Enter:
1093             if (pc->npoints != 0) {
1094                 spdc_pen_finish(pc, FALSE);
1095                 ret = TRUE;
1096             }
1097             break;
1098         case GDK_Escape:
1099             if (pc->npoints != 0) {
1100                 // if drawing, cancel, otherwise pass it up for deselecting
1101                 pen_cancel (pc);
1102                 ret = TRUE;
1103             }
1104             break;
1105         case GDK_z:
1106         case GDK_Z:
1107             if (MOD__CTRL_ONLY && pc->npoints != 0) {
1108                 // if drawing, cancel, otherwise pass it up for undo
1109                 pen_cancel (pc);
1110                 ret = TRUE;
1111             }
1112             break;
1113         case GDK_g:
1114         case GDK_G:
1115             if (MOD__SHIFT_ONLY) {
1116                 sp_selection_to_guides(SP_EVENT_CONTEXT(pc)->desktop);
1117                 ret = true;
1118             }
1119             break;
1120         case GDK_BackSpace:
1121         case GDK_Delete:
1122         case GDK_KP_Delete:
1123             if ( pc->green_curve->is_empty() || (pc->green_curve->last_segment() == NULL) ) {
1124                 if (!pc->red_curve->is_empty()) {
1125                     pen_cancel (pc);
1126                     ret = TRUE;
1127                 } else {
1128                     // do nothing; this event should be handled upstream
1129                 }
1130             } else {
1131                 /* Reset red curve */
1132                 pc->red_curve->reset();
1133                 /* Destroy topmost green bpath */
1134                 if (pc->green_bpaths) {
1135                     if (pc->green_bpaths->data)
1136                         gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
1137                     pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
1138                 }
1139                 /* Get last segment */
1140                 if ( pc->green_curve->is_empty() ) {
1141                     g_warning("pen_handle_key_press, case GDK_KP_Delete: Green curve is empty");
1142                     break;
1143                 }
1144                 // The code below assumes that pc->green_curve has only ONE path !
1145                 Geom::Curve const * crv = pc->green_curve->last_segment();
1146                 pc->p[0] = crv->initialPoint();
1147                 if ( Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>(crv)) {
1148                     pc->p[1] = (*cubic)[1];
1149                 } else {
1150                     pc->p[1] = pc->p[0];
1151                 }
1152                 Geom::Point const pt(( pc->npoints < 4
1153                                      ? (Geom::Point)(crv->finalPoint())
1154                                      : pc->p[3] ));
1155                 pc->npoints = 2;
1156                 pc->green_curve->backspace();
1157                 sp_canvas_item_hide(pc->c0);
1158                 sp_canvas_item_hide(pc->c1);
1159                 sp_canvas_item_hide(pc->cl0);
1160                 sp_canvas_item_hide(pc->cl1);
1161                 pc->state = SP_PEN_CONTEXT_POINT;
1162                 spdc_pen_set_subsequent_point(pc, pt, true);
1163                 ret = TRUE;
1164             }
1165             break;
1166         default:
1167             break;
1168     }
1169     return ret;
1170 }
1171
1172 static void
1173 spdc_reset_colors(SPPenContext *pc)
1174 {
1175     /* Red */
1176     pc->red_curve->reset();
1177     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
1178     /* Blue */
1179     pc->blue_curve->reset();
1180     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->blue_bpath), NULL);
1181     /* Green */
1182     while (pc->green_bpaths) {
1183         gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
1184         pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
1185     }
1186     pc->green_curve->reset();
1187     if (pc->green_anchor) {
1188         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
1189     }
1190     pc->sa = NULL;
1191     pc->ea = NULL;
1192     pc->npoints = 0;
1193     pc->red_curve_is_valid = false;
1194 }
1195
1196
1197 static void
1198 spdc_pen_set_initial_point(SPPenContext *const pc, Geom::Point const p)
1199 {
1200     g_assert( pc->npoints == 0 );
1201
1202     pc->p[0] = p;
1203     pc->p[1] = p;
1204     pc->npoints = 2;
1205     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
1206
1207     sp_canvas_force_full_redraw_after_interruptions(pc->desktop->canvas, 5);
1208 }
1209
1210 /**
1211  * Show the status message for the current line/curve segment.
1212  * This type of message always shows angle/distance as the last
1213  * two parameters ("angle %3.2f&#176;, distance %s").
1214  */
1215 static void
1216 spdc_pen_set_angle_distance_status_message(SPPenContext *const pc, Geom::Point const p, int pc_point_to_compare, gchar const *message)
1217 {
1218     g_assert(pc != NULL);
1219     g_assert((pc_point_to_compare == 0) || (pc_point_to_compare == 3)); // exclude control handles
1220     g_assert(message != NULL);
1221
1222     SPDesktop *desktop = SP_EVENT_CONTEXT(pc)->desktop;
1223     Geom::Point rel = p - pc->p[pc_point_to_compare];
1224     GString *dist = SP_PX_TO_METRIC_STRING(Geom::L2(rel), desktop->namedview->getDefaultMetric());
1225     double angle = atan2(rel[Geom::Y], rel[Geom::X]) * 180 / M_PI;
1226     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
1227     if (prefs->getBool("/options/compassangledisplay/value", 0) != 0)
1228         angle = angle_to_compass (angle);
1229
1230     pc->_message_context->setF(Inkscape::IMMEDIATE_MESSAGE, message, angle, dist->str);
1231     g_string_free(dist, FALSE);
1232 }
1233
1234 static void
1235 spdc_pen_set_subsequent_point(SPPenContext *const pc, Geom::Point const p, bool statusbar, guint status)
1236 {
1237     g_assert( pc->npoints != 0 );
1238     /* todo: Check callers to see whether 2 <= npoints is guaranteed. */
1239
1240     pc->p[2] = p;
1241     pc->p[3] = p;
1242     pc->p[4] = p;
1243     pc->npoints = 5;
1244     pc->red_curve->reset();
1245     bool is_curve;
1246     pc->red_curve->moveto(pc->p[0]);
1247     if (pc->polylines_paraxial && !statusbar) {
1248         // we are drawing horizontal/vertical lines and hit an anchor; draw an L-shaped path
1249         Geom::Point intermed = p;
1250         pen_set_to_nearest_horiz_vert(pc, intermed, status);
1251         pc->red_curve->lineto(intermed);
1252         pc->red_curve->lineto(p);
1253         is_curve = false;
1254     } else {
1255         // one of the 'regular' modes
1256         if (pc->p[1] != pc->p[0])
1257         {
1258             pc->red_curve->curveto(pc->p[1], p, p);
1259             is_curve = true;
1260         } else {
1261             pc->red_curve->lineto(p);
1262             is_curve = false;
1263         }
1264     }
1265
1266     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
1267
1268     if (statusbar) {
1269         gchar *message = is_curve ?
1270             _("<b>Curve segment</b>: angle %3.2f&#176;, distance %s; with <b>Ctrl</b> to snap angle, <b>Enter</b> to finish the path" ):
1271             _("<b>Line segment</b>: angle %3.2f&#176;, distance %s; with <b>Ctrl</b> to snap angle, <b>Enter</b> to finish the path");
1272         spdc_pen_set_angle_distance_status_message(pc, p, 0, message);
1273     }
1274 }
1275
1276 static void
1277 spdc_pen_set_ctrl(SPPenContext *const pc, Geom::Point const p, guint const state)
1278 {
1279     sp_canvas_item_show(pc->c1);
1280     sp_canvas_item_show(pc->cl1);
1281
1282     if ( pc->npoints == 2 ) {
1283         pc->p[1] = p;
1284         sp_canvas_item_hide(pc->c0);
1285         sp_canvas_item_hide(pc->cl0);
1286         SP_CTRL(pc->c1)->moveto(pc->p[1]);
1287         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[0], pc->p[1]);
1288
1289         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"));
1290     } else if ( pc->npoints == 5 ) {
1291         pc->p[4] = p;
1292         sp_canvas_item_show(pc->c0);
1293         sp_canvas_item_show(pc->cl0);
1294         bool is_symm = false;
1295         if ( ( ( pc->mode == SP_PEN_CONTEXT_MODE_CLICK ) && ( state & GDK_CONTROL_MASK ) ) ||
1296              ( ( pc->mode == SP_PEN_CONTEXT_MODE_DRAG ) &&  !( state & GDK_SHIFT_MASK  ) ) ) {
1297             Geom::Point delta = p - pc->p[3];
1298             pc->p[2] = pc->p[3] - delta;
1299             is_symm = true;
1300             pc->red_curve->reset();
1301             pc->red_curve->moveto(pc->p[0]);
1302             pc->red_curve->curveto(pc->p[1], pc->p[2], pc->p[3]);
1303             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
1304         }
1305         SP_CTRL(pc->c0)->moveto(pc->p[2]);
1306         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl0), pc->p[3], pc->p[2]);
1307         SP_CTRL(pc->c1)->moveto(pc->p[4]);
1308         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[3], pc->p[4]);
1309
1310         gchar *message = is_symm ?
1311             _("<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") :
1312             _("<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");
1313         spdc_pen_set_angle_distance_status_message(pc, p, 3, message);
1314     } else {
1315         g_warning("Something bad happened - npoints is %d", pc->npoints);
1316     }
1317 }
1318
1319 static void
1320 spdc_pen_finish_segment(SPPenContext *const pc, Geom::Point const p, guint const state)
1321 {
1322     if (pc->polylines_paraxial) {
1323         pen_last_paraxial_dir = pen_next_paraxial_direction(pc, p, pc->p[0], state);
1324     }
1325     ++pc->num_clicks;
1326
1327     if (!pc->red_curve->is_empty()) {
1328         pc->green_curve->append_continuous(pc->red_curve, 0.0625);
1329         SPCurve *curve = pc->red_curve->copy();
1330         /// \todo fixme:
1331         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), curve);
1332         curve->unref();
1333         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
1334
1335         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
1336
1337         pc->p[0] = pc->p[3];
1338         pc->p[1] = pc->p[4];
1339         pc->npoints = 2;
1340
1341         pc->red_curve->reset();
1342     }
1343 }
1344
1345 static void
1346 spdc_pen_finish(SPPenContext *const pc, gboolean const closed)
1347 {
1348     if (pc->expecting_clicks_for_LPE > 1) {
1349         // don't let the path be finished before we have collected the required number of mouse clicks
1350         return;
1351     }
1352
1353     pc->num_clicks = 0;
1354
1355     pen_disable_events(pc);
1356
1357     SPDesktop *const desktop = pc->desktop;
1358     pc->_message_context->clear();
1359     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Drawing finished"));
1360
1361     pc->red_curve->reset();
1362     spdc_concat_colors_and_flush(pc, closed);
1363     pc->sa = NULL;
1364     pc->ea = NULL;
1365
1366     pc->npoints = 0;
1367     pc->state = SP_PEN_CONTEXT_POINT;
1368
1369     sp_canvas_item_hide(pc->c0);
1370     sp_canvas_item_hide(pc->c1);
1371     sp_canvas_item_hide(pc->cl0);
1372     sp_canvas_item_hide(pc->cl1);
1373
1374     if (pc->green_anchor) {
1375         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
1376     }
1377
1378
1379     sp_canvas_end_forced_full_redraws(pc->desktop->canvas);
1380
1381     pen_enable_events(pc);
1382 }
1383
1384 static void
1385 pen_disable_events(SPPenContext *const pc) {
1386   pc->events_disabled++;
1387 }
1388
1389 static void
1390 pen_enable_events(SPPenContext *const pc) {
1391   g_return_if_fail(pc->events_disabled != 0);
1392
1393   pc->events_disabled--;
1394 }
1395
1396 void
1397 sp_pen_context_wait_for_LPE_mouse_clicks(SPPenContext *pc, Inkscape::LivePathEffect::EffectType effect_type,
1398                                          unsigned int num_clicks, bool use_polylines)
1399 {
1400     if (effect_type == Inkscape::LivePathEffect::INVALID_LPE)
1401         return;
1402
1403     pc->waiting_LPE_type = effect_type;
1404     pc->expecting_clicks_for_LPE = num_clicks;
1405     pc->polylines_only = use_polylines;
1406     pc->polylines_paraxial = false; // TODO: think if this is correct for all cases
1407 }
1408
1409 void
1410 sp_pen_context_cancel_waiting_for_LPE(SPPenContext *pc)
1411 {
1412     pc->waiting_LPE_type = Inkscape::LivePathEffect::INVALID_LPE;
1413     pc->expecting_clicks_for_LPE = 0;
1414     sp_pen_context_set_polyline_mode(pc);
1415 }
1416
1417 static int pen_next_paraxial_direction(const SPPenContext *const pc,
1418                                        Geom::Point const &pt, Geom::Point const &origin, guint state) {
1419     /*
1420      * after the first mouse click we determine whether the mouse pointer is closest to a
1421      * horizontal or vertical segment; for all subsequent mouse clicks, we use the direction
1422      * orthogonal to the last one; pressing Shift toggles the direction
1423      */
1424     if (pc->num_clicks == 0) {
1425         // first mouse click
1426         double dist_h = fabs(pt[Geom::X] - origin[Geom::X]);
1427         double dist_v = fabs(pt[Geom::Y] - origin[Geom::Y]);
1428         int ret = (dist_h < dist_v) ? 1 : 0; // 0 = horizontal, 1 = vertical
1429         pen_last_paraxial_dir = (state & GDK_SHIFT_MASK) ? 1 - ret : ret;
1430         return pen_last_paraxial_dir;
1431     } else {
1432         // subsequent mouse click
1433         return (state & GDK_SHIFT_MASK) ? pen_last_paraxial_dir : 1 - pen_last_paraxial_dir;
1434     }
1435 }
1436
1437 void pen_set_to_nearest_horiz_vert(const SPPenContext *const pc, Geom::Point &pt, guint const state)
1438 {
1439     Geom::Point const &origin = pc->p[0];
1440
1441     int next_dir = pen_next_paraxial_direction(pc, pt, origin, state);
1442
1443     if (next_dir == 0) {
1444         // line is forced to be horizontal
1445         pt[Geom::Y] = origin[Geom::Y];
1446     } else {
1447         // line is forced to be vertical
1448         pt[Geom::X] = origin[Geom::X];
1449     }
1450 }
1451
1452 /*
1453   Local Variables:
1454   mode:c++
1455   c-file-style:"stroustrup"
1456   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1457   indent-tabs-mode:nil
1458   fill-column:99
1459   End:
1460 */
1461 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :