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