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     if (((SPEventContextClass *) pen_parent_class)->setup) {
 212         ((SPEventContextClass *) pen_parent_class)->setup(ec);
 213     }
 214
 215     /* Pen indicators */
 216     pc->c0 = sp_canvas_item_new(sp_desktop_controls(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRL, "shape", SP_CTRL_SHAPE_CIRCLE,
 217                                 "size", 4.0, "filled", 0, "fill_color", 0xff00007f, "stroked", 1, "stroke_color", 0x0000ff7f, NULL);
 218     pc->c1 = sp_canvas_item_new(sp_desktop_controls(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRL, "shape", SP_CTRL_SHAPE_CIRCLE,
 219                                 "size", 4.0, "filled", 0, "fill_color", 0xff00007f, "stroked", 1, "stroke_color", 0x0000ff7f, NULL);
 220     pc->cl0 = sp_canvas_item_new(sp_desktop_controls(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRLLINE, NULL);
 221     sp_ctrlline_set_rgba32(SP_CTRLLINE(pc->cl0), 0x0000007f);
 222     pc->cl1 = sp_canvas_item_new(sp_desktop_controls(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRLLINE, NULL);
 223     sp_ctrlline_set_rgba32(SP_CTRLLINE(pc->cl1), 0x0000007f);
 224
 225     sp_canvas_item_hide(pc->c0);
 226     sp_canvas_item_hide(pc->c1);
 227     sp_canvas_item_hide(pc->cl0);
 228     sp_canvas_item_hide(pc->cl1);
 229
 230     sp_event_context_read(ec, "mode");
 231
 232     pc->anchor_statusbar = false;
 233
 234     sp_pen_context_set_polyline_mode(pc);
 235
 236     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 237     if (prefs->getBool("/tools/freehand/pen/selcue")) {
 238         ec->enableSelectionCue();
 239     }
 240 }
 241
 242 static void
 243 pen_cancel (SPPenContext *const pc)
 244 {
 245     pc->num_clicks = 0;
 246     pc->state = SP_PEN_CONTEXT_STOP;
 247     spdc_reset_colors(pc);
 248     sp_canvas_item_hide(pc->c0);
 249     sp_canvas_item_hide(pc->c1);
 250     sp_canvas_item_hide(pc->cl0);
 251     sp_canvas_item_hide(pc->cl1);
 252     pc->_message_context->clear();
 253     pc->_message_context->flash(Inkscape::NORMAL_MESSAGE, _("Drawing cancelled"));
 254
 255     sp_canvas_end_forced_full_redraws(pc->desktop->canvas);
 256 }
 257
 258 /**
 259  * Finalization callback.
 260  */
 261 static void
 262 sp_pen_context_finish(SPEventContext *ec)
 263 {
 264     SPPenContext *pc = SP_PEN_CONTEXT(ec);
 265
 266     sp_event_context_discard_delayed_snap_event(ec);
 267
 268     if (pc->npoints != 0) {
 269         pen_cancel (pc);
 270     }
 271
 272     if (((SPEventContextClass *) pen_parent_class)->finish) {
 273         ((SPEventContextClass *) pen_parent_class)->finish(ec);
 274     }
 275 }
 276
 277 /**
 278  * Callback that sets key to value in pen context.
 279  */
 280 static void
 281 sp_pen_context_set(SPEventContext *ec, Inkscape::Preferences::Entry *val)
 282 {
 283     SPPenContext *pc = SP_PEN_CONTEXT(ec);
 284     Glib::ustring name = val->getEntryName();
 285
 286     if (name == "mode") {
 287         if ( val->getString() == "drag" ) {
 288             pc->mode = SP_PEN_CONTEXT_MODE_DRAG;
 289         } else {
 290             pc->mode = SP_PEN_CONTEXT_MODE_CLICK;
 291         }
 292     }
 293 }
 294
 295 /**
 296  * Snaps new node relative to the previous node.
 297  */
 298 static void
 299 spdc_endpoint_snap(SPPenContext const *const pc, Geom::Point &p, guint const state)
 300 {
 301     if ((state & GDK_CONTROL_MASK)) { //CTRL enables angular snapping
 302         if (pc->npoints > 0) {
 303             spdc_endpoint_snap_rotation(pc, p, pc->p[0], state);
 304         }
 305     } else {
 306         if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above
 307                                          //After all, the user explicitely asked for angular snapping by
 308                                          //pressing CTRL
 309             spdc_endpoint_snap_free(pc, p, state);
 310         }
 311     }
 312     if (pc->polylines_paraxial) {
 313         // TODO: must we avoid one of the snaps in the previous case distinction in some situations?
 314         pen_set_to_nearest_horiz_vert(pc, p, state);
 315     }
 316 }
 317
 318 /**
 319  * Snaps new node's handle relative to the new node.
 320  */
 321 static void
 322 spdc_endpoint_snap_handle(SPPenContext const *const pc, Geom::Point &p, guint const state)
 323 {
 324     g_return_if_fail(( pc->npoints == 2 ||
 325                        pc->npoints == 5   ));
 326
 327     if ((state & GDK_CONTROL_MASK)) { //CTRL enables angular snapping
 328         spdc_endpoint_snap_rotation(pc, p, pc->p[pc->npoints - 2], state);
 329     } else {
 330         if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above
 331             spdc_endpoint_snap_free(pc, p, state);
 332         }
 333     }
 334 }
 335
 336 static gint
 337 sp_pen_context_item_handler(SPEventContext *ec, SPItem *item, GdkEvent *event)
 338 {
 339     SPPenContext *const pc = SP_PEN_CONTEXT(ec);
 340
 341     gint ret = FALSE;
 342
 343     switch (event->type) {
 344         case GDK_BUTTON_PRESS:
 345             ret = pen_handle_button_press(pc, event->button);
 346             break;
 347         case GDK_BUTTON_RELEASE:
 348             ret = pen_handle_button_release(pc, event->button);
 349             break;
 350         default:
 351             break;
 352     }
 353
 354     if (!ret) {
 355         if (((SPEventContextClass *) pen_parent_class)->item_handler)
 356             ret = ((SPEventContextClass *) pen_parent_class)->item_handler(ec, item, event);
 357     }
 358
 359     return ret;
 360 }
 361
 362 /**
 363  * Callback to handle all pen events.
 364  */
 365 static gint
 366 sp_pen_context_root_handler(SPEventContext *ec, GdkEvent *event)
 367 {
 368     SPPenContext *const pc = SP_PEN_CONTEXT(ec);
 369
 370     gint ret = FALSE;
 371
 372     switch (event->type) {
 373         case GDK_BUTTON_PRESS:
 374             ret = pen_handle_button_press(pc, event->button);
 375             break;
 376
 377         case GDK_MOTION_NOTIFY:
 378             ret = pen_handle_motion_notify(pc, event->motion);
 379             break;
 380
 381         case GDK_BUTTON_RELEASE:
 382             ret = pen_handle_button_release(pc, event->button);
 383             break;
 384
 385         case GDK_2BUTTON_PRESS:
 386             ret = pen_handle_2button_press(pc, event->button);
 387             break;
 388
 389         case GDK_KEY_PRESS:
 390             ret = pen_handle_key_press(pc, event);
 391             break;
 392
 393         default:
 394             break;
 395     }
 396
 397     if (!ret) {
 398         gint (*const parent_root_handler)(SPEventContext *, GdkEvent *)
 399             = ((SPEventContextClass *) pen_parent_class)->root_handler;
 400         if (parent_root_handler) {
 401             ret = parent_root_handler(ec, event);
 402         }
 403     }
 404
 405     return ret;
 406 }
 407
 408 /**
 409  * Handle mouse button press event.
 410  */
 411 static gint pen_handle_button_press(SPPenContext *const pc, GdkEventButton const &bevent)
 412 {
 413     if (pc->events_disabled) {
 414         // skip event processing if events are disabled
 415         return FALSE;
 416     }
 417
 418     SPDrawContext * const dc = SP_DRAW_CONTEXT(pc);
 419     SPDesktop * const desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 420     Geom::Point const event_w(bevent.x, bevent.y);
 421     Geom::Point event_dt(desktop->w2d(event_w));
 422     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 423
 424     gint ret = FALSE;
 425     if (bevent.button == 1 && !event_context->space_panning
 426         // make sure this is not the last click for a waiting LPE (otherwise we want to finish the path)
 427         && pc->expecting_clicks_for_LPE != 1) {
 428
 429         if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 430             return TRUE;
 431         }
 432
 433         if (!pc->grab ) {
 434             /* Grab mouse, so release will not pass unnoticed */
 435             pc->grab = SP_CANVAS_ITEM(desktop->acetate);
 436             sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK   |
 437                                             GDK_BUTTON_RELEASE_MASK |
 438                                             GDK_POINTER_MOTION_MASK  ),
 439                                 NULL, bevent.time);
 440         }
 441
 442         pen_drag_origin_w = event_w;
 443         pen_within_tolerance = true;
 444
 445         /* Test whether we hit any anchor. */
 446         SPDrawAnchor * const anchor = spdc_test_inside(pc, event_w);
 447
 448         switch (pc->mode) {
 449             case SP_PEN_CONTEXT_MODE_CLICK:
 450                 /* In click mode we add point on release */
 451                 switch (pc->state) {
 452                     case SP_PEN_CONTEXT_POINT:
 453                     case SP_PEN_CONTEXT_CONTROL:
 454                     case SP_PEN_CONTEXT_CLOSE:
 455                         break;
 456                     case SP_PEN_CONTEXT_STOP:
 457                         /* This is allowed, if we just canceled curve */
 458                         pc->state = SP_PEN_CONTEXT_POINT;
 459                         break;
 460                     default:
 461                         break;
 462                 }
 463                 break;
 464             case SP_PEN_CONTEXT_MODE_DRAG:
 465                 switch (pc->state) {
 466                     case SP_PEN_CONTEXT_STOP:
 467                         /* This is allowed, if we just canceled curve */
 468                     case SP_PEN_CONTEXT_POINT:
 469                         if (pc->npoints == 0) {
 470
 471                                 Geom::Point p;
 472                           if ((bevent.state & GDK_CONTROL_MASK) && (pc->polylines_only || pc->polylines_paraxial)) {
 473                                 p = event_dt;
 474                                 if (!(bevent.state & GDK_SHIFT_MASK)) {
 475                                         SnapManager &m = desktop->namedview->snap_manager;
 476                                         m.setup(desktop);
 477                                                                         m.freeSnapReturnByRef(Inkscape::SnapPreferences::SNAPPOINT_NODE, p, Inkscape::SNAPSOURCE_HANDLE);
 478                                 }
 479                               spdc_create_single_dot(event_context, p, "/tools/freehand/pen", bevent.state);
 480                               ret = TRUE;
 481                               break;
 482                           }
 483
 484                             // TODO: Perhaps it would be nicer to rearrange the following case
 485                             // distinction so that the case of a waiting LPE is treated separately
 486
 487                             /* Set start anchor */
 488                             pc->sa = anchor;
 489                             if (anchor && !sp_pen_context_has_waiting_LPE(pc)) {
 490                                 /* Adjust point to anchor if needed; if we have a waiting LPE, we need
 491                                    a fresh path to be created so don't continue an existing one */
 492                                 p = anchor->dp;
 493                                 desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Continuing selected path"));
 494                             } else {
 495                                 // This is the first click of a new curve; deselect item so that
 496                                 // this curve is not combined with it (unless it is drawn from its
 497                                 // anchor, which is handled by the sibling branch above)
 498                                 Inkscape::Selection * const selection = sp_desktop_selection(desktop);
 499                                 if (!(bevent.state & GDK_SHIFT_MASK) || sp_pen_context_has_waiting_LPE(pc)) {
 500                                     /* if we have a waiting LPE, we need a fresh path to be created
 501                                        so don't append to an existing one */
 502                                     selection->clear();
 503                                     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Creating new path"));
 504                                 } else if (selection->singleItem() && SP_IS_PATH(selection->singleItem())) {
 505                                     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Appending to selected path"));
 506                                 }
 507
 508                                 /* Create green anchor */
 509                                 p = event_dt;
 510                                 if (!pc->polylines_paraxial) {
 511                                     // only snap the starting point if we're not in horizontal/vertical mode
 512                                     // because otherwise it gets shifted; TODO: why do we snap here at all??
 513                                     spdc_endpoint_snap(pc, p, bevent.state);
 514                                 }
 515                                 pc->green_anchor = sp_draw_anchor_new(pc, pc->green_curve, TRUE, p);
 516                             }
 517                             spdc_pen_set_initial_point(pc, p);
 518                         } else {
 519
 520                             /* Set end anchor */
 521                             pc->ea = anchor;
 522                             Geom::Point p;
 523                             if (anchor) {
 524                                 p = anchor->dp;
 525                                 // we hit an anchor, will finish the curve (either with or without closing)
 526                                 // in release handler
 527                                 pc->state = SP_PEN_CONTEXT_CLOSE;
 528
 529                                 if (pc->green_anchor && pc->green_anchor->active) {
 530                                     // we clicked on the current curve start, so close it even if
 531                                     // we drag a handle away from it
 532                                     dc->green_closed = TRUE;
 533                                 }
 534                                 ret = TRUE;
 535                                 break;
 536
 537                             } else {
 538                                 p = event_dt;
 539                                 spdc_endpoint_snap(pc, p, bevent.state); /* Snap node only if not hitting anchor. */
 540                                 spdc_pen_set_subsequent_point(pc, p, true);
 541                                 if (pc->polylines_only) {
 542                                     spdc_pen_finish_segment(pc, p, bevent.state);
 543                                 }
 544                             }
 545                         }
 546
 547                         pc->state = pc->polylines_only ? SP_PEN_CONTEXT_POINT : SP_PEN_CONTEXT_CONTROL;
 548                         ret = TRUE;
 549                         break;
 550                     case SP_PEN_CONTEXT_CONTROL:
 551                         g_warning("Button down in CONTROL state");
 552                         break;
 553                     case SP_PEN_CONTEXT_CLOSE:
 554                         g_warning("Button down in CLOSE state");
 555                         break;
 556                     default:
 557                         break;
 558                 }
 559                 break;
 560             default:
 561                 break;
 562         }
 563     } 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
 564         if (pc->npoints != 0) {
 565
 566             spdc_pen_finish_segment(pc, event_dt, bevent.state);
 567             if (pc->green_closed) {
 568                 // finishing at the start anchor, close curve
 569                 spdc_pen_finish(pc, TRUE);
 570             } else {
 571                 // finishing at some other anchor, finish curve but not close
 572                 spdc_pen_finish(pc, FALSE);
 573             }
 574
 575             ret = TRUE;
 576         }
 577     }
 578
 579     if (pc->expecting_clicks_for_LPE > 0) {
 580         --pc->expecting_clicks_for_LPE;
 581     }
 582
 583     return ret;
 584 }
 585
 586 /**
 587  * Handle motion_notify event.
 588  */
 589 static gint
 590 pen_handle_motion_notify(SPPenContext *const pc, GdkEventMotion const &mevent)
 591 {
 592     gint ret = FALSE;
 593
 594     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 595     SPDesktop * const dt = SP_EVENT_CONTEXT_DESKTOP(event_context);
 596
 597     if (event_context->space_panning || mevent.state & GDK_BUTTON2_MASK || mevent.state & GDK_BUTTON3_MASK) {
 598         // allow scrolling
 599         return FALSE;
 600     }
 601
 602     if (pc->events_disabled) {
 603         // skip motion events if pen events are disabled
 604         return FALSE;
 605     }
 606
 607     Geom::Point const event_w(mevent.x,
 608                             mevent.y);
 609     if (pen_within_tolerance) {
 610         Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 611         gint const tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
 612         if ( Geom::LInfty( event_w - pen_drag_origin_w ) < tolerance ) {
 613             return FALSE;   // Do not drag if we're within tolerance from origin.
 614         }
 615     }
 616     // Once the user has moved farther than tolerance from the original location
 617     // (indicating they intend to move the object, not click), then always process the
 618     // motion notify coordinates as given (no snapping back to origin)
 619     pen_within_tolerance = false;
 620
 621     /* Find desktop coordinates */
 622     Geom::Point p = dt->w2d(event_w);
 623
 624     /* Test, whether we hit any anchor */
 625     SPDrawAnchor *anchor = spdc_test_inside(pc, event_w);
 626
 627     switch (pc->mode) {
 628         case SP_PEN_CONTEXT_MODE_CLICK:
 629             switch (pc->state) {
 630                 case SP_PEN_CONTEXT_POINT:
 631                     if ( pc->npoints != 0 ) {
 632                         /* Only set point, if we are already appending */
 633                         spdc_endpoint_snap(pc, p, mevent.state);
 634                         spdc_pen_set_subsequent_point(pc, p, true);
 635                         ret = TRUE;
 636                     }
 637                     break;
 638                 case SP_PEN_CONTEXT_CONTROL:
 639                 case SP_PEN_CONTEXT_CLOSE:
 640                     /* Placing controls is last operation in CLOSE state */
 641                     spdc_endpoint_snap(pc, p, mevent.state);
 642                     spdc_pen_set_ctrl(pc, p, mevent.state);
 643                     ret = TRUE;
 644                     break;
 645                 case SP_PEN_CONTEXT_STOP:
 646                     /* This is perfectly valid */
 647                     break;
 648                 default:
 649                     break;
 650             }
 651             break;
 652         case SP_PEN_CONTEXT_MODE_DRAG:
 653             switch (pc->state) {
 654                 case SP_PEN_CONTEXT_POINT:
 655                     if ( pc->npoints > 0 ) {
 656                         /* Only set point, if we are already appending */
 657
 658                         if (!anchor) {   /* Snap node only if not hitting anchor */
 659                             spdc_endpoint_snap(pc, p, mevent.state);
 660                         }
 661
 662                         spdc_pen_set_subsequent_point(pc, p, !anchor, mevent.state);
 663
 664                         if (anchor && !pc->anchor_statusbar) {
 665                             pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to close and finish the path."));
 666                             pc->anchor_statusbar = true;
 667                         } else if (!anchor && pc->anchor_statusbar) {
 668                             pc->_message_context->clear();
 669                             pc->anchor_statusbar = false;
 670                         }
 671
 672                         ret = TRUE;
 673                     } else {
 674                         if (anchor && !pc->anchor_statusbar) {
 675                             pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to continue the path from this point."));
 676                             pc->anchor_statusbar = true;
 677                         } else if (!anchor && pc->anchor_statusbar) {
 678                             pc->_message_context->clear();
 679                             pc->anchor_statusbar = false;
 680                         }
 681                     }
 682                     break;
 683                 case SP_PEN_CONTEXT_CONTROL:
 684                 case SP_PEN_CONTEXT_CLOSE:
 685                     /* Placing controls is last operation in CLOSE state */
 686
 687                     // snap the handle
 688                     spdc_endpoint_snap_handle(pc, p, mevent.state);
 689
 690                     if (!pc->polylines_only) {
 691                         spdc_pen_set_ctrl(pc, p, mevent.state);
 692                     } else {
 693                         spdc_pen_set_ctrl(pc, pc->p[1], mevent.state);
 694                     }
 695                     gobble_motion_events(GDK_BUTTON1_MASK);
 696                     ret = TRUE;
 697                     break;
 698                 case SP_PEN_CONTEXT_STOP:
 699                     /* This is perfectly valid */
 700                     break;
 701                 default:
 702                     break;
 703             }
 704             break;
 705         default:
 706             break;
 707     }
 708     return ret;
 709 }
 710
 711 /**
 712  * Handle mouse button release event.
 713  */
 714 static gint
 715 pen_handle_button_release(SPPenContext *const pc, GdkEventButton const &revent)
 716 {
 717     if (pc->events_disabled) {
 718         // skip event processing if events are disabled
 719         return FALSE;
 720     }
 721
 722     gint ret = FALSE;
 723     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 724     if ( revent.button == 1  && !event_context->space_panning) {
 725
 726         SPDrawContext *dc = SP_DRAW_CONTEXT (pc);
 727
 728         Geom::Point const event_w(revent.x,
 729                                 revent.y);
 730         /* Find desktop coordinates */
 731         Geom::Point p = pc->desktop->w2d(event_w);
 732
 733         /* Test whether we hit any anchor. */
 734         SPDrawAnchor *anchor = spdc_test_inside(pc, event_w);
 735
 736         switch (pc->mode) {
 737             case SP_PEN_CONTEXT_MODE_CLICK:
 738                 switch (pc->state) {
 739                     case SP_PEN_CONTEXT_POINT:
 740                         if ( pc->npoints == 0 ) {
 741                             /* Start new thread only with button release */
 742                             if (anchor) {
 743                                 p = anchor->dp;
 744                             }
 745                             pc->sa = anchor;
 746                             spdc_pen_set_initial_point(pc, p);
 747                         } else {
 748                             /* Set end anchor here */
 749                             pc->ea = anchor;
 750                             if (anchor) {
 751                                 p = anchor->dp;
 752                             }
 753                         }
 754                         pc->state = SP_PEN_CONTEXT_CONTROL;
 755                         ret = TRUE;
 756                         break;
 757                     case SP_PEN_CONTEXT_CONTROL:
 758                         /* End current segment */
 759                         spdc_endpoint_snap(pc, p, revent.state);
 760                         spdc_pen_finish_segment(pc, p, revent.state);
 761                         pc->state = SP_PEN_CONTEXT_POINT;
 762                         ret = TRUE;
 763                         break;
 764                     case SP_PEN_CONTEXT_CLOSE:
 765                         /* End current segment */
 766                         if (!anchor) {   /* Snap node only if not hitting anchor */
 767                             spdc_endpoint_snap(pc, p, revent.state);
 768                         }
 769                         spdc_pen_finish_segment(pc, p, revent.state);
 770                         spdc_pen_finish(pc, TRUE);
 771                         pc->state = SP_PEN_CONTEXT_POINT;
 772                         ret = TRUE;
 773                         break;
 774                     case SP_PEN_CONTEXT_STOP:
 775                         /* This is allowed, if we just canceled curve */
 776                         pc->state = SP_PEN_CONTEXT_POINT;
 777                         ret = TRUE;
 778                         break;
 779                     default:
 780                         break;
 781                 }
 782                 break;
 783             case SP_PEN_CONTEXT_MODE_DRAG:
 784                 switch (pc->state) {
 785                     case SP_PEN_CONTEXT_POINT:
 786                     case SP_PEN_CONTEXT_CONTROL:
 787                         if (!pc->polylines_only) {
 788                             spdc_endpoint_snap(pc, p, revent.state);
 789                             spdc_pen_finish_segment(pc, p, revent.state);
 790                         }
 791                         break;
 792                     case SP_PEN_CONTEXT_CLOSE:
 793                         spdc_endpoint_snap(pc, p, revent.state);
 794                         spdc_pen_finish_segment(pc, p, revent.state);
 795                         if (pc->green_closed) {
 796                             // finishing at the start anchor, close curve
 797                             spdc_pen_finish(pc, TRUE);
 798                         } else {
 799                             // finishing at some other anchor, finish curve but not close
 800                             spdc_pen_finish(pc, FALSE);
 801                         }
 802                         break;
 803                     case SP_PEN_CONTEXT_STOP:
 804                         /* This is allowed, if we just cancelled curve */
 805                         break;
 806                     default:
 807                         break;
 808                 }
 809                 pc->state = SP_PEN_CONTEXT_POINT;
 810                 ret = TRUE;
 811                 break;
 812             default:
 813                 break;
 814         }
 815
 816         if (pc->grab) {
 817             /* Release grab now */
 818             sp_canvas_item_ungrab(pc->grab, revent.time);
 819             pc->grab = NULL;
 820         }
 821
 822         ret = TRUE;
 823
 824         dc->green_closed = FALSE;
 825     }
 826
 827     // TODO: can we be sure that the path was created correctly?
 828     // TODO: should we offer an option to collect the clicks in a list?
 829     if (pc->expecting_clicks_for_LPE == 0 && sp_pen_context_has_waiting_LPE(pc)) {
 830         sp_pen_context_set_polyline_mode(pc);
 831
 832         SPEventContext *ec = SP_EVENT_CONTEXT(pc);
 833         Inkscape::Selection *selection = sp_desktop_selection (ec->desktop);
 834
 835         if (pc->waiting_LPE) {
 836             // we have an already created LPE waiting for a path
 837             pc->waiting_LPE->acceptParamPath(SP_PATH(selection->singleItem()));
 838             selection->add(SP_OBJECT(pc->waiting_item));
 839             pc->waiting_LPE = NULL;
 840         } else {
 841             // the case that we need to create a new LPE and apply it to the just-drawn path is
 842             // handled in spdc_check_for_and_apply_waiting_LPE() in draw-context.cpp
 843         }
 844     }
 845
 846     return ret;
 847 }
 848
 849 static gint
 850 pen_handle_2button_press(SPPenContext *const pc, GdkEventButton const &bevent)
 851 {
 852     gint ret = FALSE;
 853     // only end on LMB double click. Otherwise horizontal scrolling causes ending of the path
 854     if (pc->npoints != 0 && bevent.button == 1) {
 855         spdc_pen_finish(pc, FALSE);
 856         ret = TRUE;
 857     }
 858     return ret;
 859 }
 860
 861 void
 862 pen_redraw_all (SPPenContext *const pc)
 863 {
 864     // green
 865     if (pc->green_bpaths) {
 866         // remove old piecewise green canvasitems
 867         while (pc->green_bpaths) {
 868             gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
 869             pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
 870         }
 871         // one canvas bpath for all of green_curve
 872         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), pc->green_curve);
 873         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 874         sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cshape), 0, SP_WIND_RULE_NONZERO);
 875
 876         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
 877     }
 878
 879     if (pc->green_anchor)
 880         SP_CTRL(pc->green_anchor->ctrl)->moveto(pc->green_anchor->dp);
 881
 882     pc->red_curve->reset();
 883     pc->red_curve->moveto(pc->p[0]);
 884     pc->red_curve->curveto(pc->p[1], pc->p[2], pc->p[3]);
 885     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 886
 887     // handles
 888     if (pc->p[0] != pc->p[1]) {
 889         SP_CTRL(pc->c1)->moveto(pc->p[1]);
 890         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[0], pc->p[1]);
 891         sp_canvas_item_show (pc->c1);
 892         sp_canvas_item_show (pc->cl1);
 893     } else {
 894         sp_canvas_item_hide (pc->c1);
 895         sp_canvas_item_hide (pc->cl1);
 896     }
 897
 898     Geom::Curve const * last_seg = pc->green_curve->last_segment();
 899     if (last_seg) {
 900         Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>( last_seg );
 901         if ( cubic &&
 902              (*cubic)[2] != to_2geom(pc->p[0]) )
 903         {
 904             Geom::Point p2 = (*cubic)[2];
 905             SP_CTRL(pc->c0)->moveto(p2);
 906             sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl0), p2, pc->p[0]);
 907             sp_canvas_item_show (pc->c0);
 908             sp_canvas_item_show (pc->cl0);
 909         } else {
 910             sp_canvas_item_hide (pc->c0);
 911             sp_canvas_item_hide (pc->cl0);
 912         }
 913     }
 914 }
 915
 916 void
 917 pen_lastpoint_move (SPPenContext *const pc, gdouble x, gdouble y)
 918 {
 919     if (pc->npoints != 5)
 920         return;
 921
 922     // green
 923     if (!pc->green_curve->is_empty()) {
 924         pc->green_curve->last_point_additive_move( Geom::Point(x,y) );
 925     } else {
 926         // start anchor too
 927         if (pc->green_anchor) {
 928             pc->green_anchor->dp += Geom::Point(x, y);
 929         }
 930     }
 931
 932     // red
 933     pc->p[0] += Geom::Point(x, y);
 934     pc->p[1] += Geom::Point(x, y);
 935     pen_redraw_all(pc);
 936 }
 937
 938 void
 939 pen_lastpoint_move_screen (SPPenContext *const pc, gdouble x, gdouble y)
 940 {
 941     pen_lastpoint_move (pc, x / pc->desktop->current_zoom(), y / pc->desktop->current_zoom());
 942 }
 943
 944 void
 945 pen_lastpoint_tocurve (SPPenContext *const pc)
 946 {
 947     if (pc->npoints != 5)
 948         return;
 949
 950     Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>( pc->green_curve->last_segment() );
 951     if ( cubic ) {
 952         pc->p[1] = pc->p[0] + (Geom::Point)( (*cubic)[3] - (*cubic)[2] );
 953     } else {
 954         pc->p[1] = pc->p[0] + (1./3)*(pc->p[3] - pc->p[0]);
 955     }
 956
 957     pen_redraw_all(pc);
 958 }
 959
 960 void
 961 pen_lastpoint_toline (SPPenContext *const pc)
 962 {
 963     if (pc->npoints != 5)
 964         return;
 965
 966     pc->p[1] = pc->p[0];
 967
 968     pen_redraw_all(pc);
 969 }
 970
 971
 972 static gint
 973 pen_handle_key_press(SPPenContext *const pc, GdkEvent *event)
 974 {
 975
 976         gint ret = FALSE;
 977     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 978     gdouble const nudge = prefs->getDoubleLimited("/options/nudgedistance/value", 2, 0, 1000); // in px
 979
 980     switch (get_group0_keyval (&event->key)) {
 981
 982         case GDK_Left: // move last point left
 983         case GDK_KP_Left:
 984         case GDK_KP_4:
 985             if (!MOD__CTRL) { // not ctrl
 986                 if (MOD__ALT) { // alt
 987                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, -10, 0); // shift
 988                     else pen_lastpoint_move_screen(pc, -1, 0); // no shift
 989                 }
 990                 else { // no alt
 991                     if (MOD__SHIFT) pen_lastpoint_move(pc, -10*nudge, 0); // shift
 992                     else pen_lastpoint_move(pc, -nudge, 0); // no shift
 993                 }
 994                 ret = TRUE;
 995             }
 996             break;
 997         case GDK_Up: // move last point up
 998         case GDK_KP_Up:
 999         case GDK_KP_8:
1000             if (!MOD__CTRL) { // not ctrl
1001                 if (MOD__ALT) { // alt
1002                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 0, 10); // shift
1003                     else pen_lastpoint_move_screen(pc, 0, 1); // no shift
1004                 }
1005                 else { // no alt
1006                     if (MOD__SHIFT) pen_lastpoint_move(pc, 0, 10*nudge); // shift
1007                     else pen_lastpoint_move(pc, 0, nudge); // no shift
1008                 }
1009                 ret = TRUE;
1010             }
1011             break;
1012         case GDK_Right: // move last point right
1013         case GDK_KP_Right:
1014         case GDK_KP_6:
1015             if (!MOD__CTRL) { // not ctrl
1016                 if (MOD__ALT) { // alt
1017                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 10, 0); // shift
1018                     else pen_lastpoint_move_screen(pc, 1, 0); // no shift
1019                 }
1020                 else { // no alt
1021                     if (MOD__SHIFT) pen_lastpoint_move(pc, 10*nudge, 0); // shift
1022                     else pen_lastpoint_move(pc, nudge, 0); // no shift
1023                 }
1024                 ret = TRUE;
1025             }
1026             break;
1027         case GDK_Down: // move last point down
1028         case GDK_KP_Down:
1029         case GDK_KP_2:
1030             if (!MOD__CTRL) { // not ctrl
1031                 if (MOD__ALT) { // alt
1032                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 0, -10); // shift
1033                     else pen_lastpoint_move_screen(pc, 0, -1); // no shift
1034                 }
1035                 else { // no alt
1036                     if (MOD__SHIFT) pen_lastpoint_move(pc, 0, -10*nudge); // shift
1037                     else pen_lastpoint_move(pc, 0, -nudge); // no shift
1038                 }
1039                 ret = TRUE;
1040             }
1041             break;
1042
1043 /* TODO: this is not yet enabled?? looks like some traces of the Geometry tool
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
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 /*
1454   Local Variables:
1455   mode:c++
1456   c-file-style:"stroustrup"
1457   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1458   indent-tabs-mode:nil
1459   fill-column:99
1460   End:
1461 */
1462 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :