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