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                             }
 542                         }
 543
 544                         pc->state = pc->polylines_only ? SP_PEN_CONTEXT_POINT : SP_PEN_CONTEXT_CONTROL;
 545                         ret = TRUE;
 546                         break;
 547                     case SP_PEN_CONTEXT_CONTROL:
 548                         g_warning("Button down in CONTROL state");
 549                         break;
 550                     case SP_PEN_CONTEXT_CLOSE:
 551                         g_warning("Button down in CLOSE state");
 552                         break;
 553                     default:
 554                         break;
 555                 }
 556                 break;
 557             default:
 558                 break;
 559         }
 560     } 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
 561         if (pc->npoints != 0) {
 562
 563             spdc_pen_finish_segment(pc, event_dt, bevent.state);
 564             if (pc->green_closed) {
 565                 // finishing at the start anchor, close curve
 566                 spdc_pen_finish(pc, TRUE);
 567             } else {
 568                 // finishing at some other anchor, finish curve but not close
 569                 spdc_pen_finish(pc, FALSE);
 570             }
 571
 572             ret = TRUE;
 573         }
 574     }
 575
 576     if (pc->expecting_clicks_for_LPE > 0) {
 577         --pc->expecting_clicks_for_LPE;
 578     }
 579
 580     return ret;
 581 }
 582
 583 /**
 584  * Handle motion_notify event.
 585  */
 586 static gint
 587 pen_handle_motion_notify(SPPenContext *const pc, GdkEventMotion const &mevent)
 588 {
 589     gint ret = FALSE;
 590
 591     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 592     SPDesktop * const dt = SP_EVENT_CONTEXT_DESKTOP(event_context);
 593
 594     if (event_context->space_panning || mevent.state & GDK_BUTTON2_MASK || mevent.state & GDK_BUTTON3_MASK) {
 595         // allow scrolling
 596         return FALSE;
 597     }
 598
 599     if (pc->events_disabled) {
 600         // skip motion events if pen events are disabled
 601         return FALSE;
 602     }
 603
 604     Geom::Point const event_w(mevent.x,
 605                             mevent.y);
 606     if (pen_within_tolerance) {
 607         Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 608         gint const tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
 609         if ( Geom::LInfty( event_w - pen_drag_origin_w ) < tolerance ) {
 610             return FALSE;   // Do not drag if we're within tolerance from origin.
 611         }
 612     }
 613     // Once the user has moved farther than tolerance from the original location
 614     // (indicating they intend to move the object, not click), then always process the
 615     // motion notify coordinates as given (no snapping back to origin)
 616     pen_within_tolerance = false;
 617
 618     /* Find desktop coordinates */
 619     Geom::Point p = dt->w2d(event_w);
 620
 621     /* Test, whether we hit any anchor */
 622     SPDrawAnchor *anchor = spdc_test_inside(pc, event_w);
 623
 624     switch (pc->mode) {
 625         case SP_PEN_CONTEXT_MODE_CLICK:
 626             switch (pc->state) {
 627                 case SP_PEN_CONTEXT_POINT:
 628                     if ( pc->npoints != 0 ) {
 629                         /* Only set point, if we are already appending */
 630                         spdc_endpoint_snap(pc, p, mevent.state);
 631                         spdc_pen_set_subsequent_point(pc, p, true);
 632                         ret = TRUE;
 633                     }
 634                     break;
 635                 case SP_PEN_CONTEXT_CONTROL:
 636                 case SP_PEN_CONTEXT_CLOSE:
 637                     /* Placing controls is last operation in CLOSE state */
 638                     spdc_endpoint_snap(pc, p, mevent.state);
 639                     spdc_pen_set_ctrl(pc, p, mevent.state);
 640                     ret = TRUE;
 641                     break;
 642                 case SP_PEN_CONTEXT_STOP:
 643                     /* This is perfectly valid */
 644                     break;
 645                 default:
 646                     break;
 647             }
 648             break;
 649         case SP_PEN_CONTEXT_MODE_DRAG:
 650             switch (pc->state) {
 651                 case SP_PEN_CONTEXT_POINT:
 652                     if ( pc->npoints > 0 ) {
 653                         /* Only set point, if we are already appending */
 654
 655                         if (!anchor) {   /* Snap node only if not hitting anchor */
 656                             spdc_endpoint_snap(pc, p, mevent.state);
 657                         }
 658
 659                         spdc_pen_set_subsequent_point(pc, p, !anchor, mevent.state);
 660
 661                         if (anchor && !pc->anchor_statusbar) {
 662                             pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to close and finish the path."));
 663                             pc->anchor_statusbar = true;
 664                         } else if (!anchor && pc->anchor_statusbar) {
 665                             pc->_message_context->clear();
 666                             pc->anchor_statusbar = false;
 667                         }
 668
 669                         ret = TRUE;
 670                     } else {
 671                         if (anchor && !pc->anchor_statusbar) {
 672                             pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to continue the path from this point."));
 673                             pc->anchor_statusbar = true;
 674                         } else if (!anchor && pc->anchor_statusbar) {
 675                             pc->_message_context->clear();
 676                             pc->anchor_statusbar = false;
 677                         }
 678                     }
 679                     break;
 680                 case SP_PEN_CONTEXT_CONTROL:
 681                 case SP_PEN_CONTEXT_CLOSE:
 682                     /* Placing controls is last operation in CLOSE state */
 683
 684                     // snap the handle
 685                     spdc_endpoint_snap_handle(pc, p, mevent.state);
 686
 687                     if (!pc->polylines_only) {
 688                         spdc_pen_set_ctrl(pc, p, mevent.state);
 689                     } else {
 690                         spdc_pen_set_ctrl(pc, pc->p[1], mevent.state);
 691                     }
 692                     gobble_motion_events(GDK_BUTTON1_MASK);
 693                     ret = TRUE;
 694                     break;
 695                 case SP_PEN_CONTEXT_STOP:
 696                     /* This is perfectly valid */
 697                     break;
 698                 default:
 699                     break;
 700             }
 701             break;
 702         default:
 703             break;
 704     }
 705     return ret;
 706 }
 707
 708 /**
 709  * Handle mouse button release event.
 710  */
 711 static gint
 712 pen_handle_button_release(SPPenContext *const pc, GdkEventButton const &revent)
 713 {
 714     if (pc->events_disabled) {
 715         // skip event processing if events are disabled
 716         return FALSE;
 717     }
 718
 719     gint ret = FALSE;
 720     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 721     if ( revent.button == 1  && !event_context->space_panning) {
 722
 723         SPDrawContext *dc = SP_DRAW_CONTEXT (pc);
 724
 725         Geom::Point const event_w(revent.x,
 726                                 revent.y);
 727         /* Find desktop coordinates */
 728         Geom::Point p = pc->desktop->w2d(event_w);
 729
 730         /* Test whether we hit any anchor. */
 731         SPDrawAnchor *anchor = spdc_test_inside(pc, event_w);
 732
 733         switch (pc->mode) {
 734             case SP_PEN_CONTEXT_MODE_CLICK:
 735                 switch (pc->state) {
 736                     case SP_PEN_CONTEXT_POINT:
 737                         if ( pc->npoints == 0 ) {
 738                             /* Start new thread only with button release */
 739                             if (anchor) {
 740                                 p = anchor->dp;
 741                             }
 742                             pc->sa = anchor;
 743                             spdc_pen_set_initial_point(pc, p);
 744                         } else {
 745                             /* Set end anchor here */
 746                             pc->ea = anchor;
 747                             if (anchor) {
 748                                 p = anchor->dp;
 749                             }
 750                         }
 751                         pc->state = SP_PEN_CONTEXT_CONTROL;
 752                         ret = TRUE;
 753                         break;
 754                     case SP_PEN_CONTEXT_CONTROL:
 755                         /* End current segment */
 756                         spdc_endpoint_snap(pc, p, revent.state);
 757                         spdc_pen_finish_segment(pc, p, revent.state);
 758                         pc->state = SP_PEN_CONTEXT_POINT;
 759                         ret = TRUE;
 760                         break;
 761                     case SP_PEN_CONTEXT_CLOSE:
 762                         /* End current segment */
 763                         if (!anchor) {   /* Snap node only if not hitting anchor */
 764                             spdc_endpoint_snap(pc, p, revent.state);
 765                         }
 766                         spdc_pen_finish_segment(pc, p, revent.state);
 767                         spdc_pen_finish(pc, TRUE);
 768                         pc->state = SP_PEN_CONTEXT_POINT;
 769                         ret = TRUE;
 770                         break;
 771                     case SP_PEN_CONTEXT_STOP:
 772                         /* This is allowed, if we just canceled curve */
 773                         pc->state = SP_PEN_CONTEXT_POINT;
 774                         ret = TRUE;
 775                         break;
 776                     default:
 777                         break;
 778                 }
 779                 break;
 780             case SP_PEN_CONTEXT_MODE_DRAG:
 781                 switch (pc->state) {
 782                     case SP_PEN_CONTEXT_POINT:
 783                     case SP_PEN_CONTEXT_CONTROL:
 784                         spdc_endpoint_snap(pc, p, revent.state);
 785                         spdc_pen_finish_segment(pc, p, revent.state);
 786                         break;
 787                     case SP_PEN_CONTEXT_CLOSE:
 788                         spdc_endpoint_snap(pc, p, revent.state);
 789                         spdc_pen_finish_segment(pc, p, revent.state);
 790                         if (pc->green_closed) {
 791                             // finishing at the start anchor, close curve
 792                             spdc_pen_finish(pc, TRUE);
 793                         } else {
 794                             // finishing at some other anchor, finish curve but not close
 795                             spdc_pen_finish(pc, FALSE);
 796                         }
 797                         break;
 798                     case SP_PEN_CONTEXT_STOP:
 799                         /* This is allowed, if we just cancelled curve */
 800                         break;
 801                     default:
 802                         break;
 803                 }
 804                 pc->state = SP_PEN_CONTEXT_POINT;
 805                 ret = TRUE;
 806                 break;
 807             default:
 808                 break;
 809         }
 810
 811         if (pc->grab) {
 812             /* Release grab now */
 813             sp_canvas_item_ungrab(pc->grab, revent.time);
 814             pc->grab = NULL;
 815         }
 816
 817         ret = TRUE;
 818
 819         dc->green_closed = FALSE;
 820     }
 821
 822     // TODO: can we be sure that the path was created correctly?
 823     // TODO: should we offer an option to collect the clicks in a list?
 824     if (pc->expecting_clicks_for_LPE == 0 && sp_pen_context_has_waiting_LPE(pc)) {
 825         sp_pen_context_set_polyline_mode(pc);
 826
 827         SPEventContext *ec = SP_EVENT_CONTEXT(pc);
 828         Inkscape::Selection *selection = sp_desktop_selection (ec->desktop);
 829
 830         if (pc->waiting_LPE) {
 831             // we have an already created LPE waiting for a path
 832             pc->waiting_LPE->acceptParamPath(SP_PATH(selection->singleItem()));
 833             selection->add(SP_OBJECT(pc->waiting_item));
 834             pc->waiting_LPE = NULL;
 835         } else {
 836             // the case that we need to create a new LPE and apply it to the just-drawn path is
 837             // handled in spdc_check_for_and_apply_waiting_LPE() in draw-context.cpp
 838         }
 839     }
 840
 841     return ret;
 842 }
 843
 844 static gint
 845 pen_handle_2button_press(SPPenContext *const pc, GdkEventButton const &bevent)
 846 {
 847     gint ret = FALSE;
 848     // only end on LMB double click. Otherwise horizontal scrolling causes ending of the path
 849     if (pc->npoints != 0 && bevent.button == 1) {
 850         spdc_pen_finish(pc, FALSE);
 851         ret = TRUE;
 852     }
 853     return ret;
 854 }
 855
 856 void
 857 pen_redraw_all (SPPenContext *const pc)
 858 {
 859     // green
 860     if (pc->green_bpaths) {
 861         // remove old piecewise green canvasitems
 862         while (pc->green_bpaths) {
 863             gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
 864             pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
 865         }
 866         // one canvas bpath for all of green_curve
 867         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), pc->green_curve);
 868         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 869         sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cshape), 0, SP_WIND_RULE_NONZERO);
 870
 871         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
 872     }
 873
 874     if (pc->green_anchor)
 875         SP_CTRL(pc->green_anchor->ctrl)->moveto(pc->green_anchor->dp);
 876
 877     pc->red_curve->reset();
 878     pc->red_curve->moveto(pc->p[0]);
 879     pc->red_curve->curveto(pc->p[1], pc->p[2], pc->p[3]);
 880     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 881
 882     // handles
 883     if (pc->p[0] != pc->p[1]) {
 884         SP_CTRL(pc->c1)->moveto(pc->p[1]);
 885         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[0], pc->p[1]);
 886         sp_canvas_item_show (pc->c1);
 887         sp_canvas_item_show (pc->cl1);
 888     } else {
 889         sp_canvas_item_hide (pc->c1);
 890         sp_canvas_item_hide (pc->cl1);
 891     }
 892
 893     Geom::Curve const * last_seg = pc->green_curve->last_segment();
 894     if (last_seg) {
 895         Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>( last_seg );
 896         if ( cubic &&
 897              (*cubic)[2] != to_2geom(pc->p[0]) )
 898         {
 899             Geom::Point p2 = (*cubic)[2];
 900             SP_CTRL(pc->c0)->moveto(p2);
 901             sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl0), p2, pc->p[0]);
 902             sp_canvas_item_show (pc->c0);
 903             sp_canvas_item_show (pc->cl0);
 904         } else {
 905             sp_canvas_item_hide (pc->c0);
 906             sp_canvas_item_hide (pc->cl0);
 907         }
 908     }
 909 }
 910
 911 void
 912 pen_lastpoint_move (SPPenContext *const pc, gdouble x, gdouble y)
 913 {
 914     if (pc->npoints != 5)
 915         return;
 916
 917     // green
 918     if (!pc->green_curve->is_empty()) {
 919         pc->green_curve->last_point_additive_move( Geom::Point(x,y) );
 920     } else {
 921         // start anchor too
 922         if (pc->green_anchor) {
 923             pc->green_anchor->dp += Geom::Point(x, y);
 924         }
 925     }
 926
 927     // red
 928     pc->p[0] += Geom::Point(x, y);
 929     pc->p[1] += Geom::Point(x, y);
 930     pen_redraw_all(pc);
 931 }
 932
 933 void
 934 pen_lastpoint_move_screen (SPPenContext *const pc, gdouble x, gdouble y)
 935 {
 936     pen_lastpoint_move (pc, x / pc->desktop->current_zoom(), y / pc->desktop->current_zoom());
 937 }
 938
 939 void
 940 pen_lastpoint_tocurve (SPPenContext *const pc)
 941 {
 942     if (pc->npoints != 5)
 943         return;
 944
 945     Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>( pc->green_curve->last_segment() );
 946     if ( cubic ) {
 947         pc->p[1] = pc->p[0] + (Geom::Point)( (*cubic)[3] - (*cubic)[2] );
 948     } else {
 949         pc->p[1] = pc->p[0] + (1./3)*(pc->p[3] - pc->p[0]);
 950     }
 951
 952     pen_redraw_all(pc);
 953 }
 954
 955 void
 956 pen_lastpoint_toline (SPPenContext *const pc)
 957 {
 958     if (pc->npoints != 5)
 959         return;
 960
 961     pc->p[1] = pc->p[0];
 962
 963     pen_redraw_all(pc);
 964 }
 965
 966
 967 static gint
 968 pen_handle_key_press(SPPenContext *const pc, GdkEvent *event)
 969 {
 970
 971         gint ret = FALSE;
 972     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 973     gdouble const nudge = prefs->getDoubleLimited("/options/nudgedistance/value", 2, 0, 1000); // in px
 974
 975     switch (get_group0_keyval (&event->key)) {
 976
 977         case GDK_Left: // move last point left
 978         case GDK_KP_Left:
 979         case GDK_KP_4:
 980             if (!MOD__CTRL) { // not ctrl
 981                 if (MOD__ALT) { // alt
 982                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, -10, 0); // shift
 983                     else pen_lastpoint_move_screen(pc, -1, 0); // no shift
 984                 }
 985                 else { // no alt
 986                     if (MOD__SHIFT) pen_lastpoint_move(pc, -10*nudge, 0); // shift
 987                     else pen_lastpoint_move(pc, -nudge, 0); // no shift
 988                 }
 989                 ret = TRUE;
 990             }
 991             break;
 992         case GDK_Up: // move last point up
 993         case GDK_KP_Up:
 994         case GDK_KP_8:
 995             if (!MOD__CTRL) { // not ctrl
 996                 if (MOD__ALT) { // alt
 997                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 0, 10); // shift
 998                     else pen_lastpoint_move_screen(pc, 0, 1); // no shift
 999                 }
1000                 else { // no alt
1001                     if (MOD__SHIFT) pen_lastpoint_move(pc, 0, 10*nudge); // shift
1002                     else pen_lastpoint_move(pc, 0, nudge); // no shift
1003                 }
1004                 ret = TRUE;
1005             }
1006             break;
1007         case GDK_Right: // move last point right
1008         case GDK_KP_Right:
1009         case GDK_KP_6:
1010             if (!MOD__CTRL) { // not ctrl
1011                 if (MOD__ALT) { // alt
1012                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 10, 0); // shift
1013                     else pen_lastpoint_move_screen(pc, 1, 0); // no shift
1014                 }
1015                 else { // no alt
1016                     if (MOD__SHIFT) pen_lastpoint_move(pc, 10*nudge, 0); // shift
1017                     else pen_lastpoint_move(pc, nudge, 0); // no shift
1018                 }
1019                 ret = TRUE;
1020             }
1021             break;
1022         case GDK_Down: // move last point down
1023         case GDK_KP_Down:
1024         case GDK_KP_2:
1025             if (!MOD__CTRL) { // not ctrl
1026                 if (MOD__ALT) { // alt
1027                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 0, -10); // shift
1028                     else pen_lastpoint_move_screen(pc, 0, -1); // no shift
1029                 }
1030                 else { // no alt
1031                     if (MOD__SHIFT) pen_lastpoint_move(pc, 0, -10*nudge); // shift
1032                     else pen_lastpoint_move(pc, 0, -nudge); // no shift
1033                 }
1034                 ret = TRUE;
1035             }
1036             break;
1037
1038 /* TODO: this is not yet enabled?? looks like some traces of the Geometry tool
1039         case GDK_P:
1040         case GDK_p:
1041             if (MOD__SHIFT_ONLY) {
1042                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::PARALLEL, 2);
1043                 ret = TRUE;
1044             }
1045             break;
1046
1047         case GDK_C:
1048         case GDK_c:
1049             if (MOD__SHIFT_ONLY) {
1050                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::CIRCLE_3PTS, 3);
1051                 ret = TRUE;
1052             }
1053             break;
1054
1055         case GDK_B:
1056         case GDK_b:
1057             if (MOD__SHIFT_ONLY) {
1058                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::PERP_BISECTOR, 2);
1059                 ret = TRUE;
1060             }
1061             break;
1062
1063         case GDK_A:
1064         case GDK_a:
1065             if (MOD__SHIFT_ONLY) {
1066                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::ANGLE_BISECTOR, 3);
1067                 ret = TRUE;
1068             }
1069             break;
1070 */
1071
1072         case GDK_U:
1073         case GDK_u:
1074             if (MOD__SHIFT_ONLY) {
1075                 pen_lastpoint_tocurve(pc);
1076                 ret = TRUE;
1077             }
1078             break;
1079         case GDK_L:
1080         case GDK_l:
1081             if (MOD__SHIFT_ONLY) {
1082                 pen_lastpoint_toline(pc);
1083                 ret = TRUE;
1084             }
1085             break;
1086
1087         case GDK_Return:
1088         case GDK_KP_Enter:
1089             if (pc->npoints != 0) {
1090                 spdc_pen_finish(pc, FALSE);
1091                 ret = TRUE;
1092             }
1093             break;
1094         case GDK_Escape:
1095             if (pc->npoints != 0) {
1096                 // if drawing, cancel, otherwise pass it up for deselecting
1097                 pen_cancel (pc);
1098                 ret = TRUE;
1099             }
1100             break;
1101         case GDK_z:
1102         case GDK_Z:
1103             if (MOD__CTRL_ONLY && pc->npoints != 0) {
1104                 // if drawing, cancel, otherwise pass it up for undo
1105                 pen_cancel (pc);
1106                 ret = TRUE;
1107             }
1108             break;
1109         case GDK_g:
1110         case GDK_G:
1111             if (MOD__SHIFT_ONLY) {
1112                 sp_selection_to_guides(SP_EVENT_CONTEXT(pc)->desktop);
1113                 ret = true;
1114             }
1115             break;
1116         case GDK_BackSpace:
1117         case GDK_Delete:
1118         case GDK_KP_Delete:
1119             if ( pc->green_curve->is_empty() || (pc->green_curve->last_segment() == NULL) ) {
1120                 if (!pc->red_curve->is_empty()) {
1121                     pen_cancel (pc);
1122                     ret = TRUE;
1123                 } else {
1124                     // do nothing; this event should be handled upstream
1125                 }
1126             } else {
1127                 /* Reset red curve */
1128                 pc->red_curve->reset();
1129                 /* Destroy topmost green bpath */
1130                 if (pc->green_bpaths) {
1131                     if (pc->green_bpaths->data)
1132                         gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
1133                     pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
1134                 }
1135                 /* Get last segment */
1136                 if ( pc->green_curve->is_empty() ) {
1137                     g_warning("pen_handle_key_press, case GDK_KP_Delete: Green curve is empty");
1138                     break;
1139                 }
1140                 // The code below assumes that pc->green_curve has only ONE path !
1141                 Geom::Curve const * crv = pc->green_curve->last_segment();
1142                 pc->p[0] = crv->initialPoint();
1143                 if ( Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>(crv)) {
1144                     pc->p[1] = (*cubic)[1];
1145                 } else {
1146                     pc->p[1] = pc->p[0];
1147                 }
1148                 Geom::Point const pt(( pc->npoints < 4
1149                                      ? (Geom::Point)(crv->finalPoint())
1150                                      : pc->p[3] ));
1151                 pc->npoints = 2;
1152                 pc->green_curve->backspace();
1153                 sp_canvas_item_hide(pc->c0);
1154                 sp_canvas_item_hide(pc->c1);
1155                 sp_canvas_item_hide(pc->cl0);
1156                 sp_canvas_item_hide(pc->cl1);
1157                 pc->state = SP_PEN_CONTEXT_POINT;
1158                 spdc_pen_set_subsequent_point(pc, pt, true);
1159                 ret = TRUE;
1160             }
1161             break;
1162         default:
1163             break;
1164     }
1165     return ret;
1166 }
1167
1168 static void
1169 spdc_reset_colors(SPPenContext *pc)
1170 {
1171     /* Red */
1172     pc->red_curve->reset();
1173     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
1174     /* Blue */
1175     pc->blue_curve->reset();
1176     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->blue_bpath), NULL);
1177     /* Green */
1178     while (pc->green_bpaths) {
1179         gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
1180         pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
1181     }
1182     pc->green_curve->reset();
1183     if (pc->green_anchor) {
1184         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
1185     }
1186     pc->sa = NULL;
1187     pc->ea = NULL;
1188     pc->npoints = 0;
1189     pc->red_curve_is_valid = false;
1190 }
1191
1192
1193 static void
1194 spdc_pen_set_initial_point(SPPenContext *const pc, Geom::Point const p)
1195 {
1196     g_assert( pc->npoints == 0 );
1197
1198     pc->p[0] = p;
1199     pc->p[1] = p;
1200     pc->npoints = 2;
1201     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
1202
1203     sp_canvas_force_full_redraw_after_interruptions(pc->desktop->canvas, 5);
1204 }
1205
1206 /**
1207  * Show the status message for the current line/curve segment.
1208  * This type of message always shows angle/distance as the last
1209  * two parameters ("angle %3.2f&#176;, distance %s").
1210  */
1211 static void
1212 spdc_pen_set_angle_distance_status_message(SPPenContext *const pc, Geom::Point const p, int pc_point_to_compare, gchar const *message)
1213 {
1214     g_assert(pc != NULL);
1215     g_assert((pc_point_to_compare == 0) || (pc_point_to_compare == 3)); // exclude control handles
1216     g_assert(message != NULL);
1217
1218     SPDesktop *desktop = SP_EVENT_CONTEXT(pc)->desktop;
1219     Geom::Point rel = p - pc->p[pc_point_to_compare];
1220     GString *dist = SP_PX_TO_METRIC_STRING(Geom::L2(rel), desktop->namedview->getDefaultMetric());
1221     double angle = atan2(rel[Geom::Y], rel[Geom::X]) * 180 / M_PI;
1222     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
1223     if (prefs->getBool("/options/compassangledisplay/value", 0) != 0)
1224         angle = angle_to_compass (angle);
1225
1226     pc->_message_context->setF(Inkscape::IMMEDIATE_MESSAGE, message, angle, dist->str);
1227     g_string_free(dist, FALSE);
1228 }
1229
1230 static void
1231 spdc_pen_set_subsequent_point(SPPenContext *const pc, Geom::Point const p, bool statusbar, guint status)
1232 {
1233     g_assert( pc->npoints != 0 );
1234     /* todo: Check callers to see whether 2 <= npoints is guaranteed. */
1235
1236     pc->p[2] = p;
1237     pc->p[3] = p;
1238     pc->p[4] = p;
1239     pc->npoints = 5;
1240     pc->red_curve->reset();
1241     bool is_curve;
1242     pc->red_curve->moveto(pc->p[0]);
1243     if (pc->polylines_paraxial && !statusbar) {
1244         // we are drawing horizontal/vertical lines and hit an anchor; draw an L-shaped path
1245         Geom::Point intermed = p;
1246         pen_set_to_nearest_horiz_vert(pc, intermed, status);
1247         pc->red_curve->lineto(intermed);
1248         pc->red_curve->lineto(p);
1249         is_curve = false;
1250     } else {
1251         // one of the 'regular' modes
1252         if (pc->p[1] != pc->p[0])
1253         {
1254             pc->red_curve->curveto(pc->p[1], p, p);
1255             is_curve = true;
1256         } else {
1257             pc->red_curve->lineto(p);
1258             is_curve = false;
1259         }
1260     }
1261
1262     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
1263
1264     if (statusbar) {
1265         gchar *message = is_curve ?
1266             _("<b>Curve segment</b>: angle %3.2f&#176;, distance %s; with <b>Ctrl</b> to snap angle, <b>Enter</b> to finish the path" ):
1267             _("<b>Line segment</b>: angle %3.2f&#176;, distance %s; with <b>Ctrl</b> to snap angle, <b>Enter</b> to finish the path");
1268         spdc_pen_set_angle_distance_status_message(pc, p, 0, message);
1269     }
1270 }
1271
1272 static void
1273 spdc_pen_set_ctrl(SPPenContext *const pc, Geom::Point const p, guint const state)
1274 {
1275     sp_canvas_item_show(pc->c1);
1276     sp_canvas_item_show(pc->cl1);
1277
1278     if ( pc->npoints == 2 ) {
1279         pc->p[1] = p;
1280         sp_canvas_item_hide(pc->c0);
1281         sp_canvas_item_hide(pc->cl0);
1282         SP_CTRL(pc->c1)->moveto(pc->p[1]);
1283         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[0], pc->p[1]);
1284
1285         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"));
1286     } else if ( pc->npoints == 5 ) {
1287         pc->p[4] = p;
1288         sp_canvas_item_show(pc->c0);
1289         sp_canvas_item_show(pc->cl0);
1290         bool is_symm = false;
1291         if ( ( ( pc->mode == SP_PEN_CONTEXT_MODE_CLICK ) && ( state & GDK_CONTROL_MASK ) ) ||
1292              ( ( pc->mode == SP_PEN_CONTEXT_MODE_DRAG ) &&  !( state & GDK_SHIFT_MASK  ) ) ) {
1293             Geom::Point delta = p - pc->p[3];
1294             pc->p[2] = pc->p[3] - delta;
1295             is_symm = true;
1296             pc->red_curve->reset();
1297             pc->red_curve->moveto(pc->p[0]);
1298             pc->red_curve->curveto(pc->p[1], pc->p[2], pc->p[3]);
1299             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
1300         }
1301         SP_CTRL(pc->c0)->moveto(pc->p[2]);
1302         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl0), pc->p[3], pc->p[2]);
1303         SP_CTRL(pc->c1)->moveto(pc->p[4]);
1304         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[3], pc->p[4]);
1305
1306         gchar *message = is_symm ?
1307             _("<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") :
1308             _("<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");
1309         spdc_pen_set_angle_distance_status_message(pc, p, 3, message);
1310     } else {
1311         g_warning("Something bad happened - npoints is %d", pc->npoints);
1312     }
1313 }
1314
1315 static void
1316 spdc_pen_finish_segment(SPPenContext *const pc, Geom::Point const p, guint const state)
1317 {
1318     if (pc->polylines_paraxial) {
1319         pen_last_paraxial_dir = pen_next_paraxial_direction(pc, p, pc->p[0], state);
1320     }
1321     ++pc->num_clicks;
1322
1323     if (!pc->red_curve->is_empty()) {
1324         pc->green_curve->append_continuous(pc->red_curve, 0.0625);
1325         SPCurve *curve = pc->red_curve->copy();
1326         /// \todo fixme:
1327         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), curve);
1328         curve->unref();
1329         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
1330
1331         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
1332
1333         pc->p[0] = pc->p[3];
1334         pc->p[1] = pc->p[4];
1335         pc->npoints = 2;
1336
1337         pc->red_curve->reset();
1338     }
1339 }
1340
1341 static void
1342 spdc_pen_finish(SPPenContext *const pc, gboolean const closed)
1343 {
1344     if (pc->expecting_clicks_for_LPE > 1) {
1345         // don't let the path be finished before we have collected the required number of mouse clicks
1346         return;
1347     }
1348
1349     pc->num_clicks = 0;
1350
1351     pen_disable_events(pc);
1352
1353     SPDesktop *const desktop = pc->desktop;
1354     pc->_message_context->clear();
1355     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Drawing finished"));
1356
1357     pc->red_curve->reset();
1358     spdc_concat_colors_and_flush(pc, closed);
1359     pc->sa = NULL;
1360     pc->ea = NULL;
1361
1362     pc->npoints = 0;
1363     pc->state = SP_PEN_CONTEXT_POINT;
1364
1365     sp_canvas_item_hide(pc->c0);
1366     sp_canvas_item_hide(pc->c1);
1367     sp_canvas_item_hide(pc->cl0);
1368     sp_canvas_item_hide(pc->cl1);
1369
1370     if (pc->green_anchor) {
1371         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
1372     }
1373
1374
1375     sp_canvas_end_forced_full_redraws(pc->desktop->canvas);
1376
1377     pen_enable_events(pc);
1378 }
1379
1380 static void
1381 pen_disable_events(SPPenContext *const pc) {
1382   pc->events_disabled++;
1383 }
1384
1385 static void
1386 pen_enable_events(SPPenContext *const pc) {
1387   g_return_if_fail(pc->events_disabled != 0);
1388
1389   pc->events_disabled--;
1390 }
1391
1392 void
1393 sp_pen_context_wait_for_LPE_mouse_clicks(SPPenContext *pc, Inkscape::LivePathEffect::EffectType effect_type,
1394                                          unsigned int num_clicks, bool use_polylines)
1395 {
1396     if (effect_type == Inkscape::LivePathEffect::INVALID_LPE)
1397         return;
1398
1399     pc->waiting_LPE_type = effect_type;
1400     pc->expecting_clicks_for_LPE = num_clicks;
1401     pc->polylines_only = use_polylines;
1402     pc->polylines_paraxial = false; // TODO: think if this is correct for all cases
1403 }
1404
1405 void
1406 sp_pen_context_cancel_waiting_for_LPE(SPPenContext *pc)
1407 {
1408     pc->waiting_LPE_type = Inkscape::LivePathEffect::INVALID_LPE;
1409     pc->expecting_clicks_for_LPE = 0;
1410     sp_pen_context_set_polyline_mode(pc);
1411 }
1412
1413 static int pen_next_paraxial_direction(const SPPenContext *const pc,
1414                                        Geom::Point const &pt, Geom::Point const &origin, guint state) {
1415     /*
1416      * after the first mouse click we determine whether the mouse pointer is closest to a
1417      * horizontal or vertical segment; for all subsequent mouse clicks, we use the direction
1418      * orthogonal to the last one; pressing Shift toggles the direction
1419      */
1420     if (pc->num_clicks == 0) {
1421         // first mouse click
1422         double dist_h = fabs(pt[Geom::X] - origin[Geom::X]);
1423         double dist_v = fabs(pt[Geom::Y] - origin[Geom::Y]);
1424         int ret = (dist_h < dist_v) ? 1 : 0; // 0 = horizontal, 1 = vertical
1425         pen_last_paraxial_dir = (state & GDK_SHIFT_MASK) ? 1 - ret : ret;
1426         return pen_last_paraxial_dir;
1427     } else {
1428         // subsequent mouse click
1429         return (state & GDK_SHIFT_MASK) ? pen_last_paraxial_dir : 1 - pen_last_paraxial_dir;
1430     }
1431 }
1432
1433 void pen_set_to_nearest_horiz_vert(const SPPenContext *const pc, Geom::Point &pt, guint const state)
1434 {
1435     Geom::Point const &origin = pc->p[0];
1436
1437     int next_dir = pen_next_paraxial_direction(pc, pt, origin, state);
1438
1439     if (next_dir == 0) {
1440         // line is forced to be horizontal
1441         pt[Geom::Y] = origin[Geom::Y];
1442     } else {
1443         // line is forced to be vertical
1444         pt[Geom::X] = origin[Geom::X];
1445     }
1446 }
1447
1448 /*
1449   Local Variables:
1450   mode:c++
1451   c-file-style:"stroustrup"
1452   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1453   indent-tabs-mode:nil
1454   fill-column:99
1455   End:
1456 */
1457 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :