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 "prefs-utils.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, gchar const *key, gchar const *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, NR::Point const p);
  57 static void spdc_pen_set_subsequent_point(SPPenContext *const pc, NR::Point const p, bool statusbar, guint status = 0);
  58 static void spdc_pen_set_ctrl(SPPenContext *pc, NR::Point const p, guint state);
  59 static void spdc_pen_finish_segment(SPPenContext *pc, NR::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 NR::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, NR::Point const &pt, NR::Point const &origin, guint state);
  79 static void pen_set_to_nearest_horiz_vert(const SPPenContext *const pc, NR::Point &pt, guint const state);
  80 static NR::Point pen_get_intermediate_horiz_vert(const SPPenContext *const pc, NR::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     guint mode = prefs_get_int_attribute("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     if (prefs_get_int_attribute("tools.freehand.pen", "selcue", 0) != 0) {
 237         ec->enableSelectionCue();
 238     }
 239 }
 240
 241 static void
 242 pen_cancel (SPPenContext *const pc)
 243 {
 244     pc->num_clicks = 0;
 245     pc->state = SP_PEN_CONTEXT_STOP;
 246     spdc_reset_colors(pc);
 247     sp_canvas_item_hide(pc->c0);
 248     sp_canvas_item_hide(pc->c1);
 249     sp_canvas_item_hide(pc->cl0);
 250     sp_canvas_item_hide(pc->cl1);
 251     pc->_message_context->clear();
 252     pc->_message_context->flash(Inkscape::NORMAL_MESSAGE, _("Drawing cancelled"));
 253
 254     sp_canvas_end_forced_full_redraws(pc->desktop->canvas);
 255 }
 256
 257 /**
 258  * Finalization callback.
 259  */
 260 static void
 261 sp_pen_context_finish(SPEventContext *ec)
 262 {
 263     SPPenContext *pc = SP_PEN_CONTEXT(ec);
 264
 265     if (pc->npoints != 0) {
 266         pen_cancel (pc);
 267     }
 268
 269     if (((SPEventContextClass *) pen_parent_class)->finish) {
 270         ((SPEventContextClass *) pen_parent_class)->finish(ec);
 271     }
 272 }
 273
 274 /**
 275  * Callback that sets key to value in pen context.
 276  */
 277 static void
 278 sp_pen_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 279 {
 280     SPPenContext *pc = SP_PEN_CONTEXT(ec);
 281
 282     if (!strcmp(key, "mode")) {
 283         if ( val && !strcmp(val, "drag") ) {
 284             pc->mode = SP_PEN_CONTEXT_MODE_DRAG;
 285         } else {
 286             pc->mode = SP_PEN_CONTEXT_MODE_CLICK;
 287         }
 288     }
 289 }
 290
 291 /**
 292  * Snaps new node relative to the previous node.
 293  */
 294 static void
 295 spdc_endpoint_snap(SPPenContext const *const pc, NR::Point &p, guint const state)
 296 {
 297     if ((state & GDK_CONTROL_MASK)) { //CTRL enables angular snapping
 298         if (pc->npoints > 0) {
 299             spdc_endpoint_snap_rotation(pc, p, pc->p[0], state);
 300         }
 301     } else {
 302         if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above
 303                                          //After all, the user explicitely asked for angular snapping by
 304                                          //pressing CTRL
 305             spdc_endpoint_snap_free(pc, p, state);
 306         }
 307     }
 308     if (pc->polylines_paraxial) {
 309         // TODO: must we avoid one of the snaps in the previous case distinction in some situations?
 310         pen_set_to_nearest_horiz_vert(pc, p, state);
 311     }
 312 }
 313
 314 /**
 315  * Snaps new node's handle relative to the new node.
 316  */
 317 static void
 318 spdc_endpoint_snap_handle(SPPenContext const *const pc, NR::Point &p, guint const state)
 319 {
 320     g_return_if_fail(( pc->npoints == 2 ||
 321                        pc->npoints == 5   ));
 322
 323     if ((state & GDK_CONTROL_MASK)) { //CTRL enables angular snapping
 324         spdc_endpoint_snap_rotation(pc, p, pc->p[pc->npoints - 2], state);
 325     } else {
 326         if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above
 327             spdc_endpoint_snap_free(pc, p, state);
 328         }
 329     }
 330 }
 331
 332 static gint
 333 sp_pen_context_item_handler(SPEventContext *ec, SPItem *item, GdkEvent *event)
 334 {
 335     SPPenContext *const pc = SP_PEN_CONTEXT(ec);
 336
 337     gint ret = FALSE;
 338
 339     switch (event->type) {
 340         case GDK_BUTTON_PRESS:
 341             ret = pen_handle_button_press(pc, event->button);
 342             break;
 343         case GDK_BUTTON_RELEASE:
 344             ret = pen_handle_button_release(pc, event->button);
 345             break;
 346         default:
 347             break;
 348     }
 349
 350     if (!ret) {
 351         if (((SPEventContextClass *) pen_parent_class)->item_handler)
 352             ret = ((SPEventContextClass *) pen_parent_class)->item_handler(ec, item, event);
 353     }
 354
 355     return ret;
 356 }
 357
 358 /**
 359  * Callback to handle all pen events.
 360  */
 361 static gint
 362 sp_pen_context_root_handler(SPEventContext *ec, GdkEvent *event)
 363 {
 364     g_print ("sp_pen_context_root_handler()\n");
 365     SPPenContext *const pc = SP_PEN_CONTEXT(ec);
 366
 367     gint ret = FALSE;
 368
 369     switch (event->type) {
 370         case GDK_BUTTON_PRESS:
 371             ret = pen_handle_button_press(pc, event->button);
 372             break;
 373
 374         case GDK_MOTION_NOTIFY:
 375             ret = pen_handle_motion_notify(pc, event->motion);
 376             break;
 377
 378         case GDK_BUTTON_RELEASE:
 379             ret = pen_handle_button_release(pc, event->button);
 380             break;
 381
 382         case GDK_2BUTTON_PRESS:
 383             ret = pen_handle_2button_press(pc, event->button);
 384             break;
 385
 386         case GDK_KEY_PRESS:
 387             ret = pen_handle_key_press(pc, event);
 388             break;
 389
 390         default:
 391             break;
 392     }
 393
 394     if (!ret) {
 395         gint (*const parent_root_handler)(SPEventContext *, GdkEvent *)
 396             = ((SPEventContextClass *) pen_parent_class)->root_handler;
 397         if (parent_root_handler) {
 398             ret = parent_root_handler(ec, event);
 399         }
 400     }
 401
 402     return ret;
 403 }
 404
 405 /**
 406  * Handle mouse button press event.
 407  */
 408 static gint pen_handle_button_press(SPPenContext *const pc, GdkEventButton const &bevent)
 409 {
 410     if (pc->events_disabled) {
 411         // skip event processing if events are disabled
 412         return FALSE;
 413     }
 414
 415     SPDrawContext * const dc = SP_DRAW_CONTEXT(pc);
 416     SPDesktop * const desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 417     NR::Point const event_w(bevent.x, bevent.y);
 418     NR::Point const event_dt(desktop->w2d(event_w));
 419     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 420
 421     gint ret = FALSE;
 422     if (bevent.button == 1 && !event_context->space_panning
 423         // make sure this is not the last click for a waiting LPE (otherwise we want to finish the path)
 424         && pc->expecting_clicks_for_LPE != 1) {
 425
 426         if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 427             return TRUE;
 428         }
 429
 430         if (!pc->grab ) {
 431             /* Grab mouse, so release will not pass unnoticed */
 432             pc->grab = SP_CANVAS_ITEM(desktop->acetate);
 433             sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK   |
 434                                             GDK_BUTTON_RELEASE_MASK |
 435                                             GDK_POINTER_MOTION_MASK  ),
 436                                 NULL, bevent.time);
 437         }
 438
 439         pen_drag_origin_w = event_w;
 440         pen_within_tolerance = true;
 441
 442         /* Test whether we hit any anchor. */
 443         SPDrawAnchor * const anchor = spdc_test_inside(pc, event_w);
 444
 445         switch (pc->mode) {
 446             case SP_PEN_CONTEXT_MODE_CLICK:
 447                 /* In click mode we add point on release */
 448                 switch (pc->state) {
 449                     case SP_PEN_CONTEXT_POINT:
 450                     case SP_PEN_CONTEXT_CONTROL:
 451                     case SP_PEN_CONTEXT_CLOSE:
 452                         break;
 453                     case SP_PEN_CONTEXT_STOP:
 454                         /* This is allowed, if we just cancelled curve */
 455                         pc->state = SP_PEN_CONTEXT_POINT;
 456                         break;
 457                     default:
 458                         break;
 459                 }
 460                 break;
 461             case SP_PEN_CONTEXT_MODE_DRAG:
 462                 switch (pc->state) {
 463                     case SP_PEN_CONTEXT_STOP:
 464                         /* This is allowed, if we just cancelled curve */
 465                     case SP_PEN_CONTEXT_POINT:
 466                         if (pc->npoints == 0) {
 467
 468                             if (bevent.state & GDK_CONTROL_MASK) {
 469                                 freehand_create_single_dot(event_context, event_dt, "tools.freehand.pen", bevent.state);
 470                                 ret = TRUE;
 471                                 break;
 472                             }
 473
 474                             // TODO: Perhaps it would be nicer to rearrange the following case
 475                             // distinction so that the case of a waiting LPE is treated separately
 476
 477                             /* Set start anchor */
 478                             pc->sa = anchor;
 479                             NR::Point p;
 480                             if (anchor && !sp_pen_context_has_waiting_LPE(pc)) {
 481                                 /* Adjust point to anchor if needed; if we have a waiting LPE, we need
 482                                    a fresh path to be created so don't continue an existing one */
 483                                 p = anchor->dp;
 484                                 desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Continuing selected path"));
 485                             } else {
 486                                 // This is the first click of a new curve; deselect item so that
 487                                 // this curve is not combined with it (unless it is drawn from its
 488                                 // anchor, which is handled by the sibling branch above)
 489                                 Inkscape::Selection * const selection = sp_desktop_selection(desktop);
 490                                 if (!(bevent.state & GDK_SHIFT_MASK) || sp_pen_context_has_waiting_LPE(pc)) {
 491                                     /* if we have a waiting LPE, we need a fresh path to be created
 492                                        so don't append to an existing one */
 493                                     selection->clear();
 494                                     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Creating new path"));
 495                                 } else if (selection->singleItem() && SP_IS_PATH(selection->singleItem())) {
 496                                     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Appending to selected path"));
 497                                 }
 498
 499                                 /* Create green anchor */
 500                                 p = event_dt;
 501                                 if (!pc->polylines_paraxial) {
 502                                     // only snap the starting point if we're not in horizontal/vertical mode
 503                                     // because otherwise it gets shifted; TODO: why do we snap here at all??
 504                                     spdc_endpoint_snap(pc, p, bevent.state);
 505                                 }
 506                                 pc->green_anchor = sp_draw_anchor_new(pc, pc->green_curve, TRUE, p);
 507                             }
 508                             spdc_pen_set_initial_point(pc, p);
 509                         } else {
 510
 511                             /* Set end anchor */
 512                             pc->ea = anchor;
 513                             NR::Point p;
 514                             if (anchor) {
 515                                 p = anchor->dp;
 516                                 // we hit an anchor, will finish the curve (either with or without closing)
 517                                 // in release handler
 518                                 pc->state = SP_PEN_CONTEXT_CLOSE;
 519
 520                                 if (pc->green_anchor && pc->green_anchor->active) {
 521                                     // we clicked on the current curve start, so close it even if
 522                                     // we drag a handle away from it
 523                                     dc->green_closed = TRUE;
 524                                 }
 525                                 ret = TRUE;
 526                                 break;
 527
 528                             } else {
 529                                 p = event_dt;
 530                                 spdc_endpoint_snap(pc, p, bevent.state); /* Snap node only if not hitting anchor. */
 531                                 spdc_pen_set_subsequent_point(pc, p, true);
 532                                 if (pc->polylines_only) {
 533                                     spdc_pen_finish_segment(pc, p, bevent.state);
 534                                 }
 535                             }
 536                         }
 537
 538                         pc->state = pc->polylines_only ? SP_PEN_CONTEXT_POINT : SP_PEN_CONTEXT_CONTROL;
 539                         ret = TRUE;
 540                         break;
 541                     case SP_PEN_CONTEXT_CONTROL:
 542                         g_warning("Button down in CONTROL state");
 543                         break;
 544                     case SP_PEN_CONTEXT_CLOSE:
 545                         g_warning("Button down in CLOSE state");
 546                         break;
 547                     default:
 548                         break;
 549                 }
 550                 break;
 551             default:
 552                 break;
 553         }
 554     } 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
 555         if (pc->npoints != 0) {
 556
 557             spdc_pen_finish_segment(pc, event_dt, bevent.state);
 558             if (pc->green_closed) {
 559                 // finishing at the start anchor, close curve
 560                 spdc_pen_finish(pc, TRUE);
 561             } else {
 562                 // finishing at some other anchor, finish curve but not close
 563                 spdc_pen_finish(pc, FALSE);
 564             }
 565
 566             ret = TRUE;
 567         }
 568     }
 569
 570     if (pc->expecting_clicks_for_LPE > 0) {
 571         --pc->expecting_clicks_for_LPE;
 572     }
 573
 574     return ret;
 575 }
 576
 577 /**
 578  * Handle motion_notify event.
 579  */
 580 static gint
 581 pen_handle_motion_notify(SPPenContext *const pc, GdkEventMotion const &mevent)
 582 {
 583     gint ret = FALSE;
 584
 585     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 586     SPDesktop * const dt = SP_EVENT_CONTEXT_DESKTOP(event_context);
 587
 588     if (event_context->space_panning || mevent.state & GDK_BUTTON2_MASK || mevent.state & GDK_BUTTON3_MASK) {
 589         // allow scrolling
 590         return FALSE;
 591     }
 592
 593     if (pc->events_disabled) {
 594         // skip motion events if pen events are disabled
 595         return FALSE;
 596     }
 597
 598     NR::Point const event_w(mevent.x,
 599                             mevent.y);
 600     if (pen_within_tolerance) {
 601         gint const tolerance = prefs_get_int_attribute_limited("options.dragtolerance",
 602                                                                "value", 0, 0, 100);
 603         if ( NR::LInfty( event_w - pen_drag_origin_w ) < tolerance ) {
 604             return FALSE;   // Do not drag if we're within tolerance from origin.
 605         }
 606     }
 607     // Once the user has moved farther than tolerance from the original location
 608     // (indicating they intend to move the object, not click), then always process the
 609     // motion notify coordinates as given (no snapping back to origin)
 610     pen_within_tolerance = false;
 611
 612     /* Find desktop coordinates */
 613     NR::Point p = dt->w2d(event_w);
 614
 615     /* Test, whether we hit any anchor */
 616     SPDrawAnchor *anchor = spdc_test_inside(pc, event_w);
 617
 618     switch (pc->mode) {
 619         case SP_PEN_CONTEXT_MODE_CLICK:
 620             switch (pc->state) {
 621                 case SP_PEN_CONTEXT_POINT:
 622                     if ( pc->npoints != 0 ) {
 623                         /* Only set point, if we are already appending */
 624                         spdc_endpoint_snap(pc, p, mevent.state);
 625                         spdc_pen_set_subsequent_point(pc, p, true);
 626                         ret = TRUE;
 627                     }
 628                     break;
 629                 case SP_PEN_CONTEXT_CONTROL:
 630                 case SP_PEN_CONTEXT_CLOSE:
 631                     /* Placing controls is last operation in CLOSE state */
 632                     spdc_endpoint_snap(pc, p, mevent.state);
 633                     spdc_pen_set_ctrl(pc, p, mevent.state);
 634                     ret = TRUE;
 635                     break;
 636                 case SP_PEN_CONTEXT_STOP:
 637                     /* This is perfectly valid */
 638                     break;
 639                 default:
 640                     break;
 641             }
 642             break;
 643         case SP_PEN_CONTEXT_MODE_DRAG:
 644             switch (pc->state) {
 645                 case SP_PEN_CONTEXT_POINT:
 646                     if ( pc->npoints > 0 ) {
 647                         /* Only set point, if we are already appending */
 648
 649                         if (!anchor) {   /* Snap node only if not hitting anchor */
 650                             spdc_endpoint_snap(pc, p, mevent.state);
 651                         }
 652
 653                         spdc_pen_set_subsequent_point(pc, p, !anchor, mevent.state);
 654
 655                         if (anchor && !pc->anchor_statusbar) {
 656                             pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to close and finish the path."));
 657                             pc->anchor_statusbar = true;
 658                         } else if (!anchor && pc->anchor_statusbar) {
 659                             pc->_message_context->clear();
 660                             pc->anchor_statusbar = false;
 661                         }
 662
 663                         ret = TRUE;
 664                     } else {
 665                         if (anchor && !pc->anchor_statusbar) {
 666                             pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to continue the path from this point."));
 667                             pc->anchor_statusbar = true;
 668                         } else if (!anchor && pc->anchor_statusbar) {
 669                             pc->_message_context->clear();
 670                             pc->anchor_statusbar = false;
 671                         }
 672                     }
 673                     break;
 674                 case SP_PEN_CONTEXT_CONTROL:
 675                 case SP_PEN_CONTEXT_CLOSE:
 676                     /* Placing controls is last operation in CLOSE state */
 677
 678                     // snap the handle
 679                     spdc_endpoint_snap_handle(pc, p, mevent.state);
 680
 681                     if (!pc->polylines_only) {
 682                         spdc_pen_set_ctrl(pc, p, mevent.state);
 683                     } else {
 684                         spdc_pen_set_ctrl(pc, pc->p[1], mevent.state);
 685                     }
 686                     gobble_motion_events(GDK_BUTTON1_MASK);
 687                     ret = TRUE;
 688                     break;
 689                 case SP_PEN_CONTEXT_STOP:
 690                     /* This is perfectly valid */
 691                     break;
 692                 default:
 693                     break;
 694             }
 695             break;
 696         default:
 697             break;
 698     }
 699     return ret;
 700 }
 701
 702 /**
 703  * Handle mouse button release event.
 704  */
 705 static gint
 706 pen_handle_button_release(SPPenContext *const pc, GdkEventButton const &revent)
 707 {
 708     if (pc->events_disabled) {
 709         // skip event processing if events are disabled
 710         return FALSE;
 711     }
 712
 713     gint ret = FALSE;
 714     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 715     if ( revent.button == 1  && !event_context->space_panning) {
 716
 717         SPDrawContext *dc = SP_DRAW_CONTEXT (pc);
 718
 719         NR::Point const event_w(revent.x,
 720                                 revent.y);
 721         /* Find desktop coordinates */
 722         NR::Point p = pc->desktop->w2d(event_w);
 723
 724         /* Test whether we hit any anchor. */
 725         SPDrawAnchor *anchor = spdc_test_inside(pc, event_w);
 726
 727         switch (pc->mode) {
 728             case SP_PEN_CONTEXT_MODE_CLICK:
 729                 switch (pc->state) {
 730                     case SP_PEN_CONTEXT_POINT:
 731                         if ( pc->npoints == 0 ) {
 732                             /* Start new thread only with button release */
 733                             if (anchor) {
 734                                 p = anchor->dp;
 735                             }
 736                             pc->sa = anchor;
 737                             spdc_pen_set_initial_point(pc, p);
 738                         } else {
 739                             /* Set end anchor here */
 740                             pc->ea = anchor;
 741                             if (anchor) {
 742                                 p = anchor->dp;
 743                             }
 744                         }
 745                         pc->state = SP_PEN_CONTEXT_CONTROL;
 746                         ret = TRUE;
 747                         break;
 748                     case SP_PEN_CONTEXT_CONTROL:
 749                         /* End current segment */
 750                         spdc_endpoint_snap(pc, p, revent.state);
 751                         spdc_pen_finish_segment(pc, p, revent.state);
 752                         pc->state = SP_PEN_CONTEXT_POINT;
 753                         ret = TRUE;
 754                         break;
 755                     case SP_PEN_CONTEXT_CLOSE:
 756                         /* End current segment */
 757                         if (!anchor) {   /* Snap node only if not hitting anchor */
 758                             spdc_endpoint_snap(pc, p, revent.state);
 759                         }
 760                         spdc_pen_finish_segment(pc, p, revent.state);
 761                         spdc_pen_finish(pc, TRUE);
 762                         pc->state = SP_PEN_CONTEXT_POINT;
 763                         ret = TRUE;
 764                         break;
 765                     case SP_PEN_CONTEXT_STOP:
 766                         /* This is allowed, if we just cancelled curve */
 767                         pc->state = SP_PEN_CONTEXT_POINT;
 768                         ret = TRUE;
 769                         break;
 770                     default:
 771                         break;
 772                 }
 773                 break;
 774             case SP_PEN_CONTEXT_MODE_DRAG:
 775                 switch (pc->state) {
 776                     case SP_PEN_CONTEXT_POINT:
 777                     case SP_PEN_CONTEXT_CONTROL:
 778                         if (!pc->polylines_only) {
 779                             spdc_endpoint_snap(pc, p, revent.state);
 780                             spdc_pen_finish_segment(pc, p, revent.state);
 781                         }
 782                         break;
 783                     case SP_PEN_CONTEXT_CLOSE:
 784                         spdc_endpoint_snap(pc, p, revent.state);
 785                         spdc_pen_finish_segment(pc, p, revent.state);
 786                         if (pc->green_closed) {
 787                             // finishing at the start anchor, close curve
 788                             spdc_pen_finish(pc, TRUE);
 789                         } else {
 790                             // finishing at some other anchor, finish curve but not close
 791                             spdc_pen_finish(pc, FALSE);
 792                         }
 793                         break;
 794                     case SP_PEN_CONTEXT_STOP:
 795                         /* This is allowed, if we just cancelled curve */
 796                         break;
 797                     default:
 798                         break;
 799                 }
 800                 pc->state = SP_PEN_CONTEXT_POINT;
 801                 ret = TRUE;
 802                 break;
 803             default:
 804                 break;
 805         }
 806
 807         if (pc->grab) {
 808             /* Release grab now */
 809             sp_canvas_item_ungrab(pc->grab, revent.time);
 810             pc->grab = NULL;
 811         }
 812
 813         ret = TRUE;
 814
 815         dc->green_closed = FALSE;
 816     }
 817
 818     // TODO: can we be sure that the path was created correctly?
 819     // TODO: should we offer an option to collect the clicks in a list?
 820     if (pc->expecting_clicks_for_LPE == 0 && sp_pen_context_has_waiting_LPE(pc)) {
 821         sp_pen_context_set_polyline_mode(pc);
 822
 823         SPEventContext *ec = SP_EVENT_CONTEXT(pc);
 824         Inkscape::Selection *selection = sp_desktop_selection (ec->desktop);
 825
 826         if (pc->waiting_LPE) {
 827             // we have an already created LPE waiting for a path
 828             pc->waiting_LPE->acceptParamPath(SP_PATH(selection->singleItem()));
 829             selection->add(SP_OBJECT(pc->waiting_item));
 830             pc->waiting_LPE = NULL;
 831         } else {
 832             // the case that we need to create a new LPE and apply it to the just-drawn path is
 833             // handled in spdc_check_for_and_apply_waiting_LPE() in draw-context.cpp
 834         }
 835     }
 836
 837     return ret;
 838 }
 839
 840 static gint
 841 pen_handle_2button_press(SPPenContext *const pc, GdkEventButton const &bevent)
 842 {
 843     gint ret = FALSE;
 844     if (pc->npoints != 0 && bevent.button != 2) {
 845         spdc_pen_finish(pc, FALSE);
 846         ret = TRUE;
 847     }
 848     return ret;
 849 }
 850
 851 void
 852 pen_redraw_all (SPPenContext *const pc)
 853 {
 854     // green
 855     if (pc->green_bpaths) {
 856         // remove old piecewise green canvasitems
 857         while (pc->green_bpaths) {
 858             gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
 859             pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
 860         }
 861         // one canvas bpath for all of green_curve
 862         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), pc->green_curve);
 863         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 864         sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cshape), 0, SP_WIND_RULE_NONZERO);
 865
 866         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
 867     }
 868
 869     if (pc->green_anchor)
 870         SP_CTRL(pc->green_anchor->ctrl)->moveto(pc->green_anchor->dp);
 871
 872     pc->red_curve->reset();
 873     pc->red_curve->moveto(pc->p[0]);
 874     pc->red_curve->curveto(pc->p[1], pc->p[2], pc->p[3]);
 875     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 876
 877     // handles
 878     if (pc->p[0] != pc->p[1]) {
 879         SP_CTRL(pc->c1)->moveto(pc->p[1]);
 880         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[0], pc->p[1]);
 881         sp_canvas_item_show (pc->c1);
 882         sp_canvas_item_show (pc->cl1);
 883     } else {
 884         sp_canvas_item_hide (pc->c1);
 885         sp_canvas_item_hide (pc->cl1);
 886     }
 887
 888     Geom::Curve const * last_seg = pc->green_curve->last_segment();
 889     if (last_seg) {
 890         Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>( last_seg );
 891         if ( cubic &&
 892              (*cubic)[2] != to_2geom(pc->p[0]) )
 893         {
 894             NR::Point p2 = (*cubic)[2];
 895             SP_CTRL(pc->c0)->moveto(p2);
 896             sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl0), p2, pc->p[0]);
 897             sp_canvas_item_show (pc->c0);
 898             sp_canvas_item_show (pc->cl0);
 899         } else {
 900             sp_canvas_item_hide (pc->c0);
 901             sp_canvas_item_hide (pc->cl0);
 902         }
 903     }
 904 }
 905
 906 void
 907 pen_lastpoint_move (SPPenContext *const pc, gdouble x, gdouble y)
 908 {
 909     if (pc->npoints != 5)
 910         return;
 911
 912     // green
 913     if (!pc->green_curve->is_empty()) {
 914         pc->green_curve->last_point_additive_move( Geom::Point(x,y) );
 915     } else {
 916         // start anchor too
 917         if (pc->green_anchor) {
 918             pc->green_anchor->dp += NR::Point(x, y);
 919         }
 920     }
 921
 922     // red
 923     pc->p[0] += NR::Point(x, y);
 924     pc->p[1] += NR::Point(x, y);
 925     pen_redraw_all(pc);
 926 }
 927
 928 void
 929 pen_lastpoint_move_screen (SPPenContext *const pc, gdouble x, gdouble y)
 930 {
 931     pen_lastpoint_move (pc, x / pc->desktop->current_zoom(), y / pc->desktop->current_zoom());
 932 }
 933
 934 void
 935 pen_lastpoint_tocurve (SPPenContext *const pc)
 936 {
 937     if (pc->npoints != 5)
 938         return;
 939
 940     Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>( pc->green_curve->last_segment() );
 941     if ( cubic ) {
 942         pc->p[1] = pc->p[0] + (NR::Point)( (*cubic)[3] - (*cubic)[2] );
 943     } else {
 944         pc->p[1] = pc->p[0] + (1./3)*(pc->p[3] - pc->p[0]);
 945     }
 946
 947     pen_redraw_all(pc);
 948 }
 949
 950 void
 951 pen_lastpoint_toline (SPPenContext *const pc)
 952 {
 953     if (pc->npoints != 5)
 954         return;
 955
 956     pc->p[1] = pc->p[0];
 957
 958     pen_redraw_all(pc);
 959 }
 960
 961
 962 static gint
 963 pen_handle_key_press(SPPenContext *const pc, GdkEvent *event)
 964 {
 965     gint ret = FALSE;
 966     gdouble const nudge = prefs_get_double_attribute_limited("options.nudgedistance", "value", 2, 0, 1000); // in px
 967
 968     switch (get_group0_keyval (&event->key)) {
 969
 970         case GDK_Left: // move last point left
 971         case GDK_KP_Left:
 972         case GDK_KP_4:
 973             if (!MOD__CTRL) { // not ctrl
 974                 if (MOD__ALT) { // alt
 975                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, -10, 0); // shift
 976                     else pen_lastpoint_move_screen(pc, -1, 0); // no shift
 977                 }
 978                 else { // no alt
 979                     if (MOD__SHIFT) pen_lastpoint_move(pc, -10*nudge, 0); // shift
 980                     else pen_lastpoint_move(pc, -nudge, 0); // no shift
 981                 }
 982                 ret = TRUE;
 983             }
 984             break;
 985         case GDK_Up: // move last point up
 986         case GDK_KP_Up:
 987         case GDK_KP_8:
 988             if (!MOD__CTRL) { // not ctrl
 989                 if (MOD__ALT) { // alt
 990                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 0, 10); // shift
 991                     else pen_lastpoint_move_screen(pc, 0, 1); // no shift
 992                 }
 993                 else { // no alt
 994                     if (MOD__SHIFT) pen_lastpoint_move(pc, 0, 10*nudge); // shift
 995                     else pen_lastpoint_move(pc, 0, nudge); // no shift
 996                 }
 997                 ret = TRUE;
 998             }
 999             break;
1000         case GDK_Right: // move last point right
1001         case GDK_KP_Right:
1002         case GDK_KP_6:
1003             if (!MOD__CTRL) { // not ctrl
1004                 if (MOD__ALT) { // alt
1005                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 10, 0); // shift
1006                     else pen_lastpoint_move_screen(pc, 1, 0); // no shift
1007                 }
1008                 else { // no alt
1009                     if (MOD__SHIFT) pen_lastpoint_move(pc, 10*nudge, 0); // shift
1010                     else pen_lastpoint_move(pc, nudge, 0); // no shift
1011                 }
1012                 ret = TRUE;
1013             }
1014             break;
1015         case GDK_Down: // move last point down
1016         case GDK_KP_Down:
1017         case GDK_KP_2:
1018             if (!MOD__CTRL) { // not ctrl
1019                 if (MOD__ALT) { // alt
1020                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 0, -10); // shift
1021                     else pen_lastpoint_move_screen(pc, 0, -1); // no shift
1022                 }
1023                 else { // no alt
1024                     if (MOD__SHIFT) pen_lastpoint_move(pc, 0, -10*nudge); // shift
1025                     else pen_lastpoint_move(pc, 0, -nudge); // no shift
1026                 }
1027                 ret = TRUE;
1028             }
1029             break;
1030
1031         case GDK_P:
1032         case GDK_p:
1033             if (MOD__SHIFT_ONLY) {
1034                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::PARALLEL, 2);
1035                 ret = TRUE;
1036             }
1037             break;
1038
1039         case GDK_C:
1040         case GDK_c:
1041             if (MOD__SHIFT_ONLY) {
1042                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::CIRCLE_3PTS, 3);
1043                 ret = TRUE;
1044             }
1045             break;
1046
1047         case GDK_B:
1048         case GDK_b:
1049             if (MOD__SHIFT_ONLY) {
1050                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::PERP_BISECTOR, 2);
1051                 ret = TRUE;
1052             }
1053             break;
1054
1055         case GDK_A:
1056         case GDK_a:
1057             if (MOD__SHIFT_ONLY) {
1058                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::ANGLE_BISECTOR, 3);
1059                 ret = TRUE;
1060             }
1061             break;
1062
1063         case GDK_U:
1064         case GDK_u:
1065             if (MOD__SHIFT_ONLY) {
1066                 pen_lastpoint_tocurve(pc);
1067                 ret = TRUE;
1068             }
1069             break;
1070         case GDK_L:
1071         case GDK_l:
1072             if (MOD__SHIFT_ONLY) {
1073                 pen_lastpoint_toline(pc);
1074                 ret = TRUE;
1075             }
1076             break;
1077
1078         case GDK_Return:
1079         case GDK_KP_Enter:
1080             if (pc->npoints != 0) {
1081                 spdc_pen_finish(pc, FALSE);
1082                 ret = TRUE;
1083             }
1084             break;
1085         case GDK_Escape:
1086             if (pc->npoints != 0) {
1087                 // if drawing, cancel, otherwise pass it up for deselecting
1088                 pen_cancel (pc);
1089                 ret = TRUE;
1090             }
1091             break;
1092         case GDK_z:
1093         case GDK_Z:
1094             if (MOD__CTRL_ONLY && pc->npoints != 0) {
1095                 // if drawing, cancel, otherwise pass it up for undo
1096                 pen_cancel (pc);
1097                 ret = TRUE;
1098             }
1099             break;
1100         case GDK_g:
1101         case GDK_G:
1102             if (MOD__SHIFT_ONLY) {
1103                 sp_selection_to_guides(SP_EVENT_CONTEXT(pc)->desktop);
1104                 ret = true;
1105             }
1106             break;
1107         case GDK_BackSpace:
1108         case GDK_Delete:
1109         case GDK_KP_Delete:
1110             if (pc->green_curve->is_empty()) {
1111                 if (!pc->red_curve->is_empty()) {
1112                     pen_cancel (pc);
1113                     ret = TRUE;
1114                 } else {
1115                     // do nothing; this event should be handled upstream
1116                 }
1117             } else {
1118                 /* Reset red curve */
1119                 pc->red_curve->reset();
1120                 /* Destroy topmost green bpath */
1121                 if (pc->green_bpaths) {
1122                     if (pc->green_bpaths->data)
1123                         gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
1124                     pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
1125                 }
1126                 /* Get last segment */
1127                 if ( pc->green_curve->is_empty() ) {
1128                     g_warning("pen_handle_key_press, case GDK_KP_Delete: Green curve is empty");
1129                     break;
1130                 }
1131                 // The code below assumes that pc->green_curve has only ONE path !
1132                 Geom::Path const & path = pc->green_curve->get_pathvector().back();
1133                 Geom::Curve const * crv = &path.back_default();
1134                 pc->p[0] = crv->initialPoint();
1135                 if ( Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>(crv)) {
1136                     pc->p[1] = (*cubic)[1];
1137                 } else {
1138                     pc->p[1] = pc->p[0];
1139                 }
1140                 NR::Point const pt(( pc->npoints < 4
1141                                      ? (NR::Point)(crv->finalPoint())
1142                                      : pc->p[3] ));
1143                 pc->npoints = 2;
1144                 pc->green_curve->backspace();
1145                 sp_canvas_item_hide(pc->c0);
1146                 sp_canvas_item_hide(pc->c1);
1147                 sp_canvas_item_hide(pc->cl0);
1148                 sp_canvas_item_hide(pc->cl1);
1149                 pc->state = SP_PEN_CONTEXT_POINT;
1150                 spdc_pen_set_subsequent_point(pc, pt, true);
1151                 ret = TRUE;
1152             }
1153             break;
1154         default:
1155             break;
1156     }
1157     return ret;
1158 }
1159
1160 static void
1161 spdc_reset_colors(SPPenContext *pc)
1162 {
1163     /* Red */
1164     pc->red_curve->reset();
1165     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
1166     /* Blue */
1167     pc->blue_curve->reset();
1168     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->blue_bpath), NULL);
1169     /* Green */
1170     while (pc->green_bpaths) {
1171         gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
1172         pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
1173     }
1174     pc->green_curve->reset();
1175     if (pc->green_anchor) {
1176         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
1177     }
1178     pc->sa = NULL;
1179     pc->ea = NULL;
1180     pc->npoints = 0;
1181     pc->red_curve_is_valid = false;
1182 }
1183
1184
1185 static void
1186 spdc_pen_set_initial_point(SPPenContext *const pc, NR::Point const p)
1187 {
1188     g_assert( pc->npoints == 0 );
1189
1190     pc->p[0] = p;
1191     pc->p[1] = p;
1192     pc->npoints = 2;
1193     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
1194
1195     sp_canvas_force_full_redraw_after_interruptions(pc->desktop->canvas, 5);
1196 }
1197
1198 /**
1199  * Show the status message for the current line/curve segment.
1200  * This type of message always shows angle/distance as the last
1201  * two parameters ("angle %3.2f&#176;, distance %s").
1202  */
1203 static void
1204 spdc_pen_set_angle_distance_status_message(SPPenContext *const pc, NR::Point const p, int pc_point_to_compare, gchar const *message)
1205 {
1206     g_assert(pc != NULL);
1207     g_assert((pc_point_to_compare == 0) || (pc_point_to_compare == 3)); // exclude control handles
1208     g_assert(message != NULL);
1209
1210     SPDesktop *desktop = SP_EVENT_CONTEXT(pc)->desktop;
1211     NR::Point rel = p - pc->p[pc_point_to_compare];
1212     GString *dist = SP_PX_TO_METRIC_STRING(NR::L2(rel), desktop->namedview->getDefaultMetric());
1213     double angle = atan2(rel[NR::Y], rel[NR::X]) * 180 / M_PI;
1214     if (prefs_get_int_attribute("options.compassangledisplay", "value", 0) != 0)
1215         angle = angle_to_compass (angle);
1216
1217     pc->_message_context->setF(Inkscape::IMMEDIATE_MESSAGE, message, angle, dist->str);
1218     g_string_free(dist, FALSE);
1219 }
1220
1221 static void
1222 spdc_pen_set_subsequent_point(SPPenContext *const pc, NR::Point const p, bool statusbar, guint status)
1223 {
1224     g_assert( pc->npoints != 0 );
1225     /* todo: Check callers to see whether 2 <= npoints is guaranteed. */
1226
1227     pc->p[2] = p;
1228     pc->p[3] = p;
1229     pc->p[4] = p;
1230     pc->npoints = 5;
1231     pc->red_curve->reset();
1232     bool is_curve;
1233     pc->red_curve->moveto(pc->p[0]);
1234     if (pc->polylines_paraxial && !statusbar) {
1235         // we are drawing horizontal/vertical lines and hit an anchor; draw an L-shaped path
1236         NR::Point intermed = p;
1237         pen_set_to_nearest_horiz_vert(pc, intermed, status);
1238         pc->red_curve->lineto(intermed);
1239         pc->red_curve->lineto(p);
1240         is_curve = false;
1241     } else {
1242         // one of the 'regular' modes
1243         if (pc->p[1] != pc->p[0])
1244         {
1245             pc->red_curve->curveto(pc->p[1], p, p);
1246             is_curve = true;
1247         } else {
1248             pc->red_curve->lineto(p);
1249             is_curve = false;
1250         }
1251     }
1252
1253     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
1254
1255     if (statusbar) {
1256         gchar *message = is_curve ?
1257             _("<b>Curve segment</b>: angle %3.2f&#176;, distance %s; with <b>Ctrl</b> to snap angle, <b>Enter</b> to finish the path" ):
1258             _("<b>Line segment</b>: angle %3.2f&#176;, distance %s; with <b>Ctrl</b> to snap angle, <b>Enter</b> to finish the path");
1259         spdc_pen_set_angle_distance_status_message(pc, p, 0, message);
1260     }
1261 }
1262
1263 static void
1264 spdc_pen_set_ctrl(SPPenContext *const pc, NR::Point const p, guint const state)
1265 {
1266     sp_canvas_item_show(pc->c1);
1267     sp_canvas_item_show(pc->cl1);
1268
1269     if ( pc->npoints == 2 ) {
1270         pc->p[1] = p;
1271         sp_canvas_item_hide(pc->c0);
1272         sp_canvas_item_hide(pc->cl0);
1273         SP_CTRL(pc->c1)->moveto(pc->p[1]);
1274         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[0], pc->p[1]);
1275
1276         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"));
1277     } else if ( pc->npoints == 5 ) {
1278         pc->p[4] = p;
1279         sp_canvas_item_show(pc->c0);
1280         sp_canvas_item_show(pc->cl0);
1281         bool is_symm = false;
1282         if ( ( ( pc->mode == SP_PEN_CONTEXT_MODE_CLICK ) && ( state & GDK_CONTROL_MASK ) ) ||
1283              ( ( pc->mode == SP_PEN_CONTEXT_MODE_DRAG ) &&  !( state & GDK_SHIFT_MASK  ) ) ) {
1284             NR::Point delta = p - pc->p[3];
1285             pc->p[2] = pc->p[3] - delta;
1286             is_symm = true;
1287             pc->red_curve->reset();
1288             pc->red_curve->moveto(pc->p[0]);
1289             pc->red_curve->curveto(pc->p[1], pc->p[2], pc->p[3]);
1290             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
1291         }
1292         SP_CTRL(pc->c0)->moveto(pc->p[2]);
1293         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl0), pc->p[3], pc->p[2]);
1294         SP_CTRL(pc->c1)->moveto(pc->p[4]);
1295         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[3], pc->p[4]);
1296
1297         gchar *message = is_symm ?
1298             _("<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") :
1299             _("<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");
1300         spdc_pen_set_angle_distance_status_message(pc, p, 3, message);
1301     } else {
1302         g_warning("Something bad happened - npoints is %d", pc->npoints);
1303     }
1304 }
1305
1306 static void
1307 spdc_pen_finish_segment(SPPenContext *const pc, NR::Point const p, guint const state)
1308 {
1309     if (pc->polylines_paraxial) {
1310         pen_last_paraxial_dir = pen_next_paraxial_direction(pc, p, pc->p[0], state);
1311     }
1312     ++pc->num_clicks;
1313
1314     if (!pc->red_curve->is_empty()) {
1315         pc->green_curve->append_continuous(pc->red_curve, 0.0625);
1316         SPCurve *curve = pc->red_curve->copy();
1317         /// \todo fixme:
1318         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), curve);
1319         curve->unref();
1320         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
1321
1322         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
1323
1324         pc->p[0] = pc->p[3];
1325         pc->p[1] = pc->p[4];
1326         pc->npoints = 2;
1327
1328         pc->red_curve->reset();
1329     }
1330 }
1331
1332 static void
1333 spdc_pen_finish(SPPenContext *const pc, gboolean const closed)
1334 {
1335     if (pc->expecting_clicks_for_LPE > 1) {
1336         // don't let the path be finished before we have collected the required number of mouse clicks
1337         return;
1338     }
1339
1340     pc->num_clicks = 0;
1341
1342     pen_disable_events(pc);
1343
1344     SPDesktop *const desktop = pc->desktop;
1345     pc->_message_context->clear();
1346     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Drawing finished"));
1347
1348     pc->red_curve->reset();
1349     spdc_concat_colors_and_flush(pc, closed);
1350     pc->sa = NULL;
1351     pc->ea = NULL;
1352
1353     pc->npoints = 0;
1354     pc->state = SP_PEN_CONTEXT_POINT;
1355
1356     sp_canvas_item_hide(pc->c0);
1357     sp_canvas_item_hide(pc->c1);
1358     sp_canvas_item_hide(pc->cl0);
1359     sp_canvas_item_hide(pc->cl1);
1360
1361     if (pc->green_anchor) {
1362         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
1363     }
1364
1365
1366     sp_canvas_end_forced_full_redraws(pc->desktop->canvas);
1367
1368     pen_enable_events(pc);
1369 }
1370
1371 static void
1372 pen_disable_events(SPPenContext *const pc) {
1373   pc->events_disabled++;
1374 }
1375
1376 static void
1377 pen_enable_events(SPPenContext *const pc) {
1378   g_return_if_fail(pc->events_disabled != 0);
1379
1380   pc->events_disabled--;
1381 }
1382
1383 void
1384 sp_pen_context_wait_for_LPE_mouse_clicks(SPPenContext *pc, Inkscape::LivePathEffect::EffectType effect_type,
1385                                          unsigned int num_clicks, bool use_polylines)
1386 {
1387     if (effect_type == Inkscape::LivePathEffect::INVALID_LPE)
1388         return;
1389
1390     g_print ("Now waiting for %s to be applied\n",
1391              Inkscape::LivePathEffect::LPETypeConverter.get_label(effect_type).c_str());
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     g_print ("Cancelled waiting for mouse clicks for %s\n",
1403              Inkscape::LivePathEffect::LPETypeConverter.get_label(pc->waiting_LPE_type).c_str());
1404
1405     pc->waiting_LPE_type = Inkscape::LivePathEffect::INVALID_LPE;
1406     pc->expecting_clicks_for_LPE = 0;
1407     sp_pen_context_set_polyline_mode(pc);
1408 }
1409
1410 static int pen_next_paraxial_direction(const SPPenContext *const pc,
1411                                        NR::Point const &pt, NR::Point const &origin, guint state) {
1412     /*
1413      * after the first mouse click we determine whether the mouse pointer is closest to a
1414      * horizontal or vertical segment; for all subsequent mouse clicks, we use the direction
1415      * orthogonal to the last one; pressing Shift toggles the direction
1416      */
1417     if (pc->num_clicks == 0) {
1418         // first mouse click
1419         double dist_h = fabs(pt[NR::X] - origin[NR::X]);
1420         double dist_v = fabs(pt[NR::Y] - origin[NR::Y]);
1421         int ret = (dist_h < dist_v) ? 1 : 0; // 0 = horizontal, 1 = vertical
1422         pen_last_paraxial_dir = (state & GDK_SHIFT_MASK) ? 1 - ret : ret;
1423         return pen_last_paraxial_dir;
1424     } else {
1425         // subsequent mouse click
1426         return (state & GDK_SHIFT_MASK) ? pen_last_paraxial_dir : 1 - pen_last_paraxial_dir;
1427     }
1428 }
1429
1430 void pen_set_to_nearest_horiz_vert(const SPPenContext *const pc, NR::Point &pt, guint const state)
1431 {
1432     NR::Point const &origin = pc->p[0];
1433
1434     int next_dir = pen_next_paraxial_direction(pc, pt, origin, state);
1435
1436     if (next_dir == 0) {
1437         // line is forced to be horizontal
1438         pt[NR::Y] = origin[NR::Y];
1439     } else {
1440         // line is forced to be vertical
1441         pt[NR::X] = origin[NR::X];
1442     }
1443 }
1444
1445 NR::Point pen_get_intermediate_horiz_vert(const SPPenContext *const pc, NR::Point const &pt)
1446 {
1447     NR::Point const &origin = pc->p[0];
1448
1449     if (pen_last_paraxial_dir == 0) {
1450         return NR::Point (origin[NR::X], pt[NR::Y]);
1451     } else {
1452         return NR::Point (pt[NR::X], origin[NR::Y]);
1453     }
1454 }
1455
1456 /*
1457   Local Variables:
1458   mode:c++
1459   c-file-style:"stroustrup"
1460   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1461   indent-tabs-mode:nil
1462   fill-column:99
1463   End:
1464 */
1465 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :