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
  45 static void sp_pen_context_class_init(SPPenContextClass *klass);
  46 static void sp_pen_context_init(SPPenContext *pc);
  47 static void sp_pen_context_dispose(GObject *object);
  48
  49 static void sp_pen_context_setup(SPEventContext *ec);
  50 static void sp_pen_context_finish(SPEventContext *ec);
  51 static void sp_pen_context_set(SPEventContext *ec, gchar const *key, gchar const *val);
  52 static gint sp_pen_context_root_handler(SPEventContext *ec, GdkEvent *event);
  53 static gint sp_pen_context_item_handler(SPEventContext *event_context, SPItem *item, GdkEvent *event);
  54
  55 static void spdc_pen_set_initial_point(SPPenContext *pc, NR::Point const p);
  56 static void spdc_pen_set_subsequent_point(SPPenContext *const pc, NR::Point const p, bool statusbar, guint status = 0);
  57 static void spdc_pen_set_ctrl(SPPenContext *pc, NR::Point const p, guint state);
  58 static void spdc_pen_finish_segment(SPPenContext *pc, NR::Point p, guint state);
  59
  60 static void spdc_pen_finish(SPPenContext *pc, gboolean closed);
  61
  62 static gint pen_handle_button_press(SPPenContext *const pc, GdkEventButton const &bevent);
  63 static gint pen_handle_motion_notify(SPPenContext *const pc, GdkEventMotion const &mevent);
  64 static gint pen_handle_button_release(SPPenContext *const pc, GdkEventButton const &revent);
  65 static gint pen_handle_2button_press(SPPenContext *const pc, GdkEventButton const &bevent);
  66 static gint pen_handle_key_press(SPPenContext *const pc, GdkEvent *event);
  67 static void spdc_reset_colors(SPPenContext *pc);
  68
  69 static void pen_disable_events(SPPenContext *const pc);
  70 static void pen_enable_events(SPPenContext *const pc);
  71
  72 static NR::Point pen_drag_origin_w(0, 0);
  73 static bool pen_within_tolerance = false;
  74
  75 static SPDrawContextClass *pen_parent_class;
  76
  77 static int pen_next_paraxial_direction(const SPPenContext *const pc, NR::Point const &pt, NR::Point const &origin, guint state);
  78 static void pen_set_to_nearest_horiz_vert(const SPPenContext *const pc, NR::Point &pt, guint const state);
  79 static NR::Point pen_get_intermediate_horiz_vert(const SPPenContext *const pc, NR::Point const &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     guint mode = prefs_get_int_attribute("tools.freehand.pen", "freehand-mode", 0);
 196     pc->polylines_only = (mode == 2 || mode == 3);
 197     pc->polylines_paraxial = (mode == 3);
 198 }
 199
 200 /**
 201  * Callback to initialize SPPenContext object.
 202  */
 203 static void
 204 sp_pen_context_setup(SPEventContext *ec)
 205 {
 206     SPPenContext *pc;
 207
 208     pc = SP_PEN_CONTEXT(ec);
 209
 210     if (((SPEventContextClass *) pen_parent_class)->setup) {
 211         ((SPEventContextClass *) pen_parent_class)->setup(ec);
 212     }
 213
 214     /* Pen indicators */
 215     pc->c0 = sp_canvas_item_new(sp_desktop_controls(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRL, "shape", SP_CTRL_SHAPE_CIRCLE,
 216                                 "size", 4.0, "filled", 0, "fill_color", 0xff00007f, "stroked", 1, "stroke_color", 0x0000ff7f, NULL);
 217     pc->c1 = sp_canvas_item_new(sp_desktop_controls(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRL, "shape", SP_CTRL_SHAPE_CIRCLE,
 218                                 "size", 4.0, "filled", 0, "fill_color", 0xff00007f, "stroked", 1, "stroke_color", 0x0000ff7f, NULL);
 219     pc->cl0 = sp_canvas_item_new(sp_desktop_controls(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRLLINE, NULL);
 220     sp_ctrlline_set_rgba32(SP_CTRLLINE(pc->cl0), 0x0000007f);
 221     pc->cl1 = sp_canvas_item_new(sp_desktop_controls(SP_EVENT_CONTEXT_DESKTOP(ec)), SP_TYPE_CTRLLINE, NULL);
 222     sp_ctrlline_set_rgba32(SP_CTRLLINE(pc->cl1), 0x0000007f);
 223
 224     sp_canvas_item_hide(pc->c0);
 225     sp_canvas_item_hide(pc->c1);
 226     sp_canvas_item_hide(pc->cl0);
 227     sp_canvas_item_hide(pc->cl1);
 228
 229     sp_event_context_read(ec, "mode");
 230
 231     pc->anchor_statusbar = false;
 232
 233     sp_pen_context_set_polyline_mode(pc);
 234
 235     if (prefs_get_int_attribute("tools.freehand.pen", "selcue", 0) != 0) {
 236         ec->enableSelectionCue();
 237     }
 238 }
 239
 240 static void
 241 pen_cancel (SPPenContext *const pc)
 242 {
 243     pc->num_clicks = 0;
 244     pc->state = SP_PEN_CONTEXT_STOP;
 245     spdc_reset_colors(pc);
 246     sp_canvas_item_hide(pc->c0);
 247     sp_canvas_item_hide(pc->c1);
 248     sp_canvas_item_hide(pc->cl0);
 249     sp_canvas_item_hide(pc->cl1);
 250     pc->_message_context->clear();
 251     pc->_message_context->flash(Inkscape::NORMAL_MESSAGE, _("Drawing cancelled"));
 252
 253     sp_canvas_end_forced_full_redraws(pc->desktop->canvas);
 254 }
 255
 256 /**
 257  * Finalization callback.
 258  */
 259 static void
 260 sp_pen_context_finish(SPEventContext *ec)
 261 {
 262     SPPenContext *pc = SP_PEN_CONTEXT(ec);
 263
 264     if (pc->npoints != 0) {
 265         pen_cancel (pc);
 266     }
 267
 268     if (((SPEventContextClass *) pen_parent_class)->finish) {
 269         ((SPEventContextClass *) pen_parent_class)->finish(ec);
 270     }
 271 }
 272
 273 /**
 274  * Callback that sets key to value in pen context.
 275  */
 276 static void
 277 sp_pen_context_set(SPEventContext *ec, gchar const *key, gchar const *val)
 278 {
 279     SPPenContext *pc = SP_PEN_CONTEXT(ec);
 280
 281     if (!strcmp(key, "mode")) {
 282         if ( val && !strcmp(val, "drag") ) {
 283             pc->mode = SP_PEN_CONTEXT_MODE_DRAG;
 284         } else {
 285             pc->mode = SP_PEN_CONTEXT_MODE_CLICK;
 286         }
 287     }
 288 }
 289
 290 /**
 291  * Snaps new node relative to the previous node.
 292  */
 293 static void
 294 spdc_endpoint_snap(SPPenContext const *const pc, NR::Point &p, guint const state)
 295 {
 296     if ((state & GDK_CONTROL_MASK)) { //CTRL enables angular snapping
 297         if (pc->npoints > 0) {
 298             spdc_endpoint_snap_rotation(pc, p, pc->p[0], state);
 299         }
 300     } else {
 301         if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above
 302                                          //After all, the user explicitely asked for angular snapping by
 303                                          //pressing CTRL
 304             spdc_endpoint_snap_free(pc, p, state);
 305         }
 306     }
 307     if (pc->polylines_paraxial) {
 308         // TODO: must we avoid one of the snaps in the previous case distinction in some situations?
 309         pen_set_to_nearest_horiz_vert(pc, p, state);
 310     }
 311 }
 312
 313 /**
 314  * Snaps new node's handle relative to the new node.
 315  */
 316 static void
 317 spdc_endpoint_snap_handle(SPPenContext const *const pc, NR::Point &p, guint const state)
 318 {
 319     g_return_if_fail(( pc->npoints == 2 ||
 320                        pc->npoints == 5   ));
 321
 322     if ((state & GDK_CONTROL_MASK)) { //CTRL enables angular snapping
 323         spdc_endpoint_snap_rotation(pc, p, pc->p[pc->npoints - 2], state);
 324     } else {
 325         if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above
 326             spdc_endpoint_snap_free(pc, p, state);
 327         }
 328     }
 329 }
 330
 331 static gint
 332 sp_pen_context_item_handler(SPEventContext *ec, SPItem *item, GdkEvent *event)
 333 {
 334     SPPenContext *const pc = SP_PEN_CONTEXT(ec);
 335
 336     gint ret = FALSE;
 337
 338     switch (event->type) {
 339         case GDK_BUTTON_PRESS:
 340             ret = pen_handle_button_press(pc, event->button);
 341             break;
 342         case GDK_BUTTON_RELEASE:
 343             ret = pen_handle_button_release(pc, event->button);
 344             break;
 345         default:
 346             break;
 347     }
 348
 349     if (!ret) {
 350         if (((SPEventContextClass *) pen_parent_class)->item_handler)
 351             ret = ((SPEventContextClass *) pen_parent_class)->item_handler(ec, item, event);
 352     }
 353
 354     return ret;
 355 }
 356
 357 /**
 358  * Callback to handle all pen events.
 359  */
 360 static gint
 361 sp_pen_context_root_handler(SPEventContext *ec, GdkEvent *event)
 362 {
 363     SPPenContext *const pc = SP_PEN_CONTEXT(ec);
 364
 365     gint ret = FALSE;
 366
 367     switch (event->type) {
 368         case GDK_BUTTON_PRESS:
 369             ret = pen_handle_button_press(pc, event->button);
 370             break;
 371
 372         case GDK_MOTION_NOTIFY:
 373             ret = pen_handle_motion_notify(pc, event->motion);
 374             break;
 375
 376         case GDK_BUTTON_RELEASE:
 377             ret = pen_handle_button_release(pc, event->button);
 378             break;
 379
 380         case GDK_2BUTTON_PRESS:
 381             ret = pen_handle_2button_press(pc, event->button);
 382             break;
 383
 384         case GDK_KEY_PRESS:
 385             ret = pen_handle_key_press(pc, event);
 386             break;
 387
 388         default:
 389             break;
 390     }
 391
 392     if (!ret) {
 393         gint (*const parent_root_handler)(SPEventContext *, GdkEvent *)
 394             = ((SPEventContextClass *) pen_parent_class)->root_handler;
 395         if (parent_root_handler) {
 396             ret = parent_root_handler(ec, event);
 397         }
 398     }
 399
 400     return ret;
 401 }
 402
 403 /**
 404  * Handle mouse button press event.
 405  */
 406 static gint pen_handle_button_press(SPPenContext *const pc, GdkEventButton const &bevent)
 407 {
 408     if (pc->events_disabled) {
 409         // skip event processing if events are disabled
 410         return FALSE;
 411     }
 412
 413     SPDrawContext * const dc = SP_DRAW_CONTEXT(pc);
 414     SPDesktop * const desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 415     NR::Point const event_w(bevent.x, bevent.y);
 416     NR::Point const event_dt(desktop->w2d(event_w));
 417     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 418
 419     gint ret = FALSE;
 420     if (bevent.button == 1 && !event_context->space_panning
 421         // make sure this is not the last click for a waiting LPE (otherwise we want to finish the path)
 422         && pc->expecting_clicks_for_LPE != 1) {
 423
 424         if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 425             return TRUE;
 426         }
 427
 428         if (!pc->grab ) {
 429             /* Grab mouse, so release will not pass unnoticed */
 430             pc->grab = SP_CANVAS_ITEM(desktop->acetate);
 431             sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK   |
 432                                             GDK_BUTTON_RELEASE_MASK |
 433                                             GDK_POINTER_MOTION_MASK  ),
 434                                 NULL, bevent.time);
 435         }
 436
 437         pen_drag_origin_w = event_w;
 438         pen_within_tolerance = true;
 439
 440         /* Test whether we hit any anchor. */
 441         SPDrawAnchor * const anchor = spdc_test_inside(pc, event_w);
 442
 443         switch (pc->mode) {
 444             case SP_PEN_CONTEXT_MODE_CLICK:
 445                 /* In click mode we add point on release */
 446                 switch (pc->state) {
 447                     case SP_PEN_CONTEXT_POINT:
 448                     case SP_PEN_CONTEXT_CONTROL:
 449                     case SP_PEN_CONTEXT_CLOSE:
 450                         break;
 451                     case SP_PEN_CONTEXT_STOP:
 452                         /* This is allowed, if we just cancelled curve */
 453                         pc->state = SP_PEN_CONTEXT_POINT;
 454                         break;
 455                     default:
 456                         break;
 457                 }
 458                 break;
 459             case SP_PEN_CONTEXT_MODE_DRAG:
 460                 switch (pc->state) {
 461                     case SP_PEN_CONTEXT_STOP:
 462                         /* This is allowed, if we just cancelled curve */
 463                     case SP_PEN_CONTEXT_POINT:
 464                         if (pc->npoints == 0) {
 465
 466                             if (bevent.state & GDK_CONTROL_MASK) {
 467                                 freehand_create_single_dot(event_context, event_dt, "tools.freehand.pen", bevent.state);
 468                                 ret = TRUE;
 469                                 break;
 470                             }
 471
 472                             // TODO: Perhaps it would be nicer to rearrange the following case
 473                             // distinction so that the case of a waiting LPE is treated separately
 474
 475                             /* Set start anchor */
 476                             pc->sa = anchor;
 477                             NR::Point p;
 478                             if (anchor && !sp_pen_context_has_waiting_LPE(pc)) {
 479                                 /* Adjust point to anchor if needed; if we have a waiting LPE, we need
 480                                    a fresh path to be created so don't continue an existing one */
 481                                 p = anchor->dp;
 482                                 desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Continuing selected path"));
 483                             } else {
 484                                 // This is the first click of a new curve; deselect item so that
 485                                 // this curve is not combined with it (unless it is drawn from its
 486                                 // anchor, which is handled by the sibling branch above)
 487                                 Inkscape::Selection * const selection = sp_desktop_selection(desktop);
 488                                 if (!(bevent.state & GDK_SHIFT_MASK) || sp_pen_context_has_waiting_LPE(pc)) {
 489                                     /* if we have a waiting LPE, we need a fresh path to be created
 490                                        so don't append to an existing one */
 491                                     selection->clear();
 492                                     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Creating new path"));
 493                                 } else if (selection->singleItem() && SP_IS_PATH(selection->singleItem())) {
 494                                     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Appending to selected path"));
 495                                 }
 496
 497                                 /* Create green anchor */
 498                                 p = event_dt;
 499                                 if (!pc->polylines_paraxial) {
 500                                     // only snap the starting point if we're not in horizontal/vertical mode
 501                                     // because otherwise it gets shifted; TODO: why do we snap here at all??
 502                                     spdc_endpoint_snap(pc, p, bevent.state);
 503                                 }
 504                                 pc->green_anchor = sp_draw_anchor_new(pc, pc->green_curve, TRUE, p);
 505                             }
 506                             spdc_pen_set_initial_point(pc, p);
 507                         } else {
 508
 509                             /* Set end anchor */
 510                             pc->ea = anchor;
 511                             NR::Point p;
 512                             if (anchor) {
 513                                 p = anchor->dp;
 514                                 // we hit an anchor, will finish the curve (either with or without closing)
 515                                 // in release handler
 516                                 pc->state = SP_PEN_CONTEXT_CLOSE;
 517
 518                                 if (pc->green_anchor && pc->green_anchor->active) {
 519                                     // we clicked on the current curve start, so close it even if
 520                                     // we drag a handle away from it
 521                                     dc->green_closed = TRUE;
 522                                 }
 523                                 ret = TRUE;
 524                                 break;
 525
 526                             } else {
 527                                 p = event_dt;
 528                                 spdc_endpoint_snap(pc, p, bevent.state); /* Snap node only if not hitting anchor. */
 529                                 spdc_pen_set_subsequent_point(pc, p, true);
 530                                 if (pc->polylines_only) {
 531                                     spdc_pen_finish_segment(pc, p, bevent.state);
 532                                 }
 533                             }
 534                         }
 535
 536                         pc->state = pc->polylines_only ? SP_PEN_CONTEXT_POINT : SP_PEN_CONTEXT_CONTROL;
 537                         ret = TRUE;
 538                         break;
 539                     case SP_PEN_CONTEXT_CONTROL:
 540                         g_warning("Button down in CONTROL state");
 541                         break;
 542                     case SP_PEN_CONTEXT_CLOSE:
 543                         g_warning("Button down in CLOSE state");
 544                         break;
 545                     default:
 546                         break;
 547                 }
 548                 break;
 549             default:
 550                 break;
 551         }
 552     } 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
 553         if (pc->npoints != 0) {
 554
 555             spdc_pen_finish_segment(pc, event_dt, bevent.state);
 556             if (pc->green_closed) {
 557                 // finishing at the start anchor, close curve
 558                 spdc_pen_finish(pc, TRUE);
 559             } else {
 560                 // finishing at some other anchor, finish curve but not close
 561                 spdc_pen_finish(pc, FALSE);
 562             }
 563
 564             ret = TRUE;
 565         }
 566     }
 567
 568     if (pc->expecting_clicks_for_LPE > 0) {
 569         --pc->expecting_clicks_for_LPE;
 570     }
 571
 572     return ret;
 573 }
 574
 575 /**
 576  * Handle motion_notify event.
 577  */
 578 static gint
 579 pen_handle_motion_notify(SPPenContext *const pc, GdkEventMotion const &mevent)
 580 {
 581     gint ret = FALSE;
 582
 583     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 584     SPDesktop * const dt = SP_EVENT_CONTEXT_DESKTOP(event_context);
 585
 586     if (event_context->space_panning || mevent.state & GDK_BUTTON2_MASK || mevent.state & GDK_BUTTON3_MASK) {
 587         // allow scrolling
 588         return FALSE;
 589     }
 590
 591     if (pc->events_disabled) {
 592         // skip motion events if pen events are disabled
 593         return FALSE;
 594     }
 595
 596     NR::Point const event_w(mevent.x,
 597                             mevent.y);
 598     if (pen_within_tolerance) {
 599         gint const tolerance = prefs_get_int_attribute_limited("options.dragtolerance",
 600                                                                "value", 0, 0, 100);
 601         if ( NR::LInfty( event_w - pen_drag_origin_w ) < tolerance ) {
 602             return FALSE;   // Do not drag if we're within tolerance from origin.
 603         }
 604     }
 605     // Once the user has moved farther than tolerance from the original location
 606     // (indicating they intend to move the object, not click), then always process the
 607     // motion notify coordinates as given (no snapping back to origin)
 608     pen_within_tolerance = false;
 609
 610     /* Find desktop coordinates */
 611     NR::Point p = dt->w2d(event_w);
 612
 613     /* Test, whether we hit any anchor */
 614     SPDrawAnchor *anchor = spdc_test_inside(pc, event_w);
 615
 616     switch (pc->mode) {
 617         case SP_PEN_CONTEXT_MODE_CLICK:
 618             switch (pc->state) {
 619                 case SP_PEN_CONTEXT_POINT:
 620                     if ( pc->npoints != 0 ) {
 621                         /* Only set point, if we are already appending */
 622                         spdc_endpoint_snap(pc, p, mevent.state);
 623                         spdc_pen_set_subsequent_point(pc, p, true);
 624                         ret = TRUE;
 625                     }
 626                     break;
 627                 case SP_PEN_CONTEXT_CONTROL:
 628                 case SP_PEN_CONTEXT_CLOSE:
 629                     /* Placing controls is last operation in CLOSE state */
 630                     spdc_endpoint_snap(pc, p, mevent.state);
 631                     spdc_pen_set_ctrl(pc, p, mevent.state);
 632                     ret = TRUE;
 633                     break;
 634                 case SP_PEN_CONTEXT_STOP:
 635                     /* This is perfectly valid */
 636                     break;
 637                 default:
 638                     break;
 639             }
 640             break;
 641         case SP_PEN_CONTEXT_MODE_DRAG:
 642             switch (pc->state) {
 643                 case SP_PEN_CONTEXT_POINT:
 644                     if ( pc->npoints > 0 ) {
 645                         /* Only set point, if we are already appending */
 646
 647                         if (!anchor) {   /* Snap node only if not hitting anchor */
 648                             spdc_endpoint_snap(pc, p, mevent.state);
 649                         }
 650
 651                         spdc_pen_set_subsequent_point(pc, p, !anchor, mevent.state);
 652
 653                         if (anchor && !pc->anchor_statusbar) {
 654                             pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to close and finish the path."));
 655                             pc->anchor_statusbar = true;
 656                         } else if (!anchor && pc->anchor_statusbar) {
 657                             pc->_message_context->clear();
 658                             pc->anchor_statusbar = false;
 659                         }
 660
 661                         ret = TRUE;
 662                     } else {
 663                         if (anchor && !pc->anchor_statusbar) {
 664                             pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to continue the path from this point."));
 665                             pc->anchor_statusbar = true;
 666                         } else if (!anchor && pc->anchor_statusbar) {
 667                             pc->_message_context->clear();
 668                             pc->anchor_statusbar = false;
 669                         }
 670                     }
 671                     break;
 672                 case SP_PEN_CONTEXT_CONTROL:
 673                 case SP_PEN_CONTEXT_CLOSE:
 674                     /* Placing controls is last operation in CLOSE state */
 675
 676                     // snap the handle
 677                     spdc_endpoint_snap_handle(pc, p, mevent.state);
 678
 679                     if (!pc->polylines_only) {
 680                         spdc_pen_set_ctrl(pc, p, mevent.state);
 681                     } else {
 682                         spdc_pen_set_ctrl(pc, pc->p[1], mevent.state);
 683                     }
 684                     gobble_motion_events(GDK_BUTTON1_MASK);
 685                     ret = TRUE;
 686                     break;
 687                 case SP_PEN_CONTEXT_STOP:
 688                     /* This is perfectly valid */
 689                     break;
 690                 default:
 691                     break;
 692             }
 693             break;
 694         default:
 695             break;
 696     }
 697     return ret;
 698 }
 699
 700 /**
 701  * Handle mouse button release event.
 702  */
 703 static gint
 704 pen_handle_button_release(SPPenContext *const pc, GdkEventButton const &revent)
 705 {
 706     if (pc->events_disabled) {
 707         // skip event processing if events are disabled
 708         return FALSE;
 709     }
 710
 711     gint ret = FALSE;
 712     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 713     if ( revent.button == 1  && !event_context->space_panning) {
 714
 715         SPDrawContext *dc = SP_DRAW_CONTEXT (pc);
 716
 717         NR::Point const event_w(revent.x,
 718                                 revent.y);
 719         /* Find desktop coordinates */
 720         NR::Point p = pc->desktop->w2d(event_w);
 721
 722         /* Test whether we hit any anchor. */
 723         SPDrawAnchor *anchor = spdc_test_inside(pc, event_w);
 724
 725         switch (pc->mode) {
 726             case SP_PEN_CONTEXT_MODE_CLICK:
 727                 switch (pc->state) {
 728                     case SP_PEN_CONTEXT_POINT:
 729                         if ( pc->npoints == 0 ) {
 730                             /* Start new thread only with button release */
 731                             if (anchor) {
 732                                 p = anchor->dp;
 733                             }
 734                             pc->sa = anchor;
 735                             spdc_pen_set_initial_point(pc, p);
 736                         } else {
 737                             /* Set end anchor here */
 738                             pc->ea = anchor;
 739                             if (anchor) {
 740                                 p = anchor->dp;
 741                             }
 742                         }
 743                         pc->state = SP_PEN_CONTEXT_CONTROL;
 744                         ret = TRUE;
 745                         break;
 746                     case SP_PEN_CONTEXT_CONTROL:
 747                         /* End current segment */
 748                         spdc_endpoint_snap(pc, p, revent.state);
 749                         spdc_pen_finish_segment(pc, p, revent.state);
 750                         pc->state = SP_PEN_CONTEXT_POINT;
 751                         ret = TRUE;
 752                         break;
 753                     case SP_PEN_CONTEXT_CLOSE:
 754                         /* End current segment */
 755                         if (!anchor) {   /* Snap node only if not hitting anchor */
 756                             spdc_endpoint_snap(pc, p, revent.state);
 757                         }
 758                         spdc_pen_finish_segment(pc, p, revent.state);
 759                         spdc_pen_finish(pc, TRUE);
 760                         pc->state = SP_PEN_CONTEXT_POINT;
 761                         ret = TRUE;
 762                         break;
 763                     case SP_PEN_CONTEXT_STOP:
 764                         /* This is allowed, if we just cancelled curve */
 765                         pc->state = SP_PEN_CONTEXT_POINT;
 766                         ret = TRUE;
 767                         break;
 768                     default:
 769                         break;
 770                 }
 771                 break;
 772             case SP_PEN_CONTEXT_MODE_DRAG:
 773                 switch (pc->state) {
 774                     case SP_PEN_CONTEXT_POINT:
 775                     case SP_PEN_CONTEXT_CONTROL:
 776                         if (!pc->polylines_only) {
 777                             spdc_endpoint_snap(pc, p, revent.state);
 778                             spdc_pen_finish_segment(pc, p, revent.state);
 779                         }
 780                         break;
 781                     case SP_PEN_CONTEXT_CLOSE:
 782                         spdc_endpoint_snap(pc, p, revent.state);
 783                         spdc_pen_finish_segment(pc, p, revent.state);
 784                         if (pc->green_closed) {
 785                             // finishing at the start anchor, close curve
 786                             spdc_pen_finish(pc, TRUE);
 787                         } else {
 788                             // finishing at some other anchor, finish curve but not close
 789                             spdc_pen_finish(pc, FALSE);
 790                         }
 791                         break;
 792                     case SP_PEN_CONTEXT_STOP:
 793                         /* This is allowed, if we just cancelled curve */
 794                         break;
 795                     default:
 796                         break;
 797                 }
 798                 pc->state = SP_PEN_CONTEXT_POINT;
 799                 ret = TRUE;
 800                 break;
 801             default:
 802                 break;
 803         }
 804
 805         if (pc->grab) {
 806             /* Release grab now */
 807             sp_canvas_item_ungrab(pc->grab, revent.time);
 808             pc->grab = NULL;
 809         }
 810
 811         ret = TRUE;
 812
 813         dc->green_closed = FALSE;
 814     }
 815
 816     // TODO: can we be sure that the path was created correctly?
 817     // TODO: should we offer an option to collect the clicks in a list?
 818     if (pc->expecting_clicks_for_LPE == 0 && sp_pen_context_has_waiting_LPE(pc)) {
 819         sp_pen_context_set_polyline_mode(pc);
 820
 821         SPEventContext *ec = SP_EVENT_CONTEXT(pc);
 822         Inkscape::Selection *selection = sp_desktop_selection (ec->desktop);
 823
 824         if (pc->waiting_LPE) {
 825             // we have an already created LPE waiting for a path
 826             pc->waiting_LPE->acceptParamPath(SP_PATH(selection->singleItem()));
 827             selection->add(SP_OBJECT(pc->waiting_item));
 828             pc->waiting_LPE = NULL;
 829         } else {
 830             // the case that we need to create a new LPE and apply it to the just-drawn path is
 831             // handled in spdc_check_for_and_apply_waiting_LPE() in draw-context.cpp
 832         }
 833     }
 834
 835     return ret;
 836 }
 837
 838 static gint
 839 pen_handle_2button_press(SPPenContext *const pc, GdkEventButton const &bevent)
 840 {
 841     gint ret = FALSE;
 842     if (pc->npoints != 0 && bevent.button != 2) {
 843         spdc_pen_finish(pc, FALSE);
 844         ret = TRUE;
 845     }
 846     return ret;
 847 }
 848
 849 void
 850 pen_redraw_all (SPPenContext *const pc)
 851 {
 852     // green
 853     if (pc->green_bpaths) {
 854         // remove old piecewise green canvasitems
 855         while (pc->green_bpaths) {
 856             gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
 857             pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
 858         }
 859         // one canvas bpath for all of green_curve
 860         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), pc->green_curve);
 861         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 862         sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cshape), 0, SP_WIND_RULE_NONZERO);
 863
 864         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
 865     }
 866
 867     if (pc->green_anchor)
 868         SP_CTRL(pc->green_anchor->ctrl)->moveto(pc->green_anchor->dp);
 869
 870     pc->red_curve->reset();
 871     pc->red_curve->moveto(pc->p[0]);
 872     pc->red_curve->curveto(pc->p[1], pc->p[2], pc->p[3]);
 873     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 874
 875     // handles
 876     if (pc->p[0] != pc->p[1]) {
 877         SP_CTRL(pc->c1)->moveto(pc->p[1]);
 878         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[0], pc->p[1]);
 879         sp_canvas_item_show (pc->c1);
 880         sp_canvas_item_show (pc->cl1);
 881     } else {
 882         sp_canvas_item_hide (pc->c1);
 883         sp_canvas_item_hide (pc->cl1);
 884     }
 885
 886     Geom::Curve const * last_seg = pc->green_curve->last_segment();
 887     if (last_seg) {
 888         Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>( last_seg );
 889         if ( cubic &&
 890              (*cubic)[2] != to_2geom(pc->p[0]) )
 891         {
 892             NR::Point p2 = (*cubic)[2];
 893             SP_CTRL(pc->c0)->moveto(p2);
 894             sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl0), p2, pc->p[0]);
 895             sp_canvas_item_show (pc->c0);
 896             sp_canvas_item_show (pc->cl0);
 897         } else {
 898             sp_canvas_item_hide (pc->c0);
 899             sp_canvas_item_hide (pc->cl0);
 900         }
 901     }
 902 }
 903
 904 void
 905 pen_lastpoint_move (SPPenContext *const pc, gdouble x, gdouble y)
 906 {
 907     if (pc->npoints != 5)
 908         return;
 909
 910     // green
 911     if (!pc->green_curve->is_empty()) {
 912         pc->green_curve->last_point_additive_move( Geom::Point(x,y) );
 913     } else {
 914         // start anchor too
 915         if (pc->green_anchor) {
 916             pc->green_anchor->dp += NR::Point(x, y);
 917         }
 918     }
 919
 920     // red
 921     pc->p[0] += NR::Point(x, y);
 922     pc->p[1] += NR::Point(x, y);
 923     pen_redraw_all(pc);
 924 }
 925
 926 void
 927 pen_lastpoint_move_screen (SPPenContext *const pc, gdouble x, gdouble y)
 928 {
 929     pen_lastpoint_move (pc, x / pc->desktop->current_zoom(), y / pc->desktop->current_zoom());
 930 }
 931
 932 void
 933 pen_lastpoint_tocurve (SPPenContext *const pc)
 934 {
 935     if (pc->npoints != 5)
 936         return;
 937
 938     Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>( pc->green_curve->last_segment() );
 939     if ( cubic ) {
 940         pc->p[1] = pc->p[0] + (NR::Point)( (*cubic)[3] - (*cubic)[2] );
 941     } else {
 942         pc->p[1] = pc->p[0] + (1./3)*(pc->p[3] - pc->p[0]);
 943     }
 944
 945     pen_redraw_all(pc);
 946 }
 947
 948 void
 949 pen_lastpoint_toline (SPPenContext *const pc)
 950 {
 951     if (pc->npoints != 5)
 952         return;
 953
 954     pc->p[1] = pc->p[0];
 955
 956     pen_redraw_all(pc);
 957 }
 958
 959
 960 static gint
 961 pen_handle_key_press(SPPenContext *const pc, GdkEvent *event)
 962 {
 963     gint ret = FALSE;
 964     gdouble const nudge = prefs_get_double_attribute_limited("options.nudgedistance", "value", 2, 0, 1000); // in px
 965
 966     switch (get_group0_keyval (&event->key)) {
 967
 968         case GDK_Left: // move last point left
 969         case GDK_KP_Left:
 970         case GDK_KP_4:
 971             if (!MOD__CTRL) { // not ctrl
 972                 if (MOD__ALT) { // alt
 973                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, -10, 0); // shift
 974                     else pen_lastpoint_move_screen(pc, -1, 0); // no shift
 975                 }
 976                 else { // no alt
 977                     if (MOD__SHIFT) pen_lastpoint_move(pc, -10*nudge, 0); // shift
 978                     else pen_lastpoint_move(pc, -nudge, 0); // no shift
 979                 }
 980                 ret = TRUE;
 981             }
 982             break;
 983         case GDK_Up: // move last point up
 984         case GDK_KP_Up:
 985         case GDK_KP_8:
 986             if (!MOD__CTRL) { // not ctrl
 987                 if (MOD__ALT) { // alt
 988                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 0, 10); // shift
 989                     else pen_lastpoint_move_screen(pc, 0, 1); // no shift
 990                 }
 991                 else { // no alt
 992                     if (MOD__SHIFT) pen_lastpoint_move(pc, 0, 10*nudge); // shift
 993                     else pen_lastpoint_move(pc, 0, nudge); // no shift
 994                 }
 995                 ret = TRUE;
 996             }
 997             break;
 998         case GDK_Right: // move last point right
 999         case GDK_KP_Right:
1000         case GDK_KP_6:
1001             if (!MOD__CTRL) { // not ctrl
1002                 if (MOD__ALT) { // alt
1003                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 10, 0); // shift
1004                     else pen_lastpoint_move_screen(pc, 1, 0); // no shift
1005                 }
1006                 else { // no alt
1007                     if (MOD__SHIFT) pen_lastpoint_move(pc, 10*nudge, 0); // shift
1008                     else pen_lastpoint_move(pc, nudge, 0); // no shift
1009                 }
1010                 ret = TRUE;
1011             }
1012             break;
1013         case GDK_Down: // move last point down
1014         case GDK_KP_Down:
1015         case GDK_KP_2:
1016             if (!MOD__CTRL) { // not ctrl
1017                 if (MOD__ALT) { // alt
1018                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 0, -10); // shift
1019                     else pen_lastpoint_move_screen(pc, 0, -1); // no shift
1020                 }
1021                 else { // no alt
1022                     if (MOD__SHIFT) pen_lastpoint_move(pc, 0, -10*nudge); // shift
1023                     else pen_lastpoint_move(pc, 0, -nudge); // no shift
1024                 }
1025                 ret = TRUE;
1026             }
1027             break;
1028
1029         case GDK_P:
1030         case GDK_p:
1031             if (MOD__SHIFT_ONLY) {
1032                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::PARALLEL, 2);
1033                 ret = TRUE;
1034             }
1035             break;
1036
1037         case GDK_C:
1038         case GDK_c:
1039             if (MOD__SHIFT_ONLY) {
1040                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::CIRCLE_3PTS, 3);
1041                 ret = TRUE;
1042             }
1043             break;
1044
1045         case GDK_B:
1046         case GDK_b:
1047             if (MOD__SHIFT_ONLY) {
1048                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::PERP_BISECTOR, 2);
1049                 ret = TRUE;
1050             }
1051             break;
1052
1053         case GDK_A:
1054         case GDK_a:
1055             if (MOD__SHIFT_ONLY) {
1056                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::ANGLE_BISECTOR, 3);
1057                 ret = TRUE;
1058             }
1059             break;
1060
1061         case GDK_U:
1062         case GDK_u:
1063             if (MOD__SHIFT_ONLY) {
1064                 pen_lastpoint_tocurve(pc);
1065                 ret = TRUE;
1066             }
1067             break;
1068         case GDK_L:
1069         case GDK_l:
1070             if (MOD__SHIFT_ONLY) {
1071                 pen_lastpoint_toline(pc);
1072                 ret = TRUE;
1073             }
1074             break;
1075
1076         case GDK_Return:
1077         case GDK_KP_Enter:
1078             if (pc->npoints != 0) {
1079                 spdc_pen_finish(pc, FALSE);
1080                 ret = TRUE;
1081             }
1082             break;
1083         case GDK_Escape:
1084             if (pc->npoints != 0) {
1085                 // if drawing, cancel, otherwise pass it up for deselecting
1086                 pen_cancel (pc);
1087                 ret = TRUE;
1088             }
1089             break;
1090         case GDK_z:
1091         case GDK_Z:
1092             if (MOD__CTRL_ONLY && pc->npoints != 0) {
1093                 // if drawing, cancel, otherwise pass it up for undo
1094                 pen_cancel (pc);
1095                 ret = TRUE;
1096             }
1097             break;
1098         case GDK_g:
1099         case GDK_G:
1100             if (MOD__SHIFT_ONLY) {
1101                 sp_selection_to_guides(SP_EVENT_CONTEXT(pc)->desktop);
1102                 ret = true;
1103             }
1104             break;
1105         case GDK_BackSpace:
1106         case GDK_Delete:
1107         case GDK_KP_Delete:
1108             if (pc->green_curve->is_empty()) {
1109                 if (!pc->red_curve->is_empty()) {
1110                     pen_cancel (pc);
1111                     ret = TRUE;
1112                 } else {
1113                     // do nothing; this event should be handled upstream
1114                 }
1115             } else {
1116                 /* Reset red curve */
1117                 pc->red_curve->reset();
1118                 /* Destroy topmost green bpath */
1119                 if (pc->green_bpaths) {
1120                     if (pc->green_bpaths->data)
1121                         gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
1122                     pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
1123                 }
1124                 /* Get last segment */
1125                 if ( pc->green_curve->is_empty() ) {
1126                     g_warning("pen_handle_key_press, case GDK_KP_Delete: Green curve is empty");
1127                     break;
1128                 }
1129                 // The code below assumes that pc->green_curve has only ONE path !
1130                 Geom::Path const & path = pc->green_curve->get_pathvector().back();
1131                 Geom::Curve const * crv = &path.back_default();
1132                 pc->p[0] = crv->initialPoint();
1133                 if ( Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>(crv)) {
1134                     pc->p[1] = (*cubic)[1];
1135                 } else {
1136                     pc->p[1] = pc->p[0];
1137                 }
1138                 NR::Point const pt(( pc->npoints < 4
1139                                      ? (NR::Point)(crv->finalPoint())
1140                                      : pc->p[3] ));
1141                 pc->npoints = 2;
1142                 pc->green_curve->backspace();
1143                 sp_canvas_item_hide(pc->c0);
1144                 sp_canvas_item_hide(pc->c1);
1145                 sp_canvas_item_hide(pc->cl0);
1146                 sp_canvas_item_hide(pc->cl1);
1147                 pc->state = SP_PEN_CONTEXT_POINT;
1148                 spdc_pen_set_subsequent_point(pc, pt, true);
1149                 ret = TRUE;
1150             }
1151             break;
1152         default:
1153             break;
1154     }
1155     return ret;
1156 }
1157
1158 static void
1159 spdc_reset_colors(SPPenContext *pc)
1160 {
1161     /* Red */
1162     pc->red_curve->reset();
1163     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
1164     /* Blue */
1165     pc->blue_curve->reset();
1166     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->blue_bpath), NULL);
1167     /* Green */
1168     while (pc->green_bpaths) {
1169         gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
1170         pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
1171     }
1172     pc->green_curve->reset();
1173     if (pc->green_anchor) {
1174         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
1175     }
1176     pc->sa = NULL;
1177     pc->ea = NULL;
1178     pc->npoints = 0;
1179     pc->red_curve_is_valid = false;
1180 }
1181
1182
1183 static void
1184 spdc_pen_set_initial_point(SPPenContext *const pc, NR::Point const p)
1185 {
1186     g_assert( pc->npoints == 0 );
1187
1188     pc->p[0] = p;
1189     pc->p[1] = p;
1190     pc->npoints = 2;
1191     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
1192
1193     sp_canvas_force_full_redraw_after_interruptions(pc->desktop->canvas, 5);
1194 }
1195
1196 /**
1197  * Show the status message for the current line/curve segment.
1198  * This type of message always shows angle/distance as the last
1199  * two parameters ("angle %3.2f&#176;, distance %s").
1200  */
1201 static void
1202 spdc_pen_set_angle_distance_status_message(SPPenContext *const pc, NR::Point const p, int pc_point_to_compare, gchar const *message)
1203 {
1204     g_assert(pc != NULL);
1205     g_assert((pc_point_to_compare == 0) || (pc_point_to_compare == 3)); // exclude control handles
1206     g_assert(message != NULL);
1207
1208     SPDesktop *desktop = SP_EVENT_CONTEXT(pc)->desktop;
1209     NR::Point rel = p - pc->p[pc_point_to_compare];
1210     GString *dist = SP_PX_TO_METRIC_STRING(NR::L2(rel), desktop->namedview->getDefaultMetric());
1211     double angle = atan2(rel[NR::Y], rel[NR::X]) * 180 / M_PI;
1212     if (prefs_get_int_attribute("options.compassangledisplay", "value", 0) != 0)
1213         angle = angle_to_compass (angle);
1214
1215     pc->_message_context->setF(Inkscape::IMMEDIATE_MESSAGE, message, angle, dist->str);
1216     g_string_free(dist, FALSE);
1217 }
1218
1219 static void
1220 spdc_pen_set_subsequent_point(SPPenContext *const pc, NR::Point const p, bool statusbar, guint status)
1221 {
1222     g_assert( pc->npoints != 0 );
1223     /* todo: Check callers to see whether 2 <= npoints is guaranteed. */
1224
1225     pc->p[2] = p;
1226     pc->p[3] = p;
1227     pc->p[4] = p;
1228     pc->npoints = 5;
1229     pc->red_curve->reset();
1230     bool is_curve;
1231     pc->red_curve->moveto(pc->p[0]);
1232     if (pc->polylines_paraxial && !statusbar) {
1233         // we are drawing horizontal/vertical lines and hit an anchor; draw an L-shaped path
1234         NR::Point intermed = p;
1235         pen_set_to_nearest_horiz_vert(pc, intermed, status);
1236         pc->red_curve->lineto(intermed);
1237         pc->red_curve->lineto(p);
1238         is_curve = false;
1239     } else {
1240         // one of the 'regular' modes
1241         if (pc->p[1] != pc->p[0])
1242         {
1243             pc->red_curve->curveto(pc->p[1], p, p);
1244             is_curve = true;
1245         } else {
1246             pc->red_curve->lineto(p);
1247             is_curve = false;
1248         }
1249     }
1250
1251     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
1252
1253     if (statusbar) {
1254         gchar *message = is_curve ?
1255             _("<b>Curve segment</b>: angle %3.2f&#176;, distance %s; with <b>Ctrl</b> to snap angle, <b>Enter</b> to finish the path" ):
1256             _("<b>Line segment</b>: angle %3.2f&#176;, distance %s; with <b>Ctrl</b> to snap angle, <b>Enter</b> to finish the path");
1257         spdc_pen_set_angle_distance_status_message(pc, p, 0, message);
1258     }
1259 }
1260
1261 static void
1262 spdc_pen_set_ctrl(SPPenContext *const pc, NR::Point const p, guint const state)
1263 {
1264     sp_canvas_item_show(pc->c1);
1265     sp_canvas_item_show(pc->cl1);
1266
1267     if ( pc->npoints == 2 ) {
1268         pc->p[1] = p;
1269         sp_canvas_item_hide(pc->c0);
1270         sp_canvas_item_hide(pc->cl0);
1271         SP_CTRL(pc->c1)->moveto(pc->p[1]);
1272         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[0], pc->p[1]);
1273
1274         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"));
1275     } else if ( pc->npoints == 5 ) {
1276         pc->p[4] = p;
1277         sp_canvas_item_show(pc->c0);
1278         sp_canvas_item_show(pc->cl0);
1279         bool is_symm = false;
1280         if ( ( ( pc->mode == SP_PEN_CONTEXT_MODE_CLICK ) && ( state & GDK_CONTROL_MASK ) ) ||
1281              ( ( pc->mode == SP_PEN_CONTEXT_MODE_DRAG ) &&  !( state & GDK_SHIFT_MASK  ) ) ) {
1282             NR::Point delta = p - pc->p[3];
1283             pc->p[2] = pc->p[3] - delta;
1284             is_symm = true;
1285             pc->red_curve->reset();
1286             pc->red_curve->moveto(pc->p[0]);
1287             pc->red_curve->curveto(pc->p[1], pc->p[2], pc->p[3]);
1288             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
1289         }
1290         SP_CTRL(pc->c0)->moveto(pc->p[2]);
1291         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl0), pc->p[3], pc->p[2]);
1292         SP_CTRL(pc->c1)->moveto(pc->p[4]);
1293         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[3], pc->p[4]);
1294
1295         gchar *message = is_symm ?
1296             _("<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") :
1297             _("<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");
1298         spdc_pen_set_angle_distance_status_message(pc, p, 3, message);
1299     } else {
1300         g_warning("Something bad happened - npoints is %d", pc->npoints);
1301     }
1302 }
1303
1304 static void
1305 spdc_pen_finish_segment(SPPenContext *const pc, NR::Point const p, guint const state)
1306 {
1307     if (pc->polylines_paraxial) {
1308         pen_last_paraxial_dir = pen_next_paraxial_direction(pc, p, pc->p[0], state);
1309     }
1310     ++pc->num_clicks;
1311
1312     if (!pc->red_curve->is_empty()) {
1313         pc->green_curve->append_continuous(pc->red_curve, 0.0625);
1314         SPCurve *curve = pc->red_curve->copy();
1315         /// \todo fixme:
1316         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), curve);
1317         curve->unref();
1318         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
1319
1320         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
1321
1322         pc->p[0] = pc->p[3];
1323         pc->p[1] = pc->p[4];
1324         pc->npoints = 2;
1325
1326         pc->red_curve->reset();
1327     }
1328 }
1329
1330 static void
1331 spdc_pen_finish(SPPenContext *const pc, gboolean const closed)
1332 {
1333     if (pc->expecting_clicks_for_LPE > 1) {
1334         // don't let the path be finished before we have collected the required number of mouse clicks
1335         return;
1336     }
1337
1338     pc->num_clicks = 0;
1339
1340     pen_disable_events(pc);
1341
1342     SPDesktop *const desktop = pc->desktop;
1343     pc->_message_context->clear();
1344     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Drawing finished"));
1345
1346     pc->red_curve->reset();
1347     spdc_concat_colors_and_flush(pc, closed);
1348     pc->sa = NULL;
1349     pc->ea = NULL;
1350
1351     pc->npoints = 0;
1352     pc->state = SP_PEN_CONTEXT_POINT;
1353
1354     sp_canvas_item_hide(pc->c0);
1355     sp_canvas_item_hide(pc->c1);
1356     sp_canvas_item_hide(pc->cl0);
1357     sp_canvas_item_hide(pc->cl1);
1358
1359     if (pc->green_anchor) {
1360         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
1361     }
1362
1363
1364     sp_canvas_end_forced_full_redraws(pc->desktop->canvas);
1365
1366     pen_enable_events(pc);
1367 }
1368
1369 static void
1370 pen_disable_events(SPPenContext *const pc) {
1371   pc->events_disabled++;
1372 }
1373
1374 static void
1375 pen_enable_events(SPPenContext *const pc) {
1376   g_return_if_fail(pc->events_disabled != 0);
1377
1378   pc->events_disabled--;
1379 }
1380
1381 void
1382 sp_pen_context_wait_for_LPE_mouse_clicks(SPPenContext *pc, Inkscape::LivePathEffect::EffectType effect_type,
1383                                          unsigned int num_clicks, bool use_polylines)
1384 {
1385     g_print ("Now waiting for %s to be applied\n",
1386              Inkscape::LivePathEffect::LPETypeConverter.get_label(effect_type).c_str());
1387     g_return_if_fail(effect_type != Inkscape::LivePathEffect::INVALID_LPE);
1388
1389     pc->waiting_LPE_type = effect_type;
1390     pc->expecting_clicks_for_LPE = num_clicks;
1391     pc->polylines_only = use_polylines;
1392     pc->polylines_paraxial = false; // TODO: think if this is correct for all cases
1393 }
1394
1395 static int pen_next_paraxial_direction(const SPPenContext *const pc,
1396                                        NR::Point const &pt, NR::Point const &origin, guint state) {
1397     /*
1398      * after the first mouse click we determine whether the mouse pointer is closest to a
1399      * horizontal or vertical segment; for all subsequent mouse clicks, we use the direction
1400      * orthogonal to the last one; pressing Shift toggles the direction
1401      */
1402     if (pc->num_clicks == 0) {
1403         // first mouse click
1404         double dist_h = fabs(pt[NR::X] - origin[NR::X]);
1405         double dist_v = fabs(pt[NR::Y] - origin[NR::Y]);
1406         int ret = (dist_h < dist_v) ? 1 : 0; // 0 = horizontal, 1 = vertical
1407         pen_last_paraxial_dir = (state & GDK_SHIFT_MASK) ? 1 - ret : ret;
1408         return pen_last_paraxial_dir;
1409     } else {
1410         // subsequent mouse click
1411         return (state & GDK_SHIFT_MASK) ? pen_last_paraxial_dir : 1 - pen_last_paraxial_dir;
1412     }
1413 }
1414
1415 void pen_set_to_nearest_horiz_vert(const SPPenContext *const pc, NR::Point &pt, guint const state)
1416 {
1417     NR::Point const &origin = pc->p[0];
1418
1419     int next_dir = pen_next_paraxial_direction(pc, pt, origin, state);
1420
1421     if (next_dir == 0) {
1422         // line is forced to be horizontal
1423         pt[NR::Y] = origin[NR::Y];
1424     } else {
1425         // line is forced to be vertical
1426         pt[NR::X] = origin[NR::X];
1427     }
1428 }
1429
1430 NR::Point pen_get_intermediate_horiz_vert(const SPPenContext *const pc, NR::Point const &pt)
1431 {
1432     NR::Point const &origin = pc->p[0];
1433
1434     if (pen_last_paraxial_dir == 0) {
1435         return NR::Point (origin[NR::X], pt[NR::Y]);
1436     } else {
1437         return NR::Point (pt[NR::X], origin[NR::Y]);
1438     }
1439 }
1440
1441 /*
1442   Local Variables:
1443   mode:c++
1444   c-file-style:"stroustrup"
1445   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1446   indent-tabs-mode:nil
1447   fill-column:99
1448   End:
1449 */
1450 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :