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     SPPenContext *const pc = SP_PEN_CONTEXT(ec);
 365
 366     gint ret = FALSE;
 367
 368     switch (event->type) {
 369         case GDK_BUTTON_PRESS:
 370             ret = pen_handle_button_press(pc, event->button);
 371             break;
 372
 373         case GDK_MOTION_NOTIFY:
 374             ret = pen_handle_motion_notify(pc, event->motion);
 375             break;
 376
 377         case GDK_BUTTON_RELEASE:
 378             ret = pen_handle_button_release(pc, event->button);
 379             break;
 380
 381         case GDK_2BUTTON_PRESS:
 382             ret = pen_handle_2button_press(pc, event->button);
 383             break;
 384
 385         case GDK_KEY_PRESS:
 386             ret = pen_handle_key_press(pc, event);
 387             break;
 388
 389         default:
 390             break;
 391     }
 392
 393     if (!ret) {
 394         gint (*const parent_root_handler)(SPEventContext *, GdkEvent *)
 395             = ((SPEventContextClass *) pen_parent_class)->root_handler;
 396         if (parent_root_handler) {
 397             ret = parent_root_handler(ec, event);
 398         }
 399     }
 400
 401     return ret;
 402 }
 403
 404 /**
 405  * Handle mouse button press event.
 406  */
 407 static gint pen_handle_button_press(SPPenContext *const pc, GdkEventButton const &bevent)
 408 {
 409     if (pc->events_disabled) {
 410         // skip event processing if events are disabled
 411         return FALSE;
 412     }
 413
 414     SPDrawContext * const dc = SP_DRAW_CONTEXT(pc);
 415     SPDesktop * const desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 416     NR::Point const event_w(bevent.x, bevent.y);
 417     NR::Point const event_dt(desktop->w2d(event_w));
 418     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 419
 420     gint ret = FALSE;
 421     if (bevent.button == 1 && !event_context->space_panning
 422         // make sure this is not the last click for a waiting LPE (otherwise we want to finish the path)
 423         && pc->expecting_clicks_for_LPE != 1) {
 424
 425         if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 426             return TRUE;
 427         }
 428
 429         if (!pc->grab ) {
 430             /* Grab mouse, so release will not pass unnoticed */
 431             pc->grab = SP_CANVAS_ITEM(desktop->acetate);
 432             sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK   |
 433                                             GDK_BUTTON_RELEASE_MASK |
 434                                             GDK_POINTER_MOTION_MASK  ),
 435                                 NULL, bevent.time);
 436         }
 437
 438         pen_drag_origin_w = event_w;
 439         pen_within_tolerance = true;
 440
 441         /* Test whether we hit any anchor. */
 442         SPDrawAnchor * const anchor = spdc_test_inside(pc, event_w);
 443
 444         switch (pc->mode) {
 445             case SP_PEN_CONTEXT_MODE_CLICK:
 446                 /* In click mode we add point on release */
 447                 switch (pc->state) {
 448                     case SP_PEN_CONTEXT_POINT:
 449                     case SP_PEN_CONTEXT_CONTROL:
 450                     case SP_PEN_CONTEXT_CLOSE:
 451                         break;
 452                     case SP_PEN_CONTEXT_STOP:
 453                         /* This is allowed, if we just cancelled curve */
 454                         pc->state = SP_PEN_CONTEXT_POINT;
 455                         break;
 456                     default:
 457                         break;
 458                 }
 459                 break;
 460             case SP_PEN_CONTEXT_MODE_DRAG:
 461                 switch (pc->state) {
 462                     case SP_PEN_CONTEXT_STOP:
 463                         /* This is allowed, if we just cancelled curve */
 464                     case SP_PEN_CONTEXT_POINT:
 465                         if (pc->npoints == 0) {
 466
 467                             if (bevent.state & GDK_CONTROL_MASK) {
 468                                 spdc_create_single_dot(event_context, event_dt, "tools.freehand.pen", bevent.state);
 469                                 ret = TRUE;
 470                                 break;
 471                             }
 472
 473                             // TODO: Perhaps it would be nicer to rearrange the following case
 474                             // distinction so that the case of a waiting LPE is treated separately
 475
 476                             /* Set start anchor */
 477                             pc->sa = anchor;
 478                             NR::Point p;
 479                             if (anchor && !sp_pen_context_has_waiting_LPE(pc)) {
 480                                 /* Adjust point to anchor if needed; if we have a waiting LPE, we need
 481                                    a fresh path to be created so don't continue an existing one */
 482                                 p = anchor->dp;
 483                                 desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Continuing selected path"));
 484                             } else {
 485                                 // This is the first click of a new curve; deselect item so that
 486                                 // this curve is not combined with it (unless it is drawn from its
 487                                 // anchor, which is handled by the sibling branch above)
 488                                 Inkscape::Selection * const selection = sp_desktop_selection(desktop);
 489                                 if (!(bevent.state & GDK_SHIFT_MASK) || sp_pen_context_has_waiting_LPE(pc)) {
 490                                     /* if we have a waiting LPE, we need a fresh path to be created
 491                                        so don't append to an existing one */
 492                                     selection->clear();
 493                                     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Creating new path"));
 494                                 } else if (selection->singleItem() && SP_IS_PATH(selection->singleItem())) {
 495                                     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Appending to selected path"));
 496                                 }
 497
 498                                 /* Create green anchor */
 499                                 p = event_dt;
 500                                 if (!pc->polylines_paraxial) {
 501                                     // only snap the starting point if we're not in horizontal/vertical mode
 502                                     // because otherwise it gets shifted; TODO: why do we snap here at all??
 503                                     spdc_endpoint_snap(pc, p, bevent.state);
 504                                 }
 505                                 pc->green_anchor = sp_draw_anchor_new(pc, pc->green_curve, TRUE, p);
 506                             }
 507                             spdc_pen_set_initial_point(pc, p);
 508                         } else {
 509
 510                             /* Set end anchor */
 511                             pc->ea = anchor;
 512                             NR::Point p;
 513                             if (anchor) {
 514                                 p = anchor->dp;
 515                                 // we hit an anchor, will finish the curve (either with or without closing)
 516                                 // in release handler
 517                                 pc->state = SP_PEN_CONTEXT_CLOSE;
 518
 519                                 if (pc->green_anchor && pc->green_anchor->active) {
 520                                     // we clicked on the current curve start, so close it even if
 521                                     // we drag a handle away from it
 522                                     dc->green_closed = TRUE;
 523                                 }
 524                                 ret = TRUE;
 525                                 break;
 526
 527                             } else {
 528                                 p = event_dt;
 529                                 spdc_endpoint_snap(pc, p, bevent.state); /* Snap node only if not hitting anchor. */
 530                                 spdc_pen_set_subsequent_point(pc, p, true);
 531                                 if (pc->polylines_only) {
 532                                     spdc_pen_finish_segment(pc, p, bevent.state);
 533                                 }
 534                             }
 535                         }
 536
 537                         pc->state = pc->polylines_only ? SP_PEN_CONTEXT_POINT : SP_PEN_CONTEXT_CONTROL;
 538                         ret = TRUE;
 539                         break;
 540                     case SP_PEN_CONTEXT_CONTROL:
 541                         g_warning("Button down in CONTROL state");
 542                         break;
 543                     case SP_PEN_CONTEXT_CLOSE:
 544                         g_warning("Button down in CLOSE state");
 545                         break;
 546                     default:
 547                         break;
 548                 }
 549                 break;
 550             default:
 551                 break;
 552         }
 553     } 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
 554         if (pc->npoints != 0) {
 555
 556             spdc_pen_finish_segment(pc, event_dt, bevent.state);
 557             if (pc->green_closed) {
 558                 // finishing at the start anchor, close curve
 559                 spdc_pen_finish(pc, TRUE);
 560             } else {
 561                 // finishing at some other anchor, finish curve but not close
 562                 spdc_pen_finish(pc, FALSE);
 563             }
 564
 565             ret = TRUE;
 566         }
 567     }
 568
 569     if (pc->expecting_clicks_for_LPE > 0) {
 570         --pc->expecting_clicks_for_LPE;
 571     }
 572
 573     return ret;
 574 }
 575
 576 /**
 577  * Handle motion_notify event.
 578  */
 579 static gint
 580 pen_handle_motion_notify(SPPenContext *const pc, GdkEventMotion const &mevent)
 581 {
 582     gint ret = FALSE;
 583
 584     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 585     SPDesktop * const dt = SP_EVENT_CONTEXT_DESKTOP(event_context);
 586
 587     if (event_context->space_panning || mevent.state & GDK_BUTTON2_MASK || mevent.state & GDK_BUTTON3_MASK) {
 588         // allow scrolling
 589         return FALSE;
 590     }
 591
 592     if (pc->events_disabled) {
 593         // skip motion events if pen events are disabled
 594         return FALSE;
 595     }
 596
 597     NR::Point const event_w(mevent.x,
 598                             mevent.y);
 599     if (pen_within_tolerance) {
 600         gint const tolerance = prefs_get_int_attribute_limited("options.dragtolerance",
 601                                                                "value", 0, 0, 100);
 602         if ( NR::LInfty( event_w - pen_drag_origin_w ) < tolerance ) {
 603             return FALSE;   // Do not drag if we're within tolerance from origin.
 604         }
 605     }
 606     // Once the user has moved farther than tolerance from the original location
 607     // (indicating they intend to move the object, not click), then always process the
 608     // motion notify coordinates as given (no snapping back to origin)
 609     pen_within_tolerance = false;
 610
 611     /* Find desktop coordinates */
 612     NR::Point p = dt->w2d(event_w);
 613
 614     /* Test, whether we hit any anchor */
 615     SPDrawAnchor *anchor = spdc_test_inside(pc, event_w);
 616
 617     switch (pc->mode) {
 618         case SP_PEN_CONTEXT_MODE_CLICK:
 619             switch (pc->state) {
 620                 case SP_PEN_CONTEXT_POINT:
 621                     if ( pc->npoints != 0 ) {
 622                         /* Only set point, if we are already appending */
 623                         spdc_endpoint_snap(pc, p, mevent.state);
 624                         spdc_pen_set_subsequent_point(pc, p, true);
 625                         ret = TRUE;
 626                     }
 627                     break;
 628                 case SP_PEN_CONTEXT_CONTROL:
 629                 case SP_PEN_CONTEXT_CLOSE:
 630                     /* Placing controls is last operation in CLOSE state */
 631                     spdc_endpoint_snap(pc, p, mevent.state);
 632                     spdc_pen_set_ctrl(pc, p, mevent.state);
 633                     ret = TRUE;
 634                     break;
 635                 case SP_PEN_CONTEXT_STOP:
 636                     /* This is perfectly valid */
 637                     break;
 638                 default:
 639                     break;
 640             }
 641             break;
 642         case SP_PEN_CONTEXT_MODE_DRAG:
 643             switch (pc->state) {
 644                 case SP_PEN_CONTEXT_POINT:
 645                     if ( pc->npoints > 0 ) {
 646                         /* Only set point, if we are already appending */
 647
 648                         if (!anchor) {   /* Snap node only if not hitting anchor */
 649                             spdc_endpoint_snap(pc, p, mevent.state);
 650                         }
 651
 652                         spdc_pen_set_subsequent_point(pc, p, !anchor, mevent.state);
 653
 654                         if (anchor && !pc->anchor_statusbar) {
 655                             pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to close and finish the path."));
 656                             pc->anchor_statusbar = true;
 657                         } else if (!anchor && pc->anchor_statusbar) {
 658                             pc->_message_context->clear();
 659                             pc->anchor_statusbar = false;
 660                         }
 661
 662                         ret = TRUE;
 663                     } else {
 664                         if (anchor && !pc->anchor_statusbar) {
 665                             pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Click</b> or <b>click and drag</b> to continue the path from this point."));
 666                             pc->anchor_statusbar = true;
 667                         } else if (!anchor && pc->anchor_statusbar) {
 668                             pc->_message_context->clear();
 669                             pc->anchor_statusbar = false;
 670                         }
 671                     }
 672                     break;
 673                 case SP_PEN_CONTEXT_CONTROL:
 674                 case SP_PEN_CONTEXT_CLOSE:
 675                     /* Placing controls is last operation in CLOSE state */
 676
 677                     // snap the handle
 678                     spdc_endpoint_snap_handle(pc, p, mevent.state);
 679
 680                     if (!pc->polylines_only) {
 681                         spdc_pen_set_ctrl(pc, p, mevent.state);
 682                     } else {
 683                         spdc_pen_set_ctrl(pc, pc->p[1], mevent.state);
 684                     }
 685                     gobble_motion_events(GDK_BUTTON1_MASK);
 686                     ret = TRUE;
 687                     break;
 688                 case SP_PEN_CONTEXT_STOP:
 689                     /* This is perfectly valid */
 690                     break;
 691                 default:
 692                     break;
 693             }
 694             break;
 695         default:
 696             break;
 697     }
 698     return ret;
 699 }
 700
 701 /**
 702  * Handle mouse button release event.
 703  */
 704 static gint
 705 pen_handle_button_release(SPPenContext *const pc, GdkEventButton const &revent)
 706 {
 707     if (pc->events_disabled) {
 708         // skip event processing if events are disabled
 709         return FALSE;
 710     }
 711
 712     gint ret = FALSE;
 713     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 714     if ( revent.button == 1  && !event_context->space_panning) {
 715
 716         SPDrawContext *dc = SP_DRAW_CONTEXT (pc);
 717
 718         NR::Point const event_w(revent.x,
 719                                 revent.y);
 720         /* Find desktop coordinates */
 721         NR::Point p = pc->desktop->w2d(event_w);
 722
 723         /* Test whether we hit any anchor. */
 724         SPDrawAnchor *anchor = spdc_test_inside(pc, event_w);
 725
 726         switch (pc->mode) {
 727             case SP_PEN_CONTEXT_MODE_CLICK:
 728                 switch (pc->state) {
 729                     case SP_PEN_CONTEXT_POINT:
 730                         if ( pc->npoints == 0 ) {
 731                             /* Start new thread only with button release */
 732                             if (anchor) {
 733                                 p = anchor->dp;
 734                             }
 735                             pc->sa = anchor;
 736                             spdc_pen_set_initial_point(pc, p);
 737                         } else {
 738                             /* Set end anchor here */
 739                             pc->ea = anchor;
 740                             if (anchor) {
 741                                 p = anchor->dp;
 742                             }
 743                         }
 744                         pc->state = SP_PEN_CONTEXT_CONTROL;
 745                         ret = TRUE;
 746                         break;
 747                     case SP_PEN_CONTEXT_CONTROL:
 748                         /* End current segment */
 749                         spdc_endpoint_snap(pc, p, revent.state);
 750                         spdc_pen_finish_segment(pc, p, revent.state);
 751                         pc->state = SP_PEN_CONTEXT_POINT;
 752                         ret = TRUE;
 753                         break;
 754                     case SP_PEN_CONTEXT_CLOSE:
 755                         /* End current segment */
 756                         if (!anchor) {   /* Snap node only if not hitting anchor */
 757                             spdc_endpoint_snap(pc, p, revent.state);
 758                         }
 759                         spdc_pen_finish_segment(pc, p, revent.state);
 760                         spdc_pen_finish(pc, TRUE);
 761                         pc->state = SP_PEN_CONTEXT_POINT;
 762                         ret = TRUE;
 763                         break;
 764                     case SP_PEN_CONTEXT_STOP:
 765                         /* This is allowed, if we just cancelled curve */
 766                         pc->state = SP_PEN_CONTEXT_POINT;
 767                         ret = TRUE;
 768                         break;
 769                     default:
 770                         break;
 771                 }
 772                 break;
 773             case SP_PEN_CONTEXT_MODE_DRAG:
 774                 switch (pc->state) {
 775                     case SP_PEN_CONTEXT_POINT:
 776                     case SP_PEN_CONTEXT_CONTROL:
 777                         if (!pc->polylines_only) {
 778                             spdc_endpoint_snap(pc, p, revent.state);
 779                             spdc_pen_finish_segment(pc, p, revent.state);
 780                         }
 781                         break;
 782                     case SP_PEN_CONTEXT_CLOSE:
 783                         spdc_endpoint_snap(pc, p, revent.state);
 784                         spdc_pen_finish_segment(pc, p, revent.state);
 785                         if (pc->green_closed) {
 786                             // finishing at the start anchor, close curve
 787                             spdc_pen_finish(pc, TRUE);
 788                         } else {
 789                             // finishing at some other anchor, finish curve but not close
 790                             spdc_pen_finish(pc, FALSE);
 791                         }
 792                         break;
 793                     case SP_PEN_CONTEXT_STOP:
 794                         /* This is allowed, if we just cancelled curve */
 795                         break;
 796                     default:
 797                         break;
 798                 }
 799                 pc->state = SP_PEN_CONTEXT_POINT;
 800                 ret = TRUE;
 801                 break;
 802             default:
 803                 break;
 804         }
 805
 806         if (pc->grab) {
 807             /* Release grab now */
 808             sp_canvas_item_ungrab(pc->grab, revent.time);
 809             pc->grab = NULL;
 810         }
 811
 812         ret = TRUE;
 813
 814         dc->green_closed = FALSE;
 815     }
 816
 817     // TODO: can we be sure that the path was created correctly?
 818     // TODO: should we offer an option to collect the clicks in a list?
 819     if (pc->expecting_clicks_for_LPE == 0 && sp_pen_context_has_waiting_LPE(pc)) {
 820         sp_pen_context_set_polyline_mode(pc);
 821
 822         SPEventContext *ec = SP_EVENT_CONTEXT(pc);
 823         Inkscape::Selection *selection = sp_desktop_selection (ec->desktop);
 824
 825         if (pc->waiting_LPE) {
 826             // we have an already created LPE waiting for a path
 827             pc->waiting_LPE->acceptParamPath(SP_PATH(selection->singleItem()));
 828             selection->add(SP_OBJECT(pc->waiting_item));
 829             pc->waiting_LPE = NULL;
 830         } else {
 831             // the case that we need to create a new LPE and apply it to the just-drawn path is
 832             // handled in spdc_check_for_and_apply_waiting_LPE() in draw-context.cpp
 833         }
 834     }
 835
 836     return ret;
 837 }
 838
 839 static gint
 840 pen_handle_2button_press(SPPenContext *const pc, GdkEventButton const &bevent)
 841 {
 842     gint ret = FALSE;
 843     if (pc->npoints != 0 && bevent.button != 2) {
 844         spdc_pen_finish(pc, FALSE);
 845         ret = TRUE;
 846     }
 847     return ret;
 848 }
 849
 850 void
 851 pen_redraw_all (SPPenContext *const pc)
 852 {
 853     // green
 854     if (pc->green_bpaths) {
 855         // remove old piecewise green canvasitems
 856         while (pc->green_bpaths) {
 857             gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
 858             pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
 859         }
 860         // one canvas bpath for all of green_curve
 861         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), pc->green_curve);
 862         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 863         sp_canvas_bpath_set_fill(SP_CANVAS_BPATH(cshape), 0, SP_WIND_RULE_NONZERO);
 864
 865         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
 866     }
 867
 868     if (pc->green_anchor)
 869         SP_CTRL(pc->green_anchor->ctrl)->moveto(pc->green_anchor->dp);
 870
 871     pc->red_curve->reset();
 872     pc->red_curve->moveto(pc->p[0]);
 873     pc->red_curve->curveto(pc->p[1], pc->p[2], pc->p[3]);
 874     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 875
 876     // handles
 877     if (pc->p[0] != pc->p[1]) {
 878         SP_CTRL(pc->c1)->moveto(pc->p[1]);
 879         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[0], pc->p[1]);
 880         sp_canvas_item_show (pc->c1);
 881         sp_canvas_item_show (pc->cl1);
 882     } else {
 883         sp_canvas_item_hide (pc->c1);
 884         sp_canvas_item_hide (pc->cl1);
 885     }
 886
 887     Geom::Curve const * last_seg = pc->green_curve->last_segment();
 888     if (last_seg) {
 889         Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>( last_seg );
 890         if ( cubic &&
 891              (*cubic)[2] != to_2geom(pc->p[0]) )
 892         {
 893             NR::Point p2 = (*cubic)[2];
 894             SP_CTRL(pc->c0)->moveto(p2);
 895             sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl0), p2, pc->p[0]);
 896             sp_canvas_item_show (pc->c0);
 897             sp_canvas_item_show (pc->cl0);
 898         } else {
 899             sp_canvas_item_hide (pc->c0);
 900             sp_canvas_item_hide (pc->cl0);
 901         }
 902     }
 903 }
 904
 905 void
 906 pen_lastpoint_move (SPPenContext *const pc, gdouble x, gdouble y)
 907 {
 908     if (pc->npoints != 5)
 909         return;
 910
 911     // green
 912     if (!pc->green_curve->is_empty()) {
 913         pc->green_curve->last_point_additive_move( Geom::Point(x,y) );
 914     } else {
 915         // start anchor too
 916         if (pc->green_anchor) {
 917             pc->green_anchor->dp += NR::Point(x, y);
 918         }
 919     }
 920
 921     // red
 922     pc->p[0] += NR::Point(x, y);
 923     pc->p[1] += NR::Point(x, y);
 924     pen_redraw_all(pc);
 925 }
 926
 927 void
 928 pen_lastpoint_move_screen (SPPenContext *const pc, gdouble x, gdouble y)
 929 {
 930     pen_lastpoint_move (pc, x / pc->desktop->current_zoom(), y / pc->desktop->current_zoom());
 931 }
 932
 933 void
 934 pen_lastpoint_tocurve (SPPenContext *const pc)
 935 {
 936     if (pc->npoints != 5)
 937         return;
 938
 939     Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>( pc->green_curve->last_segment() );
 940     if ( cubic ) {
 941         pc->p[1] = pc->p[0] + (NR::Point)( (*cubic)[3] - (*cubic)[2] );
 942     } else {
 943         pc->p[1] = pc->p[0] + (1./3)*(pc->p[3] - pc->p[0]);
 944     }
 945
 946     pen_redraw_all(pc);
 947 }
 948
 949 void
 950 pen_lastpoint_toline (SPPenContext *const pc)
 951 {
 952     if (pc->npoints != 5)
 953         return;
 954
 955     pc->p[1] = pc->p[0];
 956
 957     pen_redraw_all(pc);
 958 }
 959
 960
 961 static gint
 962 pen_handle_key_press(SPPenContext *const pc, GdkEvent *event)
 963 {
 964     gint ret = FALSE;
 965     gdouble const nudge = prefs_get_double_attribute_limited("options.nudgedistance", "value", 2, 0, 1000); // in px
 966
 967     switch (get_group0_keyval (&event->key)) {
 968
 969         case GDK_Left: // move last point left
 970         case GDK_KP_Left:
 971         case GDK_KP_4:
 972             if (!MOD__CTRL) { // not ctrl
 973                 if (MOD__ALT) { // alt
 974                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, -10, 0); // shift
 975                     else pen_lastpoint_move_screen(pc, -1, 0); // no shift
 976                 }
 977                 else { // no alt
 978                     if (MOD__SHIFT) pen_lastpoint_move(pc, -10*nudge, 0); // shift
 979                     else pen_lastpoint_move(pc, -nudge, 0); // no shift
 980                 }
 981                 ret = TRUE;
 982             }
 983             break;
 984         case GDK_Up: // move last point up
 985         case GDK_KP_Up:
 986         case GDK_KP_8:
 987             if (!MOD__CTRL) { // not ctrl
 988                 if (MOD__ALT) { // alt
 989                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 0, 10); // shift
 990                     else pen_lastpoint_move_screen(pc, 0, 1); // no shift
 991                 }
 992                 else { // no alt
 993                     if (MOD__SHIFT) pen_lastpoint_move(pc, 0, 10*nudge); // shift
 994                     else pen_lastpoint_move(pc, 0, nudge); // no shift
 995                 }
 996                 ret = TRUE;
 997             }
 998             break;
 999         case GDK_Right: // move last point right
1000         case GDK_KP_Right:
1001         case GDK_KP_6:
1002             if (!MOD__CTRL) { // not ctrl
1003                 if (MOD__ALT) { // alt
1004                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 10, 0); // shift
1005                     else pen_lastpoint_move_screen(pc, 1, 0); // no shift
1006                 }
1007                 else { // no alt
1008                     if (MOD__SHIFT) pen_lastpoint_move(pc, 10*nudge, 0); // shift
1009                     else pen_lastpoint_move(pc, nudge, 0); // no shift
1010                 }
1011                 ret = TRUE;
1012             }
1013             break;
1014         case GDK_Down: // move last point down
1015         case GDK_KP_Down:
1016         case GDK_KP_2:
1017             if (!MOD__CTRL) { // not ctrl
1018                 if (MOD__ALT) { // alt
1019                     if (MOD__SHIFT) pen_lastpoint_move_screen(pc, 0, -10); // shift
1020                     else pen_lastpoint_move_screen(pc, 0, -1); // no shift
1021                 }
1022                 else { // no alt
1023                     if (MOD__SHIFT) pen_lastpoint_move(pc, 0, -10*nudge); // shift
1024                     else pen_lastpoint_move(pc, 0, -nudge); // no shift
1025                 }
1026                 ret = TRUE;
1027             }
1028             break;
1029
1030         case GDK_P:
1031         case GDK_p:
1032             if (MOD__SHIFT_ONLY) {
1033                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::PARALLEL, 2);
1034                 ret = TRUE;
1035             }
1036             break;
1037
1038         case GDK_C:
1039         case GDK_c:
1040             if (MOD__SHIFT_ONLY) {
1041                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::CIRCLE_3PTS, 3);
1042                 ret = TRUE;
1043             }
1044             break;
1045
1046         case GDK_B:
1047         case GDK_b:
1048             if (MOD__SHIFT_ONLY) {
1049                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::PERP_BISECTOR, 2);
1050                 ret = TRUE;
1051             }
1052             break;
1053
1054         case GDK_A:
1055         case GDK_a:
1056             if (MOD__SHIFT_ONLY) {
1057                 sp_pen_context_wait_for_LPE_mouse_clicks(pc, Inkscape::LivePathEffect::ANGLE_BISECTOR, 3);
1058                 ret = TRUE;
1059             }
1060             break;
1061
1062         case GDK_U:
1063         case GDK_u:
1064             if (MOD__SHIFT_ONLY) {
1065                 pen_lastpoint_tocurve(pc);
1066                 ret = TRUE;
1067             }
1068             break;
1069         case GDK_L:
1070         case GDK_l:
1071             if (MOD__SHIFT_ONLY) {
1072                 pen_lastpoint_toline(pc);
1073                 ret = TRUE;
1074             }
1075             break;
1076
1077         case GDK_Return:
1078         case GDK_KP_Enter:
1079             if (pc->npoints != 0) {
1080                 spdc_pen_finish(pc, FALSE);
1081                 ret = TRUE;
1082             }
1083             break;
1084         case GDK_Escape:
1085             if (pc->npoints != 0) {
1086                 // if drawing, cancel, otherwise pass it up for deselecting
1087                 pen_cancel (pc);
1088                 ret = TRUE;
1089             }
1090             break;
1091         case GDK_z:
1092         case GDK_Z:
1093             if (MOD__CTRL_ONLY && pc->npoints != 0) {
1094                 // if drawing, cancel, otherwise pass it up for undo
1095                 pen_cancel (pc);
1096                 ret = TRUE;
1097             }
1098             break;
1099         case GDK_g:
1100         case GDK_G:
1101             if (MOD__SHIFT_ONLY) {
1102                 sp_selection_to_guides(SP_EVENT_CONTEXT(pc)->desktop);
1103                 ret = true;
1104             }
1105             break;
1106         case GDK_BackSpace:
1107         case GDK_Delete:
1108         case GDK_KP_Delete:
1109             if (pc->green_curve->is_empty()) {
1110                 if (!pc->red_curve->is_empty()) {
1111                     pen_cancel (pc);
1112                     ret = TRUE;
1113                 } else {
1114                     // do nothing; this event should be handled upstream
1115                 }
1116             } else {
1117                 /* Reset red curve */
1118                 pc->red_curve->reset();
1119                 /* Destroy topmost green bpath */
1120                 if (pc->green_bpaths) {
1121                     if (pc->green_bpaths->data)
1122                         gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
1123                     pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
1124                 }
1125                 /* Get last segment */
1126                 if ( pc->green_curve->is_empty() ) {
1127                     g_warning("pen_handle_key_press, case GDK_KP_Delete: Green curve is empty");
1128                     break;
1129                 }
1130                 // The code below assumes that pc->green_curve has only ONE path !
1131                 Geom::Path const & path = pc->green_curve->get_pathvector().back();
1132                 Geom::Curve const * crv = &path.back_default();
1133                 pc->p[0] = crv->initialPoint();
1134                 if ( Geom::CubicBezier const * cubic = dynamic_cast<Geom::CubicBezier const *>(crv)) {
1135                     pc->p[1] = (*cubic)[1];
1136                 } else {
1137                     pc->p[1] = pc->p[0];
1138                 }
1139                 NR::Point const pt(( pc->npoints < 4
1140                                      ? (NR::Point)(crv->finalPoint())
1141                                      : pc->p[3] ));
1142                 pc->npoints = 2;
1143                 pc->green_curve->backspace();
1144                 sp_canvas_item_hide(pc->c0);
1145                 sp_canvas_item_hide(pc->c1);
1146                 sp_canvas_item_hide(pc->cl0);
1147                 sp_canvas_item_hide(pc->cl1);
1148                 pc->state = SP_PEN_CONTEXT_POINT;
1149                 spdc_pen_set_subsequent_point(pc, pt, true);
1150                 ret = TRUE;
1151             }
1152             break;
1153         default:
1154             break;
1155     }
1156     return ret;
1157 }
1158
1159 static void
1160 spdc_reset_colors(SPPenContext *pc)
1161 {
1162     /* Red */
1163     pc->red_curve->reset();
1164     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
1165     /* Blue */
1166     pc->blue_curve->reset();
1167     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->blue_bpath), NULL);
1168     /* Green */
1169     while (pc->green_bpaths) {
1170         gtk_object_destroy(GTK_OBJECT(pc->green_bpaths->data));
1171         pc->green_bpaths = g_slist_remove(pc->green_bpaths, pc->green_bpaths->data);
1172     }
1173     pc->green_curve->reset();
1174     if (pc->green_anchor) {
1175         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
1176     }
1177     pc->sa = NULL;
1178     pc->ea = NULL;
1179     pc->npoints = 0;
1180     pc->red_curve_is_valid = false;
1181 }
1182
1183
1184 static void
1185 spdc_pen_set_initial_point(SPPenContext *const pc, NR::Point const p)
1186 {
1187     g_assert( pc->npoints == 0 );
1188
1189     pc->p[0] = p;
1190     pc->p[1] = p;
1191     pc->npoints = 2;
1192     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
1193
1194     sp_canvas_force_full_redraw_after_interruptions(pc->desktop->canvas, 5);
1195 }
1196
1197 /**
1198  * Show the status message for the current line/curve segment.
1199  * This type of message always shows angle/distance as the last
1200  * two parameters ("angle %3.2f&#176;, distance %s").
1201  */
1202 static void
1203 spdc_pen_set_angle_distance_status_message(SPPenContext *const pc, NR::Point const p, int pc_point_to_compare, gchar const *message)
1204 {
1205     g_assert(pc != NULL);
1206     g_assert((pc_point_to_compare == 0) || (pc_point_to_compare == 3)); // exclude control handles
1207     g_assert(message != NULL);
1208
1209     SPDesktop *desktop = SP_EVENT_CONTEXT(pc)->desktop;
1210     NR::Point rel = p - pc->p[pc_point_to_compare];
1211     GString *dist = SP_PX_TO_METRIC_STRING(NR::L2(rel), desktop->namedview->getDefaultMetric());
1212     double angle = atan2(rel[NR::Y], rel[NR::X]) * 180 / M_PI;
1213     if (prefs_get_int_attribute("options.compassangledisplay", "value", 0) != 0)
1214         angle = angle_to_compass (angle);
1215
1216     pc->_message_context->setF(Inkscape::IMMEDIATE_MESSAGE, message, angle, dist->str);
1217     g_string_free(dist, FALSE);
1218 }
1219
1220 static void
1221 spdc_pen_set_subsequent_point(SPPenContext *const pc, NR::Point const p, bool statusbar, guint status)
1222 {
1223     g_assert( pc->npoints != 0 );
1224     /* todo: Check callers to see whether 2 <= npoints is guaranteed. */
1225
1226     pc->p[2] = p;
1227     pc->p[3] = p;
1228     pc->p[4] = p;
1229     pc->npoints = 5;
1230     pc->red_curve->reset();
1231     bool is_curve;
1232     pc->red_curve->moveto(pc->p[0]);
1233     if (pc->polylines_paraxial && !statusbar) {
1234         // we are drawing horizontal/vertical lines and hit an anchor; draw an L-shaped path
1235         NR::Point intermed = p;
1236         pen_set_to_nearest_horiz_vert(pc, intermed, status);
1237         pc->red_curve->lineto(intermed);
1238         pc->red_curve->lineto(p);
1239         is_curve = false;
1240     } else {
1241         // one of the 'regular' modes
1242         if (pc->p[1] != pc->p[0])
1243         {
1244             pc->red_curve->curveto(pc->p[1], p, p);
1245             is_curve = true;
1246         } else {
1247             pc->red_curve->lineto(p);
1248             is_curve = false;
1249         }
1250     }
1251
1252     sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
1253
1254     if (statusbar) {
1255         gchar *message = is_curve ?
1256             _("<b>Curve segment</b>: angle %3.2f&#176;, distance %s; with <b>Ctrl</b> to snap angle, <b>Enter</b> to finish the path" ):
1257             _("<b>Line segment</b>: angle %3.2f&#176;, distance %s; with <b>Ctrl</b> to snap angle, <b>Enter</b> to finish the path");
1258         spdc_pen_set_angle_distance_status_message(pc, p, 0, message);
1259     }
1260 }
1261
1262 static void
1263 spdc_pen_set_ctrl(SPPenContext *const pc, NR::Point const p, guint const state)
1264 {
1265     sp_canvas_item_show(pc->c1);
1266     sp_canvas_item_show(pc->cl1);
1267
1268     if ( pc->npoints == 2 ) {
1269         pc->p[1] = p;
1270         sp_canvas_item_hide(pc->c0);
1271         sp_canvas_item_hide(pc->cl0);
1272         SP_CTRL(pc->c1)->moveto(pc->p[1]);
1273         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[0], pc->p[1]);
1274
1275         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"));
1276     } else if ( pc->npoints == 5 ) {
1277         pc->p[4] = p;
1278         sp_canvas_item_show(pc->c0);
1279         sp_canvas_item_show(pc->cl0);
1280         bool is_symm = false;
1281         if ( ( ( pc->mode == SP_PEN_CONTEXT_MODE_CLICK ) && ( state & GDK_CONTROL_MASK ) ) ||
1282              ( ( pc->mode == SP_PEN_CONTEXT_MODE_DRAG ) &&  !( state & GDK_SHIFT_MASK  ) ) ) {
1283             NR::Point delta = p - pc->p[3];
1284             pc->p[2] = pc->p[3] - delta;
1285             is_symm = true;
1286             pc->red_curve->reset();
1287             pc->red_curve->moveto(pc->p[0]);
1288             pc->red_curve->curveto(pc->p[1], pc->p[2], pc->p[3]);
1289             sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
1290         }
1291         SP_CTRL(pc->c0)->moveto(pc->p[2]);
1292         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl0), pc->p[3], pc->p[2]);
1293         SP_CTRL(pc->c1)->moveto(pc->p[4]);
1294         sp_ctrlline_set_coords(SP_CTRLLINE(pc->cl1), pc->p[3], pc->p[4]);
1295
1296         gchar *message = is_symm ?
1297             _("<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") :
1298             _("<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");
1299         spdc_pen_set_angle_distance_status_message(pc, p, 3, message);
1300     } else {
1301         g_warning("Something bad happened - npoints is %d", pc->npoints);
1302     }
1303 }
1304
1305 static void
1306 spdc_pen_finish_segment(SPPenContext *const pc, NR::Point const p, guint const state)
1307 {
1308     if (pc->polylines_paraxial) {
1309         pen_last_paraxial_dir = pen_next_paraxial_direction(pc, p, pc->p[0], state);
1310     }
1311     ++pc->num_clicks;
1312
1313     if (!pc->red_curve->is_empty()) {
1314         pc->green_curve->append_continuous(pc->red_curve, 0.0625);
1315         SPCurve *curve = pc->red_curve->copy();
1316         /// \todo fixme:
1317         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), curve);
1318         curve->unref();
1319         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
1320
1321         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
1322
1323         pc->p[0] = pc->p[3];
1324         pc->p[1] = pc->p[4];
1325         pc->npoints = 2;
1326
1327         pc->red_curve->reset();
1328     }
1329 }
1330
1331 static void
1332 spdc_pen_finish(SPPenContext *const pc, gboolean const closed)
1333 {
1334     if (pc->expecting_clicks_for_LPE > 1) {
1335         // don't let the path be finished before we have collected the required number of mouse clicks
1336         return;
1337     }
1338
1339     pc->num_clicks = 0;
1340
1341     pen_disable_events(pc);
1342
1343     SPDesktop *const desktop = pc->desktop;
1344     pc->_message_context->clear();
1345     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Drawing finished"));
1346
1347     pc->red_curve->reset();
1348     spdc_concat_colors_and_flush(pc, closed);
1349     pc->sa = NULL;
1350     pc->ea = NULL;
1351
1352     pc->npoints = 0;
1353     pc->state = SP_PEN_CONTEXT_POINT;
1354
1355     sp_canvas_item_hide(pc->c0);
1356     sp_canvas_item_hide(pc->c1);
1357     sp_canvas_item_hide(pc->cl0);
1358     sp_canvas_item_hide(pc->cl1);
1359
1360     if (pc->green_anchor) {
1361         pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
1362     }
1363
1364
1365     sp_canvas_end_forced_full_redraws(pc->desktop->canvas);
1366
1367     pen_enable_events(pc);
1368 }
1369
1370 static void
1371 pen_disable_events(SPPenContext *const pc) {
1372   pc->events_disabled++;
1373 }
1374
1375 static void
1376 pen_enable_events(SPPenContext *const pc) {
1377   g_return_if_fail(pc->events_disabled != 0);
1378
1379   pc->events_disabled--;
1380 }
1381
1382 void
1383 sp_pen_context_wait_for_LPE_mouse_clicks(SPPenContext *pc, Inkscape::LivePathEffect::EffectType effect_type,
1384                                          unsigned int num_clicks, bool use_polylines)
1385 {
1386     if (effect_type == Inkscape::LivePathEffect::INVALID_LPE)
1387         return;
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 void
1396 sp_pen_context_cancel_waiting_for_LPE(SPPenContext *pc)
1397 {
1398     pc->waiting_LPE_type = Inkscape::LivePathEffect::INVALID_LPE;
1399     pc->expecting_clicks_for_LPE = 0;
1400     sp_pen_context_set_polyline_mode(pc);
1401 }
1402
1403 static int pen_next_paraxial_direction(const SPPenContext *const pc,
1404                                        NR::Point const &pt, NR::Point const &origin, guint state) {
1405     /*
1406      * after the first mouse click we determine whether the mouse pointer is closest to a
1407      * horizontal or vertical segment; for all subsequent mouse clicks, we use the direction
1408      * orthogonal to the last one; pressing Shift toggles the direction
1409      */
1410     if (pc->num_clicks == 0) {
1411         // first mouse click
1412         double dist_h = fabs(pt[NR::X] - origin[NR::X]);
1413         double dist_v = fabs(pt[NR::Y] - origin[NR::Y]);
1414         int ret = (dist_h < dist_v) ? 1 : 0; // 0 = horizontal, 1 = vertical
1415         pen_last_paraxial_dir = (state & GDK_SHIFT_MASK) ? 1 - ret : ret;
1416         return pen_last_paraxial_dir;
1417     } else {
1418         // subsequent mouse click
1419         return (state & GDK_SHIFT_MASK) ? pen_last_paraxial_dir : 1 - pen_last_paraxial_dir;
1420     }
1421 }
1422
1423 void pen_set_to_nearest_horiz_vert(const SPPenContext *const pc, NR::Point &pt, guint const state)
1424 {
1425     NR::Point const &origin = pc->p[0];
1426
1427     int next_dir = pen_next_paraxial_direction(pc, pt, origin, state);
1428
1429     if (next_dir == 0) {
1430         // line is forced to be horizontal
1431         pt[NR::Y] = origin[NR::Y];
1432     } else {
1433         // line is forced to be vertical
1434         pt[NR::X] = origin[NR::X];
1435     }
1436 }
1437
1438 NR::Point pen_get_intermediate_horiz_vert(const SPPenContext *const pc, NR::Point const &pt)
1439 {
1440     NR::Point const &origin = pc->p[0];
1441
1442     if (pen_last_paraxial_dir == 0) {
1443         return NR::Point (origin[NR::X], pt[NR::Y]);
1444     } else {
1445         return NR::Point (pt[NR::X], origin[NR::Y]);
1446     }
1447 }
1448
1449 /*
1450   Local Variables:
1451   mode:c++
1452   c-file-style:"stroustrup"
1453   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1454   indent-tabs-mode:nil
1455   fill-column:99
1456   End:
1457 */
1458 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :