src/pencil-context.cpp

   1 /** \file
   2  * Pencil 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
  20 #include "pencil-context.h"
  21 #include "desktop.h"
  22 #include "desktop-handles.h"
  23 #include "selection.h"
  24 #include "draw-anchor.h"
  25 #include "message-stack.h"
  26 #include "message-context.h"
  27 #include "modifier-fns.h"
  28 #include "sp-path.h"
  29 #include "prefs-utils.h"
  30 #include "snap.h"
  31 #include "pixmaps/cursor-pencil.xpm"
  32 #include "pixmaps/cursor-pencil.pixbuf"
  33 #include "display/bezier-utils.h"
  34 #include "display/canvas-bpath.h"
  35 #include <glibmm/i18n.h>
  36 #include "libnr/in-svg-plane.h"
  37 #include "libnr/n-art-bpath.h"
  38 #include "context-fns.h"
  39 #include "sp-namedview.h"
  40
  41 static void sp_pencil_context_class_init(SPPencilContextClass *klass);
  42 static void sp_pencil_context_init(SPPencilContext *pc);
  43 static void sp_pencil_context_setup(SPEventContext *ec);
  44 static void sp_pencil_context_dispose(GObject *object);
  45
  46 static gint sp_pencil_context_root_handler(SPEventContext *event_context, GdkEvent *event);
  47 static gint pencil_handle_button_press(SPPencilContext *const pc, GdkEventButton const &bevent);
  48 static gint pencil_handle_motion_notify(SPPencilContext *const pc, GdkEventMotion const &mevent);
  49 static gint pencil_handle_button_release(SPPencilContext *const pc, GdkEventButton const &revent);
  50 static gint pencil_handle_key_press(SPPencilContext *const pc, guint const keyval, guint const state);
  51
  52 static void spdc_set_startpoint(SPPencilContext *pc, NR::Point const p);
  53 static void spdc_set_endpoint(SPPencilContext *pc, NR::Point const p);
  54 static void spdc_finish_endpoint(SPPencilContext *pc);
  55 static void spdc_add_freehand_point(SPPencilContext *pc, NR::Point p, guint state);
  56 static void fit_and_split(SPPencilContext *pc);
  57
  58
  59 static SPDrawContextClass *pencil_parent_class;
  60
  61 /**
  62  * Register SPPencilContext class with Gdk and return its type number.
  63  */
  64 GType
  65 sp_pencil_context_get_type()
  66 {
  67     static GType type = 0;
  68     if (!type) {
  69         GTypeInfo info = {
  70             sizeof(SPPencilContextClass),
  71             NULL, NULL,
  72             (GClassInitFunc) sp_pencil_context_class_init,
  73             NULL, NULL,
  74             sizeof(SPPencilContext),
  75             4,
  76             (GInstanceInitFunc) sp_pencil_context_init,
  77             NULL,   /* value_table */
  78         };
  79         type = g_type_register_static(SP_TYPE_DRAW_CONTEXT, "SPPencilContext", &info, (GTypeFlags)0);
  80     }
  81     return type;
  82 }
  83
  84 /**
  85  * Initialize SPPencilContext vtable.
  86  */
  87 static void
  88 sp_pencil_context_class_init(SPPencilContextClass *klass)
  89 {
  90     GObjectClass *object_class;
  91     SPEventContextClass *event_context_class;
  92
  93     object_class = (GObjectClass *) klass;
  94     event_context_class = (SPEventContextClass *) klass;
  95
  96     pencil_parent_class = (SPDrawContextClass*)g_type_class_peek_parent(klass);
  97
  98     object_class->dispose = sp_pencil_context_dispose;
  99
 100     event_context_class->setup = sp_pencil_context_setup;
 101     event_context_class->root_handler = sp_pencil_context_root_handler;
 102 }
 103
 104 /**
 105  * Callback to initialize SPPencilContext object.
 106  */
 107 static void
 108 sp_pencil_context_init(SPPencilContext *pc)
 109 {
 110     SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
 111
 112     event_context->cursor_shape = cursor_pencil_xpm;
 113     event_context->cursor_pixbuf = gdk_pixbuf_new_from_inline(
 114             -1,
 115             cursor_pencil_pixbuf,
 116             FALSE,
 117             NULL);
 118     event_context->hot_x = 4;
 119     event_context->hot_y = 4;
 120
 121     pc->npoints = 0;
 122     pc->state = SP_PENCIL_CONTEXT_IDLE;
 123     pc->req_tangent = NR::Point(0, 0);
 124 }
 125
 126 /**
 127  * Callback to setup SPPencilContext object.
 128  */
 129 static void
 130 sp_pencil_context_setup(SPEventContext *ec)
 131 {
 132     if (prefs_get_int_attribute("tools.freehand.pencil", "selcue", 0) != 0) {
 133         ec->enableSelectionCue();
 134     }
 135
 136     if (((SPEventContextClass *) pencil_parent_class)->setup) {
 137         ((SPEventContextClass *) pencil_parent_class)->setup(ec);
 138     }
 139
 140     SPPencilContext *const pc = SP_PENCIL_CONTEXT(ec);
 141     pc->is_drawing = false;
 142
 143     pc->anchor_statusbar = false;
 144 }
 145
 146 static void
 147 sp_pencil_context_dispose(GObject *object)
 148 {
 149     G_OBJECT_CLASS(pencil_parent_class)->dispose(object);
 150 }
 151
 152 /** Snaps new node relative to the previous node. */
 153 static void
 154 spdc_endpoint_snap(SPPencilContext const *pc, NR::Point &p, guint const state)
 155 {
 156     spdc_endpoint_snap_rotation(pc, p, pc->p[0], state);
 157     spdc_endpoint_snap_free(pc, p, state);
 158 }
 159
 160 /**
 161  * Callback for handling all pencil context events.
 162  */
 163 gint
 164 sp_pencil_context_root_handler(SPEventContext *const ec, GdkEvent *event)
 165 {
 166     SPPencilContext *const pc = SP_PENCIL_CONTEXT(ec);
 167
 168     gint ret = FALSE;
 169
 170     switch (event->type) {
 171         case GDK_BUTTON_PRESS:
 172             ret = pencil_handle_button_press(pc, event->button);
 173             break;
 174
 175         case GDK_MOTION_NOTIFY:
 176             ret = pencil_handle_motion_notify(pc, event->motion);
 177             break;
 178
 179         case GDK_BUTTON_RELEASE:
 180             ret = pencil_handle_button_release(pc, event->button);
 181             break;
 182
 183         case GDK_KEY_PRESS:
 184             ret = pencil_handle_key_press(pc, get_group0_keyval (&event->key), event->key.state);
 185             break;
 186
 187         default:
 188             break;
 189     }
 190
 191     if (!ret) {
 192         gint (*const parent_root_handler)(SPEventContext *, GdkEvent *)
 193             = ((SPEventContextClass *) pencil_parent_class)->root_handler;
 194         if (parent_root_handler) {
 195             ret = parent_root_handler(ec, event);
 196         }
 197     }
 198
 199     return ret;
 200 }
 201
 202 static gint
 203 pencil_handle_button_press(SPPencilContext *const pc, GdkEventButton const &bevent)
 204 {
 205     gint ret = FALSE;
 206     if ( bevent.button == 1 ) {
 207
 208         SPDrawContext *dc = SP_DRAW_CONTEXT (pc);
 209         SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
 210         Inkscape::Selection *selection = sp_desktop_selection(desktop);
 211
 212         if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
 213             return TRUE;
 214         }
 215
 216         NR::Point const button_w(bevent.x, bevent.y);
 217
 218         /* Find desktop coordinates */
 219         NR::Point p = pc->desktop->w2d(button_w);
 220
 221         /* Test whether we hit any anchor. */
 222         SPDrawAnchor *anchor = spdc_test_inside(pc, button_w);
 223
 224         switch (pc->state) {
 225             case SP_PENCIL_CONTEXT_ADDLINE:
 226                 /* Current segment will be finished with release */
 227                 ret = TRUE;
 228                 break;
 229             default:
 230                 /* Set first point of sequence */
 231                 if (anchor) {
 232                     p = anchor->dp;
 233                     desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Continuing selected path"));
 234                 } else {
 235
 236                     if (!(bevent.state & GDK_SHIFT_MASK)) {
 237
 238                         // This is the first click of a new curve; deselect item so that
 239                         // this curve is not combined with it (unless it is drawn from its
 240                         // anchor, which is handled by the sibling branch above)
 241                         selection->clear();
 242                         desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Creating new path"));
 243                         SnapManager const &m = desktop->namedview->snap_manager;
 244                         p = m.freeSnap(Inkscape::Snapper::BBOX_POINT | Inkscape::Snapper::SNAP_POINT, p, NULL).getPoint();
 245                     } else if (selection->singleItem() && SP_IS_PATH(selection->singleItem())) {
 246                         desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Appending to selected path"));
 247                     }
 248                 }
 249                 pc->sa = anchor;
 250                 spdc_set_startpoint(pc, p);
 251                 ret = TRUE;
 252                 break;
 253         }
 254
 255         pc->is_drawing = true;
 256     }
 257     return ret;
 258 }
 259
 260 static gint
 261 pencil_handle_motion_notify(SPPencilContext *const pc, GdkEventMotion const &mevent)
 262 {
 263     gint ret = FALSE;
 264     SPDesktop *const dt = pc->desktop;
 265
 266     if (mevent.state & GDK_BUTTON2_MASK || mevent.state & GDK_BUTTON3_MASK) {
 267         // allow middle-button scrolling
 268         return FALSE;
 269     }
 270
 271     if ( ( mevent.state & GDK_BUTTON1_MASK ) && !pc->grab && pc->is_drawing) {
 272         /* Grab mouse, so release will not pass unnoticed */
 273         pc->grab = SP_CANVAS_ITEM(dt->acetate);
 274         sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK   |
 275                                         GDK_BUTTON_RELEASE_MASK |
 276                                         GDK_POINTER_MOTION_MASK  ),
 277                             NULL, mevent.time);
 278     }
 279
 280     /* Find desktop coordinates */
 281     NR::Point p = dt->w2d(NR::Point(mevent.x, mevent.y));
 282
 283     /* Test whether we hit any anchor. */
 284     SPDrawAnchor *anchor = spdc_test_inside(pc, NR::Point(mevent.x, mevent.y));
 285
 286     switch (pc->state) {
 287         case SP_PENCIL_CONTEXT_ADDLINE:
 288             /* Set red endpoint */
 289             if (anchor) {
 290                 p = anchor->dp;
 291             } else {
 292                 spdc_endpoint_snap(pc, p, mevent.state);
 293             }
 294             spdc_set_endpoint(pc, p);
 295             ret = TRUE;
 296             break;
 297         default:
 298             /* We may be idle or already freehand */
 299             if ( mevent.state & GDK_BUTTON1_MASK && pc->is_drawing ) {
 300                 pc->state = SP_PENCIL_CONTEXT_FREEHAND;
 301                 if ( !pc->sa && !pc->green_anchor ) {
 302                     /* Create green anchor */
 303                     pc->green_anchor = sp_draw_anchor_new(pc, pc->green_curve, TRUE, pc->p[0]);
 304                 }
 305                 /** \todo
 306                  * fixme: I am not sure whether we want to snap to anchors
 307                  * in middle of freehand (Lauris)
 308                  */
 309                 if (anchor) {
 310                     p = anchor->dp;
 311                 } else if ((mevent.state & GDK_SHIFT_MASK) == 0) {
 312                     SnapManager const &m = dt->namedview->snap_manager;
 313                     p = m.freeSnap(Inkscape::Snapper::BBOX_POINT | Inkscape::Snapper::SNAP_POINT, p, NULL).getPoint();
 314                 }
 315                 if ( pc->npoints != 0 ) { // buttonpress may have happened before we entered draw context!
 316                     spdc_add_freehand_point(pc, p, mevent.state);
 317                     ret = TRUE;
 318                 }
 319
 320                 if (anchor && !pc->anchor_statusbar) {
 321                     pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Release</b> here to close and finish the path."));
 322                     pc->anchor_statusbar = true;
 323                 } else if (!anchor && pc->anchor_statusbar) {
 324                     pc->_message_context->clear();
 325                     pc->anchor_statusbar = false;
 326                 } else if (!anchor) {
 327                     pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("Drawing a freehand path"));
 328                 }
 329
 330             } else {
 331                 if (anchor && !pc->anchor_statusbar) {
 332                     pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drag</b> to continue the path from this point."));
 333                     pc->anchor_statusbar = true;
 334                 } else if (!anchor && pc->anchor_statusbar) {
 335                     pc->_message_context->clear();
 336                     pc->anchor_statusbar = false;
 337                 }
 338             }
 339             break;
 340     }
 341     return ret;
 342 }
 343
 344 static gint
 345 pencil_handle_button_release(SPPencilContext *const pc, GdkEventButton const &revent)
 346 {
 347     gint ret = FALSE;
 348
 349     if ( revent.button == 1 && pc->is_drawing) {
 350         SPDesktop *const dt = pc->desktop;
 351
 352         pc->is_drawing = false;
 353
 354         /* Find desktop coordinates */
 355         NR::Point p = dt->w2d(NR::Point(revent.x, revent.y));
 356
 357         /* Test whether we hit any anchor. */
 358         SPDrawAnchor *anchor = spdc_test_inside(pc, NR::Point(revent.x,
 359                                                               revent.y));
 360
 361         switch (pc->state) {
 362             case SP_PENCIL_CONTEXT_IDLE:
 363                 /* Releasing button in idle mode means single click */
 364                 /* We have already set up start point/anchor in button_press */
 365                 pc->state = SP_PENCIL_CONTEXT_ADDLINE;
 366                 ret = TRUE;
 367                 break;
 368             case SP_PENCIL_CONTEXT_ADDLINE:
 369                 /* Finish segment now */
 370                 if (anchor) {
 371                     p = anchor->dp;
 372                 } else {
 373                     spdc_endpoint_snap(pc, p, revent.state);
 374                 }
 375                 pc->ea = anchor;
 376                 spdc_set_endpoint(pc, p);
 377                 spdc_finish_endpoint(pc);
 378                 pc->state = SP_PENCIL_CONTEXT_IDLE;
 379                 ret = TRUE;
 380                 break;
 381             case SP_PENCIL_CONTEXT_FREEHAND:
 382                 /* Finish segment now */
 383                 /// \todo fixme: Clean up what follows (Lauris)
 384                 if (anchor) {
 385                     p = anchor->dp;
 386                 }
 387                 pc->ea = anchor;
 388                 /* Write curves to object */
 389
 390                 dt->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Finishing freehand"));
 391
 392                 spdc_concat_colors_and_flush(pc, FALSE);
 393                 pc->sa = NULL;
 394                 pc->ea = NULL;
 395                 if (pc->green_anchor) {
 396                     pc->green_anchor = sp_draw_anchor_destroy(pc->green_anchor);
 397                 }
 398                 pc->state = SP_PENCIL_CONTEXT_IDLE;
 399                 ret = TRUE;
 400                 break;
 401             default:
 402                 break;
 403         }
 404
 405         if (pc->grab) {
 406             /* Release grab now */
 407             sp_canvas_item_ungrab(pc->grab, revent.time);
 408             pc->grab = NULL;
 409         }
 410
 411         pc->grab = NULL;
 412         ret = TRUE;
 413     }
 414     return ret;
 415 }
 416
 417 static gint
 418 pencil_handle_key_press(SPPencilContext *const pc, guint const keyval, guint const state)
 419 {
 420     gint ret = FALSE;
 421     switch (keyval) {
 422         case GDK_Up:
 423         case GDK_Down:
 424         case GDK_KP_Up:
 425         case GDK_KP_Down:
 426             // Prevent the zoom field from activation.
 427             if (!mod_ctrl_only(state)) {
 428                 ret = TRUE;
 429             }
 430             break;
 431         default:
 432             break;
 433     }
 434     return ret;
 435 }
 436
 437 /**
 438  * Reset points and set new starting point.
 439  */
 440 static void
 441 spdc_set_startpoint(SPPencilContext *const pc, NR::Point const p)
 442 {
 443     pc->npoints = 0;
 444     pc->red_curve_is_valid = false;
 445     if (in_svg_plane(p)) {
 446         pc->p[pc->npoints++] = p;
 447     }
 448 }
 449
 450 /**
 451  * Change moving endpoint position.
 452  * <ul>
 453  * <li>Ctrl constrains to moving to H/V direction, snapping in given direction.
 454  * <li>Otherwise we snap freely to whatever attractors are available.
 455  * </ul>
 456  *
 457  * Number of points is (re)set to 2 always, 2nd point is modified.
 458  * We change RED curve.
 459  */
 460 static void
 461 spdc_set_endpoint(SPPencilContext *const pc, NR::Point const p)
 462 {
 463     if (pc->npoints == 0) {
 464         return;
 465         /* May occur if first point wasn't in SVG plane (e.g. weird w2d transform, perhaps from bad
 466          * zoom setting).
 467          */
 468     }
 469     g_return_if_fail( pc->npoints > 0 );
 470
 471     sp_curve_reset(pc->red_curve);
 472     if ( ( p == pc->p[0] )
 473          || !in_svg_plane(p) )
 474     {
 475         pc->npoints = 1;
 476     } else {
 477         pc->p[1] = p;
 478         pc->npoints = 2;
 479
 480         sp_curve_moveto(pc->red_curve, pc->p[0]);
 481         sp_curve_lineto(pc->red_curve, pc->p[1]);
 482         pc->red_curve_is_valid = true;
 483
 484         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 485     }
 486 }
 487
 488 /**
 489  * Finalize addline.
 490  *
 491  * \todo
 492  * fixme: I'd like remove red reset from concat colors (lauris).
 493  * Still not sure, how it will make most sense.
 494  */
 495 static void
 496 spdc_finish_endpoint(SPPencilContext *const pc)
 497 {
 498     if ( ( SP_CURVE_LENGTH(pc->red_curve) != 2 )
 499          || ( SP_CURVE_SEGMENT(pc->red_curve, 0)->c(3) ==
 500               SP_CURVE_SEGMENT(pc->red_curve, 1)->c(3)   ) )
 501     {
 502         sp_curve_reset(pc->red_curve);
 503         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), NULL);
 504     } else {
 505         /* Write curves to object. */
 506         spdc_concat_colors_and_flush(pc, FALSE);
 507         pc->sa = NULL;
 508         pc->ea = NULL;
 509     }
 510 }
 511
 512 static void
 513 spdc_add_freehand_point(SPPencilContext *pc, NR::Point p, guint state)
 514 {
 515     g_assert( pc->npoints > 0 );
 516     g_return_if_fail(unsigned(pc->npoints) < G_N_ELEMENTS(pc->p));
 517
 518     if ( ( p != pc->p[ pc->npoints - 1 ] )
 519          && in_svg_plane(p) )
 520     {
 521         pc->p[pc->npoints++] = p;
 522         fit_and_split(pc);
 523     }
 524 }
 525
 526 static inline double
 527 square(double const x)
 528 {
 529     return x * x;
 530 }
 531
 532 static void
 533 fit_and_split(SPPencilContext *pc)
 534 {
 535     g_assert( pc->npoints > 1 );
 536
 537     double const tolerance_sq = square( NR::expansion(pc->desktop->w2d())
 538                                         * prefs_get_double_attribute_limited("tools.freehand.pencil",
 539                                                                              "tolerance", 10.0, 1.0, 100.0) );
 540
 541     NR::Point b[4];
 542     g_assert(is_zero(pc->req_tangent)
 543              || is_unit_vector(pc->req_tangent));
 544     NR::Point const tHatEnd(0, 0);
 545     int const n_segs = sp_bezier_fit_cubic_full(b, NULL, pc->p, pc->npoints,
 546                                                 pc->req_tangent, tHatEnd, tolerance_sq, 1);
 547     if ( n_segs > 0
 548          && unsigned(pc->npoints) < G_N_ELEMENTS(pc->p) )
 549     {
 550         /* Fit and draw and reset state */
 551         sp_curve_reset(pc->red_curve);
 552         sp_curve_moveto(pc->red_curve, b[0]);
 553         sp_curve_curveto(pc->red_curve, b[1], b[2], b[3]);
 554         sp_canvas_bpath_set_bpath(SP_CANVAS_BPATH(pc->red_bpath), pc->red_curve);
 555         pc->red_curve_is_valid = true;
 556     } else {
 557         /* Fit and draw and copy last point */
 558
 559         g_assert(!sp_curve_empty(pc->red_curve));
 560
 561         /* Set up direction of next curve. */
 562         {
 563             NArtBpath const &last_seg = *sp_curve_last_bpath(pc->red_curve);
 564             pc->p[0] = last_seg.c(3);
 565             pc->npoints = 1;
 566             g_assert( last_seg.code == NR_CURVETO );
 567             /* Relevance: validity of last_seg.c(2). */
 568             NR::Point const req_vec( pc->p[0] - last_seg.c(2) );
 569             pc->req_tangent = ( ( NR::is_zero(req_vec) || !in_svg_plane(req_vec) )
 570                                 ? NR::Point(0, 0)
 571                                 : NR::unit_vector(req_vec) );
 572         }
 573
 574         sp_curve_append_continuous(pc->green_curve, pc->red_curve, 0.0625);
 575         SPCurve *curve = sp_curve_copy(pc->red_curve);
 576
 577         /// \todo fixme:
 578         SPCanvasItem *cshape = sp_canvas_bpath_new(sp_desktop_sketch(pc->desktop), curve);
 579         sp_curve_unref(curve);
 580         sp_canvas_bpath_set_stroke(SP_CANVAS_BPATH(cshape), pc->green_color, 1.0, SP_STROKE_LINEJOIN_MITER, SP_STROKE_LINECAP_BUTT);
 581
 582         pc->green_bpaths = g_slist_prepend(pc->green_bpaths, cshape);
 583
 584         pc->red_curve_is_valid = false;
 585     }
 586 }
 587
 588
 589 /*
 590   Local Variables:
 591   mode:c++
 592   c-file-style:"stroustrup"
 593   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 594   indent-tabs-mode:nil
 595   fill-column:99
 596   End:
 597 */
 598 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :