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