src/arc-context.cpp

   1 /** @file
   2  * @brief Ellipse drawing context
   3  */
   4 /* Authors:
   5  *   Mitsuru Oka
   6  *   Lauris Kaplinski <lauris@kaplinski.com>
   7  *   bulia byak <buliabyak@users.sf.net>
   8  *   Johan Engelen <johan@shouraizou.nl>
   9  *
  10  * Copyright (C) 2000-2006 Authors
  11  * Copyright (C) 2000-2001 Ximian, Inc.
  12  *
  13  * Released under GNU GPL, read the file 'COPYING' for more information
  14  */
  15
  16 #define __SP_ARC_CONTEXT_C__
  17
  18 #ifdef HAVE_CONFIG_H
  19 # include <config.h>
  20 #endif
  21 #include <gdk/gdkkeysyms.h>
  22
  23 #include "macros.h"
  24 #include <glibmm/i18n.h>
  25 #include "display/sp-canvas.h"
  26 #include "sp-ellipse.h"
  27 #include "document.h"
  28 #include "sp-namedview.h"
  29 #include "selection.h"
  30 #include "desktop-handles.h"
  31 #include "snap.h"
  32 #include "pixmaps/cursor-ellipse.xpm"
  33 #include "sp-metrics.h"
  34 #include "xml/repr.h"
  35 #include "xml/node-event-vector.h"
  36 #include "object-edit.h"
  37 #include "preferences.h"
  38 #include "message-context.h"
  39 #include "desktop.h"
  40 #include "desktop-style.h"
  41 #include "context-fns.h"
  42 #include "verbs.h"
  43 #include "shape-editor.h"
  44 #include "event-context.h"
  45
  46 #include "arc-context.h"
  47
  48 static void sp_arc_context_class_init(SPArcContextClass *klass);
  49 static void sp_arc_context_init(SPArcContext *arc_context);
  50 static void sp_arc_context_dispose(GObject *object);
  51
  52 static void sp_arc_context_setup(SPEventContext *ec);
  53 static void sp_arc_context_finish(SPEventContext *ec);
  54 static gint sp_arc_context_root_handler(SPEventContext *event_context, GdkEvent *event);
  55 static gint sp_arc_context_item_handler(SPEventContext *event_context, SPItem *item, GdkEvent *event);
  56
  57 static void sp_arc_drag(SPArcContext *ec, Geom::Point pt, guint state);
  58 static void sp_arc_finish(SPArcContext *ec);
  59 static void sp_arc_cancel(SPArcContext *ec);
  60
  61 static SPEventContextClass *parent_class;
  62
  63 GtkType sp_arc_context_get_type()
  64 {
  65     static GType type = 0;
  66     if (!type) {
  67         GTypeInfo info = {
  68             sizeof(SPArcContextClass),
  69             NULL, NULL,
  70             (GClassInitFunc) sp_arc_context_class_init,
  71             NULL, NULL,
  72             sizeof(SPArcContext),
  73             4,
  74             (GInstanceInitFunc) sp_arc_context_init,
  75             NULL,   /* value_table */
  76         };
  77         type = g_type_register_static(SP_TYPE_EVENT_CONTEXT, "SPArcContext", &info, (GTypeFlags) 0);
  78     }
  79     return type;
  80 }
  81
  82 static void sp_arc_context_class_init(SPArcContextClass *klass)
  83 {
  84
  85     GObjectClass *object_class = (GObjectClass *) klass;
  86     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
  87
  88     parent_class = (SPEventContextClass*) g_type_class_peek_parent(klass);
  89
  90     object_class->dispose = sp_arc_context_dispose;
  91
  92     event_context_class->setup = sp_arc_context_setup;
  93     event_context_class->finish = sp_arc_context_finish;
  94     event_context_class->root_handler = sp_arc_context_root_handler;
  95     event_context_class->item_handler = sp_arc_context_item_handler;
  96 }
  97
  98 static void sp_arc_context_init(SPArcContext *arc_context)
  99 {
 100     SPEventContext *event_context = SP_EVENT_CONTEXT(arc_context);
 101
 102     event_context->cursor_shape = cursor_ellipse_xpm;
 103     event_context->hot_x = 4;
 104     event_context->hot_y = 4;
 105     event_context->xp = 0;
 106     event_context->yp = 0;
 107     event_context->tolerance = 0;
 108     event_context->within_tolerance = false;
 109     event_context->item_to_select = NULL;
 110     event_context->tool_url = "/tools/shapes/arc";
 111
 112     arc_context->item = NULL;
 113
 114     new (&arc_context->sel_changed_connection) sigc::connection();
 115 }
 116
 117 static void sp_arc_context_finish(SPEventContext *ec)
 118 {
 119     SPArcContext *ac = SP_ARC_CONTEXT(ec);
 120     SPDesktop *desktop = ec->desktop;
 121
 122     sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), GDK_CURRENT_TIME);
 123     sp_arc_finish(ac);
 124     ac->sel_changed_connection.disconnect();
 125
 126     if (((SPEventContextClass *) parent_class)->finish) {
 127         ((SPEventContextClass *) parent_class)->finish(ec);
 128     }
 129 }
 130
 131 static void sp_arc_context_dispose(GObject *object)
 132 {
 133     SPEventContext *ec = SP_EVENT_CONTEXT(object);
 134     SPArcContext *ac = SP_ARC_CONTEXT(object);
 135
 136     ec->enableGrDrag(false);
 137
 138     ac->sel_changed_connection.disconnect();
 139     ac->sel_changed_connection.~connection();
 140
 141     delete ec->shape_editor;
 142     ec->shape_editor = NULL;
 143
 144     /* fixme: This is necessary because we do not grab */
 145     if (ac->item) {
 146         sp_arc_finish(ac);
 147     }
 148
 149     delete ac->_message_context;
 150
 151     G_OBJECT_CLASS(parent_class)->dispose(object);
 152 }
 153
 154 /**
 155 \brief  Callback that processes the "changed" signal on the selection;
 156 destroys old and creates new knotholder.
 157 */
 158 void sp_arc_context_selection_changed(Inkscape::Selection * selection, gpointer data)
 159 {
 160     SPArcContext *ac = SP_ARC_CONTEXT(data);
 161     SPEventContext *ec = SP_EVENT_CONTEXT(ac);
 162
 163     ec->shape_editor->unset_item(SH_KNOTHOLDER);
 164     SPItem *item = selection->singleItem();
 165     ec->shape_editor->set_item(item, SH_KNOTHOLDER);
 166 }
 167
 168 static void sp_arc_context_setup(SPEventContext *ec)
 169 {
 170     SPArcContext *ac = SP_ARC_CONTEXT(ec);
 171     Inkscape::Selection *selection = sp_desktop_selection(ec->desktop);
 172
 173     if (((SPEventContextClass *) parent_class)->setup) {
 174         ((SPEventContextClass *) parent_class)->setup(ec);
 175     }
 176
 177     ec->shape_editor = new ShapeEditor(ec->desktop);
 178
 179     SPItem *item = sp_desktop_selection(ec->desktop)->singleItem();
 180     if (item) {
 181         ec->shape_editor->set_item(item, SH_KNOTHOLDER);
 182     }
 183
 184     ac->sel_changed_connection.disconnect();
 185     ac->sel_changed_connection = selection->connectChanged(
 186         sigc::bind(sigc::ptr_fun(&sp_arc_context_selection_changed), (gpointer) ac)
 187         );
 188
 189     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 190     if (prefs->getBool("/tools/shapes/selcue")) {
 191         ec->enableSelectionCue();
 192     }
 193
 194     if (prefs->getBool("/tools/shapes/gradientdrag")) {
 195         ec->enableGrDrag();
 196     }
 197
 198     ac->_message_context = new Inkscape::MessageContext(ec->desktop->messageStack());
 199 }
 200
 201 static gint sp_arc_context_item_handler(SPEventContext *event_context, SPItem *item, GdkEvent *event)
 202 {
 203     SPDesktop *desktop = event_context->desktop;
 204     gint ret = FALSE;
 205
 206     switch (event->type) {
 207         case GDK_BUTTON_PRESS:
 208             if (event->button.button == 1 && !event_context->space_panning) {
 209                 Inkscape::setup_for_drag_start(desktop, event_context, event);
 210                 ret = TRUE;
 211             }
 212             break;
 213             // motion and release are always on root (why?)
 214         default:
 215             break;
 216     }
 217
 218     if (((SPEventContextClass *) parent_class)->item_handler) {
 219         ret = ((SPEventContextClass *) parent_class)->item_handler(event_context, item, event);
 220     }
 221
 222     return ret;
 223 }
 224
 225 static gint sp_arc_context_root_handler(SPEventContext *event_context, GdkEvent *event)
 226 {
 227     static bool dragging;
 228
 229     SPDesktop *desktop = event_context->desktop;
 230     Inkscape::Selection *selection = sp_desktop_selection(desktop);
 231     SPArcContext *ac = SP_ARC_CONTEXT(event_context);
 232     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 233
 234     event_context->tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
 235
 236     gint ret = FALSE;
 237
 238     switch (event->type) {
 239         case GDK_BUTTON_PRESS:
 240             if (event->button.button == 1 && !event_context->space_panning) {
 241
 242                 dragging = true;
 243                 ac->center = Inkscape::setup_for_drag_start(desktop, event_context, event);
 244
 245                 /* Snap center */
 246                 SnapManager &m = desktop->namedview->snap_manager;
 247                 m.setup(desktop);
 248                 m.freeSnapReturnByRef(ac->center, Inkscape::SNAPSOURCE_NODE_HANDLE);
 249
 250                 sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 251                                     GDK_KEY_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
 252                                     GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK,
 253                                     NULL, event->button.time);
 254                 ret = TRUE;
 255                 m.unSetup();
 256             }
 257             break;
 258         case GDK_MOTION_NOTIFY:
 259             if (dragging && (event->motion.state & GDK_BUTTON1_MASK) && !event_context->space_panning) {
 260
 261                 if ( event_context->within_tolerance
 262                      && ( abs( (gint) event->motion.x - event_context->xp ) < event_context->tolerance )
 263                      && ( abs( (gint) event->motion.y - event_context->yp ) < event_context->tolerance ) ) {
 264                     break; // do not drag if we're within tolerance from origin
 265                 }
 266                 // Once the user has moved farther than tolerance from the original location
 267                 // (indicating they intend to draw, not click), then always process the
 268                 // motion notify coordinates as given (no snapping back to origin)
 269                 event_context->within_tolerance = false;
 270
 271                 Geom::Point const motion_w(event->motion.x, event->motion.y);
 272                 Geom::Point motion_dt(desktop->w2d(motion_w));
 273
 274                 sp_arc_drag(ac, motion_dt, event->motion.state);
 275
 276                 gobble_motion_events(GDK_BUTTON1_MASK);
 277
 278                 ret = TRUE;
 279             } else if (!sp_event_context_knot_mouseover(ac)){
 280                 SnapManager &m = desktop->namedview->snap_manager;
 281                 m.setup(desktop);
 282
 283                 Geom::Point const motion_w(event->motion.x, event->motion.y);
 284                 Geom::Point motion_dt(desktop->w2d(motion_w));
 285                 m.preSnap(Inkscape::SnapCandidatePoint(motion_dt, Inkscape::SNAPSOURCE_NODE_HANDLE));
 286                 m.unSetup();
 287             }
 288             break;
 289         case GDK_BUTTON_RELEASE:
 290             event_context->xp = event_context->yp = 0;
 291             if (event->button.button == 1 && !event_context->space_panning) {
 292                 dragging = false;
 293                 sp_event_context_discard_delayed_snap_event(event_context);
 294                 if (!event_context->within_tolerance) {
 295                     // we've been dragging, finish the arc
 296                        sp_arc_finish(ac);
 297                 } else if (event_context->item_to_select) {
 298                     // no dragging, select clicked item if any
 299                     if (event->button.state & GDK_SHIFT_MASK) {
 300                         selection->toggle(event_context->item_to_select);
 301                     } else {
 302                         selection->set(event_context->item_to_select);
 303                     }
 304                 } else {
 305                     // click in an empty space
 306                     selection->clear();
 307                 }
 308                 event_context->xp = 0;
 309                 event_context->yp = 0;
 310                 event_context->item_to_select = NULL;
 311                 ret = TRUE;
 312             }
 313             sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 314             break;
 315         case GDK_KEY_PRESS:
 316             switch (get_group0_keyval (&event->key)) {
 317                 case GDK_Alt_L:
 318                 case GDK_Alt_R:
 319                 case GDK_Control_L:
 320                 case GDK_Control_R:
 321                 case GDK_Shift_L:
 322                 case GDK_Shift_R:
 323                 case GDK_Meta_L:  // Meta is when you press Shift+Alt (at least on my machine)
 324                 case GDK_Meta_R:
 325                     if (!dragging) {
 326                         sp_event_show_modifier_tip(event_context->defaultMessageContext(), event,
 327                                                    _("<b>Ctrl</b>: make circle or integer-ratio ellipse, snap arc/segment angle"),
 328                                                    _("<b>Shift</b>: draw around the starting point"),
 329                                                    NULL);
 330                     }
 331                     break;
 332                 case GDK_Up:
 333                 case GDK_Down:
 334                 case GDK_KP_Up:
 335                 case GDK_KP_Down:
 336                     // prevent the zoom field from activation
 337                     if (!MOD__CTRL_ONLY)
 338                         ret = TRUE;
 339                     break;
 340                 case GDK_x:
 341                 case GDK_X:
 342                     if (MOD__ALT_ONLY) {
 343                         desktop->setToolboxFocusTo ("altx-arc");
 344                         ret = TRUE;
 345                     }
 346                     break;
 347                 case GDK_Escape:
 348                     if (dragging) {
 349                         dragging = false;
 350                         sp_event_context_discard_delayed_snap_event(event_context);
 351                         // if drawing, cancel, otherwise pass it up for deselecting
 352                         sp_arc_cancel(ac);
 353                         ret = TRUE;
 354                     }
 355                     break;
 356                 case GDK_space:
 357                     if (dragging) {
 358                         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate),
 359                                               event->button.time);
 360                         dragging = false;
 361                         sp_event_context_discard_delayed_snap_event(event_context);
 362                         if (!event_context->within_tolerance) {
 363                             // we've been dragging, finish the arc
 364                             sp_arc_finish(ac);
 365                         }
 366                         // do not return true, so that space would work switching to selector
 367                     }
 368                     break;
 369
 370                 default:
 371                     break;
 372             }
 373             break;
 374         case GDK_KEY_RELEASE:
 375             switch (event->key.keyval) {
 376                 case GDK_Alt_L:
 377                 case GDK_Alt_R:
 378                 case GDK_Control_L:
 379                 case GDK_Control_R:
 380                 case GDK_Shift_L:
 381                 case GDK_Shift_R:
 382                 case GDK_Meta_L:  // Meta is when you press Shift+Alt
 383                 case GDK_Meta_R:
 384                     event_context->defaultMessageContext()->clear();
 385                     break;
 386                 default:
 387                     break;
 388             }
 389             break;
 390         default:
 391             break;
 392     }
 393
 394     if (!ret) {
 395         if (((SPEventContextClass *) parent_class)->root_handler) {
 396             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
 397         }
 398     }
 399
 400     return ret;
 401 }
 402
 403 static void sp_arc_drag(SPArcContext *ac, Geom::Point pt, guint state)
 404 {
 405     SPDesktop *desktop = SP_EVENT_CONTEXT(ac)->desktop;
 406
 407     if (!ac->item) {
 408
 409         if (Inkscape::have_viable_layer(desktop, ac->_message_context) == false) {
 410             return;
 411         }
 412
 413         /* Create object */
 414         Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
 415         Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");
 416         repr->setAttribute("sodipodi:type", "arc");
 417
 418         /* Set style */
 419         sp_desktop_apply_style_tool(desktop, repr, "/tools/shapes/arc", false);
 420
 421         ac->item = SP_ITEM(desktop->currentLayer()->appendChildRepr(repr));
 422         Inkscape::GC::release(repr);
 423         ac->item->transform = sp_item_i2doc_affine(SP_ITEM(desktop->currentLayer())).inverse();
 424         ac->item->updateRepr();
 425
 426         sp_canvas_force_full_redraw_after_interruptions(desktop->canvas, 5);
 427     }
 428
 429     bool ctrl_save = false;
 430     if ((state & GDK_MOD1_MASK) && (state & GDK_CONTROL_MASK) && !(state & GDK_SHIFT_MASK)) {
 431         // if Alt is pressed without Shift in addition to Control, temporarily drop the CONTROL mask
 432         // so that the ellipse is not constrained to integer ratios
 433         ctrl_save = true;
 434         state = state ^ GDK_CONTROL_MASK;
 435     }
 436     Geom::Rect r = Inkscape::snap_rectangular_box(desktop, ac->item, pt, ac->center, state);
 437     if (ctrl_save) {
 438         state = state ^ GDK_CONTROL_MASK;
 439     }
 440
 441     Geom::Point dir = r.dimensions() / 2;
 442     if (state & GDK_MOD1_MASK) {
 443         /* With Alt let the ellipse pass through the mouse pointer */
 444         Geom::Point c = r.midpoint();
 445         if (!ctrl_save) {
 446             if (fabs(dir[Geom::X]) > 1E-6 && fabs(dir[Geom::Y]) > 1E-6) {
 447                 Geom::Matrix const i2d (sp_item_i2d_affine (ac->item));
 448                 Geom::Point new_dir = pt * i2d - c;
 449                 new_dir[Geom::X] *= dir[Geom::Y] / dir[Geom::X];
 450                 double lambda = new_dir.length() / dir[Geom::Y];
 451                 r = Geom::Rect (c - lambda*dir, c + lambda*dir);
 452             }
 453         } else {
 454             /* with Alt+Ctrl (without Shift) we generate a perfect circle
 455                with diameter click point <--> mouse pointer */
 456                 double l = dir.length();
 457                 Geom::Point d (l, l);
 458                 r = Geom::Rect (c - d, c + d);
 459         }
 460     }
 461
 462     sp_arc_position_set(SP_ARC(ac->item),
 463                         r.midpoint()[Geom::X], r.midpoint()[Geom::Y],
 464                         r.dimensions()[Geom::X] / 2, r.dimensions()[Geom::Y] / 2);
 465
 466     double rdimx = r.dimensions()[Geom::X];
 467     double rdimy = r.dimensions()[Geom::Y];
 468     GString *xs = SP_PX_TO_METRIC_STRING(rdimx, desktop->namedview->getDefaultMetric());
 469     GString *ys = SP_PX_TO_METRIC_STRING(rdimy, desktop->namedview->getDefaultMetric());
 470     if (state & GDK_CONTROL_MASK) {
 471         int ratio_x, ratio_y;
 472         if (fabs (rdimx) > fabs (rdimy)) {
 473             ratio_x = (int) rint (rdimx / rdimy);
 474             ratio_y = 1;
 475         } else {
 476             ratio_x = 1;
 477             ratio_y = (int) rint (rdimy / rdimx);
 478         }
 479         ac->_message_context->setF(Inkscape::IMMEDIATE_MESSAGE, _("<b>Ellipse</b>: %s &#215; %s (constrained to ratio %d:%d); with <b>Shift</b> to draw around the starting point"), xs->str, ys->str, ratio_x, ratio_y);
 480     } else {
 481         ac->_message_context->setF(Inkscape::IMMEDIATE_MESSAGE, _("<b>Ellipse</b>: %s &#215; %s; with <b>Ctrl</b> to make square or integer-ratio ellipse; with <b>Shift</b> to draw around the starting point"), xs->str, ys->str);
 482     }
 483     g_string_free(xs, FALSE);
 484     g_string_free(ys, FALSE);
 485 }
 486
 487 static void sp_arc_finish(SPArcContext *ac)
 488 {
 489     ac->_message_context->clear();
 490
 491     if (ac->item != NULL) {
 492
 493         SPGenericEllipse *ge = SP_GENERICELLIPSE(SP_ARC(ac->item));
 494         if (ge->rx.computed == 0 || ge->ry.computed == 0) {
 495             sp_arc_cancel(ac); // Don't allow the creating of zero sized arc, for example when the start and and point snap to the snap grid point
 496             return;
 497         }
 498
 499         SPDesktop *desktop = SP_EVENT_CONTEXT(ac)->desktop;
 500
 501         SP_OBJECT(ac->item)->updateRepr();
 502
 503         sp_canvas_end_forced_full_redraws(desktop->canvas);
 504
 505         sp_desktop_selection(desktop)->set(ac->item);
 506         sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_ARC,
 507                          _("Create ellipse"));
 508
 509         ac->item = NULL;
 510     }
 511 }
 512
 513 static void sp_arc_cancel(SPArcContext *ac)
 514 {
 515     SPDesktop *desktop = SP_EVENT_CONTEXT(ac)->desktop;
 516
 517     sp_desktop_selection(desktop)->clear();
 518     sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), 0);
 519
 520     if (ac->item != NULL) {
 521         SP_OBJECT(ac->item)->deleteObject();
 522         ac->item = NULL;
 523     }
 524
 525     ac->within_tolerance = false;
 526     ac->xp = 0;
 527     ac->yp = 0;
 528     ac->item_to_select = NULL;
 529
 530     sp_canvas_end_forced_full_redraws(desktop->canvas);
 531
 532     sp_document_cancel(sp_desktop_document(desktop));
 533 }
 534
 535
 536 /*
 537   Local Variables:
 538   mode:c++
 539   c-file-style:"stroustrup"
 540   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 541   indent-tabs-mode:nil
 542   fill-column:99
 543   End:
 544 */
 545 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :