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 gint sp_arc_context_root_handler(SPEventContext *event_context, GdkEvent *event);
  54 static gint sp_arc_context_item_handler(SPEventContext *event_context, SPItem *item, GdkEvent *event);
  55
  56 static void sp_arc_drag(SPArcContext *ec, Geom::Point pt, guint state);
  57 static void sp_arc_finish(SPArcContext *ec);
  58 static void sp_arc_cancel(SPArcContext *ec);
  59
  60 static SPEventContextClass *parent_class;
  61
  62 GtkType sp_arc_context_get_type()
  63 {
  64     static GType type = 0;
  65     if (!type) {
  66         GTypeInfo info = {
  67             sizeof(SPArcContextClass),
  68             NULL, NULL,
  69             (GClassInitFunc) sp_arc_context_class_init,
  70             NULL, NULL,
  71             sizeof(SPArcContext),
  72             4,
  73             (GInstanceInitFunc) sp_arc_context_init,
  74             NULL,   /* value_table */
  75         };
  76         type = g_type_register_static(SP_TYPE_EVENT_CONTEXT, "SPArcContext", &info, (GTypeFlags) 0);
  77     }
  78     return type;
  79 }
  80
  81 static void sp_arc_context_class_init(SPArcContextClass *klass)
  82 {
  83
  84     GObjectClass *object_class = (GObjectClass *) klass;
  85     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
  86
  87     parent_class = (SPEventContextClass*) g_type_class_peek_parent(klass);
  88
  89     object_class->dispose = sp_arc_context_dispose;
  90
  91     event_context_class->setup = sp_arc_context_setup;
  92     event_context_class->root_handler = sp_arc_context_root_handler;
  93     event_context_class->item_handler = sp_arc_context_item_handler;
  94 }
  95
  96 static void sp_arc_context_init(SPArcContext *arc_context)
  97 {
  98     SPEventContext *event_context = SP_EVENT_CONTEXT(arc_context);
  99
 100     event_context->cursor_shape = cursor_ellipse_xpm;
 101     event_context->hot_x = 4;
 102     event_context->hot_y = 4;
 103     event_context->xp = 0;
 104     event_context->yp = 0;
 105     event_context->tolerance = 0;
 106     event_context->within_tolerance = false;
 107     event_context->item_to_select = NULL;
 108
 109     arc_context->item = NULL;
 110
 111     new (&arc_context->sel_changed_connection) sigc::connection();
 112 }
 113
 114 static void sp_arc_context_dispose(GObject *object)
 115 {
 116     SPEventContext *ec = SP_EVENT_CONTEXT(object);
 117     SPArcContext *ac = SP_ARC_CONTEXT(object);
 118
 119     ec->enableGrDrag(false);
 120
 121     ac->sel_changed_connection.disconnect();
 122     ac->sel_changed_connection.~connection();
 123
 124     delete ec->shape_editor;
 125     ec->shape_editor = NULL;
 126
 127     /* fixme: This is necessary because we do not grab */
 128     if (ac->item) {
 129         sp_arc_finish(ac);
 130     }
 131
 132     delete ac->_message_context;
 133
 134     G_OBJECT_CLASS(parent_class)->dispose(object);
 135 }
 136
 137 /**
 138 \brief  Callback that processes the "changed" signal on the selection;
 139 destroys old and creates new knotholder.
 140 */
 141 void sp_arc_context_selection_changed(Inkscape::Selection * selection, gpointer data)
 142 {
 143     SPArcContext *ac = SP_ARC_CONTEXT(data);
 144     SPEventContext *ec = SP_EVENT_CONTEXT(ac);
 145
 146     ec->shape_editor->unset_item(SH_KNOTHOLDER);
 147     SPItem *item = selection->singleItem();
 148     ec->shape_editor->set_item(item, SH_KNOTHOLDER);
 149 }
 150
 151 static void sp_arc_context_setup(SPEventContext *ec)
 152 {
 153     SPArcContext *ac = SP_ARC_CONTEXT(ec);
 154     Inkscape::Selection *selection = sp_desktop_selection(ec->desktop);
 155
 156     if (((SPEventContextClass *) parent_class)->setup) {
 157         ((SPEventContextClass *) parent_class)->setup(ec);
 158     }
 159
 160     ec->shape_editor = new ShapeEditor(ec->desktop);
 161
 162     SPItem *item = sp_desktop_selection(ec->desktop)->singleItem();
 163     if (item) {
 164         ec->shape_editor->set_item(item, SH_KNOTHOLDER);
 165     }
 166
 167     ac->sel_changed_connection.disconnect();
 168     ac->sel_changed_connection = selection->connectChanged(
 169         sigc::bind(sigc::ptr_fun(&sp_arc_context_selection_changed), (gpointer) ac)
 170         );
 171
 172     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 173     if (prefs->getBool("/tools/shapes/selcue")) {
 174         ec->enableSelectionCue();
 175     }
 176
 177     if (prefs->getBool("/tools/shapes/gradientdrag")) {
 178         ec->enableGrDrag();
 179     }
 180
 181     ac->_message_context = new Inkscape::MessageContext(ec->desktop->messageStack());
 182 }
 183
 184 static gint sp_arc_context_item_handler(SPEventContext *event_context, SPItem *item, GdkEvent *event)
 185 {
 186     SPDesktop *desktop = event_context->desktop;
 187     gint ret = FALSE;
 188
 189     switch (event->type) {
 190         case GDK_BUTTON_PRESS:
 191             if (event->button.button == 1 && !event_context->space_panning) {
 192                 Inkscape::setup_for_drag_start(desktop, event_context, event);
 193                 ret = TRUE;
 194             }
 195             break;
 196             // motion and release are always on root (why?)
 197         default:
 198             break;
 199     }
 200
 201     if (((SPEventContextClass *) parent_class)->item_handler) {
 202         ret = ((SPEventContextClass *) parent_class)->item_handler(event_context, item, event);
 203     }
 204
 205     return ret;
 206 }
 207
 208 static gint sp_arc_context_root_handler(SPEventContext *event_context, GdkEvent *event)
 209 {
 210     static bool dragging;
 211
 212     SPDesktop *desktop = event_context->desktop;
 213     Inkscape::Selection *selection = sp_desktop_selection(desktop);
 214     SPArcContext *ac = SP_ARC_CONTEXT(event_context);
 215     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 216
 217     event_context->tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
 218
 219     gint ret = FALSE;
 220
 221     switch (event->type) {
 222         case GDK_BUTTON_PRESS:
 223             if (event->button.button == 1 && !event_context->space_panning) {
 224
 225                 dragging = true;
 226                 ac->center = Inkscape::setup_for_drag_start(desktop, event_context, event);
 227
 228                 /* Snap center */
 229                 SnapManager &m = desktop->namedview->snap_manager;
 230                 m.setup(desktop);
 231                 Geom::Point pt2g = to_2geom(ac->center);
 232                 m.freeSnapReturnByRef(Inkscape::SnapPreferences::SNAPPOINT_NODE, pt2g, Inkscape::SNAPSOURCE_HANDLE);
 233                 ac->center = from_2geom(pt2g);
 234
 235                 sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 236                                     GDK_KEY_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
 237                                     GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK,
 238                                     NULL, event->button.time);
 239                 ret = TRUE;
 240             }
 241             break;
 242         case GDK_MOTION_NOTIFY:
 243             if (dragging && (event->motion.state & GDK_BUTTON1_MASK) && !event_context->space_panning) {
 244
 245                 if ( event_context->within_tolerance
 246                      && ( abs( (gint) event->motion.x - event_context->xp ) < event_context->tolerance )
 247                      && ( abs( (gint) event->motion.y - event_context->yp ) < event_context->tolerance ) ) {
 248                     break; // do not drag if we're within tolerance from origin
 249                 }
 250                 // Once the user has moved farther than tolerance from the original location
 251                 // (indicating they intend to draw, not click), then always process the
 252                 // motion notify coordinates as given (no snapping back to origin)
 253                 event_context->within_tolerance = false;
 254
 255                 Geom::Point const motion_w(event->motion.x, event->motion.y);
 256                 Geom::Point motion_dt(desktop->w2d(motion_w));
 257
 258                 sp_arc_drag(ac, motion_dt, event->motion.state);
 259
 260                 gobble_motion_events(GDK_BUTTON1_MASK);
 261
 262                 ret = TRUE;
 263             }
 264             break;
 265         case GDK_BUTTON_RELEASE:
 266             event_context->xp = event_context->yp = 0;
 267             if (event->button.button == 1 && !event_context->space_panning) {
 268                 dragging = false;
 269                 sp_event_context_discard_delayed_snap_event(event_context);
 270                 if (!event_context->within_tolerance) {
 271                     // we've been dragging, finish the arc
 272                         sp_arc_finish(ac);
 273                 } else if (event_context->item_to_select) {
 274                     // no dragging, select clicked item if any
 275                     if (event->button.state & GDK_SHIFT_MASK) {
 276                         selection->toggle(event_context->item_to_select);
 277                     } else {
 278                         selection->set(event_context->item_to_select);
 279                     }
 280                 } else {
 281                     // click in an empty space
 282                     selection->clear();
 283                 }
 284                 event_context->xp = 0;
 285                 event_context->yp = 0;
 286                 event_context->item_to_select = NULL;
 287                 ret = TRUE;
 288             }
 289             sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 290             break;
 291         case GDK_KEY_PRESS:
 292             switch (get_group0_keyval (&event->key)) {
 293                 case GDK_Alt_L:
 294                 case GDK_Alt_R:
 295                 case GDK_Control_L:
 296                 case GDK_Control_R:
 297                 case GDK_Shift_L:
 298                 case GDK_Shift_R:
 299                 case GDK_Meta_L:  // Meta is when you press Shift+Alt (at least on my machine)
 300                 case GDK_Meta_R:
 301                     if (!dragging) {
 302                         sp_event_show_modifier_tip(event_context->defaultMessageContext(), event,
 303                                                    _("<b>Ctrl</b>: make circle or integer-ratio ellipse, snap arc/segment angle"),
 304                                                    _("<b>Shift</b>: draw around the starting point"),
 305                                                    NULL);
 306                     }
 307                     break;
 308                 case GDK_Up:
 309                 case GDK_Down:
 310                 case GDK_KP_Up:
 311                 case GDK_KP_Down:
 312                     // prevent the zoom field from activation
 313                     if (!MOD__CTRL_ONLY)
 314                         ret = TRUE;
 315                     break;
 316                 case GDK_x:
 317                 case GDK_X:
 318                     if (MOD__ALT_ONLY) {
 319                         desktop->setToolboxFocusTo ("altx-arc");
 320                         ret = TRUE;
 321                     }
 322                     break;
 323                 case GDK_Escape:
 324                         if (dragging) {
 325                                 dragging = false;
 326                                 sp_event_context_discard_delayed_snap_event(event_context);
 327                                 // if drawing, cancel, otherwise pass it up for deselecting
 328                                                 sp_arc_cancel(ac);
 329                                                 ret = TRUE;
 330                                         }
 331                         break;
 332                 case GDK_space:
 333                     if (dragging) {
 334                         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate),
 335                                               event->button.time);
 336                         dragging = false;
 337                         sp_event_context_discard_delayed_snap_event(event_context);
 338                         if (!event_context->within_tolerance) {
 339                             // we've been dragging, finish the arc
 340                             sp_arc_finish(ac);
 341                         }
 342                         // do not return true, so that space would work switching to selector
 343                     }
 344                     break;
 345
 346                 default:
 347                     break;
 348             }
 349             break;
 350         case GDK_KEY_RELEASE:
 351             switch (event->key.keyval) {
 352                 case GDK_Alt_L:
 353                 case GDK_Alt_R:
 354                 case GDK_Control_L:
 355                 case GDK_Control_R:
 356                 case GDK_Shift_L:
 357                 case GDK_Shift_R:
 358                 case GDK_Meta_L:  // Meta is when you press Shift+Alt
 359                 case GDK_Meta_R:
 360                     event_context->defaultMessageContext()->clear();
 361                     break;
 362                 default:
 363                     break;
 364             }
 365             break;
 366         default:
 367             break;
 368     }
 369
 370     if (!ret) {
 371         if (((SPEventContextClass *) parent_class)->root_handler) {
 372             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
 373         }
 374     }
 375
 376     return ret;
 377 }
 378
 379 static void sp_arc_drag(SPArcContext *ac, Geom::Point pt, guint state)
 380 {
 381     SPDesktop *desktop = SP_EVENT_CONTEXT(ac)->desktop;
 382
 383     if (!ac->item) {
 384
 385         if (Inkscape::have_viable_layer(desktop, ac->_message_context) == false) {
 386             return;
 387         }
 388
 389         /* Create object */
 390         Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
 391         Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");
 392         repr->setAttribute("sodipodi:type", "arc");
 393
 394         /* Set style */
 395         sp_desktop_apply_style_tool(desktop, repr, "/tools/shapes/arc", false);
 396
 397         ac->item = SP_ITEM(desktop->currentLayer()->appendChildRepr(repr));
 398         Inkscape::GC::release(repr);
 399         ac->item->transform = sp_item_i2doc_affine(SP_ITEM(desktop->currentLayer())).inverse();
 400         ac->item->updateRepr();
 401
 402         sp_canvas_force_full_redraw_after_interruptions(desktop->canvas, 5);
 403     }
 404
 405     bool ctrl_save = false;
 406     if ((state & GDK_MOD1_MASK) && (state & GDK_CONTROL_MASK) && !(state & GDK_SHIFT_MASK)) {
 407         // if Alt is pressed without Shift in addition to Control, temporarily drop the CONTROL mask
 408         // so that the ellipse is not constrained to integer ratios
 409         ctrl_save = true;
 410         state = state ^ GDK_CONTROL_MASK;
 411     }
 412     Geom::Rect r = Inkscape::snap_rectangular_box(desktop, ac->item, pt, ac->center, state);
 413     if (ctrl_save) {
 414         state = state ^ GDK_CONTROL_MASK;
 415     }
 416
 417     Geom::Point dir = r.dimensions() / 2;
 418     if (state & GDK_MOD1_MASK) {
 419         /* With Alt let the ellipse pass through the mouse pointer */
 420         Geom::Point c = r.midpoint();
 421         if (!ctrl_save) {
 422             if (fabs(dir[Geom::X]) > 1E-6 && fabs(dir[Geom::Y]) > 1E-6) {
 423                 Geom::Matrix const i2d (sp_item_i2d_affine (ac->item));
 424                 Geom::Point new_dir = pt * i2d - c;
 425                 new_dir[Geom::X] *= dir[Geom::Y] / dir[Geom::X];
 426                 double lambda = new_dir.length() / dir[Geom::Y];
 427                 r = Geom::Rect (c - lambda*dir, c + lambda*dir);
 428             }
 429         } else {
 430             /* with Alt+Ctrl (without Shift) we generate a perfect circle
 431                with diameter click point <--> mouse pointer */
 432                 double l = dir.length();
 433                 Geom::Point d (l, l);
 434                 r = Geom::Rect (c - d, c + d);
 435         }
 436     }
 437
 438     sp_arc_position_set(SP_ARC(ac->item),
 439                         r.midpoint()[Geom::X], r.midpoint()[Geom::Y],
 440                         r.dimensions()[Geom::X] / 2, r.dimensions()[Geom::Y] / 2);
 441
 442     double rdimx = r.dimensions()[Geom::X];
 443     double rdimy = r.dimensions()[Geom::Y];
 444     GString *xs = SP_PX_TO_METRIC_STRING(rdimx, desktop->namedview->getDefaultMetric());
 445     GString *ys = SP_PX_TO_METRIC_STRING(rdimy, desktop->namedview->getDefaultMetric());
 446     if (state & GDK_CONTROL_MASK) {
 447         int ratio_x, ratio_y;
 448         if (fabs (rdimx) > fabs (rdimy)) {
 449             ratio_x = (int) rint (rdimx / rdimy);
 450             ratio_y = 1;
 451         } else {
 452             ratio_x = 1;
 453             ratio_y = (int) rint (rdimy / rdimx);
 454         }
 455         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);
 456     } else {
 457         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);
 458     }
 459     g_string_free(xs, FALSE);
 460     g_string_free(ys, FALSE);
 461 }
 462
 463 static void sp_arc_finish(SPArcContext *ac)
 464 {
 465     ac->_message_context->clear();
 466
 467     if (ac->item != NULL) {
 468
 469         SPGenericEllipse *ge = SP_GENERICELLIPSE(SP_ARC(ac->item));
 470                 if (ge->rx.computed == 0 || ge->ry.computed == 0) {
 471                         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
 472                         return;
 473                 }
 474
 475         SPDesktop *desktop = SP_EVENT_CONTEXT(ac)->desktop;
 476
 477         SP_OBJECT(ac->item)->updateRepr();
 478
 479         sp_canvas_end_forced_full_redraws(desktop->canvas);
 480
 481         sp_desktop_selection(desktop)->set(ac->item);
 482         sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_ARC,
 483                          _("Create ellipse"));
 484
 485         ac->item = NULL;
 486     }
 487 }
 488
 489 static void sp_arc_cancel(SPArcContext *ac)
 490 {
 491         SPDesktop *desktop = SP_EVENT_CONTEXT(ac)->desktop;
 492
 493         sp_desktop_selection(desktop)->clear();
 494         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), 0);
 495
 496     if (ac->item != NULL) {
 497         SP_OBJECT(ac->item)->deleteObject();
 498         ac->item = NULL;
 499     }
 500
 501     ac->within_tolerance = false;
 502     ac->xp = 0;
 503     ac->yp = 0;
 504     ac->item_to_select = NULL;
 505
 506     sp_canvas_end_forced_full_redraws(desktop->canvas);
 507
 508     sp_document_cancel(sp_desktop_document(desktop));
 509 }
 510
 511
 512 /*
 513   Local Variables:
 514   mode:c++
 515   c-file-style:"stroustrup"
 516   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 517   indent-tabs-mode:nil
 518   fill-column:99
 519   End:
 520 */
 521 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :