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
 111     arc_context->item = NULL;
 112
 113     new (&arc_context->sel_changed_connection) sigc::connection();
 114 }
 115
 116 static void sp_arc_context_finish(SPEventContext *ec)
 117 {
 118     SPArcContext *ac = SP_ARC_CONTEXT(ec);
 119         SPDesktop *desktop = ec->desktop;
 120
 121         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), GDK_CURRENT_TIME);
 122         sp_arc_finish(ac);
 123     ac->sel_changed_connection.disconnect();
 124
 125     if (((SPEventContextClass *) parent_class)->finish) {
 126                 ((SPEventContextClass *) parent_class)->finish(ec);
 127         }
 128 }
 129
 130 static void sp_arc_context_dispose(GObject *object)
 131 {
 132     SPEventContext *ec = SP_EVENT_CONTEXT(object);
 133     SPArcContext *ac = SP_ARC_CONTEXT(object);
 134
 135     ec->enableGrDrag(false);
 136
 137     ac->sel_changed_connection.disconnect();
 138     ac->sel_changed_connection.~connection();
 139
 140     delete ec->shape_editor;
 141     ec->shape_editor = NULL;
 142
 143     /* fixme: This is necessary because we do not grab */
 144     if (ac->item) {
 145         sp_arc_finish(ac);
 146     }
 147
 148     delete ac->_message_context;
 149
 150     G_OBJECT_CLASS(parent_class)->dispose(object);
 151 }
 152
 153 /**
 154 \brief  Callback that processes the "changed" signal on the selection;
 155 destroys old and creates new knotholder.
 156 */
 157 void sp_arc_context_selection_changed(Inkscape::Selection * selection, gpointer data)
 158 {
 159     SPArcContext *ac = SP_ARC_CONTEXT(data);
 160     SPEventContext *ec = SP_EVENT_CONTEXT(ac);
 161
 162     ec->shape_editor->unset_item(SH_KNOTHOLDER);
 163     SPItem *item = selection->singleItem();
 164     ec->shape_editor->set_item(item, SH_KNOTHOLDER);
 165 }
 166
 167 static void sp_arc_context_setup(SPEventContext *ec)
 168 {
 169     SPArcContext *ac = SP_ARC_CONTEXT(ec);
 170     Inkscape::Selection *selection = sp_desktop_selection(ec->desktop);
 171
 172     if (((SPEventContextClass *) parent_class)->setup) {
 173         ((SPEventContextClass *) parent_class)->setup(ec);
 174     }
 175
 176     ec->shape_editor = new ShapeEditor(ec->desktop);
 177
 178     SPItem *item = sp_desktop_selection(ec->desktop)->singleItem();
 179     if (item) {
 180         ec->shape_editor->set_item(item, SH_KNOTHOLDER);
 181     }
 182
 183     ac->sel_changed_connection.disconnect();
 184     ac->sel_changed_connection = selection->connectChanged(
 185         sigc::bind(sigc::ptr_fun(&sp_arc_context_selection_changed), (gpointer) ac)
 186         );
 187
 188     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 189     if (prefs->getBool("/tools/shapes/selcue")) {
 190         ec->enableSelectionCue();
 191     }
 192
 193     if (prefs->getBool("/tools/shapes/gradientdrag")) {
 194         ec->enableGrDrag();
 195     }
 196
 197     ac->_message_context = new Inkscape::MessageContext(ec->desktop->messageStack());
 198 }
 199
 200 static gint sp_arc_context_item_handler(SPEventContext *event_context, SPItem *item, GdkEvent *event)
 201 {
 202     SPDesktop *desktop = event_context->desktop;
 203     gint ret = FALSE;
 204
 205     switch (event->type) {
 206         case GDK_BUTTON_PRESS:
 207             if (event->button.button == 1 && !event_context->space_panning) {
 208                 Inkscape::setup_for_drag_start(desktop, event_context, event);
 209                 ret = TRUE;
 210             }
 211             break;
 212             // motion and release are always on root (why?)
 213         default:
 214             break;
 215     }
 216
 217     if (((SPEventContextClass *) parent_class)->item_handler) {
 218         ret = ((SPEventContextClass *) parent_class)->item_handler(event_context, item, event);
 219     }
 220
 221     return ret;
 222 }
 223
 224 static gint sp_arc_context_root_handler(SPEventContext *event_context, GdkEvent *event)
 225 {
 226     static bool dragging;
 227
 228     SPDesktop *desktop = event_context->desktop;
 229     Inkscape::Selection *selection = sp_desktop_selection(desktop);
 230     SPArcContext *ac = SP_ARC_CONTEXT(event_context);
 231     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 232
 233     event_context->tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
 234
 235     gint ret = FALSE;
 236
 237     switch (event->type) {
 238         case GDK_BUTTON_PRESS:
 239             if (event->button.button == 1 && !event_context->space_panning) {
 240
 241                 dragging = true;
 242                 ac->center = Inkscape::setup_for_drag_start(desktop, event_context, event);
 243
 244                 /* Snap center */
 245                 SnapManager &m = desktop->namedview->snap_manager;
 246                 m.setup(desktop);
 247                 m.freeSnapReturnByRef(ac->center, Inkscape::SNAPSOURCE_NODE_HANDLE);
 248
 249                 sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 250                                     GDK_KEY_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
 251                                     GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK,
 252                                     NULL, event->button.time);
 253                 ret = TRUE;
 254             }
 255             break;
 256         case GDK_MOTION_NOTIFY:
 257             if (dragging && (event->motion.state & GDK_BUTTON1_MASK) && !event_context->space_panning) {
 258
 259                 if ( event_context->within_tolerance
 260                      && ( abs( (gint) event->motion.x - event_context->xp ) < event_context->tolerance )
 261                      && ( abs( (gint) event->motion.y - event_context->yp ) < event_context->tolerance ) ) {
 262                     break; // do not drag if we're within tolerance from origin
 263                 }
 264                 // Once the user has moved farther than tolerance from the original location
 265                 // (indicating they intend to draw, not click), then always process the
 266                 // motion notify coordinates as given (no snapping back to origin)
 267                 event_context->within_tolerance = false;
 268
 269                 Geom::Point const motion_w(event->motion.x, event->motion.y);
 270                 Geom::Point motion_dt(desktop->w2d(motion_w));
 271
 272                 sp_arc_drag(ac, motion_dt, event->motion.state);
 273
 274                 gobble_motion_events(GDK_BUTTON1_MASK);
 275
 276                 ret = TRUE;
 277             }
 278             break;
 279         case GDK_BUTTON_RELEASE:
 280             event_context->xp = event_context->yp = 0;
 281             if (event->button.button == 1 && !event_context->space_panning) {
 282                 dragging = false;
 283                 sp_event_context_discard_delayed_snap_event(event_context);
 284                 if (!event_context->within_tolerance) {
 285                     // we've been dragging, finish the arc
 286                         sp_arc_finish(ac);
 287                 } else if (event_context->item_to_select) {
 288                     // no dragging, select clicked item if any
 289                     if (event->button.state & GDK_SHIFT_MASK) {
 290                         selection->toggle(event_context->item_to_select);
 291                     } else {
 292                         selection->set(event_context->item_to_select);
 293                     }
 294                 } else {
 295                     // click in an empty space
 296                     selection->clear();
 297                 }
 298                 event_context->xp = 0;
 299                 event_context->yp = 0;
 300                 event_context->item_to_select = NULL;
 301                 ret = TRUE;
 302             }
 303             sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 304             break;
 305         case GDK_KEY_PRESS:
 306             switch (get_group0_keyval (&event->key)) {
 307                 case GDK_Alt_L:
 308                 case GDK_Alt_R:
 309                 case GDK_Control_L:
 310                 case GDK_Control_R:
 311                 case GDK_Shift_L:
 312                 case GDK_Shift_R:
 313                 case GDK_Meta_L:  // Meta is when you press Shift+Alt (at least on my machine)
 314                 case GDK_Meta_R:
 315                     if (!dragging) {
 316                         sp_event_show_modifier_tip(event_context->defaultMessageContext(), event,
 317                                                    _("<b>Ctrl</b>: make circle or integer-ratio ellipse, snap arc/segment angle"),
 318                                                    _("<b>Shift</b>: draw around the starting point"),
 319                                                    NULL);
 320                     }
 321                     break;
 322                 case GDK_Up:
 323                 case GDK_Down:
 324                 case GDK_KP_Up:
 325                 case GDK_KP_Down:
 326                     // prevent the zoom field from activation
 327                     if (!MOD__CTRL_ONLY)
 328                         ret = TRUE;
 329                     break;
 330                 case GDK_x:
 331                 case GDK_X:
 332                     if (MOD__ALT_ONLY) {
 333                         desktop->setToolboxFocusTo ("altx-arc");
 334                         ret = TRUE;
 335                     }
 336                     break;
 337                 case GDK_Escape:
 338                         if (dragging) {
 339                                 dragging = false;
 340                                 sp_event_context_discard_delayed_snap_event(event_context);
 341                                 // if drawing, cancel, otherwise pass it up for deselecting
 342                                                 sp_arc_cancel(ac);
 343                                                 ret = TRUE;
 344                                         }
 345                         break;
 346                 case GDK_space:
 347                     if (dragging) {
 348                         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate),
 349                                               event->button.time);
 350                         dragging = false;
 351                         sp_event_context_discard_delayed_snap_event(event_context);
 352                         if (!event_context->within_tolerance) {
 353                             // we've been dragging, finish the arc
 354                             sp_arc_finish(ac);
 355                         }
 356                         // do not return true, so that space would work switching to selector
 357                     }
 358                     break;
 359
 360                 default:
 361                     break;
 362             }
 363             break;
 364         case GDK_KEY_RELEASE:
 365             switch (event->key.keyval) {
 366                 case GDK_Alt_L:
 367                 case GDK_Alt_R:
 368                 case GDK_Control_L:
 369                 case GDK_Control_R:
 370                 case GDK_Shift_L:
 371                 case GDK_Shift_R:
 372                 case GDK_Meta_L:  // Meta is when you press Shift+Alt
 373                 case GDK_Meta_R:
 374                     event_context->defaultMessageContext()->clear();
 375                     break;
 376                 default:
 377                     break;
 378             }
 379             break;
 380         default:
 381             break;
 382     }
 383
 384     if (!ret) {
 385         if (((SPEventContextClass *) parent_class)->root_handler) {
 386             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
 387         }
 388     }
 389
 390     return ret;
 391 }
 392
 393 static void sp_arc_drag(SPArcContext *ac, Geom::Point pt, guint state)
 394 {
 395     SPDesktop *desktop = SP_EVENT_CONTEXT(ac)->desktop;
 396
 397     if (!ac->item) {
 398
 399         if (Inkscape::have_viable_layer(desktop, ac->_message_context) == false) {
 400             return;
 401         }
 402
 403         /* Create object */
 404         Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
 405         Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");
 406         repr->setAttribute("sodipodi:type", "arc");
 407
 408         /* Set style */
 409         sp_desktop_apply_style_tool(desktop, repr, "/tools/shapes/arc", false);
 410
 411         ac->item = SP_ITEM(desktop->currentLayer()->appendChildRepr(repr));
 412         Inkscape::GC::release(repr);
 413         ac->item->transform = sp_item_i2doc_affine(SP_ITEM(desktop->currentLayer())).inverse();
 414         ac->item->updateRepr();
 415
 416         sp_canvas_force_full_redraw_after_interruptions(desktop->canvas, 5);
 417     }
 418
 419     bool ctrl_save = false;
 420     if ((state & GDK_MOD1_MASK) && (state & GDK_CONTROL_MASK) && !(state & GDK_SHIFT_MASK)) {
 421         // if Alt is pressed without Shift in addition to Control, temporarily drop the CONTROL mask
 422         // so that the ellipse is not constrained to integer ratios
 423         ctrl_save = true;
 424         state = state ^ GDK_CONTROL_MASK;
 425     }
 426     Geom::Rect r = Inkscape::snap_rectangular_box(desktop, ac->item, pt, ac->center, state);
 427     if (ctrl_save) {
 428         state = state ^ GDK_CONTROL_MASK;
 429     }
 430
 431     Geom::Point dir = r.dimensions() / 2;
 432     if (state & GDK_MOD1_MASK) {
 433         /* With Alt let the ellipse pass through the mouse pointer */
 434         Geom::Point c = r.midpoint();
 435         if (!ctrl_save) {
 436             if (fabs(dir[Geom::X]) > 1E-6 && fabs(dir[Geom::Y]) > 1E-6) {
 437                 Geom::Matrix const i2d (sp_item_i2d_affine (ac->item));
 438                 Geom::Point new_dir = pt * i2d - c;
 439                 new_dir[Geom::X] *= dir[Geom::Y] / dir[Geom::X];
 440                 double lambda = new_dir.length() / dir[Geom::Y];
 441                 r = Geom::Rect (c - lambda*dir, c + lambda*dir);
 442             }
 443         } else {
 444             /* with Alt+Ctrl (without Shift) we generate a perfect circle
 445                with diameter click point <--> mouse pointer */
 446                 double l = dir.length();
 447                 Geom::Point d (l, l);
 448                 r = Geom::Rect (c - d, c + d);
 449         }
 450     }
 451
 452     sp_arc_position_set(SP_ARC(ac->item),
 453                         r.midpoint()[Geom::X], r.midpoint()[Geom::Y],
 454                         r.dimensions()[Geom::X] / 2, r.dimensions()[Geom::Y] / 2);
 455
 456     double rdimx = r.dimensions()[Geom::X];
 457     double rdimy = r.dimensions()[Geom::Y];
 458     GString *xs = SP_PX_TO_METRIC_STRING(rdimx, desktop->namedview->getDefaultMetric());
 459     GString *ys = SP_PX_TO_METRIC_STRING(rdimy, desktop->namedview->getDefaultMetric());
 460     if (state & GDK_CONTROL_MASK) {
 461         int ratio_x, ratio_y;
 462         if (fabs (rdimx) > fabs (rdimy)) {
 463             ratio_x = (int) rint (rdimx / rdimy);
 464             ratio_y = 1;
 465         } else {
 466             ratio_x = 1;
 467             ratio_y = (int) rint (rdimy / rdimx);
 468         }
 469         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);
 470     } else {
 471         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);
 472     }
 473     g_string_free(xs, FALSE);
 474     g_string_free(ys, FALSE);
 475 }
 476
 477 static void sp_arc_finish(SPArcContext *ac)
 478 {
 479     ac->_message_context->clear();
 480
 481     if (ac->item != NULL) {
 482
 483         SPGenericEllipse *ge = SP_GENERICELLIPSE(SP_ARC(ac->item));
 484                 if (ge->rx.computed == 0 || ge->ry.computed == 0) {
 485                         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
 486                         return;
 487                 }
 488
 489         SPDesktop *desktop = SP_EVENT_CONTEXT(ac)->desktop;
 490
 491         SP_OBJECT(ac->item)->updateRepr();
 492
 493         sp_canvas_end_forced_full_redraws(desktop->canvas);
 494
 495         sp_desktop_selection(desktop)->set(ac->item);
 496         sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_ARC,
 497                          _("Create ellipse"));
 498
 499         ac->item = NULL;
 500     }
 501 }
 502
 503 static void sp_arc_cancel(SPArcContext *ac)
 504 {
 505         SPDesktop *desktop = SP_EVENT_CONTEXT(ac)->desktop;
 506
 507         sp_desktop_selection(desktop)->clear();
 508         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), 0);
 509
 510     if (ac->item != NULL) {
 511         SP_OBJECT(ac->item)->deleteObject();
 512         ac->item = NULL;
 513     }
 514
 515     ac->within_tolerance = false;
 516     ac->xp = 0;
 517     ac->yp = 0;
 518     ac->item_to_select = NULL;
 519
 520     sp_canvas_end_forced_full_redraws(desktop->canvas);
 521
 522     sp_document_cancel(sp_desktop_document(desktop));
 523 }
 524
 525
 526 /*
 527   Local Variables:
 528   mode:c++
 529   c-file-style:"stroustrup"
 530   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 531   indent-tabs-mode:nil
 532   fill-column:99
 533   End:
 534 */
 535 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :