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  *   Abhishek Sharma
  10  *
  11  * Copyright (C) 2000-2006 Authors
  12  * Copyright (C) 2000-2001 Ximian, Inc.
  13  *
  14  * Released under GNU GPL, read the file 'COPYING' for more information
  15  */
  16
  17 #define __SP_ARC_CONTEXT_C__
  18
  19 #ifdef HAVE_CONFIG_H
  20 # include <config.h>
  21 #endif
  22 #include <gdk/gdkkeysyms.h>
  23
  24 #include "macros.h"
  25 #include <glibmm/i18n.h>
  26 #include "display/sp-canvas.h"
  27 #include "sp-ellipse.h"
  28 #include "document.h"
  29 #include "sp-namedview.h"
  30 #include "selection.h"
  31 #include "desktop-handles.h"
  32 #include "snap.h"
  33 #include "pixmaps/cursor-ellipse.xpm"
  34 #include "sp-metrics.h"
  35 #include "xml/repr.h"
  36 #include "xml/node-event-vector.h"
  37 #include "object-edit.h"
  38 #include "preferences.h"
  39 #include "message-context.h"
  40 #include "desktop.h"
  41 #include "desktop-style.h"
  42 #include "context-fns.h"
  43 #include "verbs.h"
  44 #include "shape-editor.h"
  45 #include "event-context.h"
  46
  47 #include "arc-context.h"
  48
  49 using Inkscape::DocumentUndo;
  50
  51 static void sp_arc_context_class_init(SPArcContextClass *klass);
  52 static void sp_arc_context_init(SPArcContext *arc_context);
  53 static void sp_arc_context_dispose(GObject *object);
  54
  55 static void sp_arc_context_setup(SPEventContext *ec);
  56 static void sp_arc_context_finish(SPEventContext *ec);
  57 static gint sp_arc_context_root_handler(SPEventContext *event_context, GdkEvent *event);
  58 static gint sp_arc_context_item_handler(SPEventContext *event_context, SPItem *item, GdkEvent *event);
  59
  60 static void sp_arc_drag(SPArcContext *ec, Geom::Point pt, guint state);
  61 static void sp_arc_finish(SPArcContext *ec);
  62 static void sp_arc_cancel(SPArcContext *ec);
  63
  64 static SPEventContextClass *parent_class;
  65
  66 GtkType sp_arc_context_get_type()
  67 {
  68     static GType type = 0;
  69     if (!type) {
  70         GTypeInfo info = {
  71             sizeof(SPArcContextClass),
  72             NULL, NULL,
  73             (GClassInitFunc) sp_arc_context_class_init,
  74             NULL, NULL,
  75             sizeof(SPArcContext),
  76             4,
  77             (GInstanceInitFunc) sp_arc_context_init,
  78             NULL,   /* value_table */
  79         };
  80         type = g_type_register_static(SP_TYPE_EVENT_CONTEXT, "SPArcContext", &info, (GTypeFlags) 0);
  81     }
  82     return type;
  83 }
  84
  85 static void sp_arc_context_class_init(SPArcContextClass *klass)
  86 {
  87
  88     GObjectClass *object_class = (GObjectClass *) klass;
  89     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
  90
  91     parent_class = (SPEventContextClass*) g_type_class_peek_parent(klass);
  92
  93     object_class->dispose = sp_arc_context_dispose;
  94
  95     event_context_class->setup = sp_arc_context_setup;
  96     event_context_class->finish = sp_arc_context_finish;
  97     event_context_class->root_handler = sp_arc_context_root_handler;
  98     event_context_class->item_handler = sp_arc_context_item_handler;
  99 }
 100
 101 static void sp_arc_context_init(SPArcContext *arc_context)
 102 {
 103     SPEventContext *event_context = SP_EVENT_CONTEXT(arc_context);
 104
 105     event_context->cursor_shape = cursor_ellipse_xpm;
 106     event_context->hot_x = 4;
 107     event_context->hot_y = 4;
 108     event_context->xp = 0;
 109     event_context->yp = 0;
 110     event_context->tolerance = 0;
 111     event_context->within_tolerance = false;
 112     event_context->item_to_select = NULL;
 113     event_context->tool_url = "/tools/shapes/arc";
 114
 115     arc_context->item = NULL;
 116
 117     new (&arc_context->sel_changed_connection) sigc::connection();
 118 }
 119
 120 static void sp_arc_context_finish(SPEventContext *ec)
 121 {
 122     SPArcContext *ac = SP_ARC_CONTEXT(ec);
 123     SPDesktop *desktop = ec->desktop;
 124
 125     sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), GDK_CURRENT_TIME);
 126     sp_arc_finish(ac);
 127     ac->sel_changed_connection.disconnect();
 128
 129     if (((SPEventContextClass *) parent_class)->finish) {
 130         ((SPEventContextClass *) parent_class)->finish(ec);
 131     }
 132 }
 133
 134 static void sp_arc_context_dispose(GObject *object)
 135 {
 136     SPEventContext *ec = SP_EVENT_CONTEXT(object);
 137     SPArcContext *ac = SP_ARC_CONTEXT(object);
 138
 139     ec->enableGrDrag(false);
 140
 141     ac->sel_changed_connection.disconnect();
 142     ac->sel_changed_connection.~connection();
 143
 144     delete ec->shape_editor;
 145     ec->shape_editor = NULL;
 146
 147     /* fixme: This is necessary because we do not grab */
 148     if (ac->item) {
 149         sp_arc_finish(ac);
 150     }
 151
 152     delete ac->_message_context;
 153
 154     G_OBJECT_CLASS(parent_class)->dispose(object);
 155 }
 156
 157 /**
 158 \brief  Callback that processes the "changed" signal on the selection;
 159 destroys old and creates new knotholder.
 160 */
 161 void sp_arc_context_selection_changed(Inkscape::Selection * selection, gpointer data)
 162 {
 163     SPArcContext *ac = SP_ARC_CONTEXT(data);
 164     SPEventContext *ec = SP_EVENT_CONTEXT(ac);
 165
 166     ec->shape_editor->unset_item(SH_KNOTHOLDER);
 167     SPItem *item = selection->singleItem();
 168     ec->shape_editor->set_item(item, SH_KNOTHOLDER);
 169 }
 170
 171 static void sp_arc_context_setup(SPEventContext *ec)
 172 {
 173     SPArcContext *ac = SP_ARC_CONTEXT(ec);
 174     Inkscape::Selection *selection = sp_desktop_selection(ec->desktop);
 175
 176     if (((SPEventContextClass *) parent_class)->setup) {
 177         ((SPEventContextClass *) parent_class)->setup(ec);
 178     }
 179
 180     ec->shape_editor = new ShapeEditor(ec->desktop);
 181
 182     SPItem *item = sp_desktop_selection(ec->desktop)->singleItem();
 183     if (item) {
 184         ec->shape_editor->set_item(item, SH_KNOTHOLDER);
 185     }
 186
 187     ac->sel_changed_connection.disconnect();
 188     ac->sel_changed_connection = selection->connectChanged(
 189         sigc::bind(sigc::ptr_fun(&sp_arc_context_selection_changed), (gpointer) ac)
 190         );
 191
 192     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 193     if (prefs->getBool("/tools/shapes/selcue")) {
 194         ec->enableSelectionCue();
 195     }
 196
 197     if (prefs->getBool("/tools/shapes/gradientdrag")) {
 198         ec->enableGrDrag();
 199     }
 200
 201     ac->_message_context = new Inkscape::MessageContext(ec->desktop->messageStack());
 202 }
 203
 204 static gint sp_arc_context_item_handler(SPEventContext *event_context, SPItem *item, GdkEvent *event)
 205 {
 206     SPDesktop *desktop = event_context->desktop;
 207     gint ret = FALSE;
 208
 209     switch (event->type) {
 210         case GDK_BUTTON_PRESS:
 211             if (event->button.button == 1 && !event_context->space_panning) {
 212                 Inkscape::setup_for_drag_start(desktop, event_context, event);
 213                 ret = TRUE;
 214             }
 215             break;
 216             // motion and release are always on root (why?)
 217         default:
 218             break;
 219     }
 220
 221     if (((SPEventContextClass *) parent_class)->item_handler) {
 222         ret = ((SPEventContextClass *) parent_class)->item_handler(event_context, item, event);
 223     }
 224
 225     return ret;
 226 }
 227
 228 static gint sp_arc_context_root_handler(SPEventContext *event_context, GdkEvent *event)
 229 {
 230     static bool dragging;
 231
 232     SPDesktop *desktop = event_context->desktop;
 233     Inkscape::Selection *selection = sp_desktop_selection(desktop);
 234     SPArcContext *ac = SP_ARC_CONTEXT(event_context);
 235     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 236
 237     event_context->tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
 238
 239     gint ret = FALSE;
 240
 241     switch (event->type) {
 242         case GDK_BUTTON_PRESS:
 243             if (event->button.button == 1 && !event_context->space_panning) {
 244
 245                 dragging = true;
 246                 ac->center = Inkscape::setup_for_drag_start(desktop, event_context, event);
 247
 248                 /* Snap center */
 249                 SnapManager &m = desktop->namedview->snap_manager;
 250                 m.setup(desktop);
 251                 m.freeSnapReturnByRef(ac->center, Inkscape::SNAPSOURCE_NODE_HANDLE);
 252
 253                 sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 254                                     GDK_KEY_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
 255                                     GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK,
 256                                     NULL, event->button.time);
 257                 ret = TRUE;
 258                 m.unSetup();
 259             }
 260             break;
 261         case GDK_MOTION_NOTIFY:
 262             if (dragging && (event->motion.state & GDK_BUTTON1_MASK) && !event_context->space_panning) {
 263
 264                 if ( event_context->within_tolerance
 265                      && ( abs( (gint) event->motion.x - event_context->xp ) < event_context->tolerance )
 266                      && ( abs( (gint) event->motion.y - event_context->yp ) < event_context->tolerance ) ) {
 267                     break; // do not drag if we're within tolerance from origin
 268                 }
 269                 // Once the user has moved farther than tolerance from the original location
 270                 // (indicating they intend to draw, not click), then always process the
 271                 // motion notify coordinates as given (no snapping back to origin)
 272                 event_context->within_tolerance = false;
 273
 274                 Geom::Point const motion_w(event->motion.x, event->motion.y);
 275                 Geom::Point motion_dt(desktop->w2d(motion_w));
 276
 277                 sp_arc_drag(ac, motion_dt, event->motion.state);
 278
 279                 gobble_motion_events(GDK_BUTTON1_MASK);
 280
 281                 ret = TRUE;
 282             } else if (!sp_event_context_knot_mouseover(ac)){
 283                 SnapManager &m = desktop->namedview->snap_manager;
 284                 m.setup(desktop);
 285
 286                 Geom::Point const motion_w(event->motion.x, event->motion.y);
 287                 Geom::Point motion_dt(desktop->w2d(motion_w));
 288                 m.preSnap(Inkscape::SnapCandidatePoint(motion_dt, Inkscape::SNAPSOURCE_NODE_HANDLE));
 289                 m.unSetup();
 290             }
 291             break;
 292         case GDK_BUTTON_RELEASE:
 293             event_context->xp = event_context->yp = 0;
 294             if (event->button.button == 1 && !event_context->space_panning) {
 295                 dragging = false;
 296                 sp_event_context_discard_delayed_snap_event(event_context);
 297                 if (!event_context->within_tolerance) {
 298                     // we've been dragging, finish the arc
 299                        sp_arc_finish(ac);
 300                 } else if (event_context->item_to_select) {
 301                     // no dragging, select clicked item if any
 302                     if (event->button.state & GDK_SHIFT_MASK) {
 303                         selection->toggle(event_context->item_to_select);
 304                     } else {
 305                         selection->set(event_context->item_to_select);
 306                     }
 307                 } else {
 308                     // click in an empty space
 309                     selection->clear();
 310                 }
 311                 event_context->xp = 0;
 312                 event_context->yp = 0;
 313                 event_context->item_to_select = NULL;
 314                 ret = TRUE;
 315             }
 316             sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 317             break;
 318         case GDK_KEY_PRESS:
 319             switch (get_group0_keyval (&event->key)) {
 320                 case GDK_Alt_L:
 321                 case GDK_Alt_R:
 322                 case GDK_Control_L:
 323                 case GDK_Control_R:
 324                 case GDK_Shift_L:
 325                 case GDK_Shift_R:
 326                 case GDK_Meta_L:  // Meta is when you press Shift+Alt (at least on my machine)
 327                 case GDK_Meta_R:
 328                     if (!dragging) {
 329                         sp_event_show_modifier_tip(event_context->defaultMessageContext(), event,
 330                                                    _("<b>Ctrl</b>: make circle or integer-ratio ellipse, snap arc/segment angle"),
 331                                                    _("<b>Shift</b>: draw around the starting point"),
 332                                                    NULL);
 333                     }
 334                     break;
 335                 case GDK_Up:
 336                 case GDK_Down:
 337                 case GDK_KP_Up:
 338                 case GDK_KP_Down:
 339                     // prevent the zoom field from activation
 340                     if (!MOD__CTRL_ONLY)
 341                         ret = TRUE;
 342                     break;
 343                 case GDK_x:
 344                 case GDK_X:
 345                     if (MOD__ALT_ONLY) {
 346                         desktop->setToolboxFocusTo ("altx-arc");
 347                         ret = TRUE;
 348                     }
 349                     break;
 350                 case GDK_Escape:
 351                     if (dragging) {
 352                         dragging = false;
 353                         sp_event_context_discard_delayed_snap_event(event_context);
 354                         // if drawing, cancel, otherwise pass it up for deselecting
 355                         sp_arc_cancel(ac);
 356                         ret = TRUE;
 357                     }
 358                     break;
 359                 case GDK_space:
 360                     if (dragging) {
 361                         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate),
 362                                               event->button.time);
 363                         dragging = false;
 364                         sp_event_context_discard_delayed_snap_event(event_context);
 365                         if (!event_context->within_tolerance) {
 366                             // we've been dragging, finish the arc
 367                             sp_arc_finish(ac);
 368                         }
 369                         // do not return true, so that space would work switching to selector
 370                     }
 371                     break;
 372
 373                 default:
 374                     break;
 375             }
 376             break;
 377         case GDK_KEY_RELEASE:
 378             switch (event->key.keyval) {
 379                 case GDK_Alt_L:
 380                 case GDK_Alt_R:
 381                 case GDK_Control_L:
 382                 case GDK_Control_R:
 383                 case GDK_Shift_L:
 384                 case GDK_Shift_R:
 385                 case GDK_Meta_L:  // Meta is when you press Shift+Alt
 386                 case GDK_Meta_R:
 387                     event_context->defaultMessageContext()->clear();
 388                     break;
 389                 default:
 390                     break;
 391             }
 392             break;
 393         default:
 394             break;
 395     }
 396
 397     if (!ret) {
 398         if (((SPEventContextClass *) parent_class)->root_handler) {
 399             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
 400         }
 401     }
 402
 403     return ret;
 404 }
 405
 406 static void sp_arc_drag(SPArcContext *ac, Geom::Point pt, guint state)
 407 {
 408     SPDesktop *desktop = SP_EVENT_CONTEXT(ac)->desktop;
 409
 410     if (!ac->item) {
 411
 412         if (Inkscape::have_viable_layer(desktop, ac->_message_context) == false) {
 413             return;
 414         }
 415
 416         // Create object
 417         Inkscape::XML::Document *xml_doc = desktop->doc()->getReprDoc();
 418         Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");
 419         repr->setAttribute("sodipodi:type", "arc");
 420
 421         // Set style
 422         sp_desktop_apply_style_tool(desktop, repr, "/tools/shapes/arc", false);
 423
 424         ac->item = SP_ITEM(desktop->currentLayer()->appendChildRepr(repr));
 425         Inkscape::GC::release(repr);
 426         ac->item->transform = SP_ITEM(desktop->currentLayer())->i2doc_affine().inverse();
 427         ac->item->updateRepr();
 428
 429         sp_canvas_force_full_redraw_after_interruptions(desktop->canvas, 5);
 430     }
 431
 432     bool ctrl_save = false;
 433     if ((state & GDK_MOD1_MASK) && (state & GDK_CONTROL_MASK) && !(state & GDK_SHIFT_MASK)) {
 434         // if Alt is pressed without Shift in addition to Control, temporarily drop the CONTROL mask
 435         // so that the ellipse is not constrained to integer ratios
 436         ctrl_save = true;
 437         state = state ^ GDK_CONTROL_MASK;
 438     }
 439     Geom::Rect r = Inkscape::snap_rectangular_box(desktop, ac->item, pt, ac->center, state);
 440     if (ctrl_save) {
 441         state = state ^ GDK_CONTROL_MASK;
 442     }
 443
 444     Geom::Point dir = r.dimensions() / 2;
 445     if (state & GDK_MOD1_MASK) {
 446         /* With Alt let the ellipse pass through the mouse pointer */
 447         Geom::Point c = r.midpoint();
 448         if (!ctrl_save) {
 449             if (fabs(dir[Geom::X]) > 1E-6 && fabs(dir[Geom::Y]) > 1E-6) {
 450                 Geom::Matrix const i2d ((ac->item)->i2d_affine ());
 451                 Geom::Point new_dir = pt * i2d - c;
 452                 new_dir[Geom::X] *= dir[Geom::Y] / dir[Geom::X];
 453                 double lambda = new_dir.length() / dir[Geom::Y];
 454                 r = Geom::Rect (c - lambda*dir, c + lambda*dir);
 455             }
 456         } else {
 457             /* with Alt+Ctrl (without Shift) we generate a perfect circle
 458                with diameter click point <--> mouse pointer */
 459                 double l = dir.length();
 460                 Geom::Point d (l, l);
 461                 r = Geom::Rect (c - d, c + d);
 462         }
 463     }
 464
 465     sp_arc_position_set(SP_ARC(ac->item),
 466                         r.midpoint()[Geom::X], r.midpoint()[Geom::Y],
 467                         r.dimensions()[Geom::X] / 2, r.dimensions()[Geom::Y] / 2);
 468
 469     double rdimx = r.dimensions()[Geom::X];
 470     double rdimy = r.dimensions()[Geom::Y];
 471     GString *xs = SP_PX_TO_METRIC_STRING(rdimx, desktop->namedview->getDefaultMetric());
 472     GString *ys = SP_PX_TO_METRIC_STRING(rdimy, desktop->namedview->getDefaultMetric());
 473     if (state & GDK_CONTROL_MASK) {
 474         int ratio_x, ratio_y;
 475         if (fabs (rdimx) > fabs (rdimy)) {
 476             ratio_x = (int) rint (rdimx / rdimy);
 477             ratio_y = 1;
 478         } else {
 479             ratio_x = 1;
 480             ratio_y = (int) rint (rdimy / rdimx);
 481         }
 482         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);
 483     } else {
 484         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);
 485     }
 486     g_string_free(xs, FALSE);
 487     g_string_free(ys, FALSE);
 488 }
 489
 490 static void sp_arc_finish(SPArcContext *ac)
 491 {
 492     ac->_message_context->clear();
 493
 494     if (ac->item != NULL) {
 495
 496         SPGenericEllipse *ge = SP_GENERICELLIPSE(SP_ARC(ac->item));
 497         if (ge->rx.computed == 0 || ge->ry.computed == 0) {
 498             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
 499             return;
 500         }
 501
 502         SPDesktop *desktop = SP_EVENT_CONTEXT(ac)->desktop;
 503
 504         SP_OBJECT(ac->item)->updateRepr();
 505
 506         sp_canvas_end_forced_full_redraws(desktop->canvas);
 507
 508         sp_desktop_selection(desktop)->set(ac->item);
 509                 DocumentUndo::done(sp_desktop_document(desktop), SP_VERB_CONTEXT_ARC,
 510                          _("Create ellipse"));
 511
 512         ac->item = NULL;
 513     }
 514 }
 515
 516 static void sp_arc_cancel(SPArcContext *ac)
 517 {
 518     SPDesktop *desktop = SP_EVENT_CONTEXT(ac)->desktop;
 519
 520     sp_desktop_selection(desktop)->clear();
 521     sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), 0);
 522
 523     if (ac->item != NULL) {
 524         SP_OBJECT(ac->item)->deleteObject();
 525         ac->item = NULL;
 526     }
 527
 528     ac->within_tolerance = false;
 529     ac->xp = 0;
 530     ac->yp = 0;
 531     ac->item_to_select = NULL;
 532
 533     sp_canvas_end_forced_full_redraws(desktop->canvas);
 534
 535     DocumentUndo::cancel(sp_desktop_document(desktop));
 536 }
 537
 538
 539 /*
 540   Local Variables:
 541   mode:c++
 542   c-file-style:"stroustrup"
 543   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 544   indent-tabs-mode:nil
 545   fill-column:99
 546   End:
 547 */
 548 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :