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
  45 #include "arc-context.h"
  46
  47 static void sp_arc_context_class_init(SPArcContextClass *klass);
  48 static void sp_arc_context_init(SPArcContext *arc_context);
  49 static void sp_arc_context_dispose(GObject *object);
  50
  51 static void sp_arc_context_setup(SPEventContext *ec);
  52 static gint sp_arc_context_root_handler(SPEventContext *event_context, GdkEvent *event);
  53 static gint sp_arc_context_item_handler(SPEventContext *event_context, SPItem *item, GdkEvent *event);
  54
  55 static void sp_arc_drag(SPArcContext *ec, Geom::Point pt, guint state);
  56 static void sp_arc_finish(SPArcContext *ec);
  57
  58 static SPEventContextClass *parent_class;
  59
  60 GtkType sp_arc_context_get_type()
  61 {
  62     static GType type = 0;
  63     if (!type) {
  64         GTypeInfo info = {
  65             sizeof(SPArcContextClass),
  66             NULL, NULL,
  67             (GClassInitFunc) sp_arc_context_class_init,
  68             NULL, NULL,
  69             sizeof(SPArcContext),
  70             4,
  71             (GInstanceInitFunc) sp_arc_context_init,
  72             NULL,   /* value_table */
  73         };
  74         type = g_type_register_static(SP_TYPE_EVENT_CONTEXT, "SPArcContext", &info, (GTypeFlags) 0);
  75     }
  76     return type;
  77 }
  78
  79 static void sp_arc_context_class_init(SPArcContextClass *klass)
  80 {
  81
  82     GObjectClass *object_class = (GObjectClass *) klass;
  83     SPEventContextClass *event_context_class = (SPEventContextClass *) klass;
  84
  85     parent_class = (SPEventContextClass*) g_type_class_peek_parent(klass);
  86
  87     object_class->dispose = sp_arc_context_dispose;
  88
  89     event_context_class->setup = sp_arc_context_setup;
  90     event_context_class->root_handler = sp_arc_context_root_handler;
  91     event_context_class->item_handler = sp_arc_context_item_handler;
  92 }
  93
  94 static void sp_arc_context_init(SPArcContext *arc_context)
  95 {
  96     SPEventContext *event_context = SP_EVENT_CONTEXT(arc_context);
  97
  98     event_context->cursor_shape = cursor_ellipse_xpm;
  99     event_context->hot_x = 4;
 100     event_context->hot_y = 4;
 101     event_context->xp = 0;
 102     event_context->yp = 0;
 103     event_context->tolerance = 0;
 104     event_context->within_tolerance = false;
 105     event_context->item_to_select = NULL;
 106
 107     arc_context->item = NULL;
 108
 109     new (&arc_context->sel_changed_connection) sigc::connection();
 110 }
 111
 112 static void sp_arc_context_dispose(GObject *object)
 113 {
 114     SPEventContext *ec = SP_EVENT_CONTEXT(object);
 115     SPArcContext *ac = SP_ARC_CONTEXT(object);
 116
 117     ec->enableGrDrag(false);
 118
 119     ac->sel_changed_connection.disconnect();
 120     ac->sel_changed_connection.~connection();
 121
 122     delete ec->shape_editor;
 123     ec->shape_editor = NULL;
 124
 125     /* fixme: This is necessary because we do not grab */
 126     if (ac->item) {
 127         sp_arc_finish(ac);
 128     }
 129
 130     delete ac->_message_context;
 131
 132     G_OBJECT_CLASS(parent_class)->dispose(object);
 133 }
 134
 135 /**
 136 \brief  Callback that processes the "changed" signal on the selection;
 137 destroys old and creates new knotholder.
 138 */
 139 void sp_arc_context_selection_changed(Inkscape::Selection * selection, gpointer data)
 140 {
 141     SPArcContext *ac = SP_ARC_CONTEXT(data);
 142     SPEventContext *ec = SP_EVENT_CONTEXT(ac);
 143
 144     ec->shape_editor->unset_item(SH_KNOTHOLDER);
 145     SPItem *item = selection->singleItem();
 146     ec->shape_editor->set_item(item, SH_KNOTHOLDER);
 147 }
 148
 149 static void sp_arc_context_setup(SPEventContext *ec)
 150 {
 151     SPArcContext *ac = SP_ARC_CONTEXT(ec);
 152     Inkscape::Selection *selection = sp_desktop_selection(ec->desktop);
 153
 154     if (((SPEventContextClass *) parent_class)->setup) {
 155         ((SPEventContextClass *) parent_class)->setup(ec);
 156     }
 157
 158     ec->shape_editor = new ShapeEditor(ec->desktop);
 159
 160     SPItem *item = sp_desktop_selection(ec->desktop)->singleItem();
 161     if (item) {
 162         ec->shape_editor->set_item(item, SH_KNOTHOLDER);
 163     }
 164
 165     ac->sel_changed_connection.disconnect();
 166     ac->sel_changed_connection = selection->connectChanged(
 167         sigc::bind(sigc::ptr_fun(&sp_arc_context_selection_changed), (gpointer) ac)
 168         );
 169
 170     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 171     if (prefs->getBool("/tools/shapes/selcue")) {
 172         ec->enableSelectionCue();
 173     }
 174
 175     if (prefs->getBool("/tools/shapes/gradientdrag")) {
 176         ec->enableGrDrag();
 177     }
 178
 179     ac->_message_context = new Inkscape::MessageContext(ec->desktop->messageStack());
 180 }
 181
 182 static gint sp_arc_context_item_handler(SPEventContext *event_context, SPItem *item, GdkEvent *event)
 183 {
 184     SPDesktop *desktop = event_context->desktop;
 185     gint ret = FALSE;
 186
 187     switch (event->type) {
 188         case GDK_BUTTON_PRESS:
 189             if (event->button.button == 1 && !event_context->space_panning) {
 190                 Inkscape::setup_for_drag_start(desktop, event_context, event);
 191                 ret = TRUE;
 192             }
 193             break;
 194             // motion and release are always on root (why?)
 195         default:
 196             break;
 197     }
 198
 199     if (((SPEventContextClass *) parent_class)->item_handler) {
 200         ret = ((SPEventContextClass *) parent_class)->item_handler(event_context, item, event);
 201     }
 202
 203     return ret;
 204 }
 205
 206 static gint sp_arc_context_root_handler(SPEventContext *event_context, GdkEvent *event)
 207 {
 208     static bool dragging;
 209
 210     SPDesktop *desktop = event_context->desktop;
 211     Inkscape::Selection *selection = sp_desktop_selection(desktop);
 212     SPArcContext *ac = SP_ARC_CONTEXT(event_context);
 213     Inkscape::Preferences *prefs = Inkscape::Preferences::get();
 214
 215     event_context->tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
 216
 217     gint ret = FALSE;
 218
 219     switch (event->type) {
 220         case GDK_BUTTON_PRESS:
 221             if (event->button.button == 1 && !event_context->space_panning) {
 222
 223                 dragging = true;
 224                 ac->center = Inkscape::setup_for_drag_start(desktop, event_context, event);
 225
 226                 /* Snap center */
 227                 SnapManager &m = desktop->namedview->snap_manager;
 228                 m.setup(desktop);
 229                 Geom::Point pt2g = to_2geom(ac->center);
 230                 m.freeSnapReturnByRef(Inkscape::SnapPreferences::SNAPPOINT_NODE, pt2g);
 231                 ac->center = from_2geom(pt2g);
 232
 233                 sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 234                                     GDK_KEY_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
 235                                     GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK,
 236                                     NULL, event->button.time);
 237                 ret = TRUE;
 238             }
 239             break;
 240         case GDK_MOTION_NOTIFY:
 241             if (dragging && (event->motion.state & GDK_BUTTON1_MASK) && !event_context->space_panning) {
 242
 243                 if ( event_context->within_tolerance
 244                      && ( abs( (gint) event->motion.x - event_context->xp ) < event_context->tolerance )
 245                      && ( abs( (gint) event->motion.y - event_context->yp ) < event_context->tolerance ) ) {
 246                     break; // do not drag if we're within tolerance from origin
 247                 }
 248                 // Once the user has moved farther than tolerance from the original location
 249                 // (indicating they intend to draw, not click), then always process the
 250                 // motion notify coordinates as given (no snapping back to origin)
 251                 event_context->within_tolerance = false;
 252
 253                 Geom::Point const motion_w(event->motion.x, event->motion.y);
 254                 Geom::Point motion_dt(desktop->w2d(motion_w));
 255
 256                 sp_arc_drag(ac, motion_dt, event->motion.state);
 257
 258                 gobble_motion_events(GDK_BUTTON1_MASK);
 259
 260                 ret = TRUE;
 261             }
 262             break;
 263         case GDK_BUTTON_RELEASE:
 264             event_context->xp = event_context->yp = 0;
 265             if (event->button.button == 1 && !event_context->space_panning) {
 266                 dragging = false;
 267                 if (!event_context->within_tolerance) {
 268                     // we've been dragging, finish the arc
 269                     sp_arc_finish(ac);
 270                 } else if (event_context->item_to_select) {
 271                     // no dragging, select clicked item if any
 272                     if (event->button.state & GDK_SHIFT_MASK) {
 273                         selection->toggle(event_context->item_to_select);
 274                     } else {
 275                         selection->set(event_context->item_to_select);
 276                     }
 277                 } else {
 278                     // click in an empty space
 279                     selection->clear();
 280                 }
 281                 event_context->xp = 0;
 282                 event_context->yp = 0;
 283                 event_context->item_to_select = NULL;
 284                 ret = TRUE;
 285             }
 286             sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 287             break;
 288         case GDK_KEY_PRESS:
 289             switch (get_group0_keyval (&event->key)) {
 290                 case GDK_Alt_L:
 291                 case GDK_Alt_R:
 292                 case GDK_Control_L:
 293                 case GDK_Control_R:
 294                 case GDK_Shift_L:
 295                 case GDK_Shift_R:
 296                 case GDK_Meta_L:  // Meta is when you press Shift+Alt (at least on my machine)
 297                 case GDK_Meta_R:
 298                     if (!dragging) {
 299                         sp_event_show_modifier_tip(event_context->defaultMessageContext(), event,
 300                                                    _("<b>Ctrl</b>: make circle or integer-ratio ellipse, snap arc/segment angle"),
 301                                                    _("<b>Shift</b>: draw around the starting point"),
 302                                                    NULL);
 303                     }
 304                     break;
 305                 case GDK_Up:
 306                 case GDK_Down:
 307                 case GDK_KP_Up:
 308                 case GDK_KP_Down:
 309                     // prevent the zoom field from activation
 310                     if (!MOD__CTRL_ONLY)
 311                         ret = TRUE;
 312                     break;
 313                 case GDK_x:
 314                 case GDK_X:
 315                     if (MOD__ALT_ONLY) {
 316                         desktop->setToolboxFocusTo ("altx-arc");
 317                         ret = TRUE;
 318                     }
 319                     break;
 320                 case GDK_Escape:
 321                     sp_desktop_selection(desktop)->clear();
 322                     //TODO: make dragging escapable by Esc
 323                     break;
 324
 325                 case GDK_space:
 326                     if (dragging) {
 327                         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate),
 328                                               event->button.time);
 329                         dragging = false;
 330                         if (!event_context->within_tolerance) {
 331                             // we've been dragging, finish the rect
 332                             sp_arc_finish(ac);
 333                         }
 334                         // do not return true, so that space would work switching to selector
 335                     }
 336                     break;
 337
 338                 default:
 339                     break;
 340             }
 341             break;
 342         case GDK_KEY_RELEASE:
 343             switch (event->key.keyval) {
 344                 case GDK_Alt_L:
 345                 case GDK_Alt_R:
 346                 case GDK_Control_L:
 347                 case GDK_Control_R:
 348                 case GDK_Shift_L:
 349                 case GDK_Shift_R:
 350                 case GDK_Meta_L:  // Meta is when you press Shift+Alt
 351                 case GDK_Meta_R:
 352                     event_context->defaultMessageContext()->clear();
 353                     break;
 354                 default:
 355                     break;
 356             }
 357             break;
 358         default:
 359             break;
 360     }
 361
 362     if (!ret) {
 363         if (((SPEventContextClass *) parent_class)->root_handler) {
 364             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
 365         }
 366     }
 367
 368     return ret;
 369 }
 370
 371 static void sp_arc_drag(SPArcContext *ac, Geom::Point pt, guint state)
 372 {
 373     SPDesktop *desktop = SP_EVENT_CONTEXT(ac)->desktop;
 374
 375     if (!ac->item) {
 376
 377         if (Inkscape::have_viable_layer(desktop, ac->_message_context) == false) {
 378             return;
 379         }
 380
 381         /* Create object */
 382         Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
 383         Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");
 384         repr->setAttribute("sodipodi:type", "arc");
 385
 386         /* Set style */
 387         sp_desktop_apply_style_tool(desktop, repr, "/tools/shapes/arc", false);
 388
 389         ac->item = SP_ITEM(desktop->currentLayer()->appendChildRepr(repr));
 390         Inkscape::GC::release(repr);
 391         ac->item->transform = sp_item_i2doc_affine(SP_ITEM(desktop->currentLayer())).inverse();
 392         ac->item->updateRepr();
 393
 394         sp_canvas_force_full_redraw_after_interruptions(desktop->canvas, 5);
 395     }
 396
 397     bool ctrl_save = false;
 398     if ((state & GDK_MOD1_MASK) && (state & GDK_CONTROL_MASK) && !(state & GDK_SHIFT_MASK)) {
 399         // if Alt is pressed without Shift in addition to Control, temporarily drop the CONTROL mask
 400         // so that the ellipse is not constrained to integer ratios
 401         ctrl_save = true;
 402         state = state ^ GDK_CONTROL_MASK;
 403     }
 404     Geom::Rect r = Inkscape::snap_rectangular_box(desktop, ac->item, pt, ac->center, state);
 405     if (ctrl_save) {
 406         state = state ^ GDK_CONTROL_MASK;
 407     }
 408
 409     Geom::Point dir = r.dimensions() / 2;
 410     if (state & GDK_MOD1_MASK) {
 411         /* With Alt let the ellipse pass through the mouse pointer */
 412         Geom::Point c = r.midpoint();
 413         if (!ctrl_save) {
 414             if (fabs(dir[Geom::X]) > 1E-6 && fabs(dir[Geom::Y]) > 1E-6) {
 415                 Geom::Matrix const i2d (sp_item_i2d_affine (ac->item));
 416                 Geom::Point new_dir = pt * i2d - c;
 417                 new_dir[Geom::X] *= dir[Geom::Y] / dir[Geom::X];
 418                 double lambda = new_dir.length() / dir[Geom::Y];
 419                 r = Geom::Rect (c - lambda*dir, c + lambda*dir);
 420             }
 421         } else {
 422             /* with Alt+Ctrl (without Shift) we generate a perfect circle
 423                with diameter click point <--> mouse pointer */
 424                 double l = dir.length();
 425                 Geom::Point d (l, l);
 426                 r = Geom::Rect (c - d, c + d);
 427         }
 428     }
 429
 430     sp_arc_position_set(SP_ARC(ac->item),
 431                         r.midpoint()[Geom::X], r.midpoint()[Geom::Y],
 432                         r.dimensions()[Geom::X] / 2, r.dimensions()[Geom::Y] / 2);
 433
 434     double rdimx = r.dimensions()[Geom::X];
 435     double rdimy = r.dimensions()[Geom::Y];
 436     GString *xs = SP_PX_TO_METRIC_STRING(rdimx, desktop->namedview->getDefaultMetric());
 437     GString *ys = SP_PX_TO_METRIC_STRING(rdimy, desktop->namedview->getDefaultMetric());
 438     if (state & GDK_CONTROL_MASK) {
 439         int ratio_x, ratio_y;
 440         if (fabs (rdimx) > fabs (rdimy)) {
 441             ratio_x = (int) rint (rdimx / rdimy);
 442             ratio_y = 1;
 443         } else {
 444             ratio_x = 1;
 445             ratio_y = (int) rint (rdimy / rdimx);
 446         }
 447         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);
 448     } else {
 449         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);
 450     }
 451     g_string_free(xs, FALSE);
 452     g_string_free(ys, FALSE);
 453 }
 454
 455 static void sp_arc_finish(SPArcContext *ac)
 456 {
 457     ac->_message_context->clear();
 458
 459     if (ac->item != NULL) {
 460         SPDesktop *desktop = SP_EVENT_CONTEXT(ac)->desktop;
 461
 462         SP_OBJECT(ac->item)->updateRepr();
 463
 464         sp_canvas_end_forced_full_redraws(desktop->canvas);
 465
 466         sp_desktop_selection(desktop)->set(ac->item);
 467         sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_ARC,
 468                          _("Create ellipse"));
 469
 470         ac->item = NULL;
 471     }
 472 }
 473
 474
 475 /*
 476   Local Variables:
 477   mode:c++
 478   c-file-style:"stroustrup"
 479   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 480   indent-tabs-mode:nil
 481   fill-column:99
 482   End:
 483 */
 484 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :