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                 sp_canvas_set_snap_delay_active(desktop->canvas, true);
 225                 ac->center = Inkscape::setup_for_drag_start(desktop, event_context, event);
 226
 227                 /* Snap center */
 228                 SnapManager &m = desktop->namedview->snap_manager;
 229                 m.setup(desktop);
 230                 Geom::Point pt2g = to_2geom(ac->center);
 231                 m.freeSnapReturnByRef(Inkscape::SnapPreferences::SNAPPOINT_NODE, pt2g);
 232                 ac->center = from_2geom(pt2g);
 233
 234                 sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 235                                     GDK_KEY_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
 236                                     GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK | GDK_BUTTON_PRESS_MASK,
 237                                     NULL, event->button.time);
 238                 ret = TRUE;
 239             }
 240             break;
 241         case GDK_MOTION_NOTIFY:
 242             if (dragging && (event->motion.state & GDK_BUTTON1_MASK) && !event_context->space_panning) {
 243
 244                 if ( event_context->within_tolerance
 245                      && ( abs( (gint) event->motion.x - event_context->xp ) < event_context->tolerance )
 246                      && ( abs( (gint) event->motion.y - event_context->yp ) < event_context->tolerance ) ) {
 247                     break; // do not drag if we're within tolerance from origin
 248                 }
 249                 // Once the user has moved farther than tolerance from the original location
 250                 // (indicating they intend to draw, not click), then always process the
 251                 // motion notify coordinates as given (no snapping back to origin)
 252                 event_context->within_tolerance = false;
 253
 254                 Geom::Point const motion_w(event->motion.x, event->motion.y);
 255                 Geom::Point motion_dt(desktop->w2d(motion_w));
 256
 257                 sp_arc_drag(ac, motion_dt, event->motion.state);
 258
 259                 gobble_motion_events(GDK_BUTTON1_MASK);
 260
 261                 ret = TRUE;
 262             }
 263             break;
 264         case GDK_BUTTON_RELEASE:
 265             event_context->xp = event_context->yp = 0;
 266             if (event->button.button == 1 && !event_context->space_panning) {
 267                 dragging = false;
 268                 sp_canvas_set_snap_delay_active(desktop->canvas, false);
 269                 if (!event_context->within_tolerance) {
 270                     // we've been dragging, finish the arc
 271                     sp_arc_finish(ac);
 272                 } else if (event_context->item_to_select) {
 273                     // no dragging, select clicked item if any
 274                     if (event->button.state & GDK_SHIFT_MASK) {
 275                         selection->toggle(event_context->item_to_select);
 276                     } else {
 277                         selection->set(event_context->item_to_select);
 278                     }
 279                 } else {
 280                     // click in an empty space
 281                     selection->clear();
 282                 }
 283                 event_context->xp = 0;
 284                 event_context->yp = 0;
 285                 event_context->item_to_select = NULL;
 286                 ret = TRUE;
 287             }
 288             sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate), event->button.time);
 289             break;
 290         case GDK_KEY_PRESS:
 291             switch (get_group0_keyval (&event->key)) {
 292                 case GDK_Alt_L:
 293                 case GDK_Alt_R:
 294                 case GDK_Control_L:
 295                 case GDK_Control_R:
 296                 case GDK_Shift_L:
 297                 case GDK_Shift_R:
 298                 case GDK_Meta_L:  // Meta is when you press Shift+Alt (at least on my machine)
 299                 case GDK_Meta_R:
 300                     if (!dragging) {
 301                         sp_event_show_modifier_tip(event_context->defaultMessageContext(), event,
 302                                                    _("<b>Ctrl</b>: make circle or integer-ratio ellipse, snap arc/segment angle"),
 303                                                    _("<b>Shift</b>: draw around the starting point"),
 304                                                    NULL);
 305                     }
 306                     break;
 307                 case GDK_Up:
 308                 case GDK_Down:
 309                 case GDK_KP_Up:
 310                 case GDK_KP_Down:
 311                     // prevent the zoom field from activation
 312                     if (!MOD__CTRL_ONLY)
 313                         ret = TRUE;
 314                     break;
 315                 case GDK_x:
 316                 case GDK_X:
 317                     if (MOD__ALT_ONLY) {
 318                         desktop->setToolboxFocusTo ("altx-arc");
 319                         ret = TRUE;
 320                     }
 321                     break;
 322                 case GDK_Escape:
 323                     sp_desktop_selection(desktop)->clear();
 324                     //TODO: make dragging escapable by Esc
 325                     break;
 326
 327                 case GDK_space:
 328                     if (dragging) {
 329                         sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate),
 330                                               event->button.time);
 331                         dragging = false;
 332                         sp_canvas_set_snap_delay_active(desktop->canvas, false);
 333                         if (!event_context->within_tolerance) {
 334                             // we've been dragging, finish the rect
 335                             sp_arc_finish(ac);
 336                         }
 337                         // do not return true, so that space would work switching to selector
 338                     }
 339                     break;
 340
 341                 default:
 342                     break;
 343             }
 344             break;
 345         case GDK_KEY_RELEASE:
 346             switch (event->key.keyval) {
 347                 case GDK_Alt_L:
 348                 case GDK_Alt_R:
 349                 case GDK_Control_L:
 350                 case GDK_Control_R:
 351                 case GDK_Shift_L:
 352                 case GDK_Shift_R:
 353                 case GDK_Meta_L:  // Meta is when you press Shift+Alt
 354                 case GDK_Meta_R:
 355                     event_context->defaultMessageContext()->clear();
 356                     break;
 357                 default:
 358                     break;
 359             }
 360             break;
 361         default:
 362             break;
 363     }
 364
 365     if (!ret) {
 366         if (((SPEventContextClass *) parent_class)->root_handler) {
 367             ret = ((SPEventContextClass *) parent_class)->root_handler(event_context, event);
 368         }
 369     }
 370
 371     return ret;
 372 }
 373
 374 static void sp_arc_drag(SPArcContext *ac, Geom::Point pt, guint state)
 375 {
 376     SPDesktop *desktop = SP_EVENT_CONTEXT(ac)->desktop;
 377
 378     if (!ac->item) {
 379
 380         if (Inkscape::have_viable_layer(desktop, ac->_message_context) == false) {
 381             return;
 382         }
 383
 384         /* Create object */
 385         Inkscape::XML::Document *xml_doc = sp_document_repr_doc(desktop->doc());
 386         Inkscape::XML::Node *repr = xml_doc->createElement("svg:path");
 387         repr->setAttribute("sodipodi:type", "arc");
 388
 389         /* Set style */
 390         sp_desktop_apply_style_tool(desktop, repr, "/tools/shapes/arc", false);
 391
 392         ac->item = SP_ITEM(desktop->currentLayer()->appendChildRepr(repr));
 393         Inkscape::GC::release(repr);
 394         ac->item->transform = sp_item_i2doc_affine(SP_ITEM(desktop->currentLayer())).inverse();
 395         ac->item->updateRepr();
 396
 397         sp_canvas_force_full_redraw_after_interruptions(desktop->canvas, 5);
 398     }
 399
 400     bool ctrl_save = false;
 401     if ((state & GDK_MOD1_MASK) && (state & GDK_CONTROL_MASK) && !(state & GDK_SHIFT_MASK)) {
 402         // if Alt is pressed without Shift in addition to Control, temporarily drop the CONTROL mask
 403         // so that the ellipse is not constrained to integer ratios
 404         ctrl_save = true;
 405         state = state ^ GDK_CONTROL_MASK;
 406     }
 407     Geom::Rect r = Inkscape::snap_rectangular_box(desktop, ac->item, pt, ac->center, state);
 408     if (ctrl_save) {
 409         state = state ^ GDK_CONTROL_MASK;
 410     }
 411
 412     Geom::Point dir = r.dimensions() / 2;
 413     if (state & GDK_MOD1_MASK) {
 414         /* With Alt let the ellipse pass through the mouse pointer */
 415         Geom::Point c = r.midpoint();
 416         if (!ctrl_save) {
 417             if (fabs(dir[Geom::X]) > 1E-6 && fabs(dir[Geom::Y]) > 1E-6) {
 418                 Geom::Matrix const i2d (sp_item_i2d_affine (ac->item));
 419                 Geom::Point new_dir = pt * i2d - c;
 420                 new_dir[Geom::X] *= dir[Geom::Y] / dir[Geom::X];
 421                 double lambda = new_dir.length() / dir[Geom::Y];
 422                 r = Geom::Rect (c - lambda*dir, c + lambda*dir);
 423             }
 424         } else {
 425             /* with Alt+Ctrl (without Shift) we generate a perfect circle
 426                with diameter click point <--> mouse pointer */
 427                 double l = dir.length();
 428                 Geom::Point d (l, l);
 429                 r = Geom::Rect (c - d, c + d);
 430         }
 431     }
 432
 433     sp_arc_position_set(SP_ARC(ac->item),
 434                         r.midpoint()[Geom::X], r.midpoint()[Geom::Y],
 435                         r.dimensions()[Geom::X] / 2, r.dimensions()[Geom::Y] / 2);
 436
 437     double rdimx = r.dimensions()[Geom::X];
 438     double rdimy = r.dimensions()[Geom::Y];
 439     GString *xs = SP_PX_TO_METRIC_STRING(rdimx, desktop->namedview->getDefaultMetric());
 440     GString *ys = SP_PX_TO_METRIC_STRING(rdimy, desktop->namedview->getDefaultMetric());
 441     if (state & GDK_CONTROL_MASK) {
 442         int ratio_x, ratio_y;
 443         if (fabs (rdimx) > fabs (rdimy)) {
 444             ratio_x = (int) rint (rdimx / rdimy);
 445             ratio_y = 1;
 446         } else {
 447             ratio_x = 1;
 448             ratio_y = (int) rint (rdimy / rdimx);
 449         }
 450         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);
 451     } else {
 452         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);
 453     }
 454     g_string_free(xs, FALSE);
 455     g_string_free(ys, FALSE);
 456 }
 457
 458 static void sp_arc_finish(SPArcContext *ac)
 459 {
 460     ac->_message_context->clear();
 461
 462     if (ac->item != NULL) {
 463         SPDesktop *desktop = SP_EVENT_CONTEXT(ac)->desktop;
 464
 465         SP_OBJECT(ac->item)->updateRepr();
 466
 467         sp_canvas_end_forced_full_redraws(desktop->canvas);
 468
 469         sp_desktop_selection(desktop)->set(ac->item);
 470         sp_document_done(sp_desktop_document(desktop), SP_VERB_CONTEXT_ARC,
 471                          _("Create ellipse"));
 472
 473         ac->item = NULL;
 474     }
 475 }
 476
 477
 478 /*
 479   Local Variables:
 480   mode:c++
 481   c-file-style:"stroustrup"
 482   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 483   indent-tabs-mode:nil
 484   fill-column:99
 485   End:
 486 */
 487 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :