src/event-context.cpp

   1 #define __SP_EVENT_CONTEXT_C__
   2
   3 /** \file
   4  * Main event handling, and related helper functions.
   5  *
   6  * Authors:
   7  *   Lauris Kaplinski <lauris@kaplinski.com>
   8  *   Frank Felfe <innerspace@iname.com>
   9  *   bulia byak <buliabyak@users.sf.net>
  10  *
  11  * Copyright (C) 1999-2005 authors
  12  * Copyright (C) 2001-2002 Ximian, Inc.
  13  *
  14  * Released under GNU GPL, read the file 'COPYING' for more information
  15  */
  16
  17 /** \class SPEventContext
  18  * SPEventContext is an abstract base class of all tools. As the name
  19  * indicates, event context implementations process UI events (mouse
  20  * movements and keypresses) and take actions (like creating or modifying
  21  * objects).  There is one event context implementation for each tool,
  22  * plus few abstract base classes. Writing a new tool involves
  23  * subclassing SPEventContext.
  24  */
  25
  26 #ifdef HAVE_CONFIG_H
  27 # include "config.h"
  28 #endif
  29
  30 #include <gdk/gdkkeysyms.h>
  31 #include <gtk/gtkmain.h>
  32 #include <gtk/gtkmenu.h>
  33 #include <glibmm/i18n.h>
  34
  35 #include "display/sp-canvas.h"
  36 #include "xml/node-event-vector.h"
  37 #include "sp-cursor.h"
  38 #include "shortcuts.h"
  39 #include "desktop.h"
  40 #include "desktop-handles.h"
  41 #include "selection.h"
  42 #include "file.h"
  43 #include "interface.h"
  44 #include "macros.h"
  45 #include "tools-switch.h"
  46 #include "prefs-utils.h"
  47 #include "message-context.h"
  48 #include "gradient-drag.h"
  49 #include "object-edit.h"
  50 #include "attributes.h"
  51 #include "rubberband.h"
  52 #include "selcue.h"
  53
  54 #include "event-context.h"
  55
  56 static void sp_event_context_class_init(SPEventContextClass *klass);
  57 static void sp_event_context_init(SPEventContext *event_context);
  58 static void sp_event_context_dispose(GObject *object);
  59
  60 static void sp_event_context_private_setup(SPEventContext *ec);
  61 static gint sp_event_context_private_root_handler(SPEventContext *event_context, GdkEvent *event);
  62 static gint sp_event_context_private_item_handler(SPEventContext *event_context, SPItem *item, GdkEvent *event);
  63
  64 static void set_event_location(SPDesktop * desktop, GdkEvent * event);
  65
  66 static GObjectClass *parent_class;
  67
  68 // globals for temporary switching to selector by space
  69 static bool selector_toggled = FALSE;
  70 static int switch_selector_to = 0;
  71
  72 static gint xp = 0, yp = 0; // where drag started
  73 static gint tolerance = 0;
  74 static bool within_tolerance = false;
  75
  76 // globals for keeping track of keyboard scroll events in order to accelerate
  77 static guint32 scroll_event_time = 0;
  78 static gdouble scroll_multiply = 1;
  79 static guint scroll_keyval = 0;
  80
  81 /**
  82  * Registers the SPEventContext class with Glib and returns its type number.
  83  */
  84 GType
  85 sp_event_context_get_type(void)
  86 {
  87     static GType type = 0;
  88     if (!type) {
  89         GTypeInfo info = {
  90             sizeof(SPEventContextClass),
  91             NULL, NULL,
  92             (GClassInitFunc) sp_event_context_class_init,
  93             NULL, NULL,
  94             sizeof(SPEventContext),
  95             4,
  96             (GInstanceInitFunc) sp_event_context_init,
  97             NULL,    /* value_table */
  98         };
  99         type = g_type_register_static(G_TYPE_OBJECT, "SPEventContext", &info, (GTypeFlags)0);
 100     }
 101     return type;
 102 }
 103
 104 /**
 105  * Callback to set up the SPEventContext vtable.
 106  */
 107 static void
 108 sp_event_context_class_init(SPEventContextClass *klass)
 109 {
 110     GObjectClass *object_class;
 111
 112     object_class = (GObjectClass *) klass;
 113
 114     parent_class = (GObjectClass*)g_type_class_peek_parent(klass);
 115
 116     object_class->dispose = sp_event_context_dispose;
 117
 118     klass->setup = sp_event_context_private_setup;
 119     klass->root_handler = sp_event_context_private_root_handler;
 120     klass->item_handler = sp_event_context_private_item_handler;
 121 }
 122
 123 /**
 124  * Clears all SPEventContext object members.
 125  */
 126 static void
 127 sp_event_context_init(SPEventContext *event_context)
 128 {
 129     event_context->desktop = NULL;
 130     event_context->cursor = NULL;
 131     event_context->_message_context = NULL;
 132     event_context->_selcue = NULL;
 133     event_context->_grdrag = NULL;
 134     event_context->space_panning = false;
 135 }
 136
 137 /**
 138  * Callback to free and null member variables of SPEventContext object.
 139  */
 140 static void
 141 sp_event_context_dispose(GObject *object)
 142 {
 143     SPEventContext *ec;
 144
 145     ec = SP_EVENT_CONTEXT(object);
 146
 147     if (ec->_message_context) {
 148         delete ec->_message_context;
 149     }
 150
 151     if (ec->cursor != NULL) {
 152         gdk_cursor_unref(ec->cursor);
 153         ec->cursor = NULL;
 154     }
 155
 156     if (ec->desktop) {
 157         ec->desktop = NULL;
 158     }
 159
 160     if (ec->prefs_repr) {
 161         sp_repr_remove_listener_by_data(ec->prefs_repr, ec);
 162         Inkscape::GC::release(ec->prefs_repr);
 163         ec->prefs_repr = NULL;
 164     }
 165
 166     G_OBJECT_CLASS(parent_class)->dispose(object);
 167 }
 168
 169 /**
 170  * Recreates and draws cursor on desktop related to SPEventContext.
 171  */
 172 void
 173 sp_event_context_update_cursor(SPEventContext *ec)
 174 {
 175     GtkWidget *w = GTK_WIDGET(sp_desktop_canvas(ec->desktop));
 176     if (w->window) {
 177         /* fixme: */
 178         if (ec->cursor_shape) {
 179             GdkBitmap *bitmap = NULL;
 180             GdkBitmap *mask = NULL;
 181             sp_cursor_bitmap_and_mask_from_xpm(&bitmap, &mask, ec->cursor_shape);
 182             if ((bitmap != NULL) && (mask != NULL)) {
 183                 if (ec->cursor)
 184                     gdk_cursor_unref (ec->cursor);
 185                 ec->cursor = gdk_cursor_new_from_pixmap(bitmap, mask,
 186                                                         &w->style->black,
 187                                                         &w->style->white,
 188                                                         ec->hot_x, ec->hot_y);
 189                 g_object_unref (bitmap);
 190                 g_object_unref (mask);
 191             }
 192         }
 193         gdk_window_set_cursor(w->window, ec->cursor);
 194     }
 195     ec->desktop->waiting_cursor = false;
 196 }
 197
 198 /**
 199  * Callback that gets called on initialization of SPEventContext object.
 200  * Redraws mouse cursor, at the moment.
 201  */
 202 static void
 203 sp_event_context_private_setup(SPEventContext *ec)
 204 {
 205     sp_event_context_update_cursor(ec);
 206 }
 207
 208 /**
 209  * \brief   Gobbles next key events on the queue with the same keyval and mask. Returns the number of events consumed.
 210  */
 211 gint gobble_key_events(guint keyval, gint mask)
 212 {
 213     GdkEvent *event_next;
 214     gint i = 0;
 215
 216     event_next = gdk_event_get();
 217     // while the next event is also a key notify with the same keyval and mask,
 218     while (event_next && event_next->type == GDK_KEY_PRESS
 219            && event_next->key.keyval == keyval
 220            && (event_next->key.state & mask)) {
 221         // kill it
 222         gdk_event_free(event_next);
 223         // get next
 224         event_next = gdk_event_get();
 225         i ++;
 226     }
 227     // otherwise, put it back onto the queue
 228     if (event_next) gdk_event_put(event_next);
 229
 230     return i;
 231 }
 232
 233 /**
 234  * \brief   Gobbles next motion notify events on the queue with the same mask. Returns the number of events consumed.
 235 */
 236 gint gobble_motion_events(gint mask)
 237 {
 238     GdkEvent *event_next;
 239     gint i = 0;
 240
 241     event_next = gdk_event_get();
 242     // while the next event is also a key notify with the same keyval and mask,
 243     while (event_next && event_next->type == GDK_MOTION_NOTIFY
 244            && (event_next->motion.state & mask)) {
 245         // kill it
 246         gdk_event_free(event_next);
 247         // get next
 248         event_next = gdk_event_get();
 249         i ++;
 250     }
 251     // otherwise, put it back onto the queue
 252     if (event_next) gdk_event_put(event_next);
 253
 254     return i;
 255 }
 256
 257 /**
 258  * Toggles current tool between active tool and selector tool.
 259  * Subroutine of sp_event_context_private_root_handler().
 260  */
 261 static void
 262 sp_toggle_selector(SPDesktop *dt)
 263 {
 264     if (!dt->event_context) return;
 265
 266     if (tools_isactive(dt, TOOLS_SELECT)) {
 267         if (selector_toggled) {
 268             if (switch_selector_to) tools_switch (dt, switch_selector_to);
 269             selector_toggled = FALSE;
 270         } else return;
 271     } else {
 272         selector_toggled = TRUE;
 273         switch_selector_to = tools_active(dt);
 274         tools_switch (dt, TOOLS_SELECT);
 275     }
 276 }
 277
 278 /**
 279  * Calculates and keeps track of scroll acceleration.
 280  * Subroutine of sp_event_context_private_root_handler().
 281  */
 282 static gdouble accelerate_scroll(GdkEvent *event, gdouble acceleration, SPCanvas */*canvas*/)
 283 {
 284     guint32 time_diff = ((GdkEventKey *) event)->time - scroll_event_time;
 285
 286     /* key pressed within 500ms ? (1/2 second) */
 287     if (time_diff > 500 || event->key.keyval != scroll_keyval) {
 288         scroll_multiply = 1; // abort acceleration
 289     } else {
 290         scroll_multiply += acceleration; // continue acceleration
 291     }
 292
 293     scroll_event_time = ((GdkEventKey *) event)->time;
 294     scroll_keyval = event->key.keyval;
 295
 296     return scroll_multiply;
 297 }
 298
 299 /**
 300  * Main event dispatch, gets called from Gdk.
 301  */
 302 static gint sp_event_context_private_root_handler(SPEventContext *event_context, GdkEvent *event)
 303 {
 304     static NR::Point button_w;
 305     static unsigned int panning = 0;
 306     static unsigned int zoom_rb = 0;
 307
 308     SPDesktop *desktop = event_context->desktop;
 309
 310     tolerance = prefs_get_int_attribute_limited(
 311             "options.dragtolerance","value", 0, 0, 100);
 312     double const zoom_inc = prefs_get_double_attribute_limited(
 313             "options.zoomincrement", "value", M_SQRT2, 1.01, 10);
 314     double const acceleration = prefs_get_double_attribute_limited(
 315             "options.scrollingacceleration", "value", 0, 0, 6);
 316     int const key_scroll = prefs_get_int_attribute_limited(
 317             "options.keyscroll", "value", 10, 0, 1000);
 318     int const wheel_scroll = prefs_get_int_attribute_limited(
 319             "options.wheelscroll", "value", 40, 0, 1000);
 320
 321     gint ret = FALSE;
 322
 323     switch (event->type) {
 324         case GDK_2BUTTON_PRESS:
 325             if (panning) {
 326                 panning = 0;
 327                 sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate),
 328                         event->button.time);
 329                 ret = TRUE;
 330             } else {
 331                 /* sp_desktop_dialog(); */
 332             }
 333             break;
 334         case GDK_BUTTON_PRESS:
 335
 336             // save drag origin
 337             xp = (gint) event->button.x;
 338             yp = (gint) event->button.y;
 339             within_tolerance = true;
 340
 341             button_w = NR::Point(event->button.x, event->button.y);
 342
 343             switch (event->button.button) {
 344                 case 1:
 345                     if (event_context->space_panning) {
 346                         panning = 1;
 347                         sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 348                             GDK_KEY_RELEASE_MASK | GDK_BUTTON_RELEASE_MASK | GDK_POINTER_MOTION_MASK,
 349                             NULL, event->button.time-1);
 350                         ret = TRUE;
 351                     }
 352                     break;
 353                 case 2:
 354                     if (event->button.state == GDK_SHIFT_MASK) {
 355                         zoom_rb = 2;
 356                     } else {
 357                         panning = 2;
 358                         sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 359                             GDK_BUTTON_RELEASE_MASK | GDK_POINTER_MOTION_MASK,
 360                             NULL, event->button.time-1);
 361                     }
 362                     ret = TRUE;
 363                     break;
 364                 case 3:
 365                     if (event->button.state & GDK_SHIFT_MASK
 366                             || event->button.state & GDK_CONTROL_MASK) {
 367                         panning = 3;
 368                         sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 369                                 GDK_BUTTON_RELEASE_MASK | GDK_POINTER_MOTION_MASK,
 370                                 NULL, event->button.time);
 371                         ret = TRUE;
 372                     } else {
 373                         sp_event_root_menu_popup(desktop, NULL, event);
 374                     }
 375                     break;
 376                 default:
 377                     break;
 378             }
 379             break;
 380         case GDK_MOTION_NOTIFY:
 381             if (panning) {
 382                 if ((panning == 2 && !(event->motion.state & GDK_BUTTON2_MASK))
 383                         || (panning == 1 && !(event->motion.state & GDK_BUTTON1_MASK))
 384                         || (panning == 3 && !(event->motion.state & GDK_BUTTON3_MASK))
 385                    ) {
 386                     /* Gdk seems to lose button release for us sometimes :-( */
 387                     panning = 0;
 388                     sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate),
 389                             event->button.time);
 390                     ret = TRUE;
 391                 } else {
 392                     if ( within_tolerance
 393                          && ( abs( (gint) event->motion.x - xp ) < tolerance )
 394                          && ( abs( (gint) event->motion.y - yp ) < tolerance ))
 395                     {
 396                         // do not drag if we're within tolerance from origin
 397                         break;
 398                     }
 399                     // Once the user has moved farther than tolerance from
 400                     // the original location (indicating they intend to move
 401                     // the object, not click), then always process the motion
 402                     // notify coordinates as given (no snapping back to origin)
 403                     within_tolerance = false;
 404
 405                     // gobble subsequent motion events to prevent "sticking"
 406                     // when scrolling is slow
 407                     gobble_motion_events(panning == 2 ?
 408                                          GDK_BUTTON2_MASK :
 409                                          (panning == 1 ? GDK_BUTTON1_MASK : GDK_BUTTON3_MASK));
 410
 411                     NR::Point const motion_w(event->motion.x, event->motion.y);
 412                     NR::Point const moved_w( motion_w - button_w );
 413                     event_context->desktop->scroll_world(moved_w, true); // we're still scrolling, do not redraw
 414                     ret = TRUE;
 415                 }
 416             } else if (zoom_rb) {
 417                 NR::Point const motion_w(event->motion.x, event->motion.y);
 418                 NR::Point const motion_dt(desktop->w2d(motion_w));
 419
 420                 if ( within_tolerance
 421                      && ( abs( (gint) event->motion.x - xp ) < tolerance )
 422                      && ( abs( (gint) event->motion.y - yp ) < tolerance ) ) {
 423                     break; // do not drag if we're within tolerance from origin
 424                 }
 425                 // Once the user has moved farther than tolerance from the original location
 426                 // (indicating they intend to move the object, not click), then always process the
 427                 // motion notify coordinates as given (no snapping back to origin)
 428                 within_tolerance = false;
 429
 430                 if (Inkscape::Rubberband::get()->is_started()) {
 431                     Inkscape::Rubberband::get()->move(motion_dt);
 432                 } else {
 433                     Inkscape::Rubberband::get()->start(desktop, motion_dt);
 434                 }
 435                 if (zoom_rb == 2)
 436                     gobble_motion_events(GDK_BUTTON2_MASK);
 437             }
 438             break;
 439         case GDK_BUTTON_RELEASE:
 440             xp = yp = 0;
 441             if (within_tolerance && (panning || zoom_rb)) {
 442                 zoom_rb = 0;
 443                 if (panning) {
 444                     panning = 0;
 445                     sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate),
 446                                       event->button.time);
 447                 }
 448                 NR::Point const event_w(event->button.x, event->button.y);
 449                 NR::Point const event_dt(desktop->w2d(event_w));
 450                 desktop->zoom_relative_keep_point(event_dt,
 451                           (event->button.state & GDK_SHIFT_MASK) ? 1/zoom_inc : zoom_inc);
 452                 desktop->updateNow();
 453                 ret = TRUE;
 454             } else if (panning == event->button.button) {
 455                 panning = 0;
 456                 sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate),
 457                                       event->button.time);
 458
 459                 // in slow complex drawings, some of the motion events are lost;
 460                 // to make up for this, we scroll it once again to the button-up event coordinates
 461                 // (i.e. canvas will always get scrolled all the way to the mouse release point,
 462                 // even if few intermediate steps were visible)
 463                 NR::Point const motion_w(event->button.x, event->button.y);
 464                 NR::Point const moved_w( motion_w - button_w );
 465                 event_context->desktop->scroll_world(moved_w);
 466                 desktop->updateNow();
 467                 ret = TRUE;
 468             } else if (zoom_rb == event->button.button) {
 469                 zoom_rb = 0;
 470                 NR::Maybe<NR::Rect> const b = Inkscape::Rubberband::get()->getRectangle();
 471                 Inkscape::Rubberband::get()->stop();
 472                 if (b && !within_tolerance) {
 473                     desktop->set_display_area(*b, 10);
 474                 }
 475                 ret = TRUE;
 476             }
 477             break;
 478         case GDK_KEY_PRESS:
 479             switch (get_group0_keyval(&event->key)) {
 480                 // GDK insists on stealing these keys (F1 for no idea what, tab for cycling widgets
 481                 // in the editing window). So we resteal them back and run our regular shortcut
 482                 // invoker on them.
 483                 unsigned int shortcut;
 484                 case GDK_Tab:
 485                 case GDK_ISO_Left_Tab:
 486                 case GDK_F1:
 487                     shortcut = get_group0_keyval(&event->key);
 488                     if (event->key.state & GDK_SHIFT_MASK)
 489                         shortcut |= SP_SHORTCUT_SHIFT_MASK;
 490                     if (event->key.state & GDK_CONTROL_MASK)
 491                         shortcut |= SP_SHORTCUT_CONTROL_MASK;
 492                     if (event->key.state & GDK_MOD1_MASK)
 493                         shortcut |= SP_SHORTCUT_ALT_MASK;
 494                     ret = sp_shortcut_invoke(shortcut, desktop);
 495                     break;
 496
 497                 case GDK_W:
 498                 case GDK_w:
 499                 case GDK_F4:
 500                     /* Close view */
 501                     if (MOD__CTRL_ONLY) {
 502                         sp_ui_close_view(NULL);
 503                         ret = TRUE;
 504                     }
 505                     break;
 506                 case GDK_Left: // Ctrl Left
 507                 case GDK_KP_Left:
 508                 case GDK_KP_4:
 509                     if (MOD__CTRL_ONLY) {
 510                         int i = (int) floor(key_scroll * accelerate_scroll(event, acceleration, sp_desktop_canvas(desktop)));
 511                         gobble_key_events(get_group0_keyval(&event->key),
 512                                 GDK_CONTROL_MASK);
 513                         event_context->desktop->scroll_world(i, 0);
 514                         ret = TRUE;
 515                     }
 516                     break;
 517                 case GDK_Up: // Ctrl Up
 518                 case GDK_KP_Up:
 519                 case GDK_KP_8:
 520                     if (MOD__CTRL_ONLY) {
 521                         int i = (int) floor(key_scroll * accelerate_scroll(event, acceleration, sp_desktop_canvas(desktop)));
 522                         gobble_key_events(get_group0_keyval(&event->key),
 523                                 GDK_CONTROL_MASK);
 524                         event_context->desktop->scroll_world(0, i);
 525                         ret = TRUE;
 526                     }
 527                     break;
 528                 case GDK_Right: // Ctrl Right
 529                 case GDK_KP_Right:
 530                 case GDK_KP_6:
 531                     if (MOD__CTRL_ONLY) {
 532                         int i = (int) floor(key_scroll * accelerate_scroll(event, acceleration, sp_desktop_canvas(desktop)));
 533                         gobble_key_events(get_group0_keyval(&event->key),
 534                                 GDK_CONTROL_MASK);
 535                         event_context->desktop->scroll_world(-i, 0);
 536                         ret = TRUE;
 537                     }
 538                     break;
 539                 case GDK_Down: // Ctrl Down
 540                 case GDK_KP_Down:
 541                 case GDK_KP_2:
 542                     if (MOD__CTRL_ONLY) {
 543                         int i = (int) floor(key_scroll * accelerate_scroll(event, acceleration, sp_desktop_canvas(desktop)));
 544                         gobble_key_events(get_group0_keyval(&event->key),
 545                                 GDK_CONTROL_MASK);
 546                         event_context->desktop->scroll_world(0, -i);
 547                         ret = TRUE;
 548                     }
 549                     break;
 550                 case GDK_F10:
 551                     if (MOD__SHIFT_ONLY) {
 552                         sp_event_root_menu_popup(desktop, NULL, event);
 553                         ret= TRUE;
 554                     }
 555                     break;
 556                 case GDK_space:
 557                     if (prefs_get_int_attribute("options.spacepans","value", 0) == 1) {
 558                         event_context->space_panning = true;
 559                         event_context->_message_context->set(Inkscape::INFORMATION_MESSAGE, _("<b>Space+mouse drag</b> to pan canvas"));
 560                         ret= TRUE;
 561                     } else {
 562                         sp_toggle_selector(desktop);
 563                         ret= TRUE;
 564                     }
 565                     break;
 566                 case GDK_z:
 567                 case GDK_Z:
 568                     if (MOD__ALT_ONLY) {
 569                         desktop->zoom_grab_focus();
 570                         ret = TRUE;
 571                     }
 572                     break;
 573                 default:
 574                     break;
 575             }
 576             break;
 577         case GDK_KEY_RELEASE:
 578             switch (get_group0_keyval(&event->key)) {
 579                 case GDK_space:
 580                     if (event_context->space_panning) {
 581                         event_context->space_panning = false;
 582                         event_context->_message_context->clear();
 583                         if (panning == 1) {
 584                             panning = 0;
 585                             sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate),
 586                                   event->key.time);
 587                             desktop->updateNow();
 588                         }
 589                         ret= TRUE;
 590                     }
 591                     break;
 592                 default:
 593                     break;
 594             }
 595             break;
 596         case GDK_SCROLL:
 597         {
 598             bool ctrl = (event->scroll.state & GDK_CONTROL_MASK);
 599             bool wheelzooms = (prefs_get_int_attribute("options.wheelzooms","value", 0) == 1);
 600             /* shift + wheel, pan left--right */
 601             if (event->scroll.state & GDK_SHIFT_MASK) {
 602                 switch (event->scroll.direction) {
 603                     case GDK_SCROLL_UP:
 604                         desktop->scroll_world(wheel_scroll, 0);
 605                         break;
 606                     case GDK_SCROLL_DOWN:
 607                         desktop->scroll_world(-wheel_scroll, 0);
 608                         break;
 609                     default:
 610                         break;
 611                 }
 612
 613                 /* ctrl + wheel, zoom in--out */
 614             } else if ((ctrl && !wheelzooms) || (!ctrl && wheelzooms)) {
 615                 double rel_zoom;
 616                 switch (event->scroll.direction) {
 617                     case GDK_SCROLL_UP:
 618                         rel_zoom = zoom_inc;
 619                         break;
 620                     case GDK_SCROLL_DOWN:
 621                         rel_zoom = 1 / zoom_inc;
 622                         break;
 623                     default:
 624                         rel_zoom = 0.0;
 625                         break;
 626                 }
 627                 if (rel_zoom != 0.0) {
 628                     NR::Point const scroll_dt = desktop->point();
 629                     desktop->zoom_relative_keep_point(scroll_dt, rel_zoom);
 630                 }
 631
 632                 /* no modifier, pan up--down (left--right on multiwheel mice?) */
 633             } else {
 634                 switch (event->scroll.direction) {
 635                     case GDK_SCROLL_UP:
 636                         desktop->scroll_world(0, wheel_scroll);
 637                         break;
 638                     case GDK_SCROLL_DOWN:
 639                         desktop->scroll_world(0, -wheel_scroll);
 640                         break;
 641                     case GDK_SCROLL_LEFT:
 642                         desktop->scroll_world(wheel_scroll, 0);
 643                         break;
 644                     case GDK_SCROLL_RIGHT:
 645                         desktop->scroll_world(-wheel_scroll, 0);
 646                         break;
 647                 }
 648             }
 649             break;
 650         }
 651         default:
 652             break;
 653     }
 654
 655     return ret;
 656 }
 657
 658 /**
 659  * Handles item specific events. Gets called from Gdk.
 660  *
 661  * Only reacts to right mouse button at the moment.
 662  * \todo Fixme: do context sensitive popup menu on items.
 663  */
 664 gint
 665 sp_event_context_private_item_handler(SPEventContext *ec, SPItem *item, GdkEvent *event)
 666 {
 667     int ret = FALSE;
 668
 669     switch (event->type) {
 670         case GDK_BUTTON_PRESS:
 671             if ((event->button.button == 3)
 672                     && !(event->button.state & GDK_SHIFT_MASK || event->button.state & GDK_CONTROL_MASK)) {
 673                 sp_event_root_menu_popup(ec->desktop, item, event);
 674                 ret = TRUE;
 675             }
 676             break;
 677         default:
 678             break;
 679     }
 680
 681     return ret;
 682 }
 683
 684 /**
 685  * Gets called when attribute changes value.
 686  */
 687 static void
 688 sp_ec_repr_attr_changed(Inkscape::XML::Node */*prefs_repr*/, gchar const *key, gchar const */*oldval*/, gchar const *newval,
 689                         bool /*is_interactive*/, gpointer data)
 690 {
 691     SPEventContext *ec;
 692
 693     ec = SP_EVENT_CONTEXT(data);
 694
 695     if (((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->set) {
 696         ((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->set(ec, key, newval);
 697     }
 698 }
 699
 700 Inkscape::XML::NodeEventVector sp_ec_event_vector = {
 701     NULL, /* Child added */
 702     NULL, /* Child removed */
 703     sp_ec_repr_attr_changed,
 704     NULL, /* Content changed */
 705     NULL /* Order changed */
 706 };
 707
 708 /**
 709  * Creates new SPEventContext object and calls its virtual setup() function.
 710  */
 711 SPEventContext *
 712 sp_event_context_new(GType type, SPDesktop *desktop, Inkscape::XML::Node *prefs_repr, unsigned int key)
 713 {
 714     g_return_val_if_fail(g_type_is_a(type, SP_TYPE_EVENT_CONTEXT), NULL);
 715     g_return_val_if_fail(desktop != NULL, NULL);
 716
 717     SPEventContext *const ec = (SPEventContext*)g_object_new(type, NULL);
 718
 719     ec->desktop = desktop;
 720     ec->_message_context = new Inkscape::MessageContext(desktop->messageStack());
 721     ec->key = key;
 722     ec->prefs_repr = prefs_repr;
 723     if (ec->prefs_repr) {
 724         Inkscape::GC::anchor(ec->prefs_repr);
 725         sp_repr_add_listener(ec->prefs_repr, &sp_ec_event_vector, ec);
 726     }
 727
 728     if (((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->setup)
 729         ((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->setup(ec);
 730
 731     return ec;
 732 }
 733
 734 /**
 735  * Finishes SPEventContext.
 736  */
 737 void
 738 sp_event_context_finish(SPEventContext *ec)
 739 {
 740     g_return_if_fail(ec != NULL);
 741     g_return_if_fail(SP_IS_EVENT_CONTEXT(ec));
 742
 743     ec->enableSelectionCue(false);
 744
 745     if (ec->next) {
 746         g_warning("Finishing event context with active link\n");
 747     }
 748
 749     if (((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->finish)
 750         ((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->finish(ec);
 751 }
 752
 753 //-------------------------------member functions
 754
 755 /**
 756  * Enables/disables the SPEventContext's SelCue.
 757  */
 758 void SPEventContext::enableSelectionCue(bool enable) {
 759     if (enable) {
 760         if (!_selcue) {
 761             _selcue = new Inkscape::SelCue(desktop);
 762         }
 763     } else {
 764         delete _selcue;
 765         _selcue = NULL;
 766     }
 767 }
 768
 769 /**
 770  * Enables/disables the SPEventContext's GrDrag.
 771  */
 772 void SPEventContext::enableGrDrag(bool enable) {
 773     if (enable) {
 774         if (!_grdrag) {
 775             _grdrag = new GrDrag(desktop);
 776         }
 777     } else {
 778         if (_grdrag) {
 779             delete _grdrag;
 780             _grdrag = NULL;
 781         }
 782     }
 783 }
 784
 785 /**
 786  * Calls virtual set() function of SPEventContext.
 787  */
 788 void
 789 sp_event_context_read(SPEventContext *ec, gchar const *key)
 790 {
 791     g_return_if_fail(ec != NULL);
 792     g_return_if_fail(SP_IS_EVENT_CONTEXT(ec));
 793     g_return_if_fail(key != NULL);
 794
 795     if (ec->prefs_repr) {
 796         gchar const *val = ec->prefs_repr->attribute(key);
 797         if (((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->set)
 798             ((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->set(ec, key, val);
 799     }
 800 }
 801
 802 /**
 803  * Calls virtual activate() function of SPEventContext.
 804  */
 805 void
 806 sp_event_context_activate(SPEventContext *ec)
 807 {
 808     g_return_if_fail(ec != NULL);
 809     g_return_if_fail(SP_IS_EVENT_CONTEXT(ec));
 810
 811     if (((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->activate)
 812         ((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->activate(ec);
 813 }
 814
 815 /**
 816  * Calls virtual deactivate() function of SPEventContext.
 817  */
 818 void
 819 sp_event_context_deactivate(SPEventContext *ec)
 820 {
 821     g_return_if_fail(ec != NULL);
 822     g_return_if_fail(SP_IS_EVENT_CONTEXT(ec));
 823
 824     if (((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->deactivate)
 825         ((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->deactivate(ec);
 826 }
 827
 828 /**
 829  * Calls virtual root_handler(), the main event handling function.
 830  */
 831 gint
 832 sp_event_context_root_handler(SPEventContext * event_context, GdkEvent * event)
 833 {
 834     gint ret;
 835
 836     ret = ((SPEventContextClass *) G_OBJECT_GET_CLASS(event_context))->root_handler(event_context, event);
 837
 838     set_event_location(event_context->desktop, event);
 839
 840     return ret;
 841 }
 842
 843 /**
 844  * Calls virtual item_handler(), the item event handling function.
 845  */
 846 gint
 847 sp_event_context_item_handler(SPEventContext * event_context, SPItem * item, GdkEvent * event)
 848 {
 849     gint ret;
 850
 851     ret = ((SPEventContextClass *) G_OBJECT_GET_CLASS(event_context))->item_handler(event_context, item, event);
 852
 853     if (! ret) {
 854         ret = sp_event_context_root_handler(event_context, event);
 855     } else {
 856         set_event_location(event_context->desktop, event);
 857     }
 858
 859     return ret;
 860 }
 861
 862 /**
 863  * Emits 'position_set' signal on desktop and shows coordinates on status bar.
 864  */
 865 static void set_event_location(SPDesktop *desktop, GdkEvent *event)
 866 {
 867     if (event->type != GDK_MOTION_NOTIFY) {
 868         return;
 869     }
 870
 871     NR::Point const button_w(event->button.x, event->button.y);
 872     NR::Point const button_dt(desktop->w2d(button_w));
 873     desktop-> setPosition (button_dt);
 874     desktop->set_coordinate_status(button_dt);
 875 }
 876
 877 //-------------------------------------------------------------------
 878 /**
 879  * Create popup menu and tell Gtk to show it.
 880  */
 881 void
 882 sp_event_root_menu_popup(SPDesktop *desktop, SPItem *item, GdkEvent *event)
 883 {
 884     GtkWidget *menu;
 885
 886     /* fixme: This is not what I want but works for now (Lauris) */
 887     if (event->type == GDK_KEY_PRESS) {
 888         item = sp_desktop_selection(desktop)->singleItem();
 889     }
 890     menu = sp_ui_context_menu(desktop, item);
 891     gtk_widget_show(menu);
 892
 893     switch (event->type) {
 894         case GDK_BUTTON_PRESS:
 895             gtk_menu_popup(GTK_MENU(menu), NULL, NULL, 0, NULL, event->button.button, event->button.time);
 896             break;
 897         case GDK_KEY_PRESS:
 898             gtk_menu_popup(GTK_MENU(menu), NULL, NULL, 0, NULL, 0, event->key.time);
 899             break;
 900         default:
 901             break;
 902     }
 903 }
 904
 905 /**
 906  * Show tool context specific modifier tip.
 907  */
 908 void
 909 sp_event_show_modifier_tip(Inkscape::MessageContext *message_context,
 910         GdkEvent *event, gchar const *ctrl_tip, gchar const *shift_tip,
 911         gchar const *alt_tip)
 912 {
 913     guint keyval = get_group0_keyval(&event->key);
 914
 915     bool ctrl = ctrl_tip && (MOD__CTRL
 916             || (keyval == GDK_Control_L)
 917             || (keyval == GDK_Control_R));
 918     bool shift = shift_tip
 919         && (MOD__SHIFT || (keyval == GDK_Shift_L) || (keyval == GDK_Shift_R));
 920     bool alt = alt_tip
 921         && (MOD__ALT
 922                 || (keyval == GDK_Alt_L)
 923                 || (keyval == GDK_Alt_R)
 924                 || (keyval == GDK_Meta_L)
 925                 || (keyval == GDK_Meta_R));
 926
 927     gchar *tip = g_strdup_printf("%s%s%s%s%s",
 928                                  ( ctrl ? ctrl_tip : "" ),
 929                                  ( ctrl && (shift || alt) ? "; " : "" ),
 930                                  ( shift ? shift_tip : "" ),
 931                                  ( (ctrl || shift) && alt ? "; " : "" ),
 932                                  ( alt ? alt_tip : "" ));
 933
 934     if (strlen(tip) > 0) {
 935         message_context->flash(Inkscape::INFORMATION_MESSAGE, tip);
 936     }
 937
 938     g_free(tip);
 939 }
 940
 941 /**
 942  * Return the keyval corresponding to the key event in group 0, i.e.,
 943  * in the main (English) layout.
 944  *
 945  * Use this instead of simply event->keyval, so that your keyboard shortcuts
 946  * work regardless of layouts (e.g., in Cyrillic).
 947  */
 948 guint
 949 get_group0_keyval(GdkEventKey *event)
 950 {
 951     guint keyval = 0;
 952     gdk_keymap_translate_keyboard_state(
 953             gdk_keymap_get_for_display(gdk_display_get_default()),
 954             event->hardware_keycode,
 955             (GdkModifierType) event->state,
 956             0   /*event->key.group*/,
 957             &keyval, NULL, NULL, NULL);
 958     return keyval;
 959 }
 960
 961 /**
 962  * Returns item at point p in desktop.
 963  *
 964  * If state includes alt key mask, cyclically selects under; honors
 965  * into_groups.
 966  */
 967 SPItem *
 968 sp_event_context_find_item (SPDesktop *desktop, NR::Point const p,
 969         bool select_under, bool into_groups)
 970 {
 971     SPItem *item;
 972
 973     if (select_under) {
 974         SPItem *selected_at_point =
 975             desktop->item_from_list_at_point_bottom (desktop->selection->itemList(), p);
 976         item = desktop->item_at_point(p, into_groups, selected_at_point);
 977         if (item == NULL) { // we may have reached bottom, flip over to the top
 978             item = desktop->item_at_point(p, into_groups, NULL);
 979         }
 980     } else
 981         item = desktop->item_at_point(p, into_groups, NULL);
 982
 983     return item;
 984 }
 985
 986 /**
 987  * Returns item if it is under point p in desktop, at any depth; otherwise returns NULL.
 988  *
 989  * Honors into_groups.
 990  */
 991 SPItem *
 992 sp_event_context_over_item (SPDesktop *desktop, SPItem *item, NR::Point const p)
 993 {
 994     GSList *temp = NULL;
 995     temp = g_slist_prepend (temp, item);
 996     SPItem *item_at_point = desktop->item_from_list_at_point_bottom (temp, p);
 997     g_slist_free (temp);
 998
 999     return item_at_point;
1000 }
1001
1002 /**
1003  * Called when SPEventContext subclass node attribute changed.
1004  */
1005 void
1006 ec_shape_event_attr_changed(Inkscape::XML::Node */*shape_repr*/, gchar const *name,
1007                             gchar const */*old_value*/, gchar const */*new_value*/,
1008                             bool const /*is_interactive*/, gpointer const data)
1009 {
1010     if (!name
1011             || !strcmp(name, "style")
1012             || SP_ATTRIBUTE_IS_CSS(sp_attribute_lookup(name))) {
1013         // no need to regenrate knotholder if only style changed
1014         return;
1015     }
1016
1017     SPEventContext *ec = SP_EVENT_CONTEXT(data);
1018
1019     if (ec->shape_knot_holder) {
1020         sp_knot_holder_destroy(ec->shape_knot_holder);
1021     }
1022     ec->shape_knot_holder = NULL;
1023
1024     SPDesktop *desktop = ec->desktop;
1025
1026     SPItem *item = sp_desktop_selection(desktop)->singleItem();
1027
1028     if (item) {
1029         ec->shape_knot_holder = sp_item_knot_holder(item, desktop);
1030     }
1031 }
1032
1033
1034 /*
1035   Local Variables:
1036   mode:c++
1037   c-file-style:"stroustrup"
1038   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1039   indent-tabs-mode:nil
1040   fill-column:99
1041   End:
1042 */
1043 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :