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 <string.h>
  31 #include <gdk/gdkkeysyms.h>
  32 #include <gtk/gtkmain.h>
  33 #include <gtk/gtkmenu.h>
  34 #include <glibmm/i18n.h>
  35 #include <cstring>
  36 #include <string>
  37
  38 #include "display/sp-canvas.h"
  39 #include "xml/node-event-vector.h"
  40 #include "sp-cursor.h"
  41 #include "shortcuts.h"
  42 #include "desktop.h"
  43 #include "desktop-handles.h"
  44 #include "selection.h"
  45 #include "file.h"
  46 #include "interface.h"
  47 #include "macros.h"
  48 #include "tools-switch.h"
  49 #include "prefs-utils.h"
  50 #include "message-context.h"
  51 #include "gradient-drag.h"
  52 #include "object-edit.h"
  53 #include "attributes.h"
  54 #include "rubberband.h"
  55 #include "selcue.h"
  56
  57 #include "event-context.h"
  58
  59 static void sp_event_context_class_init(SPEventContextClass *klass);
  60 static void sp_event_context_init(SPEventContext *event_context);
  61 static void sp_event_context_dispose(GObject *object);
  62
  63 static void sp_event_context_private_setup(SPEventContext *ec);
  64 static gint sp_event_context_private_root_handler(SPEventContext *event_context, GdkEvent *event);
  65 static gint sp_event_context_private_item_handler(SPEventContext *event_context, SPItem *item, GdkEvent *event);
  66
  67 static void set_event_location(SPDesktop * desktop, GdkEvent * event);
  68
  69 static GObjectClass *parent_class;
  70
  71 // globals for temporary switching to selector by space
  72 static bool selector_toggled = FALSE;
  73 static int switch_selector_to = 0;
  74
  75 // globals for temporary switching to dropper by 'D'
  76 static bool dropper_toggled = FALSE;
  77 static int switch_dropper_to = 0;
  78
  79 static gint xp = 0, yp = 0; // where drag started
  80 static gint tolerance = 0;
  81 static bool within_tolerance = false;
  82
  83 // globals for keeping track of keyboard scroll events in order to accelerate
  84 static guint32 scroll_event_time = 0;
  85 static gdouble scroll_multiply = 1;
  86 static guint scroll_keyval = 0;
  87
  88 /**
  89  * Registers the SPEventContext class with Glib and returns its type number.
  90  */
  91 GType
  92 sp_event_context_get_type(void)
  93 {
  94     static GType type = 0;
  95     if (!type) {
  96         GTypeInfo info = {
  97             sizeof(SPEventContextClass),
  98             NULL, NULL,
  99             (GClassInitFunc) sp_event_context_class_init,
 100             NULL, NULL,
 101             sizeof(SPEventContext),
 102             4,
 103             (GInstanceInitFunc) sp_event_context_init,
 104             NULL,    /* value_table */
 105         };
 106         type = g_type_register_static(G_TYPE_OBJECT, "SPEventContext", &info, (GTypeFlags)0);
 107     }
 108     return type;
 109 }
 110
 111 /**
 112  * Callback to set up the SPEventContext vtable.
 113  */
 114 static void
 115 sp_event_context_class_init(SPEventContextClass *klass)
 116 {
 117     GObjectClass *object_class;
 118
 119     object_class = (GObjectClass *) klass;
 120
 121     parent_class = (GObjectClass*)g_type_class_peek_parent(klass);
 122
 123     object_class->dispose = sp_event_context_dispose;
 124
 125     klass->setup = sp_event_context_private_setup;
 126     klass->root_handler = sp_event_context_private_root_handler;
 127     klass->item_handler = sp_event_context_private_item_handler;
 128 }
 129
 130 /**
 131  * Clears all SPEventContext object members.
 132  */
 133 static void
 134 sp_event_context_init(SPEventContext *event_context)
 135 {
 136     event_context->desktop = NULL;
 137     event_context->cursor = NULL;
 138     event_context->_message_context = NULL;
 139     event_context->_selcue = NULL;
 140     event_context->_grdrag = NULL;
 141     event_context->space_panning = false;
 142 }
 143
 144 /**
 145  * Callback to free and null member variables of SPEventContext object.
 146  */
 147 static void
 148 sp_event_context_dispose(GObject *object)
 149 {
 150     SPEventContext *ec;
 151
 152     ec = SP_EVENT_CONTEXT(object);
 153
 154     if (ec->_message_context) {
 155         delete ec->_message_context;
 156     }
 157
 158     if (ec->cursor != NULL) {
 159         gdk_cursor_unref(ec->cursor);
 160         ec->cursor = NULL;
 161     }
 162
 163     if (ec->desktop) {
 164         ec->desktop = NULL;
 165     }
 166
 167     if (ec->prefs_repr) {
 168         sp_repr_remove_listener_by_data(ec->prefs_repr, ec);
 169         Inkscape::GC::release(ec->prefs_repr);
 170         ec->prefs_repr = NULL;
 171     }
 172
 173     G_OBJECT_CLASS(parent_class)->dispose(object);
 174 }
 175
 176 /**
 177  * Recreates and draws cursor on desktop related to SPEventContext.
 178  */
 179 void
 180 sp_event_context_update_cursor(SPEventContext *ec)
 181 {
 182     GtkWidget *w = GTK_WIDGET(sp_desktop_canvas(ec->desktop));
 183     if (w->window) {
 184         /* fixme: */
 185         if (ec->cursor_shape) {
 186             GdkBitmap *bitmap = NULL;
 187             GdkBitmap *mask = NULL;
 188             sp_cursor_bitmap_and_mask_from_xpm(&bitmap, &mask, ec->cursor_shape);
 189             if ((bitmap != NULL) && (mask != NULL)) {
 190                 if (ec->cursor)
 191                     gdk_cursor_unref (ec->cursor);
 192                 ec->cursor = gdk_cursor_new_from_pixmap(bitmap, mask,
 193                                                         &w->style->black,
 194                                                         &w->style->white,
 195                                                         ec->hot_x, ec->hot_y);
 196                 g_object_unref (bitmap);
 197                 g_object_unref (mask);
 198             }
 199         }
 200         gdk_window_set_cursor(w->window, ec->cursor);
 201     }
 202     ec->desktop->waiting_cursor = false;
 203 }
 204
 205 /**
 206  * Callback that gets called on initialization of SPEventContext object.
 207  * Redraws mouse cursor, at the moment.
 208  */
 209 static void
 210 sp_event_context_private_setup(SPEventContext *ec)
 211 {
 212     sp_event_context_update_cursor(ec);
 213 }
 214
 215 /**
 216  * \brief   Gobbles next key events on the queue with the same keyval and mask. Returns the number of events consumed.
 217  */
 218 gint gobble_key_events(guint keyval, gint mask)
 219 {
 220     GdkEvent *event_next;
 221     gint i = 0;
 222
 223     event_next = gdk_event_get();
 224     // while the next event is also a key notify with the same keyval and mask,
 225     while (event_next && (event_next->type == GDK_KEY_PRESS || event_next->type == GDK_KEY_RELEASE)
 226            && event_next->key.keyval == keyval
 227            && (!mask || (event_next->key.state & mask))) {
 228         if (event_next->type == GDK_KEY_PRESS)
 229             i ++;
 230         // kill it
 231         gdk_event_free(event_next);
 232         // get next
 233         event_next = gdk_event_get();
 234     }
 235     // otherwise, put it back onto the queue
 236     if (event_next) gdk_event_put(event_next);
 237
 238     return i;
 239 }
 240
 241 /**
 242  * \brief   Gobbles next motion notify events on the queue with the same mask. Returns the number of events consumed.
 243 */
 244 gint gobble_motion_events(gint mask)
 245 {
 246     GdkEvent *event_next;
 247     gint i = 0;
 248
 249     event_next = gdk_event_get();
 250     // while the next event is also a key notify with the same keyval and mask,
 251     while (event_next && event_next->type == GDK_MOTION_NOTIFY
 252            && (event_next->motion.state & mask)) {
 253         // kill it
 254         gdk_event_free(event_next);
 255         // get next
 256         event_next = gdk_event_get();
 257         i ++;
 258     }
 259     // otherwise, put it back onto the queue
 260     if (event_next) gdk_event_put(event_next);
 261
 262     return i;
 263 }
 264
 265 /**
 266  * Toggles current tool between active tool and selector tool.
 267  * Subroutine of sp_event_context_private_root_handler().
 268  */
 269 static void
 270 sp_toggle_selector(SPDesktop *dt)
 271 {
 272     if (!dt->event_context) return;
 273
 274     if (tools_isactive(dt, TOOLS_SELECT)) {
 275         if (selector_toggled) {
 276             if (switch_selector_to) tools_switch (dt, switch_selector_to);
 277             selector_toggled = FALSE;
 278         } else return;
 279     } else {
 280         selector_toggled = TRUE;
 281         switch_selector_to = tools_active(dt);
 282         tools_switch (dt, TOOLS_SELECT);
 283     }
 284 }
 285
 286 /**
 287  * Toggles current tool between active tool and dropper tool.
 288  * Subroutine of sp_event_context_private_root_handler().
 289  */
 290 static void
 291 sp_toggle_dropper(SPDesktop *dt)
 292 {
 293     if (!dt->event_context) return;
 294
 295     if (tools_isactive(dt, TOOLS_DROPPER)) {
 296         if (dropper_toggled) {
 297             if (switch_dropper_to) tools_switch (dt, switch_dropper_to);
 298             dropper_toggled = FALSE;
 299         } else return;
 300     } else {
 301         dropper_toggled = TRUE;
 302         switch_dropper_to = tools_active(dt);
 303         tools_switch (dt, TOOLS_DROPPER);
 304     }
 305 }
 306
 307 /**
 308  * Calculates and keeps track of scroll acceleration.
 309  * Subroutine of sp_event_context_private_root_handler().
 310  */
 311 static gdouble accelerate_scroll(GdkEvent *event, gdouble acceleration, SPCanvas */*canvas*/)
 312 {
 313     guint32 time_diff = ((GdkEventKey *) event)->time - scroll_event_time;
 314
 315     /* key pressed within 500ms ? (1/2 second) */
 316     if (time_diff > 500 || event->key.keyval != scroll_keyval) {
 317         scroll_multiply = 1; // abort acceleration
 318     } else {
 319         scroll_multiply += acceleration; // continue acceleration
 320     }
 321
 322     scroll_event_time = ((GdkEventKey *) event)->time;
 323     scroll_keyval = event->key.keyval;
 324
 325     return scroll_multiply;
 326 }
 327
 328 /**
 329  * Main event dispatch, gets called from Gdk.
 330  */
 331 static gint sp_event_context_private_root_handler(SPEventContext *event_context, GdkEvent *event)
 332 {
 333     static NR::Point button_w;
 334     static unsigned int panning = 0;
 335     static unsigned int zoom_rb = 0;
 336
 337     SPDesktop *desktop = event_context->desktop;
 338
 339     tolerance = prefs_get_int_attribute_limited(
 340             "options.dragtolerance","value", 0, 0, 100);
 341     double const zoom_inc = prefs_get_double_attribute_limited(
 342             "options.zoomincrement", "value", M_SQRT2, 1.01, 10);
 343     double const acceleration = prefs_get_double_attribute_limited(
 344             "options.scrollingacceleration", "value", 0, 0, 6);
 345     int const key_scroll = prefs_get_int_attribute_limited(
 346             "options.keyscroll", "value", 10, 0, 1000);
 347     int const wheel_scroll = prefs_get_int_attribute_limited(
 348             "options.wheelscroll", "value", 40, 0, 1000);
 349
 350     gint ret = FALSE;
 351
 352     switch (event->type) {
 353         case GDK_2BUTTON_PRESS:
 354             if (panning) {
 355                 panning = 0;
 356                 sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate),
 357                         event->button.time);
 358                 ret = TRUE;
 359             } else {
 360                 /* sp_desktop_dialog(); */
 361             }
 362             break;
 363         case GDK_BUTTON_PRESS:
 364
 365             // save drag origin
 366             xp = (gint) event->button.x;
 367             yp = (gint) event->button.y;
 368             within_tolerance = true;
 369
 370             button_w = NR::Point(event->button.x, event->button.y);
 371
 372             switch (event->button.button) {
 373                 case 1:
 374                     if (event_context->space_panning) {
 375                         panning = 1;
 376                         sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 377                             GDK_KEY_RELEASE_MASK | GDK_BUTTON_RELEASE_MASK | GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK,
 378                             NULL, event->button.time-1);
 379                         ret = TRUE;
 380                     }
 381                     break;
 382                 case 2:
 383                     if (event->button.state == GDK_SHIFT_MASK) {
 384                         zoom_rb = 2;
 385                     } else {
 386                         panning = 2;
 387                         sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 388                             GDK_BUTTON_RELEASE_MASK | GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK,
 389                             NULL, event->button.time-1);
 390                     }
 391                     ret = TRUE;
 392                     break;
 393                 case 3:
 394                     if (event->button.state & GDK_SHIFT_MASK
 395                             || event->button.state & GDK_CONTROL_MASK) {
 396                         panning = 3;
 397                         sp_canvas_item_grab(SP_CANVAS_ITEM(desktop->acetate),
 398                                 GDK_BUTTON_RELEASE_MASK | GDK_POINTER_MOTION_MASK | GDK_POINTER_MOTION_HINT_MASK,
 399                                 NULL, event->button.time);
 400                         ret = TRUE;
 401                     } else {
 402                         sp_event_root_menu_popup(desktop, NULL, event);
 403                     }
 404                     break;
 405                 default:
 406                     break;
 407             }
 408             break;
 409         case GDK_MOTION_NOTIFY:
 410             if (panning) {
 411                 if ((panning == 2 && !(event->motion.state & GDK_BUTTON2_MASK))
 412                         || (panning == 1 && !(event->motion.state & GDK_BUTTON1_MASK))
 413                         || (panning == 3 && !(event->motion.state & GDK_BUTTON3_MASK))
 414                    ) {
 415                     /* Gdk seems to lose button release for us sometimes :-( */
 416                     panning = 0;
 417                     sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate),
 418                             event->button.time);
 419                     ret = TRUE;
 420                 } else {
 421                     if ( within_tolerance
 422                          && ( abs( (gint) event->motion.x - xp ) < tolerance )
 423                          && ( abs( (gint) event->motion.y - yp ) < tolerance ))
 424                     {
 425                         // do not drag if we're within tolerance from origin
 426                         break;
 427                     }
 428                     // Once the user has moved farther than tolerance from
 429                     // the original location (indicating they intend to move
 430                     // the object, not click), then always process the motion
 431                     // notify coordinates as given (no snapping back to origin)
 432                     within_tolerance = false;
 433
 434                     // gobble subsequent motion events to prevent "sticking"
 435                     // when scrolling is slow
 436                     gobble_motion_events(panning == 2 ?
 437                                          GDK_BUTTON2_MASK :
 438                                          (panning == 1 ? GDK_BUTTON1_MASK : GDK_BUTTON3_MASK));
 439
 440                     NR::Point const motion_w(event->motion.x, event->motion.y);
 441                     NR::Point const moved_w( motion_w - button_w );
 442                     event_context->desktop->scroll_world(moved_w, true); // we're still scrolling, do not redraw
 443                     ret = TRUE;
 444                 }
 445             } else if (zoom_rb) {
 446                 NR::Point const motion_w(event->motion.x, event->motion.y);
 447                 NR::Point const motion_dt(desktop->w2d(motion_w));
 448
 449                 if ( within_tolerance
 450                      && ( abs( (gint) event->motion.x - xp ) < tolerance )
 451                      && ( abs( (gint) event->motion.y - yp ) < tolerance ) ) {
 452                     break; // do not drag if we're within tolerance from origin
 453                 }
 454                 // Once the user has moved farther than tolerance from the original location
 455                 // (indicating they intend to move the object, not click), then always process the
 456                 // motion notify coordinates as given (no snapping back to origin)
 457                 within_tolerance = false;
 458
 459                 if (Inkscape::Rubberband::get()->is_started()) {
 460                     Inkscape::Rubberband::get()->move(motion_dt);
 461                 } else {
 462                     Inkscape::Rubberband::get()->start(desktop, motion_dt);
 463                 }
 464                 if (zoom_rb == 2)
 465                     gobble_motion_events(GDK_BUTTON2_MASK);
 466             }
 467             break;
 468         case GDK_BUTTON_RELEASE:
 469             xp = yp = 0;
 470             if (within_tolerance && (panning || zoom_rb)) {
 471                 zoom_rb = 0;
 472                 if (panning) {
 473                     panning = 0;
 474                     sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate),
 475                                       event->button.time);
 476                 }
 477                 NR::Point const event_w(event->button.x, event->button.y);
 478                 NR::Point const event_dt(desktop->w2d(event_w));
 479                 desktop->zoom_relative_keep_point(event_dt,
 480                           (event->button.state & GDK_SHIFT_MASK) ? 1/zoom_inc : zoom_inc);
 481                 desktop->updateNow();
 482                 ret = TRUE;
 483             } else if (panning == event->button.button) {
 484                 panning = 0;
 485                 sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate),
 486                                       event->button.time);
 487
 488                 // in slow complex drawings, some of the motion events are lost;
 489                 // to make up for this, we scroll it once again to the button-up event coordinates
 490                 // (i.e. canvas will always get scrolled all the way to the mouse release point,
 491                 // even if few intermediate steps were visible)
 492                 NR::Point const motion_w(event->button.x, event->button.y);
 493                 NR::Point const moved_w( motion_w - button_w );
 494                 event_context->desktop->scroll_world(moved_w);
 495                 desktop->updateNow();
 496                 ret = TRUE;
 497             } else if (zoom_rb == event->button.button) {
 498                 zoom_rb = 0;
 499                 NR::Maybe<NR::Rect> const b = Inkscape::Rubberband::get()->getRectangle();
 500                 Inkscape::Rubberband::get()->stop();
 501                 if (b && !within_tolerance) {
 502                     desktop->set_display_area(*b, 10);
 503                 }
 504                 ret = TRUE;
 505             }
 506             break;
 507         case GDK_KEY_PRESS:
 508             switch (get_group0_keyval(&event->key)) {
 509                 // GDK insists on stealing these keys (F1 for no idea what, tab for cycling widgets
 510                 // in the editing window). So we resteal them back and run our regular shortcut
 511                 // invoker on them.
 512                 unsigned int shortcut;
 513                 case GDK_Tab:
 514                 case GDK_ISO_Left_Tab:
 515                 case GDK_F1:
 516                     shortcut = get_group0_keyval(&event->key);
 517                     if (event->key.state & GDK_SHIFT_MASK)
 518                         shortcut |= SP_SHORTCUT_SHIFT_MASK;
 519                     if (event->key.state & GDK_CONTROL_MASK)
 520                         shortcut |= SP_SHORTCUT_CONTROL_MASK;
 521                     if (event->key.state & GDK_MOD1_MASK)
 522                         shortcut |= SP_SHORTCUT_ALT_MASK;
 523                     ret = sp_shortcut_invoke(shortcut, desktop);
 524                     break;
 525
 526                 case GDK_D:
 527                 case GDK_d:
 528                     if (!MOD__SHIFT && !MOD__CTRL && !MOD__ALT) {
 529                         sp_toggle_dropper(desktop);
 530                         ret = TRUE;
 531                     }
 532                     break;
 533                 case GDK_W:
 534                 case GDK_w:
 535                 case GDK_F4:
 536                     /* Close view */
 537                     if (MOD__CTRL_ONLY) {
 538                         sp_ui_close_view(NULL);
 539                         ret = TRUE;
 540                     }
 541                     break;
 542                 case GDK_Left: // Ctrl Left
 543                 case GDK_KP_Left:
 544                 case GDK_KP_4:
 545                     if (MOD__CTRL_ONLY) {
 546                         int i = (int) floor(key_scroll * accelerate_scroll(event, acceleration, sp_desktop_canvas(desktop)));
 547                         gobble_key_events(get_group0_keyval(&event->key),
 548                                 GDK_CONTROL_MASK);
 549                         event_context->desktop->scroll_world(i, 0);
 550                         ret = TRUE;
 551                     }
 552                     break;
 553                 case GDK_Up: // Ctrl Up
 554                 case GDK_KP_Up:
 555                 case GDK_KP_8:
 556                     if (MOD__CTRL_ONLY) {
 557                         int i = (int) floor(key_scroll * accelerate_scroll(event, acceleration, sp_desktop_canvas(desktop)));
 558                         gobble_key_events(get_group0_keyval(&event->key),
 559                                 GDK_CONTROL_MASK);
 560                         event_context->desktop->scroll_world(0, i);
 561                         ret = TRUE;
 562                     }
 563                     break;
 564                 case GDK_Right: // Ctrl Right
 565                 case GDK_KP_Right:
 566                 case GDK_KP_6:
 567                     if (MOD__CTRL_ONLY) {
 568                         int i = (int) floor(key_scroll * accelerate_scroll(event, acceleration, sp_desktop_canvas(desktop)));
 569                         gobble_key_events(get_group0_keyval(&event->key),
 570                                 GDK_CONTROL_MASK);
 571                         event_context->desktop->scroll_world(-i, 0);
 572                         ret = TRUE;
 573                     }
 574                     break;
 575                 case GDK_Down: // Ctrl Down
 576                 case GDK_KP_Down:
 577                 case GDK_KP_2:
 578                     if (MOD__CTRL_ONLY) {
 579                         int i = (int) floor(key_scroll * accelerate_scroll(event, acceleration, sp_desktop_canvas(desktop)));
 580                         gobble_key_events(get_group0_keyval(&event->key),
 581                                 GDK_CONTROL_MASK);
 582                         event_context->desktop->scroll_world(0, -i);
 583                         ret = TRUE;
 584                     }
 585                     break;
 586                 case GDK_F10:
 587                     if (MOD__SHIFT_ONLY) {
 588                         sp_event_root_menu_popup(desktop, NULL, event);
 589                         ret= TRUE;
 590                     }
 591                     break;
 592                 case GDK_space:
 593                     if (prefs_get_int_attribute("options.spacepans","value", 0) == 1) {
 594                         event_context->space_panning = true;
 595                         event_context->_message_context->set(Inkscape::INFORMATION_MESSAGE, _("<b>Space+mouse drag</b> to pan canvas"));
 596                         ret= TRUE;
 597                     } else {
 598                         sp_toggle_selector(desktop);
 599                         ret= TRUE;
 600                     }
 601                     break;
 602                 case GDK_z:
 603                 case GDK_Z:
 604                     if (MOD__ALT_ONLY) {
 605                         desktop->zoom_grab_focus();
 606                         ret = TRUE;
 607                     }
 608                     break;
 609                 default:
 610                     break;
 611             }
 612             break;
 613         case GDK_KEY_RELEASE:
 614             switch (get_group0_keyval(&event->key)) {
 615                 case GDK_space:
 616                     if (event_context->space_panning) {
 617                         event_context->space_panning = false;
 618                         event_context->_message_context->clear();
 619                         if (panning == 1) {
 620                             panning = 0;
 621                             sp_canvas_item_ungrab(SP_CANVAS_ITEM(desktop->acetate),
 622                                   event->key.time);
 623                             desktop->updateNow();
 624                         }
 625                         ret= TRUE;
 626                     }
 627                     break;
 628                 default:
 629                     break;
 630             }
 631             break;
 632         case GDK_SCROLL:
 633         {
 634             bool ctrl = (event->scroll.state & GDK_CONTROL_MASK);
 635             bool wheelzooms = (prefs_get_int_attribute("options.wheelzooms","value", 0) == 1);
 636             /* shift + wheel, pan left--right */
 637             if (event->scroll.state & GDK_SHIFT_MASK) {
 638                 switch (event->scroll.direction) {
 639                     case GDK_SCROLL_UP:
 640                         desktop->scroll_world(wheel_scroll, 0);
 641                         break;
 642                     case GDK_SCROLL_DOWN:
 643                         desktop->scroll_world(-wheel_scroll, 0);
 644                         break;
 645                     default:
 646                         break;
 647                 }
 648
 649                 /* ctrl + wheel, zoom in--out */
 650             } else if ((ctrl && !wheelzooms) || (!ctrl && wheelzooms)) {
 651                 double rel_zoom;
 652                 switch (event->scroll.direction) {
 653                     case GDK_SCROLL_UP:
 654                         rel_zoom = zoom_inc;
 655                         break;
 656                     case GDK_SCROLL_DOWN:
 657                         rel_zoom = 1 / zoom_inc;
 658                         break;
 659                     default:
 660                         rel_zoom = 0.0;
 661                         break;
 662                 }
 663                 if (rel_zoom != 0.0) {
 664                     NR::Point const scroll_dt = desktop->point();
 665                     desktop->zoom_relative_keep_point(scroll_dt, rel_zoom);
 666                 }
 667
 668                 /* no modifier, pan up--down (left--right on multiwheel mice?) */
 669             } else {
 670                 switch (event->scroll.direction) {
 671                     case GDK_SCROLL_UP:
 672                         desktop->scroll_world(0, wheel_scroll);
 673                         break;
 674                     case GDK_SCROLL_DOWN:
 675                         desktop->scroll_world(0, -wheel_scroll);
 676                         break;
 677                     case GDK_SCROLL_LEFT:
 678                         desktop->scroll_world(wheel_scroll, 0);
 679                         break;
 680                     case GDK_SCROLL_RIGHT:
 681                         desktop->scroll_world(-wheel_scroll, 0);
 682                         break;
 683                 }
 684             }
 685             break;
 686         }
 687         default:
 688             break;
 689     }
 690
 691     return ret;
 692 }
 693
 694 /**
 695  * Handles item specific events. Gets called from Gdk.
 696  *
 697  * Only reacts to right mouse button at the moment.
 698  * \todo Fixme: do context sensitive popup menu on items.
 699  */
 700 gint
 701 sp_event_context_private_item_handler(SPEventContext *ec, SPItem *item, GdkEvent *event)
 702 {
 703     int ret = FALSE;
 704
 705     switch (event->type) {
 706         case GDK_BUTTON_PRESS:
 707             if ((event->button.button == 3)
 708                     && !(event->button.state & GDK_SHIFT_MASK || event->button.state & GDK_CONTROL_MASK)) {
 709                 sp_event_root_menu_popup(ec->desktop, item, event);
 710                 ret = TRUE;
 711             }
 712             break;
 713         default:
 714             break;
 715     }
 716
 717     return ret;
 718 }
 719
 720 /**
 721  * Gets called when attribute changes value.
 722  */
 723 static void
 724 sp_ec_repr_attr_changed(Inkscape::XML::Node */*prefs_repr*/, gchar const *key, gchar const */*oldval*/, gchar const *newval,
 725                         bool /*is_interactive*/, gpointer data)
 726 {
 727     SPEventContext *ec;
 728
 729     ec = SP_EVENT_CONTEXT(data);
 730
 731     if (((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->set) {
 732         ((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->set(ec, key, newval);
 733     }
 734 }
 735
 736 Inkscape::XML::NodeEventVector sp_ec_event_vector = {
 737     NULL, /* Child added */
 738     NULL, /* Child removed */
 739     sp_ec_repr_attr_changed,
 740     NULL, /* Content changed */
 741     NULL /* Order changed */
 742 };
 743
 744 /**
 745  * Creates new SPEventContext object and calls its virtual setup() function.
 746  */
 747 SPEventContext *
 748 sp_event_context_new(GType type, SPDesktop *desktop, Inkscape::XML::Node *prefs_repr, unsigned int key)
 749 {
 750     g_return_val_if_fail(g_type_is_a(type, SP_TYPE_EVENT_CONTEXT), NULL);
 751     g_return_val_if_fail(desktop != NULL, NULL);
 752
 753     SPEventContext *const ec = (SPEventContext*)g_object_new(type, NULL);
 754
 755     ec->desktop = desktop;
 756     ec->_message_context = new Inkscape::MessageContext(desktop->messageStack());
 757     ec->key = key;
 758     ec->prefs_repr = prefs_repr;
 759     if (ec->prefs_repr) {
 760         Inkscape::GC::anchor(ec->prefs_repr);
 761         sp_repr_add_listener(ec->prefs_repr, &sp_ec_event_vector, ec);
 762     }
 763
 764     if (((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->setup)
 765         ((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->setup(ec);
 766
 767     return ec;
 768 }
 769
 770 /**
 771  * Finishes SPEventContext.
 772  */
 773 void
 774 sp_event_context_finish(SPEventContext *ec)
 775 {
 776     g_return_if_fail(ec != NULL);
 777     g_return_if_fail(SP_IS_EVENT_CONTEXT(ec));
 778
 779     ec->enableSelectionCue(false);
 780
 781     if (ec->next) {
 782         g_warning("Finishing event context with active link\n");
 783     }
 784
 785     if (((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->finish)
 786         ((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->finish(ec);
 787 }
 788
 789 //-------------------------------member functions
 790
 791 /**
 792  * Enables/disables the SPEventContext's SelCue.
 793  */
 794 void SPEventContext::enableSelectionCue(bool enable) {
 795     if (enable) {
 796         if (!_selcue) {
 797             _selcue = new Inkscape::SelCue(desktop);
 798         }
 799     } else {
 800         delete _selcue;
 801         _selcue = NULL;
 802     }
 803 }
 804
 805 /**
 806  * Enables/disables the SPEventContext's GrDrag.
 807  */
 808 void SPEventContext::enableGrDrag(bool enable) {
 809     if (enable) {
 810         if (!_grdrag) {
 811             _grdrag = new GrDrag(desktop);
 812         }
 813     } else {
 814         if (_grdrag) {
 815             delete _grdrag;
 816             _grdrag = NULL;
 817         }
 818     }
 819 }
 820
 821 /**
 822  * Calls virtual set() function of SPEventContext.
 823  */
 824 void
 825 sp_event_context_read(SPEventContext *ec, gchar const *key)
 826 {
 827     g_return_if_fail(ec != NULL);
 828     g_return_if_fail(SP_IS_EVENT_CONTEXT(ec));
 829     g_return_if_fail(key != NULL);
 830
 831     if (ec->prefs_repr) {
 832         gchar const *val = ec->prefs_repr->attribute(key);
 833         if (((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->set)
 834             ((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->set(ec, key, val);
 835     }
 836 }
 837
 838 /**
 839  * Calls virtual activate() function of SPEventContext.
 840  */
 841 void
 842 sp_event_context_activate(SPEventContext *ec)
 843 {
 844     g_return_if_fail(ec != NULL);
 845     g_return_if_fail(SP_IS_EVENT_CONTEXT(ec));
 846
 847     if (((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->activate)
 848         ((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->activate(ec);
 849 }
 850
 851 /**
 852  * Calls virtual deactivate() function of SPEventContext.
 853  */
 854 void
 855 sp_event_context_deactivate(SPEventContext *ec)
 856 {
 857     g_return_if_fail(ec != NULL);
 858     g_return_if_fail(SP_IS_EVENT_CONTEXT(ec));
 859
 860     if (((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->deactivate)
 861         ((SPEventContextClass *) G_OBJECT_GET_CLASS(ec))->deactivate(ec);
 862 }
 863
 864 /**
 865  * Calls virtual root_handler(), the main event handling function.
 866  */
 867 gint
 868 sp_event_context_root_handler(SPEventContext * event_context, GdkEvent * event)
 869 {
 870     gint ret;
 871
 872     ret = ((SPEventContextClass *) G_OBJECT_GET_CLASS(event_context))->root_handler(event_context, event);
 873
 874     set_event_location(event_context->desktop, event);
 875
 876     return ret;
 877 }
 878
 879 /**
 880  * Calls virtual item_handler(), the item event handling function.
 881  */
 882 gint
 883 sp_event_context_item_handler(SPEventContext * event_context, SPItem * item, GdkEvent * event)
 884 {
 885     gint ret;
 886
 887     ret = ((SPEventContextClass *) G_OBJECT_GET_CLASS(event_context))->item_handler(event_context, item, event);
 888
 889     if (! ret) {
 890         ret = sp_event_context_root_handler(event_context, event);
 891     } else {
 892         set_event_location(event_context->desktop, event);
 893     }
 894
 895     return ret;
 896 }
 897
 898 /**
 899  * Emits 'position_set' signal on desktop and shows coordinates on status bar.
 900  */
 901 static void set_event_location(SPDesktop *desktop, GdkEvent *event)
 902 {
 903     if (event->type != GDK_MOTION_NOTIFY) {
 904         return;
 905     }
 906
 907     NR::Point const button_w(event->button.x, event->button.y);
 908     NR::Point const button_dt(desktop->w2d(button_w));
 909     desktop-> setPosition (button_dt);
 910     desktop->set_coordinate_status(button_dt);
 911 }
 912
 913 //-------------------------------------------------------------------
 914 /**
 915  * Create popup menu and tell Gtk to show it.
 916  */
 917 void
 918 sp_event_root_menu_popup(SPDesktop *desktop, SPItem *item, GdkEvent *event)
 919 {
 920     GtkWidget *menu;
 921
 922     /* fixme: This is not what I want but works for now (Lauris) */
 923     if (event->type == GDK_KEY_PRESS) {
 924         item = sp_desktop_selection(desktop)->singleItem();
 925     }
 926     menu = sp_ui_context_menu(desktop, item);
 927     gtk_widget_show(menu);
 928
 929     switch (event->type) {
 930         case GDK_BUTTON_PRESS:
 931             gtk_menu_popup(GTK_MENU(menu), NULL, NULL, 0, NULL, event->button.button, event->button.time);
 932             break;
 933         case GDK_KEY_PRESS:
 934             gtk_menu_popup(GTK_MENU(menu), NULL, NULL, 0, NULL, 0, event->key.time);
 935             break;
 936         default:
 937             break;
 938     }
 939 }
 940
 941 /**
 942  * Show tool context specific modifier tip.
 943  */
 944 void
 945 sp_event_show_modifier_tip(Inkscape::MessageContext *message_context,
 946         GdkEvent *event, gchar const *ctrl_tip, gchar const *shift_tip,
 947         gchar const *alt_tip)
 948 {
 949     guint keyval = get_group0_keyval(&event->key);
 950
 951     bool ctrl = ctrl_tip && (MOD__CTRL
 952             || (keyval == GDK_Control_L)
 953             || (keyval == GDK_Control_R));
 954     bool shift = shift_tip
 955         && (MOD__SHIFT || (keyval == GDK_Shift_L) || (keyval == GDK_Shift_R));
 956     bool alt = alt_tip
 957         && (MOD__ALT
 958                 || (keyval == GDK_Alt_L)
 959                 || (keyval == GDK_Alt_R)
 960                 || (keyval == GDK_Meta_L)
 961                 || (keyval == GDK_Meta_R));
 962
 963     gchar *tip = g_strdup_printf("%s%s%s%s%s",
 964                                  ( ctrl ? ctrl_tip : "" ),
 965                                  ( ctrl && (shift || alt) ? "; " : "" ),
 966                                  ( shift ? shift_tip : "" ),
 967                                  ( (ctrl || shift) && alt ? "; " : "" ),
 968                                  ( alt ? alt_tip : "" ));
 969
 970     if (strlen(tip) > 0) {
 971         message_context->flash(Inkscape::INFORMATION_MESSAGE, tip);
 972     }
 973
 974     g_free(tip);
 975 }
 976
 977 /**
 978  * Return the keyval corresponding to the key event in group 0, i.e.,
 979  * in the main (English) layout.
 980  *
 981  * Use this instead of simply event->keyval, so that your keyboard shortcuts
 982  * work regardless of layouts (e.g., in Cyrillic).
 983  */
 984 guint
 985 get_group0_keyval(GdkEventKey *event)
 986 {
 987     guint keyval = 0;
 988     gdk_keymap_translate_keyboard_state(
 989             gdk_keymap_get_for_display(gdk_display_get_default()),
 990             event->hardware_keycode,
 991             (GdkModifierType) event->state,
 992             0   /*event->key.group*/,
 993             &keyval, NULL, NULL, NULL);
 994     return keyval;
 995 }
 996
 997 /**
 998  * Returns item at point p in desktop.
 999  *
1000  * If state includes alt key mask, cyclically selects under; honors
1001  * into_groups.
1002  */
1003 SPItem *
1004 sp_event_context_find_item (SPDesktop *desktop, NR::Point const p,
1005         bool select_under, bool into_groups)
1006 {
1007     SPItem *item;
1008
1009     if (select_under) {
1010         SPItem *selected_at_point =
1011             desktop->item_from_list_at_point_bottom (desktop->selection->itemList(), p);
1012         item = desktop->item_at_point(p, into_groups, selected_at_point);
1013         if (item == NULL) { // we may have reached bottom, flip over to the top
1014             item = desktop->item_at_point(p, into_groups, NULL);
1015         }
1016     } else
1017         item = desktop->item_at_point(p, into_groups, NULL);
1018
1019     return item;
1020 }
1021
1022 /**
1023  * Returns item if it is under point p in desktop, at any depth; otherwise returns NULL.
1024  *
1025  * Honors into_groups.
1026  */
1027 SPItem *
1028 sp_event_context_over_item (SPDesktop *desktop, SPItem *item, NR::Point const p)
1029 {
1030     GSList *temp = NULL;
1031     temp = g_slist_prepend (temp, item);
1032     SPItem *item_at_point = desktop->item_from_list_at_point_bottom (temp, p);
1033     g_slist_free (temp);
1034
1035     return item_at_point;
1036 }
1037
1038 /**
1039  * Called when SPEventContext subclass node attribute changed.
1040  */
1041 void
1042 ec_shape_event_attr_changed(Inkscape::XML::Node */*shape_repr*/, gchar const *name,
1043                             gchar const */*old_value*/, gchar const */*new_value*/,
1044                             bool const /*is_interactive*/, gpointer const data)
1045 {
1046     if (!name
1047             || !strcmp(name, "style")
1048             || SP_ATTRIBUTE_IS_CSS(sp_attribute_lookup(name))) {
1049         // no need to regenrate knotholder if only style changed
1050         return;
1051     }
1052
1053     SPEventContext *ec = SP_EVENT_CONTEXT(data);
1054
1055     if (ec->shape_knot_holder) {
1056         delete ec->shape_knot_holder;
1057     }
1058     ec->shape_knot_holder = NULL;
1059
1060     SPDesktop *desktop = ec->desktop;
1061
1062     SPItem *item = sp_desktop_selection(desktop)->singleItem();
1063
1064     if (item) {
1065         ec->shape_knot_holder = sp_item_knot_holder(item, desktop);
1066     }
1067 }
1068
1069
1070 /*
1071   Local Variables:
1072   mode:c++
1073   c-file-style:"stroustrup"
1074   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1075   indent-tabs-mode:nil
1076   fill-column:99
1077   End:
1078 */
1079 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :