Pileus Git - grits/blob - src/grits-viewer.c

   1 /*
   2  * Copyright (C) 2009-2011 Andy Spencer <andy753421@gmail.com>
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 /**
  19  * SECTION:grits-viewer
  20  * @short_description: Virtual globe base class
  21  *
  22  * #GritsViewer is the base class for the virtual globe widget. It handles
  23  * everything not directly related to drawing the globe. Plugins and
  24  * applications using the viewer should normally talk to the viewer and not care
  25  * how it is implemented.
  26  */
  27
  28 #include <config.h>
  29 #include <math.h>
  30 #include <gtk/gtk.h>
  31 #include <gdk/gdkkeysyms.h>
  32
  33 #include "grits-marshal.h"
  34 #include "grits-viewer.h"
  35
  36 #include "grits-util.h"
  37
  38
  39 /* Constants */
  40 enum {
  41         SIG_TIME_CHANGED,
  42         SIG_LOCATION_CHANGED,
  43         SIG_ROTATION_CHANGED,
  44         SIG_REFRESH,
  45         SIG_OFFLINE,
  46         NUM_SIGNALS,
  47 };
  48 static guint signals[NUM_SIGNALS];
  49
  50
  51 /***********
  52  * Helpers *
  53  ***********/
  54 /* Misc helpers */
  55 static void _grits_viewer_fix_location(GritsViewer *viewer)
  56 {
  57         while (viewer->location[0] <  -90) viewer->location[0] += 180;
  58         while (viewer->location[0] >   90) viewer->location[0] -= 180;
  59         while (viewer->location[1] < -180) viewer->location[1] += 360;
  60         while (viewer->location[1] >  180) viewer->location[1] -= 360;
  61         viewer->location[2] = ABS(viewer->location[2]);
  62 }
  63
  64 static void _grits_viewer_fix_rotation(GritsViewer *viewer)
  65 {
  66         while (viewer->rotation[0] < -180) viewer->rotation[0] += 360;
  67         while (viewer->rotation[0] >  180) viewer->rotation[0] -= 360;
  68         while (viewer->rotation[1] < -180) viewer->rotation[1] += 360;
  69         while (viewer->rotation[1] >  180) viewer->rotation[1] -= 360;
  70         while (viewer->rotation[2] < -180) viewer->rotation[2] += 360;
  71         while (viewer->rotation[2] >  180) viewer->rotation[2] -= 360;
  72 }
  73
  74 static gboolean _grits_viewer_queue_draw_cb(gpointer _viewer)
  75 {
  76         GritsViewer *viewer = _viewer;
  77         g_mutex_lock(&viewer->draw_lock);
  78         gtk_widget_queue_draw(GTK_WIDGET(viewer));
  79         viewer->draw_source = 0;
  80         g_mutex_unlock(&viewer->draw_lock);
  81         return FALSE;
  82 }
  83
  84 /* Signal helpers */
  85 static void _grits_viewer_emit_location_changed(GritsViewer *viewer)
  86 {
  87         g_signal_emit(viewer, signals[SIG_LOCATION_CHANGED], 0,
  88                         viewer->location[0],
  89                         viewer->location[1],
  90                         viewer->location[2]);
  91 }
  92 static void _grits_viewer_emit_rotation_changed(GritsViewer *viewer)
  93 {
  94         g_signal_emit(viewer, signals[SIG_ROTATION_CHANGED], 0,
  95                         viewer->rotation[0],
  96                         viewer->rotation[1],
  97                         viewer->rotation[2]);
  98 }
  99 static void _grits_viewer_emit_time_changed(GritsViewer *viewer)
 100 {
 101         g_signal_emit(viewer, signals[SIG_TIME_CHANGED], 0,
 102                         viewer->time);
 103 }
 104 static void _grits_viewer_emit_refresh(GritsViewer *viewer)
 105 {
 106         g_signal_emit(viewer, signals[SIG_REFRESH], 0);
 107 }
 108 static void _grits_viewer_emit_offline(GritsViewer *viewer)
 109 {
 110         g_signal_emit(viewer, signals[SIG_OFFLINE], 0,
 111                         viewer->offline);
 112 }
 113
 114 /*************
 115  * Callbacks *
 116  *************/
 117 static gboolean on_key_press(GritsViewer *viewer, GdkEventKey *event, gpointer _)
 118 {
 119         g_debug("GritsViewer: on_key_press - key=%x, state=%x, plus=%x",
 120                         event->keyval, event->state, GDK_KEY_plus);
 121
 122         double lat, lon, elev, pan;
 123         grits_viewer_get_location(viewer, &lat, &lon, &elev);
 124         pan = MIN(elev/(EARTH_R/2), 30);
 125         switch (event->keyval) {
 126         case GDK_KEY_Left:  case GDK_KEY_h: grits_viewer_pan(viewer,  0,  -pan, 0); break;
 127         case GDK_KEY_Down:  case GDK_KEY_j: grits_viewer_pan(viewer, -pan, 0,   0); break;
 128         case GDK_KEY_Up:    case GDK_KEY_k: grits_viewer_pan(viewer,  pan, 0,   0); break;
 129         case GDK_KEY_Right: case GDK_KEY_l: grits_viewer_pan(viewer,  0,   pan, 0); break;
 130         case GDK_KEY_minus: case GDK_KEY_o: grits_viewer_zoom(viewer, 10./9); break;
 131         case GDK_KEY_plus:  case GDK_KEY_i: grits_viewer_zoom(viewer, 9./10); break;
 132         case GDK_KEY_H: grits_viewer_rotate(viewer,  0, 0, -2); break;
 133         case GDK_KEY_J: grits_viewer_rotate(viewer,  2, 0,  0); break;
 134         case GDK_KEY_K: grits_viewer_rotate(viewer, -2, 0,  0); break;
 135         case GDK_KEY_L: grits_viewer_rotate(viewer,  0, 0,  2); break;
 136         }
 137         return FALSE;
 138 }
 139
 140 static gboolean on_scroll(GritsViewer *viewer, GdkEventScroll *event, gpointer _)
 141 {
 142         switch (event->direction) {
 143         case GDK_SCROLL_DOWN: grits_viewer_zoom(viewer, 10./9); break;
 144         case GDK_SCROLL_UP:   grits_viewer_zoom(viewer, 9./10); break;
 145         default: break;
 146         }
 147         return FALSE;
 148 }
 149
 150 enum {
 151         GRITS_DRAG_NONE,
 152         GRITS_DRAG_PAN,
 153         GRITS_DRAG_ZOOM,
 154         GRITS_DRAG_TILT,
 155 };
 156
 157 static gboolean on_button_press(GritsViewer *viewer, GdkEventButton *event, gpointer _)
 158 {
 159         g_debug("GritsViewer: on_button_press - %d", event->button);
 160         gtk_widget_grab_focus(GTK_WIDGET(viewer));
 161         switch (event->button) {
 162         case 1:  viewer->drag_mode = GRITS_DRAG_PAN;  break;
 163         case 2:  viewer->drag_mode = GRITS_DRAG_ZOOM; break;
 164         case 3:  viewer->drag_mode = GRITS_DRAG_TILT; break;
 165         default: viewer->drag_mode = GRITS_DRAG_NONE; break;
 166         }
 167         viewer->drag_x = event->x;
 168         viewer->drag_y = event->y;
 169         return FALSE;
 170 }
 171
 172 static gboolean on_button_release(GritsViewer *viewer, GdkEventButton *event, gpointer _)
 173 {
 174         g_debug("GritsViewer: on_button_release");
 175         viewer->drag_mode = GRITS_DRAG_NONE;
 176         return FALSE;
 177 }
 178
 179 static gboolean on_motion_notify(GritsViewer *viewer, GdkEventMotion *event, gpointer _)
 180 {
 181         gdouble x = viewer->drag_x - event->x;
 182         gdouble y = viewer->drag_y - event->y;
 183         gdouble lat, lon, elev, scale, rx, ry, rz;
 184         grits_viewer_get_location(GRITS_VIEWER(viewer), &lat, &lon, &elev);
 185         grits_viewer_get_rotation(GRITS_VIEWER(viewer), &rx,  &ry,  &rz);
 186         scale = (elev/EARTH_R/14.1) * (sin(deg2rad(ABS(rx)))*4+1);
 187         switch (viewer->drag_mode) {
 188         case GRITS_DRAG_PAN:  grits_viewer_pan(viewer, -y*scale*0.782, x*scale, 0); break;
 189         case GRITS_DRAG_ZOOM: grits_viewer_zoom(viewer, pow(2, -y/500)); break;
 190         case GRITS_DRAG_TILT: grits_viewer_rotate(viewer, y/10, 0, x/10); break;
 191         }
 192         viewer->drag_x = event->x;
 193         viewer->drag_y = event->y;
 194         return FALSE;
 195 }
 196
 197 static void on_view_changed(GritsViewer *viewer,
 198                 gdouble _1, gdouble _2, gdouble _3)
 199 {
 200         grits_viewer_queue_draw(viewer);
 201 }
 202
 203 /***********
 204  * Methods *
 205  ***********/
 206 /**
 207  * grits_viewer_setup:
 208  * @viewer:  the viewer
 209  * @plugins: a plugins store
 210  * @prefs:   a prefs store
 211  *
 212  * This should be called by objects which implement GritsViewer somewhere in their
 213  * constructor.
 214  */
 215 void grits_viewer_setup(GritsViewer *viewer, GritsPlugins *plugins, GritsPrefs *prefs)
 216 {
 217         viewer->plugins = plugins;
 218         viewer->prefs   = prefs;
 219         viewer->offline = grits_prefs_get_boolean(prefs, "grits/offline", NULL);
 220 }
 221
 222 /**
 223  * grits_viewer_set_time:
 224  * @viewer: the viewer
 225  * @time: the time to set the view to
 226  *
 227  * Set the current time for the view
 228  */
 229 void grits_viewer_set_time(GritsViewer *viewer, time_t time)
 230 {
 231         g_assert(GRITS_IS_VIEWER(viewer));
 232         g_debug("GritsViewer: set_time - time=%ld", time);
 233         viewer->time = time;
 234         _grits_viewer_emit_time_changed(viewer);
 235 }
 236
 237 /**
 238  * grits_viewer_get_time:
 239  * @viewer: the viewer
 240  *
 241  * Get the time that is being viewed
 242  *
 243  * Returns: the current time
 244  */
 245 time_t grits_viewer_get_time(GritsViewer *viewer)
 246 {
 247         g_assert(GRITS_IS_VIEWER(viewer));
 248         g_debug("GritsViewer: get_time");
 249         return viewer->time;
 250 }
 251
 252 /**
 253  * grits_viewer_set_location:
 254  * @viewer: the viewer
 255  * @lat:  the new latitude
 256  * @lon:  the new longitude
 257  * @elev: the new elevation
 258  *
 259  * Set the location for the camera
 260  */
 261 void grits_viewer_set_location(GritsViewer *viewer, gdouble lat, gdouble lon, gdouble elev)
 262 {
 263         g_assert(GRITS_IS_VIEWER(viewer));
 264         g_debug("GritsViewer: set_location");
 265         viewer->location[0] = lat;
 266         viewer->location[1] = lon;
 267         viewer->location[2] = elev;
 268         _grits_viewer_fix_location(viewer);
 269         _grits_viewer_emit_location_changed(viewer);
 270 }
 271
 272 /**
 273  * grits_viewer_get_location:
 274  * @viewer: the viewer
 275  * @lat:  the location to store the latitude
 276  * @lon:  the location to store the longitude
 277  * @elev: the location to store the elevation
 278  *
 279  * Get the location of the camera
 280  */
 281 void grits_viewer_get_location(GritsViewer *viewer, gdouble *lat, gdouble *lon, gdouble *elev)
 282 {
 283         g_assert(GRITS_IS_VIEWER(viewer));
 284         //g_debug("GritsViewer: get_location");
 285         *lat  = viewer->location[0];
 286         *lon  = viewer->location[1];
 287         *elev = viewer->location[2];
 288 }
 289
 290 /**
 291  * grits_viewer_pan:
 292  * @viewer: the viewer
 293  * @forward:  distance to move forward in meters
 294  * @right:    distance to move right in meters
 295  * @up:       distance to move up in meters
 296  *
 297  * Pan the location by a number of meters long the surface.
 298  *
 299  * Bugs: the distances are not in meters
 300  * Bugs: panning does not move in strait lines
 301  */
 302 void grits_viewer_pan(GritsViewer *viewer, gdouble forward, gdouble sideways, gdouble up)
 303 {
 304         g_assert(GRITS_IS_VIEWER(viewer));
 305         g_debug("GritsViewer: pan - forward=%8.3f, sideways=%8.3f, up=%8.3f",
 306                         forward, sideways, up);
 307         gdouble dist   = sqrt(forward*forward + sideways*sideways);
 308         gdouble angle1 = deg2rad(viewer->rotation[2]);
 309         gdouble angle2 = atan2(sideways, forward);
 310         gdouble angle  = angle1 + angle2;
 311         /* This isn't accurate, but it's usable */
 312         viewer->location[0] += dist*cos(angle);
 313         viewer->location[1] += dist*sin(angle);
 314         viewer->location[2] += up;
 315         _grits_viewer_fix_location(viewer);
 316         _grits_viewer_emit_location_changed(viewer);
 317 }
 318
 319 /**
 320  * grits_viewer_zoom:
 321  * @viewer: the viewer
 322  * @scale: the scale to multiple the elevation by
 323  *
 324  * Multiple the elevation by a scale.
 325  */
 326 void grits_viewer_zoom(GritsViewer *viewer, gdouble scale)
 327 {
 328         g_assert(GRITS_IS_VIEWER(viewer));
 329         g_debug("GritsViewer: zoom");
 330         viewer->location[2] *= scale;
 331         _grits_viewer_emit_location_changed(viewer);
 332 }
 333
 334 /**
 335  * grits_viewer_set_rotation:
 336  * @viewer: the viewer
 337  * @x: rotation new around the x axes
 338  * @y: rotation new around the y axes
 339  * @z: rotation new around the z axes
 340  *
 341  * Set the rotations in degrees around the x, y, and z axes.
 342  */
 343 void grits_viewer_set_rotation(GritsViewer *viewer, gdouble x, gdouble y, gdouble z)
 344 {
 345         g_assert(GRITS_IS_VIEWER(viewer));
 346         g_debug("GritsViewer: set_rotation");
 347         viewer->rotation[0] = x;
 348         viewer->rotation[1] = y;
 349         viewer->rotation[2] = z;
 350         _grits_viewer_fix_rotation(viewer);
 351         _grits_viewer_emit_rotation_changed(viewer);
 352 }
 353
 354 /**
 355  * grits_viewer_get_rotation:
 356  * @viewer: the viewer
 357  * @x: rotation around the x axes
 358  * @y: rotation around the y axes
 359  * @z: rotation around the z axes
 360  *
 361  * Get the rotations in degrees around the x, y, and z axes.
 362  */
 363 void grits_viewer_get_rotation(GritsViewer *viewer, gdouble *x, gdouble *y, gdouble *z)
 364 {
 365         g_assert(GRITS_IS_VIEWER(viewer));
 366         //g_debug("GritsViewer: get_rotation");
 367         *x = viewer->rotation[0];
 368         *y = viewer->rotation[1];
 369         *z = viewer->rotation[2];
 370 }
 371
 372 /**
 373  * grits_viewer_rotate:
 374  * @viewer: the viewer
 375  * @x: rotation around the x axes
 376  * @y: rotation around the y axes
 377  * @z: rotation around the z axes
 378  *
 379  * Add to the rotation around the x, y, and z axes.
 380  */
 381 void grits_viewer_rotate(GritsViewer *viewer, gdouble x, gdouble y, gdouble z)
 382 {
 383         g_assert(GRITS_IS_VIEWER(viewer));
 384         g_debug("GritsViewer: rotate - x=%.0f, y=%.0f, z=%.0f", x, y, z);
 385         viewer->rotation[0] += x;
 386         viewer->rotation[1] += y;
 387         viewer->rotation[2] += z;
 388         _grits_viewer_fix_rotation(viewer);
 389         _grits_viewer_emit_rotation_changed(viewer);
 390 }
 391
 392 /**
 393  * grits_viewer_refresh:
 394  * @viewer: the viewer
 395  *
 396  * Trigger the refresh signal. This will cause any remote data to be checked for
 397  * updates.
 398  */
 399 void grits_viewer_refresh(GritsViewer *viewer)
 400 {
 401         g_debug("GritsViewer: refresh");
 402         _grits_viewer_emit_refresh(viewer);
 403 }
 404
 405 /**
 406  * grits_viewer_set_offline:
 407  * @viewer: the viewer
 408  * @offline: %TRUE to enter offline mode
 409  *
 410  * Set the offline mode. If @offline is %TRUE, only locally cached data will be
 411  * used.
 412  */
 413 void grits_viewer_set_offline(GritsViewer *viewer, gboolean offline)
 414 {
 415         g_assert(GRITS_IS_VIEWER(viewer));
 416         g_debug("GritsViewer: set_offline - %d", offline);
 417         grits_prefs_set_boolean(viewer->prefs, "grits/offline", offline);
 418         viewer->offline = offline;
 419         _grits_viewer_emit_offline(viewer);
 420 }
 421
 422 /**
 423  * grits_viewer_get_offline:
 424  * @viewer: the viewer
 425  *
 426  * Check if the viewer is in offline mode.
 427  *
 428  * Returns: %TRUE if the viewer is in offline mode.
 429  */
 430 gboolean grits_viewer_get_offline(GritsViewer *viewer)
 431 {
 432         g_assert(GRITS_IS_VIEWER(viewer));
 433         g_debug("GritsViewer: get_offline - %d", viewer->offline);
 434         return viewer->offline;
 435 }
 436
 437 /**
 438  * grits_viewer_queue_draw:
 439  * @viewer: the viewer
 440  *
 441  * Causes the viewer to redraw the screen. This has the safe effect as
 442  * gtk_widget_queue_draw, but is thread safe, and probably faster.
 443  */
 444 void grits_viewer_queue_draw(GritsViewer *viewer)
 445 {
 446         g_mutex_lock(&viewer->draw_lock);
 447         if (!viewer->draw_source)
 448                 viewer->draw_source = g_idle_add_full(G_PRIORITY_HIGH,
 449                                 _grits_viewer_queue_draw_cb, viewer, NULL);
 450         g_mutex_unlock(&viewer->draw_lock);
 451 }
 452
 453 /***********************************
 454  * To be implemented by subclasses *
 455  ***********************************/
 456 /**
 457  * grits_viewer_center_position:
 458  * @viewer: the viewer
 459  * @lat:  the latitude
 460  * @lon:  the longitude
 461  * @elev: the elevation
 462  *
 463  * Center the viewer on a point. This can be used before drawing operations to
 464  * center the items a particular location.
 465  */
 466 void grits_viewer_center_position(GritsViewer *viewer,
 467                 gdouble lat, gdouble lon, gdouble elev)
 468 {
 469         GritsViewerClass *klass = GRITS_VIEWER_GET_CLASS(viewer);
 470         if (!klass->center_position)
 471                 g_warning("GritsViewer: center_position - Unimplemented");
 472         klass->center_position(viewer, lat, lon, elev);
 473 }
 474
 475 /**
 476  * grits_viewer_project:
 477  * @viewer: the viewer
 478  * @lat:  the latitude
 479  * @lon:  the longitude
 480  * @elev: the elevation
 481  * @px:   the project x coordinate
 482  * @py:   the project y coordinate
 483  * @pz:   the project z coordinate
 484  *
 485  * Project a latitude, longitude, elevation point to to x, y, and z coordinates
 486  * in screen space. Useful for drawing orthographic data over a particular point
 487  * in space. E.g. #GritsMarker.
 488  */
 489 void grits_viewer_project(GritsViewer *viewer,
 490                 gdouble lat, gdouble lon, gdouble elev,
 491                 gdouble *px, gdouble *py, gdouble *pz)
 492 {
 493         GritsViewerClass *klass = GRITS_VIEWER_GET_CLASS(viewer);
 494         if (!klass->project)
 495                 g_warning("GritsViewer: project - Unimplemented");
 496         klass->project(viewer, lat, lon, elev, px, py, pz);
 497 }
 498
 499 /**
 500  * grits_viewer_unproject:
 501  * @viewer: the viewer
 502  * @x:    x coordinate in screen space
 503  * @y:    y coordinate in screen space
 504  * @z:    z coordinate in screen space, or -1 to use the value
 505  *        from the depth buffer at x and y as the z value
 506  * @lat:  the latitude
 507  * @lon:  the longitude
 508  * @elev: the elevation
 509  *
 510  * Project a x, y point in screen space to a latitude, longitude, and elevation
 511  * point. Useful for finding the position of the cursor or another on-screen
 512  * object in world coordinates.
 513  */
 514 void grits_viewer_unproject(GritsViewer *viewer,
 515                 gdouble px, gdouble py, gdouble pz,
 516                 gdouble *lat, gdouble *lon, gdouble *elev)
 517 {
 518         GritsViewerClass *klass = GRITS_VIEWER_GET_CLASS(viewer);
 519         if (!klass->unproject)
 520                 g_warning("GritsViewer: unproject - Unimplemented");
 521         klass->unproject(viewer, px, py, pz, lat, lon, elev);
 522 }
 523
 524 /**
 525  * grits_viewer_clear_height_func:
 526  * @viewer: the viewer
 527  *
 528  * Clears the height function for the entire viewer. Useful when an elevation
 529  * plugin is unloaded.
 530  */
 531 void grits_viewer_clear_height_func(GritsViewer *viewer)
 532 {
 533         GritsViewerClass *klass = GRITS_VIEWER_GET_CLASS(viewer);
 534         if (!klass->clear_height_func)
 535                 g_warning("GritsViewer: clear_height_func - Unimplemented");
 536         klass->clear_height_func(viewer);
 537 }
 538
 539 /**
 540  * grits_viewer_set_height_func:
 541  * @viewer:      the viewer
 542  * @bounds:      the area to set the height function for
 543  * @height_func: the height function
 544  * @user_data:   user data to pass to the height function
 545  * @update:      %TRUE if the heights inside the bounds should be updated.
 546  *
 547  * Set the height function to be used for a given part of the surface..
 548  */
 549 void grits_viewer_set_height_func(GritsViewer *viewer, GritsBounds *bounds,
 550                 GritsHeightFunc height_func, gpointer user_data,
 551                 gboolean update)
 552 {
 553         GritsViewerClass *klass = GRITS_VIEWER_GET_CLASS(viewer);
 554         if (!klass->set_height_func)
 555                 g_warning("GritsViewer: set_height_func - Unimplemented");
 556         klass->set_height_func(viewer, bounds, height_func, user_data, update);
 557 }
 558
 559 /**
 560  * grits_viewer_add:
 561  * @viewer: the viewer
 562  * @object: the object to add
 563  * @level:  the level to add the object to
 564  * @sort:   %TRUE if the object should be depth-sorted prior to being drawn
 565  *
 566  * Objects which are added to the viewer will be drawn on subsequent renderings
 567  * if their level of details is adequate.
 568  *
 569  * The @level represents the order the object should be drawn in, this is
 570  * unrelated to the objects actual position in the world.
 571  *
 572  * Semi-transparent objects should set @sort to %TRUE so that they are rendered
 573  * correctly when they overlap other semi-transparent objects.
 574  *
 575  * The viewer steals the objects reference. Call g_object_ref if you plan on
 576  * holding a reference as well.
 577  */
 578 void grits_viewer_add(GritsViewer *viewer, GritsObject *object,
 579                 gint level, gboolean sort)
 580 {
 581         GritsViewerClass *klass = GRITS_VIEWER_GET_CLASS(viewer);
 582         if (!klass->add)
 583                 g_warning("GritsViewer: add - Unimplemented");
 584         object->viewer = viewer;
 585         klass->add(viewer, object, level, sort);
 586 }
 587
 588 /**
 589  * grits_viewer_remove:
 590  * @viewer: the viewer
 591  * @object: the object to remove
 592  *
 593  * Remove an object from the viewer.
 594  */
 595 void grits_viewer_remove(GritsViewer *viewer, GritsObject *object)
 596 {
 597         GritsViewerClass *klass = GRITS_VIEWER_GET_CLASS(viewer);
 598         if (!object->viewer)
 599                 return;
 600         if (!klass->remove)
 601                 g_warning("GritsViewer: remove - Unimplemented");
 602         object->viewer = NULL;
 603         klass->remove(viewer, object);
 604 }
 605
 606 /****************
 607  * GObject code *
 608  ****************/
 609 G_DEFINE_ABSTRACT_TYPE(GritsViewer, grits_viewer, GTK_TYPE_DRAWING_AREA);
 610 static void grits_viewer_init(GritsViewer *viewer)
 611 {
 612         g_debug("GritsViewer: init");
 613         /* Default values */
 614         viewer->time        = time(NULL);
 615         viewer->location[0] = 40;
 616         viewer->location[1] = -100;
 617         viewer->location[2] = EARTH_R;
 618         viewer->rotation[0] = 0;
 619         viewer->rotation[1] = 0;
 620         viewer->rotation[2] = 0;
 621
 622         g_mutex_init(&viewer->draw_lock);
 623
 624         g_object_set(viewer, "can-focus", TRUE, NULL);
 625         gtk_widget_add_events(GTK_WIDGET(viewer),
 626                         GDK_BUTTON_PRESS_MASK |
 627                         GDK_BUTTON_RELEASE_MASK |
 628                         GDK_POINTER_MOTION_MASK |
 629                         GDK_KEY_PRESS_MASK);
 630
 631         g_signal_connect(viewer, "key-press-event",      G_CALLBACK(on_key_press),      NULL);
 632         g_signal_connect(viewer, "scroll-event",         G_CALLBACK(on_scroll),         NULL);
 633
 634         g_signal_connect(viewer, "button-press-event",   G_CALLBACK(on_button_press),   NULL);
 635         g_signal_connect(viewer, "button-release-event", G_CALLBACK(on_button_release), NULL);
 636         g_signal_connect(viewer, "motion-notify-event",  G_CALLBACK(on_motion_notify),  NULL);
 637
 638         g_signal_connect(viewer, "location-changed",     G_CALLBACK(on_view_changed),   NULL);
 639         g_signal_connect(viewer, "rotation-changed",     G_CALLBACK(on_view_changed),   NULL);
 640 }
 641 static void grits_viewer_dispose(GObject *gobject)
 642 {
 643         g_debug("GritsViewer: dispose");
 644         GritsViewer *viewer = GRITS_VIEWER(gobject);
 645         g_mutex_lock(&viewer->draw_lock);
 646         if (viewer->draw_source)
 647                 g_source_remove(viewer->draw_source);
 648         g_mutex_unlock(&viewer->draw_lock);
 649         G_OBJECT_CLASS(grits_viewer_parent_class)->dispose(gobject);
 650 }
 651 static void grits_viewer_finalize(GObject *gobject)
 652 {
 653         g_debug("GritsViewer: finalize");
 654         GritsViewer *viewer = GRITS_VIEWER(gobject);
 655         g_mutex_clear(&viewer->draw_lock);
 656         G_OBJECT_CLASS(grits_viewer_parent_class)->finalize(gobject);
 657         g_debug("GritsViewer: finalize - done");
 658 }
 659 static void grits_viewer_class_init(GritsViewerClass *klass)
 660 {
 661         g_debug("GritsViewer: class_init");
 662         GObjectClass *gobject_class = G_OBJECT_CLASS(klass);
 663         gobject_class->dispose      = grits_viewer_dispose;
 664         gobject_class->finalize     = grits_viewer_finalize;
 665
 666         /**
 667          * GritsViewer::time-changed:
 668          * @viewer: the viewer.
 669          * @time:   the new time.
 670          *
 671          * The ::time-changed signal is emitted when the viewers current time
 672          * changers.
 673          */
 674         signals[SIG_TIME_CHANGED] = g_signal_new(
 675                         "time-changed",
 676                         G_TYPE_FROM_CLASS(gobject_class),
 677                         G_SIGNAL_RUN_LAST,
 678                         0,
 679                         NULL,
 680                         NULL,
 681                         g_cclosure_marshal_VOID__LONG,
 682                         G_TYPE_NONE,
 683                         1,
 684                         G_TYPE_LONG);
 685
 686         /**
 687          * GritsViewer::location-changed:
 688          * @viewer: the viewer.
 689          * @lat:    the new latitude.
 690          * @lon:    the new longitude.
 691          * @elev:   the new elevation.
 692          *
 693          * The ::location-changed signal is emitted when the viewers camera
 694          * location changes.
 695          */
 696         signals[SIG_LOCATION_CHANGED] = g_signal_new(
 697                         "location-changed",
 698                         G_TYPE_FROM_CLASS(gobject_class),
 699                         G_SIGNAL_RUN_LAST,
 700                         0,
 701                         NULL,
 702                         NULL,
 703                         grits_cclosure_marshal_VOID__DOUBLE_DOUBLE_DOUBLE,
 704                         G_TYPE_NONE,
 705                         3,
 706                         G_TYPE_DOUBLE,
 707                         G_TYPE_DOUBLE,
 708                         G_TYPE_DOUBLE);
 709
 710         /**
 711          * GritsViewer::rotation-changed:
 712          * @viewer: the viewer.
 713          * @x: rotation new around the x axes.
 714          * @y: rotation new around the y axes.
 715          * @z: rotation new around the z axes.
 716          *
 717          * The ::rotation-changed signal is emitted when the viewers cameras
 718          * rotation changes.
 719          */
 720         signals[SIG_ROTATION_CHANGED] = g_signal_new(
 721                         "rotation-changed",
 722                         G_TYPE_FROM_CLASS(gobject_class),
 723                         G_SIGNAL_RUN_LAST,
 724                         0,
 725                         NULL,
 726                         NULL,
 727                         grits_cclosure_marshal_VOID__DOUBLE_DOUBLE_DOUBLE,
 728                         G_TYPE_NONE,
 729                         3,
 730                         G_TYPE_DOUBLE,
 731                         G_TYPE_DOUBLE,
 732                         G_TYPE_DOUBLE);
 733
 734         /**
 735          * GritsViewer::refresh:
 736          * @viewer: the viewer.
 737          *
 738          * The ::refresh signal is emitted when a refresh is needed. If you are
 739          * using real-time data from a remote server, you should connect to the
 740          * refresh signal and update the data when necessary.
 741          */
 742         signals[SIG_REFRESH] = g_signal_new(
 743                         "refresh",
 744                         G_TYPE_FROM_CLASS(gobject_class),
 745                         G_SIGNAL_RUN_LAST,
 746                         0,
 747                         NULL,
 748                         NULL,
 749                         g_cclosure_marshal_VOID__VOID,
 750                         G_TYPE_NONE,
 751                         0);
 752
 753         /**
 754          * GritsViewer::offline:
 755          * @viewer:  the viewer.
 756          * @offline: %TRUE if the viewer going offline.
 757          *
 758          * The ::offline signal is emitted when the viewers offline mode
 759          * changes.
 760          */
 761         signals[SIG_OFFLINE] = g_signal_new(
 762                         "offline",
 763                         G_TYPE_FROM_CLASS(gobject_class),
 764                         G_SIGNAL_RUN_LAST,
 765                         0,
 766                         NULL,
 767                         NULL,
 768                         g_cclosure_marshal_VOID__BOOLEAN,
 769                         G_TYPE_NONE,
 770                         1,
 771                         G_TYPE_BOOLEAN);
 772 }