diff options
| -rw-r--r-- | gps.c | 47 |
1 files changed, 45 insertions, 2 deletions
@@ -30,10 +30,53 @@ static void on_close(GtkWidget *widget, gpointer user_data) static gboolean scroll_cb(GtkWidget *widget, GdkEventScroll *event, gpointer data) { OsmGpsMap *map = (OsmGpsMap *)widget; - if (event->direction == GDK_SCROLL_UP) + OsmGpsMapPoint *pt, *lt, *rb, *target; + float target_lat, target_lon; + gint ltx, lty, rbx, rby, target_x, target_y; + gint zoom, max_zoom, min_zoom; + + g_object_get(widget, "max-zoom", &max_zoom, "zoom", &zoom, "min-zoom", &min_zoom, NULL); + + pt = osm_gps_map_point_new_degrees(0.0, 0.0); + lt = osm_gps_map_point_new_degrees(0.0, 0.0); + rb = osm_gps_map_point_new_degrees(0.0, 0.0); + target = osm_gps_map_point_new_degrees(0.0, 0.0); + + osm_gps_map_convert_screen_to_geographic(map, event->x, event->y, pt); + + osm_gps_map_get_bbox(map, lt, rb); + osm_gps_map_convert_geographic_to_screen(map, lt, <x, <y); + osm_gps_map_convert_geographic_to_screen(map, rb, &rbx, &rby); + + if (event->direction == GDK_SCROLL_UP) { + if (zoom == max_zoom) + return TRUE; + + target_x = event->x + ((ltx + rbx) / 2.0 - (gint)(event->x)) / 2; + target_y = event->y + ((lty + rby) / 2.0 - (gint)(event->y)) / 2; + + osm_gps_map_convert_screen_to_geographic(map, target_x, target_y, target); + osm_gps_map_point_get_degrees(target, &target_lat, &target_lon); + osm_gps_map_zoom_in(map); - else if (event->direction == GDK_SCROLL_DOWN) + } else if (event->direction == GDK_SCROLL_DOWN) { + if(zoom == min_zoom) + return TRUE; + + target_x = event->x + ((ltx + rbx) / 2.0 - (gint)(event->x)) * 2; + target_y = event->y + ((lty + rby) / 2.0 - (gint)(event->y)) * 2; + + osm_gps_map_convert_screen_to_geographic(map, target_x, target_y, target); + osm_gps_map_point_get_degrees(target, &target_lat, &target_lon); + osm_gps_map_zoom_out(map); + } + + /* There is no OSM interface to do this afaik. Hack something together */ + /* set_map_pt_at_xy(map, pt, event->x, event->y); */ + + osm_gps_map_set_center(map, target_lat, target_lon); + /* don't allow the insane default handler to get its hands on this event */ return TRUE; } |