webdvd.cpp

   1 // Copyright 2005-6 Ben Hutchings <ben@decadentplace.org.uk>.
   2 // See the file "COPYING" for licence details.
   3
   4 #include <cassert>
   5 #include <cstring>
   6 #include <exception>
   7 #include <fstream>
   8 #include <iomanip>
   9 #include <iostream>
  10 #include <memory>
  11 #include <queue>
  12 #include <set>
  13 #include <sstream>
  14 #include <string>
  15
  16 #include <stdlib.h>
  17
  18 #include <boost/shared_ptr.hpp>
  19
  20 #include <gdkmm/pixbuf.h>
  21 #include <glibmm/convert.h>
  22 #include <glibmm/spawn.h>
  23 #include <gtkmm/main.h>
  24 #include <gtkmm/window.h>
  25
  26 #include <imglib2/ImageErrors.h>
  27 #include <nsGUIEvent.h>
  28 #include <nsIBoxObject.h>
  29 #include <nsIContent.h>
  30 #include <nsIDocShell.h>
  31 #include <nsIDOMAbstractView.h>
  32 #include <nsIDOMBarProp.h>
  33 #include <nsIDOMDocumentEvent.h>
  34 #include <nsIDOMDocumentView.h>
  35 #include <nsIDOMElement.h>
  36 #include <nsIDOMEventTarget.h>
  37 #include <nsIDOMHTMLDocument.h>
  38 #include <nsIDOMMouseEvent.h>
  39 #include <nsIDOMNSDocument.h>
  40 #include <nsIDOMWindow.h>
  41 #include <nsIEventStateManager.h>
  42 #include <nsIInterfaceRequestorUtils.h>
  43 #include <nsIURI.h> // required before nsILink.h
  44 #include <nsILink.h>
  45 #include <nsIPrefBranch.h>
  46 #include <nsIPrefService.h>
  47 #include <nsIPresContext.h>
  48 #include <nsIPresShell.h>
  49 #include <nsIServiceManagerUtils.h>
  50 #include <nsIWebBrowser.h>
  51 #include <nsString.h>
  52
  53 #include "browser_widget.hpp"
  54 #include "child_iterator.hpp"
  55 #include "dvd.hpp"
  56 #include "generate_dvd.hpp"
  57 #include "link_iterator.hpp"
  58 #include "null_prompt_service.hpp"
  59 #include "pixbufs.hpp"
  60 #include "style_sheets.hpp"
  61 #include "temp_file.hpp"
  62 #include "video.hpp"
  63 #include "x_frame_buffer.hpp"
  64 #include "xml_utils.hpp"
  65 #include "xpcom_support.hpp"
  66
  67 using xpcom_support::check;
  68
  69 namespace
  70 {
  71     struct rectangle
  72     {
  73         int left, top;     // inclusive
  74         int right, bottom; // exclusive
  75
  76         rectangle operator|=(const rectangle & other)
  77             {
  78                 if (other.empty())
  79                 {
  80                     // use current extents unchanged
  81                 }
  82                 else if (empty())
  83                 {
  84                     // use other extents
  85                     *this = other;
  86                 }
  87                 else
  88                 {
  89                     // find rectangle enclosing both extents
  90                     left = std::min(left, other.left);
  91                     top = std::min(top, other.top);
  92                     right = std::max(right, other.right);
  93                     bottom = std::max(bottom, other.bottom);
  94                 }
  95
  96                 return *this;
  97             }
  98
  99         rectangle operator&=(const rectangle & other)
 100             {
 101                 // find rectangle enclosed in both extents
 102                 left = std::max(left, other.left);
 103                 top = std::max(top, other.top);
 104                 right = std::max(left, std::min(right, other.right));
 105                 bottom = std::max(top, std::min(bottom, other.bottom));
 106                 return *this;
 107             }
 108
 109         bool empty() const
 110             {
 111                 return left == right || bottom == top;
 112             }
 113     };
 114
 115     rectangle get_elem_rect(nsIDOMNSDocument * ns_doc,
 116                             nsIDOMElement * elem)
 117     {
 118         rectangle result;
 119
 120         // Start with this element's bounding box
 121         nsCOMPtr<nsIBoxObject> box;
 122         check(ns_doc->GetBoxObjectFor(elem, getter_AddRefs(box)));
 123         int width, height;
 124         check(box->GetScreenX(&result.left));
 125         check(box->GetScreenY(&result.top));
 126         check(box->GetWidth(&width));
 127         check(box->GetHeight(&height));
 128         result.right = result.left + width;
 129         result.bottom = result.top + height;
 130
 131         // Merge bounding boxes of all child elements
 132         for (child_iterator it = child_iterator(elem), end; it != end; ++it)
 133         {
 134             nsCOMPtr<nsIDOMNode> child_node(*it);
 135             PRUint16 child_type;
 136             if (check(child_node->GetNodeType(&child_type)),
 137                 child_type == nsIDOMNode::ELEMENT_NODE)
 138             {
 139                 nsCOMPtr<nsIDOMElement> child_elem(
 140                     do_QueryInterface(child_node));
 141                 result |= get_elem_rect(ns_doc, child_elem);
 142             }
 143         }
 144
 145         return result;
 146     }
 147
 148
 149     class webdvd_window : public Gtk::Window
 150     {
 151     public:
 152         webdvd_window(
 153             const video::frame_params & frame_params,
 154             const std::string & main_page_uri,
 155             const std::string & output_dir);
 156
 157         bool is_finished() const;
 158
 159     private:
 160         dvd_contents::pgc_ref add_menu(const std::string & uri);
 161         dvd_contents::pgc_ref add_title(const std::string & uri);
 162         void load_next_page();
 163         void on_net_state_change(const char * uri, gint flags, guint status);
 164         bool browser_is_busy() const
 165             {
 166                 return pending_window_update_ || pending_req_count_;
 167             }
 168         bool process_page();
 169         void save_screenshot();
 170         void process_links(nsIPresShell * pres_shell,
 171                            nsIPresContext * pres_context,
 172                            nsIDOMWindow * dom_window);
 173
 174         video::frame_params frame_params_;
 175         std::string output_dir_;
 176         browser_widget browser_widget_;
 177         nsCOMPtr<nsIStyleSheet> stylesheet_;
 178
 179         dvd_contents contents_;
 180         typedef std::map<std::string, dvd_contents::pgc_ref> resource_map_type;
 181         resource_map_type resource_map_;
 182
 183         std::queue<std::string> page_queue_;
 184         bool pending_window_update_;
 185         int pending_req_count_;
 186         bool have_tweaked_page_;
 187         std::auto_ptr<temp_file> background_temp_;
 188         struct page_state;
 189         std::auto_ptr<page_state> page_state_;
 190
 191         bool finished_;
 192     };
 193
 194     webdvd_window::webdvd_window(
 195         const video::frame_params & frame_params,
 196         const std::string & main_page_uri,
 197         const std::string & output_dir)
 198             : frame_params_(frame_params),
 199               output_dir_(output_dir),
 200               stylesheet_(load_css("file://" WEBDVD_LIB_DIR "/webdvd.css")),
 201               pending_window_update_(false),
 202               pending_req_count_(0),
 203               have_tweaked_page_(false),
 204               finished_(false)
 205     {
 206         set_size_request(frame_params_.width, frame_params_.height);
 207         set_resizable(false);
 208
 209         add(browser_widget_);
 210         browser_widget_.show();
 211         browser_widget_.signal_net_state().connect(
 212             SigC::slot(*this, &webdvd_window::on_net_state_change));
 213
 214         add_menu(main_page_uri);
 215         load_next_page();
 216     }
 217
 218     bool webdvd_window::is_finished() const
 219     {
 220         return finished_;
 221     }
 222
 223     dvd_contents::pgc_ref webdvd_window::add_menu(const std::string & uri)
 224     {
 225         dvd_contents::pgc_ref next_menu(dvd_contents::menu_pgc,
 226                                         contents_.menus.size());
 227         std::pair<resource_map_type::iterator, bool> insert_result(
 228             resource_map_.insert(std::make_pair(uri, next_menu)));
 229
 230         if (!insert_result.second)
 231         {
 232             return insert_result.first->second;
 233         }
 234         else
 235         {
 236             page_queue_.push(uri);
 237             contents_.menus.resize(contents_.menus.size() + 1);
 238             return next_menu;
 239         }
 240     }
 241
 242     dvd_contents::pgc_ref webdvd_window::add_title(const std::string & uri)
 243     {
 244         dvd_contents::pgc_ref next_title(dvd_contents::title_pgc,
 245                                          contents_.titles.size());
 246         std::pair<resource_map_type::iterator, bool> insert_result(
 247             resource_map_.insert(std::make_pair(uri, next_title)));
 248
 249         if (!insert_result.second)
 250         {
 251             return insert_result.first->second;
 252         }
 253         else
 254         {
 255             Glib::ustring hostname;
 256             std::string path(Glib::filename_from_uri(uri, hostname));
 257             // FIXME: Should check the hostname
 258
 259             vob_list list;
 260
 261             // Store a reference to a linked VOB file, or the contents
 262             // of a linked VOB list file.
 263             if (path.compare(path.size() - 4, 4, ".vob") == 0)
 264             {
 265                 if (!Glib::file_test(path, Glib::FILE_TEST_IS_REGULAR))
 266                     throw std::runtime_error(
 267                         path + " is missing or not a regular file");
 268                 vob_ref ref;
 269                 ref.file = path;
 270                 list.push_back(ref);
 271             }
 272             else
 273             {
 274                 assert(path.compare(path.size() - 8, 8, ".voblist") == 0);
 275                 read_vob_list(path).swap(list);
 276             }
 277
 278             contents_.titles.resize(contents_.titles.size() + 1);
 279             contents_.titles.back().swap(list);
 280             return next_title;
 281         }
 282     }
 283
 284     void webdvd_window::load_next_page()
 285     {
 286         assert(!page_queue_.empty());
 287         const std::string & uri = page_queue_.front();
 288         std::cout << "loading " << uri << std::endl;
 289
 290         browser_widget_.load_uri(uri);
 291     }
 292
 293     void webdvd_window::on_net_state_change(const char * uri,
 294                                            gint flags, guint status)
 295     {
 296 #       ifdef DEBUG_ON_NET_STATE_CHANGE
 297         std::cout << "webdvd_window::on_net_state_change(";
 298         if (uri)
 299             std::cout << '"' << uri << '"';
 300         else
 301             std::cout << "NULL";
 302         std::cout << ", ";
 303         {
 304             gint flags_left = flags;
 305             static const struct {
 306                 gint value;
 307                 const char * name;
 308             } flag_names[] = {
 309                 { GTK_MOZ_EMBED_FLAG_START, "STATE_START" },
 310                 { GTK_MOZ_EMBED_FLAG_REDIRECTING, "STATE_REDIRECTING" },
 311                 { GTK_MOZ_EMBED_FLAG_TRANSFERRING, "STATE_TRANSFERRING" },
 312                 { GTK_MOZ_EMBED_FLAG_NEGOTIATING, "STATE_NEGOTIATING" },
 313                 { GTK_MOZ_EMBED_FLAG_STOP, "STATE_STOP" },
 314                 { GTK_MOZ_EMBED_FLAG_IS_REQUEST, "STATE_IS_REQUEST" },
 315                 { GTK_MOZ_EMBED_FLAG_IS_DOCUMENT, "STATE_IS_DOCUMENT" },
 316                 { GTK_MOZ_EMBED_FLAG_IS_NETWORK, "STATE_IS_NETWORK" },
 317                 { GTK_MOZ_EMBED_FLAG_IS_WINDOW, "STATE_IS_WINDOW" }
 318             };
 319             for (int i = 0; i != sizeof(flag_names)/sizeof(flag_names[0]); ++i)
 320             {
 321                 if (flags & flag_names[i].value)
 322                 {
 323                     std::cout << flag_names[i].name;
 324                     flags_left -= flag_names[i].value;
 325                     if (flags_left)
 326                         std::cout << " | ";
 327                 }
 328             }
 329             if (flags_left)
 330                 std::cout << "0x" << std::setbase(16) << flags_left;
 331         }
 332         std::cout << ", " << "0x" << std::setbase(16) << status << ")\n";
 333 #       endif // DEBUG_ON_NET_STATE_CHANGE
 334
 335         if (flags & GTK_MOZ_EMBED_FLAG_IS_REQUEST)
 336         {
 337             if (flags & GTK_MOZ_EMBED_FLAG_START)
 338                 ++pending_req_count_;
 339
 340             if (flags & GTK_MOZ_EMBED_FLAG_STOP)
 341             {
 342                 assert(pending_req_count_ != 0);
 343                 --pending_req_count_;
 344             }
 345         }
 346
 347         if (flags & GTK_MOZ_EMBED_FLAG_IS_DOCUMENT
 348             && flags & GTK_MOZ_EMBED_FLAG_START)
 349         {
 350             pending_window_update_ = true;
 351             have_tweaked_page_ = false;
 352         }
 353
 354         if (flags & GTK_MOZ_EMBED_FLAG_IS_WINDOW
 355             && flags & GTK_MOZ_EMBED_FLAG_STOP)
 356         {
 357             // Check whether the load was successful, ignoring this
 358             // pseudo-error.
 359             if (status != NS_IMAGELIB_ERROR_LOAD_ABORTED)
 360                 check(status);
 361
 362             pending_window_update_ = false;
 363         }
 364
 365         if (!browser_is_busy())
 366         {
 367             try
 368             {
 369                 if (!process_page())
 370                 {
 371                     finished_ = true;
 372                     Gtk::Main::quit();
 373                 }
 374             }
 375             catch (std::exception & e)
 376             {
 377                 std::cerr << "Fatal error";
 378                 if (!page_queue_.empty())
 379                     std::cerr << " while processing <" << page_queue_.front()
 380                               << ">";
 381                 std::cerr << ": " << e.what() << "\n";
 382                 Gtk::Main::quit();
 383             }
 384             catch (Glib::Exception & e)
 385             {
 386                 std::cerr << "Fatal error";
 387                 if (!page_queue_.empty())
 388                     std::cerr << " while processing <" << page_queue_.front()
 389                               << ">";
 390                 std::cerr << ": " << e.what() << "\n";
 391                 Gtk::Main::quit();
 392             }
 393         }
 394     }
 395
 396     bool webdvd_window::process_page()
 397     {
 398         assert(!page_queue_.empty());
 399
 400         nsCOMPtr<nsIWebBrowser> browser(browser_widget_.get_browser());
 401         nsCOMPtr<nsIDocShell> doc_shell(do_GetInterface(browser));
 402         assert(doc_shell);
 403         nsCOMPtr<nsIPresShell> pres_shell;
 404         check(doc_shell->GetPresShell(getter_AddRefs(pres_shell)));
 405         nsCOMPtr<nsIPresContext> pres_context;
 406         check(doc_shell->GetPresContext(getter_AddRefs(pres_context)));
 407         nsCOMPtr<nsIDOMWindow> dom_window;
 408         check(browser->GetContentDOMWindow(getter_AddRefs(dom_window)));
 409
 410         // If we haven't done so already, apply the stylesheet and
 411         // disable scrollbars.
 412         if (!have_tweaked_page_)
 413         {
 414             apply_style_sheet(stylesheet_, pres_shell);
 415
 416             // This actually only needs to be done once.
 417             nsCOMPtr<nsIDOMBarProp> dom_bar_prop;
 418             check(dom_window->GetScrollbars(getter_AddRefs(dom_bar_prop)));
 419             check(dom_bar_prop->SetVisible(false));
 420
 421             have_tweaked_page_ = true;
 422
 423             // Might need to wait a while for things to load or more
 424             // likely for a re-layout.
 425             if (browser_is_busy())
 426                 return true;
 427         }
 428
 429         // All further work should only be done if we're not in preview mode.
 430         if (!output_dir_.empty())
 431         {
 432             // If we haven't already started work on this menu, save a
 433             // screenshot of its normal appearance.
 434             if (!page_state_.get())
 435                 save_screenshot();
 436
 437             // Start or continue processing links.
 438             process_links(pres_shell, pres_context, dom_window);
 439
 440             // If we've finished work on the links, move on to the
 441             // next page, if any, or else generate the DVD filesystem.
 442             if (!page_state_.get())
 443             {
 444                 page_queue_.pop();
 445                 if (page_queue_.empty())
 446                 {
 447                     generate_dvd(contents_, output_dir_);
 448                     return false;
 449                 }
 450                 else
 451                 {
 452                     load_next_page();
 453                 }
 454             }
 455         }
 456
 457         return true;
 458     }
 459
 460     void webdvd_window::save_screenshot()
 461     {
 462         Glib::RefPtr<Gdk::Window> window(get_window());
 463         assert(window);
 464         window->process_updates(true);
 465
 466         background_temp_.reset(new temp_file("webdvd-back-"));
 467         background_temp_->close();
 468         std::cout << "saving " << background_temp_->get_name() << std::endl;
 469         Gdk::Pixbuf::create(Glib::RefPtr<Gdk::Drawable>(window),
 470                             window->get_colormap(),
 471                             0, 0, 0, 0,
 472                             frame_params_.width, frame_params_.height)
 473             ->save(background_temp_->get_name(), "png");
 474     }
 475
 476     struct webdvd_window::page_state
 477     {
 478         page_state(nsIDOMDocument * doc, int width, int height)
 479                 : diff_pixbuf(Gdk::Pixbuf::create(
 480                                   Gdk::COLORSPACE_RGB,
 481                                   true, 8, // has_alpha, bits_per_sample
 482                                   width, height)),
 483                   spumux_temp("webdvd-spumux-"),
 484                   links_temp("webdvd-links-"),
 485                   link_num(0),
 486                   links_it(doc),
 487                   link_changing(false)
 488             {
 489                 spumux_temp.close();
 490                 links_temp.close();
 491             }
 492
 493         Glib::RefPtr<Gdk::Pixbuf> diff_pixbuf;
 494
 495         temp_file spumux_temp;
 496         std::ofstream spumux_file;
 497
 498         temp_file links_temp;
 499
 500         unsigned link_num;
 501         link_iterator links_it, links_end;
 502
 503         rectangle link_rect;
 504         bool link_changing;
 505         Glib::RefPtr<Gdk::Pixbuf> norm_pixbuf;
 506     };
 507
 508     void webdvd_window::process_links(nsIPresShell * pres_shell,
 509                                      nsIPresContext * pres_context,
 510                                      nsIDOMWindow * dom_window)
 511     {
 512         Glib::RefPtr<Gdk::Window> window(get_window());
 513         assert(window);
 514
 515         nsCOMPtr<nsIDOMDocument> basic_doc;
 516         check(dom_window->GetDocument(getter_AddRefs(basic_doc)));
 517         nsCOMPtr<nsIDOMNSDocument> ns_doc(do_QueryInterface(basic_doc));
 518         assert(ns_doc);
 519         nsCOMPtr<nsIEventStateManager> event_state_man(
 520             pres_context->EventStateManager()); // does not AddRef
 521         assert(event_state_man);
 522         nsCOMPtr<nsIDOMDocumentEvent> event_factory(
 523             do_QueryInterface(basic_doc));
 524         assert(event_factory);
 525         nsCOMPtr<nsIDOMDocumentView> doc_view(do_QueryInterface(basic_doc));
 526         assert(doc_view);
 527         nsCOMPtr<nsIDOMAbstractView> view;
 528         check(doc_view->GetDefaultView(getter_AddRefs(view)));
 529
 530         // Set up or recover our iteration state.
 531         std::auto_ptr<page_state> state(page_state_);
 532         if (!state.get())
 533         {
 534             state.reset(
 535                 new page_state(
 536                     basic_doc, frame_params_.width, frame_params_.height));
 537
 538             state->spumux_file.open(state->spumux_temp.get_name().c_str());
 539             state->spumux_file <<
 540                 "<subpictures>\n"
 541                 "  <stream>\n"
 542                 "    <spu force='yes' start='00:00:00.00'\n"
 543                 "        highlight='" << state->links_temp.get_name() << "'\n"
 544                 "        select='" << state->links_temp.get_name() << "'>\n";
 545         }
 546
 547         rectangle window_rect = {
 548             0, 0, frame_params_.width, frame_params_.height
 549         };
 550
 551         unsigned menu_num = resource_map_[page_queue_.front()].index;
 552
 553         for (/* no initialisation */;
 554              state->links_it != state->links_end;
 555              ++state->links_it)
 556         {
 557             nsCOMPtr<nsIDOMNode> node(*state->links_it);
 558
 559             // Find the link URI and separate any fragment from it.
 560             nsCOMPtr<nsILink> link(do_QueryInterface(node));
 561             assert(link);
 562             nsCOMPtr<nsIURI> uri_iface;
 563             check(link->GetHrefURI(getter_AddRefs(uri_iface)));
 564             std::string uri_and_fragment, uri, fragment;
 565             {
 566                 nsCString uri_and_fragment_ns;
 567                 check(uri_iface->GetSpec(uri_and_fragment_ns));
 568                 uri_and_fragment.assign(uri_and_fragment_ns.BeginReading(),
 569                                         uri_and_fragment_ns.EndReading());
 570
 571                 std::size_t hash_pos = uri_and_fragment.find('#');
 572                 uri.assign(uri_and_fragment, 0, hash_pos);
 573                 if (hash_pos != std::string::npos)
 574                     fragment.assign(uri_and_fragment,
 575                                     hash_pos + 1, std::string::npos);
 576             }
 577
 578             // Is this a new link?
 579             if (!state->link_changing)
 580             {
 581                 // Find a rectangle enclosing the link and clip it to the
 582                 // window.
 583                 nsCOMPtr<nsIDOMElement> elem(do_QueryInterface(node));
 584                 assert(elem);
 585                 state->link_rect = get_elem_rect(ns_doc, elem);
 586                 state->link_rect &= window_rect;
 587
 588                 if (state->link_rect.empty())
 589                 {
 590                     std::cerr << "Ignoring invisible link to "
 591                               << uri_and_fragment << "\n";
 592                     continue;
 593                 }
 594
 595                 ++state->link_num;
 596
 597                 if (state->link_num >= unsigned(dvd::menu_buttons_max))
 598                 {
 599                     if (state->link_num == unsigned(dvd::menu_buttons_max))
 600                         std::cerr << "No more than " << dvd::menu_buttons_max
 601                                   << " buttons can be placed on a menu\n";
 602                     std::cerr << "Ignoring link to " << uri_and_fragment
 603                               << "\n";
 604                     continue;
 605                 }
 606
 607                 state->spumux_file <<
 608                     "      <button x0='" << state->link_rect.left << "'"
 609                     " y0='" << state->link_rect.top << "'"
 610                     " x1='" << state->link_rect.right - 1 << "'"
 611                     " y1='" << state->link_rect.bottom - 1 << "'/>\n";
 612
 613                 // Check whether this is a link to a video or a page then
 614                 // add it to the known resources if not already seen; then
 615                 // add it to the menu entries.
 616                 dvd_contents::pgc_ref target;
 617                 // FIXME: This is a bit of a hack.  Perhaps we could decide
 618                 // later based on the MIME type determined by Mozilla?
 619                 if ((uri.size() > 4
 620                      && uri.compare(uri.size() - 4, 4, ".vob") == 0)
 621                     || (uri.size() > 8
 622                         && uri.compare(uri.size() - 8, 8, ".voblist") == 0))
 623                 {
 624                     PRBool is_file;
 625                     check(uri_iface->SchemeIs("file", &is_file));
 626                     if (!is_file)
 627                     {
 628                         std::cerr << "Links to video must use the file:"
 629                                   << " scheme\n";
 630                         continue;
 631                     }
 632                     target = add_title(uri);
 633                     target.sub_index =
 634                         std::strtoul(fragment.c_str(), NULL, 10);
 635                 }
 636                 else
 637                 {
 638                     target = add_menu(uri);
 639                     // TODO: If there's a fragment, work out which button
 640                     // is closest and set target.sub_index.
 641                 }
 642                 contents_.menus[menu_num].entries.push_back(target);
 643
 644                 nsCOMPtr<nsIContent> content(do_QueryInterface(node));
 645                 assert(content);
 646                 nsCOMPtr<nsIDOMEventTarget> event_target(
 647                     do_QueryInterface(node));
 648                 assert(event_target);
 649
 650                 state->norm_pixbuf = Gdk::Pixbuf::create(
 651                     Glib::RefPtr<Gdk::Drawable>(window),
 652                     window->get_colormap(),
 653                     state->link_rect.left,
 654                     state->link_rect.top,
 655                     0,
 656                     0,
 657                     state->link_rect.right - state->link_rect.left,
 658                     state->link_rect.bottom - state->link_rect.top);
 659
 660                 nsCOMPtr<nsIDOMEvent> event;
 661                 check(event_factory->CreateEvent(
 662                           NS_ConvertASCIItoUTF16("MouseEvents"),
 663                           getter_AddRefs(event)));
 664                 nsCOMPtr<nsIDOMMouseEvent> mouse_event(
 665                     do_QueryInterface(event));
 666                 assert(mouse_event);
 667                 check(mouse_event->InitMouseEvent(
 668                           NS_ConvertASCIItoUTF16("mouseover"),
 669                           true,  // can bubble
 670                           true,  // cancelable
 671                           view,
 672                           0,     // detail: mouse click count
 673                           state->link_rect.left, // screenX
 674                           state->link_rect.top,  // screenY
 675                           state->link_rect.left, // clientX
 676                           state->link_rect.top,  // clientY
 677                           false, false, false, false, // qualifiers
 678                           0,     // button: left (or primary)
 679                           0));   // related target
 680                 PRBool dummy;
 681                 check(event_target->DispatchEvent(mouse_event,
 682                                                   &dummy));
 683                 check(event_state_man->SetContentState(content,
 684                                                        NS_EVENT_STATE_HOVER));
 685
 686                 pres_shell->FlushPendingNotifications(true);
 687
 688                 // We may have to exit and wait for image loading
 689                 // to complete, at which point we will be called
 690                 // again.
 691                 if (browser_is_busy())
 692                 {
 693                     state->link_changing = true;
 694                     page_state_ = state;
 695                     return;
 696                 }
 697             }
 698
 699             window->process_updates(true);
 700
 701             Glib::RefPtr<Gdk::Pixbuf> changed_pixbuf(
 702                 Gdk::Pixbuf::create(
 703                     Glib::RefPtr<Gdk::Drawable>(window),
 704                     window->get_colormap(),
 705                     state->link_rect.left,
 706                     state->link_rect.top,
 707                     0,
 708                     0,
 709                     state->link_rect.right - state->link_rect.left,
 710                     state->link_rect.bottom - state->link_rect.top));
 711             diff_rgb_pixbufs(
 712                 state->norm_pixbuf,
 713                 changed_pixbuf,
 714                 state->diff_pixbuf,
 715                 state->link_rect.left,
 716                 state->link_rect.top,
 717                 state->link_rect.right - state->link_rect.left,
 718                 state->link_rect.bottom - state->link_rect.top);
 719         }
 720
 721         quantise_rgba_pixbuf(state->diff_pixbuf, dvd::button_n_colours);
 722
 723         std::cout << "saving " << state->links_temp.get_name()
 724                   << std::endl;
 725         state->diff_pixbuf->save(state->links_temp.get_name(), "png");
 726
 727         state->spumux_file <<
 728             "    </spu>\n"
 729             "  </stream>\n"
 730             "</subpictures>\n";
 731
 732         state->spumux_file.close();
 733
 734         // TODO: if (!state->spumux_file) throw ...
 735
 736         {
 737             std::ostringstream command_stream;
 738             command_stream << "pngtopnm "
 739                            << background_temp_->get_name()
 740                            << " | ppmtoy4m -v0 -n1 -F"
 741                            << frame_params_.rate_numer
 742                            << ":" << frame_params_.rate_denom
 743                            << " -A" << frame_params_.pixel_ratio_width
 744                            << ":" << frame_params_.pixel_ratio_height
 745                            << (" -Ip -S420_mpeg2"
 746                                " | mpeg2enc -v0 -f8 -a2 -o/dev/stdout"
 747                                " | mplex -v0 -f8 -o/dev/stdout /dev/stdin"
 748                                " | spumux -v0 -mdvd ")
 749                            << state->spumux_temp.get_name()
 750                            << " > "
 751                            << contents_.menus[menu_num].vob_temp->get_name();
 752             std::string command(command_stream.str());
 753             const char * argv[] = {
 754                 "/bin/sh", "-c", command.c_str(), 0
 755             };
 756             std::cout << "running " << argv[2] << std::endl;
 757             int command_result;
 758             Glib::spawn_sync(".",
 759                              Glib::ArrayHandle<std::string>(
 760                                  argv, sizeof(argv)/sizeof(argv[0]),
 761                                  Glib::OWNERSHIP_NONE),
 762                              Glib::SPAWN_STDOUT_TO_DEV_NULL,
 763                              SigC::Slot0<void>(),
 764                              0, 0,
 765                              &command_result);
 766             if (command_result != 0)
 767                 throw std::runtime_error("spumux pipeline failed");
 768         }
 769     }
 770
 771     const video::frame_params & lookup_frame_params(const char * str)
 772     {
 773         assert(str);
 774         static const struct { const char * str; bool is_ntsc; }
 775         known_strings[] = {
 776             { "NTSC",  true },
 777             { "ntsc",  true },
 778             { "PAL",   false },
 779             { "pal",   false },
 780             // For DVD purposes, SECAM can be treated identically to PAL.
 781             { "SECAM", false },
 782             { "secam", false }
 783         };
 784         for (std::size_t i = 0;
 785              i != sizeof(known_strings)/sizeof(known_strings[0]);
 786              ++i)
 787             if (std::strcmp(str, known_strings[i].str) == 0)
 788                 return known_strings[i].is_ntsc ?
 789                     video::ntsc_params : video::pal_params;
 790         throw std::runtime_error(
 791             std::string("Invalid video standard: ").append(str));
 792     }
 793
 794     void print_usage(std::ostream & stream, const char * command_name)
 795     {
 796         stream << "Usage: " << command_name
 797                << (" [gtk-options] [--video-std std-name]"
 798                    " [--preview] menu-url [output-dir]\n");
 799     }
 800
 801     void set_browser_preferences()
 802     {
 803         nsCOMPtr<nsIPrefService> pref_service;
 804         static const nsCID pref_service_cid = NS_PREFSERVICE_CID;
 805         check(CallGetService<nsIPrefService>(pref_service_cid,
 806                                              getter_AddRefs(pref_service)));
 807         nsCOMPtr<nsIPrefBranch> pref_branch;
 808
 809         // Disable IE-compatibility kluge that causes backgrounds to
 810         // sometimes/usually be missing from snapshots.  This is only
 811         // effective from Mozilla 1.8 onward.
 812 #       if MOZ_VERSION_MAJOR > 1                                 \
 813            || (MOZ_VERSION_MAJOR == 1 && MOZ_VERSION_MINOR >= 8)
 814         check(pref_service->GetDefaultBranch("layout",
 815                                              getter_AddRefs(pref_branch)));
 816         check(pref_branch->SetBoolPref(
 817                   "fire_onload_after_image_background_loads",
 818                   true));
 819 #       endif
 820
 821         // Set display resolution.  With standard-definition video we
 822         // will be fitting ~600 pixels across a screen typically
 823         // ranging from 10 to 25 inches wide, for a resolution of
 824         // 24-60 dpi.  I therefore declare the average horizontal
 825         // resolution to be 40 dpi.  The vertical resolution will be
 826         // slightly higher (PAL/SECAM) or lower (NTSC), but
 827         // unfortunately Mozilla doesn't support non-square pixels
 828         // (and neither do fontconfig or Xft anyway).
 829         check(pref_service->GetDefaultBranch("browser.display",
 830                                              getter_AddRefs(pref_branch)));
 831         check(pref_branch->SetIntPref("screen_resolution", 40));
 832     }
 833
 834 } // namespace
 835
 836 void fatal_error(const std::string & message)
 837 {
 838     std::cerr << "Fatal error: " << message << "\n";
 839     Gtk::Main::quit();
 840 }
 841
 842 int main(int argc, char ** argv)
 843 {
 844     try
 845     {
 846         video::frame_params frame_params = video::pal_params;
 847         bool preview_mode = false;
 848         std::string menu_url;
 849         std::string output_dir;
 850
 851         // Do initial option parsing.  We have to do this before
 852         // letting Gtk parse the arguments since we may need to spawn
 853         // Xvfb first.
 854         int argi = 1;
 855         while (argi != argc)
 856         {
 857             if (std::strcmp(argv[argi], "--") == 0)
 858             {
 859                 break;
 860             }
 861             else if (std::strcmp(argv[argi], "--help") == 0)
 862             {
 863                 print_usage(std::cout, argv[0]);
 864                 return EXIT_SUCCESS;
 865             }
 866             else if (std::strcmp(argv[argi], "--preview") == 0)
 867             {
 868                 preview_mode = true;
 869                 argi += 1;
 870             }
 871             else if (std::strcmp(argv[argi], "--video-std") == 0)
 872             {
 873                 if (argi + 1 == argc)
 874                 {
 875                     std::cerr << "Missing argument to --video-std\n";
 876                     print_usage(std::cerr, argv[0]);
 877                     return EXIT_FAILURE;
 878                 }
 879                 frame_params = lookup_frame_params(argv[argi + 1]);
 880                 argi += 2;
 881             }
 882             else
 883             {
 884                 argi += 1;
 885             }
 886         }
 887
 888         std::auto_ptr<x_frame_buffer> fb;
 889         if (!preview_mode)
 890         {
 891             // Spawn Xvfb and set env variables so that Xlib will use it
 892             // Use 8 bits each for RGB components, which should translate into
 893             // "enough" bits for YUV components.
 894             fb.reset(new x_frame_buffer(frame_params.width,
 895                                         frame_params.height,
 896                                         3 * 8));
 897             setenv("XAUTHORITY", fb->get_authority().c_str(), true);
 898             setenv("DISPLAY", fb->get_display().c_str(), true);
 899         }
 900
 901         // Initialise Gtk
 902         Gtk::Main kit(argc, argv);
 903
 904         // Complete option parsing with Gtk's options out of the way.
 905         argi = 1;
 906         while (argi != argc)
 907         {
 908             if (std::strcmp(argv[argi], "--") == 0)
 909             {
 910                 argi += 1;
 911                 break;
 912             }
 913             else if (std::strcmp(argv[argi], "--preview") == 0)
 914             {
 915                 argi += 1;
 916             }
 917             else if (std::strcmp(argv[argi], "--video-std") == 0)
 918             {
 919                 argi += 2;
 920             }
 921             else if (argv[argi][0] == '-')
 922             {
 923                 std::cerr << "Invalid option: " << argv[argi] << "\n";
 924                 print_usage(std::cerr, argv[0]);
 925                 return EXIT_FAILURE;
 926             }
 927             else
 928             {
 929                 break;
 930             }
 931         }
 932
 933         // Look for a starting URL or filename and (except in preview
 934         // mode) an output directory after the options.
 935         if (argc - argi != (preview_mode ? 1 : 2))
 936         {
 937             print_usage(std::cerr, argv[0]);
 938             return EXIT_FAILURE;
 939         }
 940         if (std::strstr(argv[argi], "://"))
 941         {
 942             // It appears to be an absolute URL, so use it as-is.
 943             menu_url = argv[argi];
 944         }
 945         else
 946         {
 947             // Assume it's a filename.  Resolve it to an absolute URL.
 948             std::string path(argv[argi]);
 949             if (!Glib::path_is_absolute(path))
 950                 path = Glib::build_filename(Glib::get_current_dir(), path);
 951             menu_url = Glib::filename_to_uri(path);
 952         }
 953         if (!preview_mode)
 954             output_dir = argv[argi + 1];
 955
 956         // Initialise Mozilla
 957         browser_widget::initialiser browser_init;
 958         set_browser_preferences();
 959         if (!preview_mode)
 960             null_prompt_service::install();
 961
 962         // Run the browser/converter
 963         webdvd_window window(frame_params, menu_url, output_dir);
 964         Gtk::Main::run(window);
 965
 966         return ((preview_mode || window.is_finished())
 967                 ? EXIT_SUCCESS
 968                 : EXIT_FAILURE);
 969     }
 970     catch (std::exception & e)
 971     {
 972         std::cerr << "Fatal error: " << e.what() << "\n";
 973         return EXIT_FAILURE;
 974     }
 975 }