helpdlg.cpp

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/***********************************************************************
 Freeciv - Copyright (C) 1996 - A Kjeldberg, L Gregersen, P Unold
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.
 
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
***********************************************************************/
 
#ifdef HAVE_CONFIG_H
#include <fc_config.h>
#endif
 
// Qt
#include <QApplication>
#include <QGraphicsDropShadowEffect>
#include <QGroupBox>
#include <QHBoxLayout>
#include <QProgressBar>
#include <QPushButton>
#include <QScreen>
#include <QScrollArea>
#include <QSplitter>
#include <QStack>
#include <QStringList>
#include <QTextBrowser>
#include <QTreeWidget>
#include <QVBoxLayout>
 
// utility
#include "fcintl.h"
 
// common
#include "movement.h"
#include "nation.h"
#include "specialist.h"
#include "terrain.h"
#include "unit.h"
 
// client
#include "helpdata.h"
 
// gui-qt
#include "fc_client.h"
#include "fonts.h"
#include "helpdlg.h"
#include "sprite.h"
 
#define MAX_HELP_TEXT_SIZE 8192
#define REQ_LABEL_NEVER _("(Never)")
#define REQ_LABEL_NONE _("?tech:None")
static help_dialog *help_dlg = nullptr;
static canvas *terrain_canvas(struct terrain *terrain,
                              const struct extra_type *resource = nullptr,
                              enum extra_cause cause = EC_COUNT);
 
/**********************************************************************/
void popup_help_dialog_string(const char *item)
{
  popup_help_dialog_typed(Q_(item), HELP_ANY);
}
 
/**********************************************************************/
void popup_help_dialog_typed(const char *item, enum help_page_type htype)
{
  int pos;
  const help_item *topic;
 
  if (help_dlg == nullptr) {
    help_dlg = new help_dialog();
  } else {
    help_dlg->reactivate();
  }
 
  topic = get_help_item_spec(item, htype, &pos);
  if (pos >= 0) {
    help_dlg->set_topic(topic);
  }
  help_dlg->setVisible(true);
  help_dlg->activateWindow();
}
 
/**********************************************************************/
void popdown_help_dialog(void)
{
  if (help_dlg) {
    help_dlg->setVisible(false);
    help_dlg->deleteLater();
    help_dlg = nullptr;
  }
}
 
/**********************************************************************/
void update_help_fonts()
{
  if (help_dlg) {
    help_dlg->update_fonts();
  }
}
 
/**********************************************************************/
help_dialog::help_dialog(QWidget *parent) : qfc_dialog(parent)
{
  QHBoxLayout *hbox;
  QPushButton *but;
  QTreeWidgetItem *first;
  QVBoxLayout *layout;
  QWidget *buttons;
 
  setWindowTitle(_("Freeciv Help Browser"));
  history_pos = -1;
  update_history = true;
  layout = new QVBoxLayout(this);
 
  splitter = new QSplitter(this);
  layout->addWidget(splitter, 10);
 
  tree_wdg = new QTreeWidget();
  tree_wdg->setHeaderHidden(true);
  make_tree();
  splitter->addWidget(tree_wdg);
 
  help_wdg = new help_widget(splitter);
  connect(
    tree_wdg,
    &QTreeWidget::currentItemChanged,
    this, &help_dialog::item_changed
  );
  help_wdg->layout()->setContentsMargins(0, 0, 0, 0);
  splitter->addWidget(help_wdg);
 
  buttons = new QWidget;
  hbox = new QHBoxLayout;
  prev_butt = new QPushButton(style()->standardIcon(
                              QStyle::QStyle::SP_ArrowLeft), (""));
  connect(prev_butt, &QAbstractButton::clicked, this,
          &help_dialog::history_back);
  hbox->addWidget(prev_butt);
  next_butt = new QPushButton(style()->standardIcon(
                              QStyle::QStyle::SP_ArrowRight), (""));
  connect(next_butt, &QAbstractButton::clicked, this,
          &help_dialog::history_forward);
  hbox->addWidget(next_butt);
  hbox->addStretch(20);
  but = new QPushButton(style()->standardIcon(
                        QStyle::SP_DialogHelpButton), _("About Qt"));
  connect(but, &QPushButton::pressed, &QApplication::aboutQt);
  hbox->addWidget(but, Qt::AlignRight);
  but = new QPushButton(style()->standardIcon(
                        QStyle::SP_DialogDiscardButton), _("Close"));
  connect(but, &QPushButton::pressed, this, &QWidget::close);
  hbox->addWidget(but, Qt::AlignRight);
  buttons->setLayout(hbox);
  layout->addWidget(buttons, 0, Qt::AlignBottom);
 
 
  first = tree_wdg->topLevelItem(0);
  if (first) {
    tree_wdg->setCurrentItem(first);
  }
}
 
/**********************************************************************/
void help_dialog::update_fonts()
{
  help_wdg->update_fonts();
}
 
/**********************************************************************/
void help_dialog::hideEvent(QHideEvent *event)
{
  gui()->qt_settings.help_geometry = saveGeometry();
  gui()->qt_settings.help_splitter1 = splitter->saveState();
}
 
/**********************************************************************/
void help_dialog::showEvent(QShowEvent *event)
{
  QList<int> sizes;
 
  if (!gui()->qt_settings.help_geometry.isNull()) {
    restoreGeometry(gui()->qt_settings.help_geometry);
    splitter->restoreState(gui()->qt_settings.help_splitter1);
  } else {
    QRect rect = QApplication::primaryScreen()->availableGeometry();
 
    resize((rect.width() * 3) / 5, (rect.height() * 3) / 6);
    sizes << rect.width() / 10 << rect.width() / 3;
    splitter->setSizes(sizes);
  }
}
 
/**********************************************************************/
void help_dialog::closeEvent(QCloseEvent *event)
{
  gui()->qt_settings.help_geometry = saveGeometry();
  gui()->qt_settings.help_splitter1 = splitter->saveState();
}
 
/**********************************************************************/
void help_dialog::make_tree()
{
  char *title;
  int dep;
  QHash<int, QTreeWidgetItem *> hash;
  QIcon icon;
  QTreeWidgetItem *item;
  sprite *spite;
  struct advance *padvance;
  struct canvas *pcan;
  struct extra_type *pextra;
  struct government *gov;
  struct impr_type *imp;
  struct nation_type *nation;
  struct terrain *pterrain;
  struct unit_type *f_type;
  struct drawn_sprite sprs[80];
 
  help_items_iterate(pitem) {
    const char *s;
    int last;
    title = pitem->topic;
 
    for (s = pitem->topic; *s == ' '; s++) {
      // Nothing
    }
 
    item = new QTreeWidgetItem(QStringList(title));
    topics_map[item] = pitem;
    dep = s - pitem->topic;
    hash.insert(dep, item);
 
    if (dep == 0) {
      tree_wdg->addTopLevelItem(item);
    } else {
      last = dep - 1;
      spite = nullptr;
 
      switch (pitem->type) {
      case HELP_EXTRA:
        pextra = extra_type_by_translated_name(s);
        fill_basic_extra_sprite_array(tileset, sprs, pextra);
        icon = QIcon(*sprs->sprite->pm);
        break;
 
      case HELP_GOVERNMENT:
        gov = government_by_translated_name(s);
        spite = get_government_sprite(tileset, gov);
        if (spite) {
          icon = QIcon(*spite->pm);
        }
        break;
 
      case HELP_IMPROVEMENT:
      case HELP_WONDER:
        imp = improvement_by_translated_name(s);
        spite = get_building_sprite(tileset, imp);
        if (spite) {
          icon = QIcon(*spite->pm);
        }
        break;
      case HELP_NATIONS:
        nation = nation_by_translated_plural(s);
        spite = get_nation_flag_sprite(tileset, nation);
        if (spite) {
          icon = QIcon(*spite->pm);
        }
        break;
      case HELP_TECH:
        padvance  = advance_by_translated_name(s);
        if (is_regular_advance(padvance)) {
          Tech_type_id i = advance_number(padvance);
 
          spite = get_tech_sprite(tileset, i);
          if (spite) {
            icon = QIcon(*spite->pm);
          }
        }
        break;
 
      case HELP_TERRAIN:
        pterrain = terrain_by_translated_name(s);
        pcan = terrain_canvas(pterrain);
        if (pcan) {
          icon = QIcon(pcan->map_pixmap);
          delete pcan;
        }
        break;
 
      case HELP_UNIT:
        f_type = unit_type_by_translated_name(s);
        if (f_type) {
          spite = get_unittype_sprite(tileset, f_type,
                                      ACTIVITY_LAST, direction8_invalid());
        }
        if (spite) {
          icon = QIcon(*spite->pm);
        }
        break;
 
      default:
        break;
      }
 
      if (!icon.isNull()) {
        item->setIcon(0, icon);
      }
 
      hash.value(last)->addChild(item);
    }
  } help_items_iterate_end;
}
 
/**********************************************************************/
void help_dialog::set_topic(const help_item *topic)
{
  help_wdg->set_topic(topic);
  // Reverse search of the item to select.
  QHash<QTreeWidgetItem *, const help_item *>::const_iterator
      i = topics_map.cbegin();
  for ( ; i != topics_map.cend(); ++i) {
    if (i.value() == topic) {
      tree_wdg->setCurrentItem(i.key());
      break;
    }
  }
}
 
/**********************************************************************/
void help_dialog::history_forward()
{
  QTreeWidgetItem *i;
 
  update_history = false;
  if (history_pos < item_history.count()) {
    history_pos++;
  }
  i = item_history.value(history_pos);
  if (i != nullptr) {
    tree_wdg->setCurrentItem(i);
  }
}
 
/**********************************************************************/
void help_dialog::history_back()
{
  QTreeWidgetItem *i;
 
  update_history = false;
  if (history_pos > 0) {
    history_pos--;
  }
  i = item_history.value(history_pos);
  if (i != nullptr) {
    tree_wdg->setCurrentItem(i);
  }
}
 
/**********************************************************************/
void help_dialog::update_buttons()
{
  if (history_pos == 0) {
    prev_butt->setEnabled(false);
  } else {
    prev_butt->setEnabled(true);
  }
  if (history_pos >= item_history.size() - 1) {
    next_butt->setEnabled(false);
  } else {
    next_butt->setEnabled(true);
  }
}
 
/**********************************************************************/
void help_dialog::item_changed(QTreeWidgetItem *item, QTreeWidgetItem *prev)
{
 
  if (prev == item) {
    return;
  }
 
  help_wdg->set_topic(topics_map[item]);
 
  if (update_history) {
    history_pos++;
    item_history.append(item);
  } else {
    update_history = true;
  }
  update_buttons();
}
 
/**********************************************************************/
help_widget::help_widget(QWidget *parent) :
  QWidget(parent),
  main_widget(nullptr), text_browser(nullptr), bottom_panel(nullptr),
  info_panel(nullptr), splitter(nullptr), info_layout(nullptr)
{
  setup_ui();
}
 
/**********************************************************************/
help_widget::help_widget(const help_item *topic, QWidget *parent) :
  QWidget(parent),
  main_widget(nullptr), text_browser(nullptr), bottom_panel(nullptr),
  info_panel(nullptr), splitter(nullptr), info_layout(nullptr)
{
  setup_ui();
  set_topic(topic);
}
 
/**********************************************************************/
help_widget::~help_widget() {
  // Nothing to do here
}
 
/**********************************************************************/
void help_widget::setup_ui()
{
  QVBoxLayout *layout;
  QHBoxLayout *group_layout;
 
  layout = new QVBoxLayout();
  setLayout(layout);
 
  box_wdg = new QFrame(this);
  layout->addWidget(box_wdg);
  group_layout = new QHBoxLayout(box_wdg);
  box_wdg->setLayout(group_layout);
  box_wdg->setFrameShape(QFrame::StyledPanel);
  box_wdg->setFrameShadow(QFrame::Raised);
 
  title_label = new QLabel(box_wdg);
  title_label->setProperty(fonts::default_font, "true");
  group_layout->addWidget(title_label);
 
  text_browser = new QTextBrowser(this);
  text_browser->setProperty(fonts::help_text, "true");
  layout->addWidget(text_browser);
  main_widget = text_browser;
 
  update_fonts();
  splitter_sizes << 200 << 400;
}
 
/**********************************************************************/
void help_widget::do_layout(bool horizontal)
{
  QWidget *right;
  enum Qt::Orientation main_layout;
  enum Qt::Orientation bottom_layout;
 
  if (horizontal) {
    main_layout = Qt::Horizontal;
    bottom_layout = Qt::Vertical;
  } else {
    main_layout = Qt::Vertical;
    bottom_layout = Qt::Horizontal;
  }
 
  layout()->removeWidget(main_widget);
  main_widget->setParent(nullptr);
 
  if (bottom_panel) {
    splitter = new QSplitter(bottom_layout);
    splitter->addWidget(text_browser);
    splitter->setStretchFactor(0, 100);
    splitter->addWidget(bottom_panel);
    splitter->setStretchFactor(1, 0);
    right = splitter;
  } else {
    right = text_browser;
  }
 
  if (info_panel) {
    splitter = new QSplitter(main_layout);
    splitter->addWidget(info_panel);
    splitter->setStretchFactor(0, 25);
    splitter->addWidget(right);
    splitter->setStretchFactor(1, 75);
    splitter->setSizes(splitter_sizes);
    main_widget = splitter;
    info_panel->setLayout(info_layout);
  } else {
    main_widget = right;
  }
 
  layout()->addWidget(main_widget);
  qobject_cast<QVBoxLayout *>(layout())->setStretchFactor(main_widget, 100);
}
 
/**********************************************************************/
void help_widget::update_fonts()
{
  QList<QWidget *> l;
  QFont *f;
 
  l = findChildren<QWidget *>();
 
  f = fc_font::instance()->get_font(fonts::notify_label);
  for (int i = 0; i < l.size(); ++i) {
    if (l.at(i)->property(fonts::help_label).isValid()) {
      l.at(i)->setFont(*f);
    }
  }
  f = fc_font::instance()->get_font(fonts::help_text);
  for (int i = 0; i < l.size(); ++i) {
    if (l.at(i)->property(fonts::help_text).isValid()) {
      l.at(i)->setFont(*f);
    }
  }
  f = fc_font::instance()->get_font(fonts::default_font);
  for (int i = 0; i < l.size(); ++i) {
    if (l.at(i)->property(fonts::default_font).isValid()) {
      l.at(i)->setFont(*f);
    }
  }
}
 
/**********************************************************************/
void help_widget::undo_layout()
{
  // Save the splitter sizes to avoid jumps
  if (info_panel) {
    splitter_sizes = splitter->sizes();
  }
  // Unparent the widget we want to keep
  text_browser->setParent(nullptr);
  // Delete everything else
  if (text_browser != main_widget) {
    main_widget->deleteLater();
  }
  // Reset pointers to defaults
  main_widget = text_browser;
  bottom_panel = nullptr;
  info_panel = nullptr;
  splitter = nullptr;
  info_layout = nullptr;
}
 
/**********************************************************************/
void help_widget::show_info_panel()
{
  info_panel = new QWidget();
  info_layout = new QVBoxLayout();
}
 
/**********************************************************************/
void help_widget::add_info_pixmap(QPixmap *pm, bool shadow)
{
  QLabel *label = new QLabel();
  QGraphicsDropShadowEffect *effect;
 
  label->setAlignment(Qt::AlignHCenter);
  label->setPixmap(*pm);
 
  if (shadow) {
    effect = new QGraphicsDropShadowEffect(label);
    effect->setBlurRadius(3);
    effect->setOffset(0, 2);
    label->setGraphicsEffect(effect);
  }
 
  info_layout->addWidget(label);
}
 
/**********************************************************************/
void help_widget::add_info_label(const QString &text)
{
  QLabel *label = new QLabel(text);
  label->setWordWrap(true);
  label->setTextFormat(Qt::RichText);
  label->setProperty(fonts::help_label, "true");
  info_layout->addWidget(label);
}
 
/**********************************************************************/
void help_widget::add_info_progress(const QString &text, int progress,
                                    int min, int max, const QString &value)
{
  QGridLayout *layout;
  QLabel *label;
  QProgressBar *bar;
  QWidget *wdg;
 
  wdg = new QWidget();
  layout = new QGridLayout(wdg);
  layout->setContentsMargins(0, 0, 0, 0);
  layout->setVerticalSpacing(0);
 
  label = new QLabel(text, wdg);
  layout->addWidget(label, 0, 0);
  label->setProperty(fonts::help_label, "true");
  label = new QLabel(wdg);
  if (value.isEmpty()) {
    label->setNum(progress);
  } else {
    label->setText(value);
  }
  label->setProperty(fonts::help_label, "true");
  layout->addWidget(label, 0, 1, Qt::AlignRight);
 
  bar = new QProgressBar(wdg);
  bar->setMaximumHeight(4);
  bar->setRange(min, max != min ? max : min + 1);
  bar->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Fixed);
  bar->setTextVisible(false);
  bar->setValue(progress);
  layout->addWidget(bar, 1, 0, 1, 2);
 
  info_layout->addWidget(wdg);
}
 
/**********************************************************************/
void help_widget::add_extras_of_act_for_terrain(struct terrain *pterr,
                                                enum unit_activity act,
                                                const char *label)
{
  struct universal for_terr;
  enum extra_cause cause = activity_to_extra_cause(act);
 
  for_terr.kind = VUT_TERRAIN;
  for_terr.value.terrain = pterr;
 
  extra_type_by_cause_iterate(cause, pextra) {
    if (pextra->buildable
        && universal_fulfills_requirements(FALSE, &(pextra->reqs),
                                           &for_terr)) {
      QLabel *tb;
      QString str;
 
      tb = new QLabel(this);
      tb->setProperty(fonts::help_label, "true");
      tb->setTextInteractionFlags(Qt::LinksAccessibleByMouse);
      tb->setTextFormat(Qt::RichText);
 
      str = str + QString(label)
            + link_me(extra_name_translation(pextra), HELP_EXTRA)
            + QString(helptext_extra_for_terrain_str(pextra, pterr, act))
              .toHtmlEscaped()
            + "\n";
      tb->setText(str.trimmed());
      connect(tb, &QLabel::linkActivated,
              this, &help_widget::anchor_clicked);
      info_layout->addWidget(tb);
    }
  } extra_type_by_cause_iterate_end;
}
 
/**********************************************************************/
QString help_widget::link_me(const char *str, help_page_type hpt)
{
  QString s;
  s = QString(str).toHtmlEscaped().replace(" ", "&nbsp;");
  return " <a href=" + QString::number(hpt)
            + "," + s + ">" + s + "</a> ";
}
 
/**********************************************************************/
void help_widget::add_info_separator()
{
  info_layout->addSpacing(2 * info_layout->spacing());
}
 
/**********************************************************************/
void help_widget::info_panel_done()
{
  info_layout->addStretch();
}
 
/**********************************************************************/
void help_widget::anchor_clicked(const QString &link)
{
  QStringList sl;
  int n;
  QString st;
  enum help_page_type type;
 
  sl = link.split(",");
  n = sl.at(0).toInt();
  type = static_cast<help_page_type>(n);
  st = sl.at(1);
  st = st.replace("\u00A0", " ");
 
  if (strcmp(qPrintable(st), REQ_LABEL_NEVER) != 0
      && strcmp(qPrintable(st),
                skip_intl_qualifier_prefix(REQ_LABEL_NONE)) != 0
      && strcmp(qPrintable(st),
                advance_name_translation(advance_by_number(A_NONE))) != 0) {
    popup_help_dialog_typed(qPrintable(st), type);
  }
}
 
/**********************************************************************/
void help_widget::set_topic(const help_item *topic)
{
  char *title = topic->topic;
  bool orient = true;
 
  for ( ; *title == ' '; ++title) {
    // Do nothing
  }
  title_label->setTextFormat(Qt::PlainText);
  title_label->setText(title);
 
  undo_layout();
 
  switch (topic->type) {
    case HELP_ANY:
    case HELP_COUNTER:
    case HELP_MULTIPLIER:
    case HELP_RULESET:
    case HELP_TILESET:
    case HELP_MUSICSET:
    case HELP_TEXT:
      set_topic_other(topic, title);
      break;
    case HELP_EXTRA:
      orient = set_topic_extra(topic, title);
      break;
    case HELP_GOODS:
      set_topic_goods(topic, title);
      break;
    case HELP_GOVERNMENT:
      set_topic_government(topic, title);
      break;
    case HELP_IMPROVEMENT:
    case HELP_WONDER:
      set_topic_building(topic, title);
      break;
    case HELP_NATIONS:
      set_topic_nation(topic, title);
      break;
    case HELP_SPECIALIST:
      set_topic_specialist(topic, title);
      break;
    case HELP_TECH:
      set_topic_tech(topic, title);
      break;
    case HELP_TERRAIN:
      set_topic_terrain(topic, title);
      break;
    case HELP_UNIT:
      set_topic_unit(topic, title);
      break;
    case HELP_LAST: // Just to avoid warning
      break;
  }
 
  do_layout(orient);
}
 
/**********************************************************************/
void help_widget::set_bottom_panel(QWidget *widget) {
  bottom_panel = widget;
}
 
/**********************************************************************/
void help_widget::set_topic_other(const help_item *topic,
                                    const char *title)
{
  if (topic->text) {
    text_browser->setPlainText(topic->text);
  } else {
    text_browser->setPlainText(""); // Something better to do ?
  }
}
 
/**********************************************************************/
void help_widget::set_topic_unit(const help_item *topic,
                                   const char *title)
{
  char buffer[MAX_HELP_TEXT_SIZE];
  int upkeep, max_upkeep;
  struct advance *tech;
  struct canvas *canvas;
  const struct unit_type *obsolete;
  struct unit_type *utype, *max_utype;
  QList<int> list;
  QString str;
 
  utype = unit_type_by_translated_name(title);
  if (utype) {
    helptext_unit(buffer, sizeof(buffer), client.conn.playing,
                  topic->text, utype, TRUE);
    text_browser->setPlainText(buffer);
 
    // Create information panel
    show_info_panel();
    max_utype = uclass_max_values(utype->uclass);
 
    // Unit icon
    canvas = qtg_canvas_create(
               tileset_full_tile_width(tileset),
               tileset_full_tile_height(tileset)
             );
    canvas->map_pixmap.fill(Qt::transparent);
    put_unittype(utype, canvas, 1.0f, 0, 0);
    add_info_pixmap(&canvas->map_pixmap);
    qtg_canvas_free(canvas);
 
    add_info_progress(_("Attack:"), utype->attack_strength, 0,
                      max_utype->attack_strength);
    add_info_progress(_("Defense:"), utype->defense_strength,
                      0, max_utype->defense_strength);
    add_info_progress(_("Moves:"), utype->move_rate, 0, max_utype->move_rate,
                      move_points_text(utype->move_rate, true));
 
    add_info_separator();
 
    add_info_progress(_("Hitpoints:"), utype->hp, 0, max_utype->hp);
    add_info_progress(_("Cost:"), utype_build_shield_cost_base(utype),
                      0, utype_build_shield_cost_base(max_utype));
    add_info_progress(_("Firepower:"), utype->firepower, 0,
                      max_utype->firepower);
 
    // Upkeep
    upkeep = utype->upkeep[O_FOOD] + utype->upkeep[O_GOLD]
             + utype->upkeep[O_LUXURY] + utype->upkeep[O_SCIENCE]
             + utype->upkeep[O_SHIELD] + utype->upkeep[O_TRADE]
             + utype->happy_cost;
    max_upkeep = max_utype->upkeep[O_FOOD] + max_utype->upkeep[O_GOLD]
                 + max_utype->upkeep[O_LUXURY] + max_utype->upkeep[O_SCIENCE]
                 + max_utype->upkeep[O_SHIELD] + max_utype->upkeep[O_TRADE]
                 + max_utype->happy_cost;
    add_info_progress(_("Basic upkeep:"), upkeep, 0, max_upkeep,
                      helptext_unit_upkeep_str(utype));
 
    add_info_separator();
 
    // Tech requirement
    tech = utype_primary_tech_req(utype);
    if (advance_number(tech) != A_NONE) {
      QLabel *tb;
 
      tb = new QLabel(this);
      // TRANS: this and similar literal strings interpreted as (Qt) HTML
      str = _("Requires");
      str = "<b>" + str + "</b> "
            + link_me(advance_name_translation(tech), HELP_TECH);
 
      tb->setProperty(fonts::help_label, "true");
      tb->setTextInteractionFlags(Qt::LinksAccessibleByMouse);
      tb->setTextFormat(Qt::RichText);
      tb->setText(str.trimmed());
      connect(tb, &QLabel::linkActivated,
              this, &help_widget::anchor_clicked);
      info_layout->addWidget(tb);
    } else {
      add_info_label(_("No technology required."));
    }
 
    // Obsolescence
    obsolete = utype->obsoleted_by;
    if (obsolete) {
      tech = utype_primary_tech_req(obsolete);
      if (advance_number(tech) != A_NONE) {
        QLabel *tb;
 
        tb = new QLabel(this);
        str = _("Obsoleted by");
        str = "<b>" + str + "</b> "
              + link_me(utype_name_translation(obsolete), HELP_UNIT)
              + "("  + link_me(advance_name_translation(tech), HELP_TECH)
              + ")";
        tb->setProperty(fonts::help_label, "true");
        tb->setTextInteractionFlags(Qt::LinksAccessibleByMouse);
        tb->setTextFormat(Qt::RichText);
        tb->setText(str.trimmed());
        connect(tb, &QLabel::linkActivated,
                this, &help_widget::anchor_clicked);
        info_layout->addWidget(tb);
      } else {
        add_info_label(
          // TRANS: Current unit obsoleted by other unit
          QString(_("Obsoleted by %1."))
          .arg(utype_name_translation(obsolete))
          .toHtmlEscaped());
      }
    } else {
      add_info_label(_("Never obsolete."));
    }
 
    info_panel_done();
 
    delete max_utype;
  } else {
    set_topic_other(topic, title);
  }
}
 
/**********************************************************************/
void help_widget::set_topic_building(const help_item *topic,
                                     const char *title)
{
  char buffer[MAX_HELP_TEXT_SIZE];
  int type, value;
  struct sprite *spr;
  struct impr_type *itype = improvement_by_translated_name(title);
  char req_buf[512];
  QString str, s1, s2;
  QLabel *tb;
 
  if (itype) {
    helptext_building(buffer, sizeof(buffer), client.conn.playing,
                      topic->text, itype);
    text_browser->setPlainText(buffer);
    show_info_panel();
    spr = get_building_sprite(tileset, itype);
    if (spr) {
      add_info_pixmap(spr->pm);
    }
    str = _("Base Cost:");
    str = "<b>" + str + "</b>" + " "
          + QString::number(impr_base_build_shield_cost(itype))
            .toHtmlEscaped();
    add_info_label(str);
    if (!is_great_wonder(itype)) {
      str = _("Upkeep:");
      str = "<b>" + str + "</b>" + " "
            + QString::number(itype->upkeep).toHtmlEscaped();
      add_info_label(str);
    }
 
    requirement_vector_iterate(&itype->reqs, preq) {
      if (!preq->present) {
        continue;
      }
      universal_extraction(&preq->source, &type, &value);
      if (type == VUT_ADVANCE) {
        s1 = link_me(universal_name_translation(&preq->source, req_buf,
                                       sizeof(req_buf)), HELP_TECH);
      } else if (type == VUT_GOVERNMENT) {
        s1 = link_me(universal_name_translation(&preq->source, req_buf,
                                       sizeof(req_buf)), HELP_GOVERNMENT);
      } else if (type == VUT_TERRAIN) {
        s1 = link_me(universal_name_translation(&preq->source, req_buf,
                                       sizeof(req_buf)), HELP_TERRAIN);
      }
      break;
    } requirement_vector_iterate_end;
 
    if (!s1.isEmpty()) {
      tb = new QLabel(this);
      str = _("Requirement:");
      str = "<b>" + str + "</b> " + s1;
      tb->setProperty(fonts::help_label, "true");
      tb->setTextInteractionFlags(Qt::LinksAccessibleByMouse);
      tb->setTextFormat(Qt::RichText);
      tb->setText(str.trimmed());
      connect(tb, &QLabel::linkActivated,
              this, &help_widget::anchor_clicked);
      info_layout->addWidget(tb);
    }
 
    requirement_vector_iterate(&itype->obsolete_by, pobs) {
      if (pobs->source.kind == VUT_ADVANCE) {
        s2 = link_me(advance_name_translation(pobs->source.value.advance),
                     HELP_TECH);
        break;
      }
    } requirement_vector_iterate_end;
 
    str = _("Obsolete by:");
    str = "<b>" + str + "</b> " + s2;
    if (!s2.isEmpty()) {
      tb = new QLabel(this);
      tb->setProperty(fonts::help_label, "true");
      tb->setTextInteractionFlags(Qt::LinksAccessibleByMouse);
      tb->setTextFormat(Qt::RichText);
      tb->setText(str.trimmed());
      connect(tb, &QLabel::linkActivated,
              this, &help_widget::anchor_clicked);
      info_layout->addWidget(tb);
    }
    info_panel_done();
  } else {
    set_topic_other(topic, title);
  }
}
 
/**********************************************************************/
void help_widget::set_topic_tech(const help_item *topic,
                                 const char *title)
{
  char buffer[MAX_HELP_TEXT_SIZE];
  struct sprite *spr;
  QLabel *tb;
  struct advance *padvance = advance_by_translated_name(title);
  QString str;
 
  if (is_regular_advance(padvance)) {
    int n = advance_number(padvance);
 
    show_info_panel();
    spr = get_tech_sprite(tileset, n);
    if (spr) {
      add_info_pixmap(spr->pm);
    }
 
    governments_iterate(pgov) {
      requirement_vector_iterate(&pgov->reqs, preq) {
        if (VUT_ADVANCE == preq->source.kind
            && preq->source.value.advance == padvance) {
          tb = new QLabel(this);
          tb->setProperty(fonts::help_label, "true");
          tb->setTextInteractionFlags(Qt::LinksAccessibleByMouse);
          tb->setTextFormat(Qt::RichText);
          str = _("Allows");
          str = "<b>" + str + "</b> "
            + link_me(government_name_translation(pgov), HELP_GOVERNMENT);
          tb->setText(str.trimmed());
          connect(tb, &QLabel::linkActivated,
                  this, &help_widget::anchor_clicked);
          info_layout->addWidget(tb);
        }
      } requirement_vector_iterate_end;
    } governments_iterate_end;
 
    improvement_iterate(pimprove) {
      if (valid_improvement(pimprove)) {
        requirement_vector_iterate(&pimprove->reqs, preq) {
          if (VUT_ADVANCE == preq->source.kind
              && preq->source.value.advance == padvance) {
            str = _("Allows");
            str = "<b>" + str + "</b> "
              + link_me(improvement_name_translation(pimprove),
                        is_great_wonder(pimprove) ? HELP_WONDER
                        : HELP_IMPROVEMENT);
            tb = new QLabel(this);
            tb->setProperty(fonts::help_label, "true");
            tb->setTextInteractionFlags(Qt::LinksAccessibleByMouse);
            tb->setTextFormat(Qt::RichText);
            tb->setText(str.trimmed());
            connect(tb, &QLabel::linkActivated,
                    this, &help_widget::anchor_clicked);
            info_layout->addWidget(tb);
          }
        } requirement_vector_iterate_end;
 
        requirement_vector_iterate(&pimprove->obsolete_by, pobs) {
          if (pobs->source.kind == VUT_ADVANCE
              && pobs->source.value.advance == padvance) {
            str = _("Obsoletes");
            str = "<b>" + str + "</b> "
              + link_me(improvement_name_translation(pimprove),
                        is_great_wonder(pimprove) ? HELP_WONDER
                        : HELP_IMPROVEMENT);
            tb = new QLabel(this);
            tb->setProperty(fonts::help_label, "true");
            tb->setTextInteractionFlags(Qt::LinksAccessibleByMouse);
            tb->setTextFormat(Qt::RichText);
            tb->setText(str.trimmed());
            connect(tb, &QLabel::linkActivated,
                    this, &help_widget::anchor_clicked);
            info_layout->addWidget(tb);
          }
        } requirement_vector_iterate_end;
      }
    } improvement_iterate_end;
 
    unit_type_iterate(punittype) {
 
      if (!is_tech_req_for_utype(punittype, padvance)) {
        continue;
      }
 
      str = _("Allows");
      str = "<b>" + str + "</b> "
        + link_me(utype_name_translation(punittype), HELP_UNIT);
      tb = new QLabel(this);
      tb->setProperty(fonts::help_label, "true");
      tb->setTextInteractionFlags(Qt::LinksAccessibleByMouse);
      tb->setTextFormat(Qt::RichText);
      tb->setText(str.trimmed());
      connect(tb, &QLabel::linkActivated,
              this, &help_widget::anchor_clicked);
      info_layout->addWidget(tb);
    } unit_type_iterate_end;
 
    info_panel_done();
    helptext_advance(buffer, sizeof(buffer), client.conn.playing,
                     topic->text, n);
    text_browser->setPlainText(buffer);
  } else {
    set_topic_other(topic, title);
  }
}
 
/**********************************************************************/
static canvas *terrain_canvas(struct terrain *terrain,
                              const struct extra_type *resource,
                              enum extra_cause cause)
{
  struct canvas *canvas;
  struct drawn_sprite sprs[80];
  int canvas_y, count, i, width, height;
  struct extra_type *pextra;
 
  width = tileset_full_tile_width(tileset);
  height = tileset_full_tile_height(tileset);
  canvas_y = height - tileset_tile_height(tileset);
 
  canvas = qtg_canvas_create(width, height);
  canvas->map_pixmap.fill(Qt::transparent);
  for (i = 0; i < 3; ++i) {
    count = fill_basic_terrain_layer_sprite_array(tileset, sprs,
                                                  i, terrain);
    put_drawn_sprites(canvas, 1.0f, 0, canvas_y, count, sprs, false);
  }
 
  pextra = nullptr;
  if (cause != EC_COUNT) {
    extra_type_by_cause_iterate(cause, e) {
      pextra = e;
      break;
    } extra_type_by_cause_iterate_end;
 
    count = fill_basic_extra_sprite_array(tileset, sprs, pextra);
    put_drawn_sprites(canvas, 1.0f, 0, canvas_y, count, sprs, false);
  }
 
  if (resource != nullptr) {
    count = fill_basic_extra_sprite_array(tileset, sprs, resource);
    put_drawn_sprites(canvas, 1.0f, 0, canvas_y, count, sprs, false);
  }
 
  return canvas;
}
 
/**********************************************************************/
QLayout *help_widget::create_terrain_widget(const QString &title,
                                            const struct canvas *image,
                                            const QString &legend,
                                            const QString &tooltip)
{
  QGraphicsDropShadowEffect *effect;
  QLabel *label;
  QGridLayout *layout = new QGridLayout();
 
  label = new QLabel();
  effect = new QGraphicsDropShadowEffect(label);
  effect->setBlurRadius(3);
  effect->setOffset(0, 2);
  label->setGraphicsEffect(effect);
  label->setPixmap(image->map_pixmap);
  layout->addWidget(label, 0, 0, 2, 1);
 
  label = new QLabel(title);
  label->setTextFormat(Qt::PlainText);
  layout->addWidget(label, 0, 1, Qt::AlignBottom);
  label->setProperty(fonts::default_font, "true");
 
  label = new QLabel(legend);
  label->setTextFormat(Qt::PlainText);
  layout->addWidget(label, 1, 1, Qt::AlignTop);
  label->setProperty(fonts::help_label, "true");
 
  if (!tooltip.isEmpty()) {
    label->setToolTip(tooltip);
    label->setCursor(Qt::WhatsThisCursor);
  }
 
  layout->setColumnStretch(0, 0);
  layout->setColumnStretch(1, 100);
 
  return layout;
}
 
/**********************************************************************/
void help_widget::set_topic_terrain(const help_item *topic,
                                      const char *title)
{
  char buffer[MAX_HELP_TEXT_SIZE];
  struct terrain *pterrain, *max;
  QVBoxLayout *vbox;
  bool show_panel = false;
  QScrollArea *area;
  QWidget *panel;
  QString str;
 
  pterrain = terrain_by_translated_name(title);
  if (pterrain) {
    struct universal for_terr;
    canvas *canvas;
 
    for_terr.kind = VUT_TERRAIN;
    for_terr.value.terrain = pterrain;
 
    helptext_terrain(buffer, sizeof(buffer), client.conn.playing,
                     topic->text, pterrain);
    text_browser->setPlainText(buffer);
 
    // Create information panel
    show_info_panel();
    max = terrain_max_values();
 
    // Create terrain icon. Use shadow to help distinguish terrain.
    canvas = terrain_canvas(pterrain);
    add_info_pixmap(&canvas->map_pixmap, true);
    qtg_canvas_free(canvas);
 
    add_info_progress(_("Food:"), pterrain->output[O_FOOD],
                      0, max->output[O_FOOD]);
    add_info_progress(_("Production:"), pterrain->output[O_SHIELD],
                      0, max->output[O_SHIELD]);
    add_info_progress(_("Trade:"), pterrain->output[O_TRADE],
                      0, max->output[O_TRADE]);
 
    add_info_separator();
 
    add_info_progress(_("Move cost:"), pterrain->movement_cost,
                      0, max->movement_cost);
    add_info_progress(_("Defense bonus:"), MIN(100, pterrain->defense_bonus),
                      0, 100,
                      // TRANS: Display a percentage, eg "50%".
                      QString(_("%1%")).arg(pterrain->defense_bonus));
 
    add_info_separator();
 
    if (pterrain->cultivate_result != T_NONE
        && action_id_univs_not_blocking(ACTION_CULTIVATE,
                                        nullptr, &for_terr)) {
      QLabel *tb;
      char cult_buffer[1024];
 
      fc_snprintf(cult_buffer, sizeof(cult_buffer), PL_("%d turn", "%d turns",
                                                        pterrain->cultivate_time),
                  pterrain->cultivate_time);
      str = N_("Cultiv. Rslt/Time:");
      str = str + link_me(terrain_name_translation(pterrain->cultivate_result),
                          HELP_TERRAIN)
            + QString(cult_buffer).toHtmlEscaped();
      tb = new QLabel(this);
      tb->setProperty(fonts::help_label, "true");
      tb->setTextInteractionFlags(Qt::LinksAccessibleByMouse);
      tb->setTextFormat(Qt::RichText);
      tb->setText(str.trimmed());
      connect(tb, &QLabel::linkActivated,
              this, &help_widget::anchor_clicked);
      info_layout->addWidget(tb);
    }
 
    if (pterrain->plant_result != T_NONE
        && action_id_univs_not_blocking(ACTION_PLANT, nullptr, &for_terr)) {
      QLabel *tb;
      char plant_buffer[1024];
 
      fc_snprintf(plant_buffer, sizeof(plant_buffer), PL_("%d turn", "%d turns",
                                                          pterrain->plant_time),
                  pterrain->plant_time);
      str = N_("Plant Rslt/Time:");
      str = str + link_me(terrain_name_translation(pterrain->plant_result),
                          HELP_TERRAIN)
            + QString(plant_buffer).toHtmlEscaped();
      tb = new QLabel(this);
      tb->setProperty(fonts::help_label, "true");
      tb->setTextInteractionFlags(Qt::LinksAccessibleByMouse);
      tb->setTextFormat(Qt::RichText);
      tb->setText(str.trimmed());
      connect(tb, &QLabel::linkActivated,
              this, &help_widget::anchor_clicked);
      info_layout->addWidget(tb);
    }
 
    if (pterrain->transform_result != T_NONE
        && action_id_univs_not_blocking(ACTION_TRANSFORM_TERRAIN,
                                        nullptr, &for_terr)) {
      QLabel *tb;
      char tf_buffer[1024];
 
      fc_snprintf(tf_buffer, sizeof(tf_buffer), PL_("%d turn", "%d turns",
                                                    pterrain->transform_time),
                  pterrain->transform_time);
      str = N_("Trans. Rslt/Time:");
      str = str + link_me(terrain_name_translation(pterrain->transform_result),
                          HELP_TERRAIN)
            + QString(tf_buffer).toHtmlEscaped();
      tb = new QLabel(this);
      tb->setProperty(fonts::help_label, "true");
      tb->setTextInteractionFlags(Qt::LinksAccessibleByMouse);
      tb->setTextFormat(Qt::RichText);
      tb->setText(str.trimmed());
      connect(tb, &QLabel::linkActivated,
              this, &help_widget::anchor_clicked);
      info_layout->addWidget(tb);
    }
 
    if (action_id_univs_not_blocking(ACTION_IRRIGATE, nullptr, &for_terr)) {
      // TRANS: This and similar literal strings interpreted as (Qt) HTML
      add_extras_of_act_for_terrain(pterrain, ACTIVITY_IRRIGATE,
                                    _("Build as irrigation"));
    }
    if (action_id_univs_not_blocking(ACTION_MINE, nullptr, &for_terr)) {
      add_extras_of_act_for_terrain(pterrain, ACTIVITY_MINE,
                                    _("Build as mine"));
    }
    if (action_id_univs_not_blocking(ACTION_ROAD, nullptr, &for_terr)) {
      add_extras_of_act_for_terrain(pterrain, ACTIVITY_GEN_ROAD,
                                    _("Build as road"));
    }
    if (action_id_univs_not_blocking(ACTION_BASE, nullptr, &for_terr)) {
      add_extras_of_act_for_terrain(pterrain, ACTIVITY_BASE,
                                    _("Build as base"));
    }
 
    info_panel_done();
 
    // Create bottom widget
    panel = new QWidget();
    vbox = new QVBoxLayout(panel);
 
    if (*(pterrain->resources)) {
      struct extra_type **r;
 
      // TODO: include resource frequency information
      for (r = pterrain->resources; *r; r++) {
        canvas = terrain_canvas(pterrain, *r);
        vbox->addLayout(create_terrain_widget(
          extra_name_translation(*r),
          canvas,
          // TRANS: %1 food, %2 shields, %3 trade
          QString(_("Tile output becomes %1, %2, %3."))
            .arg(pterrain->output[O_FOOD]   + (*r)->data.resource->output[O_FOOD])
            .arg(pterrain->output[O_SHIELD] + (*r)->data.resource->output[O_SHIELD])
            .arg(pterrain->output[O_TRADE]  + (*r)->data.resource->output[O_TRADE]),
          // TRANS: Tooltip decorating strings like "1, 2, 3".
          _("Output (Food, Shields, Trade) of a tile where the resource is "
            "present.")));
        qtg_canvas_free(canvas);
        show_panel = true;
      }
    }
 
    vbox->addStretch(100);
    vbox->setSizeConstraint(QLayout::SetMinimumSize);
    if (show_panel) {
      area = new QScrollArea();
      area->setWidget(panel);
      set_bottom_panel(area);
    } else {
      panel->deleteLater();
    }
 
    delete max;
  } else {
    set_topic_other(topic, title);
  }
}
 
/**********************************************************************/
bool help_widget::set_topic_extra(const help_item *topic,
                                  const char *title)
{
  char buffer[MAX_HELP_TEXT_SIZE];
  struct extra_type *pextra = extra_type_by_translated_name(title);
 
  if (pextra) {
    canvas *canvas;
    int canvas_y, count, width, height;
    struct drawn_sprite sprs[80];
 
    helptext_extra(buffer, sizeof(buffer), client.conn.playing,
                  topic->text, pextra);
    text_browser->setPlainText(buffer);
 
    // Create information panel
    show_info_panel();
 
    // Create extra icon.
    width = tileset_full_tile_width(tileset);
    height = tileset_full_tile_height(tileset);
    canvas_y = height - tileset_tile_height(tileset);
    canvas = qtg_canvas_create(width, height);
    canvas->map_pixmap.fill(Qt::transparent);
    count = fill_basic_extra_sprite_array(tileset, sprs, pextra);
    put_drawn_sprites(canvas, 1.0f, 0, canvas_y, count, sprs, false);
    add_info_pixmap(&canvas->map_pixmap, true);
    qtg_canvas_free(canvas);
 
    return false;
  } else {
    set_topic_other(topic, title);
 
    return true;
  }
}
 
/**********************************************************************/
void help_widget::set_topic_specialist(const help_item *topic,
                                         const char *title)
{
  char buffer[MAX_HELP_TEXT_SIZE];
  struct specialist *pspec = specialist_by_translated_name(title);
  if (pspec) {
    helptext_specialist(buffer, sizeof(buffer), client.conn.playing,
                        topic->text, pspec);
    text_browser->setPlainText(buffer);
  } else {
    set_topic_other(topic, title);
  }
}
 
/**********************************************************************/
void help_widget::set_topic_government(const help_item *topic,
                                         const char *title)
{
  char buffer[MAX_HELP_TEXT_SIZE];
  struct government *pgov = government_by_translated_name(title);
  if (pgov) {
    helptext_government(buffer, sizeof(buffer), client.conn.playing,
                        topic->text, pgov);
    text_browser->setPlainText(buffer);
  } else {
    set_topic_other(topic, title);
  }
}
 
/**********************************************************************/
void help_widget::set_topic_nation(const help_item *topic,
                                     const char *title)
{
  char buffer[MAX_HELP_TEXT_SIZE];
  struct nation_type *pnation = nation_by_translated_plural(title);
  if (pnation) {
    helptext_nation(buffer, sizeof(buffer), pnation, topic->text);
    text_browser->setPlainText(buffer);
  } else {
    set_topic_other(topic, title);
  }
}
 
/**********************************************************************/
void help_widget::set_topic_goods(const help_item* topic,
                                  const char *title)
{
  char buffer[MAX_HELP_TEXT_SIZE];
  struct goods_type *pgood = goods_by_translated_name(title);
  if (pgood) {
    helptext_goods(buffer, sizeof(buffer), client.conn.playing,
                   topic->text, pgood);
    text_browser->setText(buffer);
  } else {
    set_topic_other(topic, title);
  }
}
 
/**********************************************************************/
struct terrain *help_widget::terrain_max_values()
{
  Terrain_type_id i, count;
  struct terrain *terrain;
  struct terrain *max = new struct terrain;
 
  max->base_time = 0;
  max->defense_bonus = 0;
  max->irrigation_food_incr = 0;
  max->irrigation_time = 0;
  max->mining_shield_incr = 0;
  max->mining_time = 0;
  max->movement_cost = 0;
  max->output[O_FOOD] = 0;
  max->output[O_GOLD] = 0;
  max->output[O_LUXURY] = 0;
  max->output[O_SCIENCE] = 0;
  max->output[O_SHIELD] = 0;
  max->output[O_TRADE] = 0;
  max->pillage_time = 0;
  max->road_output_incr_pct[O_FOOD] = 0;
  max->road_output_incr_pct[O_GOLD] = 0;
  max->road_output_incr_pct[O_LUXURY] = 0;
  max->road_output_incr_pct[O_SCIENCE] = 0;
  max->road_output_incr_pct[O_SHIELD] = 0;
  max->road_output_incr_pct[O_TRADE] = 0;
  max->road_time = 0;
  max->transform_time = 0;
  count = terrain_count();
  for (i = 0; i < count; ++i) {
    terrain = terrain_by_number(i);
#define SET_MAX(v) \
    max->v = max->v > terrain->v ? max->v : terrain->v
    SET_MAX(base_time);
    SET_MAX(defense_bonus);
    SET_MAX(irrigation_food_incr);
    SET_MAX(irrigation_time);
    SET_MAX(mining_shield_incr);
    SET_MAX(mining_time);
    SET_MAX(movement_cost);
    SET_MAX(output[O_FOOD]);
    SET_MAX(output[O_GOLD]);
    SET_MAX(output[O_LUXURY]);
    SET_MAX(output[O_SCIENCE]);
    SET_MAX(output[O_SHIELD]);
    SET_MAX(output[O_TRADE]);
    SET_MAX(pillage_time);
    SET_MAX(road_output_incr_pct[O_FOOD]);
    SET_MAX(road_output_incr_pct[O_GOLD]);
    SET_MAX(road_output_incr_pct[O_LUXURY]);
    SET_MAX(road_output_incr_pct[O_SCIENCE]);
    SET_MAX(road_output_incr_pct[O_SHIELD]);
    SET_MAX(road_output_incr_pct[O_TRADE]);
    SET_MAX(road_time);
    SET_MAX(transform_time);
#undef SET_MAX
  }
  return max;
}
 
/**********************************************************************/
struct unit_type *help_widget::uclass_max_values(struct unit_class *uclass)
{
  struct unit_type *max = new struct unit_type;
 
  max->uclass = uclass;
  max->attack_strength = 0;
  max->bombard_rate = 0;
  max->build_cost = 0;
  max->city_size = 0;
  max->convert_time = 0;
  max->defense_strength = 0;
  max->firepower = 0;
  max->fuel = 0;
  max->happy_cost = 0;
  max->hp = 0;
  max->move_rate = 0;
  max->pop_cost = 0;
  max->upkeep[O_FOOD] = 0;
  max->upkeep[O_GOLD] = 0;
  max->upkeep[O_LUXURY] = 0;
  max->upkeep[O_SCIENCE] = 0;
  max->upkeep[O_SHIELD] = 0;
  max->upkeep[O_TRADE] = 0;
  max->vision_radius_sq = 0;
 
  unit_type_iterate(utype) {
    if (utype->uclass == uclass) {
 
#define SET_MAX(v)                                      \
      max->v = max->v > utype->v ? max->v : utype->v
 
      SET_MAX(attack_strength);
      SET_MAX(bombard_rate);
      SET_MAX(build_cost);
      SET_MAX(city_size);
      SET_MAX(convert_time);
      SET_MAX(defense_strength);
      SET_MAX(firepower);
      SET_MAX(fuel);
      SET_MAX(happy_cost);
      SET_MAX(hp);
      SET_MAX(move_rate);
      SET_MAX(pop_cost);
      SET_MAX(upkeep[O_FOOD]);
      SET_MAX(upkeep[O_GOLD]);
      SET_MAX(upkeep[O_LUXURY]);
      SET_MAX(upkeep[O_SCIENCE]);
      SET_MAX(upkeep[O_SHIELD]);
      SET_MAX(upkeep[O_TRADE]);
      SET_MAX(vision_radius_sq);
 
#undef SET_MAX
 
    }
  } unit_type_iterate_end
 
  return max;
}