Checker.cpp

/* QtSpell - Spell checking for Qt text widgets.
 * Copyright (c) 2014 Sandro Mani
 *
 *    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 of the License, 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.
 *
 *    You should have received a copy of the GNU General Public License along
 *    with this program; if not, write to the Free Software Foundation, Inc.,
 *    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "QtSpell.hpp"
#include "Codetable.hpp"

#include <enchant++.h>
#include <QApplication>
#include <QLibraryInfo>
#include <QLocale>
#include <QMenu>
#include <QTranslator>
#include <QtDebug>

static void dict_describe_cb(const char* const lang_tag,
                                                         const char* const /*provider_name*/,
                                                         const char* const /*provider_desc*/,
                                                         const char* const /*provider_file*/,
                                                         void* user_data)
{
        QList<QString>* languages = static_cast<QList<QString>*>(user_data);
        languages->append(lang_tag);
}

static enchant::Broker* get_enchant_broker() {
#ifdef QTSPELL_ENCHANT2
    static enchant::Broker broker;
    return &broker;
#else
    return enchant::Broker::instance();
#endif
}


class TranslationsInit {
public:
        TranslationsInit(){
                QString translationsPath = QLibraryInfo::location(QLibraryInfo::TranslationsPath);
#ifdef Q_OS_WIN
                QDir packageDir = QDir(QString("%1/../").arg(QApplication::applicationDirPath()));
                translationsPath = packageDir.absolutePath() + translationsPath.mid(QLibraryInfo::location(QLibraryInfo::PrefixPath).length());
#endif
                spellTranslator.load("QtSpell_" + QLocale::system().name(), translationsPath);
                QApplication::instance()->installTranslator(&spellTranslator);
        }
private:
        QTranslator spellTranslator;
};


namespace QtSpell {

bool checkLanguageInstalled(const QString &lang)
{
        return get_enchant_broker()->dict_exists(lang.toStdString());
}

Checker::Checker(QObject* parent)
        : QObject(parent),
          m_speller(0),
          m_decodeCodes(false),
          m_spellingCheckbox(false),
          m_spellingEnabled(true)
{
        static TranslationsInit tsInit;
        Q_UNUSED(tsInit);

        // setLanguageInternal: setLanguage is virtual and cannot be called in the constructor
        setLanguageInternal("");
}

Checker::~Checker()
{
        delete m_speller;
}

bool Checker::setLanguage(const QString &lang)
{
        bool success = setLanguageInternal(lang);
        if(isAttached()){
                checkSpelling();
        }
        return success;
}

bool Checker::setLanguageInternal(const QString &lang)
{
        delete m_speller;
        m_speller = 0;
        m_lang = lang;

        // Determine language from system locale
        if(m_lang.isEmpty()){
                m_lang = QLocale::system().name();
                if(m_lang.toLower() == "c" || m_lang.isEmpty()){
                        qWarning() << "Cannot use system locale " << m_lang;
                        m_lang = QString::null;
                        return false;
                }
        }

        // Request dictionary
        try {
                m_speller = get_enchant_broker()->request_dict(m_lang.toStdString());
        } catch(enchant::Exception& e) {
                qWarning() << "Failed to load dictionary: " << e.what();
                m_lang = QString::null;
                return false;
        }

        return true;
}

void Checker::addWordToDictionary(const QString &word)
{
        if(m_speller){
                m_speller->add(word.toUtf8().data());
        }
}

bool Checker::checkWord(const QString &word) const
{
        if(!m_speller || !m_spellingEnabled){
                return true;
        }
        // Skip empty strings and single characters
        if(word.length() < 2){
                return true;
        }
        try{
                return m_speller->check(word.toUtf8().data());
        }catch(const enchant::Exception&){
                return true;
        }
}

void Checker::ignoreWord(const QString &word) const
{
        m_speller->add_to_session(word.toUtf8().data());
}

QList<QString> Checker::getSpellingSuggestions(const QString& word) const
{
        QList<QString> list;
        if(m_speller){
                std::vector<std::string> suggestions;
                m_speller->suggest(word.toUtf8().data(), suggestions);
                for(std::size_t i = 0, n = suggestions.size(); i < n; ++i){
                        list.append(QString::fromUtf8(suggestions[i].c_str()));
                }
        }
        return list;
}

QList<QString> Checker::getLanguageList()
{
        enchant::Broker* broker = get_enchant_broker();
        QList<QString> languages;
        broker->list_dicts(dict_describe_cb, &languages);
        qSort(languages);
        return languages;
}

QString Checker::decodeLanguageCode(const QString &lang)
{
        QString language, country, extra;
        Codetable::instance()->lookup(lang, language, country, extra);
        if(!country.isEmpty()){
                QString decoded = QString("%1 (%2)").arg(language, country);
                if(!extra.isEmpty()) {
                        decoded += QString(" [%1]").arg(extra);
                }
                return decoded;
        }else{
                return language;
        }
}

void Checker::showContextMenu(QMenu* menu, const QPoint& pos, int wordPos)
{
        QAction* insertPos = menu->actions().first();
        if(m_speller && m_spellingEnabled){
                QString word = getWord(wordPos);

                if(!checkWord(word)) {
                        QList<QString> suggestions = getSpellingSuggestions(word);
                        if(!suggestions.isEmpty()){
                                for(int i = 0, n = qMin(10, suggestions.length()); i < n; ++i){
                                        QAction* action = new QAction(suggestions[i], menu);
                                        action->setProperty("wordPos", wordPos);
                                        action->setProperty("suggestion", suggestions[i]);
                                        connect(action, SIGNAL(triggered()), this, SLOT(slotReplaceWord()));
                                        menu->insertAction(insertPos, action);
                                }
                                if(suggestions.length() > 10) {
                                        QMenu* moreMenu = new QMenu();
                                        for(int i = 10, n = suggestions.length(); i < n; ++i){
                                                QAction* action = new QAction(suggestions[i], moreMenu);
                                                action->setProperty("wordPos", wordPos);
                                                action->setProperty("suggestion", suggestions[i]);
                                                connect(action, SIGNAL(triggered()), this, SLOT(slotReplaceWord()));
                                                moreMenu->addAction(action);
                                        }
                                        QAction* action = new QAction(tr("More..."), menu);
                                        menu->insertAction(insertPos, action);
                                        action->setMenu(moreMenu);
                                }
                                menu->insertSeparator(insertPos);
                        }

                        QAction* addAction = new QAction(tr("Add \"%1\" to dictionary").arg(word), menu);
                        addAction->setData(wordPos);
                        connect(addAction, SIGNAL(triggered()), this, SLOT(slotAddWord()));
                        menu->insertAction(insertPos, addAction);

                        QAction* ignoreAction = new QAction(tr("Ignore \"%1\"").arg(word), menu);
                        ignoreAction->setData(wordPos);
                        connect(ignoreAction, SIGNAL(triggered()), this, SLOT(slotIgnoreWord()));
                        menu->insertAction(insertPos, ignoreAction);
                        menu->insertSeparator(insertPos);
                }
        }
        if(m_spellingCheckbox){
                QAction* action = new QAction(tr("Check spelling"), menu);
                action->setCheckable(true);
                action->setChecked(m_spellingEnabled);
                connect(action, SIGNAL(toggled(bool)), this, SLOT(setSpellingEnabled(bool)));
                menu->insertAction(insertPos, action);
        }
        if(m_speller && m_spellingEnabled){
                QMenu* languagesMenu = new QMenu();
                QActionGroup* actionGroup = new QActionGroup(languagesMenu);
                foreach(const QString& lang, getLanguageList()){
                        QString text = getDecodeLanguageCodes() ? decodeLanguageCode(lang) : lang;
                        QAction* action = new QAction(text, languagesMenu);
                        action->setData(lang);
                        action->setCheckable(true);
                        action->setChecked(lang == getLanguage());
                        connect(action, SIGNAL(triggered(bool)), this, SLOT(slotSetLanguage(bool)));
                        languagesMenu->addAction(action);
                        actionGroup->addAction(action);
                }
                QAction* langsAction = new QAction(tr("Languages"), menu);
                langsAction->setMenu(languagesMenu);
                menu->insertAction(insertPos, langsAction);
                menu->insertSeparator(insertPos);
        }

        menu->exec(pos);
        delete menu;
}

void Checker::slotAddWord()
{
        int wordPos = qobject_cast<QAction*>(QObject::sender())->property("wordPos").toInt();
        int start, end;
        addWordToDictionary(getWord(wordPos, &start, &end));
        checkSpelling(start, end);
}

void Checker::slotIgnoreWord()
{
        int wordPos = qobject_cast<QAction*>(QObject::sender())->property("wordPos").toInt();
        int start, end;
        ignoreWord(getWord(wordPos, &start, &end));
        checkSpelling(start, end);
}

void Checker::slotReplaceWord()
{
        QAction* action = qobject_cast<QAction*>(QObject::sender());
        int wordPos = action->property("wordPos").toInt();
        int start, end;
        getWord(wordPos, &start, &end);
        insertWord(start, end, action->property("suggestion").toString());
}

void Checker::slotSetLanguage(bool checked)
{
        if(checked) {
                QAction* action = qobject_cast<QAction*>(QObject::sender());
                QString lang = action->data().toString();
                if(!setLanguage(lang)){
                        action->setChecked(false);
                        lang = "";
                }
                emit languageChanged(lang);
        }
}

} // QtSpell