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//! [1]

#include "googlesuggest.h"

#define GSUGGEST_URL "http://google.com/complete/search?output=toolbar&q=%1"

//! [1]

//! [2]

GSuggestCompletion::GSuggestCompletion(QLineEdit *parent): QObject(parent), editor(parent)

{

    popup = new QTreeWidget;

    popup->setWindowFlags(Qt::Popup);

    popup->setFocusPolicy(Qt::NoFocus);

    popup->setFocusProxy(parent);

    popup->setMouseTracking(true);

    popup->setColumnCount(2);

    popup->setUniformRowHeights(true);

    popup->setRootIsDecorated(false);

    popup->setEditTriggers(QTreeWidget::NoEditTriggers);

    popup->setSelectionBehavior(QTreeWidget::SelectRows);

    popup->setFrameStyle(QFrame::Box | QFrame::Plain);

    popup->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

    popup->header()->hide();

    popup->installEventFilter(this);

    connect(popup, SIGNAL(itemClicked(QTreeWidgetItem*,int)),

            SLOT(doneCompletion()));

    timer = new QTimer(this);

    timer->setSingleShot(true);

    timer->setInterval(500);

    connect(timer, SIGNAL(timeout()), SLOT(autoSuggest()));

    connect(editor, SIGNAL(textEdited(QString)), timer, SLOT(start()));

    connect(&networkManager, SIGNAL(finished(QNetworkReply*)),

            this, SLOT(handleNetworkData(QNetworkReply*)));

}

//! [2]

//! [3]

GSuggestCompletion::~GSuggestCompletion()

{

    delete popup;

}

//! [3]

//! [4]

bool GSuggestCompletion::eventFilter(QObject *obj, QEvent *ev)

{

    if (obj != popup)

        return false;

    if (ev->type() == QEvent::MouseButtonPress) {

        popup->hide();

        editor->setFocus();

        return true;

    }

    if (ev->type() == QEvent::KeyPress) {

        bool consumed = false;

        int key = static_cast<QKeyEvent*>(ev)->key();

        switch (key) {

        case Qt::Key_Enter:

        case Qt::Key_Return:

            doneCompletion();

            consumed = true;

        case Qt::Key_Escape:

            editor->setFocus();

            popup->hide();

            consumed = true;

        case Qt::Key_Up:

        case Qt::Key_Down:

        case Qt::Key_Home:

        case Qt::Key_End:

        case Qt::Key_PageUp:

        case Qt::Key_PageDown:

            break;

        default:

            editor->setFocus();

            editor->event(ev);

            popup->hide();

            break;

        }

        return consumed;

    }

    return false;

}

//! [4]

//! [5]

void GSuggestCompletion::showCompletion(const QStringList &choices, const QStringList &hits)

{

    if (choices.isEmpty() || choices.count() != hits.count())

        return;

    const QPalette &pal = editor->palette();

    QColor color = pal.color(QPalette::Disabled, QPalette::WindowText);

    popup->setUpdatesEnabled(false);

    popup->clear();

    for (int i = 0; i < choices.count(); ++i) {

        QTreeWidgetItem * item;

        item = new QTreeWidgetItem(popup);

        item->setText(0, choices[i]);

        item->setText(1, hits[i]);

        item->setTextAlignment(1, Qt::AlignRight);

        item->setTextColor(1, color);

    }

    popup->setCurrentItem(popup->topLevelItem(0));

    popup->resizeColumnToContents(0);

    popup->resizeColumnToContents(1);

    popup->adjustSize();

    popup->setUpdatesEnabled(true);

    int h = popup->sizeHintForRow(0) * qMin(7, choices.count()) + 3;

    popup->resize(popup->width(), h);

    popup->move(editor->mapToGlobal(QPoint(0, editor->height())));

    popup->setFocus();

    popup->show();

}

//! [5]

//! [6]

void GSuggestCompletion::doneCompletion()

{

    timer->stop();

    popup->hide();

    editor->setFocus();

    QTreeWidgetItem *item = popup->currentItem();

    if (item) {

        editor->setText(item->text(0));

        QMetaObject::invokeMethod(editor, "returnPressed");

    }

}

//! [6]

//! [7]

void GSuggestCompletion::autoSuggest()

{

    QString str = editor->text();

    QString url = QString(GSUGGEST_URL).arg(str);

    networkManager.get(QNetworkRequest(QString(url)));

}

//! [7]

//! [8]

void GSuggestCompletion::preventSuggest()

{

    timer->stop();

}

//! [8]

//! [9]

void GSuggestCompletion::handleNetworkData(QNetworkReply *networkReply)

{

    QUrl url = networkReply->url();

    if (!networkReply->error()) {

        QStringList choices;

        QStringList hits;

        QByteArray response(networkReply->readAll());

        QXmlStreamReader xml(response);

        while (!xml.atEnd()) {

            xml.readNext();

            if (xml.tokenType() == QXmlStreamReader::StartElement)

                if (xml.name() == "suggestion") {

                    QStringRef str = xml.attributes().value("data");

                    choices << str.toString();

                }

            if (xml.tokenType() == QXmlStreamReader::StartElement)

                if (xml.name() == "num_queries") {

                    QStringRef str = xml.attributes().value("int");

                    hits << str.toString();

                }

        }

        showCompletion(choices, hits);

    }

    networkReply->deleteLater();

}

//! [9]