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#include "fontpanel.h"

#include <QtGui/QLabel>

#include <QtGui/QComboBox>

#include <QtGui/QFormLayout>

#include <QtGui/QSpacerItem>

#include <QtGui/QFontComboBox>

#include <QtCore/QTimer>

#include <QtGui/QLineEdit>

QT_BEGIN_NAMESPACE

FontPanel::FontPanel(QWidget *parentWidget) :

    QGroupBox(parentWidget),

    m_previewLineEdit(new QLineEdit),

    m_writingSystemComboBox(new QComboBox),

    m_familyComboBox(new QFontComboBox),

    m_styleComboBox(new QComboBox),

    m_pointSizeComboBox(new QComboBox),

    m_previewFontUpdateTimer(0)

{

    setTitle(tr("Font"));

    QFormLayout *formLayout = new QFormLayout(this);

    // writing systems

    m_writingSystemComboBox->setEditable(false);

    QList<QFontDatabase::WritingSystem> writingSystems = m_fontDatabase.writingSystems();

    writingSystems.push_front(QFontDatabase::Any);

    foreach (QFontDatabase::WritingSystem ws, writingSystems)

        m_writingSystemComboBox->addItem(QFontDatabase::writingSystemName(ws), QVariant(ws));

    connect(m_writingSystemComboBox, SIGNAL(currentIndexChanged(int)), this, SLOT(slotWritingSystemChanged(int)));

    formLayout->addRow(tr("&Writing system"), m_writingSystemComboBox);

    connect(m_familyComboBox, SIGNAL(currentFontChanged(QFont)), this, SLOT(slotFamilyChanged(QFont)));

    formLayout->addRow(tr("&Family"), m_familyComboBox);

    m_styleComboBox->setEditable(false);

    connect(m_styleComboBox,  SIGNAL(currentIndexChanged(int)),  this, SLOT(slotStyleChanged(int)));

    formLayout->addRow(tr("&Style"), m_styleComboBox);

    m_pointSizeComboBox->setEditable(false);

    connect(m_pointSizeComboBox, SIGNAL(currentIndexChanged(int)),  this, SLOT(slotPointSizeChanged(int)));

    formLayout->addRow(tr("&Point size"), m_pointSizeComboBox);

    m_previewLineEdit->setReadOnly(true);

    formLayout->addRow(m_previewLineEdit);

    setWritingSystem(QFontDatabase::Any);

}

QFont FontPanel::selectedFont() const

{

    QFont rc = m_familyComboBox->currentFont();

    const QString family = rc.family();

    rc.setPointSize(pointSize());

    const QString styleDescription = styleString();

    if (styleDescription.contains(QLatin1String("Italic")))

        rc.setStyle(QFont::StyleItalic);

    else if (styleDescription.contains(QLatin1String("Oblique")))

        rc.setStyle(QFont::StyleOblique);

    else

        rc.setStyle(QFont::StyleNormal);

    rc.setBold(m_fontDatabase.bold(family, styleDescription));

    // Weight < 0 asserts...

    const int weight = m_fontDatabase.weight(family, styleDescription);

    if (weight >= 0)

        rc.setWeight(weight);

    return rc;

}

void FontPanel::setSelectedFont(const QFont &f)

{

    m_familyComboBox->setCurrentFont(f);

    if (m_familyComboBox->currentIndex() < 0) {

        // family not in writing system - find the corresponding one?

        QList<QFontDatabase::WritingSystem> familyWritingSystems = m_fontDatabase.writingSystems(f.family());

        if (familyWritingSystems.empty())

            return;

        setWritingSystem(familyWritingSystems.front());

        m_familyComboBox->setCurrentFont(f);

    }

    updateFamily(family());

    const int pointSizeIndex = closestPointSizeIndex(f.pointSize());

    m_pointSizeComboBox->setCurrentIndex( pointSizeIndex);

    const QString styleString = m_fontDatabase.styleString(f);

    const int styleIndex = m_styleComboBox->findText(styleString);

    m_styleComboBox->setCurrentIndex(styleIndex);

    slotUpdatePreviewFont();

}

QFontDatabase::WritingSystem FontPanel::writingSystem() const

{

    const int currentIndex = m_writingSystemComboBox->currentIndex();

    if ( currentIndex == -1)

        return QFontDatabase::Latin;

    return static_cast<QFontDatabase::WritingSystem>(m_writingSystemComboBox->itemData(currentIndex).toInt());

}

QString FontPanel::family() const

{

    const int currentIndex = m_familyComboBox->currentIndex();

    return currentIndex != -1 ?  m_familyComboBox->currentFont().family() : QString();

}

int FontPanel::pointSize() const

{

    const int currentIndex = m_pointSizeComboBox->currentIndex();

    return currentIndex != -1 ? m_pointSizeComboBox->itemData(currentIndex).toInt() : 9;

}

QString FontPanel::styleString() const

{

    const int currentIndex = m_styleComboBox->currentIndex();

    return currentIndex != -1 ? m_styleComboBox->itemText(currentIndex) : QString();

}

void FontPanel::setWritingSystem(QFontDatabase::WritingSystem ws)

{

    m_writingSystemComboBox->setCurrentIndex(m_writingSystemComboBox->findData(QVariant(ws)));

    updateWritingSystem(ws);

}

void FontPanel::slotWritingSystemChanged(int)

{

    updateWritingSystem(writingSystem());

    delayedPreviewFontUpdate();

}

void FontPanel::slotFamilyChanged(const QFont &)

{

    updateFamily(family());

    delayedPreviewFontUpdate();

}

void FontPanel::slotStyleChanged(int)

{

    updatePointSizes(family(), styleString());

    delayedPreviewFontUpdate();

}

void FontPanel::slotPointSizeChanged(int)

{

    delayedPreviewFontUpdate();

}

void FontPanel::updateWritingSystem(QFontDatabase::WritingSystem ws)

{

    m_previewLineEdit->setText(QFontDatabase::writingSystemSample(ws));

    m_familyComboBox->setWritingSystem (ws);

    // Current font not in WS ... set index 0.

    if (m_familyComboBox->currentIndex() < 0) {

        m_familyComboBox->setCurrentIndex(0);

        updateFamily(family());

    }

}

void FontPanel::updateFamily(const QString &family)

{

    // Update styles and trigger update of point sizes.

    // Try to maintain selection or select normal

    const QString oldStyleString = styleString();

    const QStringList styles = m_fontDatabase.styles(family);

    const bool hasStyles = !styles.empty();

    m_styleComboBox->setCurrentIndex(-1);

    m_styleComboBox->clear();

    m_styleComboBox->setEnabled(hasStyles);

    int normalIndex = -1;

    const QString normalStyle = QLatin1String("Normal");

    if (hasStyles) {

        foreach (const QString &style, styles) {

            // try to maintain selection or select 'normal' preferably

            const int newIndex = m_styleComboBox->count();

            m_styleComboBox->addItem(style);

            if (oldStyleString == style) {

                m_styleComboBox->setCurrentIndex(newIndex);

            } else {

                if (oldStyleString ==  normalStyle)

                    normalIndex = newIndex;

            }

        }

        if (m_styleComboBox->currentIndex() == -1 && normalIndex != -1)

            m_styleComboBox->setCurrentIndex(normalIndex);

    }

    updatePointSizes(family, styleString());

}

int FontPanel::closestPointSizeIndex(int desiredPointSize) const

{

    //  try to maintain selection or select closest.

    int closestIndex = -1;

    int closestAbsError = 0xFFFF;

    const int pointSizeCount = m_pointSizeComboBox->count();

    for (int i = 0; i < pointSizeCount; i++) {

        const int itemPointSize = m_pointSizeComboBox->itemData(i).toInt();

        const int absError = qAbs(desiredPointSize - itemPointSize);

        if (absError < closestAbsError) {

            closestIndex  = i;

            closestAbsError = absError;

            if (closestAbsError == 0)

                break;

        } else {    // past optimum

            if (absError > closestAbsError) {

                break;

            }

        }

    }

    return closestIndex;

}

void FontPanel::updatePointSizes(const QString &family, const QString &styleString)

{

    const int oldPointSize = pointSize();

    QList<int> pointSizes =  m_fontDatabase.pointSizes(family, styleString);

    if (pointSizes.empty())

        pointSizes = QFontDatabase::standardSizes();

    const bool hasSizes = !pointSizes.empty();

    m_pointSizeComboBox->clear();

    m_pointSizeComboBox->setEnabled(hasSizes);

    m_pointSizeComboBox->setCurrentIndex(-1);

    //  try to maintain selection or select closest.

    if (hasSizes) {

        QString n;

        foreach (int pointSize, pointSizes)

            m_pointSizeComboBox->addItem(n.setNum(pointSize), QVariant(pointSize));

        const int closestIndex = closestPointSizeIndex(oldPointSize);

        if (closestIndex != -1)

            m_pointSizeComboBox->setCurrentIndex(closestIndex);

    }

}

void FontPanel::slotUpdatePreviewFont()

{

    m_previewLineEdit->setFont(selectedFont());

}

void FontPanel::delayedPreviewFontUpdate()

{

    if (!m_previewFontUpdateTimer) {

        m_previewFontUpdateTimer = new QTimer(this);

        connect(m_previewFontUpdateTimer, SIGNAL(timeout()), this, SLOT(slotUpdatePreviewFont()));

        m_previewFontUpdateTimer->setInterval(0);

        m_previewFontUpdateTimer->setSingleShot(true);

    }

    if (m_previewFontUpdateTimer->isActive())

        return;

    m_previewFontUpdateTimer->start();

}

QT_END_NAMESPACE