qcombobox.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

/*!
    \fn void QComboBox::activated(const QString &text)

    This signal is sent when an item in the combobox is activated by
    the user. The item's \a text is given.

*/

/*!
    \fn void QComboBox::highlighted(int index)

    This signal is sent when an item in the combobox is highlighted by
    the user. The item's \a index is given.
*/

/*!
    \fn void QComboBox::highlighted(const QString &text)

    This signal is sent when an item in the combobox is highlighted by
    the user. The item's \a text is given.
*/

/*!
    \fn void QComboBox::currentIndexChanged(int index)
    \since 4.1

    This signal is sent whenever the currentIndex in the combobox
    changes either through user interaction or programmatically. The
    item's \a index is given or -1 if the combobox becomes empty or the
    currentIndex was reset.
*/

/*!
    \fn void QComboBox::currentIndexChanged(const QString &text)
    \since 4.1

    This signal is sent whenever the currentIndex in the combobox
    changes either through user interaction or programmatically.  The
    item's \a text is given.
*/

/*!
    Constructs a combobox with the given \a parent, using the default
    model QStandardItemModel.
*/
QComboBox::QComboBox(QWidget *parent) :
    QWidget(*new QComboBoxPrivate(), parent, 0)
{
    Q_D(QComboBox);
    d->init();
}

#ifdef QT3_SUPPORT
/*!
    Use one of the constructors that doesn't take the \a name
    argument and then use setObjectName() instead.
*/
QComboBox::QComboBox(QWidget *parent, const char *name) :
    QWidget(*new QComboBoxPrivate(), parent, 0)
{
    Q_D(QComboBox);
    d->init();
    setObjectName(QString::fromAscii(name));
}

/*!
    Use one of the constructors that doesn't take the \a name
    argument and then use setObjectName() instead.
*/
QComboBox::QComboBox(bool rw, QWidget *parent, const char *name) :
    QWidget(*new QComboBoxPrivate(), parent, 0)
{
    Q_D(QComboBox);
    d->init();
    setEditable(rw);
    setObjectName(QString::fromAscii(name));
}

#endif //QT3_SUPPORT

/*!
    \class QComboBox qcombobox.h
    \brief The QComboBox widget is a combined button and popup list.

    \ingroup basic
    \mainclass

    A QComboBox provides a means of presenting a list of options to the user
    in a way that takes up the minimum amount of screen space.

    A combobox is a selection widget that displays the current item,
    and can pop up a list of selectable items. A combobox may be editable,
    allowing the user to modify each item in the list.

    Comboboxes can contain pixmaps as well as strings; the
    insertItem() and changeItem() functions are suitably overloaded.
    For editable comboboxes, the function clearEdit() is provided,
    to clear the displayed string without changing the combobox's
    contents.

    A combobox emits two signals, activated() and highlighted(), when
    a new item has been activated (selected) or highlighted (made
    current). Both signals exist in two versions, one with a
    QString argument and one with an \c int argument. If the user
    highlights or activates a pixmap, only the \c int signals are
    emitted. Whenever the text of an editable combobox is changed the
    editTextChanged() signal is emitted.

    When the user enters a new string in an editable combobox, the
    widget may or may not insert it, and it can insert it in several
    locations. The default policy is is \l AtBottom but you can change
    this using setInsertPolicy().

    It is possible to constrain the input to an editable combobox
    using QValidator; see setValidator(). By default, any input is
    accepted.

    A combobox can be populated using the insert functions,
    insertStringList() and insertItem() for example. Items can be
    changed with changeItem(). An item can be removed with
    removeItem() and all items can be removed with clear(). The text
    of the current item is returned by currentText(), and the text of
    a numbered item is returned with text(). The current item can be
    set with setCurrentIndex(). The number of items in the combobox is
    returned by count(); the maximum number of items can be set with
    setMaxCount(). You can allow editing using setEditable(). For
    editable comboboxes you can set auto-completion using
    setAutoCompletion() and whether or not the user can add duplicates
    is set with setDuplicatesEnabled().

    \image qstyle-comboboxes.png Comboboxes in the different built-in styles.

    \sa QLineEdit, QSpinBox, QRadioButton, QButtonGroup,
        {fowler}{GUI Design Handbook: Combo Box, Drop-Down List Box}
*/

void QComboBoxPrivate::init()
{
    Q_Q(QComboBox);
    q->setModel(new QStandardItemModel(0, 1, q));
    q->setFocusPolicy(Qt::WheelFocus);
    q->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Fixed);
}

QComboBoxPrivateContainer* QComboBoxPrivate::viewContainer()
{
    if (container)
        return container;

    Q_Q(QComboBox);
    container = new QComboBoxPrivateContainer(new QComboBoxListView(), q);
    container->itemView()->setModel(model);
    container->itemView()->setTextElideMode(Qt::ElideMiddle);
    QStyleOptionComboBox opt = getStyleOption();
    if (q->style()->styleHint(QStyle::SH_ComboBox_Popup, &opt, q))
        q->setItemDelegate(new QComboMenuDelegate(container->itemView(), q));
    container->setLayoutDirection(Qt::LayoutDirection(
                                    q->style()->styleHint(QStyle::SH_ComboBox_LayoutDirection,
                                                          &opt, q)));
    QObject::connect(container, SIGNAL(itemSelected(QModelIndex)),
                     q, SLOT(_q_itemSelected(QModelIndex)));
    QObject::connect(container->itemView()->selectionModel(),
                     SIGNAL(currentChanged(QModelIndex,QModelIndex)),
                     q, SLOT(_q_emitHighlighted(QModelIndex)));
    QObject::connect(container, SIGNAL(resetButton()), q, SLOT(_q_resetButton()));
    return container;
}


void QComboBoxPrivate::_q_resetButton()
{
    updateArrow(QStyle::State_None);
}

void QComboBoxPrivate::_q_dataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight)
{
    Q_Q(QComboBox);
    if (topLeft.parent() != root)
        return;

    if (sizeAdjustPolicy == QComboBox::AdjustToContents) {
        sizeHint = QSize();
        q->updateGeometry();
    }

    if (currentIndex.row() >= topLeft.row() && currentIndex.row() <= bottomRight.row()) {
        if (lineEdit) {
            lineEdit->setText(q->itemText(currentIndex.row()));
            updateLineEditGeometry();
        }
        q->update();
    }
}

void QComboBoxPrivate::_q_rowsAboutToBeInserted(const QModelIndex & parent,
                                             int /*start*/, int /*end*/)
{
    if (parent != root)
        return;
    indexBeforeChange = currentIndex.row();
}

void QComboBoxPrivate::_q_rowsInserted(const QModelIndex &parent, int start, int end)
{
    Q_UNUSED(start);
    Q_UNUSED(end);
    Q_Q(QComboBox);
    if (parent != root)
        return;

    if (sizeAdjustPolicy == QComboBox::AdjustToContents) {
        sizeHint = QSize();
        q->updateGeometry();
    }

    // set current index if combo was previously empty
    if (start == 0 && (end - start + 1) == q->count() && !currentIndex.isValid()) {
        q->setCurrentIndex(0);
    // need to emit changed if model updated index "silently"
    } else if (currentIndex.row() != indexBeforeChange) {
        if (lineEdit) {
            lineEdit->setText(q->itemText(currentIndex.row()));
            updateLineEditGeometry();
        }
        q->update();
        _q_emitCurrentIndexChanged(currentIndex.row());
    }
}

void QComboBoxPrivate::_q_rowsAboutToBeRemoved(const QModelIndex &parent, int /*start*/, int /*end*/)
{
    if (parent != root)
        return;

    indexBeforeChange = currentIndex.row();
}

void QComboBoxPrivate::_q_rowsRemoved(const QModelIndex &parent, int /*start*/, int /*end*/)
{
    Q_Q(QComboBox);
    if (parent != root)
        return;

    if (sizeAdjustPolicy == QComboBox::AdjustToContents) {
        sizeHint = QSize();
        q->updateGeometry();
    }

    // model has changed the currentIndex
    if (currentIndex.row() != indexBeforeChange) {
        if (!currentIndex.isValid() && q->count()) {
            q->setCurrentIndex(qMin(q->count() - 1, qMax(indexBeforeChange, 0)));
            return;
        }

        if (lineEdit) {
            lineEdit->setText(q->itemText(currentIndex.row()));
            updateLineEditGeometry();
        }
        q->update();
        _q_emitCurrentIndexChanged(currentIndex.row());
    }
}



QStyleOptionComboBox QComboBoxPrivate::getStyleOption() const
{
    Q_Q(const QComboBox);
    QStyleOptionComboBox opt;
    opt.init(q);
    if (!q->isEditable() && q->hasFocus())
        opt.state |= QStyle::State_Selected;
    opt.subControls = QStyle::SC_All;
    if (arrowState == QStyle::State_Sunken) {
        opt.activeSubControls = QStyle::SC_ComboBoxArrow;
        opt.state |= arrowState;
    } else {
        opt.activeSubControls = hoverControl;
    }
    opt.editable = q->isEditable();
    opt.frame = frame;
    if (currentIndex.isValid()) {
        opt.currentText = q->currentText();
        opt.currentIcon = q->itemIcon(currentIndex.row());
    }
    opt.iconSize = q->iconSize();
    if (container && container->isVisible())
        opt.state |= QStyle::State_On;

    return opt;
}

void QComboBoxPrivate::updateLineEditGeometry()
{
    if (!lineEdit)
        return;

    Q_Q(QComboBox);
    QStyleOptionComboBox opt = getStyleOption();
    QRect editRect = q->style()->subControlRect(QStyle::CC_ComboBox, &opt,
                                                QStyle::SC_ComboBoxEditField, q);
    if (!q->itemIcon(q->currentIndex()).isNull()) {
        QRect comboRect(editRect);
        editRect.setWidth(editRect.width() - q->iconSize().width() - 4);
        editRect = QStyle::alignedRect(q->layoutDirection(), Qt::AlignRight,
                                       editRect.size(), comboRect);
    }
    lineEdit->setGeometry(editRect);
}

void QComboBoxPrivate::_q_returnPressed()
{
    Q_Q(QComboBox);
    if (lineEdit && !lineEdit->text().isEmpty()) {
        QString text = lineEdit->text();
        // check for duplicates (if not enabled) and quit
        int index = -1;
        if (!duplicatesEnabled) {
            index = q->findText(text);
            if (index != -1) {
                q->setCurrentIndex(index);
                emitActivated(currentIndex);
                return;
            }
        }
        switch (insertPolicy) {
        case QComboBox::InsertAtTop:
            index = 0;
            break;
        case QComboBox::InsertAtBottom:
            index = q->count();
            break;
        case QComboBox::InsertAtCurrent:
        case QComboBox::InsertAfterCurrent:
        case QComboBox::InsertBeforeCurrent:
            if (!q->count() || !currentIndex.isValid())
                index = 0;
            else if (insertPolicy == QComboBox::InsertAtCurrent)
                q->setItemText(q->currentIndex(), text);
            else if (insertPolicy == QComboBox::InsertAfterCurrent)
                index = q->currentIndex() + 1;
            else if (insertPolicy == QComboBox::InsertBeforeCurrent)
                index = q->currentIndex();
            break;
        case QComboBox::NoInsert:
        default:
            break;
        }
        if (index >= 0) {
            q->insertItem(index, text);
            q->setCurrentIndex(index);
            emitActivated(currentIndex);
        }
    }
}

/*
    Handles auto completion.
*/
void QComboBoxPrivate::_q_complete()
{
    if (skipCompletion || !lineEdit || !autoCompletion) {
        skipCompletion = false;
        return;
    }
    QString text = lineEdit->text();
    if (!text.isEmpty()) {
        Qt::MatchFlags flags(Qt::MatchWrap|Qt::MatchStartsWith);
        if (autoCompletionCaseSensitivity == Qt::CaseSensitive)
            flags |= Qt::MatchCaseSensitive;
        QModelIndexList list = model->match(currentIndex, Qt::EditRole, text, 1, flags);
        if (!list.count())
            return;
        QString completed = model->data(list.first(), Qt::EditRole).toString();
        int start = completed.length();
        int length = text.length() - start; // negative length
        lineEdit->setText(completed);
        lineEdit->setSelection(start, length);
    }
}

void QComboBoxPrivate::_q_itemSelected(const QModelIndex &item)
{
    Q_Q(QComboBox);
    if (item != currentIndex) {
        q->setCurrentIndex(item.row());
    } else if (lineEdit) {
        lineEdit->selectAll();
        lineEdit->setText(q->itemText(currentIndex.row()));
    }
    emitActivated(currentIndex);
}

void QComboBoxPrivate::emitActivated(const QModelIndex &index)
{
    Q_Q(QComboBox);
    if (!index.isValid())
        return;
    QString text(q->model()->data(index, Qt::EditRole).toString());
    emit q->activated(index.row());
    emit q->activated(text);
}

void QComboBoxPrivate::_q_emitHighlighted(const QModelIndex &index)
{
    Q_Q(QComboBox);
    if (!index.isValid())
        return;
    QString text(q->model()->data(index, Qt::EditRole).toString());
    emit q->highlighted(index.row());
    emit q->highlighted(text);
}

void QComboBoxPrivate::_q_emitCurrentIndexChanged(int index)
{
    Q_Q(QComboBox);
    QModelIndex mi = q->model()->index(index, modelColumn, q->rootModelIndex());
    QString text;
    if (mi.isValid())
        text = q->model()->data(mi, Qt::EditRole).toString();
    emit q->currentIndexChanged(index);
    emit q->currentIndexChanged(text);
}

/*!
    Destroys the combobox.
*/
QComboBox::~QComboBox()
{
    // ### check delegateparent and delete delegate if us?
    Q_D(QComboBox);

    disconnect(d->model, SIGNAL(destroyed()),
               this, SLOT(_q_modelDestroyed()));
}

/*!
    \property QComboBox::maxVisibleItems
    \brief the maximum allowed size on screen of the combobox

    This property is ignored for non-editable comboboxes in Mac
    style.
*/

int QComboBox::maxVisibleItems() const
{
    Q_D(const QComboBox);
    return d->maxVisibleItems;
}

void QComboBox::setMaxVisibleItems(int maxItems)
{
    Q_D(QComboBox);
    if (maxItems > 0)
        d->maxVisibleItems = maxItems;
}