qheaderview.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

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#include "qheaderview.h"

#ifndef QT_NO_ITEMVIEWS
#include <qbitarray.h>
#include <qdebug.h>
#include <qevent.h>
#include <qpainter.h>
#include <qscrollbar.h>
#include <qtooltip.h>
#include <qwhatsthis.h>
#include <qstyle.h>
#include <qstyleoption.h>
#include <qvector.h>
#include <qapplication.h>
#include <qvarlengtharray.h>
#include <qabstractitemdelegate.h>
#include <qvariant.h>
#include <private/qheaderview_p.h>

/*!
    \class QHeaderView

    \brief The QHeaderView class provides a header row or header column for item views.

    \ingroup model-view
    \mainclass

    A QHeaderView displays the headers used in item views such as the
    QTableView and QTreeView classes. It takes the place of
    the \c QHeader class previously used for the same purpose, but uses
    the Qt's model/view architecture for consistency with the item view
    classes.

    The QHeaderView class is one of the \l{Model/View Classes} and is
    part of Qt's \l{Model/View Programming}{model/view framework}.

    The model gets the data for each section from the model using
    the getHeaderData() function.  You can set the data by using
    setHeaderData().

    Each header has an orientation() and a number of sections, given by
    the count() function. Sections can be moved and resized using
    moveSection() and resizeSection(); they can be hidden and shown
    with hideSection() and showSection().

    Each section of a header is described by a section ID, specified by
    its section(), and can be located at a particular visualIndex() in the
    header. A section can have a sort indicator set with
    setSortIndicator(); this indicates whether the items in the associated
    item view will be sorted in the order given by the section.

    A header can be fixed in place, or made movable with setMovable().
    It can be made clickable with setClickable(), and has resizing behavior
    in accordance with setResizeMode().

    A header emits sectionMoved() if the user moves a section,
    sectionResized() if the user resizes a section, and
    sectionClicked() and sectionHandleDoubleClicked() in response to
    mouse clicks. A header also emits sectionCountChanged() and
    sectionAutoResize().

    You can identify a section using the logicalIndex() and logicalIndexAt()
    functions, or by its index position, using the visualIndex() and visualIndexAt()
    functions. The visual index will change if a section is moved while the logical
    index wont change.

    For a horizontal header the section is equivalent to a column in the
    model, and for a vertical header the section is equivalent to a row
    in the model.

    \sa {Model/View Programming}, QListView, QTableView, QTreeView

*/

/*!
    \enum QHeaderView::ResizeMode

    \value Interactive Don't automatically change the size (let the
    user do it manually).
    \value Stretch Fill all the available visible space.
    \value Custom Don't automatically change the size here, leave it
    to some other object.
*/

/*!
    \fn void QHeaderView::sectionMoved(int logicalIndex, int oldVisualIndex, int newVisualIndex)

    This signal is emitted when a section is moved. The section's logical
    index is specified by \a logicalIndex, the old index by \a oldVisualIndex,
    and the new index position by \a newVisualIndex.

    \sa moveSection()
*/

/*!
    \fn void QHeaderView::sectionResized(int logicalIndex, int oldSize, int newSize)

    This signal is emitted when a section is resized. The section's logical
    number is specified by \a logicalIndex, the old size by \a oldSize, and the
    new size by \a newSize.

    \sa resizeSection
*/

/*!
    \fn void QHeaderView::sectionPressed(int logicalIndex)

    This signal is emitted when a section is pressed. The section's logical
    index is specified by \a logicalIndex.

    \sa setClickable()
*/

/*!
    \fn void QHeaderView::sectionClicked(int logicalIndex)

    This signal is emitted when a section is clicked. The section's logical
    index is specified by \a logicalIndex.

    Note that you will also get a sectionPressed

    \sa setClickable()
*/

/*!
    \fn void QHeaderView::sectionDoubleClicked(int logicalIndex)

    This signal is emitted when a section is double-clicked. The
    section's logical index is specified by \a logicalIndex.

    \sa setClickable()
*/

/*!
    \fn void QHeaderView::sectionCountChanged(int oldCount, int newCount)

    This signal is emitted when the number of sections changes; i.e.
    when sections are added or deleted. The original count is specified by
    \a oldCount, and the new count by \a newCount.

    \sa count(), length(), headerDataChanged()
*/

/*!
    \fn void QHeaderView::sectionHandleDoubleClicked(int logicalIndex)

    This signal is emitted when a section is double-clicked. The
    section's logical index is specified by \a logicalIndex.

    \sa setClickable()
*/

/*!
    \fn void QHeaderView::sectionAutoResize(int logicalIndex, QHeaderView::ResizeMode mode)

    This signal is emitted when a section is automatically resized.
    The section's logical index is specified by \a logicalIndex, and the
    resize mode by \a mode.

    \sa setResizeMode(), stretchLastSection()
*/

/*!
    \property QHeaderView::highlightSections
    \brief whether the sections containing selected items are highlighted
*/

/*!
    Creates a new generic header with the given \a orientation and \a parent.
*/
QHeaderView::QHeaderView(Qt::Orientation orientation, QWidget *parent)
    : QAbstractItemView(*new QHeaderViewPrivate, parent)
{
    Q_D(QHeaderView);
    d->orientation = orientation;
    d->defaultSectionSize = (orientation == Qt::Horizontal ? 100 : 30);
    d->defaultAlignment = (orientation == Qt::Horizontal
                           ? Qt::Alignment(Qt::AlignCenter) : Qt::AlignLeft|Qt::AlignVCenter);
    initialize();
}

/*!
  \internal
*/
QHeaderView::QHeaderView(QHeaderViewPrivate &dd,
                         Qt::Orientation orientation, QWidget *parent)
    : QAbstractItemView(dd, parent)
{
    Q_D(QHeaderView);
    d->orientation = orientation;
    d->defaultSectionSize = (orientation == Qt::Horizontal ? 100 : 30);
    d->defaultAlignment = (orientation == Qt::Horizontal
                           ? Qt::Alignment(Qt::AlignCenter) : Qt::AlignLeft|Qt::AlignVCenter);
    initialize();
}

/*!
  Destroys the header.
*/

QHeaderView::~QHeaderView()
{
}

/*!
  \internal
*/
void QHeaderView::initialize()
{
    Q_D(QHeaderView);
    setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    setFrameStyle(NoFrame);
    d->viewport->setMouseTracking(true);
    d->viewport->setBackgroundRole(QPalette::Button);
    delete d->delegate;
}

/*!
  \reimp
*/
void QHeaderView::setModel(QAbstractItemModel *model)
{
    Q_D(QHeaderView);
    if (d->model) {
        if (d->orientation == Qt::Horizontal) {
            QObject::disconnect(d->model, SIGNAL(columnsInserted(QModelIndex,int,int)),
                                this, SLOT(sectionsInserted(QModelIndex,int,int)));
            QObject::disconnect(d->model, SIGNAL(columnsAboutToBeRemoved(QModelIndex,int,int)),
                                this, SLOT(sectionsAboutToBeRemoved(QModelIndex,int,int)));
            QObject::disconnect(d->model, SIGNAL(columnsRemoved(QModelIndex,int,int)),
                                this, SLOT(_q_sectionsRemoved(QModelIndex,int,int)));
        } else {
            QObject::disconnect(d->model, SIGNAL(rowsInserted(QModelIndex,int,int)),
                                this, SLOT(sectionsInserted(QModelIndex,int,int)));
            QObject::disconnect(d->model, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)),
                                this, SLOT(sectionsAboutToBeRemoved(QModelIndex,int,int)));
            QObject::disconnect(d->model, SIGNAL(rowsRemoved(QModelIndex,int,int)),
                                this, SLOT(_q_sectionsRemoved(QModelIndex,int,int)));
         }
        QObject::disconnect(d->model, SIGNAL(headerDataChanged(Qt::Orientation,int,int)),
                            this, SLOT(headerDataChanged(Qt::Orientation,int,int)));
    }

    if (model) {
        if (d->orientation == Qt::Horizontal) {
            QObject::connect(model, SIGNAL(columnsInserted(QModelIndex,int,int)),
                             this, SLOT(sectionsInserted(QModelIndex,int,int)));
            QObject::connect(model, SIGNAL(columnsAboutToBeRemoved(QModelIndex,int,int)),
                this, SLOT(sectionsAboutToBeRemoved(QModelIndex,int,int)));
            QObject::connect(model, SIGNAL(columnsRemoved(QModelIndex,int,int)),
                this, SLOT(_q_sectionsRemoved(QModelIndex,int,int)));
        } else {
            QObject::connect(model, SIGNAL(rowsInserted(QModelIndex,int,int)),
                             this, SLOT(sectionsInserted(QModelIndex,int,int)));
            QObject::connect(model, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)),
                             this, SLOT(sectionsAboutToBeRemoved(QModelIndex,int,int)));
            QObject::connect(model, SIGNAL(rowsRemoved(QModelIndex,int,int)),
                             this, SLOT(_q_sectionsRemoved(QModelIndex,int,int)));
        }
        QObject::connect(model, SIGNAL(headerDataChanged(Qt::Orientation,int,int)),
                         this, SLOT(headerDataChanged(Qt::Orientation,int,int)));
    }
    d->clear();

    QAbstractItemView::setModel(model);
    // Users want to set sizes and modes before the widget is shown.
    // Thus, we have to initialize when the model is set,
    // and not lazily like we do in the other views.
    initializeSections();
}

/*!
  Returns the orientation of the header.

  \sa Qt::Orientation
*/

Qt::Orientation QHeaderView::orientation() const
{
    Q_D(const QHeaderView);
    return d->orientation;
}

/*!
    Returns the offset of the header: this is the header's left-most
    (or top-most for vertical headers) visible pixel.

    \sa setOffset()
*/

int QHeaderView::offset() const
{
    Q_D(const QHeaderView);
    return d->offset;
}

/*!
    \fn void QHeaderView::setOffset(int offset)

    Sets the header's offset to \a offset.

    \sa offset(), length()
*/

void QHeaderView::setOffset(int newOffset)
{
    Q_D(QHeaderView);
    if (d->offset == newOffset)
        return;

    int ndelta = d->offset - newOffset;
    d->offset = newOffset;
    if (d->orientation == Qt::Horizontal)
        d->viewport->scroll(isRightToLeft() ? -ndelta : ndelta, 0);
    else
        d->viewport->scroll(0, ndelta);
}

/*!
  Returns the length along the orientation of the header.

  \sa sizeHint(), setResizeMode(), offset()
*/

int QHeaderView::length() const
{
    Q_D(const QHeaderView);
    if (d->sections.count())
        return d->sections.last().position;
    return 0;
}

/*!
    Returns a suitable size hint for this header.

    \sa sectionSizeHint()
*/

QSize QHeaderView::sizeHint() const
{
    Q_D(const QHeaderView);
    if (d->model == 0 || count() < 1)
        return QSize(0, 0);
    if (d->cachedSizeHint.isValid())
        return d->cachedSizeHint;
    int width = 0;
    int height = 0;
    // get size hint for the first n sections
    int c = qMin(count(), 100);
    for (int i = 0; i < c; ++i) {
        QSize hint = sectionSizeFromContents(i);
        width = qMax(hint.width(), width);
        height = qMax(hint.height(), height);
    }
    // get size hint for the last n sections
    c = qMax(count() - 100, c);
    for (int j = count() - 1; j >= c; --j) {
        QSize hint = sectionSizeFromContents(j);
        width = qMax(hint.width(), width);
        height = qMax(hint.height(), height);
    }
    d->cachedSizeHint = QSize(width, height);
    return d->cachedSizeHint;
}

/*!
    Returns a suitable size hint for the section specified by \a logicalIndex.

    \sa sizeHint(), defaultSectionSize()
*/

int QHeaderView::sectionSizeHint(int logicalIndex) const
{
    Q_D(const QHeaderView);
    if (d->model == 0 || logicalIndex < 0 || logicalIndex >= count())
        return -1;
    QSize size = sectionSizeFromContents(logicalIndex);
    return orientation() == Qt::Horizontal ? size.width() : size.height();
}

/*!
    Returns the visual index of the section that covers the given \a position in the viewport.

    \sa logicalIndexAt()
*/

int QHeaderView::visualIndexAt(int position) const
{
    Q_D(const QHeaderView);
    d->executePostedLayout();
    int count = this->count();
    if (count < 1)
        return -1;
    if (d->reverse())
        position = d->viewport->width() - position;
    position += d->offset;
    if (position < 0 || position > length())
        return -1;

    int start = 0;
    int end = count - 1;
    int visual = (end + 1) / 2;

    const QVector<QHeaderViewPrivate::HeaderSection> sections = d->sections;
    while (end - start > 0) {
        if (sections.at(visual).position > position)
            end = visual - 1;
        else
            start = visual;
        visual = (start + end + 1) / 2;
    }