qcolumnview.cpp

奇趣公司比较新的qt/emd版本

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#include <qglobal.h>

#ifndef QT_NO_COLUMNVIEW

#include "qcolumnview.h"
#include "qcolumnview_p.h"
#include "qcolumnviewgrip_p.h"

#include <qlistview.h>
#include <qabstractitemdelegate.h>
#include <qscrollbar.h>
#include <qpainter.h>
#include <qdebug.h>
#include <qpainterpath.h>

#define ANIMATION_DURATION_MSEC 150

/*!
    \since 4.3
    \class QColumnView
    \brief The QColumnView class provides a model/view implementation of a column view.
    \ingroup model-view
    \mainclass

    QColumnView displays a model in a number of QListViews, one for each
    hierarchy in the tree.  This is sometimes referred to as a cascading list.

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

    QColumnView implements the interfaces defined by the
    QAbstractItemView class to allow it to display data provided by
    models derived from the QAbstractItemModel class.

    \image qcolumnview.png

    \sa \link model-view-programming.html Model/View Programming\endlink
*/

/*!
    Constructs a column view with a \a parent to represent a model's
    data. Use setModel() to set the model.

    \sa QAbstractItemModel
*/
QColumnView::QColumnView(QWidget * parent)
:  QAbstractItemView(*new QColumnViewPrivate, parent)
{
    Q_D(QColumnView);
    d->initialize();
}

/*!
    \internal
*/
QColumnView::QColumnView(QColumnViewPrivate & dd, QWidget * parent)
:  QAbstractItemView(dd, parent)
{
    Q_D(QColumnView);
    d->initialize();
}

void QColumnViewPrivate::initialize()
{
    Q_Q(QColumnView);
    q->setTextElideMode(Qt::ElideMiddle);
    q->connect(&currentAnimation, SIGNAL(frameChanged(int)),
            q->horizontalScrollBar(), SLOT(setValue(int)));
    q->connect(&currentAnimation, SIGNAL(finished()), q, SLOT(_q_changeCurrentColumn()));
    delete itemDelegate;
    q->setItemDelegate(new QColumnViewDelegate(q));
}

/*!
    Destroys the column view.
*/
QColumnView::~QColumnView()
{
}

/*!
    \property QColumnView::resizeGripsVisible
    \brief the way to specify if the list views gets resize grips or not

    By default, \c visible is set to true

    \sa setRootIndex()
*/
void QColumnView::setResizeGripsVisible(bool visible)
{
    Q_D(QColumnView);
    if (d->showResizeGrips == visible)
        return;
    d->showResizeGrips = visible;
    for (int i = 0; i < d->columns.count(); ++i) {
        QAbstractItemView *view = d->columns[i];
        if (visible) {
            QColumnViewGrip *grip = new QColumnViewGrip(view);
            view->setCornerWidget(grip);
            connect(grip, SIGNAL(gripMoved(int)), this, SLOT(_q_gripMoved(int)));
        } else {
            QWidget *widget = view->cornerWidget();
            view->setCornerWidget(0);
            widget->deleteLater();
        }
    }
}

bool QColumnView::resizeGripsVisible() const
{
    Q_D(const QColumnView);
    return d->showResizeGrips;
}

/*!
    \reimp
*/
void QColumnView::setModel(QAbstractItemModel *model)
{
    Q_D(QColumnView);
    d->closeColumns();
    QAbstractItemView::setModel(model);
}

/*!
    \reimp
*/
void QColumnView::setRootIndex(const QModelIndex &index)
{
    Q_D(QColumnView);
    if (!model())
        return;

    d->closeColumns();
    Q_ASSERT(d->columns.count() == 0);

    QAbstractItemView *view = d->createColumn(index, true);
    view->selectionModel()->deleteLater();
    view->setSelectionModel(selectionModel());

    QAbstractItemView::setRootIndex(index);
    d->updateScrollbars();
}

/*!
    \reimp
*/
bool QColumnView::isIndexHidden(const QModelIndex &index) const
{
    Q_UNUSED(index);
    return false;
}

/*!
    \reimp
*/
QModelIndex QColumnView::indexAt(const QPoint &point) const
{
    Q_D(const QColumnView);
    for (int i = 0; i < d->columns.size(); ++i) {
        QPoint topLeft = d->columns.at(i)->frameGeometry().topLeft();
        QPoint adjustedPoint(point.x() - topLeft.x(), point.y() - topLeft.y());
        QModelIndex index = d->columns.at(i)->indexAt(adjustedPoint);
        if (index.isValid())
            return index;
    }
    return QModelIndex();
}

/*!
    \reimp
*/
QRect QColumnView::visualRect(const QModelIndex &index) const
{
    if (!index.isValid())
        return QRect();

    Q_D(const QColumnView);
    for (int i = 0; i < d->columns.size(); ++i) {
        QRect rect = d->columns.at(i)->visualRect(index);
        if (!rect.isNull()) {
            rect.translate(d->columns.at(i)->frameGeometry().topLeft());
            return rect;
        }
    }
    return QRect();
}

/*!
    \reimp
 */
void QColumnView::scrollContentsBy(int dx, int dy)
{
    Q_D(QColumnView);
    if (d->columns.isEmpty() || dx == 0)
        return;

    dx = isRightToLeft() ? -dx : dx;
    for (int i = 0; i < d->columns.count(); ++i)
        d->columns.at(i)->move(d->columns.at(i)->x() + dx, 0);
    d->offset += dx;
    QAbstractItemView::scrollContentsBy(dx, dy);
}

/*!
    \reimp
*/
void QColumnView::scrollTo(const QModelIndex &index, ScrollHint hint)
{
    Q_D(QColumnView);
    Q_UNUSED(hint);
    if (!index.isValid() || d->columns.isEmpty())
        return;

    if (d->currentAnimation.state() == QTimeLine::Running)
        return;

    d->currentAnimation.stop();

    // Fill up what is needed to get to index
    d->closeColumns(index, true);

    QModelIndex indexParent = index.parent();
    // Find the left edge of the column that contains index
    int currentColumn = 0;
    int leftEdge = 0;
    while (currentColumn < d->columns.size()) {
        if (indexParent == d->columns.at(currentColumn)->rootIndex())
            break;
        leftEdge += d->columns.at(currentColumn)->width();
        ++currentColumn;
    }

    // Don't let us scroll above the root index
    if (currentColumn == d->columns.size())
        return;

    int indexColumn = currentColumn;
    // Find the width of what we want to show (i.e. the right edge)
    int visibleWidth = d->columns.at(currentColumn)->width();
    // We want to always try to show two columns
    if (currentColumn + 1 < d->columns.size()) {
        ++currentColumn;
        visibleWidth += d->columns.at(currentColumn)->width();
    }

    int rightEdge = leftEdge + visibleWidth;
    if (isRightToLeft()) {
        leftEdge = viewport()->width() - leftEdge;
        rightEdge = leftEdge - visibleWidth;
        qSwap(rightEdge, leftEdge);
    }

    // If it is already visible don't animate
    if (leftEdge > -horizontalOffset()
        && rightEdge <= ( -horizontalOffset() + viewport()->size().width())) {
            d->columns.at(indexColumn)->scrollTo(index);
            d->_q_changeCurrentColumn();
            return;
    }

    int newScrollbarValue = 0;
    if (isRightToLeft()) {
        if (leftEdge < 0) {
            // scroll to the right
            newScrollbarValue = viewport()->size().width() - leftEdge;
        } else {
            // scroll to the left
            newScrollbarValue = rightEdge + horizontalOffset();
        }
    } else {
        if (leftEdge > -horizontalOffset()) {
            // scroll to the right
            newScrollbarValue = rightEdge - viewport()->size().width();
        } else {
            // scroll to the left
            newScrollbarValue = leftEdge;
        }
    }

    //horizontalScrollBar()->setValue(newScrollbarValue);
    //d->_q_changeCurrentColumn();
    //return;
    // or do the following currentAnimation

    int oldValue = horizontalScrollBar()->value();

    if (oldValue < newScrollbarValue) {
        d->currentAnimation.setFrameRange(oldValue, newScrollbarValue);
        d->currentAnimation.setDirection(QTimeLine::Forward);
        d->currentAnimation.setCurrentTime(0);
    } else {
        d->currentAnimation.setFrameRange(newScrollbarValue, oldValue);
        d->currentAnimation.setDirection(QTimeLine::Backward);
    }
    d->currentAnimation.start();
}

/*!
    \reimp
    Move left should go to the parent index
    Move right should go to the child index or down if there is no child
*/
QModelIndex QColumnView::moveCursor(CursorAction cursorAction, Qt::KeyboardModifiers modifiers)
{
    // the child views which have focus get to deal with this first and if
    // they don't accept it then it comes up this this view and we only grip left/right
    Q_UNUSED(modifiers);
    if (!model())
        return QModelIndex();

    QModelIndex current = currentIndex();
    if (isRightToLeft()) {
        if (cursorAction == MoveLeft)
            cursorAction = MoveRight;
        else if (cursorAction == MoveRight)
            cursorAction = MoveLeft;
    }
    switch (cursorAction) {
    case MoveLeft:
        if (current.parent().isValid() && current.parent() != rootIndex())
            return (current.parent());
        else
            return current;
        break;

    case MoveRight:
        if (model()->hasChildren(current))
            return model()->index(0, 0, current);
        else
            return current.sibling(current.row() + 1, current.column());
        break;