qtreewidgetitemiterator.cpp

奇趣公司比较新的qt/emd版本

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#include <private/qtreewidgetitemiterator_p.h>
#include "qtreewidget.h"
#include "qtreewidget_p.h"
#include "qwidgetitemdata_p.h"

#ifndef QT_NO_TREEWIDGET

/*!
  \class QTreeWidgetItemIterator
  \ingroup model-view
  \brief The QTreeWidgetItemIterator class provides a way to iterate over the 
  items in a QTreeWidget instance.

  The iterator will walk the items in a pre-order traversal order, thus visiting the
  parent node \e before it continues to the child nodes.

  For example, the following code examples each item in a tree, checking the
  text in the first column against a user-specified search string:

  \quotefromfile snippets/qtreewidgetitemiterator-using/mainwindow.cpp
  \skipto findItems(
  \skipto QTreeWidgetItemIterator
  \printuntil }

  It is also possible to filter out certain types of node by passing certain
  \l{IteratorFlag}{flags} to the constructor of QTreeWidgetItemIterator.

  \sa QTreeWidget, {Model/View Programming}, QTreeWidgetItem
*/

/*!
    Constructs an iterator for the same QTreeWidget as \a it. The
    current iterator item is set to point on the current item of \a it.
*/

QTreeWidgetItemIterator::QTreeWidgetItemIterator(const QTreeWidgetItemIterator &it)
    :  d_ptr(new QTreeWidgetItemIteratorPrivate(*(it.d_ptr))),
    current(it.current), flags(it.flags)
{
    Q_D(QTreeWidgetItemIterator);
    Q_ASSERT(d->m_model);
    d->m_model->iterators.append(this);
}

/*!
    Constructs an iterator for the given \a widget that uses the specified \a flags
    to determine which items are found during iteration.
    The iterator is set to point to the first top-level item contained in the widget,
    or the next matching item if the top-level item doesn't match the flags.

    \sa QTreeWidgetItemIterator::IteratorFlag
*/

QTreeWidgetItemIterator::QTreeWidgetItemIterator(QTreeWidget *widget, IteratorFlags flags)
: current(0), flags(flags)
{
    Q_ASSERT(widget);
    QTreeModel *model = qobject_cast<QTreeModel*>(widget->model());
    Q_ASSERT(model);
    d_ptr = new QTreeWidgetItemIteratorPrivate(this, model);
    model->iterators.append(this);
    if (!model->rootItem->children.isEmpty()) current = model->rootItem->children.first();
    if (current && !matchesFlags(current))
        ++(*this);
}

/*!
    Constructs an iterator for the given \a item that uses the specified \a flags
    to determine which items are found during iteration.
    The iterator is set to point to \a item, or the next matching item if \a item
    doesn't match the flags.

    \sa QTreeWidgetItemIterator::IteratorFlag
*/

QTreeWidgetItemIterator::QTreeWidgetItemIterator(QTreeWidgetItem *item, IteratorFlags flags)
    : d_ptr(new QTreeWidgetItemIteratorPrivate(
                this, ::qobject_cast<QTreeModel*>(item->view->model()))),
      current(item), flags(flags)
{
    Q_D(QTreeWidgetItemIterator);
    Q_ASSERT(item);
    QTreeModel *model = ::qobject_cast<QTreeModel*>(item->view->model());
    Q_ASSERT(model);
    model->iterators.append(this);

    // Initialize m_currentIndex and m_parentIndex as it would be if we had traversed from
    // the beginning.
    QTreeWidgetItem *parent = item;
    parent = parent->parent();
    QList<QTreeWidgetItem *> children = parent ? parent->children : d->m_model->rootItem->children;
    d->m_currentIndex = children.indexOf(item);

    while (parent) {
        QTreeWidgetItem *itm = parent;
        parent = parent->parent();
        QList<QTreeWidgetItem *> children = parent ? parent->children : d->m_model->rootItem->children;
        int index = children.indexOf(itm);
        d->m_parentIndex.prepend(index);
    }

    if (current && !matchesFlags(current))
        ++(*this);
}

/*!
    Destroys the iterator.
*/

QTreeWidgetItemIterator::~QTreeWidgetItemIterator()
{
    d_func()->m_model->iterators.removeAll(this);
    delete d_ptr;
}

/*!
    Assignment. Makes a copy of \a it and returns a reference to its
    iterator.
*/

QTreeWidgetItemIterator &QTreeWidgetItemIterator::operator=(const QTreeWidgetItemIterator &it)
{
    Q_D(QTreeWidgetItemIterator);
    if (d_func()->m_model != it.d_func()->m_model) {
        d_func()->m_model->iterators.removeAll(this);
        it.d_func()->m_model->iterators.append(this);
    }
    current = it.current;
    flags = it.flags;
    d->operator=(*it.d_func());
    return *this;
}

/*!
    The prefix ++ operator (++it) advances the iterator to the next matching item 
    and returns a reference to the resulting iterator.
    Sets the current pointer to 0 if the current item is the last matching item.
*/

QTreeWidgetItemIterator &QTreeWidgetItemIterator::operator++()
{
    if (current)
        do {
            current = d_func()->next(current);
        } while (current && !matchesFlags(current));
    return *this;
}

/*!
    The prefix -- operator (--it) advances the iterator to the previous matching item 
    and returns a reference to the resulting iterator.
    Sets the current pointer to 0 if the current item is the first matching item.
*/

QTreeWidgetItemIterator &QTreeWidgetItemIterator::operator--()
{
    if (current)
        do {
            current = d_func()->previous(current);
        } while (current && !matchesFlags(current));
    return *this;
}

/*!
  \internal
*/
bool QTreeWidgetItemIterator::matchesFlags(const QTreeWidgetItem *item) const
{
    if (!item)
        return false;

    if (flags == All)
        return true;

    {
        Qt::ItemFlags itemFlags = item->flags();
        if ((flags & Selectable) && !(itemFlags & Qt::ItemIsSelectable))
            return false;
        if ((flags & NotSelectable) && (itemFlags & Qt::ItemIsSelectable))
            return false;
        if ((flags & DragEnabled) && !(itemFlags & Qt::ItemIsDragEnabled))
            return false;
        if ((flags & DragDisabled) && (itemFlags & Qt::ItemIsDragEnabled))
            return false;
        if ((flags & DropEnabled) && !(itemFlags & Qt::ItemIsDropEnabled))
            return false;
        if ((flags & DropDisabled) && (itemFlags & Qt::ItemIsDropEnabled))
            return false;
        if ((flags & Enabled) && !(itemFlags & Qt::ItemIsEnabled))
            return false;
        if ((flags & Disabled) && (itemFlags & Qt::ItemIsEnabled))
            return false;
        if ((flags & Editable) && !(itemFlags & Qt::ItemIsEditable))
            return false;