qtreeview.cpp

奇趣公司比较新的qt/emd版本

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#include "qtreeview.h"

#ifndef QT_NO_TREEVIEW
#include <qheaderview.h>
#include <qitemdelegate.h>
#include <qapplication.h>
#include <qscrollbar.h>
#include <qpainter.h>
#include <qstack.h>
#include <qstyle.h>
#include <qstyleoption.h>
#include <qevent.h>
#include <qpen.h>
#include <qdebug.h>
#ifndef QT_NO_ACCESSIBILITY
#include <qaccessible.h>
#endif

#include <private/qtreeview_p.h>

/*!
    \class QTreeView
    \brief The QTreeView class provides a default model/view implementation of a tree view.

    \ingroup model-view
    \mainclass

    A QTreeView implements a tree representation of items from a
    model. This class is used to provide standard hierarchical lists that
    were previously provided by the \c QListView class, but using the more
    flexible approach provided by Qt's model/view architecture.

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

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

    It is simple to construct a tree view displaying data from a
    model. In the following example, the contents of a directory are
    supplied by a QDirModel and displayed as a tree:

    \quotefromfile snippets/shareddirmodel/main.cpp
    \skipto QDirModel *model
    \printuntil QTreeView *tree
    \skipto tree->setModel(
    \printuntil tree->setModel(

    The model/view architecture ensures that the contents of the tree view
    are updated as the model changes.

    Items that have children can be in an expanded (children are
    visible) or collapsed (children are hidden) state. When this state
    changes a collapsed() or expanded() signal is emitted with the
    model index of the relevant item.

    The amount of indentation used to indicate levels of hierarchy is
    controlled by the \l indentation property.

    Headers in tree views are constructed using the QHeaderView class
    and can be hidden using header()->hide(). Note that each header
    is configured with its \l{QHeaderView::}{stretchLastSection}
    property set to true, ensuring that the view does not waste any
    of the space assigned to it for its header.

    \section1 Key Bindings

    QTreeView supports a set of key bindings that enable the user to
    navigate in the view and interact with the contents of items:

    \table
    \header \o Key \o Action
    \row \o UpArrow   \o Moves the cursor to the item in the same column on
         the previous row. If the parent of the current item has no more rows to
         navigate to, the cursor moves to the relevant item in the last row
         of the sibling that precedes the parent.
    \row \o DownArrow \o Moves the cursor to the item in the same column on
         the next row. If the parent of the current item has no more rows to
         navigate to, the cursor moves to the relevant item in the first row
         of the sibling that follows the parent.
    \row \o LeftArrow  \o Hides the children of the current item (if present)
         by collapsing a branch.
    \row \o Minus  \o Same as LeftArrow.
    \row \o RightArrow \o Reveals the children of the current item (if present)
         by expanding a branch.
    \row \o Plus  \o Same as RightArrow.
    \row \o Asterisk  \o Expands all children of the current item (if present).
    \row \o PageUp   \o Moves the cursor up one page.
    \row \o PageDown \o Moves the cursor down one page.
    \row \o Home \o Moves the cursor to an item in the same column of the first
         row of the first top-level item in the model.
    \row \o End  \o Moves the cursor to an item in the same column of the last
         row of the last top-level item in the model.
    \row \o F2   \o In editable models, this opens the current item for editing.
         The Escape key can be used to cancel the editing process and revert
         any changes to the data displayed.
    \endtable

    \omit
    Describe the expanding/collapsing concept if not covered elsewhere.
    \endomit

    \table 100%
    \row \o \inlineimage windowsxp-treeview.png Screenshot of a Windows XP style tree view
         \o \inlineimage macintosh-treeview.png Screenshot of a Macintosh style tree view
         \o \inlineimage plastique-treeview.png Screenshot of a Plastique style tree view
    \row \o A \l{Windows XP Style Widget Gallery}{Windows XP style} tree view.
         \o A \l{Macintosh Style Widget Gallery}{Macintosh style} tree view.
         \o A \l{Plastique Style Widget Gallery}{Plastique style} tree view.
    \endtable

    \section1 Improving Performance

    It is possible to give the view hints about the data it is handling in order
    to improve its performance when displaying large numbers of items. One approach
    that can be taken for views that are intended to display items with equal heights
    is to set the \l uniformRowHeights property to true.

    \sa QListView, QTreeWidget, {View Classes}, QAbstractItemModel, QAbstractItemView,
        {Dir View Example}
*/


/*!
  \fn void QTreeView::expanded(const QModelIndex &index)

  This signal is emitted when the item specified by \a index is expanded.
*/


/*!
  \fn void QTreeView::collapsed(const QModelIndex &index)

  This signal is emitted when the item specified by \a index is collapsed.
*/

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

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

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

/*!
  Destroys the tree view.
*/
QTreeView::~QTreeView()
{
}

/*!
  \reimp
*/
void QTreeView::setModel(QAbstractItemModel *model)
{
    Q_D(QTreeView);
    if (d->selectionModel) { // support row editing
        disconnect(d->selectionModel, SIGNAL(currentRowChanged(QModelIndex,QModelIndex)),
                   d->model, SLOT(submit()));
        disconnect(d->model, SIGNAL(rowsRemoved(QModelIndex,int,int)),
                   this, SLOT(rowsRemoved(QModelIndex,int,int)));
        disconnect(d->model, SIGNAL(modelAboutToBeReset()), this, SLOT(_q_modelAboutToBeReset()));
    }
    d->viewItems.clear();
    d->expandedIndexes.clear();
    d->hiddenIndexes.clear();
    d->header->setModel(model);
    QAbstractItemView::setModel(model);

    // QAbstractItemView connects to a private slot
    disconnect(d->model, SIGNAL(rowsRemoved(QModelIndex,int,int)),
               this, SLOT(_q_rowsRemoved(QModelIndex,int,int)));
    // do header layout after the tree
    disconnect(d->model, SIGNAL(layoutChanged()),
               d->header, SLOT(_q_layoutChanged()));
    // QTreeView has a public slot for this
    connect(d->model, SIGNAL(rowsRemoved(QModelIndex,int,int)),
            this, SLOT(rowsRemoved(QModelIndex,int,int)));

    connect(d->model, SIGNAL(columnsAboutToBeRemoved(QModelIndex,int,int)),
            this, SLOT(_q_columnsAboutToBeRemoved(QModelIndex,int,int)));
    connect(d->model, SIGNAL(columnsRemoved(QModelIndex,int,int)),
            this, SLOT(_q_columnsRemoved(QModelIndex,int,int)));

    connect(d->model, SIGNAL(modelAboutToBeReset()), SLOT(_q_modelAboutToBeReset()));

    if (d->sortingEnabled)
        sortByColumn(header()->sortIndicatorSection());
}

/*!
  \reimp
*/
void QTreeView::setRootIndex(const QModelIndex &index)
{
    Q_D(QTreeView);
    d->header->setRootIndex(index);
    QAbstractItemView::setRootIndex(index);
}

/*!
  \reimp
*/
void QTreeView::setSelectionModel(QItemSelectionModel *selectionModel)
{
    Q_D(QTreeView);
    Q_ASSERT(selectionModel);
    if (d->selectionModel) {
        if (d->allColumnsShowFocus) {
            QObject::disconnect(d->selectionModel, SIGNAL(currentChanged(QModelIndex,QModelIndex)),
                                this, SLOT(_q_currentChanged(QModelIndex,QModelIndex)));
        }
        // support row editing
        disconnect(d->selectionModel, SIGNAL(currentRowChanged(QModelIndex,QModelIndex)),
                   d->model, SLOT(submit()));
    }

    d->header->setSelectionModel(selectionModel);
    QAbstractItemView::setSelectionModel(selectionModel);

    if (d->selectionModel) {
        if (d->allColumnsShowFocus) {
            QObject::connect(d->selectionModel, SIGNAL(currentChanged(QModelIndex,QModelIndex)),
                             this, SLOT(_q_currentChanged(QModelIndex,QModelIndex)));
        }
        // support row editing
        connect(d->selectionModel, SIGNAL(currentRowChanged(QModelIndex,QModelIndex)),
                d->model, SLOT(submit()));
    }
}

/*!
  Returns the header for the tree view.

  \sa QAbstractItemModel::headerData()
*/
QHeaderView *QTreeView::header() const
{
    Q_D(const QTreeView);
    return d->header;
}

/*!
    Sets the header for the tree view, to the given \a header.

    The view takes ownership over the given \a header and deletes it
    when a new header is set.

    \sa QAbstractItemModel::headerData()
*/
void QTreeView::setHeader(QHeaderView *header)
{
    Q_D(QTreeView);
    if (header == d->header || !header)
        return;
    if (d->header && d->header->parent() == this)
        delete d->header;
    d->header = header;
    d->header->setParent(this);

    if (!d->header->model()) {
        d->header->setModel(d->model);
        if (d->selectionModel)
            d->header->setSelectionModel(d->selectionModel);
    }

    connect(d->header, SIGNAL(sectionResized(int,int,int)),
            this, SLOT(columnResized(int,int,int)));
    connect(d->header, SIGNAL(sectionMoved(int,int,int)),
            this, SLOT(columnMoved()));
    connect(d->header, SIGNAL(sectionCountChanged(int,int)),
            this, SLOT(columnCountChanged(int,int)));
    connect(d->header, SIGNAL(sectionHandleDoubleClicked(int)),
            this, SLOT(resizeColumnToContents(int)));
    connect(d->header, SIGNAL(geometriesChanged()),
            this, SLOT(updateGeometries()));

    setSortingEnabled(d->sortingEnabled);
}

/*!
  \property QTreeView::autoExpandDelay
  \brief The delay time before items in a tree are opened during a drag and drop operation.
  \since 4.3

  This property holds the amount of time in milliseconds that the user must wait over
  a node before that node will automatically open or close.  If the time is
  set to less then 0 then it will not be activated.
*/
int QTreeView::autoExpandDelay() const
{
    Q_D(const QTreeView);
    return d->autoExpandDelay;
}

void QTreeView::setAutoExpandDelay(int delay)
{
    Q_D(QTreeView);
    d->autoExpandDelay = delay;
}

/*!
  \property QTreeView::indentation
  \brief indentation of the items in the tree view.

  This property holds the indentation measured in pixels of the items for each
  level in the tree view. For top-level items, the indentation specifies the
  horizontal distance from the viewport edge to the items in the first column;
  for child items, it specifies their indentation from their parent items.
*/
int QTreeView::indentation() const
{
    Q_D(const QTreeView);
    return d->indent;
}

void QTreeView::setIndentation(int i)
{
    Q_D(QTreeView);
    if (i != d->indent) {
        d->indent = i;
        d->viewport->update();
    }
}

/*!
  \property QTreeView::rootIsDecorated
  \brief whether to show controls for expanding and collapsing top-level items

  Items with children are typically shown with controls to expand and collapse
  them, allowing their children to be shown or hidden. If this property is
  false, these controls are not shown for top-level items. This can be used to
  make a single level tree structure appear like a simple list of items.

  By default, this property is true.
*/
bool QTreeView::rootIsDecorated() const
{
    Q_D(const QTreeView);
    return d->rootDecoration;
}

void QTreeView::setRootIsDecorated(bool show)
{
    Q_D(QTreeView);
    if (show != d->rootDecoration) {
        d->rootDecoration = show;
        d->viewport->update();
    }