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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>

QT_BEGIN_NAMESPACE

/*!

    \class QTreeView

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

    \ingroup model-view

    \ingroup advanced

    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:

    \snippet doc/src/snippets/shareddirmodel/main.cpp 3

    \snippet doc/src/snippets/shareddirmodel/main.cpp 6

    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 \c{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. If this value is set to true, this property will override the

    resize mode set on the last section in the 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 Up   \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 Down \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 Left  \o Hides the children of the current item (if present)

         by collapsing a branch.

    \row \o Minus  \o Same as LeftArrow.

    \row \o Right \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 tree 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 (model == d->model)

        return;

    if (d->model && d->model != QAbstractItemModelPrivate::staticEmptyModel()) {

        disconnect(d->model, SIGNAL(rowsRemoved(QModelIndex,int,int)),

                this, SLOT(rowsRemoved(QModelIndex,int,int)));

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

    }

    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(modelAboutToBeReset()), SLOT(_q_modelAboutToBeReset()));

    if (d->sortingEnabled)

        d->_q_sortIndicatorChanged(header()->sortIndicatorSection(), header()->sortIndicatorOrder());

}

/*!

  \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) {

        // support row editing

        disconnect(d->selectionModel, SIGNAL(currentRowChanged(QModelIndex,QModelIndex)),

                   d->model, SLOT(submit()));

    }

    d->header->setSelectionModel(selectionModel);

    QAbstractItemView::setSelectionModel(selectionModel);

    if (d->selectionModel) {

        // 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.

  By default, this property has a value of -1, meaning that auto-expansion is disabled.

*/

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.

  By default, this property has a value of 20.

*/

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();

    }

}

/*!

  \property QTreeView::uniformRowHeights

  \brief whether all items in the treeview have the same height

  This property should only be set to true if it is guaranteed that all items

  in the view has the same height. This enables the view to do some

  optimizations.

  The height is obtained from the first item in the view.  It is updated

  when the data changes on that item.

  By default, this property is false.

*/

bool QTreeView::uniformRowHeights() const

{

    Q_D(const QTreeView);

    return d->uniformRowHeights;

}

void QTreeView::setUniformRowHeights(bool uniform)

{

    Q_D(QTreeView);

    d->uniformRowHeights = uniform;

}

/*!

  \property QTreeView::itemsExpandable

  \brief whether the items are expandable by the user.

  This property holds whether the user can expand and collapse items

  interactively.

  By default, this property is true.

*/

bool QTreeView::itemsExpandable() const

{

    Q_D(const QTreeView);

    return d->itemsExpandable;

}

void QTreeView::setItemsExpandable(bool enable)

{

    Q_D(QTreeView);

    d->itemsExpandable = enable;

}

/*!

  \property QTreeView::expandsOnDoubleClick

  \since 4.4

  \brief whether the items can be expanded by double-clicking.

  This property holds whether the user can expand and collapse items

  by double-clicking. The default value is true.

  \sa itemsExpandable

*/

bool QTreeView::expandsOnDoubleClick() const

{

    Q_D(const QTreeView);

    return d->expandsOnDoubleClick;

}

void QTreeView::setExpandsOnDoubleClick(bool enable)

{

    Q_D(QTreeView);

    d->expandsOnDoubleClick = enable;

}

/*!

  Returns the horizontal position of the \a column in the viewport.

*/

int QTreeView::columnViewportPosition(int column) const

{

    Q_D(const QTreeView);

    return d->header->sectionViewportPosition(column);

}

/*!

  Returns the width of the \a column.

  \sa resizeColumnToContents(), setColumnWidth()

*/

int QTreeView::columnWidth(int column) const

{

    Q_D(const QTreeView);

    return d->header->sectionSize(column);

}

/*!

  \since 4.2

  Sets the width of the given \a column to the \a width specified.

  \sa columnWidth(), resizeColumnToContents()

*/

void QTreeView::setColumnWidth(int column, int width)

{

    Q_D(QTreeView);

    d->header->resizeSection(column, width);

}

/*!

  Returns the column in the tree view whose header covers the \a x

  coordinate given.

*/

int QTreeView::columnAt(int x) const

{

    Q_D(const QTreeView);

    return d->header->logicalIndexAt(x);

}

/*!

    Returns true if the \a column is hidden; otherwise returns false.

    \sa hideColumn(), isRowHidden()

*/