/*=========================================================================

   Program: ParaView
   Module:    $RCSfile: pqTreeWidgetItem.h,v $

   Copyright (c) 2005,2006 Sandia Corporation, Kitware Inc.
   All rights reserved.

   ParaView is a free software; you can redistribute it and/or modify it
   under the terms of the ParaView license version 1.2. 
   
   See License_v1.2.txt for the full ParaView license.
   A copy of this license can be obtained by contacting
   Kitware Inc.
   28 Corporate Drive
   Clifton Park, NY 12065
   USA

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

========================================================================*/
#ifndef __pqTreeWidgetItem_h 
#define __pqTreeWidgetItem_h

#include "QtWidgetsExport.h"
#include <QTreeWidgetItem>

/// pqTreeWidgetItem is a QTreeWidgetItem with callbacks for whenever the data
/// for the pqTreeWidgetItem changes. This is designed as a replacement for
/// pqTreeWidgetItemObject avoid the need for pqTreeWidgetItem to be a QObject
/// subclass, thus keeping them light-weight.
class QTWIDGETS_EXPORT pqTreeWidgetItem : public QTreeWidgetItem
{
  typedef QTreeWidgetItem Superclass;
public:
  pqTreeWidgetItem(int atype=UserType):
    Superclass(atype), CallbackHandler(0) { }
  pqTreeWidgetItem(const QStringList& strings, int atype=UserType):
    Superclass(strings, atype), CallbackHandler(0) { }
  pqTreeWidgetItem(QTreeWidget *aparent, int atype=UserType):
    Superclass(aparent, atype), CallbackHandler(0) { }
  pqTreeWidgetItem(QTreeWidget *aparent, const QStringList &strings, int atype=UserType):
    Superclass(aparent, strings, atype), CallbackHandler(0) { }
  pqTreeWidgetItem(QTreeWidget *aparent, QTreeWidgetItem *preceding, int atype=UserType):
    Superclass(aparent, preceding, atype), CallbackHandler(0) { }
  pqTreeWidgetItem(QTreeWidgetItem *aparent, int atype=UserType):
    Superclass(aparent, atype), CallbackHandler(0) { }
  pqTreeWidgetItem(QTreeWidgetItem *aparent, const QStringList& strings, int atype=UserType):
    Superclass(aparent, strings, atype), CallbackHandler(0) { }
  pqTreeWidgetItem(QTreeWidgetItem *aparent, QTreeWidgetItem* preceding, int atype=UserType):
    Superclass(aparent, preceding, atype), CallbackHandler(0) { }

  /// overload setData() to call callbacks if set.
  virtual void setData(int column, int role, const QVariant& v);

public:
  class pqCallbackHandler
    {
  public:
    virtual ~pqCallbackHandler() {};

    /// Called to indicate that the data is about to be changed.
    virtual void dataAboutToChange(
      pqTreeWidgetItem* /*item*/, int /*column*/, int /*role*/) {};

    /// Called to indicate that the data is about to be changed.
    virtual void checkStateAboutToChange(
      pqTreeWidgetItem* /*item*/, int /*column*/) {};

    /// Called to indicate that the check state for the item has been changed.
    virtual void checkStateChanged(pqTreeWidgetItem* /*item*/, int /*column*/) {};

    /// Called to indicate that the data has been changed.
    virtual void dataChanged(
      pqTreeWidgetItem* /*item*/, int /*column*/, int /*role*/) {};

    /// Called to check if the change has to be accepted or rejected.
    virtual bool acceptChange(
      pqTreeWidgetItem* /*item*/,
      const QVariant& /*curValue*/, const QVariant& /*newValue*/,
      int /*column*/, int /*role*/)
      { return true; }
    };

  /// Set the name of the callback slot to call
  void setCallbackHandler(pqCallbackHandler* hdlr)
    { this->CallbackHandler = hdlr; }

protected:
  pqCallbackHandler* CallbackHandler;
};

#endif


