/* This file is part of the KDE project
   Copyright (C) 2005 Cedric Pasteur <cedric.pasteur@free.fr>
   Copyright (C) 2004-2006 Jaroslaw Staniek <js@iidea.pl>

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public License
   along with this program; see the file COPYING.  If not, write to
   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
*/

#ifndef KexiDBCheckBox_H
#define KexiDBCheckBox_H

#include "kexiformdataiteminterface.h"
#include <tqcheckbox.h>

//! @short A db-aware check box
class KEXIFORMUTILS_EXPORT KexiDBCheckBox : public TQCheckBox, public KexiFormDataItemInterface
{
	TQ_OBJECT
  
	TQ_PROPERTY(TQString dataSource READ dataSource WRITE setDataSource DESIGNABLE true)
	TQ_PROPERTY(TQCString dataSourceMimeType READ dataSourceMimeType WRITE setDataSourceMimeType DESIGNABLE true)
	TQ_OVERRIDE( Tristate tristate READ isTristate WRITE setTristate )
	TQ_ENUMS( Tristate )

	public:
		KexiDBCheckBox(const TQString &text, TQWidget *parent, const char *name=0);
		virtual ~KexiDBCheckBox();

		inline TQString dataSource() const { return KexiFormDataItemInterface::dataSource(); }
		inline TQCString dataSourceMimeType() const { return KexiFormDataItemInterface::dataSourceMimeType(); }
		virtual TQVariant value();
		virtual void setInvalidState( const TQString& displayText );

		//! \return true if editor's value is null (not empty)
		//! Used for checking if a given constraint within table of form is met.
		virtual bool valueIsNull();

		//! \return true if editor's value is empty (not necessary null).
		//! Only few data types can accept "EMPTY" property
		//! (use KexiDB::Field::hasEmptyProperty() to check this).
		//! Used for checking if a given constraint within table or form is met.
		virtual bool valueIsEmpty();

		/*! \return 'readOnly' flag for this widget.  */
		virtual bool isReadOnly() const;

		/*! \return the view widget of this item, e.g. line edit widget. */
		virtual TQWidget* widget();

		virtual bool cursorAtStart();
		virtual bool cursorAtEnd();
		virtual void clear();

		virtual void setEnabled(bool enabled);

		enum Tristate { TristateDefault, TristateOn, TristateOff };

		void setTristate(Tristate tristate);
		Tristate isTristate() const;

		/*! Reimplemented after KexiFormDataItemInterface. */
		virtual void setDisplayDefaultValue(TQWidget* widget, bool displayDefaultValue);

	public slots:
		void setDataSource(const TQString &ds);
		inline void setDataSourceMimeType(const TQCString &ds) { KexiFormDataItemInterface::setDataSourceMimeType(ds); }
		void slotStateChanged(int state);

		//! This implementation just disables read only widget
		virtual void setReadOnly( bool readOnly );

	protected:
		virtual void setValueInternal(const TQVariant& add, bool removeOld);

		//! \return true in isTristate() == TristateDefault and the widget has bound data source
		//! or if isTristate() == TristateOn, else false is returned.
		bool isTristateInternal() const;

		//! Updates tristate in TQCheckBox itself according to m_tristate.
		void updateTristate();

	private:
		bool m_invalidState : 1;
		bool m_tristateChanged : 1; //!< used in setTristate()
		Tristate m_tristate; //!< used in isTristate() and setTristate()
};

#endif