/*
  Copyright (C) 2000-2012 Novell, Inc
  This library is free software; you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as
  published by the Free Software Foundation; either version 2.1 of the
  License, or (at your option) version 3.0 of the License. This library
  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 Lesser General Public
  License for more details. You should have received a copy of the GNU
  Lesser General Public License along with this library; if not, write
  to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
  Floor, Boston, MA 02110-1301 USA
*/


/*-/

  File:		YPartitionSplitter.h

  Author:	Stefan Hundhammer <shundhammer@suse.de>

/-*/

#ifndef YPartitionSplitter_h
#define YPartitionSplitter_h

#include "YWidget.h"


struct YPartitionSplitterPrivate;


/**
 * PartitionSplitter: A (very custom) widget for easily splitting one existing
 * partition into two.
 *
 * Layout:
 *
 *     +--------------------+---------------+--------------------------+
 *     | Old Partition      | Old Partition | New Partition            |
 *     | used               | free          |                          |
 *     +--------------------+---------------+--------------------------+
 *
 *     Old Partition free                                  New Partition
 *     [ 123 ] ================O================================ [ 123 ]
 *
 *
 * At the top, there is a BarGraph that dynamicylla displays the sizes in
 * graphical form. Below are an IntField to the left and an IntField to the
 * right, each with its respective label. Between the two IntFields there is a
 * Slider.
 *
 * The user can enter a value in either IntField or drag the slider. The other
 * sub-widgets (including the BarGraph) will automatically be
 * adjusted. Visually (in the BarGraph), the border between "old partition
 * free" and "new partition" will move left and right. The border between "old
 * partition used" and "old partition free" is static.
 *
 * There are built-in (configurable) limits for the minimum sizes of "old
 * partition free" and "new partition".
 **/
class YPartitionSplitter : public YWidget
{
protected:
    /**
     * Constructor.
     *
     * usedSize:	Used size of the old partition (constant)
     *
     * totalFreeSize:	Total free size of the old partition before the split:
     *			OldPartitionFree + NewPartition
     *
     * newPartSize':	Initial size of the new partition
     *
     * minNewPartSize:	Miminum size of the new partition
     *
     * minFreeSize:	Minimum free size of the old partition
     *
     * usedLabel:	BarGraph label for the used part of the old partition
     *
     * freeLabel:	BarGraph label for the free part of the old partition
     *
     * newPartLabel:	BarGraph label for the new partition
     *
     * freeFieldLabel:	IntField label for the free part of the old partition
     *
     * newPartFieldLabel: IntField label for the size of the new partition
     **/
    YPartitionSplitter( YWidget *		parent,
			int			usedSize,
			int			totalFreeSize,
			int			newPartSize,
			int			minNewPartSize,
			int			minFreeSize,
			const std::string &	usedLabel,
			const std::string &	freeLabel,
			const std::string &	newPartLabel,
			const std::string &	freeFieldLabel,
			const std::string &	newPartFieldLabel );

public:

    /**
     * Destructor.
     **/
    virtual ~YPartitionSplitter();

    /**
     * Returns a descriptive name of this widget class for logging,
     * debugging etc.
     **/
    virtual const char * widgetClass() const { return "YPartitionSplitter"; }

    /**
     * The value of this PartitionSplitter: The size of the new partition.
     *
     * Derived classes are required to implement this.
     **/
    virtual int value() = 0;

    /**
     * Set the value (the size of the new partition).
     *
     * Derived classes are required to implement this.
     **/
    virtual void setValue( int newValue ) = 0;


    // Access methods

    int 	usedSize()         	const;
    int 	totalFreeSize()    	const;
    int 	minFreeSize()        	const;
    int 	maxFreeSize()        	const	{ return totalFreeSize() - minNewPartSize(); }
    int		freeSize()			{ return totalFreeSize() - newPartSize(); }
    int 	newPartSize()			{ return value(); }
    int 	minNewPartSize()	const;
    int		maxNewPartSize()	const	{ return totalFreeSize() - minFreeSize(); }

    std::string	usedLabel()          	const;
    std::string freeLabel()          	const;
    std::string newPartLabel()         	const;
    std::string freeFieldLabel()     	const;
    std::string newPartFieldLabel()    	const;

    /**
     * Set a property.
     * Reimplemented from YWidget.
     *
     * This function may throw YUIPropertyExceptions.
     *
     * This function returns 'true' if the value was successfully set and
     * 'false' if that value requires special handling (not in error cases:
     * those are covered by exceptions).
     **/
    virtual bool setProperty( const std::string    & propertyName,
			      const YPropertyValue & val );

    /**
     * Get a property.
     * Reimplemented from YWidget.
     *
     * This method may throw YUIPropertyExceptions.
     **/
    virtual YPropertyValue getProperty( const std::string & propertyName );

    /**
     * Return this class's property set.
     * This also initializes the property upon the first call.
     *
     * Reimplemented from YWidget.
     **/
    virtual const YPropertySet & propertySet();


    /**
     * The name of the widget property that will return user input.
     * Inherited from YWidget.
     **/
    const char * userInputProperty() { return YUIProperty_Value; }


private:

    ImplPtr<YPartitionSplitterPrivate> priv;
};


#endif // YPartitionSplitter_h
