/*
 
* Copyright (c) 2016, Metron, Inc.
 
* All rights reserved.
 
*
 
* Redistribution and use in source and binary forms, with or without
 
* modification, are permitted provided that the following conditions are met:
 
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* Redistributions of source code must retain the above copyright
 
*
       
notice, this list of conditions and the following disclaimer.
 
*
     
* Redistributions in binary form must reproduce the above copyright
 
*
       
notice, this list of conditions and the following disclaimer in the
 
*
       
documentation and/or other materials provided with the distribution.
 
*
     
* Neither the name of Metron, Inc. nor the
 
*
       
names of its contributors may be used to endorse or promote products
 
*
       
derived from this software without specific prior written permission.
 
*
 
* 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
 
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package com.metsci.glimpse.axis.tagged;

import java.util.ArrayList;
import java.util.List;
import java.util.function.Consumer;

import com.metsci.glimpse.axis.Axis1D;
import com.metsci.glimpse.axis.listener.AxisListener1D;

/**
 
* An AxisListener1D which only reports when axis tags have changed.
 
* Changes to name, value, or number of tags are reported, but changes
 
* to Tag attributes or their values do not trigger the listener.
 
*
 
* @author ulman
 
*/

public abstract class TaggedAxisListener1D implements AxisListener1D
{

    
public static TaggedAxisListener1D newTaggedAxisListener1D( Consumer<TaggedAxis1D> tagsUpdatedFn )
    
{
        
return new TaggedAxisListener1D( )
        
{
            
@Override
            
public void tagsUpdated( TaggedAxis1D axis )
            
{
                
tagsUpdatedFn.accept( axis );
            
}
        
};
    
}


    
protected List<Tag> previous;

    
@Override
    
public void axisUpdated( Axis1D axis )
    
{
        
if ( axis == null ) return;

        
if ( axis instanceof TaggedAxis1D )
        
{
            
TaggedAxis1D taggedAxis = ( TaggedAxis1D ) axis;

            
List<Tag> current = taggedAxis.getSortedTags( );
            
if ( haveTagsChanged( previous, current ) )
            
{
                
tagsUpdated( taggedAxis );

                
previous = copyTags( current );
            
}
        
}
    
}

    
protected List<Tag> copyTags( List<Tag> list )
    
{
        
List<Tag> newList = new ArrayList<Tag>( list.size( ) );
        
for ( Tag tag : list )
        
{
            
newList.add( new Tag( tag ) );
        
}
        
return newList;
    
}

    
protected boolean haveTagsChanged( List<Tag> previous, List<Tag> current )
    
{
        
if ( previous == null && current != null ) return true;
        
if ( previous != null && current == null ) return true;
        
if ( previous == null && current == null ) return false;
        
if ( previous.size( ) != current.size( ) ) return true;

        
for ( int i = 0; i < previous.size( ); i++ )
        
{
            
Tag previousTag = previous.get( i );
            
Tag currentTag = current.get( i );

            
// compare names first
            
if ( !previousTag.equals( currentTag ) ) return true;
            
if ( previousTag.getValue( ) != currentTag.getValue( ) ) return true;
        
}

        
return false;
    
}

    
public abstract void tagsUpdated( TaggedAxis1D axis );
}