CenterLayout.java

/**
 * Copyright (c) 2003-2009, Xith3D Project Group all rights reserved.
 * 
 * Portions based on the Java3D interface, Copyright by Sun Microsystems.
 * Many thanks to the developers of Java3D and Sun Microsystems for their
 * innovation and design.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 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 the 'Xith3D Project Group' 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 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER 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) A
 * RISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE
 */
package org.xith3d.ui.hud.layout;

import java.util.ArrayList;

import org.xith3d.ui.hud.base.Widget;

/**
 * The {@link CenterLayout} centers the {@link Widget}s at the container's
 * center. If more than one Widget is contained, then they can either be
 * arranged horizontally or vertically. The default is vertically.
 * 
 * @author Marvin Froehlich (aka Qudus)
 */
public class CenterLayout extends LayoutManagerBase
{
    public static enum Orientation
    {
        VERTICAL,
        HORIZONTAL
    }
    
    private Orientation orientation;
    
    private float gap;
    
    public void setOrientation( Orientation orientation )
    {
        if ( orientation == null )
            throw new IllegalArgumentException( "orientation must not be null" );
        
        this.orientation = orientation;
    }
    
    public final Orientation getOrientation()
    {
        return ( orientation );
    }
    
    public void setGap( float gap )
    {
        this.gap = gap;
    }
    
    public final float getGap()
    {
        return ( gap );
    }
    
    /**
     * {@inheritDoc}
     */
    @Override
    protected void doLayout( final float left0, final float top0, final float containerResX, final float containerResY )
    {
        final ArrayList< Widget > widgets = getWidgets();
        
        if ( widgets.size() > 0 )
        {
            final float centerX = left0 + containerResX / 2f;
            final float centerY = top0 + containerResY / 2f;
            
            if ( getOrientation() == Orientation.HORIZONTAL )
            {
                float totalWidth = 0f;
                
                for ( int i = 0; i < widgets.size(); i++ )
                {
                    final Widget widget = widgets.get( i );
                    
                    if ( !widget.isVisible() && getInvisibleWidgetsHidden() )
                        continue;
                    
                    if ( i > 0 )
                        totalWidth += getGap();
                    
                    totalWidth += widget.getWidth();
                }
                
                float left = centerX - ( totalWidth / 2f );
                
                for ( int i = 0; i < widgets.size(); i++ )
                {
                    final Widget widget = widgets.get( i );
                    
                    if ( !widget.isVisible() && getInvisibleWidgetsHidden() )
                        continue;
                    
                    widget.setLocation( left, centerY - ( widget.getHeight() / 2f ) );
                    
                    left += widget.getWidth() + getGap();
                }
            }
            else if ( getOrientation() == Orientation.VERTICAL )
            {
                float totalHeight = 0f;
                
                for ( int i = 0; i < widgets.size(); i++ )
                {
                    final Widget widget = widgets.get( i );
                    
                    if ( !widget.isVisible() && getInvisibleWidgetsHidden() )
                        continue;
                
                    if ( i > 0 )
                        totalHeight += getGap();
                    
                    totalHeight += widget.getHeight();
                }
                
                float top = centerY - ( totalHeight / 2f );
                
                for ( int i = 0; i < widgets.size(); i++ )
                {
                    final Widget widget = widgets.get( i );
                    
                    if ( !widget.isVisible() && getInvisibleWidgetsHidden() )
                        continue;
                    
                    widget.setLocation( centerX - ( widget.getWidth() / 2f ), top );
                    
                    top += widget.getHeight() + getGap();
                }
            }
        }
    }
    
    public CenterLayout( Orientation orientation, float gap )
    {
        if ( orientation == null )
            throw new IllegalArgumentException( "orientation must not be null" );
        
        if ( gap < 0f )
            throw new IllegalArgumentException( "gap must be >= 0" );
        
        this.orientation = orientation;
        this.gap = gap;
    }
    
    public CenterLayout( Orientation orientation )
    {
        this( orientation, 0f );
    }
    
    public CenterLayout( float gap )
    {
        this( Orientation.VERTICAL, gap );
    }
    
    public CenterLayout()
    {
        this( Orientation.VERTICAL, 0f );
    }
}