DistributionCollection

/*
    CASA Framework for ActionScript 2.0
    Copyright (C) 2007  CASA Framework
    http://casaframework.org
    
    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) any later version.
    
    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
*/

import org.casaframework.core.CoreObject;
import org.casaframework.math.geom.Rectangle;
import org.casaframework.util.ArrayUtil;
import org.casaframework.util.TypeUtil;

/**
    Creates the mechanism to distribute <code>MovieClip</code>s, <code>TextField</code>s and <code>Button</code>s to a vertical or horzontal grid of columns and rows.
    
    @author Aaron Clinger
    @version 02/06/07
    @example
        <code>
            var distribution:DistributionCollection = new DistributionCollection();
            this.distribution.setRectangle(new Rectangle(10, 10, 400, Number.POSITIVE_INFINITY));
            this.distribution.setMargin(0, 5, 5, 0);
            
            var len:Number = 5;
            while (len--)
                this.distribution.addItem(this.attachMovie("box", "box" + len + "_mc", this.getNextHighestDepth()));
        </code>
*/

class org.casaframework.layout.DistributionCollection extends CoreObject {
    private var $margin:Object;
    private var $rect:Rectangle;
    private var $bounding:Rectangle;
    private var $collection:Array;
    private var $isVert:Boolean;
    
    
    public function DistributionCollection() {
        super();
        
        this.$collection = new Array();
        this.$margin     = new Object();
        this.$margin.top = this.$margin.right = this.$margin.bottom = this.$margin.left = 0;
        
        this.$setClassDescription('org.casaframework.layout.DistributionCollection');
    }
    
    /**
        Defines the area and position of the distribution.
        
        @param rectangle: A rectangle defining either the max width or height boundries of the distribution
        @return Returns <code>true</code> if the rectangle was valid and applied; otherwise <code>false</code>.
        @usageNote Either the rectangle's width or height must defined as <code>Number.POSITIVE_INFINITY</code>.
    */
    public function setRectangle(rectangle:Rectangle):Boolean {
        if (rectangle.getWidth() == Number.POSITIVE_INFINITY || rectangle.getHeight() == Number.POSITIVE_INFINITY) {
            if (rectangle.getWidth() != Number.POSITIVE_INFINITY) {
                this.$rect   = rectangle.clone();
                this.$isVert = true;
                
                this.update();
                
                return true;
            } else if (rectangle.getHeight() != Number.POSITIVE_INFINITY) {
                this.$rect   = rectangle.clone();
                this.$isVert = false;
                
                this.update();
                
                return true;
            }
        }
        
        return false;
    }
    
    /**
        @return Returns the area and position of the distribution that was defined with {@link #setRectangle}.
    */
    public function getDistributionRectangle():Rectangle {
        return this.$rect.clone();
    }
    
    /**
        @return Returns the actual area and position the items in the distribution occupy.
    */
    public function getBoundingRectangle():Rectangle {
        return this.$bounding.clone();
    }
    
    /**
        Defines the spacing between items in the distribution.
        
        @param marginTop: Sets the top spacing of an element.
        @param marginRight: Sets the right spacing of an element.
        @param marginBottom: Sets the bottom spacing of an element.
        @param marginLeft: Sets the left spacing of an element.
    */
    public function setMargin(marginTop:Number, marginRight:Number, marginBottom:Number, marginLeft:Number):Void {
        this.$margin.top    = (marginTop == undefined) ? 0 : marginTop;
        this.$margin.right  = (marginRight == undefined) ? 0 : marginRight;
        this.$margin.left   = (marginLeft == undefined) ? 0 : marginLeft;
        this.$margin.bottom = (marginBottom == undefined) ? 0 : marginBottom;
        
        this.update();
    }
    
    /**
        Adds item to receive distribution position updates.
        
        @param item: A <code>MovieClip</code>, <code>TextField</code> or <code>Button</code>.
        @return Returns <code>true</code> if item was of type <code>MovieClip</code>, <code>TextField</code> or <code>Button</code> and was successfully added; otherwise <code>false</code>.
    */
    public function addItem(item:Object):Boolean {
        switch (TypeUtil.getTypeOf(item)) {
            case 'button' :
            case 'movieclip' :
            case 'textfield' :
                if (ArrayUtil.contains(this.$collection, item) != 0) return false;
                
                this.$collection.push(item);
                this.update();
                return true;
            default :
                return false;
        }
    }
    
    /**
        Removes item previously added with {@link #addItem} from receiving distribution updates. Leaves item at its current position.
        
        @param item: A <code>MovieClip</code>, <code>TextField</code> or <code>Button</code> you wish to remove.
        @return Returns <code>true</code> if item was successfully found and removed; otherwise <code>false</code>.
    */
    public function removeItem(item:Object):Boolean {
        if (ArrayUtil.removeArrayItem(this.$collection, item) > 0) {
            this.update();
            return true;
        }
        
        return false;
    }
    
    /**
        Applies the distribution layout for all items added with {@link #addItem}.
        
        @usageNote <code>update</code> is automatically called after {@link #addItem}, {@link #removeItem}, {@link #setRectangle} and {@link #setMargin}.
    */
    public function update():Void {
        if (this.$rect == undefined)
            return;
        
        var i:Number             = -1;
        var row:Number           = 0;
        var column:Number        = 0;
        var largest:Number       = 0;
        var largestWidth:Number  = 0;
        var largestHeight:Number = 0;
        
        var h:Number;
        var w:Number;
        var item:Object;
        
        while (++i < this.$collection.length) {
            item = this.$collection[i];
            
            w = item._width  + this.$margin.left + this.$margin.right;
            h = item._height + this.$margin.top + this.$margin.bottom;
            
            if (this.$isVert) {
                column += w;
                
                if (column > this.$rect.getWidth()) {
                    row += (largest == 0) ? row : largest;
                    
                    largest = 0;
                    column  = w;
                }
                
                if (h > largest)
                    largest = h;
                
                if (column > largestWidth)
                    largestWidth = column;
                
                item._x = column - item._width - this.$margin.right + this.$rect.getX();
                item._y = row + this.$margin.top + this.$rect.getY();
            } else {
                row += h;
                
                if (row > this.$rect.getHeight()) {
                    column += (largest == 0) ? column : largest;
                    
                    largest = 0;
                    row     = h;
                }
                
                if (w > largest)
                    largest = w;
                
                if (row > largestHeight)
                    largestHeight = row;
                
                item._x = column + this.$margin.left + this.$rect.getX();
                item._y = row - item._height - this.$margin.bottom + this.$rect.getY();
            }
        }
        
        if (this.$bounding != undefined)
            this.$bounding.destroy();
        
        this.$bounding = this.$rect.clone();
        this.$bounding.setWidth(this.$isVert ? largestWidth : column + w);
        this.$bounding.setHeight(this.$isVert ? row + h : largestHeight);
    }
    
    public function destroy():Void {
        this.$rect.destroy();
        this.$bounding.destroy();
        
        delete this.$margin;
        delete this.$rect;
        delete this.$bounding;
        delete this.$collection;
        delete this.$isVert;
        
        super.destroy();
    }
}