Phaser group to layout children in rows or columns (work in progress)

hvlayoutgroup.ts

// Author Brad P. Taylor (bradptaylor+github@gmail.com) license MIT
///<reference path="../../../../bower_components/phaser-official/build/phaser.d.ts"/>
///<reference path="./extendedgroup.ts"/>

module bpt {

    export interface ILayoutController {
        onlayoutChange:Phaser.Signal;
        requestLayout();
        handleLayout();
    }

    export class HVLayoutGroup extends bpt.prefab.ExtendedGroup implements ILayoutController {

        private pendingLayoutRequest:boolean = false;
        private hgap_:number;
        private vgap_:number;

        contentWidth:number = undefined;
        contentHeight:number = undefined;
        onlayoutChange:Phaser.Signal;

        constructor( game, private fixed_size_ = 0, private horizontal_ = true, private fixed_count_ = 1, gap = 5 ) {
            super(game);
            this.hgap_ = gap;
            this.vgap_ = gap;
            this.onlayoutChange = this.createSignal();
        }

        get horizontal():boolean {
            return this.horizontal_;
        }

        set horizontal(bHorizontal:boolean) {
            if ( bHorizontal === this.horizontal_ ) return;
            this.horizontal_ = bHorizontal;
            this.requestLayout();
        }

        get hgap():number {
            return this.hgap_;
        }

        set hgap( n:number ) {
            if ( 0 > n ) n = 0;
            if ( n === this.hgap_ ) return;
            this.hgap_ = n;
            this.requestLayout();
        }

        get vgap():number {
            return this.vgap_;
        }

        set vgap( n:number ) {
            if ( 0 > n ) n = 0;
            if ( n === this.vgap_ ) return;
            this.vgap_ = n;
            this.requestLayout();
        }

        get fixed_count():number {
            return this.fixed_count_;
        }

        set fixed_count( n:number ) {
            if ( 0 > n ) n = 0;
            if ( n === this.fixed_count_ ) return;
            this.fixed_count_ = n;
            this.requestLayout();
        }

        get fixed_size():number {
            return this.fixed_size_ || this.findLargestVisibleUnscaledDimension();
        }

        set fixed_size( n:number ) {
            if ( 0 > n ) n = 0;
            if ( n === this.fixed_size_ ) return;
            this.fixed_size_ = n;
            this.requestLayout()
        }

        findLargestVisibleUnscaledDimension() {

            var w = 0, h = 0;

            for ( var i = 0, l = this.children.length; i < l; ++i ) {

                var child = this.children[i];
                if (!child.visible) continue;
                var bounds = child.getLocalBounds();
                if ( w < bounds.width ) w = bounds.width;
                if ( h < bounds.height ) h = bounds.height;

            }

            return this.horizontal_ ? w : h;
        }

        trace:boolean = false;

        handleLayout() {

            this.pendingLayoutRequest = false;

            var fixedSize = this.fixed_size;

            var bHorizontal = this.horizontal_,
                fw = bHorizontal ? fixedSize : 0,
                fh = bHorizontal ? 0 : fixedSize,
                hg = this.hgap_,
                vg = this.vgap_,
                iw = fw - (hg*2),
                ih = fh - (vg*2),
                count = this.fixed_count_;

            var mw = 0, mh = 0, row = 0, col = 0, content_width = 0, content_height = 0;
            var x = hg, y = vg;

            for ( var i = 0, l = this.children.length; i < l; ++i ) {

                var child = this.children[i];
                if ( !child.visible ) continue;

                var bounds = child.getBounds();
                if ( !bounds.width || !bounds.height ) continue;

                var scale = (bHorizontal) ? (iw / bounds.width) : (ih / bounds.height);
                var aw = bounds.width * scale;
                var ah = bounds.height * scale;

                var anchor:any = child['anchor'];
                var cax = (anchor && anchor.x) || 0;
                var cay = (anchor && anchor.y) || 0;

                child.scale.set( scale, scale );
                child.position.x = x + aw * cax;
                child.position.y = y + ah * cay;

                if ( this.trace ) console.log( "layout", child.position.x, child.position.y, "size", aw, ah, "scale", scale, "bounds", bounds.width, bounds.height );

                if ( bHorizontal ) {

                    if ( ah > mh ) mh = ah;
                    x += fw - hg;

                    if ( ++col === count ) {

                        y += mh + vg;
                        content_width = x;
                        content_height = y;
                        x = hg;
                        col = 0;
                        mh = 0;

                    }

                } else {

                    if ( aw > mw ) mw = aw;
                    y += fh - vg;

                    if ( ++row === count ) {

                        x += mw + hg;
                        content_width = x;
                        content_height = y;
                        y = vg;
                        row = 0;
                        mw = 0;

                    }

                }

            }

            if ( this.contentWidth !== content_width || this.contentHeight !== content_height ) {

                this.contentWidth = content_width;
                this.contentHeight = content_height;
                this.onlayoutChange.dispatch( this, this.contentWidth, this.contentHeight );

            }

        }

        requestLayout() {
            if ( this.pendingLayoutRequest ) return;
            this.pendingLayoutRequest = true;
            this.addOnceUpdate( true, this, this.handleLayout );
        }

        updateZ() {
            this.requestLayout();
            super.updateZ();
        }

        releaseReferences() {
            this.onlayoutChange = undefined;
            super.releaseReferences();
        }
    }

    bpt.prefab.Factory.add('bpt.HVLayoutGroup', HVLayoutGroup,
        [ ["fixed"], ["horizontal"], ["count"], ["gap"] ],
        bpt.prefab.helper_transformed_named_args_to_config);

    bpt.prefab.Factory.addAlias('HVLayoutGroup', 'bpt.HVLayoutGroup');

}