MagnetizedGroup.jsx

function MagnetizedGroup(items){
    this.items = items;
    this.state = this.calculateState();
    this.handler = this.getObjectChangeHandler();
};

MagnetizedGroup.prototype.calculateState = function calculateState(){
    var state = [];
    for(var index = 0; index < this.items.length; index++){
        
        var item = this.items[index];
        
        if(!item || !item.isValid || !("paths" in item)) continue;

        state.push({
            item:item,
            points:Array.prototype.concat.apply([],item.paths.everyItem().entirePath),
            cornerOptions: CornerOptUtils.extract(item,{})
        });
    }
    return state;
};

MagnetizedGroup.prototype.magnetize = function magnetize(){
    app.addEventListener("afterSelectionAttributeChanged", this.handler);
};
MagnetizedGroup.prototype.demagnetize = function demagnetize(){
    app.removeEventListener("afterSelectionAttributeChanged", this.handler);
};
MagnetizedGroup.prototype.remove = function remove(index){
    this.items.length > index && this.items.splice(index, 1);
};
MagnetizedGroup.prototype.add = function add(item){
    this.items.push(item);
};
MagnetizedGroup.prototype.rearrange = function rearrange(from, to){
    this.items.splice(to, 0 , this.items.splice(from, 1)[0]);
};

MagnetizedGroup.prototype.getObjectChangeHandler = function getObjectChangeHandler(){
    var context = this;
    return function(){
        var changedObject = context.detectChangedObject(context.state);
        if(changedObject){
            for(var itemIndex = 0; itemIndex < context.items.length; itemIndex++){
                var item = context.items[itemIndex];
                item != changedObject && context.copyPath(changedObject, item);
            }
        }
        context.state = context.calculateState();
    }
}

MagnetizedGroup.prototype.detectChangedObject = function detectChangedObject(lastState){
    for(var index = 0; index < lastState.length; index++){
        var itemState = lastState[index];

        var item = itemState.item;

        if(!item || !item.isValid){
            continue;
        }

        var currentPoints = Array.prototype.concat.apply([],item.paths.everyItem().entirePath);
        if(!arrayEquivalent(currentPoints, itemState.points) || CornerOptUtils.changed(item, itemState.cornerOptions)){
            return item;
        }

    }
    return null;
};

MagnetizedGroup.prototype.copyPath = function copyPath(from, to){
    
    if(from && to && from.isValid && to.isValid){
        
        var pathPoints = from.paths.everyItem().entirePath;
        var asCollection = Array.prototype.concat.apply([], pathPoints);
        var cornerOptions = CornerOptUtils.extract(from, {});
        var pathType = to.paths.firstItem().pathType;
        
        try{
            to.convertShape(ConvertShapeOptions.CONVERT_TO_RECTANGLE);
        }catch(err){};
        
        to.paths.everyItem().pathType = pathType;
        to.paths.everyItem().entirePath = asCollection;

        CornerOptUtils.inject(to, cornerOptions);
    }
}