Hi all, this is a question for the more experienced script programmers. I was looking at ways to optimize my code and I found that it would be handy if I could assign custom fields to item objects, because then I would be able to store calculated values on the item and if be able to use them in functions to which I would only have to pass the item as argument and not also the calculated value. Actually I wouldn’t even have to pass the items as an argument to the functions because I could make the function run on the item.

After some searching I found this: http://stackoverflow.com/questions/1646698/what-is-the-new-keyword-in-javascript

I implemented this in a small example script:

dummy = LL.getCurrentDesktop().addShortcut(“dummy”,new Intent(),0,0);

// OLD WAY

/*

function displayCenter(it, center){

it.setLabel(center[0]+”,”+center[1]);

}

function moveToCenter(it, center){

it.setPosition(center[0], center[1]);

}

function center(item){

var r=item.getRotation()*Math.PI/180;

var sin=Math.abs(Math.sin(r));

var cos=Math.abs(Math.cos(r));

var w=item.getWidth()*item.getScaleX();

var h=item.getHeight()*item.getScaleY();

return[item.getPositionX()+(w*cos+h*sin)*0.5,item.getPositionY()+(h*cos+w*sin)*0.5];

}

var center = center(dummy);

displayCenter(dummy, center);

moveToCenter(dummy, center);

*/

//NEW WAY:

myItem = function(){

this.getCenter = function(){

if(this.center==null){

alert(“test”)

var r=this.getRotation()*Math.PI/180;

var sin=Math.abs(Math.sin(r));

var cos=Math.abs(Math.cos(r));

var w=this.getWidth()*this.getScaleX();

var h=this.getHeight()*this.getScaleY();

var center = [this.getPositionX()+(w*cos+h*sin)*0.5,this.getPositionY()+(h*cos+w*sin)*0.5]

this.center = center;

}

return this.center;

};

this.displayCenter = function(){

this.setLabel(this.getCenter()[0]+”, “+this.getCenter()[1]);

};

this.moveToCenter = function(){

this.setPosition(this.getCenter()[0], this.getCenter()[1]);

};

};

myItem.prototype = dummy;

myDummy = new myItem();

myDummy.displayCenter();

myDummy.moveToCenter();

myDummy.setSize(288, myDummy.getHeight()) //ALSO STILL WORKS BOTH WORK ON SAME OBJECT DESPITE THAT I DIDN’T DEFINE A getPositionX() IN myItem 😀

As you can see this enables me to do what I explained herebove, but I haven’t seen anyone do it before, so I am wondering if there is anything bad happening here or I actually found something cool and useful.

Please tell me what you think in the comments.

Thanks for reading 🙂

cdfa

http://stackoverflow.com/questions/1646698/what-is-the-new-keyword-in-javascript

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Hi all, this is a question for the more experienced users: I was looking at ways to optimize my code and I found that I would be handy if I could assign custom fields to item objects, but LL doesn’t allow me to. The I found this: http://stackoverflow.com/questions/1646698/what-is-the-new-keyword-in-javascript

I implemented this in a small example script:

dummy = LL.getCurrentDesktop().addShortcut(“dummy”,new Intent(),0,0);

myItem = function(){

this.getCenter = function(){

var r=this.getRotation()*Math.PI/180;

var sin=Math.abs(Math.sin(r));

var cos=Math.abs(Math.cos(r));

var w=this.getWidth()*this.getScaleX();

var h=this.getHeight()*this.getScaleY();

return[this.getPositionX()+(w*cos+h*sin)*0.5,this.getPositionY()+(h*cos+w*sin)*0.5];

};

};

myItem.prototype = dummy;

myDummy = new myItem();

alert(myDummy.getCenter()[0])

alert(myDummy.getPositionX()) // BOTH WORK ON SAME OBJECT AND DIDN’T DEFINE A getPositionX() IN myItem 😀

I never seen anyone use this, so I was wondering if there is anything that makes this very inefficient or I actually discovered something pretty cool.

Thanks for reading 🙂

Colin

http://stackoverflow.com/questions/1646698/what-is-the-new-keyword-in-javascript

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