fadein child when calling addChild

Question

Everywhere I've looked has instructed me to download plugins and addons because they're "superior." I'm just looking for a simple fade in/fade out when a child is added/deleted (if fadein is all I can get, I'll take it.) Here is a function I'm calling...

var trashbagFrame:MovieClip = new menu_trashbag_mc_frame();
trashbagFrame.x = 900;
trashbagFrame.y = 0;

menu_trashbag_mc.addEventListener(MouseEvent.MOUSE_UP, trashbagContent);

function trashbagContent(event:MouseEvent):void {
    if(MovieClip(root).currentFrame == 850) {
    while(MovieClip(root).numChildren > 2)
    {
        MovieClip(root).removeChild(MovieClip(root).getChildAt(MovieClip(root).numChildren - 1));
    }
MovieClip(root).addChild(trashbagFrame);
MovieClip(root).addChild (closeBtn);
}
else {
MovieClip(root).addChild(trashbagFrame);
MovieClip(root).addChild (closeBtn);
MovieClip(root).gotoAndPlay(806);
}
}

Answer 1

Most likely those sites meant the addons like Tweener and such are more flexible/simple to use when you constantly need transitions.

The ActionScript 3.0 Library has a class called Fade in the fl.transitions package.

import fl.transitions.*;
import fl.transitions.easing.*;

TransitionManager.start(img1_mc, {type:Fade, direction:Transition.IN, duration:9, easing:Strong.easeOut});

https://www.adobe.com/livedocs/flash/9.0/ActionScriptLangRefV3/fl/transitions/Fade.html

where

img1_mc

will be the object (in your case the child), that you want to apply the transition.

Answer 2

You could just use an enterFrame to change the property over time. Something like:

var trashbag:MovieClip = new MovieClip();
trashbag.alpha = 0;
addChild(trashbag);
trashbag.addEventListener(Event.ENTER_FRAME, enterFrameHandler);

var closeBtn:MovieClip = new MovieClip();
closeBtn.alpha = 0;
addChild(closeBtn);
closeBtn.addEventListener(Event.ENTER_FRAME, enterFrameHandler);

function enterFrameHandler(e:Event):void 
{
    var targetMC:MovieClip = e.currentTarget as MovieClip;
    if(targetMC.alpha >= 0.9)
    {
        targetMC.alpha = 1;
        targetMC.removeEventListener(Event.ENTER_FRAME, enterFrameHandler);
    }
    else
    {
        targetMC.alpha += 5;
    }
}

Hope that sample code helps. I haven't tested it, but the idea works.