Update child zIndex in andengine? - andengine

Question

In my game application, many child are added on main scene at run time andI want to give zIndex to a new child at run time but it is not taken into account. To give zIndex to the child I use code like :
mySprite.setZIndex(1);
But if I refresh the main scene at run time, then the child will take its zIndex properly. For refreshing the main scene, I use the code below :
mainScene.sortChildren();
But if I use the above code at run time, then it gives jerk to all child and you know its looks very bad ! Then, how to sort main scene children without jerk ?
Edit
I try to explain my issue with code and comments. In the code below, three methods : one method adds animated sprites into the main scene and one draw line method draw line into the main scene and my animsprite move on the line because line zIndex is 2 and myAnimSprit zIndex 3 so. But after every 5 seconds, I want to update z Index of animsprite like 1 in this example so line is on my animSprite that is done by changeZIndex method and it called by timer.
public class TouchPark extends BaseGameActivity {
private AnimatedSprite animSprite;
private Scene mainScene;
// load engine and load all resoureces here
#Override
public Scene onLoadScene(){
mainScene = new Scene();
createTimerHandler();
addAnimatedSprite()
}
public void addAnimatedSprite(){
animatedSprite = new AnimatedSprite(- mTextureRegion.getWidth(), - mTextureRegion.getHeight(), mTextureRegion.deepCopy());
animSprite.setZIndex(3);
animSprite.setPosition(initX, initY);
mainScene.attachChild(animSprite);
}
public void drawLine(ArrayList<Float> xList , ArrayList<Float> yList){
float x1 = xList.get(xListLength - 2);
float x2 = xList.get(xListLength - 1);
float y1 = yList.get(yListLength - 2);
float y2 = yList.get(yListLength - 1);
Line line = new Line(x1, y1 , x2 ,y2 , lineWidth);
line.setZIndex(2); //my sprite move on the line so that line zIndex is 2 and animSprite zIndex is 3
line.setColor(1, 0, 0);
mainScene.attachChild(line);
}
public void changeZIndex(){
animSprite.setZIndex(1); // now i want line is on the my animSprite so i changed zIndex of line
//but here it will not change zIndex of my animsprite at runTime
//but if i write below code then it will get effect
mainScene.sortChildren();
//but above code update not only one aimSprite but also all sprite that are presents on the mainScene
//and it look like all chilrens get jerk
}
public void createTimerHandler(){
mGeneralTimerHandler = new TimerHandler(5.0f, true, new ITimerCallback() {
public void onTimePassed(TimerHandler pTimerHandler) {
changeZIndex();
}
getEngine().registerUpdateHandler(mGeneralTimerHandler);
}
}

Answer 1

first load all the resources in your Scene.
After that implement below line..
GameActivity.activity.getEngine().setScene(yourScene);
user cannot view the scene till you call above line.
So that it wont show that jerks.

Answer 2

Intialize an Entity with highest Zorder .Then add all dynamically created sprites to his entity. If it is not cleared then post the code