Android: activity transition/animation in ActivityGroup

 use ActivityGroup to manage activities, I want to add animation when change activity, the code I used to change to next activity is:

Intent intent = new Intent(getParent(), AnotherActivity.class);
TabGroupActivity parentActivity = (TabGroupActivity) getParent();
parentActivity.startChildActivity("AnotherActivity", intent);

And inside startChildActivity:

Window window =getLocalActivityManager().startActivity(Id,intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP));
if (window != null) {
    View view = window.getDecorView();
    mIdList.add(Id);
    setContentView(view);
}

TabGroupActivity is just an ActivityGroup, provides some useful methods. With the above code, what/where do I add to enable animation?

I needed to implement wizard with page transitions sometime ago. And I used ActivityGroup approach. It had Wizard (inherited from AcitivtyGroup) and WizardPage (inherited from Activity).WizardPage had code that handled animations, while Wizard was responsible to call those animations in appropriate times.

WizardPage class:

/**
 * Called to animate appearance of this activity 
 * as if somebody clicked next on previous activity 
 * and ended up to this activity.
 * 
 * Animation:  <---- 
 */
void onAnimateOpenAsNext()
{           
    animateTransition(android.R.attr.activityOpenEnterAnimation);
}

/**
 * Called to animate appearance of this activity 
 * as if somebody clicked back on previous activity 
 * and ended up to this activity.
 * 
 * Animation:  ----> 
 */
void onAnimateOpenAsPrev()
{
    animateTransition(android.R.attr.activityCloseEnterAnimation);
}   

/**
 * Called to animate disappearance of this acitivity 
 * when "next" button was clicked
 * 
 * Animation:  <-- 
 */
void onAnimateCloseOnNext()
{   
    animateTransition(android.R.attr.activityOpenExitAnimation);
}


/**
 * Called to animate disappearance of this activity 
 * when "prev" button was clicked
 * 
 * Animation:  --> 
 */ 
void onAnimateCloseOnPrev()
{       
    animateTransition(android.R.attr.activityCloseExitAnimation);
}

private void animateTransition(int animAttributeId)
{       
    TypedValue animations = new TypedValue();       
    Theme theme = this.getTheme();

    theme.resolveAttribute(android.R.attr.windowAnimationStyle, animations, true);      
    TypedArray animationArray = obtainStyledAttributes(animations.resourceId, 
                                                        new int[] {animAttributeId});

    int animResId = animationArray.getResourceId(0, 0);
    animationArray.recycle();

    if(animResId != 0)
    {
        try
        {
            Animation anim = AnimationUtils.loadAnimation(this, animResId);             
            getWindow().getDecorView().startAnimation(anim);
        }
        catch(Resources.NotFoundException ex)
        {
            //didn't find animation resource, ignore error
        }
    }               
}

Wizard had startPage method which was called to make the actual activity transitions:

public void startPage(int i)
{
    int prevIndex = getCurrentPageIndex();
    m_pageIndex = i;        

    WizardPage currentPage = getCurrentPage();  
    if(currentPage != null)
    {
        if(prevIndex <= i)
        {
            currentPage.onAnimateCloseOnNext();
        }
        else
        {
            currentPage.onAnimateCloseOnPrev();
        }
    }

    LocalActivityManager manager =  getLocalActivityManager();        

    m_startingActivity = true;
    Window activityWindow = manager.startActivity(Integer.toString(i), m_pageIntens.get(i));
    m_startingActivity = false;

    setContentView(activityWindow.getDecorView());


    currentPage = getCurrentPage();  

    if(currentPage != null)
    {
        if(prevIndex <= i)
        {
            getCurrentPage().onAnimateOpenAsNext();
        }
        else
        {
            getCurrentPage().onAnimateOpenAsPrev();
        }
    }