Develop Reference

Animating a TextView appearing on activity creation

I want to show an animation of a TextView appearing when an activity is created. What I want is to show the activity without the TextView and then the TextView appearing (ideally, flying from outside) in its final position without user interaction.
I've tried to use the transition framework from API level 19 by having the TextView with visibility gone in the XML layout and setting it to visible in onCreate() with this code:
ViewGroup layout = (ViewGroup) findViewById(R.id.main_layout);
TransitionManager.beginDelayedTransition(layout, new ChangeBounds());
textView.setVisibility(View.VISIBLE);
This doesn't work. However, if I don't do this in onCreate() but as a response to a button click, it works. I think that the problem is that the layout is not created yet, so when I set the visibility to visible in the onCreate(), the layout is created with the final state and there aren't two scenes for the TransitionManager to work.
I've tried putting the code in onPause() but the result was the same. Any ideas how this should be done?

Try onWindowFocusChanged() like this
#Override
public void onWindowFocusChanged(boolean hasFocus) {
if(hasFocus){
// start your animation here
}
}

You should do this in onResume() after the layout has been created. Initially the visibility would be Invisible and then the view will animate.

try like this:
ViewGroup layout = (ViewGroup) findViewById(R.id.main_layout);
layout.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
TransitionManager.beginDelayedTransition(layout, new ChangeBounds());
textView.setVisibility(View.VISIBLE);
}
});
because your view should be able to animate only after it's creation

Reference R.id. in custom class

I basically made a class, with this method:
void setResource(Context context, R.id resourceID) {
ImageView test = (ImageView) context.findViewById(resourceID);
}
The "findViewById" gives me a can't resolve method.
I have three ImageViews defined in XML, I would like to set the image associated to them programatically. in my main_activty I do so by using:
ImageView blah = (ImageView) this.findViewById(R.id.blah);
Then:
blah.setImageResource(R.drawable.pony);
HOWEVER, I would like to pass everything to my class I made and have it handle all that in the custom class, but when I try to pass everything (the code at the very top; "setResource") I get that findViewByID can't resolve method. Is there a way to do it that way?

I think you are trying to find the words to express what you are trying to do, and with some of the basic concepts. This is my best guess of what you are trying to accomplish...
The code below takes an id for drawable, loads it, and then puts it into an imageView in your layout. The ImageView must already be there in your layout, it does not create one for you dynamically.
void setResource(Context context, int resourceId) {
//resourceId = R.drawable.ponies (example)
Drawable drawable = context.getResources().getDrawable(resourceId);
//R.id.main_imageview is example imageView in a layout.
ImageView iv = findViewById(R.id.main_imageview);
iv.setImageDrawable(drawable);
}

How to destroy a Layout?

I'm developing an Android app in which I use LayoutInflator to generate new layout. What the app does basically is - Its has one imageview. When I click on a button, I change the layout to display multiple ImageViews (like 2x2 or 4x4). I am successful in displaying these layouts using the LayoutInflator. However, the previous Layout stays intact and the new Layout is displayed over the old Layout which, kind of, messes the whole layout. My question is - is there anyway to destroy the old layout before displaying the new one?
Edit:
Here is the code (on the onClick event that I'm using)
public void oneby1onClick(View view){
RelativeLayout main = (RelativeLayout)findViewById(R.id.main_layout);
view = getLayoutInflater().inflate(R.layout.activity_main, main,false);
main.removeView(main);
main.addView(view);
}
public void twoby2onClick(View view){
RelativeLayout main = (RelativeLayout)findViewById(R.id.main_layout);
view = getLayoutInflater().inflate(R.layout.twoby2, main,false);
main.removeView(main);
main.addView(view);
}
public void fourby4onClick(View view){
RelativeLayout main = (RelativeLayout)findViewById(R.id.main_layout);
view = getLayoutInflater().inflate(R.layout.fourby4, main,false);
main.removeView(main);
main.addView(view);
}

Maybe you could just make your layout invisible if that is the case.
This can be done quite easily programmaticaly:
layout.setVisibility(View.GONE);

According to #ookami.kb's suggestion I should use main.removeAllViews(); instead of main.removeView(main);, that helped me.

Adding a view dynamically in a ClickListener

I am trying to add a View to a RelativeLayout in my OnClickListener.
montrolButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// myParent is a relative layout
// newChild is an ImageView
myParent.addView(newChild);
requestLayout();
}
});
I have looked at the HierarchyViewer, I don' see my new child being added.
Can you please tell me if I miss anything?

I just tried the very same code and it works as it should. There could be an issue with your variable myParent which is not the element you expect it to be.
Also I did not have to call requestLayout() for the added view to appear on the screen.
Possibly try to just explicitly get another part of your view and add it there to see what is happening. Also just to try, you may do this:
RelativeLayout rv = (RelativeLayout) this.findViewById(R.id.right3);
ProgressBar iv = new ProgressBar(this);
rv.addView(iv);
to see if there is anything wrong with your image view instead of myParent
In any case it works if both elements are OK - there is nothing else to do in an activity.

Do you set the layout attributes of the new view (image view)?

Adding View to Relative Layout behind an existing view causes screen flicker

I'm trying to insert a View behind another view that is taking up the full screen and then later removing the view in the front to reveal the only remaining view. Functionally, everything is working as expected but the problem is that when I call View.addView() to add the second view, specifying to add it at index 0 so it is behind the first view, the screen flickers. It's almost as if the view is actually getting added in front of the first view for a fraction of a second and then it is hidden again as it is moved behind it.
Here's what I'm doing:
When the Activity is created I add an ImageView to a RelativeLayout and make the RelativeLayout instance the Activity's content view:
protected void onCreate(Bundle bundle) {
super.onCreate(bundle);
m_layout = new RelativeLayout(this);
m_layout.setBackgroundColor(Color.BLACK);
m_splashImage = new ImageView(this);
m_splashImage.setImageResource(R.drawable.splash);
m_splashImage.setScaleType(ScaleType.FIT_XY);
m_layout.addView(m_splashImage,
new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.FILL_PARENT,
RelativeLayout.LayoutParams.FILL_PARENT));
setContentView(m_layout);
}
When the Activity is started, I created and add the GLSurfaceView to the RelativeLayout at index 0, so it is behind the ImageView:
protected void onStart() {
super.onStart();
m_layout.addView(new MyGLSurfaceView(), 0,
new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.FILL_PARENT,
RelativeLayout.LayoutParams.FILL_PARENT));
}
Later, after all of the loading is done and the GLSurfaceView is ready to continuously render,
the splash ImageView is removed and cleaned up.
public void hideSplashScreen() {
if (m_splashImage != null) {
m_layout.removeView(m_splashImage);
m_splashImage = null;
}
}
Is there a better way to do this that doesn't require creating the GLSurfaceView before the onStart() is called?

Have you tried using view.setVisibility(View.GONE) on of the view that you adding behind? Of course before you are adding it.