android - Save instance of dynamically generated views when we switch back and forth between activities

Question

I am inflating a view on button click and the user can add as many views as he likes, all is fine I made it work, but now the problem is when I go back one activity and come again to my dynamically generated activity every single view that was generated is gone. Similar is the case if I go to next activity and come back to the inflated activity. I know about onSaveInstance and onRestoreSaveInstance. But how do I put view information in a bundle in onSaveInstanceState? Please note that my view was generated Dynamically i.e. on button Click and I want to know as of how to preserve the state of my activity. How do you go about it?

Answer 1

I am thinking that you should implement some kind of logic that helps you restore the state of your Views. So you should be designing a class, let say ViewDetail that somehow keeps details about the Views that you are adding.... type, dimension, etc. This class should implement Parcelable so you are able to add it to the bundle.

So you will keep an ArrayList<ViewDetail>, myViews where everytime the user adds a new View you create a new ViewDetail object that you add to your myViews array.

And then save your Views and restore them using those objects:

@Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    //save your view states
    outState.putParcelableArrayList("MY_VIEWS",myViews);
}

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);
    //get the views back...
    myViews=savedInstanceState.getParcelableArrayList("MY_VIEWS");
    //TODO: add the views back to your Activity
}