How Android View Hierarchies work

Question

I have a WebView that I would like to expand to fullscreen. The user will interact with it, so it needs to maintain some sort of state when it expands. The ideal process is this:

- Remove WebView from its parent
- Put WebView at the top of the current View hierarchy with `FILL_PARENT` for width and height

Later, I will need the put the WebView back:

- Remove WebView from top of the hierarchy
- Restore the old hierarchy
- Put WebView back where it was with its previous setting for width and height

I know about getRootView, but I don't know how to use it. What's a DecorView?

If anyone has some sample code to accomplish the expanding and collapsing behavior I've described above, I'd be really grateful. Thanks!

Answer 1

Get the root view of the DecorView:

ViewGroup parentViewGroup = (ViewGroup) webView.getRootView().findViewById(android.R.id.content);
View rootview = parentViewGroup.getChildAt(0);

Remove that root view:

parentViewGroup.removeViewAt(0);

Remove the WebView from its parent:

View webViewParent = (View) webView.getParent();
webViewParent.removeView(webView);

Put the WebView at the top of the view hierarchy:

parentViewGroup.addView(webView, 0, new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.FILL_PARENT, RelativeLayout.LayoutParams.FILL_PARENT));

Use your rootview reference to undo the expansion.

The only thing is: I don't know how you're going to restore the layout parameters for rootview.