Android Question activity design: apply custom font to all activity's text views

Hi, All

Is it possible ? Custom .ttf or .otf font file in the asset should be used.
1) In a loop to update the font of all texts.
2) If some listviews are dynamically updated after user interaction - it must be updated during the listview populating ?

Or maybe is it possible to apply the asset font to whole the activity or whole app by some layout\manifest settings ?