You are looking at ng-focus and ng-blur.
<input type="text" style="border: none" ng-model="model" ng-focus="A()" ng-blur="B()">
On a side note, use css classes instead of inline styles.. 🙂
Or just call the same method with argument and set the value acc:-
<input type="text" style="border: none" ng-model="model" ng-focus="A(true)" ng-blur="A(false)">