Could you please help me which class and API i have to use to code the following scnerio:

- I want to load one url but i want to mask all the contents of that url. And i have to provide my text boxes and buttons.
- If user clicks My button i have to supply that click action to url button loaded in webview background to do appropriate action.

For example:
- I have to load gmail.com but i don't want UI of gmail.com. I will provide my simple UI with username,password and login button.
- If user clicks my UI button i will pass that to gmail.com "login" button. It has to open the inbox of that particular user.

Could you please help which class and APIs i have to use for this example?

Hope you will help me