added a function to use all viewable area
Revert "added a function to use all viewable area"

This reverts commit bf0510d36ae1facd9b2ab4b9167ff11c8a0e3522.
Revert "Revert "added a function to use all viewable area""

This reverts commit eaecb820467e5869015e274627e37983cae1cf9e.