For my application , I'm planning to have a design as this:
http://img811.imageshack.us/img811/7045/problemel.png
-Design needs to have a title bar which is indeed the action bar in android. To overcome the compatibility issues, I used the sherlock action bar which is said to support older versions that dont have action bars. I havent tested yet for the older devices however.
-As far as I know, for navigation , we could rather use tabbed or dropdown list methods. I want to have constant tabs for every page in my app to stand below the page. This reflects the tabbed action bar, however I want it below not just under the action bar. I don't know how but youtube application somehow has it in the middle of the screen (if it's not a custom view). So how do we have tabs positioned in the bottom of the page?
-Also I want to have another menu, whose items depend on the page it's on. But the apperance will be the same for every page. In the picture on the left this menu has buttons as "Bt 1" ,"Bt 2". I dont want to repeat the same xml for every activity page, but I'm not sure how to achieve it without repeating. If the action bar allowed using both navigation tabs and the drop down list, I could put the items of this menu in the dropdown list just as the picture on the right (onto the gray button). But I guess it does not?!
Therefore I have to repeat the menu xml code in every page or is there another smart way?
Any advice will be appreciated.
This can be achieved not with tabs but by adding items to a linear_layout with a gravity of bottom but it is a bad practice as @D_Steve595 stated and should be avoided in android designs.