How to invoke context sensitive menu on Android?

I will develop an app to run on a small Android slate PC. Most of the screen is taken up with a string grid. The original idea was to highlight one or more rows of the grid then click an on-screen button to perform an operation.

I am running out of space for buttons, so I immediately thought of a right-click context menu.

BUT, I can't guarantee that the Android device chosen will have "mouse buttons". What if it is fully touch screen, with no mouse-like device?

Maybe I am worrying about nothing, but I need to get coding now and the h开发者_如何学JAVAardware won't be chosen - by someone else - for a while yet. So, how woudl I best invoke multiple functionalities on the string grid?

I can see that I might have to rethink my ideas about GIUs in general to cover things like that and the much smaller screen size, etc Any reading recommendations, whether URLs or book?

the standard ui convention for android is to emulate a right click context action with a long press event. If the user highlights a string, and Presses and holds on that section, then a context menu could appear with a list of options.