What does using a "." without an object in Android (or java) mean?

Question

I am not sure but this is probably a java question and not specific to android. In the Android SDK, when I type in a "." at a blank line, it shows me an options menu:

The MyThread class is declared inside the MainActivity class (which extends Activity and implements some other interfaces for the UI). Normally this menu shows up when "." operator is placed after an object, and it shows the member data and functions declared in the class, of which that object is an instance of. However, there is no object here but still it is showing me this menu. Why is it doing that? If I just select a function and place it here, which object's function is it that gets executed?

Also, placing this "." in position 1 shows me an error. Position 1 is just inside the MainActivity class. Why does it show error here, but not at the position shown in the picture?

Answer 1

In eclipse default settings, the dot calls content assist, there'll be methods popup which can be overwrite from the father class, which is Thread in your code, and from all class extends Object, there're methods from Object class can be overwrite, you may see that from the grey comment after the method name.

Answer 2

Feature is called auto complete. Most IDE's support that.

What does using a “.” without an object in Android (or java) mean?

Your question is a bit ambiguous. You have just placed a dot and IDE tried to auto complete it. But in general even in a black line if you execute auto complete(Ctrl + space) in eclipse/Intellij IDEA you will get the same popup.

Generally dot means accessing a static variable or invoking a method. So IDE gives possible drop down.