How can I make a body rotatable but not movable in box2d?

Question

I need to make a body to not move around, like a static body, but i do need it to be rotatable, is there any way to do so?

Answer 1

Create normal dynamic body and static body - put them in the place when you want to have rotatable body lay and joint them using RevoluteJoint - it is kind of joint that you can imagine as a 'pin'

BodyDef dynamicBodyDef, staticBodyDef;
//define type, position of bodies...

Body dynamicBody = world.createBody(dynamicBodyDef);
Body staticBody= world.createBody(staticBodyDef);

RevoluteJointDef jointDef = new RevoluteJointDef();
jointDef .bodyA = dynamicBody;
jointDef .bodyB = staticBody;

world.createJoint(jointDef );

You can define if bodies can collide, what is the maximum angle etc - take a look at RevoluteJointDef class definition