Is it a violation?

[Rob1968]

4-12-1 A player is in control of the ball when he/she is holding or dribbling a live ball inbounds.
4-12-6 . . . Neither team control nor player control exists during a . . . throw-in . . .

Thus, neither the travel nor dribble rule applies to the thrower, during a throw-in. He/she may touch the ball to the floor in the 3-feet wide area designated as the throw-in spot without penalty. He/she may move his/her feet within that area without penalty. One foot must be on or over that area at the time of releases of the ball, on a pass directly to the playing area. The ball may not touch the floor or structure outside of that area on its path during the throw-in pass.
The 5-second time limit to release the ball on a pass applies.