2D Left Right button mobile control

Unity Engine
1

Hello,

Im stuck! I have a 2d Mobile platform game with a left arrow and a right arrow on a canvas that works on a iPhone using the Pointer Up and Pointer down event triggers. But I want the user to press one of the buttons and slide their finger into the other button area without releasing their finger to change the direction of the player on screen. Could anyone point me in the correct direction.

Thank you.

2

maybe with pointer enter it works without needing to release,
http://docs.unity3d.com/ScriptReference/UI.Selectable.OnPointerEnter.html

also in unity standard assets there is mobile joystick examples. (cross platform controller)