Controls are slided in by animating translationX from the actor's
width to 0; however as _updateTranslation() will skip the animation
when the property is already at its target value and 0 happens to be
the initial value of translationX, the initial animation is skipped.
Fix this by initializing translationX to undefined, which will always
differ from a valid target value.
_init: function(params) {
this._slideX = 1;
- this._translationX = 0;
+ this._translationX = undefined;
this._direction = SlideDirection.LEFT;
this.parent(params);