Called by the Transition framework when its timer ticks to pass in the time (in ms) since the transition started. You should return (in an out parameter) the percentage movement towards the destination value for the time passed in. Note: this does not need to be a smooth transition from 0% to 100. You can overshoot with values greater than 100 or undershoot if you need to (for example, to have some form of "elasticity"). The percentage should be returned as (for example) 0.1 for 10. You should return (in an out parameter) whether the transition has completed. (This may not be at the same time as the percentage has moved to 100.)

void onTimer( 
   int iTime,
   out double dPercentage,
   out bool bCompleted
)

void onTimer( 
   int iTime,
   [Out] double dPercentage,
   [Out] bool bCompleted
)