ToProgress | A lightweight top progress bar | Runtime Evironment library

I do not get the list out of the background thread. When I access the list in the UI (different thread), I'll get this result:

You get the list out of the background thread, what causes problems is accessing the properties of the individual list items.

Most likely, those items are ui objects themselves and have to be created on the ui thread. So you have to dispatch each new back to the ui thread, which essentially leaves adding them to the list as only job for the background task, which will hardly be cpu-bound, so just drop the background thread.

Can't you put the pausing to the completion handler of the present, like:

Try this code i am not sure this will help in your case

Hold tight this involves some math!

Assuming the centre of your circle is (0, 0). Say you have a point (x, y) lying on the circumference, you can use the atan2 or arctan2 function to get the angle (in radians; radians being what you want as UIBezierPath uses radians) the point lies with respect to the centre of the circle. So, with this angle, you know where on the circumference of your circle the user has touched (call it touch angle). You can use this as your endAngle on UIBezierPath.

Note: If your circle's centre is not (0, 0) but is (x1, y1), compensate by subtracting the difference from the touch points (x, y) i.e, your new points are (x - x1, y - y1)

If you want a percentage of how much of the circumference the point covers from 0 rads. You can use the formula percentage = (touch angle*(in rads)* * 100)/2π).

More on atan2/arctan2

You can calculate your touch angle using the formula touch angle = tan^(-1)(y/x) aka touch angle = arctan2(y,x). Where (x, y) are the points the user has touched on the circumference.

Example and explanation (Edit)

Okay phew, after some research, I figured it out. Take a look at this code, notice the touchesBegan(_ ... function.