objective-cnsviewsetneedsdisplay

How to make NSView display immediately while in loop?

I have a loop that iterates 1 million times doing some calculations on a dataSet.

To show the progress of these calculations, I'd like to display the dataSet in an NSView periodically, say, every 10,000 loop iterations, then pause for 1 second so I can see the dataSet displayed in its current state.

for(j=0; j<1000000; j++)
{
   ...do some calculations on dataSet

   if(j%10000 == 0){
      [myView display] //[myView drawRect:] will show current state of dataSet
   }

   ... pause for a second to see the dataSet in myView
}

So in this case I want 10 display updates, roughly 1 every second.

I've tried all sorts of ways, from using NSTimers to [NSThread sleepForTimeInterval], but so far I am only seeing the view updated after the loop has finished.

It doesn't matter if the thread/UI is blocked, as it's only to visualize my own calculations.

Solution

  • For sleep 

    usleep(useconds_t)

    example for one second

    usleep(1000000);