I'm exploring the examples provided in the download and I've come across the plot examples. There are 2 examples which update the graphic in real time using a timer. That timer is set to 0 to update the graph as fast as possible; unfortunately this hangs window interaction and you'll be unable to move the window, to use the close/minmize/maximize buttons, to resize it, or to make any other interaction with it. Moreover it also locks the cursor on the example window so you'll be unable to even touch the taskbar or to interact with any other application (the cursor actually moves, but won't interact with the other windows/applications).
The solution is pretty simple: use a 1 or higher value instead of 0 to start the timer. While with 0 you'll get around 350 FPS or even more, with 1 and higher you'll get to around 60FPS, but window interaction will be responsive as it should be.
This happens on Windows 7 Professional x64 SP1 and QCustomPlot 1.0.1 on Qt 5.1.1 with MSVC2012 x86 compiler (no OpenGL). I'm not sure if it happens on other OSs or Qt versions too, but probably it does.
So, besides the fact that I wanted to let know people of this little issue, I'd also like to understand what's going on? Why does a timer set to 0 hang the window while a simple 1 solves the issue? And why does the framerate drop (on my system) from 374 FPS to 60FPS when switching from timer(0) to timer(1)?