I am facing a problem when using qwtdirectpainter in my application..I am drawing my curve using qwtdirectpainter class..When the curve is getting plotted,if by chance a tooltip appears on the curve from other applications,and if i remove the tooltip then i find that the curve is getting disconnected...For example i am having many windows open on my desktop..I am plotting a curve on qwtplot widget which is the maximised window.If i place my mouse cursor on any minimised window,then we know that a tooltip describing that window appears..If by chance that tooltip covers the curve i am plotting and then after if i move the mouse cursor so that tooltip disappears,then i find that the curve which is getting plotted gets disconnected and plotting gets continued with some shift..The same observation i had when using the oscilloscope example...How to solve this problem?Thank you...