Am 21.09.2015 um 13:24 schrieb Riccardo Mottola <[email protected]>:
> Hi, > > I noticed that when I define a NSStepper with a wide range (e.g. 1000) and a > float increment of 0.1, after a dozen of "increments" things go adrift with a > rounding error.. eg 5.10000001 instead of 5.1 > > I have tested on Mac 10.5 and PPC and get different errors (e.g. 5.099999998) > but the problem is the same, it is nto a GS bug, but probably a problem on > how the internals are handled. > > What solution is possible? I have both a textfield and a stepper that should > interact. > I was thinking of just getting the "action" of the Stepper and then keeping a > variable of mine with, eventually a different precision or that does other > rounding tricks. > However, how can I know if increment or decrement have been clicked? Is there > a trick? can I reliably put an action on the two arrows but action was > desired by the user? > > A really crude workaround would be to use just a very high number in the > stepper, integer values and not-wrapping and thus compating old and new value > to know if "+" or "-" were the choice, but looks pretty much a hack. You could try to attach an action method and each time the stepper changes, round the position up/down to the precision you expect. This should avoid to accumulate rounding errors (float/double are not infinite precision). Something like [stepper setDoubleValue:rint([stepper doubleValue]*10.0)/10.0]; Use 100.0 if you have 0.01 steps etc. So basically the factors should be the step size. BR, Nikolaus > > Thanks - Riccardo > > > > _______________________________________________ > Discuss-gnustep mailing list > [email protected] > https://lists.gnu.org/mailman/listinfo/discuss-gnustep _______________________________________________ Discuss-gnustep mailing list [email protected] https://lists.gnu.org/mailman/listinfo/discuss-gnustep
