On Sep 27, 2015, at 10:42 , Ben <ben_cocoa_dev_l...@yahoo.co.uk> wrote: > > - Not all strings to be drawn at once, a scroll view is being used and I am > using responsive scrolling to pre-draw areas. The problem occurs when quickly > scrolling a large distance
I think your answer is in this statement. Assuming you’re drawing the strings in drawRect of a custom view, and the size and position of the grid cell containing each string doesn’t depend on the metrics of any other string, then the cost of this kind of interface is the number of strings you can *see* at once (less than 50 surely), not the number of strings in your data model. Responsive scrolling may make the smaller number a bit larger, but if you’re getting performance problems from this, you’re likely doing something wrong. But … > The problem occurs when quickly scrolling a large distance There it is, really. What I said before applies only when the scrolled view isn’t scrolling. When it is, you can *see* many more strings at essentially the same time. What’s the answer to this question: If you quickly scroll across 10,000 strings, how many strings is your drawRect drawing? 10,000? Less? More? You need to do some analysis to find out what you’re actually doing. Are you using the dirtyRect parameter of drawRect to limit which strings you draw? Are you using ‘getRectsBeingDrawn:count:’ or ‘needsToDrawRect:’ to limit drawing even further? Have you tried using a table view? Ultimately, if your drawing technique can’t keep up with fast scrolling, you’re going to have to *stop* drawing when it starts to lag, and catch up when scrolling slows or stops. P.S. You didn’t say whether this is OS X or iOS. I think responsive scrolling is OS X only, so I’m guessing that’s the platform. _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
