Re: Why is NSTableView scrolling in Cocoa apps so slow?
Re: Why is NSTableView scrolling in Cocoa apps so slow?
- Subject: Re: Why is NSTableView scrolling in Cocoa apps so slow?
- From: Henk Kampman <email@hidden>
- Date: Thu, 06 Sep 2001 12:44:09 +0200
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From: Andreas Monitzer <email@hidden>
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Date: Wed, 5 Sep 2001 14:24:12 +0200
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To: Henk Kampman <email@hidden>
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Cc: <email@hidden>
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Subject: Re: Why is NSTableView scrolling in Cocoa apps so slow?
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On Wednesday, September 5, 2001, at 02:08 , Henk Kampman wrote:
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> To get started with Cocoa I decided to port an existing Powerplant
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> application.
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> Everthing works fine but thumb scrolling speed is incredibly slow compared
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> to the Carbon Powerplant version running on MacOSX.
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> Even a simple NSTableView with 1 column and static data scrolls slowly!
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> It looks as if the actual displayed content has little effect on the
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> performance so there must be something else going on.
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On scroll, NSTableView permanently polls the data source for getting
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information (count, item at line x). Maybe that method is too slow.
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andy
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--
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Discussion forthcoming.
During live scrolling I get at max 2 updates per second.
The NSTableView has 40 visible rows,in other words getting and drawing 40
(short) strings takes aprox. 0.5 seconds.
Thats not slow, thats pathetic!
The Carbon application running on the same hardware (G4/400) and MacOSX is
magnitudes faster.
So this can't be a Quartz issue.
I've also noticed that other Cocoa applications using (large) tables have
the same performance problems with live scrolling.
There must something wrong with the way NSTableView processes/generates
update events during live scrolling.
Any ideas?
Henk