I need to design a custom text view that displays logs that my application produces. Logs have a specific packed binary format, each entry includes a number of fields besides an actual string (log level, date, source). Now these logs can be huge, hundreds of megabytes of data. I need to implement features such all quick filtering based on message type/source, searching, control over memory layout, etc. Since NSTextView supports most of these features i decided to start from there.
I obviously need my custom text storage to provide access to my packed log format, to load new strings on demand when user scrolls the log view window. I also need to selectively display lines of logs based on current active filters (display only warnings for example) without reloading the whole text into the view again, just filtering out the lines as they are displayed.
I have looked at NSTextStorage and it advises to overload -string, which does not exactly fits the purpose. Could anyone please give a couple of pointers to guide my further research? I am relatively new to cocoa’s text handling.
Not a direct answer to your question, but a possible alternative good enough for Apple:
Why not do as Console.app does with proper system logs? Each log entry (though it might be multiple lines) starts with a very specific format. Console.app uses an outline view (an entry has a child row if the line is too long for the table row to keep all entries the same size for easy perusal). Check it out in /Applications/Utilities/Console.app under a standard log.
The benefits: simple selection of entire entry, very easy search filtering, alternating row colors make individual entries easier to see, you could use variable row height to show the whole message if you didn’t like the truncated / disclosure approach.