>> At the moment that the operations are queued, there are some operations in the queue not yet run, and some running. The code that creates the operations doesn't know which ones are needed more urgently (the latest ones), so it can only assign a high priority to all of them, so they all end up with the same (high) priority and so we're back to square one. > > Maintain a mapping of objects to be previewed and the operations that generate those previews. As the user scrolls, figure out which placeholders have been scrolled on/off screen and modify the related operations' priorities appropriately. Altering a running operation's priority won't have an effect.
Potentially you could end up queuing up hundreds (or thousands) of thumbnail generation requests (depending on how many SVG files the user has). If the user was to close the browser to do something else, or switch to another app, you would continue generating those thumbnails. My solution, in an iOS app FWIW, was to cancel the thumbnail generation operations for the thumbnails that scrolled out of view. _______________________________________________ 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
