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by CarVac
3803 days ago
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Interesting. What exactly is each 'widget' when you say there are 100+ widgets? Each overall feature, or each Item within the feature? In my photo editor I have a histogram of how many photos you've taken each day: http://i.imgur.com/7yAYsP9.png The histogram is actually a ListView, and each delegate is actually not just the bar for each date, but also the background color, the highlight color for the current date, and the date text that's above each bar. Using model updating, it responds nearly instantly even though there are a thousand days in the view, and the source data is a big ol' SQLite query with C++ postprocessing. I don't know if that's helpful to you, though. Would that count as one widget in your parlance? |
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ListViews are optimized for display of lists, obviously, so they generally instantiate only visible elements in the view, and delegates do not even undergo geometry negotiation so they're a bit lighter than a regular widget.
Still, if you do visualization or animation, the UI must respond within 1ms in order not to be noticeable, and that's very hard to attain with Qt5.
I doubt people using QML on mobile devices really understand the issue either, since when mobile developers speak of "animations" they generally mean some random transition of the UI itself. Often, the operation is not even performed in the background, but rather simply sequenced (so that the animation appears to be smooth, but the actual delay is completely absorbed by the user). In these scenarios, times up to 250ms/300ms might still be felt "instantaneous" as they're shorter than the transition. For me, it's outrageous.