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https://issues.apache.org/jira/browse/FLEX-34821?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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After24 updated FLEX-34821:
---------------------------
Description:
This is an experimentation on the flex Scroller compoennt to improve the
framerate of the scrolling operations.
This optimization based on the blitting technique.
A new boolean property named cacheViewport is added to the Scroller component.
When cacheViewPort is set to true, all scrolling operations are performed
according to the following cycle :
1 - A bitmap copy of the viewport is made just before the next scrolling
operation (large viewports are cached in multiple tiles if necessary)
2 - When the user starts a scrolling operation, the actual viewport is replaced
by its bitmap version and the scrolling is executed by drawing the viewport
according to its verticalScrollPosition and horizontalScrollPosition properties.
3 - At the end of the scroll operation, the bitmap viewport is replaced by its
actual version.
4 - Between each scrolling operations, when the user interacts with the
viewport content, a process mark as 'dirty' every regions of the viewport that
are likely to have changed during those interactions. Every dirty region is
redrawn before the next scrolling operation.
Pros :
- 60 FPS scrolling, even on old devices.
- Performance is no longer dependant on the viewport complexity.
- Can be used with the list component if it contains a moderate number of rows
(useVirtualLayout must be set to false though)
Cons :
- There is a slight lag (dependant on the device processor) during the viewport
rasterization and the process of redrawing every dirty regions.
- Doesn't support virtualized layouts.
- Animated elements of the viewport freezes during scrolling operations.
- Render mode must be set to <renderMode>gpu</renderMode> on the current
version.
- Depending on its dimensions, the viewport rasterization process can consume
large amounts of memory.
A demo application can be downloded on the android play market here :
https://play.google.com/store/apps/details?id=air.fr.after24.ViewportCacheDemo
Source code is attached.
> Improvement of the scroller perfomances on mobile devices
> ---------------------------------------------------------
>
> Key: FLEX-34821
> URL: https://issues.apache.org/jira/browse/FLEX-34821
> Project: Apache Flex
> Issue Type: Improvement
> Reporter: After24
>
> This is an experimentation on the flex Scroller compoennt to improve the
> framerate of the scrolling operations.
> This optimization based on the blitting technique.
> A new boolean property named cacheViewport is added to the Scroller
> component. When cacheViewPort is set to true, all scrolling operations are
> performed according to the following cycle :
>
> 1 - A bitmap copy of the viewport is made just before the next scrolling
> operation (large viewports are cached in multiple tiles if necessary)
> 2 - When the user starts a scrolling operation, the actual viewport is
> replaced by its bitmap version and the scrolling is executed by drawing the
> viewport according to its verticalScrollPosition and horizontalScrollPosition
> properties.
> 3 - At the end of the scroll operation, the bitmap viewport is replaced by
> its actual version.
> 4 - Between each scrolling operations, when the user interacts with the
> viewport content, a process mark as 'dirty' every regions of the viewport
> that are likely to have changed during those interactions. Every dirty region
> is redrawn before the next scrolling operation.
> Pros :
> - 60 FPS scrolling, even on old devices.
> - Performance is no longer dependant on the viewport complexity.
> - Can be used with the list component if it contains a moderate number of
> rows (useVirtualLayout must be set to false though)
> Cons :
> - There is a slight lag (dependant on the device processor) during the
> viewport rasterization and the process of redrawing every dirty regions.
> - Doesn't support virtualized layouts.
> - Animated elements of the viewport freezes during scrolling operations.
> - Render mode must be set to <renderMode>gpu</renderMode> on the current
> version.
> - Depending on its dimensions, the viewport rasterization process can consume
> large amounts of memory.
> A demo application can be downloded on the android play market here :
> https://play.google.com/store/apps/details?id=air.fr.after24.ViewportCacheDemo
> Source code is attached.
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