Use SliverList and cache content height #1802
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domesticmouse
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May 11, 2023
HansMuller
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May 11, 2023
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| // Based on the fact that the list content is fixed, we cache | ||
| // the height of the content during the first-time scrolling. | ||
| // The cached height can be used to override | ||
| // `SliverChildDelegate.estimateMaxScrollOffset`, to avoid a shaking scrollbar. |
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| // Based on the fact that the list content is fixed, we cache | |
| // the height of the content during the first-time scrolling. | |
| // The cached height can be used to override | |
| // `SliverChildDelegate.estimateMaxScrollOffset`, to avoid a shaking scrollbar. | |
| // If the content of a CustomScrollView does not change, then it's | |
| // safe to cache the heights of each item as they are laid out. The | |
| // sum of the cached heights are returned by an override of | |
| // `SliverChildDelegate.estimateMaxScrollOffset`. The default version | |
| // of this method bases its estimate on the average height of the | |
| // visible items. The override ensures that the scrollbar thumb's | |
| // size, which depends on the max scroll offset, will shrink smoothly | |
| // as the contents of the list are exposed for the first time, and | |
| // then remain fixed. |
| } | ||
| } | ||
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| // Based on the fact that the list content is fixed, we cache |
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Fixes #1694
This PR is to fix the shaking scrollbar problem. We replace the
ListViews withCustomScrollViewand cache the content height to provide a better estimation for the max scroll offset.Same changes are applied to both Material 3 demo in the root directory and the M3 demo in the
/experimental/Screen.Recording.2023-05-10.at.4.05.27.PM.mov
two_cols.mov
Pre-launch Checklist
///).