meliorence/react-native-snap-carousel

Adjust index if data item is removed

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#157 建立於 2017年9月21日

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 (17 留言) (6 反應) (0 負責人)JavaScript (10,045 star) (2,223 fork)batch import
*help wanted

描述

I want to use this component to let a user navigate through a (potentially endless) stream of items and as such I am adding new items to the data array as the user nears the end of the list and this works just perfectly. Obviously though I can't just keep adding items without removing older ones forever as this will exhaust memory at some point.

Removing items from the start of the data array seems to work pretty well except for the fact that it seems to act very strange with the index system. The problem is that the index doesn't change and after navigation there is a huge jump to the position of the old index+1. It would be nice if the component could automatically deal with this or provide me with a way to decrement the index without visually navigating.

貢獻者指南

技術棧
javascriptreact native
領域
mobilefrontend
議題類型
feature
難度面向新貢獻者的預計實作難度，1 表示很小改動，5 表示專家級工作。
3
預計時間有經驗貢獻者完成調查、實作、測試並準備 pull request 的粗略時間範圍。
half day
活動狀態議題目前的可參與程度：新鮮、活躍、陳舊、阻塞或等待維護者輸入。
stale
清晰度議題是否清楚說明預期改動、驗收標準和下一步。
clear
前置要求
JavaScriptReact NativeState managementCarousel logic
新手友善度1-100 的估計分數，表示該議題對首次貢獻者的友善程度。
40
研究方向
Examine the component's source code in index.js (or main file) to understand how the current index is managed and how data prop changes are handled. Look for existing logic that updates the index when data changes (e.g., componentDidUpdate or useEffect). The issue suggests that when items are removed from the start, the index should decrement accordingly. Investigate if there is an API to programmatically set the index without animation (e.g., snapToItem with animated false). Check if there are any closed PRs or issues that discuss similar index adjustments. Potential solution: In the data prop change handler, if the number of items decreased, adjust the current index by the difference if the removed items were before the current index. Ensure that the visual position is updated without animation.