Recycler源码解读＜二＞ fill 方法分析

最新推荐文章于 2022-10-23 10:16:10 发布

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最新推荐文章于 2022-10-23 10:16:10 发布 · 319 阅读

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深入剖析LinearLayoutManager中的fill方法，理解RecyclerView如何通过此方法填充布局，包括处理滑动引起的View回收，以及布局过程中对空间的计算与分配。

跟大家说明下，我分析的源码是LinearLayoutManager 里面的fill方法，Recycler系列都是采用这个布局里面的方法。

首先我提出了fill方法的所有源码。

int fill(RecyclerView.Recycler recycler, LayoutState layoutState,
RecyclerView.State state, boolean stopOnFocusable) {
// max offset we should set is mFastScroll + available
final int start = layoutState.mAvailable;
if (layoutState.mScrollingOffset != LayoutState.SCROLLING_OFFSET_NaN) {
// TODO ugly bug fix. should not happen
if (layoutState.mAvailable < 0) {
layoutState.mScrollingOffset += layoutState.mAvailable;
}
recycleByLayoutState(recycler, layoutState);
}
int remainingSpace = layoutState.mAvailable + layoutState.mExtra;
LayoutChunkResult layoutChunkResult = mLayoutChunkResult;
while ((layoutState.mInfinite || remainingSpace > 0) && layoutState.hasMore(state)) {
layoutChunkResult.resetInternal();
layoutChunk(recycler, state, layoutState, layoutChunkResult);
if (layoutChunkResult.mFinished) {
break;
}
layoutState.mOffset += layoutChunkResult.mConsumed * layoutState.mLayoutDirection;
/**
* Consume the available space if:
* * layoutChunk did not request to be ignored
* * OR we are laying out scrap children
* * OR we are not doing pre-layout
*/
if (!layoutChunkResult.mIgnoreConsumed || mLayoutState.mScrapList != null
|| !state.isPreLayout()) {
layoutState.mAvailable -= layoutChunkResult.mConsumed;
// we keep a separate remaining space because m