null if it has not been loaded\n * yet.\n *\n * \n * If this method has been called for a specific position and returned null, then\n * {@link ViewCallback#onItemLoaded(int)} will be called when it finally loads. Note that if\n * this position stays outside of the cached item range (as defined by\n * {@link ViewCallback#extendRangeInto} method), then the callback will never be called for\n * this position.\n *\n * @param position Item position.\n *\n * @return The data item at the given position or null if it has not been loaded\n * yet.\n */\n @Nullable\n public T getItem(int position) {\n if (position < 0 || position >= mItemCount) {\n throw new IndexOutOfBoundsException(position + \" is not within 0 and \" + mItemCount);\n }\n T item = mTileList.getItemAt(position);\n if (item == null && !isRefreshPending()) {\n mMissingPositions.put(position, 0);\n }\n return item;\n }\n\n /**\n * Returns the number of items in the data set.\n *\n *
\n * This is the number returned by a recent call to\n * {@link DataCallback#refreshData()}.\n *\n * @return Number of items.\n */\n public int getItemCount() {","sourceCodeStart":138,"sourceCodeEnd":174,"githubUrl":"https://github.com/DrKLO/Telegram/blob/45ab8f4308496e1f01026a97fcdb0d58a5274474/TMessagesProj/src/main/java/androidx/recyclerview/widget/AsyncListUtil.java#L138-L174","documentation":"AsyncListUtil lazily loads data items in background tiles and exposes getItem(position) to the UI thread. mItemCount is the total data set size reported by the DataCallback.refreshData contract. Requesting a position < 0 or >= mItemCount is out of contract because the underlying tile grid only covers [0, mItemCount). The exception is a hard bounds check — there is no valid item outside that range, so the call cannot return data and fails fast instead of returning a wrong value.","triggerScenarios":"The RecyclerView adapter getItemCount() returns a larger value than the AsyncListUtil mItemCount (size mismatch between adapter and the AsyncListUtil); a position derived from a stale cursor after the data set changed; off-by-one when mapping a scroll position to an item index.","commonSituations":"Calling refresh() on the AsyncListUtil without also updating the adapter count; the adapter and DataCallback disagree on total count after a background refresh; rapid scroll past the end during a data swap.","solutions":["Ensure RecyclerView.Adapter.getItemCount() and AsyncListUtil.DataCallback.refreshData report the same total count, and call asyncListUtil.refresh() whenever the count changes.","Guard the call site: if (position >= 0 && position < asyncListUtil.getItemCount()) before getItem.","Update the adapter's itemCount atomically with the AsyncListUtil refresh to avoid stale positions."],"exampleFix":"// before\nString item = asyncListUtil.getItem(position); // may throw if stale\n\n// after\nif (position >= 0 && position < asyncListUtil.getItemCount()) {\n String item = asyncListUtil.getItem(position);\n} else {\n item = null;\n}","handlingStrategy":"validation","validationCode":"// Bounds-check before getItem\npublic