{"record":{"id":"065e83e512d3bb21","repo":"DrKLO/Telegram","slug":"item-at-position-requires-spans-but-gridlayo","errorCode":null,"errorMessage":"Item at position {} requires {} spans but GridLayoutManager has only {} spans.","messagePattern":"Item at position (.+?) requires (.+?) spans but GridLayoutManager has only (.+?) spans\\.","errorType":"exception","errorClass":"IllegalArgumentException","httpStatus":null,"severity":"error","filePath":"TMessagesProj/src/main/java/androidx/recyclerview/widget/GridLayoutManager.java","lineNumber":541,"sourceCode":"        // where they may have a header row which should be laid out according to children.\n        if (flexibleInOtherDir) {\n            updateMeasurements(); //  reset measurements\n        }\n        final boolean layingOutInPrimaryDirection =\n                layoutState.mItemDirection == LayoutState.ITEM_DIRECTION_TAIL;\n        int count = 0;\n        int consumedSpanCount = 0;\n        int remainingSpan = mSpanCount;\n        if (!layingOutInPrimaryDirection) {\n            int itemSpanIndex = getSpanIndex(recycler, state, layoutState.mCurrentPosition);\n            int itemSpanSize = getSpanSize(recycler, state, layoutState.mCurrentPosition);\n            remainingSpan = itemSpanIndex + itemSpanSize;\n        }\n        while (count < mSpanCount && layoutState.hasMore(state) && remainingSpan > 0) {\n            int pos = layoutState.mCurrentPosition;\n            final int spanSize = getSpanSize(recycler, state, pos);\n            if (spanSize > mSpanCount) {\n                throw new IllegalArgumentException(\"Item at position \" + pos + \" requires \"\n                        + spanSize + \" spans but GridLayoutManager has only \" + mSpanCount\n                        + \" spans.\");\n            }\n            remainingSpan -= spanSize;\n            if (remainingSpan < 0) {\n                break; // item did not fit into this row or column\n            }\n            View view = layoutState.next(recycler);\n            if (view == null) {\n                break;\n            }\n            consumedSpanCount += spanSize;\n            mSet[count] = view;\n            count++;\n        }\n\n        if (count == 0) {\n            result.mFinished = true;","sourceCodeStart":523,"sourceCodeEnd":559,"githubUrl":"https://github.com/DrKLO/Telegram/blob/45ab8f4308496e1f01026a97fcdb0d58a5274474/TMessagesProj/src/main/java/androidx/recyclerview/widget/GridLayoutManager.java#L523-L559","documentation":"GridLayoutManager assigns each item a span size via SpanSizeLookup.getSpanSize (default 1). During fill, it walks positions until the row/column span budget (mSpanCount) is consumed. If a single item's spanSize exceeds the total mSpanCount, the item can never fit in any row, so the layout is mathematically impossible and GridLayoutManager throws rather than entering an infinite loop or mis-rendering. The classic case is a 'full-width' header item with spanSize = spanCount while the grid was configured with a smaller spanCount than the lookup expects.","triggerScenarios":"A SpanSizeLookup that returns spanCount for headers but the GridLayoutManager was created with a smaller spanCount (e.g. 3 vs lookup assuming 4); dynamic span count change (rotation, tablet) without recomputing span sizes; a lookup returning a hardcoded number larger than the configured span count.","commonSituations":"Mixed-item feeds (headers + grid items) where the header span size was hardcoded; rotation changing spanCount from 3 to 2 but SpanSizeLookup still returns 3; tablet/master-detail where span count varies but span sizes do not.","solutions":["Make SpanSizeLookup.getSpanSize return values bounded by the current GridLayoutManager.getSpanCount(), e.g. return getSpanCount() for full-width items.","When changing spanCount at runtime, ensure the SpanSizeLookup logic scales with it.","Use a header SpanSizeLookup that returns spanCount (the dynamic total), not a hardcoded number."],"exampleFix":"// before\nglm.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {\n    @Override public int getSpanSize(int position) {\n        return isHeader(position) ? 4 : 1; // throws if spanCount < 4\n    }\n});\n\n// after\nfinal GridLayoutManager glm = ...;\nglm.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {\n    @Override public int getSpanSize(int position) {\n        return isHeader(position) ? glm.getSpanCount() : 1;\n    }\n});","handlingStrategy":"validation","validationCode":"// Bound span size to the current span count\nfinal GridLayoutManager glm = ...;\nglm.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {\n    @Override public int getSpanSize(int position) {\n        if (isHeader(position)) return glm.getSpanCount(); // dynamic\n        int s = itemSpanSize(position);\n        return Math.min(Math.max(1, s), glm.getSpanCount());\n    }\n});","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Return glm.getSpanCount() for full-width items, not a hardcoded number.","Re-evaluate span sizes whenever spanCount changes (rotation, tablet).","Clamp any external span size to [1, spanCount]."],"tags":["recyclerview","gridlayoutmanager","spansize","configuration","layout"],"backgroundTag":null,"analyzedSha":"45ab8f4308496e1f01026a97fcdb0d58a5274474","analyzedAt":"2026-08-14T05:19:30.815Z","schemaVersion":2},"datasetVersion":"2026-08-14T10:17:34.591Z"}