fix(web): reduce chat timeline scroll twitching and overlap - #1054

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huxcrux wants to merge 6 commits into
pingdotgg:mainfrom
huxcrux:feature/timeline-scroll-stability
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fix(web): reduce chat timeline scroll twitching and overlap#1054
huxcrux wants to merge 6 commits into
pingdotgg:mainfrom
huxcrux:feature/timeline-scroll-stability

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@huxcruxhuxcrux commented Mar 13, 2026•
edited by macroscopeapp Bot
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What Changed

This PR reduces chat timeline scroll twitching and overlap.

Smaller and medium-sized threads now render without virtualization, which removes the late row mounting and remeasurement that were causing visible jumps while scrolling upward. Larger threads still use the standard virtualized path.

The remaining row height estimation is kept only for the cases that still need it:

grouped work/tool rows
assistant messages with changed-files summaries

Fixes#1035
Related to #988, #905, #860

Why

Older rows were being mounted and resized after entering view, which caused the timeline to twitch while scrolling and sometimes contributed to overlap.

Disabling virtualization for the thread sizes users hit most often is the simplest and most reliable fix. It removes the unstable behavior directly while still keeping virtualization for larger threads.

UI Changes

This PR improves chat scroll stability and removes visible upward-scroll twitching in affected threads.

Checklist

  • This PR is small and focused
  • I explained what changed and why
  • I included before/after screenshots for any UI changes
  • I included a video for animation/interaction changes

Note

Improve timeline scroll stability with accurate row height estimation

  • Disables virtualization for short timelines (below MIN_ROWS_TO_ENABLE_VIRTUALIZATION) to avoid measurement overhead when it isn't needed.
  • Adds estimateTimelineWorkGroupHeight in timelineHeight.ts to size work-group rows based on visible entries, chip wrapping, and expansion state.
  • Adds estimateChangedFilesSummaryHeight and estimateTimelineRowHeight in MessagesTimeline.tsx to account for completion dividers and changed-files summaries in assistant message rows.
  • Adds countVisibleTurnDiffTreeNodes in turnDiffTree.ts to compute visible diff-tree node counts based on directory expansion state.
  • Behavioral Change: shouldAdjustScrollPositionOnItemSizeChange now triggers when remaining scroll distance is ≤ AUTO_SCROLL_BOTTOM_THRESHOLD_PX (previously only when greater), fixing auto-scroll near the bottom.

Macroscope summarized 0b7ecce.

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@huxcruxhuxcrux changed the title Feature/timeline scroll stabilityfix(web): reduce chat timeline scroll twitching and overlapMar 13, 2026
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i think the actual fix is to do better, more accurate, estimations and having regression tests (ChatView.browser.tsx) to verify estimate === actual ? I've fixed it couple times but when new UI changes are made and we don't update the estimates it regresses. Need tests to ensure it stays in sync.

@huxcruxhuxcrux mentioned this pull request Mar 14, 2026
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i think the actual fix is to do better, more accurate, estimations and having regression tests (ChatView.browser.tsx) to verify estimate === actual ? I've fixed it couple times but when new UI changes are made and we don't update the estimates it regresses. Need tests to ensure it stays in sync.

I created #1093 to fix the estimation, and is working on another PR implementing tests to avoid this from happening again in the future.

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Chat timeline content overlaps (assistant text + tool call cards stack on top of each other)

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, 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
 blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

Skip to content
fix(web): reduce chat timeline scroll twitching and overlap - #1054
Closed
huxcrux wants to merge 6 commits into
pingdotgg:mainfrom 
huxcrux:feature/timeline-scroll-stability
Closed
fix(web): reduce chat timeline scroll twitching and overlap#1054
huxcrux wants to merge 6 commits into
pingdotgg:mainfrom 
huxcrux:feature/timeline-scroll-stability
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@huxcrux
@huxcruxhuxcrux
commented
Mar 13, 2026•

edited by macroscopeapp
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What Changed
This PR reduces chat timeline scroll twitching and overlap.
Smaller and medium-sized threads now render without virtualization, which removes the late row mounting and remeasurement that were causing visible jumps while scrolling upward. Larger threads still use the standard virtualized path.
The remaining row height estimation is kept only for the cases that still need it:
grouped work/tool rows

assistant messages with changed-files summaries
Fixes#1035

Related to #988, #905, #860
Why
Older rows were being mounted and resized after entering view, which caused the timeline to twitch while scrolling and sometimes contributed to overlap.
Disabling virtualization for the thread sizes users hit most often is the simplest and most reliable fix. It removes the unstable behavior directly while still keeping virtualization for larger threads.
UI Changes
This PR improves chat scroll stability and removes visible upward-scroll twitching in affected threads.
Checklist
  •  This PR is small and focused
  •  I explained what changed and why
  •  I included before/after screenshots for any UI changes
  •  I included a video for animation/interaction changes
Note
Improve timeline scroll stability with accurate row height estimation
  • Disables virtualization for short timelines (below MIN_ROWS_TO_ENABLE_VIRTUALIZATION) to avoid measurement overhead when it isn't needed.
  • Adds estimateTimelineWorkGroupHeight in timelineHeight.ts to size work-group rows based on visible entries, chip wrapping, and expansion state.
  • Adds estimateChangedFilesSummaryHeight and estimateTimelineRowHeight in MessagesTimeline.tsx to account for completion dividers and changed-files summaries in assistant message rows.
  • Adds countVisibleTurnDiffTreeNodes in turnDiffTree.ts to compute visible diff-tree node counts based on directory expansion state.
  • Behavioral Change: shouldAdjustScrollPositionOnItemSizeChange now triggers when remaining scroll distance is ≤ AUTO_SCROLL_BOTTOM_THRESHOLD_PX (previously only when greater), fixing auto-scroll near the bottom.
Macroscope summarized 0b7ecce.
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Feature/timeline scroll stabilityfix(web): reduce chat timeline scroll twitching and overlapMar 13, 2026
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i think the actual fix is to do better, more accurate, estimations and having regression tests (ChatView.browser.tsx) to verify estimate === actual ? I've fixed it couple times but when new UI changes are made and we don't update the estimates it regresses. Need tests to ensure it stays in sync.
@huxcruxhuxcrux
mentioned this pull request
Mar 14, 2026
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closed this
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ContributorAuthor
i think the actual fix is to do better, more accurate, estimations and having regression tests (ChatView.browser.tsx) to verify estimate === actual ? I've fixed it couple times but when new UI changes are made and we don't update the estimates it regresses. Need tests to ensure it stays in sync.
I created #1093 to fix the estimation, and is working on another PR implementing tests to avoid this from happening again in the future.
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Chat timeline content overlaps (assistant text + tool call cards stack on top of each other)


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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
fix(web): reduce chat timeline scroll twitching and overlap - #1054
Closed
huxcrux wants to merge 6 commits into
pingdotgg:mainfrom 
huxcrux:feature/timeline-scroll-stability
Closed
fix(web): reduce chat timeline scroll twitching and overlap#1054
huxcrux wants to merge 6 commits into
pingdotgg:mainfrom 
huxcrux:feature/timeline-scroll-stability
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@huxcrux
@huxcruxhuxcrux
commented
Mar 13, 2026•

edited by macroscopeapp
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What Changed
This PR reduces chat timeline scroll twitching and overlap.
Smaller and medium-sized threads now render without virtualization, which removes the late row mounting and remeasurement that were causing visible jumps while scrolling upward. Larger threads still use the standard virtualized path.
The remaining row height estimation is kept only for the cases that still need it:
grouped work/tool rows

assistant messages with changed-files summaries
Fixes#1035

Related to #988, #905, #860
Why
Older rows were being mounted and resized after entering view, which caused the timeline to twitch while scrolling and sometimes contributed to overlap.
Disabling virtualization for the thread sizes users hit most often is the simplest and most reliable fix. It removes the unstable behavior directly while still keeping virtualization for larger threads.
UI Changes
This PR improves chat scroll stability and removes visible upward-scroll twitching in affected threads.
Checklist
  •  This PR is small and focused
  •  I explained what changed and why
  •  I included before/after screenshots for any UI changes
  •  I included a video for animation/interaction changes
Note
Improve timeline scroll stability with accurate row height estimation
  • Disables virtualization for short timelines (below MIN_ROWS_TO_ENABLE_VIRTUALIZATION) to avoid measurement overhead when it isn't needed.
  • Adds estimateTimelineWorkGroupHeight in timelineHeight.ts to size work-group rows based on visible entries, chip wrapping, and expansion state.
  • Adds estimateChangedFilesSummaryHeight and estimateTimelineRowHeight in MessagesTimeline.tsx to account for completion dividers and changed-files summaries in assistant message rows.
  • Adds countVisibleTurnDiffTreeNodes in turnDiffTree.ts to compute visible diff-tree node counts based on directory expansion state.
  • Behavioral Change: shouldAdjustScrollPositionOnItemSizeChange now triggers when remaining scroll distance is ≤ AUTO_SCROLL_BOTTOM_THRESHOLD_PX (previously only when greater), fixing auto-scroll near the bottom.
Macroscope summarized 0b7ecce.
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Feature/timeline scroll stabilityfix(web): reduce chat timeline scroll twitching and overlapMar 13, 2026
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i think the actual fix is to do better, more accurate, estimations and having regression tests (ChatView.browser.tsx) to verify estimate === actual ? I've fixed it couple times but when new UI changes are made and we don't update the estimates it regresses. Need tests to ensure it stays in sync.
@huxcruxhuxcrux
mentioned this pull request
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i think the actual fix is to do better, more accurate, estimations and having regression tests (ChatView.browser.tsx) to verify estimate === actual ? I've fixed it couple times but when new UI changes are made and we don't update the estimates it regresses. Need tests to ensure it stays in sync.
I created #1093 to fix the estimation, and is working on another PR implementing tests to avoid this from happening again in the future.
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Chat timeline content overlaps (assistant text + tool call cards stack on top of each other)


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@huxcrux@juliusmarminge

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
fix(web): reduce chat timeline scroll twitching and overlap - #1054
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huxcrux wants to merge 6 commits into
pingdotgg:mainfrom 
huxcrux:feature/timeline-scroll-stability
Closed
fix(web): reduce chat timeline scroll twitching and overlap#1054
huxcrux wants to merge 6 commits into
pingdotgg:mainfrom 
huxcrux:feature/timeline-scroll-stability
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commented
Mar 13, 2026•

edited by macroscopeapp
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What Changed
This PR reduces chat timeline scroll twitching and overlap.
Smaller and medium-sized threads now render without virtualization, which removes the late row mounting and remeasurement that were causing visible jumps while scrolling upward. Larger threads still use the standard virtualized path.
The remaining row height estimation is kept only for the cases that still need it:
grouped work/tool rows

assistant messages with changed-files summaries
Fixes#1035

Related to #988, #905, #860
Why
Older rows were being mounted and resized after entering view, which caused the timeline to twitch while scrolling and sometimes contributed to overlap.
Disabling virtualization for the thread sizes users hit most often is the simplest and most reliable fix. It removes the unstable behavior directly while still keeping virtualization for larger threads.
UI Changes
This PR improves chat scroll stability and removes visible upward-scroll twitching in affected threads.
Checklist
  •  This PR is small and focused
  •  I explained what changed and why
  •  I included before/after screenshots for any UI changes
  •  I included a video for animation/interaction changes
Note
Improve timeline scroll stability with accurate row height estimation
  • Disables virtualization for short timelines (below MIN_ROWS_TO_ENABLE_VIRTUALIZATION) to avoid measurement overhead when it isn't needed.
  • Adds estimateTimelineWorkGroupHeight in timelineHeight.ts to size work-group rows based on visible entries, chip wrapping, and expansion state.
  • Adds estimateChangedFilesSummaryHeight and estimateTimelineRowHeight in MessagesTimeline.tsx to account for completion dividers and changed-files summaries in assistant message rows.
  • Adds countVisibleTurnDiffTreeNodes in turnDiffTree.ts to compute visible diff-tree node counts based on directory expansion state.
  • Behavioral Change: shouldAdjustScrollPositionOnItemSizeChange now triggers when remaining scroll distance is ≤ AUTO_SCROLL_BOTTOM_THRESHOLD_PX (previously only when greater), fixing auto-scroll near the bottom.
Macroscope summarized 0b7ecce.
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Feature/timeline scroll stabilityfix(web): reduce chat timeline scroll twitching and overlapMar 13, 2026
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i think the actual fix is to do better, more accurate, estimations and having regression tests (ChatView.browser.tsx) to verify estimate === actual ? I've fixed it couple times but when new UI changes are made and we don't update the estimates it regresses. Need tests to ensure it stays in sync.
@huxcruxhuxcrux
mentioned this pull request
Mar 14, 2026
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i think the actual fix is to do better, more accurate, estimations and having regression tests (ChatView.browser.tsx) to verify estimate === actual ? I've fixed it couple times but when new UI changes are made and we don't update the estimates it regresses. Need tests to ensure it stays in sync.
I created #1093 to fix the estimation, and is working on another PR implementing tests to avoid this from happening again in the future.
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Chat timeline content overlaps (assistant text + tool call cards stack on top of each other)


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@huxcrux@juliusmarminge

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

Skip to content
fix(web): reduce chat timeline scroll twitching and overlap - #1054
Closed
huxcrux wants to merge 6 commits into
pingdotgg:mainfrom 
huxcrux:feature/timeline-scroll-stability
Closed
fix(web): reduce chat timeline scroll twitching and overlap#1054
huxcrux wants to merge 6 commits into
pingdotgg:mainfrom 
huxcrux:feature/timeline-scroll-stability
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@huxcrux
@huxcruxhuxcrux
commented
Mar 13, 2026•

edited by macroscopeapp
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What Changed
This PR reduces chat timeline scroll twitching and overlap.
Smaller and medium-sized threads now render without virtualization, which removes the late row mounting and remeasurement that were causing visible jumps while scrolling upward. Larger threads still use the standard virtualized path.
The remaining row height estimation is kept only for the cases that still need it:
grouped work/tool rows

assistant messages with changed-files summaries
Fixes#1035

Related to #988, #905, #860
Why
Older rows were being mounted and resized after entering view, which caused the timeline to twitch while scrolling and sometimes contributed to overlap.
Disabling virtualization for the thread sizes users hit most often is the simplest and most reliable fix. It removes the unstable behavior directly while still keeping virtualization for larger threads.
UI Changes
This PR improves chat scroll stability and removes visible upward-scroll twitching in affected threads.
Checklist
  •  This PR is small and focused
  •  I explained what changed and why
  •  I included before/after screenshots for any UI changes
  •  I included a video for animation/interaction changes
Note
Improve timeline scroll stability with accurate row height estimation
  • Disables virtualization for short timelines (below MIN_ROWS_TO_ENABLE_VIRTUALIZATION) to avoid measurement overhead when it isn't needed.
  • Adds estimateTimelineWorkGroupHeight in timelineHeight.ts to size work-group rows based on visible entries, chip wrapping, and expansion state.
  • Adds estimateChangedFilesSummaryHeight and estimateTimelineRowHeight in MessagesTimeline.tsx to account for completion dividers and changed-files summaries in assistant message rows.
  • Adds countVisibleTurnDiffTreeNodes in turnDiffTree.ts to compute visible diff-tree node counts based on directory expansion state.
  • Behavioral Change: shouldAdjustScrollPositionOnItemSizeChange now triggers when remaining scroll distance is ≤ AUTO_SCROLL_BOTTOM_THRESHOLD_PX (previously only when greater), fixing auto-scroll near the bottom.
Macroscope summarized 0b7ecce.
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Feature/timeline scroll stabilityfix(web): reduce chat timeline scroll twitching and overlapMar 13, 2026
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i think the actual fix is to do better, more accurate, estimations and having regression tests (ChatView.browser.tsx) to verify estimate === actual ? I've fixed it couple times but when new UI changes are made and we don't update the estimates it regresses. Need tests to ensure it stays in sync.
@huxcruxhuxcrux
mentioned this pull request
Mar 14, 2026
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i think the actual fix is to do better, more accurate, estimations and having regression tests (ChatView.browser.tsx) to verify estimate === actual ? I've fixed it couple times but when new UI changes are made and we don't update the estimates it regresses. Need tests to ensure it stays in sync.
I created #1093 to fix the estimation, and is working on another PR implementing tests to avoid this from happening again in the future.
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Chat timeline content overlaps (assistant text + tool call cards stack on top of each other)


2 participants

@huxcrux@juliusmarminge

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
fix(web): reduce chat timeline scroll twitching and overlap - #1054
Closed
huxcrux wants to merge 6 commits into
pingdotgg:mainfrom 
huxcrux:feature/timeline-scroll-stability
Closed
fix(web): reduce chat timeline scroll twitching and overlap#1054
huxcrux wants to merge 6 commits into
pingdotgg:mainfrom 
huxcrux:feature/timeline-scroll-stability
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@huxcrux
@huxcruxhuxcrux
commented
Mar 13, 2026•

edited by macroscopeapp
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What Changed
This PR reduces chat timeline scroll twitching and overlap.
Smaller and medium-sized threads now render without virtualization, which removes the late row mounting and remeasurement that were causing visible jumps while scrolling upward. Larger threads still use the standard virtualized path.
The remaining row height estimation is kept only for the cases that still need it:
grouped work/tool rows

assistant messages with changed-files summaries
Fixes#1035

Related to #988, #905, #860
Why
Older rows were being mounted and resized after entering view, which caused the timeline to twitch while scrolling and sometimes contributed to overlap.
Disabling virtualization for the thread sizes users hit most often is the simplest and most reliable fix. It removes the unstable behavior directly while still keeping virtualization for larger threads.
UI Changes
This PR improves chat scroll stability and removes visible upward-scroll twitching in affected threads.
Checklist
  •  This PR is small and focused
  •  I explained what changed and why
  •  I included before/after screenshots for any UI changes
  •  I included a video for animation/interaction changes
Note
Improve timeline scroll stability with accurate row height estimation
  • Disables virtualization for short timelines (below MIN_ROWS_TO_ENABLE_VIRTUALIZATION) to avoid measurement overhead when it isn't needed.
  • Adds estimateTimelineWorkGroupHeight in timelineHeight.ts to size work-group rows based on visible entries, chip wrapping, and expansion state.
  • Adds estimateChangedFilesSummaryHeight and estimateTimelineRowHeight in MessagesTimeline.tsx to account for completion dividers and changed-files summaries in assistant message rows.
  • Adds countVisibleTurnDiffTreeNodes in turnDiffTree.ts to compute visible diff-tree node counts based on directory expansion state.
  • Behavioral Change: shouldAdjustScrollPositionOnItemSizeChange now triggers when remaining scroll distance is ≤ AUTO_SCROLL_BOTTOM_THRESHOLD_PX (previously only when greater), fixing auto-scroll near the bottom.
Macroscope summarized 0b7ecce.
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Feature/timeline scroll stabilityfix(web): reduce chat timeline scroll twitching and overlapMar 13, 2026
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i think the actual fix is to do better, more accurate, estimations and having regression tests (ChatView.browser.tsx) to verify estimate === actual ? I've fixed it couple times but when new UI changes are made and we don't update the estimates it regresses. Need tests to ensure it stays in sync.
@huxcruxhuxcrux
mentioned this pull request
Mar 14, 2026
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closed this
Mar 14, 2026
@huxcrux
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ContributorAuthor
i think the actual fix is to do better, more accurate, estimations and having regression tests (ChatView.browser.tsx) to verify estimate === actual ? I've fixed it couple times but when new UI changes are made and we don't update the estimates it regresses. Need tests to ensure it stays in sync.
I created #1093 to fix the estimation, and is working on another PR implementing tests to avoid this from happening again in the future.
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Successfully merging this pull request may close these issues.

Chat timeline content overlaps (assistant text + tool call cards stack on top of each other)


2 participants

@huxcrux@juliusmarminge

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

Skip to content
fix(web): reduce chat timeline scroll twitching and overlap - #1054
Closed
huxcrux wants to merge 6 commits into
pingdotgg:mainfrom 
huxcrux:feature/timeline-scroll-stability
Closed
fix(web): reduce chat timeline scroll twitching and overlap#1054
huxcrux wants to merge 6 commits into
pingdotgg:mainfrom 
huxcrux:feature/timeline-scroll-stability
Conversation
@huxcrux
@huxcruxhuxcrux
commented
Mar 13, 2026•

edited by macroscopeapp
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What Changed
This PR reduces chat timeline scroll twitching and overlap.
Smaller and medium-sized threads now render without virtualization, which removes the late row mounting and remeasurement that were causing visible jumps while scrolling upward. Larger threads still use the standard virtualized path.
The remaining row height estimation is kept only for the cases that still need it:
grouped work/tool rows

assistant messages with changed-files summaries
Fixes#1035

Related to #988, #905, #860
Why
Older rows were being mounted and resized after entering view, which caused the timeline to twitch while scrolling and sometimes contributed to overlap.
Disabling virtualization for the thread sizes users hit most often is the simplest and most reliable fix. It removes the unstable behavior directly while still keeping virtualization for larger threads.
UI Changes
This PR improves chat scroll stability and removes visible upward-scroll twitching in affected threads.
Checklist
  •  This PR is small and focused
  •  I explained what changed and why
  •  I included before/after screenshots for any UI changes
  •  I included a video for animation/interaction changes
Note
Improve timeline scroll stability with accurate row height estimation
  • Disables virtualization for short timelines (below MIN_ROWS_TO_ENABLE_VIRTUALIZATION) to avoid measurement overhead when it isn't needed.
  • Adds estimateTimelineWorkGroupHeight in timelineHeight.ts to size work-group rows based on visible entries, chip wrapping, and expansion state.
  • Adds estimateChangedFilesSummaryHeight and estimateTimelineRowHeight in MessagesTimeline.tsx to account for completion dividers and changed-files summaries in assistant message rows.
  • Adds countVisibleTurnDiffTreeNodes in turnDiffTree.ts to compute visible diff-tree node counts based on directory expansion state.
  • Behavioral Change: shouldAdjustScrollPositionOnItemSizeChange now triggers when remaining scroll distance is ≤ AUTO_SCROLL_BOTTOM_THRESHOLD_PX (previously only when greater), fixing auto-scroll near the bottom.
Macroscope summarized 0b7ecce.
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Feature/timeline scroll stabilityfix(web): reduce chat timeline scroll twitching and overlapMar 13, 2026
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i think the actual fix is to do better, more accurate, estimations and having regression tests (ChatView.browser.tsx) to verify estimate === actual ? I've fixed it couple times but when new UI changes are made and we don't update the estimates it regresses. Need tests to ensure it stays in sync.
@huxcruxhuxcrux
mentioned this pull request
Mar 14, 2026
 Closed

4 tasks
@huxcruxhuxcrux
closed this
Mar 14, 2026
@huxcrux
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Mar 14, 2026

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ContributorAuthor
i think the actual fix is to do better, more accurate, estimations and having regression tests (ChatView.browser.tsx) to verify estimate === actual ? I've fixed it couple times but when new UI changes are made and we don't update the estimates it regresses. Need tests to ensure it stays in sync.
I created #1093 to fix the estimation, and is working on another PR implementing tests to avoid this from happening again in the future.
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Successfully merging this pull request may close these issues.

Chat timeline content overlaps (assistant text + tool call cards stack on top of each other)


2 participants

@huxcrux@juliusmarminge

, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

Skip to content
fix(web): reduce chat timeline scroll twitching and overlap - #1054
Closed
huxcrux wants to merge 6 commits into
pingdotgg:mainfrom 
huxcrux:feature/timeline-scroll-stability
Closed
fix(web): reduce chat timeline scroll twitching and overlap#1054
huxcrux wants to merge 6 commits into
pingdotgg:mainfrom 
huxcrux:feature/timeline-scroll-stability
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@huxcrux
@huxcruxhuxcrux
commented
Mar 13, 2026•

edited by macroscopeapp
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What Changed
This PR reduces chat timeline scroll twitching and overlap.
Smaller and medium-sized threads now render without virtualization, which removes the late row mounting and remeasurement that were causing visible jumps while scrolling upward. Larger threads still use the standard virtualized path.
The remaining row height estimation is kept only for the cases that still need it:
grouped work/tool rows

assistant messages with changed-files summaries
Fixes#1035

Related to #988, #905, #860
Why
Older rows were being mounted and resized after entering view, which caused the timeline to twitch while scrolling and sometimes contributed to overlap.
Disabling virtualization for the thread sizes users hit most often is the simplest and most reliable fix. It removes the unstable behavior directly while still keeping virtualization for larger threads.
UI Changes
This PR improves chat scroll stability and removes visible upward-scroll twitching in affected threads.
Checklist
  •  This PR is small and focused
  •  I explained what changed and why
  •  I included before/after screenshots for any UI changes
  •  I included a video for animation/interaction changes
Note
Improve timeline scroll stability with accurate row height estimation
  • Disables virtualization for short timelines (below MIN_ROWS_TO_ENABLE_VIRTUALIZATION) to avoid measurement overhead when it isn't needed.
  • Adds estimateTimelineWorkGroupHeight in timelineHeight.ts to size work-group rows based on visible entries, chip wrapping, and expansion state.
  • Adds estimateChangedFilesSummaryHeight and estimateTimelineRowHeight in MessagesTimeline.tsx to account for completion dividers and changed-files summaries in assistant message rows.
  • Adds countVisibleTurnDiffTreeNodes in turnDiffTree.ts to compute visible diff-tree node counts based on directory expansion state.
  • Behavioral Change: shouldAdjustScrollPositionOnItemSizeChange now triggers when remaining scroll distance is ≤ AUTO_SCROLL_BOTTOM_THRESHOLD_PX (previously only when greater), fixing auto-scroll near the bottom.
Macroscope summarized 0b7ecce.
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Review profile: CHILL
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Run ID: d90f1782-ff94-4231-b455-fced3f53d4b3
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Mar 13, 2026
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Feature/timeline scroll stabilityfix(web): reduce chat timeline scroll twitching and overlapMar 13, 2026
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i think the actual fix is to do better, more accurate, estimations and having regression tests (ChatView.browser.tsx) to verify estimate === actual ? I've fixed it couple times but when new UI changes are made and we don't update the estimates it regresses. Need tests to ensure it stays in sync.
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i think the actual fix is to do better, more accurate, estimations and having regression tests (ChatView.browser.tsx) to verify estimate === actual ? I've fixed it couple times but when new UI changes are made and we don't update the estimates it regresses. Need tests to ensure it stays in sync.
I created #1093 to fix the estimation, and is working on another PR implementing tests to avoid this from happening again in the future.
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Chat timeline content overlaps (assistant text + tool call cards stack on top of each other)


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