From 0764ee24e00ccfd24d6c4669af391a6d8693e5fd Mon Sep 17 00:00:00 2001
From: hechang27-sprt <hechang27@outlook.com>
Date: Wed, 1 Apr 2026 16:24:41 +0800
Subject: [PATCH] chore(task): archive 04-01-pretext-integration

---
 .../2026-04/04-01-pretext-integration/prd.md  | 83 +++++++++++++++++++
 .../04-01-pretext-integration/task.json       | 44 ++++++++++
 2 files changed, 127 insertions(+)
 create mode 100644 .trellis/tasks/archive/2026-04/04-01-pretext-integration/prd.md
 create mode 100644 .trellis/tasks/archive/2026-04/04-01-pretext-integration/task.json

diff --git a/.trellis/tasks/archive/2026-04/04-01-pretext-integration/prd.md b/.trellis/tasks/archive/2026-04/04-01-pretext-integration/prd.md
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+# Pretext.js Integration for list-table-v2
+
+## Goal
+
+Replace the mini-table DOM measurement approach with Pretext.js for calculating text heights in list-table-v2, eliminating forced synchronous reflow and improving performance.
+
+## Context
+
+### Current State
+- list-table-v2 uses a hidden mini-table to measure row heights via `getBoundingClientRect()`
+- This triggers forced synchronous reflow (~94ms for 1000 items)
+- The mini-table approach works but has performance cost
+
+### Target State
+- Use Pretext.js to calculate text heights mathematically (no DOM access)
+- Keep mini-table for custom renderer columns (or use running max heuristic)
+- Reduce/eliminate reflow during height calculation
+
+## Requirements
+
+### Must Have
+1. [ ] Install `@chenglou/pretext` dependency
+2. [ ] Calculate column widths mathematically (flexbox replication)
+3. [ ] Integrate Pretext into `renderCellContent` for text-only columns
+4. [ ] Fallback for custom renderer columns (keep mini-table or use heuristic)
+5. [ ] Support horizontal resize (recalculate widths when container width changes)
+
+### Should Have
+6. [ ] Verify width calculation matches el-table-v2 actual rendering
+7. [ ] Performance benchmark comparing old vs new approach
+
+## Technical Approach
+
+### 1. Width Calculation
+- Use `useColumnWidthCalculator` (already created)
+- Formula: `width = flexBasis + (freeSpace * flexGrow / totalFlexGrow)`
+- Handle shrinking case: `width = flexBasis + (freeSpace * flexShrink / totalFlexShrink)`
+- Clamp to [minWidth, maxWidth]
+
+### 2. Pretext Integration
+```ts
+// In renderCellContent
+import { prepare, layout } from '@chenglou/pretext'
+
+// Prepare once per text/font pair
+const prepared = prepare(cellData, '14px Inter')
+
+// Layout at runtime with calculated width
+const { height } = layout(prepared, textMaxWidth, lineHeight)
+```
+
+### 3. Hybrid Approach for Custom Renderers
+- Text-only columns: Use Pretext directly
+- Custom renderer columns: Use running maximum heuristic
+  - Initial estimate based on worst-case content
+  - Update `estimatedRowHeight` with actual observed maximum on scroll
+
+## Files to Modify
+
+1. `packages/base/data/list-table-v2.vue`
+   - Add Pretext import
+   - Modify `renderCellContent` to use Pretext for text columns
+   - Handle custom renderer fallback
+
+2. `packages/base/data/useColumnWidthCalculator.ts`
+   - May need refactoring to work with Vue's script setup order
+
+## Risks & Mitigation
+
+| Risk | Mitigation |
+|------|------------|
+| Initialization order issue | Integrate Pretext directly, not via separate composable |
+| Width calculation mismatch | Benchmark against actual el-table-v2 widths |
+| Custom renderer fallback | Keep mini-table as fallback for non-text columns |
+
+## Acceptance Criteria
+
+1. [ ] Table renders without errors at http://localhost:5173/#/table-v2
+2. [ ] Horizontal scroll works in Combined Test (section 13)
+3. [ ] Fixed columns display correctly
+4. [ ] No "Cannot access 'tableColumns' before initialization" error
+5. [ ] Performance: Height calculation completes without triggering reflow
+6. [ ] Basic Usage (section 1) still works correctly
diff --git a/.trellis/tasks/archive/2026-04/04-01-pretext-integration/task.json b/.trellis/tasks/archive/2026-04/04-01-pretext-integration/task.json
new file mode 100644
index 0000000..f3345d1
--- /dev/null
+++ b/.trellis/tasks/archive/2026-04/04-01-pretext-integration/task.json
@@ -0,0 +1,44 @@
+{
+  "id": "pretext-integration",
+  "name": "pretext-integration",
+  "title": "Pretext.js Integration for list-table-v2",
+  "description": "",
+  "status": "completed",
+  "dev_type": null,
+  "scope": null,
+  "priority": "P2",
+  "creator": "hechang27-sprt",
+  "assignee": "hechang27-sprt",
+  "createdAt": "2026-04-01",
+  "completedAt": "2026-04-01",
+  "branch": null,
+  "base_branch": "dev",
+  "worktree_path": null,
+  "current_phase": 0,
+  "next_action": [
+    {
+      "phase": 1,
+      "action": "implement"
+    },
+    {
+      "phase": 2,
+      "action": "check"
+    },
+    {
+      "phase": 3,
+      "action": "finish"
+    },
+    {
+      "phase": 4,
+      "action": "create-pr"
+    }
+  ],
+  "commit": null,
+  "pr_url": null,
+  "subtasks": [],
+  "children": [],
+  "parent": null,
+  "relatedFiles": [],
+  "notes": "",
+  "meta": {}
+}
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