Hacktoberfest 2026：维护者为十月标记出来的 issue，仍然开放、适合新手。 浏览 Hacktoberfest issue

Add indentation guides to the code editor

未关闭
  • 哪里不对？
#254 2 条评论 0 个 reaction 已指派 1 人 在 GitHub 查看

维护者通常 1 天内回复

@sidney-Hung 已经在做这个了。

开始于 2026年10月7日。

  • #267 来自 @sidney-Hung —— 未关闭

评估

这个 Issue 还没有评估数据。

描述

Summary

Add vertical indentation guides (indent lines) to the code editor component to improve visual hierarchy and readability when navigating nested code.

Motivation / Problem Statement

When viewing or editing code with multiple levels of nesting it can be difficult to visually trace which indentation level matches which block.

Adding indentation guides will:

  • Make block scope and code hierarchy clear at a glance.
  • Prevent misaligned code during editing.
Proposed Architecture & Changes

The editor relies on multiple synchronized layers stacked behind the <textarea> (the line-number gutter, the syntax-color overlay, and the input textarea itself). This change introduces a dedicated fourth layer, #editor-guides, positioned beneath the syntax-color overlay:

File Proposed Change
web/indent-guides.js (new) Implements indentGuides(code) to generate HTML for the guides layer. Each full 4-column indent level produces a <span class="indent-guide">. Tabs and 4 spaces align to the same guide; partial indentation yields no guide.
web/interview.html Injects the <pre id="editor-guides"> layer into the editor markup.
web/interview.js Repaints guide lines strictly on text changes (paintEditor()), bypassing unnecessary redraws on caret movement. Synchronizes scroll offsets (scrollTop, scrollLeft) with the textarea.
web/styles.css Enforces font, sizing, padding, and tab-stop parity across layers. Sets guide text to transparent and disables pointer events (pointer-events: none). Renders guides as 1px grey vertical lines spanning the full line height.
Key Design Decisions & Considerations
  • Full-Line Layout Rendering: Rather than rendering only leading whitespace, the entire line is written out with transparent text. This ensures #editor-guides shares the exact scrollable scrollWidth and scrollHeight as <textarea>, preventing guide alignment drift on long lines or near file bottoms.
  • Blank-Line Depth Continuity: Empty lines inherit the shallower depth of their nearest non-blank neighbors (min(prev_indent, next_indent)). Guides run unbroken through blank lines inside a block and terminate cleanly once the block ends.
  • Continuous Vertical Lines: Uses display: inline-block instead of standard inline spans to ensure each segment reaches the full line height, rendering solid continuous lines instead of broken dashes.
  • Separation of Concerns: The existing syntax highlighter and <textarea> remain untouched. The trade-off is managing font, sizing, and scroll synchronization across one additional layer.
Verification & Testing
  • tests/browser/indent-guides.test.js (new): 7 tests covering nesting depth, tab vs. space mixing, HTML character escaping, blank-line width calculation, and trailing newlines.
  • tests/browser/editor-font-size.test.js: Extended to assert that the guide layer maintains identical alignment with the <textarea> across all font sizes.
Result
Image
主要语言
Rust
星标
144
派生
41
平均合并
1 天 7 小时
30 天内合并 PR
94

环境准备

  • 没有 Dockerfile 或 Docker Compose 文件
  • 没有 Pull Request 模板
  • 阅读贡献指南

从这里开始

  1. 先读完整个 Issue，再读项目的贡献指南。
  2. 在 Issue 下留言说明你要接手 —— 这能避免两个人做同样的事。
  3. Fork 仓库，在一个分支上完成修改。
  4. 提交 Pull Request，并在描述里引用这个 Issue 编号。

sysprog21/codetrial 的其他 Issue

查看 sysprog21/codetrial 的全部 Issue

相似的 Issue

更多 Rust Issue

把新 issue 发到你的邮箱

精选适合新手参与的 GitHub issue 摘要。