Unverified60% confidenceFactExact time
Google Docs maintains a hidden ARIA text layer outside the Canvas layer to address accessibility issues.
2
Sources
60%
Confidence
Long-term
Relevance
8/27/2026
First Seen
Sources
Related Entities
Related Claims
UnverifiedBecause Canvas content is an opaque bitmap to screen readers, editors must maintain a parallel ARIA tree or hidden DOM structure to convey document content and structure to assistive technologies.77% similarUnverifiedApps generated by Canvas run in the browser with no backend, and data is not persisted after the tab is closed.68% similarUnverified各平台 Accessibility API 实现差异大，部分应用（自定义渲染引擎的游戏、Electron 应用某些组件、Canvas 绑定的 Web 应用）可能不暴露完整文本信息，导致抓取覆盖率不稳定66% similarUnverified使用 Canvas、GPU 直接渲染或自绘 UI 的应用，其屏幕内容无法通过 Accessibility API 或 DOM 解析获取，只能退回到截图加 OCR 路径，这是纯文本屏幕记忆方案最根本的覆盖盲区66% similarUnverifiedThe combined architecture of a "PDF rendering layer + Canvas drawing layer" is the mainstream implementation approach for browser-based PDF handwriting tools.65% similar
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