Rendered Edit Session
May 22, 2026 · View on GitHub
Foundation types for the Rendered Edit Session PRD. Start with the architecture overview for motivation, commit policy, regression matrix, and design decisions. Block-type wiring is documented in linked pages below.
Module: src/markdown/rendered_session.rs
Types
| Type | Purpose |
|---|---|
BlockRef | Stable block identity (line + kind); widget_id for egui TextEdit ids |
BlockEditState | Per-block buffer, dirty flag, formatted edit mode, pending activation |
PendingActivation | One-shot cursor/focus request for next frame |
CommitPolicy | SaveIfDirty or Discard on close |
RenderedEditSession | At most one active block; HashMap of buffers |
Session API
| Method | Behavior |
|---|---|
switch_to | Close previous (SaveIfDirty), set active, queue activation |
switch_to_ui | Same + surrender previous block's egui focus |
close_active / close_active_ui | Clear active; commit or discard per policy |
on_text_changed | Update buffer, mark dirty (no source write) |
commit_active | Force-commit active buffer via callback |
discard_active | Reload buffer from source via callback |
invalidate_buffers | Clear all state after source_epoch bump |
load_for_epoch / save_for_epoch | Load/save with epoch tracking; auto-invalidate on mismatch |
open_formatted_display | Set formatted_editing = false for a block |
Commit callbacks receive (BlockRef, &BlockEditState) so callers write to tab source without the session owning Tab. Undo is recorded at commit boundaries via rendered_commit_undo (not per in-session keystroke).
egui storage
Tab-scoped temp memory keyed by editor id (not global):
let session = rendered_session::load(ui, editor_id);
// ... mutate ...
rendered_session::save(ui, editor_id, session);
Storage id: editor_id.with("rendered_edit_session").
Widget ids
BlockRef::widget_id(ui) uses stable key paths under the rendered editor scope (e.g. heading_text, para_text, list_item_text, table/cell). Do not invent new suffixes when wiring render paths.
Block wiring status
| Block type | Session-backed | Doc |
|---|---|---|
| Headings | Yes | Headings |
| Plain paragraphs | Yes | Paragraphs & lists |
| Simple list items | Yes | Paragraphs & lists |
| Formatted blocks | Yes | Formatted |
| Tables | Yes (BlockRef::TableCell + force-commit signal) | Tables |
Widget identity: show_rendered_editor uses ui.push_id(editor_id) + ui.push_id(source_epoch). See rendered-widget-identity.md.
Related
- Architecture overview — hub doc, RS-1…RS-7, open questions
- Split view parity — shared
rendered_editor_id+ epoch invalidation (RS-6) - Headings — first session-wired block type
- Phase 0 — formatted blur hotfix +
source_epoch - PRD — full architecture
Tests
cargo test rendered_session:: — switch/commit/discard invariants, widget_id suffix stability, storage roundtrip.