---
id: PLN-0013
ticket: studio-code-editor-workspace-foundations
title: Implement the read-only Code Editor workspace shell and passive surfaces
status: done
created: 2026-03-30
completed: 2026-03-30
tags:
  - studio
  - editor
  - implementation
  - layout
  - ui
---

## Objective

Replace the current hardcoded `EditorWorkspace` with the DEC-0008 read-only workspace shell: left navigator column with reserved `Outline` region, central tab/editor area, passive helper region, and passive status bar.

## Background

The current `EditorWorkspace` is only a `CodeArea` mounted under a toolbar.
DEC-0008 requires a stable read-only composition that reserves future surfaces without implementing semantic or writable behavior yet.

## Scope

### Included
- Recompose `EditorWorkspace` into the DEC-0008 structural layout.
- Introduce passive placeholder surfaces for `Outline`, helper, and status bar.
- Replace write-oriented/editorially misleading controls with a first-wave read-only shell.
- Keep the central editor body ready to host read-only opened file content.

### Excluded
- Project-tree scanning and refresh logic.
- Actual file opening/session state orchestration beyond the minimum shell integration points.
- Save, dirty tracking, write controls, or semantic/LSP behavior.

## Execution Steps

### Step 1 - Replace the current EditorWorkspace composition root

**What:**
Turn `EditorWorkspace` into a composition root that mounts the DEC-0008 layout instead of a single hardcoded `CodeArea`.

**How:**
Refactor the current border-pane structure into explicit regions:
1. left column for navigator + reserved outline region,
2. central work area for tab strip + read-only editor body,
3. bottom helper placeholder,
4. bottom status bar.
Prefer dedicated controls/panels over one large monolithic workspace class.

**File(s):**
- `prometeu-studio/src/main/java/p/studio/workspaces/editor/EditorWorkspace.java`
- `prometeu-studio/src/main/java/p/studio/workspaces/editor/`

### Step 2 - Introduce passive placeholder controls

**What:**
Add concrete passive UI surfaces for the reserved regions required by DEC-0008.

**How:**
Create lightweight controls/panels for:
1. reserved `Outline` region,
2. passive helper region,
3. passive status bar,
4. and the tab-strip shell.
These controls should be visually real, but functionally passive where DEC-0008 says behavior is deferred.

**File(s):**
- `prometeu-studio/src/main/java/p/studio/workspaces/editor/`

### Step 3 - Align editor chrome with read-only first-wave scope

**What:**
Remove or neutralize UI affordances that imply writable/editor-semantic behavior not present in this wave.

**How:**
Review the current toolbar and shell-level controls so the first-wave editor does not imply:
1. save,
2. run/build from inside the editor,
3. active outline,
4. or helper-driven functionality that does not exist yet.
If a control must remain for layout reasons, make it visually passive and consistent with DEC-0008.

**File(s):**
- `prometeu-studio/src/main/java/p/studio/workspaces/editor/EditorToolbar.java`
- `prometeu-studio/src/main/java/p/studio/workspaces/editor/`

## Test Requirements

### Unit Tests

- Add focused tests for any pure layout/session-state model extracted from the workspace shell composition.
- If dedicated status/tab placeholder models are introduced, cover their default state with unit tests.

### Integration Tests

- No JavaFX full integration harness is required as a prerequisite for this plan.

### Manual Verification

- Verify the workspace visually matches DEC-0008 layout.
- Verify the left column contains navigator + reserved outline region.
- Verify the helper and status bar are present but passive.
- Verify no visible control implies save/write behavior in the first wave.

## Acceptance Criteria

- [ ] `EditorWorkspace` is no longer a single hardcoded `CodeArea` view.
- [ ] The workspace visibly contains navigator, reserved outline region, central tab/editor area, helper placeholder, and status bar.
- [ ] The first-wave shell is visually coherent with DEC-0008 read-only scope.
- [ ] Placeholder surfaces are present without implying semantic or writable functionality.

## Dependencies

- DEC-0008 accepted.
- PLN-0012 should land first or in parallel if the wording is stable.

## Risks

- If the composition stays monolithic, later navigator/session work will be harder to integrate cleanly.
- Leaving write-oriented controls visible would immediately contradict DEC-0008 and confuse later implementation waves.