ARCADIA-Studio/harness/release-capella-basic-editing-20260907.md

Capella 7.1 basic editing benchmark and redesign

The user's rejection of the large horizontal creation buttons supersedes the previous toolbar proposal. On 2026-09-07 the user explicitly requested consulting the installed Capella through Computer Use. That renewed authorization follows the earlier Escape stop; native consultation resumed on a disposable project.

Environment and method

Actual executable: C:\Users\User\capella-7.1.0.202606231255-win32-win32-x86_64\capella\capella.exe. An isolated workspace .local/capella-basic-ux-20260907 contains the native-created project Basic Editing Benchmark. The [OAB] Operational Entities diagram was opened from the Operational Analysis workflow. Observations below were made in the real application at approximately 1010 × 760, using Computer Use. Saved .capella XML independently establishes the semantic result of creation and allocation. This is separate from the older Capella 7.0 benchmark.

Observed behavior

• A narrow right palette groups Entities, Roles, Activities, Accelerators and Common tools. It collapses completely. Its context menu offers List, Columns, Icons Only and Details, plus an independent large-icons option. Icons Only was exercised: small glyphs and tooltips expose the contextual tools without a horizontal creation row. Some labels in List mode clipped at this width.
• Selecting Operational Entity and clicking the canvas creates OE 1. F2 edits the label directly on the node; entering Rescue team and pressing Enter updates the model and Properties. Selection also changes a formatting toolbar and shifts Capella's canvas vertically; that jump is a weakness to avoid copying.
• Selecting Operational Activity and clicking inside Rescue team creates a nested activity and expands its graphical container. The saved activity remains under the root Operational Activity, with a separate ComponentFunctionalAllocation from the Entity. Graphical nesting therefore does not imply semantic ownership.
• Saved identities: Entity 3cb395ad-2932-402c-bd51-6a667a45940e, Activity 29a873f8-eb2a-41bd-b48f-3ef6a973027b, allocation 5693d9ff-9a45-4809-b090-edf4b0f01c0e. Only this disposable model was changed.
• The Manage Activity Allocation tooltip explicitly describes connecting an existing activity to a participant and displaying it there. The endpoint action itself was not exercised in this pass.
• Interactions and Operational Processes Insert/Remove tooltips explicitly distinguish changing graphical presence from deleting semantic objects. These tooltips were inspected; no insertion/removal operation is claimed as tested.
• The Entity context menu exposes Transitions and Allocation Management. Create System Actor opens a large candidate/result merge preview. Clicking OK closed it, but the saved model did not contain the proposed SA actor. This establishes contextual initiation and preview, not a successful transition. No automatic merge behavior is inferred from the dialog closing.

Alternatives and decision

The rejected horizontal buttons made common commands visible but consumed canvas height and changed its origin during placement. Context-menu-only creation would save space but hide the primary workflow. A permanently expanded catalogue would repeat the global-list problem. Select a compact side palette with explicit label expansion and contextual menus as a second entry point.

The implementation target is a neutral 36 px palette, explicitly expandable to 156 px. It contains projection-compatible creation and connection tools, compact vector icons, tooltips and clear selected-tool feedback. Only toggling its width may resize the canvas; arming a tool, typing, validation, committing and cancelling must not move the clicked location on screen.

Creation is tool → canvas point → name in place → Enter. Escape cancels without accepting a placeholder. F2 uses the same in-place editor for Rename. Add existing offers compatible unplaced objects by default, with explicit broader filtering and Locate for already placed objects. Contextual Add activity / Add function on a participant names that performer and creates the work plus allocation in one undoable transaction. Ordinary root creation remains unallocated. Connections belong in the same palette, not a second permanent button row.

This adopts Capella's useful interaction and domain distinctions while avoiding its clipped labels, immediate placeholder commits and large merge dialogue for ordinary creation. The proposed editor is still an implementation hypothesis; compactness alone does not establish usability.

Acceptance still required

Inspect the actual new executable at wide and minimum sizes. Check discovery, tool state, pointer placement, name focus, Enter/Escape, long names and edge clamping; canvas origin must remain stable through every drafting phase. Exercise F2, compatible existing-object insertion, explicit allocated work and connection creation. Verify exact source/model Save, Undo, Redo and recovery, followed by ordinary forward/reverse transition destination selection. Preserve the existing independent oracle; update its interaction instructions, not its expected model to match whatever the new UI happens to produce.

The prior v1 build passed 584 desktop tests and build/lint gates, but remains a rejected UI with an observed 22 px placement jump. Its pass does not transfer to this redesign. The release goal remains active and incomplete.