DBeaver Results Grid and Diagram Canvas Lack Accessible Roles

Direct Answer

Do not migrate to native toolkits as a first step. The optimal strategy is to keep DBeaver's custom Canvas rendering for performance and attach SWT AccessibleListener and AccessibleControlListener to each canvas, exposing a compact semantic model: a virtual table for the results grid and discrete accessible children for the ER diagram. A hybrid stack that overlays a transparent canvas on a native table is risky because it can hide or duplicate the accessible tree; choose one path—either native widgets with owner-draw, or a custom canvas with a complete accessible model.

Likely Explanation vs. Confirmed Facts

Likely: Custom-drawn SWT Canvas controls do not automatically provide table, row, column, or graphic roles to assistive technologies. Without explicit accessible metadata, screen readers receive only a generic canvas or unknown role.

Confirmed by SWT behavior: SWT supports accessible listeners on any control, including Canvas. You can publish getName(), getDescription(), getRole(), getState(), getValue(), and child IDs. Cross-platform mappings differ: Windows uses UI Automation/MSAA, macOS uses NSAccessibility, and Linux uses AT-SPI. Role and event support is uneven, so fallbacks via name, description, and value are safer than relying on a single role.

Unconfirmed: The premise that DBeaver currently uses raw Canvas for these components. Some builds may use virtual Table/Tree with owner-draw. Inspect the actual accessible tree before refactoring.

Steps for This Case

1. Verify the widget implementation. Run Windows Inspect.exe, macOS Accessibility Inspector, or Linux Accerciser against the same DBeaver build. Capture the class, role, name, and states for grid cells and diagram nodes. If the control is already a native table, adjust owner-draw accessible properties instead of adding canvas listeners.
2. Results grid: virtual table model. Expose row and column counts, column headers, the current cell name and value, and selection state. Do not create an accessible object per cell. Cache metadata, compute names lazily, and refresh accessibility only on focus, selection, or data changes.
3. ER diagram: logical child objects. Publish diagram entities as accessible children with stable IDs, names, roles, and states. Implement arrow-key and Tab traversal to move logical focus and update the announced object. Keep names concise; place extra detail in descriptions.
4. Benchmark. Measure scrolling and cell selection with a large result set before and after adding listeners to confirm no per-cell overhead.

One Missing Diagnostic

Provide the widget class and inspector output for your OS and screen reader. If the grid is a virtual SWT Table, the fix is to correct accessible properties on the existing native control; if it is a raw Canvas, the fix is to add a complete accessible model. That distinction changes the implementation path.