yaze/docs/internal/architecture/layout-designer.md

Layout Designer (December 2025)

Canonical reference for the ImGui layout designer utility that lives in src/lab/layout_designer/. Use this in place of the older phase-by-phase notes and mockups.

Current Capabilities

• Two modes: Panel Layout (dock graph editing) and Widget Design (panel internals) toggled in the toolbar of LayoutDesignerWindow.
• Panel layout mode: Palette from PanelManager descriptors with search/category filter, drag-and-drop into a dock tree with split drop-zones, selection + property editing, zoom controls, optional code preview, and a theme panel. JSON export writes via LayoutSerializer::SaveToFile; import/export dialogs are stubbed.
• Widget design mode: Palette from yaze_widgets, canvas + properties UI, and code generation through WidgetCodeGenerator (deletion/undo/redo are still TODOs).
• Runtime import: ImportFromRuntime() builds a flat layout from the registered PanelDescriptors (no live dock positions yet). PreviewLayout() can apply DockBuilder ops against MainDockSpace when LayoutManager + PanelManager are wired, but it does not persist layouts.

Integration Quick Start

• Lab target: Build with -DYAZE_BUILD_LAB=ON and run the lab executable. The lab host opens the designer by default and provides the MainDockSpace dockspace for preview/testing.
• Embedding: If you want to host the designer elsewhere, wire it with a PanelManager + LayoutManager and draw it each frame.

#include "lab/layout_designer/layout_designer_window.h"

layout_designer::LayoutDesignerWindow layout_designer;
layout_designer.Initialize(&panel_manager, &layout_manager, nullptr);
layout_designer.Open();

if (layout_designer.IsOpen()) {
  layout_designer.Draw();
}

Improvement Backlog (code-aligned)

1. Preview/apply pipeline: Extend LayoutDesignerWindow::PreviewLayout() to cover full LayoutManager integration (persisted layouts + session-aware visibility) and avoid relying solely on MainDockSpace.
2. Serialization round-trip: Finish LayoutSerializer::FromJson() and wire real open/save dialogs. Validate versions/author fields and surface parse errors in the UI. Add a simple JSON schema example to layout_designer/README.md once load works.
3. Runtime import fidelity: Replace the flat import in ImportFromRuntime() with actual dock sampling (dock nodes, split ratios, and current visible panels), filtering out dashboard/welcome. Capture panel visibility per session instead of assuming all-visible defaults.
4. Editing polish: Implement delete/undo/redo for panels/widgets, and make widget deletion/selection consistent across both modes. Reduce debug logging spam (DragDrop noise) once the drop pipeline is stable.
5. Export path: Hook ExportCode() to write the generated code preview to disk and optionally emit a LayoutManager preset stub for quick integration.