Update RDS gui creation to new backend agnostic API

agents.md

@@ -0,0 +1,183 @@
+# MOLA Repository — AI Agent Context Guide
+
+## Project Overview
+
+**MOLA** (Modular Optimization framework for Localization and mApping) is a modern C++ and ROS 2 framework for robot **localization and SLAM** (Simultaneous Localization and Mapping). Key capabilities:
+- LiDAR Odometry (LO) and LiDAR-Inertial Odometry (LIO)
+- Configurable ICP and SLAM pipelines
+- Plug-and-play modules for custom localization systems
+- Geo-referenced map manipulation and sensor fusion
+- Standalone C++ or ROS 2 integration
+
+**Maintainer**: Jose Luis Blanco-Claraco
+**License**: GPL-3.0 (core) and BSD-3-Clause (utilities, bridge, demos)
+**Current Version**: 2.6.0
+**Official Docs**: https://docs.mola-slam.org/latest/
+
+---
+
+## Architecture
+
+MOLA uses a **plugin-based modular architecture**:
+
+1. All components implement virtual base interfaces defined in `mola_kernel`
+2. Modules are dynamically loaded by `mola_launcher` from YAML configuration files
+3. Data flows: `RawDataSource → Frontend → Filters → Map/Localization backends`
+4. Visualization is decoupled (backend-agnostic `VizInterface`)
+5. Runtime composition without recompilation via YAML configs
+
+---
+
+## Directory Structure
+
+```
+mola/                          # Metapackage (version tags, top-level docs)
+mola_kernel/                   # Core virtual interfaces and data types
+mola_yaml/                     # YAML parsing library with variable expansion
+mola_msgs/                     # ROS 2 message/service/action definitions
+mola_common/                   # External shared utilities (CMake macros)
+
+# Core Libraries
+mola_metric_maps/              # Advanced metric map classes (NDT, voxels, occupancy)
+mola_relocalization/           # Global localization and loop closure
+mola_pose_list/                # Searchable/spatial pose list data structure
+mola_viz/                      # GUI visualization system (backend-agnostic)
+
+# Data Input Sources (RawDataSource implementations)
+mola_input_rosbag2/            # ROS 2 bag file player
+mola_input_kitti_dataset/      # KITTI odometry/SLAM dataset reader
+mola_input_kitti360_dataset/   # KITTI-360 panoramic dataset reader
+mola_input_euroc_dataset/      # EuRoC UAV stereo dataset reader
+mola_input_video/              # Live/offline video sources (OpenCV)
+mola_input_rawlog/             # MRPT rawlog binary format
+mola_input_lidar_bin_dataset/  # Generic binary LiDAR format
+mola_input_mulran_dataset/     # MulRan urban SLAM dataset
+mola_input_paris_luco_dataset/ # Paris-LUCO dataset
+
+# Integration & Tooling
+mola_launcher/                 # CLI app (`mola-cli`) for launching MOLA systems
+mola_bridge_ros2/              # Bidirectional ROS 2 ↔ MOLA bridge
+mola_traj_tools/               # CLI tools for trajectory file manipulation
+mola_demos/                    # Example YAML launch configurations
+
+# Evaluation
+kitti_metrics_eval/            # KITTI benchmark evaluation tools
+```
+
+---
+
+## Key Packages In Depth
+
+### `mola_kernel` — Core Interfaces
+Location: `mola_kernel/include/mola_kernel/interfaces/`
+
+All plugin modules derive from these virtual base classes:
+- `ExecutableBase` — base for all executable modules
+- `RawDataSourceBase` — sensor/dataset data sources
+- `FrontEndBase` — LiDAR/visual frontend algorithms
+- `FilterBase` — generic filters
+- `NavStateFilter` — navigation state estimators
+- `LocalizationSourceBase` — localization systems
+- `MapSourceBase` / `MapServer` — map sources/servers
+- `VizInterface` — visualization (backend-agnostic, updated in v2.6)
+- `Relocalization` — global localization / loop closure
+- `OfflineDatasetSource` — offline dataset handling
+
+Other key types:
+- `GuiWidgetDescription` — descriptor for GUI widget creation (backend-agnostic)
+- `MinimalModuleContainer` — module loading and lifecycle
+
+### `mola_yaml` — YAML Parser
+Features: variable substitution (`$var`), file includes (`@include`), C++17 filesystem.
+Tests: `mola_yaml/tests/test-yaml-parser.cpp`
+
+### `mola_launcher` — CLI Entry Point
+- **`mola-cli`**: main executable, takes YAML config, loads and orchestrates modules
+- **`mola-yaml-parser`**: standalone tool for testing YAML parsing/variable expansion
+- **`mola-dir`**: directory and environment utilities
+
+### `mola_bridge_ros2` — ROS 2 Integration
+- Consumes ROS 2 sensor topics as MOLA `RawDataSource`
+- Publishes MOLA outputs (maps, poses) as ROS 2 topics/TF
+- Must have ROS 2 environment sourced before building
+
+### `mola_metric_maps` — Map Types
+- `OccupancyGridMap` (super-resolution)
+- `SparseVoxelPointCloud`
+- `NDTMap` (Normal Distribution Transform)
+- `KeyframeMap`
+- All support MRPT serialization
+
+---
+
+## Build System
+
+- **Build tool**: CMake 3.5+ / Colcon (for ROS 2)
+- **C++ standard**: C++17
+- **Config**: `colcon_defaults.yaml` (symlink install, RelWithDebInfo, compile_commands.json)
+- **CMake macros** (from `mola_common`): `mola_add_library()`, `find_mola_package()`
+- **Platforms**: Linux Ubuntu 22.04/24.04, AMD64 and ARM64
+
+Build standalone:
+```bash
+cmake -B build -DCMAKE_BUILD_TYPE=RelWithDebInfo
+cmake --build build
+```
+
+Build with ROS 2 (source workspace first):
+```bash
+colcon build --symlink-install
+```
+
+---
+
+## Key External Dependencies
+
+| Dependency | Purpose |
+|------------|---------|
+| **MRPT** (≥2.1.0) | Core robotics toolkit: poses, observations, maps, OpenGL GUI, serialization |
+| **mp2p_icp** | Point cloud ICP registration (used by relocalization and metric maps) |
+| **TBB** | Intel Threading Building Blocks for parallelism |
+| **OpenCV** | Image/video handling (via MRPT) |
+| **rclcpp** | ROS 2 C++ client library (optional, only if ROS 2 present) |
+| **rosbag2_cpp** | ROS 2 bag I/O (mola_input_rosbag2) |
+| **tf2** | ROS 2 transforms (mola_bridge_ros2) |
+
+---
+
+## Testing
+
+- **Framework**: CMake + GTest
+- Each package has `tests/` with its own `CMakeLists.txt`
+- CI/CD: `.github/workflows/` — builds on ROS 2 Humble, Jazzy, Kilted, Rolling
+- Style: enforced with `.clang-format` and `.clang-tidy`
+
+Test coverage exists for: `mola_yaml`, `mola_metric_maps`, `mola_pose_list`, `mola_relocalization`
+
+---
+
+## Common Patterns
+
+### Adding a New Module
+1. Inherit from appropriate `mola_kernel` interface (e.g., `RawDataSourceBase`)
+2. Override virtual methods (`initialize()`, `spinOnce()`, etc.)
+3. Register with `mola_launcher` plugin system via CMake macros
+4. Write YAML config for the module
+
+### YAML Configuration
+All MOLA systems are described in YAML. See `mola_demos/` for examples.
+Variable expansion and file includes are supported by `mola_yaml`.
+
+### GUI Widget Creation (v2.6+)
+Use `GuiWidgetDescription` for backend-agnostic widget creation in `VizInterface`.
+Do not use direct MRPT GUI calls in modules — use the `VizInterface` abstraction.
+
+---
+
+## File Navigation Tips
+
+- Interface definitions: `mola_kernel/include/mola_kernel/interfaces/`
+- GUI/widget types: `mola_kernel/include/mola_kernel/` (look for `GuiWidgetDescription`)
+- Example configs: `mola_demos/mola-cli-launchs/`
+- Per-package docs: each directory has a `README.md`
+- Main docs source: `docs/` (Sphinx + Doxygen)

mola_kernel/src/interfaces/RawDataSourceBase.cpp

@@ -17,6 +17,7 @@
  * @date   Nov 21, 2018
  */
 
+#include <mola_kernel/GuiWidgetDescription.h>
 #include <mola_kernel/interfaces/RawDataSourceBase.h>
 #include <mola_kernel/interfaces/VizInterface.h>
 #include <mola_yaml/yaml_helpers.h>
@@ -39,7 +40,7 @@ struct RawDataSourceBase::SensorViewerImpl
   std::string            win_pos;  //!< "[x,y,width,height]"
   mrpt::containers::yaml extra_parameters;
 
-  nanogui::Window* win = nullptr;
+  bool gui_created = false;
 };
 
 RawDataSourceBase::RawDataSourceBase() = default;
@@ -200,28 +201,27 @@ void RawDataSourceBase::sendObservationsToFrontEnds(const mrpt::obs::CObservatio
         auto viz = std::dynamic_pointer_cast<VizInterface>(vizMods.at(0));
 
         // Create GUI upon first call:
-        if (!sv->win)
+        if (!sv->gui_created)
         {
-          // get std::future and wait for it:
-          auto fut = viz->create_subwindow(sv->sensor_label);
-          sv->win  = fut.get();
+          mola::gui::WindowDescription desc;
+          desc.title = sv->sensor_label;
 
-          auto futLayout =
-              viz->subwindow_grid_layout(sv->sensor_label, true /*vertical?*/, 1 /*col count*/);
-          futLayout.get();
-
-          // Replace and resize, if user provided "win_pos":
-          if (sv->win && !sv->win_pos.empty())
+          // Apply user-provided position/size if available:
+          if (!sv->win_pos.empty())
           {
             int                x = 0, y = 0, w = 400, h = 300;
             std::istringstream ss(sv->win_pos);
-            // parse: "x y w h"
             if ((ss >> x) && (ss >> y) && (ss >> w) && (ss >> h))
             {
-              auto futMove = viz->subwindow_move_resize(sv->sensor_label, {x, y}, {w, h});
-              (void)futMove;
+              desc.position = {x, y};
+              desc.size     = {w, h};
             }
           }
+
+          auto fut = viz->create_subwindow_from_description(desc);
+          fut.get();
+
+          sv->gui_created = true;
         }
 
         // Update the GUI:

mola_viz/src/MolaViz.cpp

@@ -1441,8 +1441,13 @@ std::future<void> MolaViz::create_subwindow_from_description(
 
         if (desc.tabs.empty())
         {
-          // Legacy bare subwindow: no layout or size constraints set.
-          // Callers populate the window and manage layout themselves.
+          // Bare subwindow (no widget description).  Set a default vertical
+          // single-column GridLayout so that children added directly to the
+          // window (e.g. MRPT2NanoguiGLCanvas added by gui handlers) are
+          // positioned inside the subwindow frame rather than floating.
+          // This matches the old subwindow_grid_layout(title, true, 1) call.
+          subwin->setLayout(new nanogui::GridLayout(
+              nanogui::Orientation::Vertical, 1, nanogui::Alignment::Fill, 2, 2));
         }
         else
         {