Add VS Code Dev Container Configuration

.devcontainer/Dockerfile

@@ -0,0 +1,76 @@
+# Use Ubuntu 24.04 LTS as base image
+FROM ubuntu:24.04
+
+# Avoid prompts from apt
+ENV DEBIAN_FRONTEND=noninteractive
+
+# Set up locale
+RUN apt-get update && apt-get install -y locales && \
+    locale-gen en_US.UTF-8 && \
+    update-locale LANG=en_US.UTF-8
+
+ENV LANG=en_US.UTF-8
+ENV LANGUAGE=en_US:en
+ENV LC_ALL=en_US.UTF-8
+
+# Install build dependencies
+RUN apt-get update && apt-get install -y \
+    # Build tools
+    build-essential \
+    cmake \
+    git \
+    ninja-build \
+    pkg-config \
+    intltool \
+    gettext \
+    po4a \
+    xsltproc \
+    libxml2-utils \
+    python3-jsonschema \
+    # Required dependencies
+    libgtk-3-dev \
+    libglib2.0-dev \
+    libsqlite3-dev \
+    libcurl4-openssl-dev \
+    libpng-dev \
+    libexiv2-dev \
+    libpugixml-dev \
+    liblensfun-dev \
+    libjpeg-dev \
+    libtiff-dev \
+    liblcms2-dev \
+    librsvg2-dev \
+    libjson-glib-dev \
+    # Optional dependencies for full functionality
+    libomp-dev \
+    llvm-dev \
+    ocl-icd-opencl-dev \
+    liblua5.4-dev \
+    libgphoto2-dev \
+    libimath-dev \
+    libavif-dev \
+    libheif-dev \
+    libjxl-dev \
+    libwebp-dev \
+    libcolord-dev \
+    libportmidi-dev \
+    libsdl2-dev \
+    libcups2-dev \
+    libopenexr-dev \
+    libopenjp2-7-dev \
+    libgraphicsmagick1-dev \
+    # Additional tools
+    clang-format \
+    vim \
+    nano \
+    wget \
+    curl \
+    sudo \
+    # AppImage building tools
+    desktop-file-utils \
+    && rm -rf /var/lib/apt/lists/*
+
+# Set the working directory
+WORKDIR /workspace
+
+CMD ["/bin/bash"]

.devcontainer/README.md

@@ -0,0 +1,169 @@
+# Darktable Development Container
+
+A complete development environment for building and testing darktable with all dependencies pre-installed.
+
+## Purpose
+
+This devcontainer provides:
+- ✅ Build darktable from source
+- ✅ Create AppImage for GUI testing on host
+- ✅ Debug with GDB
+- ❌ Does NOT run GUI inside container (use AppImage on host)
+
+## Prerequisites
+
+- [Docker](https://www.docker.com/products/docker-desktop/)
+- [Visual Studio Code](https://code.visualstudio.com/) with [Dev Containers extension](https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers)
+
+## Quick Start
+
+1. Open this repository in VS Code
+2. Click "Reopen in Container" when prompted (or F1 → "Dev Containers: Reopen in Container")
+3. Wait for container build (~5-10 minutes first time)
+4. Git submodules are initialized automatically
+5. You're ready to build!
+
+## Building Darktable
+
+### Basic Build (for development)
+
+```bash
+# Build darktable (binaries in ./build/bin/)
+./build.sh --prefix /tmp/dt --build-type RelWithDebInfo
+
+# Run from build directory
+./build/bin/darktable --version
+```
+
+### Build with Debug Symbols
+
+```bash
+./build.sh --prefix /tmp/dt --build-type Debug
+```
+
+### Clean Build
+
+```bash
+rm -rf build
+./build.sh --prefix /tmp/dt --build-type RelWithDebInfo
+```
+
+## Testing
+
+### GUI Testing with AppImage
+
+GUI testing requires building an AppImage and running it on your host system:
+
+```bash
+# 1. Create lensfun directory (avoids warnings)
+sudo mkdir -p /var/lib/lensfun-updates
+
+# 2. Build AppImage (takes ~10-15 minutes)
+APPIMAGE_EXTRACT_AND_RUN=1 ./tools/appimage-build-script.sh
+
+# 3. The AppImage is created in: build/Darktable-*.AppImage
+```
+
+**To run on your host:**
+
+```bash
+# From host terminal (not in container)
+# If workspace is mounted, the AppImage is accessible at:
+cd <repo-path>/build
+
+# Make executable and run
+chmod +x Darktable-*.AppImage
+./Darktable-*.AppImage --configdir ~/.config/darktable-test
+```
+
+**Using `--configdir`** creates a separate configuration to avoid conflicts with your production darktable installation.
+
+## Development Tools Included
+
+- **Compilers:** GCC 13, Clang
+- **Build Systems:** CMake, Ninja, Make
+- **Libraries:** GTK3, GLib, SQLite, libcurl, Exiv2, libavif, libheif, libjxl, WebP, and more
+- **VS Code Extensions:** C/C++ tools, CMake Tools, clang-format
+- **Editors:** vim, nano
+
+## Troubleshooting
+
+### Build fails with missing dependencies
+
+```bash
+# Rebuild the container
+# F1 → "Dev Containers: Rebuild Container"
+```
+
+### Git submodules not initialized
+
+```bash
+git submodule init && git submodule update
+```
+
+### AppImage build fails with FUSE error
+
+Always use the environment variable:
+```bash
+APPIMAGE_EXTRACT_AND_RUN=1 ./tools/appimage-build-script.sh
+```
+
+### Need to install additional packages
+
+```bash
+sudo apt-get update
+sudo apt-get install <package-name>
+```
+
+### Want to enable unit tests?
+
+Tests are disabled by default and require additional dependencies. To enable:
+
+```bash
+# Install test framework
+sudo apt-get install -y libcmocka-dev
+
+# Build with tests enabled
+./build.sh --prefix /tmp/dt --build-type RelWithDebInfo -- -DBUILD_TESTING=ON
+
+# Run tests
+cd build && ctest
+```
+
+## File Structure
+
+```
+.devcontainer/
+├── devcontainer.json    # Container configuration
+├── Dockerfile           # Environment setup with all build dependencies
+└── README.md           # This file
+```
+
+## Build Options Reference
+
+```bash
+# Build types
+--build-type Release          # Optimized, no debug info
+--build-type Debug            # Debug symbols, no optimization
+--build-type RelWithDebInfo   # Optimized + debug symbols (recommended)
+
+# Parallel jobs
+-j N                          # Use N parallel jobs (default: all CPUs)
+
+# Installation
+--prefix <path>               # Set installation prefix (not required for development)
+--install                     # Actually install files (not recommended in container)
+```
+
+## Notes
+
+- Workspace folder mounted at `/workspaces/darktable`
+- Build artifacts go to `build/` directory
+- Container runs as user `vscode` (UID 1000)
+- Git submodules initialized automatically on container creation
+
+## Resources
+
+- [Darktable Build Instructions](https://github.com/darktable-org/darktable#building)
+- [Developer's Guide](https://github.com/darktable-org/darktable/wiki/Developer's-guide)
+- [User Manual](https://docs.darktable.org/)

.devcontainer/devcontainer.json

@@ -0,0 +1,33 @@
+{
+  "name": "Darktable Development",
+  "build": {
+    "dockerfile": "Dockerfile",
+    "context": ".."
+  },
+  "runArgs": [
+    "--cap-add=SYS_PTRACE",
+    "--security-opt=seccomp=unconfined"
+  ],
+    "features": {
+    "ghcr.io/devcontainers/features/common-utils:2": {
+      "username": "vscode"
+    }
+  },
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "ms-vscode.cpptools",
+        "ms-vscode.cmake-tools",
+        "xaver.clang-format",
+        "ms-vscode.cpptools-extension-pack"
+      ],
+      "settings": {
+        "cmake.configureOnOpen": false,
+        "C_Cpp.default.configurationProvider": "ms-vscode.cmake-tools"
+      }
+    }
+  },
+  "forwardPorts": [],
+  "postCreateCommand": "git submodule init && git submodule update && echo 'Development environment ready! See .devcontainer/README.md for build instructions.'",
+  "remoteUser": "vscode"
+}

.gitignore

@@ -27,3 +27,4 @@ CMakeLists.txt.user
 workspace/
 cmake-build-debug/
 .idea/
+AppDir/