feat: add bec-app script to launch applications

bec_widgets/applications/alignment/alignment_1d/alignment_1d.py

@@ -249,7 +249,7 @@ class Alignment1D(BECWidget, QWidget):
         box.ui.position_indicator.setFixedHeight(20)
 
 
-if __name__ == "__main__":  # pragma: no cover
+def main():
     import sys
 
     from qtpy.QtWidgets import QApplication  # pylint: disable=ungrouped-imports
@@ -263,3 +263,7 @@ if __name__ == "__main__":  # pragma: no cover
     window = Alignment1D()
     window.show()
     sys.exit(app.exec_())
+
+
+if __name__ == "__main__":  # pragma: no cover
+    main()

bec_widgets/applications/bec_app.py

@@ -0,0 +1,84 @@
+"""
+Launcher for BEC GUI Applications
+
+Application must be located in bec_widgets/applications ;
+in order for the launcher to find the application, it has to be put in
+a subdirectory with the same name as the main Python module:
+
+/bec_widgets/applications
+    ├── alignment
+    │   └── alignment_1d
+    │       └── alignment_1d.py
+    ├── other_app
+        └── other_app.py
+
+The tree above would contain 2 applications, alignment_1d and other_app.
+
+The Python module for the application must have `if __name__ == "__main__":`
+in order for the launcher to execute it (it is run with `python -m`).
+"""
+
+import argparse
+import os
+import sys
+
+MODULE_PATH = os.path.dirname(__file__)
+
+
+def find_apps(base_dir: str) -> list[str]:
+    matching_modules = []
+
+    for root, dirs, files in os.walk(base_dir):
+        parent_dir = os.path.basename(root)
+
+        for file in files:
+            if file.endswith(".py") and file != "__init__.py":
+                file_name_without_ext = os.path.splitext(file)[0]
+
+                if file_name_without_ext == parent_dir:
+                    rel_path = os.path.relpath(root, base_dir)
+                    module_path = rel_path.replace(os.sep, ".")
+
+                    module_name = f"{module_path}.{file_name_without_ext}"
+                    matching_modules.append((file_name_without_ext, module_name))
+
+    return matching_modules
+
+
+def main():
+    parser = argparse.ArgumentParser(description="BEC application launcher")
+
+    parser.add_argument("-m", "--module", type=str, help="The module to run (string argument).")
+
+    # Add a positional argument for the module, which acts as a fallback if -m is not provided
+    parser.add_argument(
+        "positional_module",
+        nargs="?",  # This makes the positional argument optional
+        help="Positional argument that is treated as module if -m is not specified.",
+    )
+
+    args = parser.parse_args()
+    # If the -m/--module is not provided, fallback to the positional argument
+    module = args.module if args.module else args.positional_module
+
+    if module:
+        for app_name, app_module in find_apps(MODULE_PATH):
+            if module in (app_name, app_module):
+                print("Starting:", app_name)
+                python_executable = sys.executable
+
+                # Replace the current process with the new Python module
+                os.execvp(
+                    python_executable,
+                    [python_executable, "-m", f"bec_widgets.applications.{app_module}"],
+                )
+        print(f"Error: cannot find application {module}")
+
+    # display list of apps
+    print("Available applications:")
+    for app, _ in find_apps(MODULE_PATH):
+        print(f"  - {app}")
+
+
+if __name__ == "__main__":  # pragma: no cover
+    main()

pyproject.toml

@@ -48,6 +48,7 @@ Homepage = "https://gitlab.psi.ch/bec/bec_widgets"
 bw-generate-cli = "bec_widgets.cli.generate_cli:main"
 bec-gui-server = "bec_widgets.cli.server:main"
 bec-designer = "bec_widgets.utils.bec_designer:main"
+bec-app = "bec_widgets.applications.bec_app:main"
 
 [tool.hatch.build.targets.wheel]
 include = ["*"]