Road to removing qtassistant (documentation) --> C Changes required for Python HelpWindow implementation

[darshdinger]

Description of work

This work is related to issue #37248. This PR contains the majority of the C based changes that are required to help support the new Python based implementation of the HelpWindow within Mantid Workbench. The main objective is to transition away from the older qtassistant -based implementation.

Summary of work

• Removed Support for qtassistant in Documentation:

  • The DOCS_QTHELP option is now used to toggle the inclusion of the qtassistant-based help system. If DOCS_QTHELP is set to OFF, the Python-based HelpWindow will be included instead.

• Introduced a Python Bridge:

  • Added PythonHelpBridge to handle interactions between the C++ layer and the Python HelpWindow implementation. This bridge initializes the Python interpreter and invokes the relevant Python methods for showing help pages.

• Added a New HelpWindow Implementation:

  • Created PythonHelpWindow, a subclass of MantidHelpInterface, which redirects help requests to the Python layer via PythonHelpBridge. The new HelpWindow supports:
    • Displaying help pages (showPage).
    • Showing algorithm documentation.
    • Navigating to concepts, fit functions, and custom interface documentation.

• CMake Updates:

  • Modified CMakeLists.txt in multiple directories to conditionally include the Python HelpWindow (PythonHelpBridge and PythonHelpWindow) when ENABLE_QTASSISTANT is OFF.

• Code Registration:

  • Registered the new PythonHelpWindow implementation in the InterfaceManager using the REGISTER_HELPWINDOW macro.

Ref #37248

To test:

In order to test, please take the following steps:
Starting within mantid/ -

1. cmake --preset=linux
2. cd build
3. cmake . -DENABLE_QTASSISTANT=OFF
4. ninja all docs-html
5. MANTID_LOCAL_DOCS_BASE="./build/docs/html" bin/launch_mantidworkbench.sh
6. export PYTHONPATH="./qt/mantidqt/mantidqt/widgets/helpwindow:$PYTHONPATH"

Once mantid is launched, please use the F1 key to launch help window for testing purposes. Please also try checking algorithm help from within the AlgorithmDialog.

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[peterfpeterson]

Rebuilding after cmake . -DDOCS_QTHELP=off and running workbench gives me the following message when I try to start the qwebengine-based helpwindow

InterfaceManager-[Information] Offline help is not available in this version of Workbench.

turning qtassistant back on goes back to the old behavior of opening a web browser for the online help.

I was still able to directly run the bridge from my build directory using

python ~/code/mantid/qt/python/mantidqt/mantidqt/widgets/helpwindow/helpwindowbridge.py

Q: Should this be using ConfigService for information about the docs build location? docs.html.root is the key in ConfigService.

[peterfpeterson]

Adding some tests for PythonHelpWindow would be appreciated

[peterfpeterson]

Bad news. Closing mantid after the help window has been opened causes SIGSEV

FrameworkManager-[Notice] Welcome to Mantid 6.11.0.dev617
FrameworkManager-[Notice] Please cite: http://dx.doi.org/10.1016/j.nima.2014.07.029 and this release: http://dx.doi.org/10.5286/Software/Mantid
Help window closed.
Cleaning up Help Window resources.
Received signal: SIGSEGV
Segmentation fault

The shutdown needs to be investigated

[darshdinger]

Uh oh... let me see if I can figure out why this is happening.

[peterfpeterson]

Works as expected and closes cleanly