QFace IDL for Visual Studio Code
Language support for the QFace interface definition language —
the IDL used by Qt Interface Framework and the
qface code generator — in Visual Studio Code.
Syntax highlighting works out of the box, with no dependencies. Diagnostics are
opt-in: they come from a Python language server that reuses QFace's own ANTLR
parser and domain model, so what the editor flags is what the real generator
sees.
Features
Syntax highlighting
Full TextMate grammar for .qface files, covering declarations
(module, import, interface, struct, enum, flag), members
(property, readonly, signal, extends), primitive types
(int, real, string, bool, var, void), container types
(list<>, map<>, model<>), string and numeric literals, comments, and
QFace annotations (@brief, @description, @see, and custom @key: value
tags).
Editor behaviour
Comment toggling, bracket matching and auto-closing, indentation rules for
block bodies, and // #region / // #endregion folding, via
language-configuration.json.
Diagnostics (opt-in)
Once enabled via qface.server.enable, the language server validates open
documents as you type and reports:
- Syntax errors — surfaced directly from QFace's ANTLR parser, at the
reported line and column.
- Unresolved type references — a property, operation return type,
operation parameter, signal parameter, or struct field that names a complex
type which cannot be resolved in the module or its imports. Nested container
types such as
list<Foo> and map<Bar> are unwrapped and checked on their
leaf type.
Diagnostics are reported under the qface source, so they can be filtered in
the Problems panel. See Enabling diagnostics for setup.
Requirements
Syntax highlighting and the editor behaviour described above have no
dependencies and work as soon as the extension is installed.
Diagnostics are opt-in. They run in a Python language server that the
extension does not start unless you enable it, so installing this extension
never requires Python.
Enabling diagnostics
Install the server's dependencies into a Python 3.9 or newer interpreter:
pip install pygls qface
Then set qface.server.enable to true. Unless python on your PATH is the
interpreter you just installed into, also point qface.pythonPath at the right
one. The server starts as soon as either setting changes — no window reload
needed.
If it cannot be started, the extension shows a warning with links to the
relevant setting and to its log, and syntax highlighting keeps working.
Extension settings
| Setting |
Type |
Default |
Description |
qface.pythonPath |
string |
python |
Path to the Python interpreter used to run the language server. Use an absolute path to select a virtual environment, e.g. ${workspaceFolder}/.venv/Scripts/python.exe on Windows or ${workspaceFolder}/.venv/bin/python elsewhere. |
qface.server.enable |
boolean |
false |
Set to true to start the Python language server and get diagnostics. Requires a working qface.pythonPath. |
qface.trace.server |
enum |
off |
Log LSP traffic between VS Code and the server to the QFace Language Server output channel. Useful values: messages, verbose. |
Commands
| Command |
Description |
QFace: Restart Language Server |
Stops and restarts the server process. |
The server also restarts automatically when qface.pythonPath or
qface.server.enable changes.
Troubleshooting
No diagnostics appear. First check that qface.server.enable is true — it
is false by default. If it is enabled, open the QFace Language Server output
channel (View → Output, then pick the channel) and check for a startup error.
The most common cause is an interpreter without pygls or qface installed.
Verify it independently:
python -c "import pygls, qface; print('ok')"
Diagnostics look wrong or incomplete. Set qface.trace.server to
verbose, reproduce the problem, and attach the output channel contents to a
bug report.
Status
Under active development. Syntax highlighting and diagnostics are usable;
hover, completion, go-to-definition, and find-references are not implemented
yet. Issues and pull requests are welcome.
License
MIT. Third-party components and their licenses are listed in
THIRD-PARTY-NOTICES.md.
