Add Python typings for Rust declared types (#7575)

This comes with a bump of the Python version to 3.11
due to the need for typing.Self.

api/python/Cargo.toml

@@ -15,7 +15,11 @@ rust-version.workspace = true
 
 [lib]
 path = "lib.rs"
-crate-type = ["cdylib"]
+crate-type = ["cdylib", "rlib"]
+
+[[bin]]
+name = "stub-gen"
+path = "stub-gen/main.rs"
 
 [features]
 default = ["backend-winit", "renderer-femtovg", "renderer-software", "backend-qt", "accessibility"]
@@ -46,6 +50,7 @@ indexmap = { version = "2.1.0" }
 chrono = "0.4"
 spin_on = { workspace = true }
 css-color-parser2 = { workspace = true }
+pyo3-stub-gen = { version = "0.7.0", default-features = false }
 
 [package.metadata.maturin]
 python-source = "slint"

api/python/brush.rs

@@ -2,9 +2,36 @@
 // SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
 
 use pyo3::prelude::*;
+use pyo3_stub_gen::{derive::gen_stub_pyclass, derive::gen_stub_pymethods, impl_stub_type};
 
 use crate::errors::PyColorParseError;
 
+#[gen_stub_pyclass]
+#[pyclass]
+#[derive(FromPyObject)]
+struct RgbaColor {
+    #[pyo3(get, set)]
+    red: u8,
+    #[pyo3(get, set)]
+    green: u8,
+    #[pyo3(get, set)]
+    blue: u8,
+    #[pyo3(get, set)]
+    alpha: u8,
+}
+
+#[gen_stub_pyclass]
+#[pyclass]
+#[derive(FromPyObject)]
+struct RgbColor {
+    #[pyo3(get, set)]
+    red: u8,
+    #[pyo3(get, set)]
+    green: u8,
+    #[pyo3(get, set)]
+    blue: u8,
+}
+
 #[derive(FromPyObject)]
 enum PyColorInput {
     ColorStr(String),
@@ -29,12 +56,16 @@ enum PyColorInput {
     },
 }
 
+impl_stub_type!(PyColorInput = String | RgbaColor | RgbColor);
+
+#[gen_stub_pyclass]
 #[pyclass(name = "Color")]
 #[derive(Clone)]
 pub struct PyColor {
     pub color: slint_interpreter::Color,
 }
 
+#[gen_stub_pymethods]
 #[pymethods]
 impl PyColor {
     #[new]
@@ -124,11 +155,15 @@ enum PyBrushInput {
     SolidColor(PyColor),
 }
 
+impl_stub_type!(PyBrushInput = PyColor);
+
+#[gen_stub_pyclass]
 #[pyclass(name = "Brush")]
 pub struct PyBrush {
     pub brush: slint_interpreter::Brush,
 }
 
+#[gen_stub_pymethods]
 #[pymethods]
 impl PyBrush {
     #[new]

api/python/image.rs

@@ -2,14 +2,17 @@
 // SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
 
 use pyo3::prelude::*;
+use pyo3_stub_gen::{derive::gen_stub_pyclass, derive::gen_stub_pymethods};
 
 /// Image objects can be set on Slint Image elements for display. Construct Image objects from a path to an
 /// image file on disk, using `Image.load_from_path`.
+#[gen_stub_pyclass]
 #[pyclass(unsendable, name = "Image")]
 pub struct PyImage {
     pub image: slint_interpreter::Image,
 }
 
+#[gen_stub_pymethods]
 #[pymethods]
 impl PyImage {
     #[new]
@@ -37,8 +40,8 @@ impl PyImage {
 
     /// The path of the image if it was loaded from disk, or None.
     #[getter]
-    fn path(&self) -> PyResult<Option<&std::path::Path>> {
-        Ok(self.image.path())
+    fn path(&self) -> PyResult<Option<std::path::PathBuf>> {
+        Ok(self.image.path().map(|p| p.to_path_buf()))
     }
 
     /// Loads the image from the specified path. Returns None if the image can't be loaded.
@@ -50,8 +53,8 @@ impl PyImage {
 
     /// Creates a new image from a string that describes the image in SVG format.
     #[staticmethod]
-    fn load_from_svg_data(data: &[u8]) -> Result<Self, crate::errors::PyLoadImageError> {
-        let image = slint_interpreter::Image::load_from_svg_data(data)?;
+    fn load_from_svg_data(data: Vec<u8>) -> Result<Self, crate::errors::PyLoadImageError> {
+        let image = slint_interpreter::Image::load_from_svg_data(&data)?;
         Ok(Self { image })
     }
 }

api/python/lib.rs

@@ -1,6 +1,8 @@
 // Copyright © SixtyFPS GmbH <info@slint.dev>
 // SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
 
+use pyo3_stub_gen::define_stub_info_gatherer;
+
 mod image;
 mod interpreter;
 use interpreter::{CompilationResult, Compiler, PyDiagnostic, PyDiagnosticLevel, PyValueType};
@@ -53,3 +55,5 @@ fn slint(_py: Python<'_>, m: &Bound<'_, PyModule>) -> PyResult<()> {
 
     Ok(())
 }
+
+define_stub_info_gatherer!(stub_info);

api/python/noxfile.py

@@ -3,7 +3,7 @@
 
 import nox
 
-@nox.session(python="3.10")
+@nox.session(python="3.11")
 def python(session: nox.Session):
     session.env["MATURIN_PEP517_ARGS"] = "--profile=dev"
     session.install(".[dev]")

api/python/pyproject.toml

@@ -8,7 +8,7 @@ build-backend = "maturin"
 [project]
 name = "slint"
 version = "1.10.0a1"
-requires-python = ">= 3.10"
+requires-python = ">= 3.11"
 authors = [
     {name = "Slint Team", email = "info@slint.dev"},
 ]

api/python/slint/__init__.pyi

@@ -0,0 +1,134 @@
+# Copyright © SixtyFPS GmbH <info@slint.dev>
+# SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
+
+# This file is automatically generated by pyo3_stub_gen
+# ruff: noqa: E501, F401
+
+import builtins
+import datetime
+import os
+import pathlib
+import typing
+from typing import Self
+from enum import Enum, auto
+
+
+class RgbColor:
+    red: builtins.int
+    green: builtins.int
+    blue: builtins.int
+
+class RgbaColor:
+    red: builtins.int
+    green: builtins.int
+    blue: builtins.int
+    alpha: builtins.int
+
+
+class Color:
+    red: builtins.int
+    green: builtins.int
+    blue: builtins.int
+    alpha: builtins.int
+    def __new__(cls,maybe_value:typing.Optional[builtins.str | RgbaColor | RgbColor]): ...
+    def brighter(self, factor:builtins.float) -> Self:
+        ...
+
+    def darker(self, factor:builtins.float) -> Self:
+        ...
+
+    def transparentize(self, factor:builtins.float) -> Self:
+        ...
+
+    def mix(self, other:Self, factor:builtins.float) -> Self:
+        ...
+
+    def with_alpha(self, alpha:builtins.float) -> Self:
+        ...
+
+    def __str__(self) -> builtins.str:
+        ...
+
+    def __eq__(self, other:Self) -> builtins.bool:
+        ...
+
+
+
+class Brush:
+    color: Color
+    def __new__(cls,maybe_value:typing.Optional[Color]): ...
+    def is_transparent(self) -> builtins.bool:
+        ...
+
+    def is_opaque(self) -> builtins.bool:
+        ...
+
+    def brighter(self, factor:builtins.float) -> Self:
+        ...
+
+    def darker(self, factor:builtins.float) -> Self:
+        ...
+
+    def transparentize(self, amount:builtins.float) -> Self:
+        ...
+
+    def with_alpha(self, alpha:builtins.float) -> Self:
+        ...
+
+    def __eq__(self, other:Self) -> builtins.bool:
+        ...
+
+
+class Image:
+    r"""
+    Image objects can be set on Slint Image elements for display. Construct Image objects from a path to an
+    image file on disk, using `Image.load_from_path`.
+    """
+    size: tuple[builtins.int, builtins.int]
+    width: builtins.int
+    height: builtins.int
+    path: typing.Optional[builtins.str]
+    def __new__(cls,): ...
+    @staticmethod
+    def load_from_path(path:builtins.str | os.PathLike | pathlib.Path) -> Self:
+        r"""
+        Loads the image from the specified path. Returns None if the image can't be loaded.
+        """
+        ...
+
+    @staticmethod
+    def load_from_svg_data(data:typing.Sequence[builtins.int]) -> Self:
+        r"""
+        Creates a new image from a string that describes the image in SVG format.
+        """
+        ...
+
+
+class TimerMode(Enum):
+    SingleShot = auto()
+    Repeated = auto()
+
+
+class Timer:
+    def __new__(cls,): ...
+    def start(self, mode:TimerMode, interval:datetime.timedelta, callback:typing.Any) -> None:
+        ...
+
+    @staticmethod
+    def single_shot(duration:datetime.timedelta, callback:typing.Any) -> None:
+        ...
+
+    def stop(self) -> None:
+        ...
+
+    def restart(self) -> None:
+        ...
+
+    def running(self) -> builtins.bool:
+        ...
+
+    def set_interval(self, interval:datetime.timedelta) -> None:
+        ...
+
+
+

api/python/stub-gen/main.rs

@@ -0,0 +1,11 @@
+// Copyright © SixtyFPS GmbH <info@slint.dev>
+// SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
+
+use pyo3_stub_gen::Result;
+
+fn main() -> Result<()> {
+    // `stub_info` is a function defined by `define_stub_info_gatherer!` macro.
+    let stub = slint_python::stub_info()?;
+    stub.generate()?;
+    Ok(())
+}

api/python/timer.rs

@@ -2,8 +2,12 @@
 // SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
 
 use pyo3::prelude::*;
+use pyo3_stub_gen::{
+    derive::gen_stub_pyclass, derive::gen_stub_pyclass_enum, derive::gen_stub_pymethods,
+};
 
 #[derive(Copy, Clone)]
+#[gen_stub_pyclass_enum]
 #[pyclass(name = "TimerMode")]
 pub enum PyTimerMode {
     /// A SingleShot timer is fired only once.
@@ -21,11 +25,13 @@ impl From<PyTimerMode> for i_slint_core::timers::TimerMode {
     }
 }
 
+#[gen_stub_pyclass]
 #[pyclass(name = "Timer", unsendable)]
 pub struct PyTimer {
     timer: i_slint_core::timers::Timer,
 }
 
+#[gen_stub_pymethods]
 #[pymethods]
 impl PyTimer {
     #[new]