CXX-Qt

https://docs.rs/cxx-qt/0.7.2/
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CXX-Qt is a framework for generating QObjects from Rust, enabling seamless integration between Rust...
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### Minimal Rust Example for cxx_qt::bridge with Custom Constructor

Source: https://docs.rs/cxx-qt/0.7.2/src/cxx_qt/lib.rs

Demonstrates the minimal setup for the `#[cxx_qt::bridge]` macro, including defining a Rust struct and implementing a custom constructor for a QObject. This example shows how to specify constructor arguments and initialize the Rust struct.

```rust
#[cxx_qt::bridge]
mod qobject {
    extern "RustQt" {
        #[qobject]
        type MyStruct = super::MyStructRust;
    }

    // Declare that we want to use a custom constructor
    // Note that the arguments must be a tuple of CXX types.
    // Any associated types that aren't included here are assumed to be `()`.
    impl cxx_qt::Constructor<(i32, String), NewArguments=(i32, String)> for MyStruct {}
}

// Struct without `Default` implementation
pub struct MyStructRust {
    pub integer: i32,
    pub string: String
}

impl cxx_qt::Constructor<(i32, String)> for qobject::MyStruct {
    type BaseArguments = (); // Will be passed to the base class constructor
    type InitializeArguments = (); // Will be passed to the "initialize" function
    type NewArguments = (i32, String); // Will be passed to the "new" function

    fn route_arguments(args: (i32, String)) -> (
        Self::NewArguments,
        Self::BaseArguments,
        Self::InitializeArguments
    ) {
        (args, (), ())
    }

    fn new((integer, string): (i32, String)) -> MyStructRust {
        MyStructRust {
            integer,
            string
        }
    }
}

# // Note that we need a fake main function for doc tests to build.
# fn main() {}

```

--------------------------------

### Example: Using Initialize Trait with CxxQt Bridge in Rust

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/trait.Initialize

This example demonstrates how to use the `Initialize` trait within a CXX-Qt bridge. It shows the necessary `#[cxx_qt::bridge]` macro, the definition of a QObject, and how to implement the `Initialize` trait for custom initialization logic, such as setting up change notifications.

```Rust
#[cxx_qt::bridge]
mod qobject {
    extern "RustQt" {
        #[qobject]
        #[qproperty(i32, integer)]
        type MyStruct = super::MyStructRust;
    }

    // Remember to tell the bridge about the default constructor
    impl cxx_qt::Constructor<()> for MyStruct {}
    // or
    impl cxx_qt::Initialize for MyStruct {}
}

// Make sure the inner Rust struct implements `Default`
#[derive(Default)]
pub struct MyStructRust {
    integer: i32,
}

impl cxx_qt::Initialize for qobject::MyStruct {
    fn initialize(self: core::pin::Pin<&mut Self>) {
        self.on_integer_changed(|qobject| {
            println!("New integer value: {}", qobject.integer);
        }).release();
    }
}
```

--------------------------------

### Example: Safe Queueing with is_destroyed (Rust)

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/struct.CxxQtThread

Illustrates a common pattern for using `is_destroyed` before queuing, highlighting the potential race condition. It shows how a QObject might be destroyed between the check and the queue call, leading to a panic.

```rust
if !thread.is_destroyed() {
    thread.queue(/*...*/).unwrap();
}

```

--------------------------------

### Rust Example: Threading QObjects with cxx-qt

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/trait.Threading

Demonstrates how to implement and use the `Threading` trait in Rust with CXX-Qt. It shows creating a QObject, implementing a thread-safe invokable method (`say_hello`), and using `CxxQtThread` to queue operations on the Qt event loop from a background thread.

```Rust
#[cxx_qt::bridge]
mod qobject {
    extern "RustQt" {
        #[qobject]
        type MyStruct = super::MyStructRust;

       #[qinvokable]
        fn say_hello(self: Pin<&mut MyStruct>);
    }

    impl cxx_qt::Threading for MyStruct {}
}

use cxx_qt::Threading;

#[derive(Default)]
pub struct MyStructRust;

impl qobject::MyStruct {
    pub fn say_hello(self: core::pin::Pin<&mut Self>) {
        let qt_thread = self.qt_thread();

        // Start a background thread that doesn't block the invokable
        std::thread::spawn(move || {
            std::thread::sleep(std::time::Duration::from_secs(1));

            // Say hello on the Qt event loop
            qt_thread.queue(|_| {
                println!("Hello");
            }).unwrap();
        });
    }
}
```

--------------------------------

### Define QObject with Custom Base Class in Rust

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/attr.qobject

This example demonstrates how to specify a custom base class for a QObject using the `#[base]` attribute within the `#[qobject]` macro. It also shows how to include necessary C++ headers using `include!` for the custom base class. The example uses `QStringListModel` as a custom base class.

```rust
#[cxx_qt::bridge]
mod my_object {
    extern "RustQt" {
        #[qobject]
        #[base = QStringListModel]
        type MyModel = super::MyModelRust;
    }

    unsafe extern "C++" {
        include!(<QtCore/QStringListModel>);
        type QStringListModel;
    }
}

#[derive(Default)]
pub struct MyModelRust;

```

--------------------------------

### Example: Loop with is_destroyed (Rust)

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/struct.CxxQtThread

Demonstrates using `is_destroyed` to control a loop for continuous queueing of operations. The `ok()` method is used on the result of `queue` to handle potential failures gracefully without panicking.

```rust
while !thread.is_destroyed() {
    thread.queue(/*...*/).ok();
}

```

--------------------------------

### Rust QObject Generation with #[bridge] Macro

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/attr.bridge

This Rust code snippet demonstrates the use of the `#[bridge]` attribute macro from the `cxx-qt` crate. It defines a Rust struct `MyObjectRust` and uses the macro to generate a corresponding QObject named `MyObject` within a specified namespace. The example also shows how to define and implement a `#[qinvokable]` function for the generated QObject.

```Rust
#[cxx_qt::bridge(namespace = "cxx_qt::my_object")]
mod qobject {
    extern "RustQt" {
        #[qobject]
        type MyObject = super::MyObjectRust;

        #[qinvokable]
        fn invokable(self: &MyObject, a: i32, b: i32) -> i32;
    }
}

#[derive(Default)]
pub struct MyObjectRust;

impl qobject::MyObject {
    fn invokable(&self, a: i32, b: i32) -> i32 {
        a + b
    }
}
```

--------------------------------

### Define QObject with #[qobject] Macro in Rust

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/attr.qobject

The `#[qobject]` macro is used within a `cxx_qt::bridge` to designate a Rust struct as a QObject. This macro should not be used independently. It requires the `cxx_qt::bridge` to function correctly. The example shows a basic QObject definition.

```rust
#[cxx_qt::bridge]
mod my_object {
    extern "RustQt" {
        #[qobject]
        type MyObject = super::MyObjectRust;
    }
}

#[derive(Default)]
pub struct MyObjectRust;

```

--------------------------------

### Constructor Trait Documentation

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/trait.Constructor

Documentation for the `Constructor` trait, detailing its purpose, associated types, and methods for custom QObject construction.

```APIDOC
## Trait: Constructor<Arguments>

### Description
This trait can be implemented on any `CxxQtType` to define a custom constructor in C++ for the QObject. The `Arguments` must be a tuple of CXX types that will be the arguments to the constructor in C++.

If this trait is implemented for a given `CxxQtType`, it must also be declared inside the `cxx_qt::bridge` macro. Note that declaring an implementation of this trait will stop CXX-Qt from generating a default constructor. Therefore, an implementation of `Default` is no longer required for the Rust type.

### Associated Types

#### `type NewArguments`

*   **Description**: The arguments that are passed to the `new()` function to construct the inner Rust struct. This must be a tuple of CXX compatible types. This way QObjects can be constructed that need additional arguments for constructing the inner Rust type.

#### `type BaseArguments`

*   **Description**: Arguments that will be passed to the base class constructor.

#### `type InitializeArguments`

*   **Description**: Arguments that will be passed to the `initialize` function.

### Methods

#### `fn route_arguments(arguments: Arguments) -> (Self::NewArguments, Self::BaseArguments, Self::InitializeArguments)`

*   **Description**: Routes the incoming `Arguments` tuple into the specific argument types required for `new()`, the base class constructor, and the `initialize` function.

#### `fn new(arguments: Self::NewArguments) -> <Self as CxxQtType>::Rust`

*   **Description**: Constructs the inner Rust struct using the provided `NewArguments`.

#### `fn initialize(self: Pin<&mut Self>, arguments: Self::InitializeArguments)` (Provided)

*   **Description**: Allows running code from the context of the QObject itself, typically for initialization tasks before the QObject is fully ready. It is given a pinned mutable self reference to the QObject and the list of `InitializeArguments`.

### Pseudo Code for generated C++ Constructor
```cpp
class MyCxxQtType : public QObject {
    public:
        MyCxxQtType(Arguments... args)
            : QObject(Constructor::route_arguments(args).BaseArguments)
            , m_rust(Constructor::new(Constructor::route_arguments(args).NewArguments))
        {
            Constructor::initialize(*this, Constructor::route_arguments(args).InitializeArguments);
        }
}
```
*Note: In reality, `route_arguments` will only be called once and all arguments will be moved, never copied.*

### Minimal Example
```rust
#[cxx_qt::bridge]
mod qobject {
    extern "RustQt" {
        #[qobject]
        type MyStruct = super::MyStructRust;
    }

    // Declare that we want to use a custom constructor
    // Note that the arguments must be a tuple of CXX types.
    // Any associated types that aren't included here are assumed to be `()`.
    impl cxx_qt::Constructor<(i32, String), NewArguments=(i32, String)> for MyStruct {}
}

// Struct without `Default` implementation
pub struct MyStructRust {
    pub integer: i32,
    pub string: String
}

impl cxx_qt::Constructor<(i32, String)> for qobject::MyStruct {
    type BaseArguments = (); // Will be passed to the base class constructor
    type InitializeArguments = (); // Will be passed to the "initialize" function
    type NewArguments = (i32, String); // Will be passed to the "new" function

    fn route_arguments(args: (i32, String)) -> (
        Self::NewArguments,
        Self::BaseArguments,
        Self::InitializeArguments
    ) {
        (args, (), ())
    }

    fn new((integer, string): (i32, String)) -> MyStructRust {
        MyStructRust {
            integer,
            string
        }
    }
}
```

### Using the `Initialize` trait

The QML engine creates QML elements using their default constructor, so for most QML types only the `initialize` part of the constructor is of interest. To reduce the boilerplate of this use-case, CXX-Qt provides the `Initialize` trait. If a QObject implements the `Initialize` trait, and the inner Rust struct is `Default`-constructible, it will automatically implement `cxx_qt::Constructor<()>`. Additionally, implementing `impl cxx_qt::Initialize` will act as shorthand for `cxx_qt::Constructor<()>`. 
```

--------------------------------

### Structs

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/all

Details on the available structs within the cxx-qt 0.7.2 crate.

```APIDOC
## Structs

### Description
This section lists and describes the structs available in the cxx-qt 0.7.2 crate.

### Structs List

*   **ConnectionType**: Represents a connection type.
*   **CxxQtThread**: Represents a thread managed by cxx-qt.
*   **QMetaObjectConnection**: Represents a connection to a Qt meta-object.
*   **QMetaObjectConnectionGuard**: A guard for managing QMetaObjectConnection lifetime.
```

--------------------------------

### cxx-qt Enums

Source: https://docs.rs/cxx-qt/0.7.2/index

Documentation for the enums provided by the cxx-qt crate.

```APIDOC
## Enums

### ThreadingQueueError

Errors that can occur from CXX-Qt
```

--------------------------------

### Pseudo Code for Generated C++ Constructor using Constructor Trait

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/trait.Constructor

This pseudo-code illustrates how the `cxx_qt::Constructor` trait is conceptually translated into a C++ constructor for a QObject. It shows how arguments are routed, used to construct the inner Rust struct, and passed to the `initialize` function.

```cpp
class MyCxxQtType : public QObject {
    public:
        MyCxxQtType(Arguments... args)
            : QObject(Constructor::route_arguments(args).BaseArguments)
            , m_rust(Constructor::new(Constructor::route_arguments(args).NewArguments))
        {
            Constructor::initialize(*this, Constructor::route_arguments(args).InitializeArguments);
        }
}

```

--------------------------------

### Attribute Macros

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/all

Details on the available attribute macros within the cxx-qt 0.7.2 crate.

```APIDOC
## Attribute Macros

### Description
This section lists and describes the attribute macros available in the cxx-qt 0.7.2 crate.

### Attribute Macros List

*   **bridge**: An attribute macro for bridging Rust and C++ code.
*   **qobject**: An attribute macro for defining Qt QObjects in Rust.
```

--------------------------------

### Initialize QObject with CXX-Qt initialize()

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/trait.Constructor

The `initialize` function is called after the QObject's members are initialized, serving as the equivalent of a C++ constructor body. By default, this function performs no action.

```rust
fn initialize(self: Pin<&mut Self>, arguments: Self::InitializeArguments)

This function is called to initialize the QObject. After the members of the QObject is initialized, this function is called. This is equivalent to the body of the constructor in C++.

##### §Default
By default, this function does nothing
```

--------------------------------

### Default Constructor Arguments for CXX-Qt Implementor

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/trait.Constructor

This implementation provides default types for `NewArguments`, `BaseArguments`, and `InitializeArguments`, all set to the empty tuple `()`, indicating no arguments are needed for these by default.

```rust
impl<T> Constructor<()> for T
where T: Initialize,
      T::Rust: Default,

#### type NewArguments = ()

#### type BaseArguments = ()

#### type InitializeArguments = ()
```

--------------------------------

### Enums

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/all

Details on the available enums within the cxx-qt 0.7.2 crate.

```APIDOC
## Enums

### Description
This section lists and describes the enums available in the cxx-qt 0.7.2 crate.

### Enums List

*   **ThreadingQueueError**: An enum representing errors that can occur with threading queues.
```

--------------------------------

### Implement cxx_qt::Constructor Trait for Custom QObject Construction

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/trait.Constructor

This Rust code demonstrates how to implement the `cxx_qt::Constructor` trait to define a custom constructor for a QObject. It specifies the arguments for the C++ constructor, the arguments for the Rust `new` function, and arguments for the `initialize` function. The `route_arguments` function maps the incoming arguments to these specific types.

```rust
#[cxx_qt::bridge]
mod qobject {
    extern "RustQt" {
        #[qobject]
        type MyStruct = super::MyStructRust;
    }

    // Declare that we want to use a custom constructor
    // Note that the arguments must be a tuple of CXX types.
    // Any associated types that aren't included here are assumed to be `()`.
    impl cxx_qt::Constructor<(i32, String), NewArguments=(i32, String)> for MyStruct {}
}

// Struct without `Default` implementation
pub struct MyStructRust {
    pub integer: i32,
    pub string: String
}

impl cxx_qt::Constructor<(i32, String)> for qobject::MyStruct {
    type BaseArguments = (); // Will be passed to the base class constructor
    type InitializeArguments = (); // Will be passed to the "initialize" function
    type NewArguments = (i32, String); // Will be passed to the "new" function

    fn route_arguments(args: (i32, String)) -> (
        Self::NewArguments,
        Self::BaseArguments,
        Self::InitializeArguments
    ) {
        (args, (), ())
    }

    fn new((integer, string): (i32, String)) -> MyStructRust {
        MyStructRust {
            integer,
            string
        }
    }
}

```

--------------------------------

### Traits

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/all

Details on the available traits within the cxx-qt 0.7.2 crate.

```APIDOC
## Traits

### Description
This section lists and describes the traits available in the cxx-qt 0.7.2 crate.

### Traits List

*   **Constructor**: A trait for defining constructors.
*   **CxxQtType**: A trait for types managed by cxx-qt.
*   **Initialize**: A trait for initialization logic.
*   **Threading**: A trait related to threading operations.
```

--------------------------------

### Rust: Write CxxQt Headers

Source: https://docs.rs/cxx-qt/0.7.2/src/cxx_qt/lib.rs

This function writes the necessary CxxQt header files to a specified directory. It ensures the directory exists and then copies predefined header content into it. This is crucial for the CXX-Qt bridge to function correctly.

```rust
pub fn write_headers(directory: impl AsRef<Path>) {
    let directory = directory.as_ref();
    std::fs::create_dir_all(directory).expect("Could not create cxx-qt header directory");
    for (file_contents, file_name) in [
        (include_str!("../include/connection.h"), "connection.h"),
        (
            include_str!("../include/signalhandler.h"),
            "signalhandler.h",
        ),
        (include_str!("../include/thread.h"), "thread.h"),
        (include_str!("../include/threading.h"), "threading.h"),
        (include_str!("../include/type.h"), "type.h"),
    ] {
        let h_path = format!("{}/{file_name}", directory.display());
        let mut header = File::create(h_path).expect("Could not create cxx-qt header");
        write!(header, "{file_contents}").expect("Could not write cxx-qt header");
    }
}
```

--------------------------------

### Route Arguments with CXX-Qt

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/trait.Constructor

The `route_arguments` function is called by CXX-Qt to distribute arguments to their appropriate destinations. This allows for splitting constructor arguments without extra copying.

```rust
fn route_arguments( arguments: Arguments, ) -> (Self::NewArguments, Self::BaseArguments, Self::InitializeArguments)

This function is called by CXX-Qt to route the arguments to the correct places.
Using this function, you can split up the arguments required by the QObject constructor without additional copies.
```

--------------------------------

### Clone Implementation for CxxQtThread (Rust)

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/struct.CxxQtThread

Provides the `Clone` trait implementation for `CxxQtThread`, allowing for the creation of duplicate instances. This is useful when multiple parts of the code need to interact with the same threaded QObject.

```rust
impl<T> Clone for CxxQtThread<T>
where T: Threading,
{
    fn clone(&self) -> Self
}

```

--------------------------------

### Implement Initialize Trait for CxxQtType in Rust

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/trait.Initialize

The `Initialize` trait in cxx-qt allows for automatic definition of a default constructor that calls an `initialize` function. This is useful for setting up QObjects after they are constructed. The implementation can be done directly or via a shorthand `impl cxx_qt::Initialize for ... {}`.

```Rust
pub trait Initialize: CxxQtType {
    // Required method
    fn initialize(self: Pin<&mut Self>);
}
```

--------------------------------

### Rust: Initialize QObject

Source: https://docs.rs/cxx-qt/0.7.2/src/cxx_qt/lib.rs

This trait is implemented on any CxxQtType to define an initialization function for QObjects. It's called after the QObject's members are initialized and is equivalent to the body of a C++ constructor. By default, this function does nothing.

```rust
pub trait Initialize: CxxQtType {
    /// This function is called to initialize the QObject after construction.
    fn initialize(self: core::pin::Pin<&mut Self>);
}
```

--------------------------------

### Convert QMetaObjectConnection to QMetaObjectConnectionGuard in Rust

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/struct.QMetaObjectConnectionGuard

Implements the From trait to allow conversion from a QMetaObjectConnection to a QMetaObjectConnectionGuard. This facilitates the creation of the guard from an existing connection.

```rust
fn from(connection: QMetaObjectConnection) -> Self
```

--------------------------------

### QMetaObjectConnectionGuard for Connection Management in Rust

Source: https://docs.rs/cxx-qt/0.7.2/src/cxx_qt/connectionguard.rs

The `QMetaObjectConnectionGuard` struct manages the lifecycle of a signal-slot connection. It is created from a `QMetaObjectConnection` and automatically disconnects the connection when the guard is dropped. This ensures that connections are properly cleaned up, preventing potential memory leaks or dangling pointers. The `release` method allows for manual control over the connection's lifecycle.

```rust
use crate::QMetaObjectConnection;

/// Represents a guard to a signal-slot (or signal-functor) connection.
///
/// This struct can be created from a [QMetaObjectConnection].
///
/// Note that when this struct is dropped the connection is disconnected.
/// So to keep a connection active either hold onto the struct for the duration
/// that the connection should be active or call `release`, hence the `#[must_use]`.
#[must_use]
pub struct QMetaObjectConnectionGuard {
    connection: QMetaObjectConnection,
}

impl From<QMetaObjectConnection> for QMetaObjectConnectionGuard {
    fn from(connection: QMetaObjectConnection) -> Self {
        Self { connection }
    }
}

impl Drop for QMetaObjectConnectionGuard {
    /// Disconnect and deconstruct the connection
    fn drop(&mut self) {
        self.connection.disconnect();
    }
}

impl QMetaObjectConnectionGuard {
    /// Release the connection without disconnecting
    pub fn release(mut self) -> QMetaObjectConnection {
        // Take the connection as our Drop implementation disconnects automatically
        // whereas we just want to release
        core::mem::take(&mut self.connection)
    }
}
```

--------------------------------

### ConnectionType Constants for Signal-Slot Connections in Rust

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/struct.ConnectionType

Provides constants for different connection types in cxx-qt's `ConnectionType` enum. These constants define how signals are connected to slots, specifying immediate invocation, queued execution, or blocking behavior.

```rust
pub const AutoConnection: Self
If the receiver lives in the thread that emits the signal, Qt::DirectConnection is used. Otherwise, Qt::QueuedConnection is used. The connection type is determined when the signal is emitted.
```

```rust
pub const DirectConnection: Self
The slot is invoked immediately when the signal is emitted. The slot is executed in the signalling thread.
```

```rust
pub const QueuedConnection: Self
The slot is invoked when control returns to the event loop of the receiver’s thread. The slot is executed in the receiver’s thread.
```

```rust
pub const BlockingQueuedConnection: Self
Same as Qt::QueuedConnection, except that the signalling thread blocks until the slot returns. This connection must not be used if the receiver lives in the signalling thread, or else the application will deadlock.
```

--------------------------------

### CxxQtType Trait

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/trait.CxxQtType

Details about the CxxQtType trait, including its associated types and methods.

```APIDOC
## Trait CxxQtType

### Description
This trait is automatically implemented for all QObject types generated by CXX-Qt. It provides information about the inner Rust struct that is wrapped by the QObject, as well as the methods that Cxx-Qt will generate for the QObject.

## Associated Types

### type Rust

*   **Description**: The Rust type that this QObject is wrapping.

## Methods

### fn rust(&self) -> &Self::Rust

*   **Description**: Retrieve an immutable reference to the Rust struct backing this C++ object.

### fn rust_mut(self: Pin<&mut Self>) -> Pin<&mut Self::Rust>

*   **Description**: Retrieve a mutable reference to the Rust struct backing this C++ object.
```

--------------------------------

### Sync Implementation for CxxQtThread (Rust)

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/struct.CxxQtThread

Marks `CxxQtThread` as `Sync`, indicating that it can be safely shared between threads. This allows multiple threads to access the same `CxxQtThread` instance concurrently.

```rust
impl<T> Sync for CxxQtThread<T>
where T: Threading,
{
}

```

--------------------------------

### Rust: Implement Default Constructor for CxxQtType

Source: https://docs.rs/cxx-qt/0.7.2/src/cxx_qt/lib.rs

This trait implementation automatically defines a default constructor for CxxQtType. It calls the `initialize` function after constructing a default Rust struct. Ensure this is declared within the CXX-Qt bridge. The `Initialize` trait acts as a shorthand for this.

```rust
impl<T> Constructor<()> for T
where
    T: Initialize,
    T::Rust: Default,
{
    type NewArguments = ();
    type BaseArguments = ();
    type InitializeArguments = ();

    fn new(_arguments: ()) -> <Self as CxxQtType>::Rust {
        <Self as CxxQtType>::Rust::default()
    }

    fn route_arguments(
        _arguments: (),
    ) -> (
        Self::NewArguments,
        Self::BaseArguments,
        Self::InitializeArguments,
    ) {
        ((), (), ())
    }

    fn initialize(self: core::pin::Pin<&mut Self>, _arguments: Self::InitializeArguments) {
        Self::initialize(self);
    }
}
```

--------------------------------

### Define Constructor Trait for cxx_qt::Constructor

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/trait.Constructor

This Rust code defines the `Constructor` trait, which is central to customizing QObject construction in CXX-Qt. It outlines the associated types `NewArguments`, `BaseArguments`, and `InitializeArguments`, and the required methods `route_arguments` and `new`.

```rust
pub trait Constructor<Arguments>: CxxQtType {
    type NewArguments;
    type BaseArguments;
    type InitializeArguments;

    // Required methods
    fn route_arguments(
        arguments: Arguments,
    ) -> (Self::NewArguments, Self::BaseArguments, Self::InitializeArguments);
    fn new(arguments: Self::NewArguments) -> <Self as CxxQtType>::Rust;

    // Provided method
    fn initialize(self: Pin<&mut Self>, arguments: Self::InitializeArguments) { ... }
}

```

--------------------------------

### Implement CxxQtSignalHandler Struct

Source: https://docs.rs/cxx-qt/0.7.2/src/cxx_qt/signalhandler.rs

Implements the `CxxQtSignalHandler` struct, a helper used to move `FnMut` closures into C++. It holds a boxed closure and provides methods to create and access it.

```Rust
// A signal handler helper which is used to move a FnMut closure into C++
#[doc(hidden)]
#[repr(transparent)]
pub struct CxxQtSignalHandler<T>
where
    T: CxxQtSignalHandlerClosure,
{
    closure: Box<T::FnType>,
}

impl<T>
    CxxQtSignalHandler<T>
where
    T: CxxQtSignalHandlerClosure,
{
    /// Create a new signal handler with the given closure
    //
    // Note that we cannot use From as we cannot infer the type in the caller
    pub fn new(closure: Box<T::FnType>) -> Self {
        Self { closure }
    }

    /// A mutable reference to the inner closure
    pub fn closure(&mut self) -> &mut Box<T::FnType> {
        &mut self.closure
    }
}
```

--------------------------------

### Rust Method Signature: qt_thread

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/trait.Threading

Provides the signature for the `qt_thread` method required by the `Threading` trait. This method returns a `CxxQtThread` instance, which is used to queue closures for execution on the Qt event loop from a separate thread.

```Rust
fn qt_thread(&self) -> CxxQtThread<Self>
```

--------------------------------

### Queue Closure to Qt Event Loop (Rust)

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/struct.CxxQtThread

The `queue` method allows a closure to be executed on the Qt event loop associated with a QObject. The closure receives a pinned mutable reference to the QObject, enabling thread-safe updates. It returns a Result indicating success or a `ThreadingQueueError`.

```rust
pub fn queue<F>(&self, f: F) -> Result<(), ThreadingQueueError>
where
    F: FnOnce(Pin<&mut T>) + Send + 'static,

```

--------------------------------

### Default Implementation for QMetaObjectConnection in Rust

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/struct.QMetaObjectConnection

Implements the `Default` trait for QMetaObjectConnection, providing a default value for the struct. This is useful for initializing connections.

```rust
impl Default for QMetaObjectConnection {
    fn default() -> Self {
        // Implementation details
    }
}
```

--------------------------------

### CXX-Qt Threading Helper Struct (Rust)

Source: https://docs.rs/cxx-qt/0.7.2/src/cxx_qt/threading.rs

Represents a thread-safe helper for QObjects that implement the Threading trait. It allows queuing closures to the Qt event loop from background threads, ensuring thread-safe updates to the QObject. It implements Clone, Drop, Send, and Sync for robust multi-threaded usage.

```Rust
use core::{marker::PhantomData, mem::MaybeUninit, pin::Pin};
use cxx::ExternType;
use thiserror::Error;

use crate::Threading;

/// A threading helper which is created from a QObject that implements [Threading].
///
/// This allows for queueing closures onto the Qt event loop from a background thread
/// as [CxxQtThread] implements [Send].
///
/// When the Rust thread needs to update a value in the QObject it can then queue a closure to the thread.
/// This closure will be executed on the thread the QObject lives in while holding a lock on the Rust object.
/// Updating the QObject is then thread-safe.
///
/// See the [Threading] example for more information.
#[repr(C)]
pub struct CxxQtThread<T>
where
    T: Threading,
{
    // The layout is one std::shared_ptr, which is two pointers in size
    _space: MaybeUninit<[usize; 2]>,
    _value: PhantomData<T>,
}

// Safety:
//
// Static checks on the C++ side to ensure the size is the same.
unsafe impl<T> ExternType for CxxQtThread<T>
where
    T: ExternType + Threading,
{
    type Id = T::ThreadingTypeId;
    type Kind = cxx::kind::Trivial;
}

impl<T> Clone for CxxQtThread<T>
where
    T: Threading,
{
    fn clone(&self) -> Self {
        T::threading_clone(self)
    }
}

impl<T> Drop for CxxQtThread<T>
where
    T: Threading,
{
    fn drop(&mut self) {
        T::threading_drop(self);
    }
}

// CxxQtThread is safe to be sent across threads and handles
// locking and checks with the original QObject to prevent issues
unsafe impl<T> Send for CxxQtThread<T> where T: Threading {}

// CxxQtThread is safe to use as a reference in parallel from multiple
// places as it protects the queue call and the closure with mutexes
unsafe impl<T> Sync for CxxQtThread<T> where T: Threading {}

impl<T>
    CxxQtThread<T>
where
    T: Threading,
{
    /// Queue the given closure onto the Qt event loop for this QObject
    ///
    /// The first argument of the closure is a pinned mutable reference to the QObject.
    /// With this parameter, you can then update the QObject to reflect any state changes that have occured in the background thread.
    pub fn queue<F>(&self, f: F) -> Result<(), crate::ThreadingQueueError>
    where
        F: FnOnce(Pin<&mut T>),
        F: Send + 'static,
    {
        T::queue(self, f)
    }

    /// Checks whether the associated `QObject` has been destroyed.
    ///
    /// This method only confirms if the `QObject` has already been destroyed.
    /// It does not guarantee that the `QObject` remains alive for any
    /// subsequent operations. There is a potential race condition when using
    /// `is_destroyed()` before calling `queue`. Specifically, the `QObject` may
    /// be destroyed after the check but before the `queue` call.
    ///
    /// For example:
    /// ```rust,ignore
    /// if !thread.is_destroyed() {
    ///     thread.queue(/*...*/).unwrap();
    /// }
    /// ```
    /// In this scenario, the `QObject` might be destroyed between the
    /// `is_destroyed` check and the `queue` invocation, resulting in a panic.
    ///
    /// To handle such cases safely, it is recommended to call `queue(...).ok()`
    /// directly without checking `is_destroyed()`. This approach allows you to
    /// handle the potential failure gracefully without risking a panic.
    ///
    /// However, `is_destroyed()` can still be useful in scenarios where you
    /// need to control loops or perform cleanup operations based on the
    /// destruction status of the `QObject`. For instance:
    /// ```rust,ignore
    /// while !thread.is_destroyed() {
    ///     thread.queue(/*...*/).ok();
    /// }
    /// ```
    pub fn is_destroyed(&self) -> bool {
        T::is_destroyed(self)
    }
}
```

--------------------------------

### Define InitializeArguments Type for CXX-Qt

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/trait.Constructor

The `InitializeArguments` type specifies arguments for initializing a QObject within the `initialize()` function. These must also be CXX-compatible types.

```rust
type InitializeArguments

The arguments that should be used to initialize the QObject in the `initialize()` function. This must be a tuple of CXX compatible types.
```

--------------------------------

### Construct Rust Struct with CXX-Qt new()

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/trait.Constructor

The `new` function is used to construct the inner Rust struct of a CXX-Qt QObject. This is useful for structs that do not implement the `Default` trait.

```rust
fn new(arguments: Self::NewArguments) -> <Self as CxxQtType>::Rust

This function is called to construct the inner Rust struct of the CXX-Qt QObject. You can use this to construct Rust structs that do not provide a Default implementation.
```

--------------------------------

### Release QMetaObjectConnectionGuard in Rust

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/struct.QMetaObjectConnectionGuard

Provides a method to release the connection managed by QMetaObjectConnectionGuard without disconnecting it. This allows the connection to persist even after the guard is no longer held.

```rust
pub fn release(self) -> QMetaObjectConnection
```

--------------------------------

### Define C++ Types and Functions for QMetaObjectConnection in Rust

Source: https://docs.rs/cxx-qt/0.7.2/src/cxx_qt/connection.rs

This Rust code snippet uses the `cxx` crate to define a bridge to C++ types and functions. It declares C++ types like `QMetaObjectConnection` and functions for default construction, disconnection, and dropping connections, making them accessible from Rust. It also defines the `ConnectionType` enum with its variants.

```rust
use cxx::{type_id, ExternType};
use std::mem::MaybeUninit;

#[cxx::bridge]
mod ffi {
    #[namespace = "rust::cxxqt1"]
    unsafe extern "C++" {
        include!("cxx-qt/connection.h");

        #[doc(hidden)]
        type QMetaObjectConnection = crate::QMetaObjectConnection;

        #[doc(hidden)]
        #[rust_name = "qmetaobjectconnection_default"]
        fn qmetaobjectconnectionDefault() -> QMetaObjectConnection;

        #[doc(hidden)]
        #[rust_name = "qmetaobjectconnection_disconnect"]
        fn qmetaobjectconnectionDisconnect(connection: &QMetaObjectConnection) -> bool;

        #[doc(hidden)]
        #[rust_name = "qmetaobjectconnection_drop"]
        fn qmetaobjectconnectionDrop(connection: &mut QMetaObjectConnection);
    }

    /// This enum describes the types of connection that can be used with signals.
    ///
    /// Note that UniqueConnection is not supported.
    #[namespace = "Qt"]
    #[repr(i32)]
    enum ConnectionType {
        /// If the receiver lives in the thread that emits the signal, Qt::DirectConnection is used.
        /// Otherwise, Qt::QueuedConnection is used. The connection type is determined when the signal is emitted.
        AutoConnection,
        /// The slot is invoked immediately when the signal is emitted.
        /// The slot is executed in the signalling thread.
        DirectConnection,
        /// The slot is invoked when control returns to the event loop of the receiver's thread.
        /// The slot is executed in the receiver's thread.
        QueuedConnection,
        /// Same as Qt::QueuedConnection, except that the signalling thread blocks until the slot returns.
        /// This connection must not be used if the receiver lives in the signalling thread, or else the application will deadlock.
        BlockingQueuedConnection,
    }

    // We need to tell CXX that the type already exists, otherwise the following error ocucrs
    // "scoped/unscoped mismatch in enum"
    #[namespace = "Qt"]
    unsafe extern "C++" {
        type ConnectionType;
    }
}

/// Represents a handle to a signal-slot (or signal-functor) connection.
///
/// This struct is returned when a connection is made using `on_SIGNAL_NAME`.
///
/// Note that when this struct is dropped the connection is disconnected.
/// So so keep a connection active either hold onto the struct for the duration
/// that the connection should be active or call `release`.
#[repr(C)]
pub struct QMetaObjectConnection {
    _space: MaybeUninit<usize>,
}

impl Default for QMetaObjectConnection {
    fn default() -> Self {
        ffi::qmetaobjectconnection_default()
    }
}

impl Drop for QMetaObjectConnection {
    fn drop(&mut self) {
        ffi::qmetaobjectconnection_drop(self);
    }
}

impl QMetaObjectConnection {
    /// Disconnect the signal
    pub fn disconnect(&self) -> bool {
        ffi::qmetaobjectconnection_disconnect(self)
    }
}

// Safety:
//
// Static checks on the C++ side to ensure the size is the same.
unsafe impl ExternType for QMetaObjectConnection {
    type Id = type_id!("rust::cxxqt1::QMetaObjectConnection");
    type Kind = cxx::kind::Trivial;
}

pub use ffi::ConnectionType;

```

--------------------------------

### ConnectionType Enum

Source: https://docs.rs/cxx-qt/0.7.2/src/cxx_qt/connection.rs

Describes the types of connection that can be used with signals. Note that UniqueConnection is not supported.

```APIDOC
## Enum ConnectionType

### Description
This enum describes the types of connection that can be used with signals. Note that UniqueConnection is not supported.

### Values
- **AutoConnection**: If the receiver lives in the thread that emits the signal, Qt::DirectConnection is used. Otherwise, Qt::QueuedConnection is used. The connection type is determined when the signal is emitted.
- **DirectConnection**: The slot is invoked immediately when the signal is emitted. The slot is executed in the signalling thread.
- **QueuedConnection**: The slot is invoked when control returns to the event loop of the receiver's thread. The slot is executed in the receiver's thread.
- **BlockingQueuedConnection**: Same as Qt::QueuedConnection, except that the signalling thread blocks until the slot returns. This connection must not be used if the receiver lives in the signalling thread, or else the application will deadlock.
```

--------------------------------

### Implement ExternType for CxxQtSignalHandler

Source: https://docs.rs/cxx-qt/0.7.2/src/cxx_qt/signalhandler.rs

Implements the `ExternType` trait for `CxxQtSignalHandler`, enabling its use with C++. This implementation ensures static checks for size compatibility between C++ and Rust.

```Rust
// Safety:
//
// Static checks on the C++ and Rust side to ensure the size is the same.
unsafe impl<T> ExternType for CxxQtSignalHandler<T>
where
    T: CxxQtSignalHandlerClosure,
{
    type Kind = cxx::kind::Trivial;
    type Id = T::Id;
}
```

--------------------------------

### Drop Implementation for QMetaObjectConnection in Rust

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/struct.QMetaObjectConnection

Implements the `Drop` trait for QMetaObjectConnection. This ensures that the connection is automatically disconnected when the QMetaObjectConnection instance goes out of scope.

```rust
impl Drop for QMetaObjectConnection {
    fn drop(&mut self) {
        // Implementation details
    }
}
```

--------------------------------

### Define QMetaObjectConnectionGuard Struct in Rust

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/struct.QMetaObjectConnectionGuard

Defines the QMetaObjectConnectionGuard struct, which acts as a guard for signal-slot connections. When this struct is dropped, the connection is automatically disconnected. It can be created from a QMetaObjectConnection.

```rust
pub struct QMetaObjectConnectionGuard { /* private fields */ }
```

--------------------------------

### Immutable Rust Reference Method for CxxQtType

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/trait.CxxQtType

Defines the 'rust' method within the CxxQtType trait. This method returns an immutable reference to the Rust struct that backs the C++ object.

```rust
fn rust(&self) -> &Self::Rust;
// Retrieve an immutable reference to the Rust struct backing this C++ object
```

--------------------------------

### CxxQtThread<T>

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/struct.CxxQtThread

A threading helper that allows queueing closures onto the Qt event loop from a background thread. It ensures thread-safe updates to QObjects.

```APIDOC
## Struct CxxQtThread<T>

### Description
A threading helper which is created from a QObject that implements Threading. This allows for queueing closures onto the Qt event loop from a background thread as CxxQtThread implements Send. When the Rust thread needs to update a value in the QObject it can then queue a closure to the thread. This closure will be executed on the thread the QObject lives in while holding a lock on the Rust object. Updating the QObject is then thread-safe.

See the Threading example for more information.

### Fields

* `/* private fields */`

### Methods

#### `queue<F>(&self, f: F) -> Result<(), ThreadingQueueError>`

* **Description**: Queue the given closure onto the Qt event loop for this QObject. The first argument of the closure is a pinned mutable reference to the QObject. With this parameter, you can then update the QObject to reflect any state changes that have occured in the background thread.
* **Method**: `pub fn queue<F>`
* **Parameters**:
  * `f` (F): A closure that takes a `Pin<&mut T>` and is `Send + 'static`.
* **Returns**: `Result<(), ThreadingQueueError>` - Ok if the closure was queued successfully, Err otherwise.

#### `is_destroyed(&self) -> bool`

* **Description**: Checks whether the associated `QObject` has been destroyed. This method only confirms if the `QObject` has already been destroyed. It does not guarantee that the `QObject` remains alive for any subsequent operations. There is a potential race condition when using `is_destroyed()` before calling `queue`.
* **Method**: `pub fn is_destroyed`
* **Returns**: `bool` - True if the QObject is destroyed, false otherwise.

### Example Usage (Queueing Closure)

```rust
if !thread.is_destroyed() {
    thread.queue(|obj: Pin<&mut T>| {
        // Update the QObject here
    }).unwrap();
}
```

### Example Usage (Safe Queueing)

```rust
thread.queue(|obj: Pin<&mut T>| {
    // Update the QObject here
}).ok(); // Handles potential destruction gracefully
```

### Example Usage (Looping with Destruction Check)

```rust
while !thread.is_destroyed() {
    thread.queue(|obj: Pin<&mut T>| {
        // Perform operations
    }).ok();
}
```
```

--------------------------------

### Define QMetaObjectConnection Struct in Rust

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/struct.QMetaObjectConnection

Defines the QMetaObjectConnection struct, which represents a handle to a signal-slot connection. This struct is returned when a connection is made and is automatically disconnected when dropped.

```rust
#[repr(C)]
pub struct QMetaObjectConnection { /* private fields */ }
```

--------------------------------

### QMetaObjectConnection Struct

Source: https://docs.rs/cxx-qt/0.7.2/src/cxx_qt/connection.rs

Represents a handle to a signal-slot (or signal-functor) connection. This struct is returned when a connection is made using `on_SIGNAL_NAME`. When this struct is dropped, the connection is disconnected.

```APIDOC
## Struct QMetaObjectConnection

### Description
Represents a handle to a signal-slot (or signal-functor) connection. This struct is returned when a connection is made using `on_SIGNAL_NAME`. Note that when this struct is dropped the connection is disconnected. So to keep a connection active either hold onto the struct for the duration that the connection should be active or call `release`.

### Methods
#### `default()`
Creates a default `QMetaObjectConnection`.

- **Returns**: A default `QMetaObjectConnection`.

#### `drop()`
Disconnects the signal-slot connection when the `QMetaObjectConnection` is dropped.

#### `disconnect()`
Disconnects the signal.

- **Returns**: `true` if the signal was successfully disconnected, `false` otherwise.
```

--------------------------------

### Send Implementation for CxxQtThread (Rust)

Source: https://docs.rs/cxx-qt/0.7.2/cxx_qt/struct.CxxQtThread

Marks `CxxQtThread` as `Send`, indicating that it can be safely transferred between threads. This is a fundamental requirement for using the struct in multi-threaded Rust applications.

```rust
impl<T> Send for CxxQtThread<T>
where T: Threading,
{
}

```
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