Context QML Type

Configures and initialises the ROS 2 context for a QML application. More...

• List of all members, including inherited members

Properties

• multithreaded : bool
• nodeArgs : list<string>
• threadCount : int

Detailed Description

Context provides a declarative way to initialise the underlying rclcpp context from QML, removing the need for a C++ entry point to call QRos2Context::init().

If no Context item is present, the first Node that is created will auto-initialise the context with default settings (no extra ROS args, and a threaded executor). Use Context when you need explicit control over these options. Or use the QRos2Context type from C++ for even more fine-grained controll.

import QtRos2.Core

Context {
    // Remap the joint_states topic for a namespaced robot:
    nodeArgs: ["--ros-args", "--remap", "/joint_states:=/my_robot/joint_states"]
    multithreaded: false
}

Place Context before any Node item in the same component so that the context is ready before nodes are created.

Property Documentation

multithreaded : bool

When true, a MultiThreadedExecutor is used instead of the default SingleThreadedExecutor. Defaults to true.

nodeArgs : list<string>

Additional command-line arguments forwarded to rclcpp::init(), e.g. ["--ros-args", "--remap", "/joint_states:=/robot/joint_states"]. Must be set before the component completes and can only be set once.

threadCount : int

Number of threads for the multi-threaded executor. 0 means hardware-concurrency. Ignored when multithreaded is false.