Time

To preserve the accuracy and allow for compatible serialization of message objects, anonymous wrappers for Time and Duration were introduced. These wrapper types are used for time and duration fields in received messages and the current time can be obtained using the Ros2.now() method of the Ros2 Singleton.

Example:

property var currentTime: Ros2.now()

Both wrapper types can be converted to QML/JavaScript Date objects using the toJSDate() method at the cost of micro- and nanosecond accuracy.

Please note that due to limitations in QML and JavaScript mathematical operations for Time and Duration are not possible.

API

class Time

Represents a point in time for a time source.

Please note that this is a Q_GADGET and not a QObject which means there is no signal emitted when properties change.

Public Functions

inline double seconds() const: Get the seconds since epoch as floating point including sub-seconds.

inline qint64 nanoseconds() const: Get the nanoseconds since epoch.

inline bool isZero() const: Whether the time represented by this instance is zero.

inline QDateTime toJSDate() const: A JS Date representing the value stored in this instance. Since JS Dates only have millisecond accuracy, information about microseconds and nanoseconds are lost. The time is always rounded down to prevent the JS Date from being in the future.

inline quint32 clockType() const: The type of the time source. See Ros2ClockTypes.

Properties

qint32 sec: The time in seconds (since 1970) as an integer. Use seconds() for floating point value including sub-seconds.

quint32 nanosec: The time in nanoseconds relative to the current second (as unsigned integer). Use nanoseconds() for the full time in nanoseconds since epoch.

class Duration

Represents a duration for a time source.

Please note that this is a Q_GADGET and not a QObject which means there is no signal emitted when properties change.

Public Functions

inline double seconds() const: Get the seconds of the duration as floating point including sub-seconds.

inline qint64 nanoseconds() const: Get the full duration as nanosecond.

inline bool isZero() const: Whether the duration represented by this instance is zero.

inline double toJSDuration() const: A JS duration representing the value stored in this instance. JS measures differences between two Dates as a (floating point) number of milliseconds.

Properties

qint32 sec: The duration in seconds as an integer. Use seconds() for floating point value including sub-seconds.

quint32 nanosec: The time in nanoseconds relative to the current second (as unsigned integer). Use nanoseconds() for the full duration in nanoseconds.

enum qml_ros2_plugin::ros_clock_types::Ros2ClockTypes

Values:

enumerator Uninitialized: Uninitialized.

enumerator Ros: ROS time.

enumerator System: System time.

enumerator Steady: Steady clock time.