MultiArrayLayoutSubscriber QML Type

Subscribes to std_msgs::msg::MultiArrayLayout messages — This was originally provided as an example message. More...

This type is deprecated since QtRos2.StdMsgs Foxy. We strongly advise against using it in new code.

• List of all members, including inherited members

Properties

• dataOffset : uint32_t
• dim : list<multiArrayDimension>
• message : multiArrayLayout

Signals

• messageReceived(multiArrayLayout msg)

Detailed Description

It is recommended to create your own semantically meaningful message. However if you would like to continue using this please use the equivalent in example_msgs.

The multiarray declares a generic multi-dimensional array of a particular data type. Dimensions are ordered from outer most to inner most.

Accessors should ALWAYS be written in terms of dimension stride and specified outer-most dimension first.

multiarray(i,j,k) = data[data_offset + dim_stride[1]*i + dim_stride[2]*j + k]

A standard, 3-channel 640x480 image with interleaved color channels would be specified as:

dim[0].label = "height" dim[0].size = 480 dim[0].stride = 3*640*480 = 921600 (note dim[0] stride is just size of image) dim[1].label = "width" dim[1].size = 640 dim[1].stride = 3*640 = 1920 dim[2].label = "channel" dim[2].size = 3 dim[2].stride = 3

multiarray(i,j,k) refers to the ith row, jth column, and kth channel.

MultiArrayLayoutSubscriber receives multiArrayLayout values from a ROS 2 topic. Set the topic and node properties, then connect to the messageReceived() signal.

See also MultiArrayLayoutPublisher and multiArrayLayout.

Property Documentation

dataOffset : uint32_t

The dataOffset field of the last received message. Updated whenever a new message arrives. dataOffsetChanged is emitted on every update.

dim : list<multiArrayDimension>

The dim field of the last received message. Updated whenever a new message arrives. dimChanged is emitted on every update.

message : multiArrayLayout

The last message received on topic. Updated whenever a new message arrives.

Signal Documentation

messageReceived(multiArrayLayout msg)

Emitted when a new multiArrayLayout arrives on topic. msg contains the received value.