Provides tools for translate a BT in DOT and publishing it to ROS for visualization in RQT. More...

#include <dot_bt.h>

Public Member Functions
	DotBt (TreeNode *root, const std::string &topic="/bt_dotcode", double ros_rate=50, bool left_right=false, bool multiple_parents=false)
	The default constructor.
std::string	getDotFile ()
	Returns the current DOT code produced for the BT.
void	publish ()
	Publishes the tree for visualization.
	~DotBt ()
	An empty destructor.
Private Member Functions
std::string	defineNodeDot (TreeNode *node, const std::string &alias)
	Produces DOT code for the definition of the node.
std::string	getAlias (const std::string &name)
	Returns the alias of a node.
void	produceDot (TreeNode node, TreeNode parent=NULL, const std::string &parent_alias="")
	Produces DOT code for the tree recursively.
Private Attributes
std::vector< std::string >	aliases_
	Stores the aliases of each node of tree. It is used for avoiding conflicts due to nodes with the same name or multiple parents.
std::string	dot_file_
	Stores the DOT code of the current tree.
ros::Publisher	dotbt_publisher_
	A ROS publisher for publishing DotBt::dot_file_.
bool	left_right_
	True for left to right visualization. False for top to down.
ros::Rate	loop_rate_
	The rate at which the DotBt::dotbt_publisher_ will publish the tree.
int	multiple_alias_solver_
bool	multiple_parents_
	True if you want to visualize nodes with multiple parents without duplication.
ros::NodeHandle	n_
	A node handle used by the ROS publisher DotBt::dotbt_publisher_.
TreeNode *	root_
	The root of the Behavior Tree.
std::string	topic_
	Stores the name of the topic that DotBt::dotbt_publisher_ will publish.

Detailed Description

Provides tools for translate a BT in DOT and publishing it to ROS for visualization in RQT.

The class generates code of the DOT graph description language which describes the current BT running. It also provide ROS publisher for publishing this code in a ROS topic. Then, the user can use the rqt_dot plugin in order to visualize in real-time the current tree and the status of each node. Regarding multi-parenting this class by default visualize the node multiple times under its different parents, in order to have a straight-forward visualization. Notice that in the implementation level the same node will be ticked. The class also provides the option to visualize the nodes with the same name as one node and the nodes with multiple parents as without replication (in order to detect visually these undesired replications).

Find below an example of use:

 {.cpp}
 #include <dot_bt.h>
 #include <thread>

 // ...

 // Assume root is a pointer TreeNode* to the root of your tree
 std::string topic = "/my_topic" // The ROS topic to publish the tree
 double rate = 50; // The rate of publishing in Hz
 BT::DotBt dot_bt(root, topic, rate);  // Call the constructor
 std::thread t(&BT::DotBt::publish, dot_bt); // A separate thread publishes the tree

Definition at line 63 of file dot_bt.h.

Constructor & Destructor Documentation

BT::DotBt::DotBt	(	TreeNode *	root,
		const std::string &	topic = `"/bt_dotcode"`,
		double	ros_rate = `50`,
		bool	left_right = `false`,
		bool	multiple_parents = `false`
	)		`[explicit]`

The default constructor.

Parameters:

root	A pointer to the root of the tree.
topic	The name of the ROS topic to publish the tree. Defaults to "/bt_dotcode".
ros_rate	The rate of the publishing in Hz. Defaults to 50Hz.
left_right	Set true if a left to right visualization is desired. Defaults to true, i.e. top-down visualization
multiple_parents	Set true if it is desired to visualize nodes with multiple parents (or nodes with the same name) without duplication. It is recommended to use the default (false) value for better results.

Definition at line 29 of file dot_bt.cpp.

BT::DotBt::~DotBt ( )

An empty destructor.

Definition at line 42 of file dot_bt.cpp.

Member Function Documentation

std::string BT::DotBt::defineNodeDot	(	TreeNode *	node,
		const std::string &	alias
	)		`[private]`

Produces DOT code for the definition of the node.

The current node's alias is used as the DOT object of the node. Then checks the type of the node (Action, Sequence etc) and gives the node the correct shape and label. Finally it checks the status of the node (Running, Idle, Failed etc) in order to give the correct color to each node.

Parameters:

node	A pointer to the node to be defined.
alias	The alias of the given node.

Returns:: The definition of the Node in DOT

Definition at line 44 of file dot_bt.cpp.

std::string BT::DotBt::getAlias ( const std::string & name ) [private]

Returns the alias of a node.

In general tranforms a string to lower case and replace the space with underscores. E.g. the string "My String" will be returned as "my_string".

Parameters:

name	The initial string as input

Returns:: The final string as output.

Definition at line 182 of file dot_bt.cpp.

std::string BT::DotBt::getDotFile ( )

Returns the current DOT code produced for the BT.

Returns:: The current DOT code

Definition at line 206 of file dot_bt.cpp.

void BT::DotBt::produceDot	(	TreeNode *	node,
		TreeNode *	parent = `NULL`,
		const std::string &	parent_alias = `""`
	)		`[private]`

Produces DOT code for the tree recursively.

Initially defines the current node calling DotBt::produceDot and then if the current node has a parent produces the DOT code for adding this node as the child of its parent. If the node has children repeats this process recursively. It also checks if the produced alias of the node is already existing in order to visualize with a different instance nodes with multiple parents or nodes with the same name.

Parameters:

node	The current node.
parent	The parent of the current node. Defaults to NULL for the root of the tree.
parent_alias	The alias of the parent to be used in the DOT code. Defaults to empty string in case this node is the root of the tree.

Definition at line 105 of file dot_bt.cpp.

void BT::DotBt::publish ( )

Publishes the tree for visualization.

This is the main API of the class. It publishes in the given topic with the given name the produced DOT code for the current BT running. Run it in a separate thread in your BT application.

Definition at line 211 of file dot_bt.cpp.