Stateflow.Transition

Transition in chart, state, box, or function

Description

Use Stateflow.Transition objects to create transitions from one operating mode to another. For more information, see Transition Between Operating Modes.

Creation

Syntax

transition = Stateflow.Transition(parent)

Description

transition = Stateflow.Transition(parent) creates a Stateflow.Transition object in a parent chart, state, box, or graphical function.

Input Arguments

parent — Parent for new transition

Stateflow.Chart object | Stateflow.State object | Stateflow.Box object | Stateflow.Function object

Parent for the new transition, specified as a Stateflow^® API object of one of these types:

• Stateflow.Box

• Stateflow.Chart

• Stateflow.Function

• Stateflow.State

Properties

Stateflow API objects have properties that correspond to the values you set in the Stateflow Editor. To access or modify a property, use dot notation. To access or modify multiple properties for multiple API objects, use the get and set functions, respectively. For more information, see Modify Properties and Call Functions of Stateflow Objects.

Content

LabelString — Label for transition

"" (default) | string scalar | character vector

Label for the transition, specified as a string scalar or character vector. For more information, see Specify Labels in States and Transitions Programmatically.

Condition — Transition condition

character vector

This property is read-only.

Transition condition, specified as a character vector. The value of this property depends on the LabelString property for the transition. For more information, see Specify Labels in States and Transitions Programmatically.

ConditionAction — Transition condition action

character vector

This property is read-only.

Transition condition action, specified as a character vector. The value of this property depends on the LabelString property for the transition. For more information, see Specify Labels in States and Transitions Programmatically.

TransitionAction — Transition action

character vector

This property is read-only.

Transition action, specified as a character vector. The value of this property depends on the LabelString property for the transition. For more information, see Specify Labels in States and Transitions Programmatically.

Trigger — Transition trigger

character vector

This property is read-only.

Transition trigger, specified as a character vector. The value of this property depends on the LabelString property for the transition. For more information, see Specify Labels in States and Transitions Programmatically.

ExecutionOrder — Execution order for transition

scalar

Execution order for the transition when its source is active, specified as an integer scalar. This property applies only when the UserSpecifiedStateTransitionExecutionOrder property of the chart that contains the transition is true. For more information, see Transition Evaluation Order.

IsExplicitlyCommented — Whether to comment out transition

false or 0 (default) | true or 1

Whether to comment out the transition, specified as a numeric or logical 1 (true) or 0 (false). Setting this property to true is equivalent to right-clicking the transition and selecting Comment Out. For more information, see Comment Out Objects in a Stateflow Chart.

IsImplicitlyCommented — Whether transition is implicitly commented out

true or 1 | false or 0

This property is read-only.

Whether the transition is implicitly commented out, specified as a numeric or logical 1 (true) or 0 (false). The transition is implicitly commented out when you explicitly comment out an object that contains it or when you comment out its source or destination. If the transition is contained in an atomic subchart or an atomic box, this property is false unless the explicitly commented object is also contained in the atomic subchart or atomic box.

IsCommented — Whether transition is commented out

true or 1 | false or 0

Since R2023a

This property is read-only.

Whether the transition is commented out, specified as a numeric or logical 1 (true) or 0 (false). This property is true when either IsExplicitlyCommented or IsImplicitlyCommented is true.

CommentText — Comment text

"" (default) | string scalar | character vector

Comment text added to the transition, specified as a string scalar or character vector. This property applies only when the IsExplicitlyCommented property is true. In the Stateflow Editor, when you point to the comment badge on the transition, the text appears as a tooltip. When you set the IsExplicitlyCommented property to false, the value of CommentText reverts to "".

Graphical Appearance

Source — Source of transition

[] (default) | Stateflow.AtomicSubchart object | Stateflow.Junction object | Stateflow.SimulinkBasedState object | Stateflow.State object

Source of the transition, specified as an empty array or a Stateflow API object of one of these types:

• Stateflow.AtomicSubchart

• Stateflow.Junction

• Stateflow.SimulinkBasedState

• Stateflow.State

SourceEndpoint — Position of transition endpoint at source

[2 2] (default) | [x y]

Position of the transition endpoint at its source, specified as a two-element numeric vector [x y] of coordinates relative to the upper left corner of the chart.

SourceOClock — Location of transition endpoint at source

0 (default) | scalar between 0 and 12

Location of the transition endpoint at its source, specified as a scalar between 0 and 12 that describes a clock position.

Destination — Destination of transition

[] (default) | Stateflow.AtomicSubchart object | Stateflow.Junction object | Stateflow.SimulinkBasedState object | Stateflow.State object

Destination of the transition, specified as an empty array or a Stateflow API object of one of these types:

• Stateflow.AtomicSubchart

• Stateflow.Junction

• Stateflow.SimulinkBasedState

• Stateflow.State

DestinationEndPoint — Position of transition endpoint at destination

[40 40] (default) | [x y]

Position of the transition endpoint at its destination, specified as a two-element numeric vector [x y] of coordinates relative to the upper left corner of the chart.

DestinationOClock — Location of transition endpoint at destination

0 (default) | scalar between 0 and 12

Location of the transition endpoint at its destination, specified as a scalar between 0 and 12 that describes a clock position.

MidPoint — Position of midpoint of transition

[21 21] (default) | [x y]

Position of the midpoint of the transition, specified as a two-element numeric vector [x y] of coordinates relative to the upper left corner of the chart.

LabelPosition — Position and size of transition label

[0 0 8 14] (default) | [left top width height]

Position and size of the transition label, specified as a four-element numeric vector of the form [left top width height].

ArrowSize — Size of transition arrow

scalar

Size of the transition arrow at the destination, specified as a scalar. When you change the destination of the transition, this property resets to the value of the ArrowSize property of the new destination.

FontSize — Font size for transition label

scalar

Font size for the transition label, specified as a scalar. The TransitionFont.Size property of the chart that contains the transition sets the initial value of this property.

Debugging

Debug — Debugger properties

Stateflow.TransDebug object

Debugger properties for the transition, specified as a Stateflow.TransDebug object with these properties:

• Breakpoints.WhenTested — Whether to set the When Transition is Tested breakpoint, specified as a numeric or logical 1 (true) or 0 (false).

• Breakpoints.WhenValid — Whether to set the When Transition is Valid breakpoint, specified as a numeric or logical 1 (true) or 0 (false).

For more information, see Set Breakpoints to Debug Charts.

Example: transition.Debug.Breakpoints.WhenTested = true;

Example: transition.Debug.Breakpoints.WhenValid = true;

Code Generation

IsVariant — Whether transition is a variant transition

false or 0 (default) | true or 1

Whether the transition is a variant transition, specified as a numeric or logical 1 (true) or 0 (false). For more information, see Control Indicator Lamp Dimmer Using Variant Conditions.

Hierarchy

Chart — Chart that contains transition

Stateflow.Chart object

This property is read-only.

Chart that contains the transition, specified as a Stateflow.Chart object.

Subviewer — Subviewer for transition

Stateflow.Chart object | Stateflow.State object | Stateflow.Box object | Stateflow.Function object

This property is read-only.

Subviewer for the transition, specified as a Stateflow.Chart, Stateflow.State, Stateflow.Box, or Stateflow.Function object. The subviewer is the chart or subchart where you can graphically view the transition.

Machine — Machine that contains transition

Stateflow.Machine object

This property is read-only.

Machine that contains the transition, specified as a Stateflow.Machine object.

Path — Location of parent in model hierarchy

character vector

This property is read-only.

Location of the parent of the transition in the model hierarchy, specified as a character vector.

Identification

Description — Description

"" (default) | string scalar | character vector

Description for the transition, specified as a string scalar or character vector.

Document — Document link

"" (default) | string scalar | character vector

Document link for the transition, specified as a string scalar or character vector.

Tag — User-defined tag

[] (default) | any data type

User-defined tag for the transition, specified as data of any type.

SSIdNumber — Session-independent identifier

scalar

This property is read-only.

Session-independent identifier, specified as an integer scalar. Use this property to distinguish the transition from other objects in its parent chart.

Id — Unique identifier

scalar

This property is read-only.

Unique identifier, specified as an integer scalar. Unlike SSIdNumber, the value of this property is reassigned every time you start a new MATLAB^® session and may be recycled after an object is deleted.

Object Functions

getParent	Identify parent of object
commentedBy	Identify objects that implicitly comment out a graphical object
dialog	Open properties dialog box
view	Display object in editing environment
highlight	Highlight graphical object
fitToView	Zoom in on graphical object

Examples

Add Transition to Chart

Add a transition that connects state s1 to state s2 in the chart ch.

transition = Stateflow.Transition(ch);
transition.Source = s1;
transition.Destination = s2;

Label Transitions

Add a label that specifies a trigger, condition, and condition action on the transition transition.

transition.LabelString = "trigger[guard]{action();}";

To extract the trigger, condition, and condition action specified by the transition label, enter:

trigger = transition.Trigger

trigger =

    'trigger'

condition = transition.Condition

condition =

    'guard'

action = transition.ConditionAction

action =

    'action();'

Add a Default Transition

Create a Stateflow.Transition object in the Stateflow.Chart object ch.

dt = Stateflow.Transition(ch);

Set the destination of the transition to the Stateflow.State object st.

dt.Destination = st;
dt.DestinationOClock = 0;

Place the source endpoint for the transition 30 pixels above the destination endpoint. Place the midpoint for the transition 15 pixels above the destination endpoint.

dt.SourceEndPoint = dt.DestinationEndPoint-[0 30];
dt.MidPoint = dt.DestinationEndPoint-[0 15];

Add Supertransition from Subchart

Create a supertransition that connects a junction inside a subchart to a junction outside the subchart.

Open the model and access the Stateflow.Chart object for the chart.

open_system("sfSupertransitionAPIExample")
ch = find(sfroot,"-isa","Stateflow.Chart");

Access the Stateflow.State object for the subchart and the Stateflow.Junction objects for the junctions.

st = find(ch,"-isa","Stateflow.State");
j1 = find(st,"-isa","Stateflow.Junction");
j2 = find(ch,"-isa","Stateflow.Junction","-depth",1);

Save the original position of the subchart to a temporary workspace variable subchartPosition.

subchartPosition = st.Position;

Convert the subchart to a normal state by setting its IsSubchart and IsGrouped properties to false.

st.IsSubchart = false;
st.IsGrouped = false;

When you convert a subchart to a normal state, it may change size to display its contents.

Add a transition that connects junction j1 to junction j2.

tr = Stateflow.Transition(ch);
tr.Source = j1;
tr.Destination = j2;

Revert the state to a subchart by setting its IsSubchart property to true. Restore the subchart to its original position.

st.IsSubchart = true;
st.Position = subchartPosition;

The transition between the junctions is now a supertransition that crosses the boundary of the subchart.

Version History

Introduced before R2006a

R2023a: New object function and property

Use the object function commentedBy and the property IsCommentedto investigate commented-out transitions:

• The object function commentedBy identifies the explicitly commented objects that cause a transition to be commented out.

• The property IsCommented indicates whether a transition is commented out. This property replaces the object function isCommented.