Stateflow.Transition

Transition in chart, state, box, or function

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    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.

    example

    Input Arguments

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

    Properties

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    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

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

    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.

    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.

    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.

    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.

    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.

    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.

    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.

    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.

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

    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.

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

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

    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.

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

    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.

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

    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.

    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

    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

    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

    This property is read-only.

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

    This property is read-only.

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

    This property is read-only.

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

    Identification

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

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

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

    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.

    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

    getParentIdentify parent of object
    commentedByIdentify objects that implicitly comment out a graphical object
    dialogOpen properties dialog box
    viewDisplay object in editing environment
    highlightHighlight graphical object
    fitToViewZoom in on graphical object

    Examples

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

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

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

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

    Transition with a trigger, a condition, and a condition 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();'

    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];

    Stateflow chart with a default transition leading to a state.

    This example uses:

    Open Live Script

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

    A Stateflow chart with two junctions. One junction is inside a subchart, while the other is outside the subchart. The chart does not have transitions.

    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;
    Assertion failed:  Deviant 'root deviant' not opened for transactions.
Attempt to modify object of type 'StateflowDI.Junction' [id = -1 ]  at kernel/deviant/Deviant.cpp:70: 

    st.IsGrouped = false;

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

    A Stateflow subchart that has been converted to a state. The state contains a junction. Outside of the state, there is a disconnected junction.

    Add a transition that connects junction j1 to junction j2.

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

    A junction inside a state connects to an exterior junction by using a transition.

    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;

    Stateflow chart with a subchart. A supertransition connects a junction inside the subchart to a junction outside the subchart.

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

    Version History

    Introduced before R2006a

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    See Also

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    Topics