Package ptolemy.kernel.util

Class Location

  • All Implemented Interfaces:
    java.lang.Cloneable, Changeable, Debuggable, DebugListener, Derivable, Locatable, ModelErrorHandler, MoMLExportable, Moveable, Nameable, Settable, Singleton
    Direct Known Subclasses:
    RelativeLocation, Vertex
    public class Location
extends SingletonAttribute
implements Locatable
    An attribute that represents the center location of a node in a schematic.

    By default, an instance of this class is not visible in a user interface. This is indicated to the user interface by returning NONE to the getVisibility() method. The location is specified by calling setExpression() with a string that has the form "x,y" or "[x,y]" or "{x,y}", where x and y can be parsed into doubles.

    The default location is a two dimensional location with value {0.0, 0.0}. This class can also handle locations with greater than two dimensions.

    Since:
    Ptolemy II 2.1
    Version:
    $Id$
    Author:
    Steve Neuendorffer and Edward A. Lee
    Pt.AcceptedRating:
    Green (cxh)
    Pt.ProposedRating:
    Green (cxh)

    • Constructor Detail

      • Location

        public Location​(Workspace workspace)
        Construct an attribute in the specified workspace with an empty string as a name. If the workspace argument is null, then use the default workspace. The object is added to the directory of the workspace. Increment the version number of the workspace.
        Parameters:
        workspace - The workspace that will list the attribute.

    • Method Detail

      • addValueListener

        public void addValueListener​(ValueListener listener)
        Add a listener to be notified when the value of this attribute changes. If the listener is already on the list of listeners, then do nothing.
        Specified by:
        addValueListener in interface Settable
        Parameters:
        listener - The listener to add.
        See Also:
        removeValueListener(ValueListener)

      • clone

        public java.lang.Object clone​(Workspace workspace)
                       throws java.lang.CloneNotSupportedException
        Clone the location into the specified workspace. The new object is not added to the directory of that workspace (you must do this yourself if you want it there).
        Overrides:
        clone in class Attribute
        Parameters:
        workspace - The workspace for the cloned object.
        Returns:
        A new Location.
        Throws:
        java.lang.CloneNotSupportedException - If the base class throws it.
        See Also:
        NamedObj.exportMoML(Writer, int, String), NamedObj.setDeferringChangeRequests(boolean)

      • exportMoML

        public void exportMoML​(java.io.Writer output,
                       int depth,
                       java.lang.String name)
                throws java.io.IOException
        Write a MoML description of this object. MoML is an XML modeling markup language. In this class, the object is identified by the "property" element, with "name", "class", and "value" (XML) attributes. The body of the element, between the "<property>" and "</property>", is written using the _exportMoMLContents() protected method, so that derived classes can override that method alone to alter only how the contents of this object are described. The text that is written is indented according to the specified depth, with each line (including the last one) terminated with a newline. If this object is non-persistent, then nothing is written.
        Specified by:
        exportMoML in interface MoMLExportable
        Overrides:
        exportMoML in class NamedObj
        Parameters:
        output - The output writer to write to.
        depth - The depth in the hierarchy, to determine indenting.
        name - The name to use instead of the current name.
        Throws:
        java.io.IOException - If an I/O error occurs.
        See Also:
        NamedObj.isPersistent()

      • getDefaultExpression

        public java.lang.String getDefaultExpression()
        Return the default value of this Settable, if there is one. If this is a derived object, then the default is the value of the object from which this is derived (the "prototype"). If this is not a derived object, then the default is the first value set using setExpression(), or null if setExpression() has not been called.
        Specified by:
        getDefaultExpression in interface Settable
        Returns:
        The default value of this attribute, or null if there is none.
        See Also:
        setExpression(String)

      • getExpression

        public java.lang.String getExpression()
        Get the value that has been set by setExpression() or by setLocation(), whichever was most recently called, or return an empty string if neither has been called.

        If setExpression(String value) was called, then the return value is exactly what ever was passed in as the argument to setExpression. This means that there is no guarantee that the return value of getExpression() is a well formed Ptolemy array expression.

        If setLocation(double[] location) was called, then the return value is a well formed Ptolemy array expression that starts with "{" and ends with "}", for example "{0.0, 0.0}"

        Specified by:
        getExpression in interface Settable
        Returns:
        The expression.
        See Also:
        setExpression(String)

      • getLocation

        public double[] getLocation()
        Get the center location in some cartesian coordinate system.
        Specified by:
        getLocation in interface Locatable
        Returns:
        The location.
        See Also:
        setLocation(double[])

      • getValueAsString

        public java.lang.String getValueAsString()
        Get the value of the attribute, which is the evaluated expression.
        Specified by:
        getValueAsString in interface Settable
        Returns:
        The same as getExpression().
        See Also:
        getExpression()

      • removeValueListener

        public void removeValueListener​(ValueListener listener)
        Remove a listener from the list of listeners that is notified when the value of this variable changes. If no such listener exists, do nothing.
        Specified by:
        removeValueListener in interface Settable
        Parameters:
        listener - The listener to remove.
        See Also:
        addValueListener(ValueListener)

      • setExpression

        public void setExpression​(java.lang.String expression)
        Set the value of the attribute by giving some expression. This expression is not parsed until validate() is called, and the container and value listeners are not notified until validate() is called. See the class comment for a description of the format.
        Specified by:
        setExpression in interface Settable
        Parameters:
        expression - The value of the attribute.
        See Also:
        getExpression()

      • setLocation

        public void setLocation​(double[] location)
                 throws IllegalActionException
        Set the center location in some cartesian coordinate system, and notify the container and any value listeners of the new location. Setting the location involves maintaining a local copy of the passed parameter. No notification is done if the location is the same as before. This method propagates the value to any derived objects.
        Specified by:
        setLocation in interface Locatable
        Parameters:
        location - The location.
        Throws:
        IllegalActionException - If throw when attributeChanged() is called.
        See Also:
        getLocation()

      • setVisibility

        public void setVisibility​(Settable.Visibility visibility)
        Set the visibility of this attribute. The argument should be one of the public static instances in Settable.
        Specified by:
        setVisibility in interface Settable
        Parameters:
        visibility - The visibility of this attribute.
        See Also:
        getVisibility()

      • toString

        public java.lang.String toString()
        Get a description of the class, which is the class name and the location in parentheses.
        Overrides:
        toString in class NamedObj
        Returns:
        A string describing the object.

      • validate

        public java.util.Collection validate()
                              throws IllegalActionException
        Parse the location specification given by setExpression(), if there has been one, and otherwise set the location to 0.0, 0.0. Notify the container and any value listeners of the new location, if it has changed. See the class comment for a description of the format.
        Specified by:
        validate in interface Settable
        Returns:
        Null, indicating that no other instances of Settable are validated.
        Throws:
        IllegalActionException - If the expression is invalid.

      • _propagateValue

        protected void _propagateValue​(NamedObj destination)
                        throws IllegalActionException
        Propagate the value of this object to the specified object. The specified object is required to be an instance of the same class as this one, or a ClassCastException will be thrown.
        Overrides:
        _propagateValue in class NamedObj
        Parameters:
        destination - Object to which to propagate the value.
        Throws:
        IllegalActionException - If the value cannot be propagated.