Class ListQuestion


  • public abstract class ListQuestion
    extends Question
    A question to support the construction of an open-ended set of complex values determined by a specified subinterview.

    A "loop" is created by creating an instance of a subtype of ListQuestion. The subtype must implement createBody() to create instances of the subinterview for the body of the loop. getNext() should return the next question after the loop has been completed.

    Computationally, this question behaves more like a "fork" than a "loop". Semantically, it is as though all the bodies are evaluated together, in parallel, rather than serially one after the other. In the GUI presentation, it is expected that only one body is displayed at a time, and that the user can choose which body is viewed. This avoids having all the loops unrolled all the time in the display of the current path. Internally, each ListQuestion has a sibling that is created automatically, and together, these two questions bracket the set of loop bodies.

    • Constructor Detail

      • ListQuestion

        protected ListQuestion​(Interview interview,
                               java.lang.String tag)
        Create a question with a nominated tag.
        Parameters:
        interview - The interview containing this question.
        tag - A unique tag to identify this specific question.
    • Method Detail

      • createBody

        public abstract ListQuestion.Body createBody​(int index)
        Create a new instance of a body for this loop question. The body is a subinterview that contains the questions for the body of the loop. The body does not become one of the set of bodies for the loop until the set is updated with setBodies(com.sun.interview.ListQuestion.Body[], int).
        Parameters:
        index - the position that this body will have within the set of bodies for the loop. This value should be passed through to the Body constructor.
        Returns:
        a new instance of a body for this loop question
      • isEnd

        public final boolean isEnd()
        Check if this is the question that appears at the beginning or at the end of the loop. When a ListQuestion is created, a sibling is automatically created that will appear at the end of the loop.
        Returns:
        false if this is the main question, that appears at the head of the loop, or true if this is the question that is automatically created to appear at the end of the lop.
      • getOther

        public ListQuestion getOther()
        Get the sibling question that appears at the other end of the loop. When a ListQuestion is created, a sibling is automatically created that will appear at the end of the loop. From either of these questions, you can use this method to get at the other one.
        Returns:
        the sibling question that appears at the other end of the loop
      • getSelectedBody

        public ListQuestion.Body getSelectedBody()
        Get the currently selected loop body, or null, as selected by by setValue.
        Returns:
        the currently selected loop body, or null, if none.
      • getValue

        public int getValue()
        Get the index of the currently selected loop body, or an out of range value (typically less than zero) if none is selected.
        Returns:
        the index of the currently selected loop body, or an out of range value (typically less than zero) if none is selected
        See Also:
        setValue(int)
      • getValueOnPath

        public int getValueOnPath()
                           throws Interview.NotOnPathFault
        Verify this question is on the current path, and if it is, return the current value.
        Returns:
        the current value of this question
        Throws:
        Interview.NotOnPathFault - if this question is not on the current path
        See Also:
        getValue()
      • getStringValue

        public java.lang.String getStringValue()
        Get a string representation of the index of the currently selected loop body, or an out of range value (typically less than zero) if none is selected.
        Specified by:
        getStringValue in class Question
        Returns:
        a string representing the current response to this question, or null.
        See Also:
        Question.setValue(String)
      • setValue

        public void setValue​(int newValue)
        Set the index of the loop body to be selected. If the value is out of range, no loop body will be selected.
        Parameters:
        newValue - the index of the loop body to be selected
        See Also:
        getValue()
      • setValue

        public void setValue​(java.lang.String s)
        Set the index of the loop body to be selected. If the value is out of range, no loop body will be selected.
        Specified by:
        setValue in class Question
        Parameters:
        s - a string containing the index of the loop body to be selected. If the string does not contain a valid integer, the value will be set to -1.
        See Also:
        getValue()
      • isValueValid

        public boolean isValueValid()
        Check if the question currently has a valid response. For a ListQuestion, this is normally true.
        Specified by:
        isValueValid in class Question
        Returns:
        true if the question currently has a valid response, and false otherwise.
      • isValueAlwaysValid

        public boolean isValueAlwaysValid()
        Check if the question always has a valid response. For a ListQuestion, this is normally false.
        Specified by:
        isValueAlwaysValid in class Question
        Returns:
        true if the question always has a valid response, and false otherwise.
      • clear

        public void clear()
        Remove all the bodies currently allocated for this question, and set the value of the question to indicate no loop body selected.
        Specified by:
        clear in class Question
      • getEndSummary

        public java.lang.String getEndSummary()
        Get the summary text for the end question. When a ListQuestion is created, a sibling is automatically created that will appear at the end of the loop. Override this method to override the default behavior to get the summary text from the standard resource bundle. The tag for the end question is the same as the tag for the main question, with ".end" appended.
        Returns:
        the summary text for the end question
        See Also:
        Question.getSummary(), getOther()
      • getEndText

        public java.lang.String getEndText()
        Get the question text for the end question. When a ListQuestion is created, a sibling is automatically created that will appear at the end of the loop. Override this method to override the default behavior to get the question text from the standard resource bundle. The tag for the end question is the same as the tag for the main question, with ".end" appended.
        Returns:
        the question text for the end question
        See Also:
        getEndTextArgs(), Question.getText(), getOther()
      • getEndTextArgs

        public java.lang.Object[] getEndTextArgs()
        Get the formatting arguments for the question text for the end question. When a ListQuestion is created, a sibling is automatically created that will appear at the end of the loop. Override this method to override the default behavior to return null.
        Returns:
        the formatting arguments for the question text for the end question
        See Also:
        getEndText(), Question.getTextArgs(), getOther()
      • load

        protected void load​(java.util.Map data)
        Description copied from class: Question
        Load any state for this question from a dictionary, using the tag as the key.
        Specified by:
        load in class Question
        Parameters:
        data - The map from which to load the value for this question.
      • save

        protected void save​(java.util.Map data)
        Description copied from class: Question
        Save any state for this question in a dictionary, using the tag as the key.
        Specified by:
        save in class Question
        Parameters:
        data - The map in which to save the value for this question.
      • getBodyCount

        public int getBodyCount()
        Get the number of bodies (iterations) currently allocated within the loop.
        Returns:
        the number of bodies currently allocated within the loop
      • getBody

        public ListQuestion.Body getBody​(int index)
        Get a specified body from the loop.
        Parameters:
        index - the position of the desired body within the set of bodies currently allocated within the loop.
        Returns:
        the specified body
        Throws:
        java.lang.ArrayIndexOutOfBoundsException - if index does not identify a valid body
      • setBodies

        public void setBodies​(ListQuestion.Body[] newBodies,
                              int newValue)
        Set the set of bodies allocated within the loop, and the index of one which should be selected. The bodies will normally come from a combination of the bodies returned from getBodies() or new ones created by createBody().
        Parameters:
        newBodies - the set of bodies to be taken as the new set of loop bodies
        newValue - the index of the body which should be the selected body.
        See Also:
        getBodies()
      • getIncompleteBodyCount

        public int getIncompleteBodyCount()
        Get the number of bodies for this loop that are currently incomplete, as determined by ListQuestion.Body.isBodyFinishable().
        Returns:
        the number of bodies for this loop that are currently incomplete.