acm.gui
Class DoubleField

java.lang.Object
  java.awt.Component
      java.awt.Container
          javax.swing.JComponent
              javax.swing.text.JTextComponent
                  javax.swing.JTextField
                      acm.gui.DoubleField

public class DoubleField
extends JTextField

This class implements a simple interactor that accepts a floating-point value.

Field Summary

Constructor Summary

DoubleField()

DoubleField(double value)

DoubleField(double low, double high)

DoubleField(double value, double low, double high)

Method Summary

boolean	getExceptionOnError() Returns the state of the error-handling flag.
String	getFormat() Returns the format currently in use for this field, or null if no format has been set.
double	getValue() Returns the value of this field as a double.
void	setExceptionOnError(boolean flag) Sets the error-handling mode of this interactor as specified by the flag parameter.
void	setFormat(String format) Sets the format used for the field.
void	setValue(double d) Sets the value of a field.

Constructor Detail

public DoubleField()

Creates a new field object for entering a double value. The contents of the field are initially blank.

Usage:

DoubleField field = new DoubleField();

public DoubleField(double value)

Creates a new field object for entering a double value. The contents of the field initially contain the specified value.

Usage:

DoubleField field = new DoubleField(value);

Parameter:

value

The value to store in the field

public DoubleField(double low, double high)

Creates a new field object for entering a double value, which is constrained to be within the specified range. The contents of the field are initially blank.

Usage:

DoubleField field = new DoubleField(low, high);

Parameters:

low	The lowest value in the permitted range
high	The highest value in the permitted range

public DoubleField(double value, double low, double high)

Creates a new field object for entering a double value, which is constrained to be within the specified range. The contents of the field initially contain the specified value.

Usage:

DoubleField field = new DoubleField(value, low, high);

Parameters:

value	The value to store in the field
low	The lowest value in the permitted range
high	The highest value in the permitted range

Method Detail

public boolean getExceptionOnError()

Returns the state of the error-handling flag.

Usage:	boolean flag = console.getExceptionOnError();
Returns:	The current setting of the error-handling mode (false to retry on errors; true to raise an exception)

public String getFormat()

Returns the format currently in use for this field, or null if no format has been set.

Usage:	String format = field.getFormat();
Returns:	The format for this field

public double getValue()

Returns the value of this field as a double. If this value is either not a legal numeric value or is outside the specified range, this method will either pop up a dialog allowing the user to reenter the value or throw an ErrorException depending on the state of the exceptionOnError flag.

Usage:	double d = field.getValue();
Returns:	The value stored in the field as a double

public void setExceptionOnError(boolean flag)

Sets the error-handling mode of this interactor as specified by the flag parameter. If flag is false (which is the default), calling getValue on this interactor displays a dialog that gives the user a chance to retry after erroneous input. If this value is set to true, illegal input raises an ErrorException instead.

Usage:

field.setExceptionOnError(flag);

Parameter:

flag	false to retry on errors; true to raise an exception

public void setFormat(String format)

Sets the format used for the field. The structure of the format string is described in the comments for the DecimalFormat class. If a format is set for the field, the format will also be used to read the number to ensure that localization is correctly handled.

Usage:

field.setFormat(format);

Parameter:

format

The format to use for the field

public void setValue(double d)

Sets the value of a field.

Usage:

field.setValue(d);

Parameter:

d	The value to be stored in the field