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Class semper.preferences.PrefFieldChoice

java.lang.Object
   |
   +----semper.preferences.PrefField
           |
           +----semper.preferences.PrefFieldChoice

public class PrefFieldChoice

extends PrefField

Version:

$Revision: 1.10 $ $Date: 1997/01/21 14:56:37 $

Author:

Louis Salvail

See Also:

PrefFieldString, PrefFieldLabel, PrefFieldNegotiable, PrefFieldCheckBox

PrefFieldChoice()

Constructor called by newInstance when this object is internalized.

PrefFieldChoice(String, String)

Constructor for an empty choice with name and label with default constraints.

PrefFieldChoice(String, String, GridBagConstraints)

Constructor for an empty choice with label and name and specified constraints.

addChoice(String)

This allows to add a new string for the possible choices.

applyModification()

Apply the user change.

cancel()

Cancels the last user change.

getItem(int)

Returns the string at a given index encoded with an int.

getItem(Object)

Returns the string at a given index.

getLabel()

Returns the Label associated with this Choice.

getValue()

Returns the index of the currently selected item for that field.

isModified()

Tells if the value has been modified by the user.

isOK()

Returns always true because no constraints are associated with a choice field.

myStreamSize()

Returns the size of the stream that would hold the externalized form of this field.

readObject(StreamInputInterface)

Internalizes this choice field.

setValue(int)

This set the selected value with int argument.

setValue(Integer)

This set the selelected value with Integer argument.

setValue(Object)

This set the selected value for that field either by specifying the index or the string of the item.

showme(PrefFrame)

This adds the approriate choice to a frame.

writeObject(StreamOutputInterface)

Externalizes this choice field.

  public PrefFieldChoice(String fieldname,
                         String chLabel,
                         GridBagConstraints constraints) throws PreferencesException

Constructor for an empty choice with label and name and specified constraints.

Parameters:

fieldname - is the string by which this component is accessed through the preferences manager.

chLabel - is the string appearing at the right of the choice component.

constraints - is the set of GridBagConstraints for that component.

Returns:

the new object.

Throws: PreferencesException

when one of fieldname or chLabel is null.

See Also:

GridBagConstraints

  public PrefFieldChoice(String fieldname,
                         String chLabel) throws PreferencesException

Constructor for an empty choice with name and label with default constraints.

Parameters:

fieldname - is the string by which this component is accessed through the preferences manager.

chLabel - is the string appearing at the right of the choice component.

Returns:

the new empty object.

Throws: PreferencesException

when one of fieldname or chLabel is null.

See Also:

GridBagConstraints

  public PrefFieldChoice()

Constructor called by newInstance when this object is internalized. Otherwise, you should not use this constructor.

Returns:

the new empty object.

  public void addChoice(String item)

This allows to add a new string for the possible choices.

Parameters:

item - is the string describing this choice

Returns:

none.

  public void showme(PrefFrame p)

This adds the approriate choice to a frame.

Parameters:

p - is the frame where the object will be shown.

Returns:

none.

Overrides:

showme in class PrefField

  public Object getValue()

Returns the index of the currently selected item for that field.

Returns:

the index of the selected item with an Integer object. The first item is at index 0. The returned value is the last stored selected item.

Overrides:

getValue in class PrefField

  public String getItem(Object index)

Returns the string at a given index. The call getStringAt(getValue()) returned the string actually selected for that field.

Parameters:

index - is an object encoding an Integer representing the index to help the wrapping with getValue().

Returns:

the string located at the index of that field. If the object does not encode a correct index (meaning an appriopriate Integer) nulll is returned.

  public String getItem(int index)

Returns the string at a given index encoded with an int.

Parameters:

index - is the index of the string.

Returns:

the string lacated at the given index of that field. if the value of the index is out of range a null string is returned.

  public void setValue(Object newval)

This set the selected value for that field either by specifying the index or the string of the item.

Parameters:

newval - is an object encoding either an Integer encoding the index of the item to select or the string corresponding to the item to select. If the object does not encode an appropriate String or Integer then nothing is done.

Returns:

none.

Overrides:

setValue in class PrefField

  public void setValue(int newval)

This set the selected value with int argument.

Parameters:

newval - is the index of the selected item. Nothing is done if the index is not in the available range.

Returns:

none.

  public void setValue(Integer newval)

This set the selelected value with Integer argument.

Parameters:

newval - is the index of the new selected value.

Returns:

none.

  public boolean isModified()

Tells if the value has been modified by the user.

Returns:

true iff the new value selected by the user is different from the previous one.

Overrides:

isModified in class PrefField

  public boolean applyModification()

Apply the user change.

Returns:

true iff there was a change and it has been applied.

Overrides:

applyModification in class PrefField

  public boolean isOK()

Returns always true because no constraints are associated with a choice field.

Returns:

true.

Overrides:

isOK in class PrefField

  public void cancel()

Cancels the last user change.

Returns:

none.

Overrides:

cancel in class PrefField

  public String getLabel()

Returns the Label associated with this Choice.

Returns:

the label.

  public int myStreamSize() throws StreamIOException

Returns the size of the stream that would hold the externalized form of this field.

Returns:

the size of the stream in bytes

Overrides:

myStreamSize in class PrefField

See Also:

Streamable

  public void readObject(StreamInputInterface stream) throws StreamIOException

Internalizes this choice field.

Parameters:

stream - is the stream of data the object state is retrieved from

Returns:

none.

Overrides:

readObject in class PrefField

See Also:

Streamable

  public void writeObject(StreamOutputInterface stream) throws StreamIOException

Externalizes this choice field.

Parameters:

stream - is the stream of data the object state is recorded in

Returns:

none

Overrides:

writeObject in class PrefField

See Also:

Streamable

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