Interface PropertyEditor

public interface PropertyEditor

A PropertyEditor class provides support for GUIs that want to allow users to edit a property value of a given type.

PropertyEditor supports a variety of different kinds of ways of displaying and updating property values. Most PropertyEditors will only need to support a subset of the different options available in this API.

Simple PropertyEditors may only support the getAsText and setAsText methods and need not support (say) paintValue or getCustomEditor. More complex types may be unable to support getAsText and setAsText but will instead support paintValue and getCustomEditor.

Every propertyEditor must support one or more of the three simple display styles. Thus it can either (1) support isPaintable or (2) both return a non-null String[] from getTags() and return a non-null value from getAsText or (3) simply return a non-null String from getAsText().

Every property editor must support a call on setValue when the argument object is of the type for which this is the corresponding propertyEditor. In addition, each property editor must either support a custom editor, or support setAsText.

Each PropertyEditor should have a null constructor.

Methods

setValue

void setValue(Object value)

Set (or change) the object that is to be edited. Primitive types such as "int" must be wrapped as the corresponding object type such as "java.lang.Integer".

Parameters:

value - The new target object to be edited. Note that this object should not be modified by the PropertyEditor, rather the PropertyEditor should create a new object to hold any modified value.

getValue

Object getValue()

Gets the property value.

Returns:

The value of the property. Primitive types such as "int" will be wrapped as the corresponding object type such as "java.lang.Integer".

isPaintable

boolean isPaintable()

Determines whether this property editor is paintable.

Returns:

True if the class will honor the paintValue method.

paintValue

void paintValue(Graphics gfx,
                Rectangle box)

Parameters:

gfx - Graphics object to paint into.

box - Rectangle within graphics object into which we should paint.

getJavaInitializationString

String getJavaInitializationString()

Returns:

a fragment of Java code representing an initializer for the current value. It should not contain a semi-colon (';') to end the expression.

getAsText

String getAsText()

Gets the property value as text.

Returns:

The property value as a human editable string.

Returns null if the value can't be expressed as an editable string.

If a non-null value is returned, then the PropertyEditor should be prepared to parse that string back in setAsText().

setAsText

void setAsText(String text)
        throws IllegalArgumentException

Set the property value by parsing a given String. May raise java.lang.IllegalArgumentException if either the String is badly formatted or if this kind of property can't be expressed as text.

Parameters:

text - The string to be parsed.

Throws:

IllegalArgumentException

getTags

String[] getTags()

If the property value must be one of a set of known tagged values, then this method should return an array of the tags. This can be used to represent (for example) enum values. If a PropertyEditor supports tags, then it should support the use of setAsText with a tag value as a way of setting the value and the use of getAsText to identify the current value.

Returns:

The tag values for this property. May be null if this property cannot be represented as a tagged value.

getCustomEditor

Component getCustomEditor()

Returns:

A java.awt.Component that will allow a human to directly edit the current property value. May be null if this is not supported.

supportsCustomEditor

boolean supportsCustomEditor()

Determines whether this property editor supports a custom editor.

Returns:

True if the propertyEditor can provide a custom editor.

addPropertyChangeListener

void addPropertyChangeListener(PropertyChangeListener listener)

Adds a listener for the value change. When the property editor changes its value it should fire a PropertyChangeEvent on all registered PropertyChangeListeners, specifying the null value for the property name and itself as the source.

Parameters:

listener - the PropertyChangeListener to add

removePropertyChangeListener

void removePropertyChangeListener(PropertyChangeListener listener)

Removes a listener for the value change.

Parameters:

listener - the PropertyChangeListener to remove