APIdia Launch Partner
Top Description Methods
java.beans

public Interface PropertyEditor

Known Direct Implementers
java.beans.PropertyEditorSupport, com.sun.beans.editors.ColorEditor, com.sun.beans.editors.EnumEditor, com.sun.beans.editors.FontEditor

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.

Since
1.1

Method Summary

Modifier and TypeMethod and Description
public void
addPropertyChangeListener(PropertyChangeListener listener)

Adds a listener for the value change.

public String

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().

getAsText
()

Gets the property value as text.

public Component

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.
getCustomEditor
()

A PropertyEditor may choose to make available a full custom Component that edits its property value.

public String

Returns:

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

Returns a fragment of Java code that can be used to set a property to match the editors current state.

public String[]

Returns:

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

public Object

Returns:

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

Gets the property value.

public boolean

Returns:

True if the class will honor the paintValue method.
isPaintable
()

Determines whether this property editor is paintable.

public void
paintValue(Graphics
Graphics object to paint into.
gfx
,
Rectangle
Rectangle within graphics object into which we should paint.
box
)

Paint a representation of the value into a given area of screen real estate.

public void
removePropertyChangeListener(PropertyChangeListener listener)

Removes a listener for the value change.

public void
setAsText(String
The string to be parsed.
text
)

Set the property value by parsing a given String.

public void
setValue(Object
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.
value
)

Set (or change) the object that is to be edited.

public boolean

Returns:

True if the propertyEditor can provide a custom editor.
supportsCustomEditor
()

Determines whether this property editor supports a custom editor.

Method Detail

addPropertyChangeListenerback to summary
public 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:PropertyChangeListener

the PropertyChangeListener to add

getAsTextback to summary
public String getAsText()

Gets the property value as text.

Returns:String

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().

getCustomEditorback to summary
public Component getCustomEditor()

A PropertyEditor may choose to make available a full custom Component that edits its property value. It is the responsibility of the PropertyEditor to hook itself up to its editor Component itself and to report property value changes by firing a PropertyChange event.

The higher-level code that calls getCustomEditor may either embed the Component in some larger property sheet, or it may put it in its own individual dialog, or ...

Returns:Component

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

getJavaInitializationStringback to summary
public String getJavaInitializationString()

Returns a fragment of Java code that can be used to set a property to match the editors current state. This method is intended for use when generating Java code to reflect changes made through the property editor.

The code fragment should be context free and must be a legal Java expression as specified by the JLS.

Specifically, if the expression represents a computation then all classes and static members should be fully qualified. This rule applies to constructors, static methods and non primitive arguments.

Caution should be used when evaluating the expression as it may throw exceptions. In particular, code generators must ensure that generated code will compile in the presence of an expression that can throw checked exceptions.

Example results are:

  • Primitive expression: 2
  • Class constructor: new java.awt.Color(127,127,34)
  • Static field: java.awt.Color.orange
  • Static method: javax.swing.Box.createRigidArea(new java.awt.Dimension(0, 5))
Returns:String

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

getTagsback to summary
public 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:String[]

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

getValueback to summary
public Object getValue()

Gets the property value.

Returns:Object

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

isPaintableback to summary
public boolean isPaintable()

Determines whether this property editor is paintable.

Returns:boolean

True if the class will honor the paintValue method.

paintValueback to summary
public void paintValue(Graphics gfx, Rectangle box)

Paint a representation of the value into a given area of screen real estate. Note that the propertyEditor is responsible for doing its own clipping so that it fits into the given rectangle.

If the PropertyEditor doesn't honor paint requests (see isPaintable) this method should be a silent noop.

The given Graphics object will have the default font, color, etc of the parent container. The PropertyEditor may change graphics attributes such as font and color and doesn't need to restore the old values.

Parameters
gfx:Graphics

Graphics object to paint into.

box:Rectangle

Rectangle within graphics object into which we should paint.

removePropertyChangeListenerback to summary
public void removePropertyChangeListener(PropertyChangeListener listener)

Removes a listener for the value change.

Parameters
listener:PropertyChangeListener

the PropertyChangeListener to remove

setAsTextback to summary
public 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:String

The string to be parsed.

setValueback to summary
public 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:Object

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.

supportsCustomEditorback to summary
public boolean supportsCustomEditor()

Determines whether this property editor supports a custom editor.

Returns:boolean

True if the propertyEditor can provide a custom editor.