Serializable
, AbstractDocument.AttributeContext
StyleSheet
public class StyleContext extends Object implements Serializable, AbstractDocument.AttributeContext
This class also provides efficient support for small sets of attributes and compresses them by sharing across uses and taking advantage of their immutable nature. Since many styles are replicated, the potential for sharing is significant, and copies can be extremely cheap. Larger sets reduce the possibility of sharing, and therefore revert automatically to a less space-efficient implementation.
Warning: Serialized objects of this class will not be compatible with future Swing releases. The current serialization support is appropriate for short term storage or RMI between applications running the same version of Swing. As of 1.4, support for long term storage of all JavaBeans has been added to the java.beans
package. Please see XMLEncoder
.
Modifier and Type | Class | Description |
---|---|---|
class |
StyleContext.NamedStyle |
A collection of attributes, typically used to represent character and paragraph styles. |
class |
StyleContext.SmallAttributeSet |
This class holds a small number of attributes in an array. |
Modifier and Type | Field | Description |
---|---|---|
static final String |
DEFAULT_STYLE |
The name given to the default logical style attached to paragraphs. |
Constructor | Description |
---|---|
StyleContext() |
Creates a new StyleContext object. |
Modifier and Type | Method | Description |
---|---|---|
AttributeSet |
addAttribute |
Adds an attribute to the given set, and returns the new representative set. |
AttributeSet |
addAttributes |
Adds a set of attributes to the element. |
void |
addChangeListener |
Adds a listener to track when styles are added or removed. |
Style |
addStyle |
Adds a new style into the style hierarchy. |
protected MutableAttributeSet |
createLargeAttributeSet |
Create a large set of attributes that should trade off space for time. |
protected StyleContext.SmallAttributeSet |
createSmallAttributeSet |
Create a compact set of attributes that might be shared. |
Color |
getBackground |
Takes a set of attributes and turn it into a background color specification. |
ChangeListener[] |
getChangeListeners() |
Returns an array of all the ChangeListener s added to this StyleContext with addChangeListener(). |
protected int |
getCompressionThreshold() |
Returns the maximum number of key/value pairs to try and compress into unique/immutable sets. |
static final StyleContext |
getDefaultStyleContext() |
Returns default AttributeContext shared by all documents that don't bother to define/supply their own context. |
AttributeSet |
getEmptySet() |
Fetches an empty AttributeSet. |
Font |
getFont |
Gets a new font. |
Font |
getFont |
Gets the font from an attribute set. |
FontMetrics |
getFontMetrics |
Returns font metrics for a font. |
Color |
getForeground |
Takes a set of attributes and turn it into a foreground color specification. |
static Object |
getStaticAttribute |
Returns the object previously registered with registerStaticAttributeKey . |
static Object |
getStaticAttributeKey |
Returns the String that key will be registered with. |
Style |
getStyle |
Fetches a named style previously added to the document |
Enumeration |
getStyleNames() |
Fetches the names of the styles defined. |
void |
readAttributes |
Context-specific handling of reading in attributes |
static void |
readAttributeSet |
Reads a set of attributes from the given object input stream that have been previously written out with writeAttributeSet . |
void |
reclaim |
Returns a set no longer needed by the MutableAttributeSet implementation. |
static void |
registerStaticAttributeKey |
Registers an object as a static object that is being used as a key in attribute sets. |
AttributeSet |
removeAttribute |
Removes an attribute from the set. |
AttributeSet |
removeAttributes |
Removes a set of attributes for the element. |
AttributeSet |
removeAttributes |
Removes a set of attributes for the element. |
void |
removeChangeListener |
Removes a listener that was tracking styles being added or removed. |
void |
removeStyle |
Removes a named style previously added to the document. |
String |
toString() |
Converts a StyleContext to a String. |
void |
writeAttributes |
Context-specific handling of writing out attributes |
static void |
writeAttributeSet |
Writes a set of attributes to the given object stream for the purpose of serialization. |
public static final String DEFAULT_STYLE
public StyleContext()
public static final StyleContext getDefaultStyleContext()
public Style addStyle(String nm, Style parent)
nm
- the name of the style (must be unique within the collection of named styles in the document). The name may be null if the style is unnamed, but the caller is responsible for managing the reference returned as an unnamed style can't be fetched by name. An unnamed style may be useful for things like character attribute overrides such as found in a style run.parent
- the parent style. This may be null if unspecified attributes need not be resolved in some other style.public void removeStyle(String nm)
nm
- the name of the style to removepublic Style getStyle(String nm)
nm
- the name of the stylepublic Enumeration<?> getStyleNames()
public void addChangeListener(ChangeListener l)
l
- the change listenerpublic void removeChangeListener(ChangeListener l)
l
- the change listenerpublic ChangeListener[] getChangeListeners()
ChangeListener
s added to this StyleContext with addChangeListener().ChangeListener
s added or an empty array if no listeners have been addedpublic Font getFont(AttributeSet attr)
attr
- the attribute setpublic Color getForeground(AttributeSet attr)
attr
- the set of attributespublic Color getBackground(AttributeSet attr)
attr
- the set of attributespublic Font getFont(String family, int style, int size)
family
- the font family (such as "Monospaced")style
- the style of the font (such as Font.PLAIN)size
- the point size >= 1public FontMetrics getFontMetrics(Font f)
f
- the fontpublic AttributeSet addAttribute(AttributeSet old, Object name, Object value)
This method is thread safe, although most Swing methods are not. Please see Concurrency in Swing for more information.
addAttribute
in interface AbstractDocument.AttributeContext
old
- the old attribute setname
- the non-null attribute namevalue
- the attribute valuepublic AttributeSet addAttributes(AttributeSet old, AttributeSet attr)
This method is thread safe, although most Swing methods are not. Please see Concurrency in Swing for more information.
addAttributes
in interface AbstractDocument.AttributeContext
old
- the old attribute setattr
- the attributes to addpublic AttributeSet removeAttribute(AttributeSet old, Object name)
This method is thread safe, although most Swing methods are not. Please see Concurrency in Swing for more information.
removeAttribute
in interface AbstractDocument.AttributeContext
old
- the old set of attributesname
- the non-null attribute namepublic AttributeSet removeAttributes(AttributeSet old, Enumeration<?> names)
This method is thread safe, although most Swing methods are not. Please see Concurrency in Swing for more information.
removeAttributes
in interface AbstractDocument.AttributeContext
old
- the old attribute setnames
- the attribute namespublic AttributeSet removeAttributes(AttributeSet old, AttributeSet attrs)
This method is thread safe, although most Swing methods are not. Please see Concurrency in Swing for more information.
removeAttributes
in interface AbstractDocument.AttributeContext
old
- the old attribute setattrs
- the attributespublic AttributeSet getEmptySet()
getEmptySet
in interface AbstractDocument.AttributeContext
public void reclaim(AttributeSet a)
This method is thread safe, although most Swing methods are not. Please see Concurrency in Swing for more information.
reclaim
in interface AbstractDocument.AttributeContext
a
- the set to reclaimprotected int getCompressionThreshold()
protected StyleContext.SmallAttributeSet createSmallAttributeSet(AttributeSet a)
a
- The set of attributes to be represented in the the compact form.protected MutableAttributeSet createLargeAttributeSet(AttributeSet a)
a
- The set of attributes to be represented in the the larger form.public String toString()
public void writeAttributes(ObjectOutputStream out, AttributeSet a) throws IOException
out
- the output streama
- the attribute setIOException
- on any I/O errorpublic void readAttributes(ObjectInputStream in, MutableAttributeSet a) throws ClassNotFoundException, IOException
in
- the object stream to read the attribute data from.a
- the attribute set to place the attribute definitions in.ClassNotFoundException
- passed upward if encountered when reading the object stream.IOException
- passed upward if encountered when reading the object stream.public static void writeAttributeSet(ObjectOutputStream out, AttributeSet a) throws IOException
registerStaticAttributeKey
method. Any attribute key not registered as a static key will be serialized directly. All values are expected to be serializable.out
- the output streama
- the attribute setIOException
- on any I/O errorpublic static void readAttributeSet(ObjectInputStream in, MutableAttributeSet a) throws ClassNotFoundException, IOException
writeAttributeSet
. This will try to restore keys that were static objects to the static objects in the current virtual machine considering only those keys that have been registered with the registerStaticAttributeKey
method. The attributes retrieved from the stream will be placed into the given mutable set.in
- the object stream to read the attribute data from.a
- the attribute set to place the attribute definitions in.ClassNotFoundException
- passed upward if encountered when reading the object stream.IOException
- passed upward if encountered when reading the object stream.public static void registerStaticAttributeKey(Object key)
For operation under a 1.1 virtual machine, this uses the value returned by toString
concatenated to the classname. The value returned by toString should not have the class reference in it (ie it should be reimplemented from the definition in Object) in order to be the same when recomputed later.
key
- the non-null object keypublic static Object getStaticAttribute(Object key)
registerStaticAttributeKey
.key
- the object keyregisterStaticAttributeKey
public static Object getStaticAttributeKey(Object key)
key
will be registered with.key
- the object keykey
will be registered with
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https://docs.oracle.com/en/java/javase/21/docs/api/java.desktop/javax/swing/text/StyleContext.html