Serializable
, AbstractDocument.AttributeContext
public class StyleSheet extends StyleContext
toString
method is required to return a string representation of CSS value. The primary entry point for HTML View implementations to get their attributes is the getViewAttributes
method. This should be implemented to establish the desired policy used to associate attributes with the view. Each HTMLEditorKit (i.e. and therefore each associated JEditorPane) can have its own StyleSheet, but by default one sheet will be shared by all of the HTMLEditorKit instances. HTMLDocument instance can also have a StyleSheet, which holds the document-specific CSS specifications.
In order for Views to store less state and therefore be more lightweight, the StyleSheet can act as a factory for painters that handle some of the rendering tasks. This allows implementations to determine what they want to cache and have the sharing potentially at the level that a selector is common to multiple views. Since the StyleSheet may be used by views over multiple documents and typically the HTML attributes don't effect the selector being used, the potential for sharing is significant.
The rules are stored as named styles, and other information is stored to translate the context of an element to a rule quickly. The following code fragment will display the named styles, and therefore the CSS rules contained.
import java.util.*;
import javax.swing.text.*;
import javax.swing.text.html.*;
public class ShowStyles {
public static void main(String[] args) {
HTMLEditorKit kit = new HTMLEditorKit();
HTMLDocument doc = (HTMLDocument) kit.createDefaultDocument();
StyleSheet styles = doc.getStyleSheet();
Enumeration rules = styles.getStyleNames();
while (rules.hasMoreElements()) {
String name = (String) rules.nextElement();
Style rule = styles.getStyle(name);
System.out.println(rule.toString());
}
System.exit(0);
}
}
The semantics for when a CSS style should override visual attributes defined by an element are not well defined. For example, the html <body bgcolor=red>
makes the body have a red background. But if the html file also contains the CSS rule body { background: blue }
it becomes less clear as to what color the background of the body should be. The current implementation gives visual attributes defined in the element the highest precedence, that is they are always checked before any styles. Therefore, in the previous example the background would have a red color as the body element defines the background color to be red.
As already mentioned this supports CSS. We don't support the full CSS spec. Refer to the javadoc of the CSS class to see what properties we support. The two major CSS parsing related concepts we do not currently support are pseudo selectors, such as A:link { color: red }
, and the important
modifier.
Modifier and Type | Class | Description |
---|---|---|
static final class |
StyleSheet.BoxPainter |
Class to carry out some of the duties of CSS formatting. |
static final class |
StyleSheet.ListPainter |
Class to carry out some of the duties of CSS list formatting. |
StyleContext.NamedStyle, StyleContext.SmallAttributeSet
DEFAULT_STYLE
Constructor | Description |
---|---|
StyleSheet() |
Construct a StyleSheet |
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 |
addCSSAttribute |
Adds a CSS attribute to the given set. |
boolean |
addCSSAttributeFromHTML |
Adds a CSS attribute to the given set. |
void |
addRule |
Adds a set of rules to the sheet. |
void |
addStyleSheet |
Adds the rules from the StyleSheet ss to those of the receiver. |
protected MutableAttributeSet |
createLargeAttributeSet |
Creates a large set of attributes that should trade off space for time. |
protected StyleContext.SmallAttributeSet |
createSmallAttributeSet |
Creates a compact set of attributes that might be shared. |
Color |
getBackground |
Takes a set of attributes and turn it into a background color specification. |
URL |
getBase() |
Returns the base. |
StyleSheet.BoxPainter |
getBoxPainter |
Fetches the box formatter to use for the given set of CSS attributes. |
AttributeSet |
getDeclaration |
Translates a CSS declaration to an AttributeSet that represents the CSS declaration. |
Font |
getFont |
Fetches the font to use for the given set of attributes. |
Color |
getForeground |
Takes a set of attributes and turn it into a foreground color specification. |
static int |
getIndexOfSize |
Returns the index of HTML/CSS size model. |
StyleSheet.ListPainter |
getListPainter |
Fetches the list formatter to use for the given set of CSS attributes. |
float |
getPointSize |
Returns the point size, given a size index. |
float |
getPointSize |
Given a string such as "+2", "-2", or "2", returns a point size value. |
Style |
getRule |
Fetches the rule that best matches the selector given in string form. |
Style |
getRule |
Fetches the style to use to render the given type of HTML tag. |
StyleSheet[] |
getStyleSheets() |
Returns an array of the linked StyleSheets. |
AttributeSet |
getViewAttributes |
Fetches a set of attributes to use in the view for displaying. |
void |
importStyleSheet |
Imports a style sheet from url . |
void |
loadRules |
Loads a set of rules that have been specified in terms of CSS1 grammar. |
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. |
void |
removeStyle |
Removes a named style previously added to the document. |
void |
removeStyleSheet |
Removes the StyleSheet ss from those of the receiver. |
void |
setBase |
Sets the base. |
void |
setBaseFontSize |
Sets the base font size, with valid values between 1 and 7. |
void |
setBaseFontSize |
Sets the base font size from the passed in String. |
Color |
stringToColor |
Converts a color string such as "RED" or "#NNNNNN" to a Color. |
AttributeSet |
translateHTMLToCSS |
Converts a set of HTML attributes to an equivalent set of CSS attributes. |
addChangeListener, addStyle, getChangeListeners, getCompressionThreshold, getDefaultStyleContext, getEmptySet, getFont, getFontMetrics, getStaticAttribute, getStaticAttributeKey, getStyle, getStyleNames, readAttributes, readAttributeSet, reclaim, registerStaticAttributeKey, removeChangeListener, toString, writeAttributes, writeAttributeSet
public StyleSheet()
public Style getRule(HTML.Tag t, Element e)
t
- the type to translate to visual attributese
- the element representing the tag; the element can be used to determine the nesting for situations where the attributes will differ if nested inside of other elementspublic Style getRule(String selector)
selector
is a space separated String of the element names. For example, selector
might be 'html body tr td''The attributes of the returned Style will change as rules are added and removed. That is if you to ask for a rule with a selector "table p" and a new rule was added with a selector of "p" the returned Style would include the new attributes from the rule "p".
selector
- a space separated String of the element names.public void addRule(String rule)
rule
- a set of rulespublic AttributeSet getDeclaration(String decl)
decl
- a CSS declarationpublic void loadRules(Reader in, URL ref) throws IOException
in
- the stream to read the CSS grammar fromref
- the reference URL. This value represents the location of the stream and may be null. All relative URLs specified in the stream will be based upon this parameter.IOException
- if I/O error occurred.public AttributeSet getViewAttributes(View v)
v
- a viewpublic void removeStyle(String nm)
removeStyle
in class StyleContext
nm
- the name of the style to removepublic void addStyleSheet(StyleSheet ss)
ss
to those of the receiver. ss's
rules will override the rules of any previously added style sheets. An added StyleSheet will never override the rules of the receiving style sheet.ss
- a StyleSheetpublic void removeStyleSheet(StyleSheet ss)
ss
from those of the receiver.ss
- a StyleSheetpublic StyleSheet[] getStyleSheets()
public void importStyleSheet(URL url)
url
. The resulting rules are directly added to the receiver. If you do not want the rules to become part of the receiver, create a new StyleSheet and use addStyleSheet to link it in.url
- an urlpublic void setBase(URL base)
base
.base
- a base.public URL getBase()
public void addCSSAttribute(MutableAttributeSet attr, CSS.Attribute key, String value)
attr
- a set of attributeskey
- a CSS propertyvalue
- an HTML attribute valuepublic boolean addCSSAttributeFromHTML(MutableAttributeSet attr, CSS.Attribute key, String value)
attr
- a set of attributeskey
- a CSS propertyvalue
- an HTML attribute valuetrue
if an HTML attribute value
can be converted to a CSS attribute, false otherwise.public AttributeSet translateHTMLToCSS(AttributeSet htmlAttrSet)
htmlAttrSet
- AttributeSet containing the HTML attributes.public AttributeSet addAttribute(AttributeSet old, Object key, Object value)
addAttribute
in interface AbstractDocument.AttributeContext
addAttribute
in class StyleContext
old
- the old attribute setkey
- the non-null attribute keyvalue
- the attribute valuepublic AttributeSet addAttributes(AttributeSet old, AttributeSet attr)
addAttributes
in interface AbstractDocument.AttributeContext
addAttributes
in class StyleContext
old
- the old attribute setattr
- the attributes to addpublic AttributeSet removeAttribute(AttributeSet old, Object key)
removeAttribute
in interface AbstractDocument.AttributeContext
removeAttribute
in class StyleContext
old
- the old set of attributeskey
- the non-null attribute namepublic AttributeSet removeAttributes(AttributeSet old, Enumeration<?> names)
removeAttributes
in interface AbstractDocument.AttributeContext
removeAttributes
in class StyleContext
old
- the old attribute setnames
- the attribute namespublic AttributeSet removeAttributes(AttributeSet old, AttributeSet attrs)
removeAttributes
in interface AbstractDocument.AttributeContext
removeAttributes
in class StyleContext
old
- the old attribute setattrs
- the attributesprotected StyleContext.SmallAttributeSet createSmallAttributeSet(AttributeSet a)
createSmallAttributeSet
in class StyleContext
a
- The set of attributes to be represented in the the compact form.protected MutableAttributeSet createLargeAttributeSet(AttributeSet a)
createLargeAttributeSet
in class StyleContext
a
- The set of attributes to be represented in the the larger form.public Font getFont(AttributeSet a)
getFont
in class StyleContext
a
- the attribute setpublic Color getForeground(AttributeSet a)
getForeground
in class StyleContext
a
- the set of attributespublic Color getBackground(AttributeSet a)
getBackground
in class StyleContext
a
- the set of attributespublic StyleSheet.BoxPainter getBoxPainter(AttributeSet a)
a
- a set of CSS attributespublic StyleSheet.ListPainter getListPainter(AttributeSet a)
a
- a set of CSS attributespublic void setBaseFontSize(int sz)
sz
- a font size.public void setBaseFontSize(String size)
size
- a font size.public static int getIndexOfSize(float pt)
pt
- a size of pointpublic float getPointSize(int index)
index
- a size indexpublic float getPointSize(String size)
size
- a CSS string describing font sizepublic Color stringToColor(String string)
string
- color string such as "RED" or "#NNNNNN"
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
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https://docs.oracle.com/en/java/javase/21/docs/api/java.desktop/javax/swing/text/html/StyleSheet.html