javax.swing.text.html

Class StyleSheet

Implemented Interfaces:
AbstractDocument.AttributeContext, Serializable

public class StyleSheet
extends StyleContext

Support for defining the visual characteristics of HTML views being rendered. The StyleSheet is used to translate the HTML model into visual characteristics. This enables views to be customized by a look-and-feel, multiple views over the same model can be rendered differently, etc. This can be thought of as a CSS rule repository. The key for CSS attributes is an object of type CSS.Attribute. The type of the value is up to the StyleSheet implementation, but the 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 overide 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 implemention 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.

Note: This implementation is currently incomplete. It can be replaced with alternative implementations that are complete. Future versions of this class will provide better CSS support.

See Also:
Serialized Form

Nested Class Summary

static class
StyleSheet.BoxPainter
Class to carry out some of the duties of CSS formatting.
static class
StyleSheet.ListPainter
Class to carry out some of the duties of CSS list formatting.

Nested classes/interfaces inherited from class javax.swing.text.StyleContext

StyleContext.NamedStyle, StyleContext.SmallAttributeSet

Field Summary

Fields inherited from class javax.swing.text.StyleContext

DEFAULT_STYLE

Constructor Summary

StyleSheet()
Construct a StyleSheet

Method Summary

AttributeSet
addAttribute(AttributeSet old, Object key, Object value)
Adds an attribute to the given set, and returns the new representative set.
AttributeSet
addAttributes(AttributeSet old, AttributeSet attr)
Adds a set of attributes to the element.
void
addCSSAttribute(MutableAttributeSet attr, CSS.Attribute key, String value)
Adds a CSS attribute to the given set.
boolean
addCSSAttributeFromHTML(MutableAttributeSet attr, CSS.Attribute key, String value)
Adds a CSS attribute to the given set.
void
addRule(String rule)
Adds a set of rules to the sheet.
void
addStyleSheet(StyleSheet ss)
Adds the rules from the StyleSheet ss to those of the receiver.
protected MutableAttributeSet
createLargeAttributeSet(AttributeSet a)
Creates a large set of attributes that should trade off space for time.
protected StyleContext.SmallAttributeSet
createSmallAttributeSet(AttributeSet a)
Creates a compact set of attributes that might be shared.
Color
getBackground(AttributeSet a)
Takes a set of attributes and turn it into a background color specification.
URL
getBase()
Returns the base.
StyleSheet.BoxPainter
getBoxPainter(AttributeSet a)
Fetches the box formatter to use for the given set of CSS attributes.
AttributeSet
getDeclaration(String decl)
Translates a CSS declaration to an AttributeSet that represents the CSS declaration.
Font
getFont(AttributeSet a)
Fetches the font to use for the given set of attributes.
Color
getForeground(AttributeSet a)
Takes a set of attributes and turn it into a foreground color specification.
static int
getIndexOfSize(float pt)
StyleSheet.ListPainter
getListPainter(AttributeSet a)
Fetches the list formatter to use for the given set of CSS attributes.
float
getPointSize(int index)
Returns the point size, given a size index.
float
getPointSize(String size)
Given a string such as "+2", "-2", or "2", returns a point size value.
Style
getRule(String selector)
Fetches the rule that best matches the selector given in string form.
Style
getRule(HTML.Tag t, Element e)
Fetches the style to use to render the given type of HTML tag.
StyleSheet[]
getStyleSheets()
Returns an array of the linked StyleSheets.
AttributeSet
getViewAttributes(View v)
Fetches a set of attributes to use in the view for displaying.
void
importStyleSheet(URL url)
Imports a style sheet from url.
void
loadRules(Reader in, URL ref)
Loads a set of rules that have been specified in terms of CSS1 grammar.
AttributeSet
removeAttribute(AttributeSet old, Object key)
Removes an attribute from the set.
AttributeSet
removeAttributes(AttributeSet old, Enumeration names)
Removes a set of attributes for the element.
AttributeSet
removeAttributes(AttributeSet old, AttributeSet attrs)
Removes a set of attributes.
void
removeStyle(String nm)
Removes a named style previously added to the document.
void
removeStyleSheet(StyleSheet ss)
Removes the StyleSheet ss from those of the receiver.
void
setBase(URL base)
Sets the base.
void
setBaseFontSize(int sz)
Sets the base font size, with valid values between 1 and 7.
void
setBaseFontSize(String size)
Sets the base font size from the passed in String.
Color
stringToColor(String string)
Converts a color string such as "RED" or "#NNNNNN" to a Color.
AttributeSet
translateHTMLToCSS(AttributeSet htmlAttrSet)
Converts a set of HTML attributes to an equivalent set of CSS attributes.

Methods inherited from class javax.swing.text.StyleContext

addAttribute, addAttributes, addChangeListener, addStyle, createLargeAttributeSet, createSmallAttributeSet, getBackground, getChangeListeners, getCompressionThreshold, getDefaultStyleContext, getEmptySet, getFont, getFont, getFontMetrics, getForeground, getStaticAttribute, getStaticAttributeKey, getStyle, getStyleNames, readAttributeSet, readAttributes, reclaim, registerStaticAttributeKey, removeAttribute, removeAttributes, removeAttributes, removeChangeListener, removeStyle, toString, writeAttributeSet, writeAttributes

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

StyleSheet

public StyleSheet()
Construct a StyleSheet
Usages and Demos :

View More Examples of StyleSheet()
   1:     public Document createDefaultDocument() {
   2:         StyleSheet styles = new StyleSheet();
   3:         styles.addRule(
   4:             "a {" +
   5:             "color: blue;" +

View Full Code Here
   1:         StyleSheet styles = getStyleSheet();
   2:         StyleSheet ss = new StyleSheet();
   3:         ss.addStyleSheet(styles);
   4:         ExtendedHTMLDocument doc = new ExtendedHTMLDocument(ss);
   5:         doc.setParser(getParser());

View Full Code Here
   1:         StyleSheet styles = getStyleSheet();
   2:         StyleSheet ss = new StyleSheet();
   3:         ss.addStyleSheet(styles);
   4:         ExtendedHTMLDocument doc = new ExtendedHTMLDocument(ss);
   5:         doc.setParser(getParser());

View Full Code Here
   1:         StyleSheet styles = getStyleSheet();
   2:         StyleSheet ss = new StyleSheet();
   3:     
   4:         ss.addStyleSheet(styles);
   5:     

View Full Code Here
   1:         if (!gotStyles) {
   2:             StyleSheet dss = new StyleSheet();
   3:             gotStyles= true;
   4:             try {
   5:                 InputStream is = AppResources.global.getStream("readseq.css");

View Full Code Here

Method Details

addAttribute

public AttributeSet addAttribute(AttributeSet old,
                                 Object key,
                                 Object value)
Adds an attribute to the given set, and returns the new representative set. This is reimplemented to convert StyleConstant attributes to CSS prior to forwarding to the superclass behavior. The StyleConstants attribute has no corresponding CSS entry, the StyleConstants attribute is stored (but will likely be unused).
Specified by:
addAttribute in interface AbstractDocument.AttributeContext
Overrides:
addAttribute in interface StyleContext
Parameters:
old - the old attribute set
key - the non-null attribute key
value - the attribute value
Returns:
the updated attribute set

addAttributes

public AttributeSet addAttributes(AttributeSet old,
                                  AttributeSet attr)
Adds a set of attributes to the element. If any of these attributes are StyleConstants attributes, they will be converted to CSS prior to forwarding to the superclass behavior.
Specified by:
addAttributes in interface AbstractDocument.AttributeContext
Overrides:
addAttributes in interface StyleContext
Parameters:
old - the old attribute set
attr - the attributes to add
Returns:
the updated attribute set

addCSSAttribute

public void addCSSAttribute(MutableAttributeSet attr,
                            CSS.Attribute key,
                            String value)
Adds a CSS attribute to the given set.
Since:
1.3

addCSSAttributeFromHTML

public boolean addCSSAttributeFromHTML(MutableAttributeSet attr,
                                       CSS.Attribute key,
                                       String value)
Adds a CSS attribute to the given set.
Since:
1.3

addRule

public void addRule(String rule)
Adds a set of rules to the sheet. The rules are expected to be in valid CSS format. Typically this would be called as a result of parsing a <style> tag.
Usages and Demos :

View More Examples of addRule(String rule)
   1:             {
   2:                 StyleSheet style = ((HTMLDocument)getDocument()).getStyleSheet();                
   3:         ...
   4:                 style.addRule(rule.toString());
   5:             }
   6:             catch (RuntimeException re)
   7:             {

View Full Code Here

addStyleSheet

public void addStyleSheet(StyleSheet ss)
Adds the rules from the StyleSheet 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.
Since:
1.3

createLargeAttributeSet

protected MutableAttributeSet createLargeAttributeSet(AttributeSet a)
Creates a large set of attributes that should trade off space for time. This set will not be shared. This is a hook for subclasses that want to alter the behavior of the larger attribute storage format (which is SimpleAttributeSet by default). This can be reimplemented to return a MutableAttributeSet that provides some sort of attribute conversion.
Overrides:
createLargeAttributeSet in interface StyleContext
Parameters:
a - The set of attributes to be represented in the the larger form.

createSmallAttributeSet

protected StyleContext.SmallAttributeSet createSmallAttributeSet(AttributeSet a)
Creates a compact set of attributes that might be shared. This is a hook for subclasses that want to alter the behavior of SmallAttributeSet. This can be reimplemented to return an AttributeSet that provides some sort of attribute conversion.
Overrides:
createSmallAttributeSet in interface StyleContext
Parameters:
a - The set of attributes to be represented in the the compact form.

getBackground

public Color getBackground(AttributeSet a)
Takes a set of attributes and turn it into a background color specification. This might be used to specify things like brighter, more hue, etc.
Overrides:
getBackground in interface StyleContext
Parameters:
a - the set of attributes
Returns:
the color

getBase

public URL getBase()
Returns the base.
Since:
1.3

getBoxPainter

public StyleSheet.BoxPainter getBoxPainter(AttributeSet a)
Fetches the box formatter to use for the given set of CSS attributes.

getDeclaration

public AttributeSet getDeclaration(String decl)
Translates a CSS declaration to an AttributeSet that represents the CSS declaration. Typically this would be called as a result of encountering an HTML style attribute.

getFont

public Font getFont(AttributeSet a)
Fetches the font to use for the given set of attributes.
Overrides:
getFont in interface StyleContext

getForeground

public Color getForeground(AttributeSet a)
Takes a set of attributes and turn it into a foreground color specification. This might be used to specify things like brighter, more hue, etc.
Overrides:
getForeground in interface StyleContext
Parameters:
a - the set of attributes
Returns:
the color

getIndexOfSize

public static int getIndexOfSize(float pt)

getListPainter

public StyleSheet.ListPainter getListPainter(AttributeSet a)
Fetches the list formatter to use for the given set of CSS attributes.

getPointSize

public float getPointSize(int index)
Returns the point size, given a size index.
Usages and Demos :

View More Examples of getPointSize(int index)
   1: import javax.swing.text.html.HTMLDocument;
   2: import javax.swing.text.html.StyleSheet;
   3: import javax.help.*;
   4:         ...
   5:     int newsize, tmp;
   6:     StyleSheet css = doc.getStyleSheet();
   7:     try {
   8:         ...
   9:         if (size.equals("xx-small")) {
  10:         newsize = (int)css.getPointSize(0);
  11:         } else if (size.equals("x-small")) {
  12:         ...
  13:         newsize = (int)css.getPointSize(1);

View Full Code Here

getPointSize

public float getPointSize(String size)
Given a string such as "+2", "-2", or "2", returns a point size value.
Usages and Demos :

View More Examples of getPointSize(String size)
   1: import javax.swing.text.html.HTMLDocument;
   2: import javax.swing.text.html.StyleSheet;
   3: import javax.help.*;
   4:         ...
   5:     int newsize, tmp;
   6:     StyleSheet css = doc.getStyleSheet();
   7:     try {
   8:         ...
   9:         if (size.equals("xx-small")) {
  10:         newsize = (int)css.getPointSize(0);
  11:         } else if (size.equals("x-small")) {
  12:         ...
  13:         newsize = (int)css.getPointSize(1);

View Full Code Here

getRule

public Style getRule(String selector)
Fetches the rule that best matches the selector given in string form. Where 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".


getRule

public Style getRule(HTML.Tag t,
                     Element e)
Fetches the style to use to render the given type of HTML tag. The element given is representing the tag and can be used to determine the nesting for situations where the attributes will differ if nesting inside of elements.
Parameters:
t - the type to translate to visual attributes
e - 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 elements
Returns:
the set of CSS attributes to use to render the tag

getStyleSheets

public StyleSheet[] getStyleSheets()
Returns an array of the linked StyleSheets. Will return null if there are no linked StyleSheets.
Since:
1.3
Usages and Demos :

View More Examples of getStyleSheets()
   1:     {
   2:       StyleSheet ss=hd.getStyleSheet();
   3: 
   4:         ...
   5:       StyleSheet[] as=ss.getStyleSheets();
   6:       if(as!=null)
   7:         ...
   8: 
   9:   private static final void updateStyles(StyleSheet _styles)
  10:   {

View Full Code Here

getViewAttributes

public AttributeSet getViewAttributes(View v)
Fetches a set of attributes to use in the view for displaying. This is basically a set of attributes that can be used for View.getAttributes.
Usages and Demos :

View More Examples of getViewAttributes(View v)
   1: import javax.swing.text.html.HTMLDocument;
   2: import javax.swing.text.html.StyleSheet;
   3: 
   4:         ...
   5:         initialize(elem);
   6:         StyleSheet sheet = getStyleSheet();
   7:         ...
   8:         this.attr = sheet.getViewAttributes(this);
   9:     }
  10:         ...
  11:     
  12:     protected StyleSheet getStyleSheet() {

View Full Code Here

importStyleSheet

public void importStyleSheet(URL url)
Imports a style sheet from 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.
Since:
1.3

loadRules

public void loadRules(Reader in,
                      URL ref)
            throws IOException
Loads a set of rules that have been specified in terms of CSS1 grammar. If there are collisions with existing rules, the newly specified rule will win.
Parameters:
in - the stream to read the CSS grammar from
ref - 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.

removeAttribute

public AttributeSet removeAttribute(AttributeSet old,
                                    Object key)
Removes an attribute from the set. If the attribute is a StyleConstants attribute, the request will be converted to a CSS attribute prior to forwarding to the superclass behavior.
Specified by:
removeAttribute in interface AbstractDocument.AttributeContext
Overrides:
removeAttribute in interface StyleContext
Parameters:
old - the old set of attributes
key - the non-null attribute name
Returns:
the updated attribute set

removeAttributes

public AttributeSet removeAttributes(AttributeSet old,
                                     Enumeration names)
Removes a set of attributes for the element. If any of the attributes is a StyleConstants attribute, the request will be converted to a CSS attribute prior to forwarding to the superclass behavior.
Specified by:
removeAttributes in interface AbstractDocument.AttributeContext
Overrides:
removeAttributes in interface StyleContext
Parameters:
old - the old attribute set
names - the attribute names
Returns:
the updated attribute set
See Also:
MutableAttributeSet.removeAttributes

removeAttributes

public AttributeSet removeAttributes(AttributeSet old,
                                     AttributeSet attrs)
Removes a set of attributes. If any of the attributes is a StyleConstants attribute, the request will be converted to a CSS attribute prior to forwarding to the superclass behavior.
Specified by:
removeAttributes in interface AbstractDocument.AttributeContext
Overrides:
removeAttributes in interface StyleContext
Parameters:
old - the old attribute set
attrs - the attributes
Returns:
the updated attribute set
See Also:
MutableAttributeSet.removeAttributes

removeStyle

public void removeStyle(String nm)
Removes a named style previously added to the document.
Overrides:
removeStyle in interface StyleContext
Parameters:
nm - the name of the style to remove
Usages and Demos :

View More Examples of removeStyle(String nm)
   1:     {
   2:       StyleSheet ss=hd.getStyleSheet();
   3: 
   4:         ...
   5:       StyleSheet[] as=ss.getStyleSheets();
   6:       if(as!=null)
   7:         ...
   8:         String name=(String)rules.nextElement();
   9:         ss.removeStyle(name);
  10:       }
  11:         ...
  12: 
  13:   private static final void updateStyles(StyleSheet _styles)

View Full Code Here

removeStyleSheet

public void removeStyleSheet(StyleSheet ss)
Removes the StyleSheet ss from those of the receiver.
Since:
1.3
Usages and Demos :

View More Examples of removeStyleSheet(StyleSheet ss)
   1:     {
   2:       StyleSheet ss=hd.getStyleSheet();
   3: 
   4:         ...
   5:       StyleSheet[] as=ss.getStyleSheets();
   6:       if(as!=null)
   7:         ...
   8:         for(int i=0;i<as.length;i++)
   9:           ss.removeStyleSheet(as[i]);
  10: 
  11:         ...
  12: 
  13:   private static final void updateStyles(StyleSheet _styles)

View Full Code Here

setBase

public void setBase(URL base)
Sets the base. All import statements that are relative, will be relative to base.
Since:
1.3

setBaseFontSize

public void setBaseFontSize(int sz)
Sets the base font size, with valid values between 1 and 7.

setBaseFontSize

public void setBaseFontSize(String size)
Sets the base font size from the passed in String. The string can either identify a specific font size, with legal values between 1 and 7, or identifiy a relative font size such as +1 or -2.

stringToColor

public Color stringToColor(String string)
Converts a color string such as "RED" or "#NNNNNN" to a Color. Note: This will only convert the HTML3.2 color strings or a string of length 7; otherwise, it will return null.

translateHTMLToCSS

public AttributeSet translateHTMLToCSS(AttributeSet htmlAttrSet)
Converts a set of HTML attributes to an equivalent set of CSS attributes.
Parameters:
htmlAttrSet - AttributeSet containing the HTML attributes.