public GlyphView(Element elem) 
{
        super(elem);
        offset = 0;
        length = 0;
        Element parent = elem.getParentElement();
        AttributeSet attr = elem.getAttributes();
        //         if there was an implied CR
        impliedCR = (attr != null && attr.getAttribute(IMPLIED_CR) != null &&
        //         if this is non-empty paragraph
                   parent != null && parent.getElementCount()  > 1);
        skipWidth = elem.getName().equals("br");
}

Constructs a new view wrapped on an element.

Parameters:

elem - the element

 public View breakView(int axis,
    int p0,
    float pos,
    float len) 
{
        if (axis == View.X_AXIS) {
            checkPainter();
            int p1 = painter.getBoundedPosition(this, p0, pos, len);
            int breakSpot = getBreakSpot(p0, p1);
            if (breakSpot != -1) {
                p1 = breakSpot;
            }
            // else, no break in the region, return a fragment of the
            // bounded region.
            if (p0 == getStartOffset() && p1 == getEndOffset()) {
                return this;
            }
            GlyphView v = (GlyphView) createFragment(p0, p1);
            v.x = (int) pos;
            return v;
        }
        return this;
}

Breaks this view on the given axis at the given length. This is implemented to attempt to break on a whitespace location, and returns a fragment with the whitespace at the end. If a whitespace location can't be found, the nearest character is used.

 public  void changedUpdate(DocumentEvent e,
    Shape a,
    ViewFactory f) 
{
        minimumSpan = -1;
        syncCR();
        preferenceChanged(null, true, true);
}

Gives notification from the document that attributes were changed in a location that this view is responsible for. This is implemented to call preferenceChanged along both the horizontal and vertical axis.

 protected  void checkPainter() 
{
        if (painter == null) {
            if (defaultPainter == null) {
                // the classname should probably come from a property file.
                String classname = "javax.swing.text.GlyphPainter1";
                try {
                    Class c;
                    ClassLoader loader = getClass().getClassLoader();
                    if (loader != null) {
                        c = loader.loadClass(classname);
                    } else {
                        c = Class.forName(classname);
                    }
                    Object o = c.newInstance();
                    if (o instanceof GlyphPainter) {
                        defaultPainter = (GlyphPainter) o;
                    }
                } catch (Throwable e) {
                    throw new StateInvariantError("GlyphView: Can't load glyph painter: "
                                                  + classname);
                }
            }
            setGlyphPainter(defaultPainter.getPainter(this, getStartOffset(),
                                                      getEndOffset()));
        }
}

Check to see that a glyph painter exists. If a painter doesn't exist, a default glyph painter will be installed.

 protected final Object clone() 
{
        Object o;
        try {
            o = super.clone();
        } catch (CloneNotSupportedException cnse) {
            o = null;
        }
        return o;
}

Creates a shallow copy. This is used by the createFragment and breakView methods.

 public View createFragment(int p0,
    int p1) 
{
        checkPainter();
        Element elem = getElement();
        GlyphView v = (GlyphView) clone();
        v.offset = p0 - elem.getStartOffset();
        v.length = p1 - p0;
        v.painter = painter.getPainter(v, p0, p1);
        v.justificationInfo = null;
        return v;
}

Creates a view that represents a portion of the element. This is potentially useful during formatting operations for taking measurements of fragments of the view. If the view doesn't support fragmenting (the default), it should return itself.

This view does support fragmenting. It is implemented to return a nested class that shares state in this view representing only a portion of the view.

 public float getAlignment(int axis) 
{
        checkPainter();
        if (axis == View.Y_AXIS) {
            boolean sup = isSuperscript();
            boolean sub = isSubscript();
            float h = painter.getHeight(this);
            float d = painter.getDescent(this);
            float a = painter.getAscent(this);
            float align;
            if (sup) {
                align = 1.0f;
            } else if (sub) {
                align = (h  > 0) ? (h - (d + (a / 2))) / h : 0;
            } else {
                align = (h  > 0) ? (h - d) / h : 0;
            }
            return align;
        }
        return super.getAlignment(axis);
}

Determines the desired alignment for this view along an axis. For the label, the alignment is along the font baseline for the y axis, and the superclasses alignment along the x axis.

 public Color getBackground() 
{
        Document doc = getDocument();
        if (doc instanceof StyledDocument) {
            AttributeSet attr = getAttributes();
            if (attr.isDefined(StyleConstants.Background)) {
                return ((StyledDocument)doc).getBackground(attr);
            }
        }
        return null;
}

Fetch the background color to use to render the glyphs. If there is no background color, null should be returned. This is implemented to call StyledDocument.getBackground if the associated document is a styled document, otherwise it returns null.

 public int getBreakWeight(int axis,
    float pos,
    float len) 
{
        if (axis == View.X_AXIS) {
            checkPainter();
            int p0 = getStartOffset();
            int p1 = painter.getBoundedPosition(this, p0, pos, len);
            return p1 == p0 ? View.BadBreakWeight :
                   getBreakSpot(p0, p1) != BreakIterator.DONE ?
                            View.ExcellentBreakWeight : View.GoodBreakWeight;
        }
        return super.getBreakWeight(axis, pos, len);
}

Determines how attractive a break opportunity in this view is. This can be used for determining which view is the most attractive to call breakView on in the process of formatting. The higher the weight, the more attractive the break. A value equal to or lower than View.BadBreakWeight should not be considered for a break. A value greater than or equal to View.ForcedBreakWeight should be broken.

This is implemented to forward to the superclass for the Y_AXIS. Along the X_AXIS the following values may be returned.

View.ExcellentBreakWeight

if there is whitespace proceeding the desired break location.

View.BadBreakWeight

if the desired break location results in a break location of the starting offset.

View.GoodBreakWeight

if the other conditions don't occur.

This will normally result in the behavior of breaking on a whitespace location if one can be found, otherwise breaking between characters.

 public int getEndOffset() 
{
        Element e = getElement();
        return (length  > 0) ? e.getStartOffset() + offset + length : e.getEndOffset();
}

Fetches the portion of the model that this view is responsible for.

 public Font getFont() 
{
        Document doc = getDocument();
        if (doc instanceof StyledDocument) {
            AttributeSet attr = getAttributes();
            return ((StyledDocument)doc).getFont(attr);
        }
        Component c = getContainer();
        if (c != null) {
            return c.getFont();
        }
        return null;
}

Fetch the font that the glyphs should be based upon. This is implemented to call StyledDocument.getFont if the associated document is a StyledDocument. If the associated document is not a StyledDocument, the associated components font is used. If there is no associated component, null is returned.

 public Color getForeground() 
{
        Document doc = getDocument();
        if (doc instanceof StyledDocument) {
            AttributeSet attr = getAttributes();
            return ((StyledDocument)doc).getForeground(attr);
        }
        Component c = getContainer();
        if (c != null) {
            return c.getForeground();
        }
        return null;
}

Fetch the foreground color to use to render the glyphs. If there is no foreground color, null should be returned. This is implemented to call StyledDocument.getBackground if the associated document is a StyledDocument. If the associated document is not a StyledDocument, the associated components foreground color is used. If there is no associated component, null is returned.

 public GlyphPainter getGlyphPainter() 
{
        return painter;
}

Fetch the currently installed glyph painter. If a painter has not yet been installed, and a default was not yet needed, null is returned.

 JustificationInfo getJustificationInfo(int rowStartOffset) 
{
        if (justificationInfo != null) {
            return justificationInfo;
        }
        //states for the parsing
        final int TRAILING = 0;
        final int CONTENT  = 1;
        final int SPACES   = 2;
        int startOffset = getStartOffset();
        int endOffset = getEndOffset();
        Segment segment = getText(startOffset, endOffset);
        int txtOffset = segment.offset;
        int txtEnd = segment.offset + segment.count - 1;
        int startContentPosition = txtEnd + 1;
        int endContentPosition = txtOffset - 1;
        int lastTabPosition = txtOffset - 1;
        int trailingSpaces = 0;
        int contentSpaces = 0;
        int leadingSpaces = 0;
        boolean hasTab = false;
        BitSet spaceMap = new BitSet(endOffset - startOffset + 1);
        //we parse conent to the right of the rightmost TAB only.
        //we are looking for the trailing and leading spaces.
        //position after the leading spaces (startContentPosition)
        //position before the trailing spaces (endContentPosition)
        for (int i = txtEnd, state = TRAILING; i  >= txtOffset; i--) {
            if (' ' == segment.array[i]) {
                spaceMap.set(i - txtOffset);
                if (state == TRAILING) {
                    trailingSpaces++;
                } else if (state == CONTENT) {
                    state = SPACES;
                    leadingSpaces = 1;
                } else if (state == SPACES) {
                    leadingSpaces++;
                }
            } else if ('\t' == segment.array[i]) {
                hasTab = true;
                break;
            } else {
                if (state == TRAILING) {
                    if ('\n' != segment.array[i]
                          && '\r' != segment.array[i]) {
                        state = CONTENT;
                        endContentPosition = i;
                    }
                } else if (state == CONTENT) {
                    //do nothing
                } else if (state == SPACES) {
                    contentSpaces += leadingSpaces;
                    leadingSpaces = 0;
                }
                startContentPosition = i;
            }
        }
        SegmentCache.releaseSharedSegment(segment);
        int startJustifiableContent = -1;
        if (startContentPosition <  txtEnd) {
            startJustifiableContent =
                startContentPosition - txtOffset;
        }
        int endJustifiableContent = -1;
        if (endContentPosition  > txtOffset) {
            endJustifiableContent =
                endContentPosition - txtOffset;
        }
        justificationInfo =
            new JustificationInfo(startJustifiableContent,
                                  endJustifiableContent,
                                  leadingSpaces,
                                  contentSpaces,
                                  trailingSpaces,
                                  hasTab,
                                  spaceMap);
        return justificationInfo;
}

 public float getMinimumSpan(int axis) 
{
        switch (axis) {
            case View.X_AXIS:
                if (minimumSpan <  0) {
                    minimumSpan = 0;
                    int p0 = getStartOffset();
                    int p1 = getEndOffset();
                    while (p1  > p0) {
                        int breakSpot = getBreakSpot(p0, p1);
                        if (breakSpot == BreakIterator.DONE) {
                            // the rest of the view is non-breakable
                            breakSpot = p0;
                        }
                        minimumSpan = Math.max(minimumSpan,
                                getPartialSpan(breakSpot, p1));
                        // Note: getBreakSpot returns the *last* breakspot
                        p1 = breakSpot - 1;
                    }
                }
                return minimumSpan;
            case View.Y_AXIS:
                return super.getMinimumSpan(axis);
            default:
                throw new IllegalArgumentException("Invalid axis: " + axis);
        }
}

Determines the minimum span for this view along an axis.

This implementation returns the longest non-breakable area within the view as a minimum span for {@code View.X_AXIS}.

 public int getNextVisualPositionFrom(int pos,
    Bias b,
    Shape a,
    int direction,
    Bias[] biasRet) throws BadLocationException 
{
        return painter.getNextVisualPositionFrom(this, pos, b, a, direction, biasRet);
}

Provides a way to determine the next visually represented model location that one might place a caret. Some views may not be visible, they might not be in the same order found in the model, or they just might not allow access to some of the locations in the model.

 public float getPartialSpan(int p0,
    int p1) 
{
        checkPainter();
        float width = painter.getSpan(this, p0, p1, expander, x);
        return width;
}

Determines the span along the same axis as tab expansion for a portion of the view. This is intended for use by the TabExpander for cases where the tab expansion involves aligning the portion of text that doesn't have whitespace relative to the tab stop. There is therefore an assumption that the range given does not contain tabs.

This method can be called while servicing the getTabbedSpan or getPreferredSize. It has to arrange for its own text buffer to make the measurements.

 public float getPreferredSpan(int axis) 
{
        if (impliedCR) {
            return 0;
        }
        checkPainter();
        int p0 = getStartOffset();
        int p1 = getEndOffset();
        switch (axis) {
        case View.X_AXIS:
            if (skipWidth) {
                return 0;
            }
            return painter.getSpan(this, p0, p1, expander, this.x);
        case View.Y_AXIS:
            float h = painter.getHeight(this);
            if (isSuperscript()) {
                h += h/3;
            }
            return h;
        default:
            throw new IllegalArgumentException("Invalid axis: " + axis);
        }
}

Determines the preferred span for this view along an axis.

 public int getStartOffset() 
{
        Element e = getElement();
        return (length  > 0) ? e.getStartOffset() + offset : e.getStartOffset();
}

Fetches the portion of the model that this view is responsible for.

 public TabExpander getTabExpander() 
{
        return expander;
}

Fetch the TabExpander to use if tabs are present in this view.

 public float getTabbedSpan(float x,
    TabExpander e) 
{
        checkPainter();
        TabExpander old = expander;
        expander = e;
        if (expander != old) {
            // setting expander can change horizontal span of the view,
            // so we have to call preferenceChanged()
            preferenceChanged(null, true, false);
        }
        this.x = (int) x;
        int p0 = getStartOffset();
        int p1 = getEndOffset();
        float width = painter.getSpan(this, p0, p1, expander, x);
        return width;
}

Determines the desired span when using the given tab expansion implementation.

 public Segment getText(int p0,
    int p1) 
{
         // When done with the returned Segment it should be released by
         // invoking:
         //    SegmentCache.releaseSharedSegment(segment);
         Segment text = SegmentCache.getSharedSegment();
         try {
             Document doc = getDocument();
             doc.getText(p0, p1 - p0, text);
         } catch (BadLocationException bl) {
             throw new StateInvariantError("GlyphView: Stale view: " + bl);
         }
         return text;
}

Fetch a reference to the text that occupies the given range. This is normally used by the GlyphPainter to determine what characters it should render glyphs for.

 public  void insertUpdate(DocumentEvent e,
    Shape a,
    ViewFactory f) 
{
        justificationInfo = null;
        breakSpots = null;
        minimumSpan = -1;
        syncCR();
        preferenceChanged(null, true, false);
}

Gives notification that something was inserted into the document in a location that this view is responsible for. This is implemented to call preferenceChanged along the axis the glyphs are rendered.

 public boolean isStrikeThrough() 
{
        AttributeSet attr = getAttributes();
        return StyleConstants.isStrikeThrough(attr);
}

Determine if the glyphs should have a strikethrough line. If true, a line should be drawn through the center of the glyphs.

 public boolean isSubscript() 
{
        AttributeSet attr = getAttributes();
        return StyleConstants.isSubscript(attr);
}

Determine if the glyphs should be rendered as superscript.

 public boolean isSuperscript() 
{
        AttributeSet attr = getAttributes();
        return StyleConstants.isSuperscript(attr);
}

Determine if the glyphs should be rendered as subscript.

 public boolean isUnderline() 
{
        AttributeSet attr = getAttributes();
        return StyleConstants.isUnderline(attr);
}

Determine if the glyphs should be underlined. If true, an underline should be drawn through the baseline.

 public Shape modelToView(int pos,
    Shape a,
    Bias b) throws BadLocationException 
{
        checkPainter();
        return painter.modelToView(this, pos, b, a);
}

Provides a mapping from the document model coordinate space to the coordinate space of the view mapped to it.

 public  void paint(Graphics g,
    Shape a) 
{
        checkPainter();
        boolean paintedText = false;
        Component c = getContainer();
        int p0 = getStartOffset();
        int p1 = getEndOffset();
        Rectangle alloc = (a instanceof Rectangle) ? (Rectangle)a : a.getBounds();
        Color bg = getBackground();
        Color fg = getForeground();
        if (c != null && ! c.isEnabled()) {
            fg = (c instanceof JTextComponent ?
                ((JTextComponent)c).getDisabledTextColor() :
                UIManager.getColor("textInactiveText"));
        }
        if (bg != null) {
            g.setColor(bg);
            g.fillRect(alloc.x, alloc.y, alloc.width, alloc.height);
        }
        if (c instanceof JTextComponent) {
            JTextComponent tc = (JTextComponent) c;
            Highlighter h = tc.getHighlighter();
            if (h instanceof LayeredHighlighter) {
                ((LayeredHighlighter)h).paintLayeredHighlights
                    (g, p0, p1, a, tc, this);
            }
        }
        if (Utilities.isComposedTextElement(getElement())) {
            Utilities.paintComposedText(g, a.getBounds(), this);
            paintedText = true;
        } else if(c instanceof JTextComponent) {
            JTextComponent tc = (JTextComponent) c;
            Color selFG = tc.getSelectedTextColor();
            if (// there's a highlighter (bug 4532590), and
                (tc.getHighlighter() != null) &&
                // selected text color is different from regular foreground
                (selFG != null) && !selFG.equals(fg)) {
                Highlighter.Highlight[] h = tc.getHighlighter().getHighlights();
                if(h.length != 0) {
                    boolean initialized = false;
                    int viewSelectionCount = 0;
                    for (int i = 0; i <  h.length; i++) {
                        Highlighter.Highlight highlight = h[i];
                        int hStart = highlight.getStartOffset();
                        int hEnd = highlight.getEndOffset();
                        if (hStart  > p1 || hEnd <  p0) {
                            // the selection is out of this view
                            continue;
                        }
                        if (!SwingUtilities2.useSelectedTextColor(highlight, tc)) {
                            continue;
                        }
                        if (hStart < = p0 && hEnd  >= p1){
                            // the whole view is selected
                            paintTextUsingColor(g, a, selFG, p0, p1);
                            paintedText = true;
                            break;
                        }
                        // the array is lazily created only when the view
                        // is partially selected
                        if (!initialized) {
                            initSelections(p0, p1);
                            initialized = true;
                        }
                        hStart = Math.max(p0, hStart);
                        hEnd = Math.min(p1, hEnd);
                        paintTextUsingColor(g, a, selFG, hStart, hEnd);
                        // the array represents view positions [0, p1-p0+1]
                        // later will iterate this array and sum its
                        // elements. Positions with sum == 0 are not selected.
                        selections[hStart-p0]++;
                        selections[hEnd-p0]--;
                        viewSelectionCount++;
                    }
                    if (!paintedText && viewSelectionCount  > 0) {
                        // the view is partially selected
                        int curPos = -1;
                        int startPos = 0;
                        int viewLen = p1 - p0;
                        while (curPos++ <  viewLen) {
                            // searching for the next selection start
                            while(curPos <  viewLen &&
                                    selections[curPos] == 0) curPos++;
                            if (startPos != curPos) {
                                // paint unselected text
                                paintTextUsingColor(g, a, fg,
                                        p0 + startPos, p0 + curPos);
                            }
                            int checkSum = 0;
                            // searching for next start position of unselected text
                            while (curPos <  viewLen &&
                                    (checkSum += selections[curPos]) != 0) curPos++;
                            startPos = curPos;
                        }
                        paintedText = true;
                    }
                }
            }
        }
        if(!paintedText)
            paintTextUsingColor(g, a, fg, p0, p1);
}

Renders a portion of a text style run.

 final  void paintTextUsingColor(Graphics g,
    Shape a,
    Color c,
    int p0,
    int p1) 
{
        // render the glyphs
        g.setColor(c);
        painter.paint(this, g, a, p0, p1);
        // render underline or strikethrough if set.
        boolean underline = isUnderline();
        boolean strike = isStrikeThrough();
        if (underline || strike) {
            // calculate x coordinates
            Rectangle alloc = (a instanceof Rectangle) ? (Rectangle)a : a.getBounds();
            View parent = getParent();
            if ((parent != null) && (parent.getEndOffset() == p1)) {
                // strip whitespace on end
                Segment s = getText(p0, p1);
                while (Character.isWhitespace(s.last())) {
                    p1 -= 1;
                    s.count -= 1;
                }
                SegmentCache.releaseSharedSegment(s);
            }
            int x0 = alloc.x;
            int p = getStartOffset();
            if (p != p0) {
                x0 += (int) painter.getSpan(this, p, p0, getTabExpander(), x0);
            }
            int x1 = x0 + (int) painter.getSpan(this, p0, p1, getTabExpander(), x0);
            // calculate y coordinate
            int y = alloc.y + alloc.height - (int) painter.getDescent(this);
            if (underline) {
                int yTmp = y + 1;
                g.drawLine(x0, yTmp, x1, yTmp);
            }
            if (strike) {
                // move y coordinate above baseline
                int yTmp = y - (int) (painter.getAscent(this) * 0.3f);
                g.drawLine(x0, yTmp, x1, yTmp);
            }
        }
}

Paints the specified region of text in the specified color.

 public  void removeUpdate(DocumentEvent e,
    Shape a,
    ViewFactory f) 
{
        justificationInfo = null;
        breakSpots = null;
        minimumSpan = -1;
        syncCR();
        preferenceChanged(null, true, false);
}

Gives notification that something was removed from the document in a location that this view is responsible for. This is implemented to call preferenceChanged along the axis the glyphs are rendered.

 public  void setGlyphPainter(GlyphPainter p) 
{
        painter = p;
}

Sets the painter to use for rendering glyphs.

 public int viewToModel(float x,
    float y,
    Shape a,
    Bias[] biasReturn) 
{
        checkPainter();
        return painter.viewToModel(this, x, y, a, biasReturn);
}

Provides a mapping from the view coordinate space to the logical coordinate space of the model.