File	Doc	Category	Size	Date	Package
GlyphView.java	API Doc	Java SE 5 API	41026	Fri Aug 26 14:58:16 BST 2005	javax.swing.text

GlyphView

• java.lang.Object
  • javax.swing.text.View

Fields Summary
private byte[]	selections Used by paint() to store highlighted view positions
int	offset
int	length
boolean	impliedCR
private static final String	IMPLIED_CR
boolean	skipWidth
TabExpander	expander how to expand tabs
int	x location for determining tab expansion against.
GlyphPainter	painter Glyph rendering functionality.
static GlyphPainter	defaultPainter The prototype painter used by default.

Constructors Summary

public GlyphView(Element elem) Constructs a new view wrapped on an element. param elem the element 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");

Methods Summary
public javax.swing.text.View	breakView(int axis, int p0, float pos, float len) 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. param axis may be either View.X_AXIS or View.Y_AXIS param p0 the location in the model where the fragment should start it's representation >= 0. param pos the position along the axis that the broken view would occupy >= 0. This may be useful for things like tab calculations. param len specifies the distance along the axis where a potential break is desired >= 0. return the fragment of the view that represents the given span, if the view can be broken. If the view doesn't support breaking behavior, the view itself is returned. see View#breakView 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;
public void	changedUpdate(javax.swing.event.DocumentEvent e, java.awt.Shape a, javax.swing.text.ViewFactory f) 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. param e the change information from the associated document param a the current allocation of the view param f the factory to use to rebuild if the view has children see View#changedUpdate syncCR(); preferenceChanged(null, true, true);
protected void	checkPainter() Check to see that a glyph painter exists. If a painter doesn't exist, a default glyph painter will be installed. 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())); }
protected final java.lang.Object	clone() Creates a shallow copy. This is used by the createFragment and breakView methods. return the copy Object o; try { o = super.clone(); } catch (CloneNotSupportedException cnse) { o = null; } return o;
public javax.swing.text.View	createFragment(int p0, int p1) 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. param p0 the starting offset >= 0. This should be a value greater or equal to the element starting offset and less than the element ending offset. param p1 the ending offset > p0. This should be a value less than or equal to the elements end offset and greater than the elements starting offset. return the view fragment, or itself if the view doesn't support breaking into fragments see LabelView checkPainter(); Element elem = getElement(); GlyphView v = (GlyphView) clone(); v.offset = p0 - elem.getStartOffset(); v.length = p1 - p0; v.painter = painter.getPainter(v, p0, p1); return v;
public float	getAlignment(int 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. param axis may be either View.X_AXIS or View.Y_AXIS return the desired alignment. This should be a value between 0.0 and 1.0 inclusive, where 0 indicates alignment at the origin and 1.0 indicates alignment to the full span away from the origin. An alignment of 0.5 would be the center of the view. 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);
public java.awt.Color	getBackground() 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. Document doc = getDocument(); if (doc instanceof StyledDocument) { AttributeSet attr = getAttributes(); if (attr.isDefined(StyleConstants.Background)) { return ((StyledDocument)doc).getBackground(attr); } } return null;
private int	getBreakSpot(int p0, int p1) Returns a location to break at in the passed in region, or -1 if there isn't a good location to break at in the specified region. Document doc = getDocument(); if (doc != null && Boolean.TRUE.equals(doc.getProperty( AbstractDocument.MultiByteProperty))) { return getBreakSpotUseBreakIterator(p0, p1); } return getBreakSpotUseWhitespace(p0, p1);
private int	getBreakSpotUseBreakIterator(int p0, int p1) Returns the appropriate place to break based on BreakIterator. // Certain regions require context for BreakIterator, start from // our parents start offset. Element parent = getElement().getParentElement(); int parent0; int parent1; Container c = getContainer(); BreakIterator breaker; if (parent == null) { parent0 = p0; parent1 = p1; } else { parent0 = parent.getStartOffset(); parent1 = parent.getEndOffset(); } if (c != null) { breaker = BreakIterator.getLineInstance(c.getLocale()); } else { breaker = BreakIterator.getLineInstance(); } Segment s = getText(parent0, parent1); int breakPoint; // Needed to initialize the Segment. s.first(); breaker.setText(s); if (p1 == parent1) { // This will most likely return the end, the assumption is // that if parent1 == p1, then we are the last portion of // a paragraph breakPoint = breaker.last(); } else if (p1 + 1 == parent1) { // assert(s.count > 1) breakPoint = breaker.next(s.offset + s.count - 2); if (breakPoint >= s.count + s.offset) { breakPoint = breaker.preceding(s.offset + s.count - 1); } } else { breakPoint = breaker.preceding(p1 - parent0 + s.offset + 1); } int retValue = -1; if (breakPoint != BreakIterator.DONE) { breakPoint = breakPoint - s.offset + parent0; if (breakPoint > p0) { if (p0 == parent0 && breakPoint == p0) { retValue = -1; } else if (breakPoint <= p1) { retValue = breakPoint; } } } SegmentCache.releaseSharedSegment(s); return retValue;
private int	getBreakSpotUseWhitespace(int p0, int p1) Returns the appropriate place to break based on the last whitespace character encountered. Segment s = getText(p0, p1); for (char ch = s.last(); ch != Segment.DONE; ch = s.previous()) { if (Character.isWhitespace(ch)) { // found whitespace SegmentCache.releaseSharedSegment(s); return s.getIndex() - s.getBeginIndex() + 1 + p0; } } SegmentCache.releaseSharedSegment(s); return -1;
public int	getBreakWeight(int axis, float pos, float 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. param axis may be either View.X_AXIS or View.Y_AXIS param pos the potential location of the start of the broken view >= 0. This may be useful for calculating tab positions. param len specifies the relative length from pos where a potential break is desired >= 0. return the weight, which should be a value between View.ForcedBreakWeight and View.BadBreakWeight. see LabelView see ParagraphView see View#BadBreakWeight see View#GoodBreakWeight see View#ExcellentBreakWeight see View#ForcedBreakWeight if (axis == View.X_AXIS) { checkPainter(); int p0 = getStartOffset(); int p1 = painter.getBoundedPosition(this, p0, pos, len); if (p1 == p0) { // can't even fit a single character return View.BadBreakWeight; } if (getBreakSpot(p0, p1) != -1) { return View.ExcellentBreakWeight; } // Nothing good to break on. return View.GoodBreakWeight; } return super.getBreakWeight(axis, pos, len);
public int	getEndOffset() Fetches the portion of the model that this view is responsible for. return the ending offset into the model see View#getEndOffset Element e = getElement(); return (length > 0) ? e.getStartOffset() + offset + length : e.getEndOffset();
public java.awt.Font	getFont() 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. 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;
public java.awt.Color	getForeground() 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. 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;
public javax.swing.text.GlyphView$GlyphPainter	getGlyphPainter() Fetch the currently installed glyph painter. If a painter has not yet been installed, and a default was not yet needed, null is returned. return painter;
public int	getNextVisualPositionFrom(int pos, javax.swing.text.Position$Bias b, java.awt.Shape a, int direction, javax.swing.text.Position$Bias[] 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. param pos the position to convert >= 0 param a the allocated region to render into param direction the direction from the current position that can be thought of as the arrow keys typically found on a keyboard. This may be SwingConstants.WEST, SwingConstants.EAST, SwingConstants.NORTH, or SwingConstants.SOUTH. return the location within the model that best represents the next location visual position. exception BadLocationException exception IllegalArgumentException for an invalid direction return painter.getNextVisualPositionFrom(this, pos, b, a, direction, biasRet);
public float	getPartialSpan(int p0, int p1) 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. param p0 the starting document offset >= 0 param p1 the ending document offset >= p0 return the span >= 0 checkPainter(); float width = painter.getSpan(this, p0, p1, expander, x); return width;
public float	getPreferredSpan(int axis) Determines the preferred span for this view along an axis. param axis may be either View.X_AXIS or View.Y_AXIS return the span the view would like to be rendered into >= 0. Typically the view is told to render into the span that is returned, although there is no guarantee. The parent may choose to resize or break the view. 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); }
public int	getStartOffset() Fetches the portion of the model that this view is responsible for. return the starting offset into the model see View#getStartOffset Element e = getElement(); return (length > 0) ? e.getStartOffset() + offset : e.getStartOffset();
public javax.swing.text.TabExpander	getTabExpander() Fetch the TabExpander to use if tabs are present in this view. return expander;
public float	getTabbedSpan(float x, javax.swing.text.TabExpander e) Determines the desired span when using the given tab expansion implementation. param x the position the view would be located at for the purpose of tab expansion >= 0. param e how to expand the tabs when encountered. return the desired span >= 0 see TabableView#getTabbedSpan 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;
public javax.swing.text.Segment	getText(int p0, int p1) 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. param p0 the starting document offset >= 0 param p1 the ending document offset >= p0 return the Segment containing the text // 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;
private void	initSelections(int p0, int p1) Lazily initializes the selections field int viewPosCount = p1 - p0 + 1; if (selections == null || viewPosCount > selections.length) { selections = new byte[viewPosCount]; return; } for (int i = 0; i < viewPosCount; selections[i++] = 0);
public void	insertUpdate(javax.swing.event.DocumentEvent e, java.awt.Shape a, javax.swing.text.ViewFactory f) 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. param e the change information from the associated document param a the current allocation of the view param f the factory to use to rebuild if the view has children see View#insertUpdate syncCR(); preferenceChanged(null, true, false);
public boolean	isStrikeThrough() Determine if the glyphs should have a strikethrough line. If true, a line should be drawn through the center of the glyphs. AttributeSet attr = getAttributes(); return StyleConstants.isStrikeThrough(attr);
public boolean	isSubscript() Determine if the glyphs should be rendered as superscript. AttributeSet attr = getAttributes(); return StyleConstants.isSubscript(attr);
public boolean	isSuperscript() Determine if the glyphs should be rendered as subscript. AttributeSet attr = getAttributes(); return StyleConstants.isSuperscript(attr);
public boolean	isUnderline() Determine if the glyphs should be underlined. If true, an underline should be drawn through the baseline. AttributeSet attr = getAttributes(); return StyleConstants.isUnderline(attr);
public java.awt.Shape	modelToView(int pos, java.awt.Shape a, javax.swing.text.Position$Bias b) Provides a mapping from the document model coordinate space to the coordinate space of the view mapped to it. param pos the position to convert >= 0 param a the allocated region to render into param b either Position.Bias.Forward or Position.Bias.Backward return the bounding box of the given position exception BadLocationException if the given position does not represent a valid location in the associated document see View#modelToView checkPainter(); return painter.modelToView(this, pos, b, a);
public void	paint(java.awt.Graphics g, java.awt.Shape a) Renders a portion of a text style run. param g the rendering surface to use param a the allocated region to render into 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 instanceof JTextComponent) { JTextComponent tc = (JTextComponent) c; if (!tc.isEnabled()) { fg = tc.getDisabledTextColor(); } } 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);
final void	paintTextUsingColor(java.awt.Graphics g, java.awt.Shape a, java.awt.Color c, int p0, int p1) Paints the specified region of text in the specified color. // 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 ((s.count > 0) && (Character.isWhitespace(s.array[s.count-1]))) { 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 d = (int) painter.getDescent(this); int y = alloc.y + alloc.height - (int) painter.getDescent(this); if (underline) { int yTmp = y; yTmp += 1; g.drawLine(x0, yTmp, x1, yTmp); } if (strike) { int yTmp = y; // move y coordinate above baseline yTmp -= (int) (painter.getAscent(this) * 0.3f); g.drawLine(x0, yTmp, x1, yTmp); } }
public void	removeUpdate(javax.swing.event.DocumentEvent e, java.awt.Shape a, javax.swing.text.ViewFactory f) 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. param e the change information from the associated document param a the current allocation of the view param f the factory to use to rebuild if the view has children see View#removeUpdate syncCR(); preferenceChanged(null, true, false);
public void	setGlyphPainter(javax.swing.text.GlyphView$GlyphPainter p) Sets the painter to use for rendering glyphs. painter = p;
private void	syncCR() if (impliedCR) { Element parent = getElement().getParentElement(); impliedCR = (parent != null && parent.getElementCount() > 1); }
public int	viewToModel(float x, float y, java.awt.Shape a, javax.swing.text.Position$Bias[] biasReturn) Provides a mapping from the view coordinate space to the logical coordinate space of the model. param x the X coordinate >= 0 param y the Y coordinate >= 0 param a the allocated region to render into param biasReturn either Position.Bias.Forward or Position.Bias.Backward is returned as the zero-th element of this array return the location within the model that best represents the given point of view >= 0 see View#viewToModel checkPainter(); return painter.viewToModel(this, x, y, a, biasReturn);