/*
* $RCSfile: Font.java,v $
*
* Copyright 1990-2009 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 only, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License version 2 for more details (a copy is
* included at /legal/license.txt).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this work; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
* Clara, CA 95054 or visit www.sun.com if you need additional
* information or have any questions.
*/
package com.sun.perseus.model;
import com.sun.perseus.j2d.RenderGraphics;
import com.sun.perseus.util.SVGConstants;
import java.util.Vector;
import org.w3c.dom.DOMException;
/**
* A <code>Font</code> node models an SVG <code><code></code>
* element.
*
* @version $Id: Font.java,v 1.7 2006/06/29 10:47:31 ln156897 Exp $
*/
public class Font extends ElementNode {
/**
* Only the horiz-adv-x trait is required on <font>
*/
static final String[] REQUIRED_TRAITS
= {SVGConstants.SVG_HORIZ_ADV_X_ATTRIBUTE};
/**
* The X-coordinate in the font coordinate system of the origin
* of a glyph to be used when drawing horizontally oriented text.
* (Note that the origin applies to all glyphs in the font.)
*/
protected float horizontalOriginX;
/**
* The default horizontal advance after rendering a glyph in
* horizontal orientation. Glyph widths are required to be non-negative,
* even if the glyph is typically rendered right-to-left, as in
* Hebrew and Arabic scripts.
*/
protected float horizontalAdvanceX;
/**
* The current fontFace describing this font, if any
*/
protected FontFace fontFace;
/**
* The Font's missing glyph, used to render unknown characters
*/
protected Glyph missingGlyph;
/**
* The Font's first horizontal kerning pair. May be null.
*/
protected HKern firstHKern;
/**
* The Font's last horizontal kerning pair. May be null.
*/
protected HKern lastHKern;
/**
* Constructor.
*
* @param ownerDocument this element's owner <code>DocumentNode</code>
*/
public Font(final DocumentNode ownerDocument) {
super(ownerDocument);
}
/**
* @return the SVGConstants.SVG_FONT_TAG value
*/
public String getLocalName() {
return SVGConstants.SVG_FONT_TAG;
}
/**
* Used by <code>DocumentNode</code> to create a new instance from
* a prototype <code>Font</code>.
*
* @param doc the <code>DocumentNode</code> for which a new node is
* should be created.
* @return a new <code>Font</code> for the requested document.
*/
public ElementNode newInstance(final DocumentNode doc) {
return new Font(doc);
}
/**
* @param newHorizontalOriginX the new value for the <tt>Font</tt>'s
* origin along the x-axis.
*/
public void setHorizontalOriginX(final float newHorizontalOriginX) {
if (newHorizontalOriginX == horizontalOriginX) {
return;
}
modifyingNode();
horizontalOriginX = newHorizontalOriginX;
modifiedNode();
}
/**
* @return this <tt>Font</tt>'s origin along the x-axis
*/
public float getHorizontalOriginX() {
return horizontalOriginX;
}
/**
* @param newHorizontalAdvanceX the new horizontal advance along the
* x-axis for this <tt>Font</tt>
*/
public void setHorizontalAdvanceX(final float newHorizontalAdvanceX) {
if (newHorizontalAdvanceX == horizontalAdvanceX) {
return;
}
modifyingNode();
horizontalAdvanceX = newHorizontalAdvanceX;
modifiedNode();
}
/**
* @return this <tt>Font</tt>'s horizontal adavance along the x-axis
*/
public float getHorizontalAdvanceX() {
return horizontalAdvanceX;
}
/**
* Returns a Glyph if the FontFace can display the
* character at the requested index. Returns null
* if no matching glyph can be found.
*
* @param s the character sequence to display
* @param index the index of the first character in <tt>s</tt> to
* display.
* @return the <tt>Glyph</tt> used to represent the input
* character at <tt>index</tt> in <tt>s</tt>
*/
public Glyph canDisplay(final char[] s, final int index) {
int max = s.length - index;
int glLength = 0;
int j = 0;
Glyph gl = null;
ModelNode c = firstChild;
while (c != null) {
if (c instanceof Glyph) {
gl = (Glyph) c;
glLength = gl.getLength();
if (gl.getUnicode() != null
&& glLength > 0
&& index + glLength <= s.length) {
for (j = 0; j < glLength; j++) {
if (s[index + j] != gl.getCharAt(j)) {
break;
}
}
if (j == glLength) {
return gl;
}
}
}
c = c.nextSibling;
}
// No matching glyph
return null;
}
/**
* @return the Glyph that represents missing glyphs.
* This should *not* be null.
*/
public Glyph getMissingGlyph() {
return missingGlyph;
}
// ====================================================================
// List Implementation overrides to track special children
// ====================================================================
/**
* @param node <tt>ElementNode</tt> to add to this <tt>ElementNode</tt>
*/
public void add(final ElementNode node) {
super.add(node);
addSpecial(node);
}
/**
* Called in case special handling of children is required.
*
* @param node the <tt>ModelNode</tt> added to this list
*
* @see #addFontFace
* @see #addGlyph
*/
protected void addSpecial(final ModelNode node) {
if (!(node instanceof Glyph)) {
if (!(node instanceof FontFace)) {
if (!(node instanceof HKern)) {
return;
} else {
addHKern((HKern) node);
}
} else {
addFontFace((FontFace) node);
}
} else {
Glyph gl = (Glyph) node;
if (gl.getUnicode() == null) {
addMissingGlyph(gl);
} else {
addGlyph(gl);
}
}
}
/**
* @param newFontFace the <tt>FontFace</tt> child to add
*/
protected void addFontFace(final FontFace newFontFace) {
if (fontFace != null) {
// If there is already a FontFace child, we ignore the second
// one. Only the first child is accounted for.
return;
}
// A Font can only have a single font-face child. If there is alre
fontFace = newFontFace;
updateGlyphEmSquare();
}
/**
* Simply chain the kerning pairs so that they can be
* looked up easily later.
*
* @param hkern the new <code>HKern</code> entry to add
* to this node.
*/
protected void addHKern(final HKern hkern) {
if (firstHKern != null) {
lastHKern.nextHKern = hkern;
lastHKern = hkern;
} else {
firstHKern = hkern;
lastHKern = hkern;
hkern.nextHKern = null;
}
}
/**
* Used by the Text class: looks up kerning pairs to check if
* there is any horizontal kerning for the input pair.
*
* @param g1 this first glyph is assumed to be part of this
* Font.
* @param g2 this second glyph may come from a different font, in
* which case this method returns 0.
* @return the kerning adjustment for the given pair of <code>Glyph</code>s.
*/
float getHKern(final Glyph g1, final Glyph g2) {
if (g2.parent != this) {
return 0;
}
HKern k = firstHKern;
while (k != null) {
if (k.matchesFirst(g1)) {
if (k.matchesSecond(g2)) {
break;
}
}
k = k.nextHKern;
}
if (k != null) {
if (fontFace != null) {
return k.k * fontFace.getEmSquareScale();
} else {
return k.k;
}
} else {
return 0;
}
}
/**
* Update the em square on all the <tt>Font</tt>'s glyphs
*/
protected void updateGlyphEmSquare() {
float emSquareScale = 1;
if (fontFace != null) {
emSquareScale = fontFace.getEmSquareScale();
}
ElementNode c = firstChild;
while (c != null) {
if (c instanceof Glyph) {
((Glyph) c).setEmSquareScale(emSquareScale);
}
c = (ElementNode) c.nextSibling;
}
}
/**
* @param gl set the input <tt>Glyph</tt>'s em square.
*/
protected void updateGlyphEmSquare(final Glyph gl) {
if (fontFace != null) {
gl.setEmSquareScale(fontFace.getEmSquareScale());
} else {
gl.setEmSquareScale(1);
}
}
/**
* If there is already a missing glyph, any new call
* to <tt>addMissingGlyph</tt> has no effect on the
* missing glyph.
*
* @param gl <tt>Glyph</tt> to add as a missing glyph.
*/
protected void addMissingGlyph(final Glyph gl) {
// Only use gl as a missing glyph if it is the
// first missing glyph
if (missingGlyph == null) {
missingGlyph = gl;
}
updateGlyphEmSquare(gl);
}
/**
* @param gl <tt>Glyph</tt> to add to this font
*/
protected void addGlyph(final Glyph gl) {
updateGlyphEmSquare(gl);
}
/**
* Font handlers the horiz-adv-x and horiz-origin-x traits.
*
* @param traitName the name of the trait which the element may support.
* @return true if this element supports the given trait in one of the
* trait accessor methods.
*/
boolean supportsTrait(final String traitName) {
if (SVGConstants.SVG_HORIZ_ORIGIN_X_ATTRIBUTE == traitName
||
SVGConstants.SVG_HORIZ_ADV_X_ATTRIBUTE == traitName) {
return true;
}
return super.supportsTrait(traitName);
}
/**
* @return an array of traits that are required by this element.
*/
public String[] getRequiredTraits() {
return REQUIRED_TRAITS;
}
/**
* Font handles the horiz-adv-x and horiz-origin-x traits.
* Other traits are handled by the super class.
*
* @param name the requested trait name (e.g., "horiz-adv-x")
* @return the trait's value, as a string.
*
* @throws DOMException with error code NOT_SUPPORTED_ERROR if the requested
* trait is not supported on this element or null.
* @throws DOMException with error code TYPE_MISMATCH_ERR if requested
* trait's computed value cannot be converted to a String (SVG Tiny only).
*/
public String getTraitImpl(final String name)
throws DOMException {
if (SVGConstants.SVG_HORIZ_ADV_X_ATTRIBUTE == name) {
return Float.toString(getHorizontalAdvanceX());
} else if (SVGConstants.SVG_HORIZ_ORIGIN_X_ATTRIBUTE == name) {
return Float.toString(getHorizontalOriginX());
} else {
return super.getTraitImpl(name);
}
}
/**
* Font handles the horiz-adv-x and horiz-origin-x traits.
* Other traits are handled by the super class.
*
* @param name the requested trait name (e.g., "horiz-adv-x")
* @return the trait's value, as a float.
*
* @throws DOMException with error code NOT_SUPPORTED_ERROR if the requested
* trait is not supported on this element or null.
* @throws DOMException with error code TYPE_MISMATCH_ERR if requested
* trait's computed value cannot be converted to a String (SVG Tiny only).
*/
float getFloatTraitImpl(final String name)
throws DOMException {
if (SVGConstants.SVG_HORIZ_ADV_X_ATTRIBUTE == name) {
return getHorizontalAdvanceX();
} else if (SVGConstants.SVG_HORIZ_ORIGIN_X_ATTRIBUTE == name) {
return getHorizontalOriginX();
} else {
return super.getFloatTraitImpl(name);
}
}
/**
* Font handles the horiz-adv-x and horiz-origin-x traits.
* Other traits are handled by the super class.
*
* @param name the trait's name (e.g., "horiz-adv-x")
* @param value the new trait string value (e.g., "10")
*
* @throws DOMException with error code NOT_SUPPORTED_ERROR if the requested
* trait is not supported on this element or null.
* @throws DOMException with error code TYPE_MISMATCH_ERR if the requested
* trait's value cannot be specified as a String
* @throws DOMException with error code INVALID_ACCESS_ERR if the input
* value is an invalid value for the given trait or null.
* @throws DOMException with error code NO_MODIFICATION_ALLOWED_ERR: if
* attempt is made to change readonly trait.
*/
public void setTraitImpl(final String name, final String value)
throws DOMException {
if (SVGConstants.SVG_HORIZ_ADV_X_ATTRIBUTE == name) {
checkWriteLoading(name);
setHorizontalAdvanceX(parseFloatTrait(name, value));
} else if (SVGConstants.SVG_HORIZ_ORIGIN_X_ATTRIBUTE == name) {
checkWriteLoading(name);
setHorizontalOriginX(parseFloatTrait(name, value));
} else {
super.setTraitImpl(name, value);
}
}
/**
* Font handles the horiz-adv-x and horiz-origin-x traits.
* Other traits are handled by the super class.
*
* @param name the trait's name (e.g., "horiz-adv-x")
* @param value the new trait float value (e.g., 10f)
*
* @throws DOMException with error code NOT_SUPPORTED_ERROR if the requested
* trait is not supported on this element or null.
* @throws DOMException with error code TYPE_MISMATCH_ERR if the requested
* trait's value cannot be specified as a String
* @throws DOMException with error code INVALID_ACCESS_ERR if the input
* value is an invalid value for the given trait or null.
* @throws DOMException with error code NO_MODIFICATION_ALLOWED_ERR: if
* attempt is made to change readonly trait.
*/
public void setFloatTraitImpl(final String name, final float value)
throws DOMException {
if (SVGConstants.SVG_HORIZ_ADV_X_ATTRIBUTE == name) {
setHorizontalAdvanceX(value);
} else if (SVGConstants.SVG_HORIZ_ORIGIN_X_ATTRIBUTE == name) {
setHorizontalOriginX(value);
} else {
super.setFloatTraitImpl(name, value);
}
}
}