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	/*
	* Copyright (c) 1999, 2008, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code 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. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code 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 in the LICENSE file that
	* accompanied this code).
	*
	* 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*
	*/

	/*
	* (C) Copyright IBM Corp. 1999, All rights reserved.
	*/

	package sun.font;

	import java.awt.Font;
	import java.awt.GraphicsEnvironment;
	import java.awt.font.TextAttribute;
	import java.util.ArrayList;
	import java.util.Map;
	import sun.text.CodePointIterator;

	/**
	* This class maps an individual character to a Font family which can
	* display it. The character-to-Font mapping does not depend on the
	* character's context, so a particular character will be mapped to the
	* same font family each time.
	* <p>
	* Typically, clients will call getIndexFor(char) for each character
	* in a style run. When getIndexFor() returns a different value from
	* ones seen previously, the characters up to that point will be assigned
	* a font obtained from getFont().
	*/
	public final class FontResolver {

	// An array of all fonts available to the runtime. The fonts
	// will be searched in order.
	private Font[] allFonts;
	private Font[] supplementaryFonts;
	private int[] supplementaryIndices;

	// Default size of Fonts (if created from an empty Map, for instance).
	private static final int DEFAULT_SIZE = 12; // from Font

	private Font defaultFont = new Font(Font.DIALOG, Font.PLAIN, DEFAULT_SIZE);

	// The results of previous lookups are cached in a two-level
	// table. The value for a character c is found in:
	// blocks[c>>SHIFT][c&MASK]
	// although the second array is only allocated when needed.
	// A 0 value means the character's font has not been looked up.
	// A positive value means the character's font is in the allFonts
	// array at index (value-1).
	private static final int SHIFT = 9;
	private static final int BLOCKSIZE = 1<<(16-SHIFT);
	private static final int MASK = BLOCKSIZE-1;
	private int[][] blocks = new int[1<<SHIFT][];

	private FontResolver() {
	}

	private Font[] getAllFonts() {
	if (allFonts == null) {
	allFonts =
	GraphicsEnvironment.getLocalGraphicsEnvironment().getAllFonts();
	for (int i=0; i < allFonts.length; i++) {
	allFonts[i] = allFonts[i].deriveFont((float)DEFAULT_SIZE);
	}
	}
	return allFonts;
	}

	/**
	* Search fonts in order, and return "1" to indicate its in the default
	* font, (or not found at all), or the index of the first font
	* which can display the given character, plus 2, if it is not
	* in the default font.
	*/
	private int getIndexFor(char c) {

	if (defaultFont.canDisplay(c)) {
	return 1;
	}
	for (int i=0; i < getAllFonts().length; i++) {
	if (allFonts[i].canDisplay(c)) {
	return i+2;
	}
	}
	return 1;
	}

	private Font [] getAllSCFonts() {

	if (supplementaryFonts == null) {
	ArrayList<Font> fonts = new ArrayList<Font>();
	ArrayList<Integer> indices = new ArrayList<Integer>();

	for (int i=0; i<getAllFonts().length; i++) {
	Font font = allFonts[i];
	Font2D font2D = FontUtilities.getFont2D(font);
	if (font2D.hasSupplementaryChars()) {
	fonts.add(font);
	indices.add(Integer.valueOf(i));
	}
	}

	int len = fonts.size();
	supplementaryIndices = new int[len];
	for (int i=0; i<len; i++) {
	supplementaryIndices[i] = indices.get(i);
	}
	supplementaryFonts = fonts.toArray(new Font[len]);
	}
	return supplementaryFonts;
	}

	/* This method is called only for character codes >= 0x10000 - which
	* are assumed to be legal supplementary characters.
	* It looks first at the default font (to avoid calling getAllFonts if at
	* all possible) and if that doesn't map the code point, it scans
	* just the fonts that may contain supplementary characters.
	* The index that is returned is into the "allFonts" array so that
	* callers see the same value for both supplementary and base chars.
	*/
	private int getIndexFor(int cp) {

	if (defaultFont.canDisplay(cp)) {
	return 1;
	}

	for (int i = 0; i < getAllSCFonts().length; i++) {
	if (supplementaryFonts[i].canDisplay(cp)) {
	return supplementaryIndices[i]+2;
	}
	}
	return 1;
	}

	/**
	* Return an index for the given character. The index identifies a
	* font family to getFont(), and has no other inherent meaning.
	* @param c the character to map
	* @return a value for consumption by getFont()
	* @see #getFont
	*/
	public int getFontIndex(char c) {

	int blockIndex = c>>SHIFT;
	int[] block = blocks[blockIndex];
	if (block == null) {
	block = new int[BLOCKSIZE];
	blocks[blockIndex] = block;
	}

	int index = c & MASK;
	if (block[index] == 0) {
	block[index] = getIndexFor(c);
	}
	return block[index];
	}

	public int getFontIndex(int cp) {
	if (cp < 0x10000) {
	return getFontIndex((char)cp);
	}
	return getIndexFor(cp);
	}

	/**
	* Determines the font index for the code point at the current position in the
	* iterator, then advances the iterator to the first code point that has
	* a different index or until the iterator is DONE, and returns the font index.
	* @param iter a code point iterator, this will be advanced past any code
	* points that have the same font index
	* @return the font index for the initial code point found, or 1 if the iterator
	* was empty.
	*/
	public int nextFontRunIndex(CodePointIterator iter) {
	int cp = iter.next();
	int fontIndex = 1;
	if (cp != CodePointIterator.DONE) {
	fontIndex = getFontIndex(cp);

	while ((cp = iter.next()) != CodePointIterator.DONE) {
	if (getFontIndex(cp) != fontIndex) {
	iter.prev();
	break;
	}
	}
	}
	return fontIndex;
	}

	/**
	* Return a Font from a given font index with properties
	* from attributes. The font index, which should have been produced
	* by getFontIndex(), determines a font family. The size and style
	* of the Font reflect the properties in attributes. Any Font or
	* font family specifications in attributes are ignored, on the
	* assumption that clients have already handled them.
	* @param index an index from getFontIndex() which determines the
	* font family
	* @param attributes a Map from which the size and style of the Font
	* are determined. The default size is 12 and the default style
	* is Font.PLAIN
	* @see #getFontIndex
	*/
	public Font getFont(int index, Map attributes) {
	Font font = defaultFont;

	if (index >= 2) {
	font = allFonts[index-2];
	}

	return font.deriveFont(attributes);
	}

	private static FontResolver INSTANCE;

	/**
	* Return a shared instance of FontResolver.
	*/
	public static FontResolver getInstance() {
	if (INSTANCE == null) {
	INSTANCE = new FontResolver();
	}
	return INSTANCE;
	}
	}

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