1/*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.  Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26
27/*
28 *
29 * (C) Copyright IBM Corp. 1998-2004 - All Rights Reserved
30 *
31 */
32
33#ifndef __GXLAYOUTENGINE_H
34#define __GXLAYOUTENGINE_H
35
36#include "LETypes.h"
37#include "LayoutEngine.h"
38
39#include "MorphTables.h"
40
41U_NAMESPACE_BEGIN
42
43class LEFontInstance;
44class LEGlyphStorage;
45
46/**
47 * This class implements layout for QuickDraw GX or Apple Advanced Typograyph (AAT)
48 * fonts. A font is a GX or AAT font if it contains a 'mort' table. See Apple's
49 * TrueType Reference Manual (http://fonts.apple.com/TTRefMan/index.html) for details.
50 * Information about 'mort' tables is in the chapter titled "Font Files."
51 *
52 * @internal
53 */
54class GXLayoutEngine : public LayoutEngine
55{
56public:
57    /**
58     * This is the main constructor. It constructs an instance of GXLayoutEngine for
59     * a particular font, script and language. It takes the 'mort' table as a parameter since
60     * LayoutEngine::layoutEngineFactory has to read the 'mort' table to know that it has a
61     * GX font.
62     *
63     * Note: GX and AAT fonts don't contain any script and language specific tables, so
64     * the script and language are ignored.
65     *
66     * @param fontInstance - the font
67     * @param scriptCode - the script
68     * @param langaugeCode - the language
69     * @param morphTable - the 'mort' table
70     * @param success - set to an error code if the operation fails
71     *
72     * @see LayoutEngine::layoutEngineFactory
73     * @see ScriptAndLangaugeTags.h for script and language codes
74     *
75     * @internal
76     */
77    GXLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode, const LEReferenceTo<MorphTableHeader> &morphTable, LEErrorCode &success);
78
79    /**
80     * The destructor, virtual for correct polymorphic invocation.
81     *
82     * @internal
83     */
84    virtual ~GXLayoutEngine();
85
86    /**
87     * ICU "poor man's RTTI", returns a UClassID for the actual class.
88     *
89     * @stable ICU 2.8
90     */
91    virtual UClassID getDynamicClassID() const;
92
93    /**
94     * ICU "poor man's RTTI", returns a UClassID for this class.
95     *
96     * @stable ICU 2.8
97     */
98    static UClassID getStaticClassID();
99
100protected:
101
102    /**
103     * The address of the 'mort' table
104     *
105     * @internal
106     */
107    LEReferenceTo<MorphTableHeader> fMorphTable;
108
109    /**
110     * This method does GX layout using the font's 'mort' table. It converts the
111     * input character codes to glyph indices using mapCharsToGlyphs, and then
112     * applies the 'mort' table.
113     *
114     * Input parameters:
115     * @param chars - the input character context
116     * @param offset - the index of the first character to process
117     * @param count - the number of characters to process
118     * @param max - the number of characters in the input context
119     * @param rightToLeft - <code>TRUE</code> if the text is in a right to left directional run
120     * @param glyphStorage - the glyph storage object. The glyph and char index arrays will be set.
121     *
122     * Output parameters:
123     * @param success - set to an error code if the operation fails
124     *
125     * @return the number of glyphs in the glyph index array
126     *
127     * @internal
128     */
129    virtual le_int32 computeGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,
130        LEGlyphStorage &glyphStorage, LEErrorCode &success);
131
132    /**
133     * This method adjusts the glyph positions using the font's
134     * 'kern', 'trak', 'bsln', 'opbd' and 'just' tables.
135     *
136     * Input parameters:
137     * @param glyphStorage - the object holding the glyph storage. The positions will be updated as needed.
138     *
139     * Output parameters:
140     * @param success - set to an error code if the operation fails
141     *
142     * @internal
143     */
144    virtual void adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse,
145                                      LEGlyphStorage &glyphStorage, LEErrorCode &success);
146
147};
148
149U_NAMESPACE_END
150#endif
151
152