1/*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.inputmethod.keyboard.internal;
18
19import com.android.inputmethod.latin.common.Constants;
20import com.android.inputmethod.latin.common.StringUtils;
21
22import android.text.TextUtils;
23
24/**
25 * The string parser of codesArray specification for <GridRows />. The attribute codesArray is an
26 * array of string.
27 * Each element of the array defines a key label by specifying a code point as a hexadecimal string.
28 * A key label may consist of multiple code points separated by comma.
29 * Each element of the array optionally can have an output text definition after vertical bar
30 * marker. An output text may consist of multiple code points separated by comma.
31 * The format of the codesArray element should be:
32 * <pre>
33 *   label1[,label2]*(|outputText1[,outputText2]*(|minSupportSdkVersion)?)?
34 * </pre>
35 */
36// TODO: Write unit tests for this class.
37public final class CodesArrayParser {
38    // Constants for parsing.
39    private static final char COMMA = Constants.CODE_COMMA;
40    private static final String COMMA_REGEX = StringUtils.newSingleCodePointString(COMMA);
41    private static final String VERTICAL_BAR_REGEX = // "\\|"
42            new String(new char[] { Constants.CODE_BACKSLASH, Constants.CODE_VERTICAL_BAR });
43    private static final int BASE_HEX = 16;
44
45    private CodesArrayParser() {
46     // This utility class is not publicly instantiable.
47    }
48
49    private static String getLabelSpec(final String codesArraySpec) {
50        final String[] strs = codesArraySpec.split(VERTICAL_BAR_REGEX, -1);
51        if (strs.length <= 1) {
52            return codesArraySpec;
53        }
54        return strs[0];
55    }
56
57    public static String parseLabel(final String codesArraySpec) {
58        final String labelSpec = getLabelSpec(codesArraySpec);
59        final StringBuilder sb = new StringBuilder();
60        for (final String codeInHex : labelSpec.split(COMMA_REGEX)) {
61            final int codePoint = Integer.parseInt(codeInHex, BASE_HEX);
62            sb.appendCodePoint(codePoint);
63        }
64        return sb.toString();
65    }
66
67    private static String getCodeSpec(final String codesArraySpec) {
68        final String[] strs = codesArraySpec.split(VERTICAL_BAR_REGEX, -1);
69        if (strs.length <= 1) {
70            return codesArraySpec;
71        }
72        return TextUtils.isEmpty(strs[1]) ? strs[0] : strs[1];
73    }
74
75    public static int getMinSupportSdkVersion(final String codesArraySpec) {
76        final String[] strs = codesArraySpec.split(VERTICAL_BAR_REGEX, -1);
77        if (strs.length <= 2) {
78            return 0;
79        }
80        try {
81            return Integer.parseInt(strs[2]);
82        } catch (NumberFormatException e) {
83            return 0;
84        }
85    }
86
87    public static int parseCode(final String codesArraySpec) {
88        final String codeSpec = getCodeSpec(codesArraySpec);
89        if (codeSpec.indexOf(COMMA) < 0) {
90            return Integer.parseInt(codeSpec, BASE_HEX);
91        }
92        return Constants.CODE_OUTPUT_TEXT;
93    }
94
95    public static String parseOutputText(final String codesArraySpec) {
96        final String codeSpec = getCodeSpec(codesArraySpec);
97        if (codeSpec.indexOf(COMMA) < 0) {
98            return null;
99        }
100        final StringBuilder sb = new StringBuilder();
101        for (final String codeInHex : codeSpec.split(COMMA_REGEX)) {
102            final int codePoint = Integer.parseInt(codeInHex, BASE_HEX);
103            sb.appendCodePoint(codePoint);
104        }
105        return sb.toString();
106    }
107}
108