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 
17 package com.android.inputmethod.keyboard.internal;
18 
19 import com.android.inputmethod.latin.Constants;
20 import com.android.inputmethod.latin.utils.StringUtils;
21 
22 import 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.
37 public 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 
CodesArrayParser()45     private CodesArrayParser() {
46      // This utility class is not publicly instantiable.
47     }
48 
getLabelSpec(final String codesArraySpec)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 
parseLabel(final String codesArraySpec)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 
getCodeSpec(final String codesArraySpec)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 
getMinSupportSdkVersion(final String codesArraySpec)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 
parseCode(final String codesArraySpec)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 
parseOutputText(final String codesArraySpec)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