1 /*
2  * Copyright (C) 2016 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.dialer.smartdial.map;
18 
19 import android.support.v4.util.SimpleArrayMap;
20 import com.google.common.base.Optional;
21 
22 /** Definition for utilities that supports smart dial in different languages. */
23 @SuppressWarnings("Guava")
24 abstract class SmartDialMap {
25 
26   /**
27    * Returns true if the provided character can be mapped to a key on the dialpad.
28    *
29    * <p>The provided character is expected to be a normalized character. See {@link
30    * SmartDialMap#normalizeCharacter(char)} for details.
31    */
isValidDialpadCharacter(char ch)32   protected boolean isValidDialpadCharacter(char ch) {
33     return isValidDialpadAlphabeticChar(ch) || isValidDialpadNumericChar(ch);
34   }
35 
36   /**
37    * Returns true if the provided character is a letter and can be mapped to a key on the dialpad.
38    *
39    * <p>The provided character is expected to be a normalized character. See {@link
40    * SmartDialMap#normalizeCharacter(char)} for details.
41    */
isValidDialpadAlphabeticChar(char ch)42   protected boolean isValidDialpadAlphabeticChar(char ch) {
43     return getCharToKeyMap().containsKey(ch);
44   }
45 
46   /**
47    * Returns true if the provided character is a digit, and can be mapped to a key on the dialpad.
48    */
isValidDialpadNumericChar(char ch)49   protected boolean isValidDialpadNumericChar(char ch) {
50     return '0' <= ch && ch <= '9';
51   }
52 
53   /**
54    * Get the index of the key on the dialpad which the character corresponds to.
55    *
56    * <p>The provided character is expected to be a normalized character. See {@link
57    * SmartDialMap#normalizeCharacter(char)} for details.
58    *
59    * <p>An {@link Optional#absent()} is returned if the provided character can't be mapped to a key
60    * on the dialpad.
61    */
getDialpadIndex(char ch)62   protected Optional<Byte> getDialpadIndex(char ch) {
63     if (isValidDialpadNumericChar(ch)) {
64       return Optional.of((byte) (ch - '0'));
65     }
66 
67     if (isValidDialpadAlphabeticChar(ch)) {
68       return Optional.of((byte) (getCharToKeyMap().get(ch) - '0'));
69     }
70 
71     return Optional.absent();
72   }
73 
74   /**
75    * Get the actual numeric character on the dialpad which the character corresponds to.
76    *
77    * <p>The provided character is expected to be a normalized character. See {@link
78    * SmartDialMap#normalizeCharacter(char)} for details.
79    *
80    * <p>An {@link Optional#absent()} is returned if the provided character can't be mapped to a key
81    * on the dialpad.
82    */
getDialpadNumericCharacter(char ch)83   protected Optional<Character> getDialpadNumericCharacter(char ch) {
84     return isValidDialpadAlphabeticChar(ch)
85         ? Optional.of(getCharToKeyMap().get(ch))
86         : Optional.absent();
87   }
88 
89   /**
90    * Converts uppercase characters to lower case ones, and on a best effort basis, strips accents
91    * from accented characters.
92    *
93    * <p>An {@link Optional#absent()} is returned if the provided character can't be mapped to a key
94    * on the dialpad.
95    */
normalizeCharacter(char ch)96   abstract Optional<Character> normalizeCharacter(char ch);
97 
98   /**
99    * Returns a map in which each key is a normalized character and the corresponding value is a
100    * dialpad key.
101    */
getCharToKeyMap()102   abstract SimpleArrayMap<Character, Character> getCharToKeyMap();
103 }
104