The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2006 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 android.text; |
| 18 | |
| 19 | /** |
| 20 | * Abstract class for filtering login-related text (user names and passwords) |
| 21 | * |
| 22 | */ |
| 23 | public abstract class LoginFilter implements InputFilter { |
| 24 | private boolean mAppendInvalid; // whether to append or ignore invalid characters |
| 25 | /** |
| 26 | * Base constructor for LoginFilter |
| 27 | * @param appendInvalid whether or not to append invalid characters. |
| 28 | */ |
| 29 | LoginFilter(boolean appendInvalid) { |
| 30 | mAppendInvalid = appendInvalid; |
| 31 | } |
| 32 | |
| 33 | /** |
| 34 | * Default constructor for LoginFilter doesn't append invalid characters. |
| 35 | */ |
| 36 | LoginFilter() { |
| 37 | mAppendInvalid = false; |
| 38 | } |
| 39 | |
| 40 | /** |
| 41 | * This method is called when the buffer is going to replace the |
| 42 | * range <code>dstart … dend</code> of <code>dest</code> |
| 43 | * with the new text from the range <code>start … end</code> |
| 44 | * of <code>source</code>. Returns the CharSequence that we want |
| 45 | * placed there instead, including an empty string |
| 46 | * if appropriate, or <code>null</code> to accept the original |
| 47 | * replacement. Be careful to not to reject 0-length replacements, |
| 48 | * as this is what happens when you delete text. |
| 49 | */ |
| 50 | public CharSequence filter(CharSequence source, int start, int end, |
| 51 | Spanned dest, int dstart, int dend) { |
| 52 | char[] out = new char[end - start]; // reserve enough space for whole string |
| 53 | int outidx = 0; |
| 54 | boolean changed = false; |
| 55 | |
| 56 | onStart(); |
| 57 | |
| 58 | // Scan through beginning characters in dest, calling onInvalidCharacter() |
| 59 | // for each invalid character. |
| 60 | for (int i = 0; i < dstart; i++) { |
| 61 | char c = dest.charAt(i); |
| 62 | if (!isAllowed(c)) onInvalidCharacter(c); |
| 63 | } |
| 64 | |
| 65 | // Scan through changed characters rejecting disallowed chars |
| 66 | for (int i = start; i < end; i++) { |
| 67 | char c = source.charAt(i); |
| 68 | if (isAllowed(c)) { |
| 69 | // Character allowed. Add it to the sequence. |
| 70 | out[outidx++] = c; |
| 71 | } else { |
| 72 | if (mAppendInvalid) out[outidx++] = c; |
| 73 | else changed = true; // we changed the original string |
| 74 | onInvalidCharacter(c); |
| 75 | } |
| 76 | } |
| 77 | |
| 78 | // Scan through remaining characters in dest, calling onInvalidCharacter() |
| 79 | // for each invalid character. |
| 80 | for (int i = dend; i < dest.length(); i++) { |
| 81 | char c = dest.charAt(i); |
| 82 | if (!isAllowed(c)) onInvalidCharacter(c); |
| 83 | } |
| 84 | |
| 85 | onStop(); |
| 86 | |
| 87 | if (!changed) { |
| 88 | return null; |
| 89 | } |
| 90 | |
| 91 | String s = new String(out, 0, outidx); |
| 92 | |
| 93 | if (source instanceof Spanned) { |
| 94 | SpannableString sp = new SpannableString(s); |
| 95 | TextUtils.copySpansFrom((Spanned) source, |
| 96 | start, end, null, sp, 0); |
| 97 | return sp; |
| 98 | } else { |
| 99 | return s; |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | /** |
| 104 | * Called when we start processing filter. |
| 105 | */ |
| 106 | public void onStart() { |
| 107 | |
| 108 | } |
| 109 | |
| 110 | /** |
| 111 | * Called whenever we encounter an invalid character. |
| 112 | * @param c the invalid character |
| 113 | */ |
| 114 | public void onInvalidCharacter(char c) { |
| 115 | |
| 116 | } |
| 117 | |
| 118 | /** |
| 119 | * Called when we're done processing filter |
| 120 | */ |
| 121 | public void onStop() { |
| 122 | |
| 123 | } |
| 124 | |
| 125 | /** |
| 126 | * Returns whether or not we allow character c. |
| 127 | * Subclasses must override this method. |
| 128 | */ |
| 129 | public abstract boolean isAllowed(char c); |
| 130 | |
| 131 | /** |
| 132 | * This filter rejects characters in the user name that are not compatible with GMail |
| 133 | * account creation. It prevents the user from entering user names with characters other than |
| 134 | * [a-zA-Z0-9.]. |
| 135 | * |
| 136 | */ |
| 137 | public static class UsernameFilterGMail extends LoginFilter { |
| 138 | |
| 139 | public UsernameFilterGMail() { |
| 140 | super(false); |
| 141 | } |
| 142 | |
| 143 | public UsernameFilterGMail(boolean appendInvalid) { |
| 144 | super(appendInvalid); |
| 145 | } |
| 146 | |
| 147 | @Override |
| 148 | public boolean isAllowed(char c) { |
| 149 | // Allow [a-zA-Z0-9@.] |
| 150 | if ('0' <= c && c <= '9') |
| 151 | return true; |
| 152 | if ('a' <= c && c <= 'z') |
| 153 | return true; |
| 154 | if ('A' <= c && c <= 'Z') |
| 155 | return true; |
| 156 | if ('.' == c) |
| 157 | return true; |
| 158 | return false; |
| 159 | } |
| 160 | } |
| 161 | |
| 162 | /** |
| 163 | * This filter rejects characters in the user name that are not compatible with Google login. |
| 164 | * It is slightly less restrictive than the above filter in that it allows [a-zA-Z0-9._-]. |
| 165 | * |
| 166 | */ |
| 167 | public static class UsernameFilterGeneric extends LoginFilter { |
| 168 | private static final String mAllowed = "@_-."; // Additional characters |
| 169 | |
| 170 | public UsernameFilterGeneric() { |
| 171 | super(false); |
| 172 | } |
| 173 | |
| 174 | public UsernameFilterGeneric(boolean appendInvalid) { |
| 175 | super(appendInvalid); |
| 176 | } |
| 177 | |
| 178 | @Override |
| 179 | public boolean isAllowed(char c) { |
| 180 | // Allow [a-zA-Z0-9@.] |
| 181 | if ('0' <= c && c <= '9') |
| 182 | return true; |
| 183 | if ('a' <= c && c <= 'z') |
| 184 | return true; |
| 185 | if ('A' <= c && c <= 'Z') |
| 186 | return true; |
| 187 | if (mAllowed.indexOf(c) != -1) |
| 188 | return true; |
| 189 | return false; |
| 190 | } |
| 191 | } |
| 192 | |
| 193 | /** |
| 194 | * This filter is compatible with GMail passwords which restricts characters to |
| 195 | * the Latin-1 (ISO8859-1) char set. |
| 196 | * |
| 197 | */ |
| 198 | public static class PasswordFilterGMail extends LoginFilter { |
| 199 | |
| 200 | public PasswordFilterGMail() { |
| 201 | super(false); |
| 202 | } |
| 203 | |
| 204 | public PasswordFilterGMail(boolean appendInvalid) { |
| 205 | super(appendInvalid); |
| 206 | } |
| 207 | |
| 208 | // We should reject anything not in the Latin-1 (ISO8859-1) charset |
| 209 | @Override |
| 210 | public boolean isAllowed(char c) { |
| 211 | if (32 <= c && c <= 127) |
| 212 | return true; // standard charset |
| 213 | // if (128 <= c && c <= 159) return true; // nonstandard (Windows(TM)(R)) charset |
| 214 | if (160 <= c && c <= 255) |
| 215 | return true; // extended charset |
| 216 | return false; |
| 217 | } |
| 218 | } |
| 219 | } |