KeySpecParser.java revision c217dc9237e5d1e1e721b9007139d771dcb41145
1/* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not 5 * use this file except in compliance with the License. You may obtain a copy of 6 * 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, WITHOUT 12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 13 * License for the specific language governing permissions and limitations under 14 * the License. 15 */ 16 17package com.android.inputmethod.keyboard.internal; 18 19import android.content.res.Resources; 20import android.text.TextUtils; 21 22import com.android.inputmethod.keyboard.Keyboard; 23import com.android.inputmethod.latin.LatinImeLogger; 24import com.android.inputmethod.latin.R; 25import com.android.inputmethod.latin.Utils; 26 27import java.util.ArrayList; 28import java.util.Arrays; 29 30/** 31 * String parser of moreKeys attribute of Key. 32 * The string is comma separated texts each of which represents one "more key". 33 * - String resource can be embedded into specification @string/name. This is done before parsing 34 * comma. 35 * Each "more key" specification is one of the following: 36 * - A single letter (Letter) 37 * - Label optionally followed by keyOutputText or code (keyLabel|keyOutputText). 38 * - Icon followed by keyOutputText or code (@icon/icon_name|@integer/key_code) 39 * Special character, comma ',' backslash '\', and bar '|' can be escaped by '\' character. 40 * Note that the character '@' and '\' are also parsed by XML parser and CSV parser as well. 41 * See {@link KeyboardIconsSet} about icon_name. 42 */ 43public class KeySpecParser { 44 private static final boolean DEBUG = LatinImeLogger.sDBG; 45 46 private static final int MAX_STRING_REFERENCE_INDIRECTION = 10; 47 48 // Constants for parsing. 49 private static int COMMA = ','; 50 private static final char ESCAPE_CHAR = '\\'; 51 private static final char PREFIX_AT = '@'; 52 private static final char SUFFIX_SLASH = '/'; 53 private static final String PREFIX_STRING = PREFIX_AT + "string" + SUFFIX_SLASH; 54 private static final char LABEL_END = '|'; 55 private static final String PREFIX_ICON = PREFIX_AT + "icon" + SUFFIX_SLASH; 56 private static final String PREFIX_CODE = PREFIX_AT + "integer" + SUFFIX_SLASH; 57 private static final String ADDITIONAL_MORE_KEY_MARKER = "%"; 58 59 private KeySpecParser() { 60 // Intentional empty constructor for utility class. 61 } 62 63 private static boolean hasIcon(String moreKeySpec) { 64 if (moreKeySpec.startsWith(PREFIX_ICON)) { 65 final int end = indexOfLabelEnd(moreKeySpec, 0); 66 if (end > 0) { 67 return true; 68 } 69 throw new KeySpecParserError("outputText or code not specified: " + moreKeySpec); 70 } 71 return false; 72 } 73 74 private static boolean hasCode(String moreKeySpec) { 75 final int end = indexOfLabelEnd(moreKeySpec, 0); 76 if (end > 0 && end + 1 < moreKeySpec.length() 77 && moreKeySpec.substring(end + 1).startsWith(PREFIX_CODE)) { 78 return true; 79 } 80 return false; 81 } 82 83 private static String parseEscape(String text) { 84 if (text.indexOf(ESCAPE_CHAR) < 0) { 85 return text; 86 } 87 final int length = text.length(); 88 final StringBuilder sb = new StringBuilder(); 89 for (int pos = 0; pos < length; pos++) { 90 final char c = text.charAt(pos); 91 if (c == ESCAPE_CHAR && pos + 1 < length) { 92 // Skip escape char 93 pos++; 94 sb.append(text.charAt(pos)); 95 } else { 96 sb.append(c); 97 } 98 } 99 return sb.toString(); 100 } 101 102 private static int indexOfLabelEnd(String moreKeySpec, int start) { 103 if (moreKeySpec.indexOf(ESCAPE_CHAR, start) < 0) { 104 final int end = moreKeySpec.indexOf(LABEL_END, start); 105 if (end == 0) { 106 throw new KeySpecParserError(LABEL_END + " at " + start + ": " + moreKeySpec); 107 } 108 return end; 109 } 110 final int length = moreKeySpec.length(); 111 for (int pos = start; pos < length; pos++) { 112 final char c = moreKeySpec.charAt(pos); 113 if (c == ESCAPE_CHAR && pos + 1 < length) { 114 // Skip escape char 115 pos++; 116 } else if (c == LABEL_END) { 117 return pos; 118 } 119 } 120 return -1; 121 } 122 123 public static String getLabel(String moreKeySpec) { 124 if (hasIcon(moreKeySpec)) { 125 return null; 126 } 127 final int end = indexOfLabelEnd(moreKeySpec, 0); 128 final String label = (end > 0) ? parseEscape(moreKeySpec.substring(0, end)) 129 : parseEscape(moreKeySpec); 130 if (TextUtils.isEmpty(label)) { 131 throw new KeySpecParserError("Empty label: " + moreKeySpec); 132 } 133 return label; 134 } 135 136 private static String getOutputTextInternal(String moreKeySpec) { 137 final int end = indexOfLabelEnd(moreKeySpec, 0); 138 if (end <= 0) { 139 return null; 140 } 141 if (indexOfLabelEnd(moreKeySpec, end + 1) >= 0) { 142 throw new KeySpecParserError("Multiple " + LABEL_END + ": " + moreKeySpec); 143 } 144 return parseEscape(moreKeySpec.substring(end + /* LABEL_END */1)); 145 } 146 147 public static String getOutputText(String moreKeySpec) { 148 if (hasCode(moreKeySpec)) { 149 return null; 150 } 151 final String outputText = getOutputTextInternal(moreKeySpec); 152 if (outputText != null) { 153 if (Utils.codePointCount(outputText) == 1) { 154 // If output text is one code point, it should be treated as a code. 155 // See {@link #getCode(Resources, String)}. 156 return null; 157 } 158 if (!TextUtils.isEmpty(outputText)) { 159 return outputText; 160 } 161 throw new KeySpecParserError("Empty outputText: " + moreKeySpec); 162 } 163 final String label = getLabel(moreKeySpec); 164 if (label == null) { 165 throw new KeySpecParserError("Empty label: " + moreKeySpec); 166 } 167 // Code is automatically generated for one letter label. See {@link getCode()}. 168 return (Utils.codePointCount(label) == 1) ? null : label; 169 } 170 171 public static int getCode(Resources res, String moreKeySpec) { 172 if (hasCode(moreKeySpec)) { 173 final int end = indexOfLabelEnd(moreKeySpec, 0); 174 if (indexOfLabelEnd(moreKeySpec, end + 1) >= 0) { 175 throw new KeySpecParserError("Multiple " + LABEL_END + ": " + moreKeySpec); 176 } 177 final int resId = getResourceId(res, 178 moreKeySpec.substring(end + /* LABEL_END */1 + /* PREFIX_AT */1), 179 R.string.english_ime_name); 180 final int code = res.getInteger(resId); 181 return code; 182 } 183 final String outputText = getOutputTextInternal(moreKeySpec); 184 if (outputText != null) { 185 // If output text is one code point, it should be treated as a code. 186 // See {@link #getOutputText(String)}. 187 if (Utils.codePointCount(outputText) == 1) { 188 return outputText.codePointAt(0); 189 } 190 return Keyboard.CODE_OUTPUT_TEXT; 191 } 192 final String label = getLabel(moreKeySpec); 193 // Code is automatically generated for one letter label. 194 if (Utils.codePointCount(label) == 1) { 195 return label.codePointAt(0); 196 } 197 return Keyboard.CODE_OUTPUT_TEXT; 198 } 199 200 public static int getIconId(String moreKeySpec) { 201 if (hasIcon(moreKeySpec)) { 202 final int end = moreKeySpec.indexOf(LABEL_END, PREFIX_ICON.length()); 203 final String name = moreKeySpec.substring(PREFIX_ICON.length(), end); 204 return KeyboardIconsSet.getIconId(name); 205 } 206 return KeyboardIconsSet.ICON_UNDEFINED; 207 } 208 209 public static String[] insertAddtionalMoreKeys(String[] moreKeys, String[] additionalMoreKeys) { 210 final int moreKeysCount = (moreKeys != null) ? moreKeys.length : 0; 211 final int additionalCount = (additionalMoreKeys != null) ? additionalMoreKeys.length : 0; 212 ArrayList<String> out = null; 213 int additionalIndex = 0; 214 for (int moreKeyIndex = 0; moreKeyIndex < moreKeysCount; moreKeyIndex++) { 215 final String moreKeySpec = moreKeys[moreKeyIndex]; 216 if (moreKeySpec.equals(ADDITIONAL_MORE_KEY_MARKER)) { 217 if (additionalIndex < additionalCount) { 218 // Replace '%' marker with additional more key specification. 219 final String additionalMoreKey = additionalMoreKeys[additionalIndex]; 220 if (out != null) { 221 out.add(additionalMoreKey); 222 } else { 223 moreKeys[moreKeyIndex] = additionalMoreKey; 224 } 225 additionalIndex++; 226 } else { 227 // Filter out excessive '%' marker. 228 if (out == null) { 229 out = new ArrayList<String>(moreKeyIndex); 230 for (int i = 0; i < moreKeyIndex; i++) { 231 out.add(moreKeys[i]); 232 } 233 } 234 } 235 } else { 236 if (out != null) { 237 out.add(moreKeySpec); 238 } 239 } 240 } 241 if (additionalCount > 0 && additionalIndex == 0) { 242 // No '%' marker is found in more keys. 243 // Insert all additional more keys to the head of more keys. 244 if (DEBUG && out != null) { 245 throw new RuntimeException("Internal logic error:" 246 + " moreKeys=" + Arrays.toString(moreKeys) 247 + " additionalMoreKeys=" + Arrays.toString(additionalMoreKeys)); 248 } 249 out = new ArrayList<String>(additionalCount + moreKeysCount); 250 for (int i = additionalIndex; i < additionalCount; i++) { 251 out.add(additionalMoreKeys[i]); 252 } 253 for (int i = 0; i < moreKeysCount; i++) { 254 out.add(moreKeys[i]); 255 } 256 } else if (additionalIndex < additionalCount) { 257 // The number of '%' markers are less than additional more keys. 258 // Append remained additional more keys to the tail of more keys. 259 if (DEBUG && out != null) { 260 throw new RuntimeException("Internal logic error:" 261 + " moreKeys=" + Arrays.toString(moreKeys) 262 + " additionalMoreKeys=" + Arrays.toString(additionalMoreKeys)); 263 } 264 out = new ArrayList<String>(moreKeysCount); 265 for (int i = 0; i < moreKeysCount; i++) { 266 out.add(moreKeys[i]); 267 } 268 for (int i = additionalIndex; i < additionalCount; i++) { 269 out.add(additionalMoreKeys[additionalIndex]); 270 } 271 } 272 if (out != null) { 273 return out.size() > 0 ? out.toArray(new String[out.size()]) : null; 274 } else { 275 return moreKeys; 276 } 277 } 278 279 @SuppressWarnings("serial") 280 public static class KeySpecParserError extends RuntimeException { 281 public KeySpecParserError(String message) { 282 super(message); 283 } 284 } 285 286 private static int getResourceId(Resources res, String name, int packageNameResId) { 287 String packageName = res.getResourcePackageName(packageNameResId); 288 int resId = res.getIdentifier(name, null, packageName); 289 if (resId == 0) { 290 throw new RuntimeException("Unknown resource: " + name); 291 } 292 return resId; 293 } 294 295 private static String resolveStringResource(String rawText, Resources res, 296 int packageNameResId) { 297 int level = 0; 298 String text = rawText; 299 StringBuilder sb; 300 do { 301 level++; 302 if (level >= MAX_STRING_REFERENCE_INDIRECTION) { 303 throw new RuntimeException("too many @string/resource indirection: " + text); 304 } 305 306 final int size = text.length(); 307 if (size < PREFIX_STRING.length()) { 308 return text; 309 } 310 311 sb = null; 312 for (int pos = 0; pos < size; pos++) { 313 final char c = text.charAt(pos); 314 if (c == PREFIX_AT && text.startsWith(PREFIX_STRING, pos)) { 315 if (sb == null) { 316 sb = new StringBuilder(text.substring(0, pos)); 317 } 318 final int end = searchResourceNameEnd(text, pos + PREFIX_STRING.length()); 319 final String resName = text.substring(pos + 1, end); 320 final int resId = getResourceId(res, resName, packageNameResId); 321 sb.append(res.getString(resId)); 322 pos = end - 1; 323 } else if (c == ESCAPE_CHAR) { 324 if (sb != null) { 325 // Append both escape character and escaped character. 326 sb.append(text.substring(pos, Math.min(pos + 2, size))); 327 } 328 pos++; 329 } else if (sb != null) { 330 sb.append(c); 331 } 332 } 333 334 if (sb != null) { 335 text = sb.toString(); 336 } 337 } while (sb != null); 338 339 return text; 340 } 341 342 private static int searchResourceNameEnd(String text, int start) { 343 final int size = text.length(); 344 for (int pos = start; pos < size; pos++) { 345 final char c = text.charAt(pos); 346 // String resource name should be consisted of [a-z_0-9]. 347 if ((c >= 'a' && c <= 'z') || c == '_' || (c >= '0' && c <= '9')) { 348 continue; 349 } 350 return pos; 351 } 352 return size; 353 } 354 355 public static String[] parseCsvString(String rawText, Resources res, int packageNameResId) { 356 final String text = resolveStringResource(rawText, res, packageNameResId); 357 final int size = text.length(); 358 if (size == 0) { 359 return null; 360 } 361 if (Utils.codePointCount(text) == 1) { 362 return text.codePointAt(0) == COMMA ? null : new String[] { text }; 363 } 364 365 ArrayList<String> list = null; 366 int start = 0; 367 for (int pos = 0; pos < size; pos++) { 368 final char c = text.charAt(pos); 369 if (c == COMMA) { 370 // Skip empty entry. 371 if (pos - start > 0) { 372 if (list == null) { 373 list = new ArrayList<String>(); 374 } 375 list.add(text.substring(start, pos)); 376 } 377 // Skip comma 378 start = pos + 1; 379 } else if (c == ESCAPE_CHAR) { 380 // Skip escape character and escaped character. 381 pos++; 382 } 383 } 384 final String remain = (size - start > 0) ? text.substring(start) : null; 385 if (list == null) { 386 return remain != null ? new String[] { remain } : null; 387 } else { 388 if (remain != null) { 389 list.add(remain); 390 } 391 return list.toArray(new String[list.size()]); 392 } 393 } 394} 395