Add third_party/google-input-tools: Take 2

third_party/google_input_tools/src/chrome/os/keyboard/parsedlayout.js

+// Copyright 2014 The ChromeOS IME Authors. All Rights Reserved.
+// limitations under the License.
+// See the License for the specific language governing permissions and
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// distributed under the License is distributed on an "AS-IS" BASIS,
+// Unless required by applicable law or agreed to in writing, software
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// You may obtain a copy of the License at
+// you may not use this file except in compliance with the License.
+// Licensed under the Apache License, Version 2.0 (the "License");
+//
+// Copyright 2013 The ChromeOS VK Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS-IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/**
+ * @fileoverview Defines the parsed layout object which will do layout parsing
+ *     and expose the keymappings and the transforms to Model.
+ */
+
+goog.provide('i18n.input.chrome.vk.ParsedLayout');
+
+goog.require('goog.object');
+goog.require('i18n.input.chrome.vk.KeyCode');
+
+
+
+/**
+ * Creates the parsed layout object per the raw layout info.
+ *
+ * @param {!Object} layout The raw layout object defined in the
+ *     xxx_layout.js.
+ * @constructor
+ */
+i18n.input.chrome.vk.ParsedLayout = function(layout) {
+  /**
+   * The layout code (a.k.a. id).
+   *
+   * @type {string}
+   */
+  this.id = layout['id'];
+
+  /**
+   * The view object needed by UI rendering, including the key
+   * mappings. Some extra keys are not appear in following, which are
+   * '', 's', 'l', 'sl', 'cl', 'sc', 'scl'. They define the key mappings
+   * for each keyboard mode:
+   *   '' means normal;
+   *   's' means SHIFT;
+   *   'l' means CAPSLOCK;
+   *   'c' means CTRL+ALT.
+   * Those modes will be filled when parsing the raw layout.
+   * If certain modes are not defined by the raw layout, this.view.<mode>
+   * won't be filled in.
+   * The mode format is: {
+   *   '<keyChar>': ['<disp type(S|P)>', '<disp chars>', '<commit chars>']
+   * }.
+   *
+   * @type {!Object}
+   */
+  this.view = {
+    'id': layout['id'],
+    'title': layout['title'],
+    'isRTL': layout['direction'] == 'rtl',
+    'is102': !!layout['is102Keyboard'],
+    'mappings': goog.object.create([
+      '', null,
+      's', null,
+      'c', null,
+      'l', null,
+      'sc', null,
+      'cl', null,
+      'sl', null,
+      'scl', null
+    ])
+  };
+
+  /**
+   * The parsed layout transforms. There are only 3 elements of this array.
+   * !st is the long exgexp to match, 2nd is the map of:
+   * <match location>: [<regexp>, <replacement>].
+   * 3rd/4th are the regexp for prefix matches.
+   *
+   * @type {Array.<!Object>}
+   */
+  this.transforms = null;
+
+  /**
+   * The parsed layout ambiguous chars.
+   *
+   * @type {Object}
+   * @private
+   */
+  this.ambiRegex_ = null;
+
+  // Parses the key mapping & transforms of the layout.
+  this.parseKeyMappings_(layout);
+  this.parseTransforms_(layout);
+};
+
+
+/**
+ * Parses the key mappings of the given layout.
+ *
+ * @param {!Object} layout The raw layout object. It's format is:
+ *     id: <layout id> in {string}
+ *     title: <layout title> in {string}
+ *     direction: 'rtl' or 'ltr'
+ *     is102Keyboard: True if vk is 102, False/undefined for 101
+ *     mappings: key map in {Object.<string,string>}
+ *       '': keycodes (each char's charCode represents keycode) in normal state
+ *       s: keycodes in SHIFT state
+ *       c: keycodes in ALTGR state
+ *       l: keycodes in CAPSLOCK state
+ *       <the states could be combined, e.g. ',s,sc,sl,scl'>
+ *     transform: in {Object.<string,string>}
+ *       <regexp>: <replacement>
+ *     historyPruneRegex: <regexp string to represent the ambiguities>.
+ * @private
+ */
+i18n.input.chrome.vk.ParsedLayout.prototype.parseKeyMappings_ = function(
+    layout) {
+  var codes = this.view['is102'] ? i18n.input.chrome.vk.KeyCode.CODES102 :
+      i18n.input.chrome.vk.KeyCode.CODES101;
+
+  var mappings = layout['mappings'];
+  for (var m in mappings) {
+    var map = mappings[m];
+    var modes = m.split(/,/);
+    if (modes.join(',') != m) {
+      modes.push(''); // IE splits 'a,b,' into ['a','b']
+    }
+    var parsed = {};
+    // Example for map is like:
+    //   1) {'': '\u00c0123456...', ...}
+    //   2) {'QWERT': 'QWERT', ...}
+    //   3) {'A': 'aa', ...}
+    //   4) {'BCD': '{{bb}}cd', ...}
+    //   5) {'EFG': '{{S||e||ee}}FG', ...}
+    //   6) {'HI': '{{P||12||H}}i', ...}
+    for (var from in map) {
+      // In case #1, from is '', to is '\u00c0123456...'.
+      // In case #3, from is 'A', to is 'aa'.
+      var to = map[from];
+      if (from == '') {
+        from = codes;
+        // If is 102 keyboard, modify 'to' to be compatible with the old vk.
+        if (this.view['is102']) {
+          // Moves the 26th char {\} to be the 38th char (after {'}).
+          var normalizedTo = to.slice(0, 25);
+          normalizedTo += to.slice(26, 37);
+          normalizedTo += to.charAt(25);
+          normalizedTo += to.slice(37);
+          to = normalizedTo;
+        }
+      }
+      // Replaces some chars for backward compatibility to old layout
+      // definitions.
+      from = from.replace('m', '\u00bd');
+      from = from.replace('=', '\u00bb');
+      from = from.replace(';', '\u00ba');
+      if (from.length == 1) {
+        // Case #3: single char map to chars.
+        parsed[from] = ['S', to, to];
+      } else {
+        var j = 0;
+        for (var i = 0, c; c = from.charAt(i); ++i) {
+          var t = to.charAt(j++);
+          if (t == to.charAt(j) && t == '{') {
+            // Case #4/5/6: {{}} to define single char map to chars.
+            var k = to.indexOf('}}', j);
+            if (k < j) break;
+            var s = to.slice(j + 1, k);
+            var parts = s.split('||');
+            if (parts.length == 3) {
+              // Case #5/6: button/commit chars seperation.
+              parsed[c] = parts;
+            } else if (parts.length == 1) {
+              // Case #4.
+              parsed[c] = ['S', s, s];
+            }
+            j = k + 2;
+          } else {
+            // Normal case: single char map to according single char.
+            parsed[c] = ['S', t, t];
+          }
+        }
+      }
+    }
+    for (var i = 0, mode; mode = modes[i], mode != undefined; ++i) {
+      this.view['mappings'][mode] = parsed;
+    }
+  }
+};
+
+
+/**
+ * Prefixalizes the regexp string.
+ *
+ * @param {string} re_str The original regexp string.
+ * @return {string} The prefixalized the regexp string.
+ * @private
+ */
+i18n.input.chrome.vk.ParsedLayout.prototype.prefixalizeRegexString_ = function(
+    re_str) {
+  // Makes sure [...\[\]...] won't impact the later replaces.
+  re_str = re_str.replace(/\\./g, function(m) {
+    if (/^\\\[/.test(m)) {
+      return '\u0001';
+    }
+    if (/^\\\]/.test(m)) {
+      return '\u0002';
+    }
+    return m;
+  });
+  // Prefixalizes.
+  re_str = re_str.replace(/\\.|\[[^\[\]]*\]|\{.*\}|[^\|\\\(\)\[\]\{\}\*\+\?]/g,
+      function(m) {
+        if (/^\{/.test(m)) {
+          return m;
+        }
+        return '(?:' + m + '|$)';
+      });
+  // Restores the \[\].
+  re_str = re_str.replace(/\u0001/g, '\\[');
+  re_str = re_str.replace(/\u0002/g, '\\]');
+  return re_str;
+};
+
+
+/**
+ * Parses the transforms of the given layout.
+ *
+ * @param {!Object} layout The raw layout object. It's format is:
+ *     id: <layout id> in {string}
+ *     title: <layout title> in {string}
+ *     direction: 'rtl' or 'ltr'
+ *     is102Keyboard: True if vk is 102, False/undefined for 101
+ *     mappings: key map in {Object.<string,string>}
+ *       '': keycodes (each char's charCode represents keycode) in normal state
+ *       s: keycodes in SHIFT state
+ *       c: keycodes in ALTGR state
+ *       l: keycodes in CAPSLOCK state
+ *       <the states could be combined, e.g. ',s,sc,sl,scl'>
+ *     transform: in {Object.<string,string>}
+ *       <regexp>: <replacement>
+ *     historyPruneRegex: <regexp string to represent the ambiguities>.
+ * @private
+ */
+i18n.input.chrome.vk.ParsedLayout.prototype.parseTransforms_ = function(
+    layout) {
+  var transforms = layout['transform'];
+  if (transforms) {
+    // regobjs is RegExp objects of the regexp string.
+    // regexsalone will be used to get the long regexp which concats all the
+    // transform regexp as (...$)|(...$)|...
+    // The long regexp is needed because it is ineffecient to match each regexp
+    // one by one. Instead, we match the long regexp only once. But we need to
+    // know where the match happens and which replacement we need to use.
+    // So regobjs will hold the map between the match location and the
+    // regexp/replacement.
+    var regobjs = [], regexesalone = [], partialRegexs = [];
+    // sum_numgrps is the index of current reg group for future matching.
+    // Don't care about the whole string in array index 0.
+    var sum_numgrps = 1;
+    for (var regex in transforms) {
+      var regobj = new RegExp(regex + '$');
+      var repl = transforms[regex];
+      regobjs[sum_numgrps] = [regobj, repl];
+      regexesalone.push('(' + regex + '$)');
+      partialRegexs.push('^(' + this.prefixalizeRegexString_(regex) + ')');
+      // The match should happen to count braces.
+      var grpCountRegexp = new RegExp(regex + '|.*');
+      // The length attribute would count whole string as well.
+      // However, that extra count 1 is compensated by
+      // extra braces added.
+      var numgrps = grpCountRegexp.exec('').length;
+      sum_numgrps += numgrps;
+    }
+    var longregobj = new RegExp(regexesalone.join('|'));
+    // Saves 2 long regexp objects for later prefix matching.
+    // The reason to save a regexp with '\u0001' is to make sure the whole
+    // string won't match as a prefix for the whole pattern. For example,
+    // 'abc' shouldn't match /abc/.
+    // In above case, /abc/ is prefixalized as re = /(a|$)(b|$)(c|$)/.
+    // 'a', 'ab' & 'abc' can all match re.
+    // So make another re2 = /(a|$)(b|$)(c|$)\u0001/, therefore, 'abc' will
+    // fail to match. Finally, we can use this checks to make sure the prefix
+    // match: "s matches re but it doesn't match re2".
+    var prefixregobj = new RegExp(partialRegexs.join('|'));
+    // Uses reverse-ordered regexp for prefix matching. Details are explained
+    // in predictTransform().
+    var prefixregobj2 = new RegExp(partialRegexs.reverse().join('|'));
+    this.transforms = [longregobj, regobjs, prefixregobj, prefixregobj2];
+  }
+
+  var hisPruReg = layout['historyPruneRegex'];
+  if (hisPruReg) {
+    this.ambiRegex_ = new RegExp('^(' + hisPruReg + ')$');
+  }
+};
+
+
+/**
+ * Predicts whether there would be future transforms for the given string.
+ *
+ * @param {string} text The given string.
+ * @return {number} The matched position in the string. Returns -1 for no match.
+ */
+i18n.input.chrome.vk.ParsedLayout.prototype.predictTransform = function(text) {
+  if (!this.transforms || !text) {
+    return -1;
+  }
+  for (var i = 0; i < text.length; i++) {
+    var s = text.slice(i - text.length);
+    // Uses multiple mathches to make sure the prefix match.
+    // Refers to comments in parseTransforms_() method.
+    var matches = s.match(this.transforms[2]);
+    if (matches && matches[0]) {
+      for (var j = 1; j < matches.length && !matches[j]; j++) {}
+      var matchedIndex = j;
+      // Ties to match the reversed regexp and see whether the matched indexes
+      // are pointed to the same rule.
+      matches = s.match(this.transforms[3]);
+      if (matches && matches[0]) { // This should always match!
+        for (var j = 1; j < matches.length && !matches[j]; j++) {}
+        if (matchedIndex != matches.length - j) {
+          // If the matched and reverse-matched index are not the same, it
+          // means the string must be a prefix, because the layout transforms
+          // shouldn't have duplicated transforms.
+          return i;
+        } else {
+          // Gets the matched rule regexp, and revise it to add a never-matched
+          // char X in the end. And tries to match it with s+X.
+          // If matched, it means the s is a full match instead of a prefix
+          // match.
+          var re = this.transforms[1][matchedIndex][0];
+          re = new RegExp(re.toString().match(/\/(.*)\//)[1] + '\u0001');
+          if (!(s + '\u0001').match(re)) {
+            return i;
+          }
+        }
+      }
+    }
+  }
+  return -1;
+};
+
+
+/**
+ * Applies the layout transform and gets the result.
+ *
+ * @param {string} prevstr The previous text.
+ * @param {number} transat The position of previous transform. If it's -1,
+ *     it means no transform happened.
+ * @param {string} ch The new chars currently added to prevstr.
+ * @return {Object} The transform result. It's format is:
+ *     {back: <the number of chars to be deleted in the end of the prevstr>,
+ *     chars: <the chars to add at the tail after the deletion>}.
+ *     If there is no transform applies, return null.
+ */
+i18n.input.chrome.vk.ParsedLayout.prototype.transform = function(
+    prevstr, transat, ch) {
+  if (!this.transforms) return null;
+
+  var str;
+  if (transat > 0) {
+    str = prevstr.slice(0, transat) + '\u001d' +
+          prevstr.slice(transat) + ch;
+  } else {
+    str = prevstr + ch;
+  }
+  var longr = this.transforms[0];
+  var matchArr = longr.exec(str);
+  if (matchArr) {
+    var rs = this.transforms[1];
+
+    for (var i = 1; i < matchArr.length && !matchArr[i]; i++) {}
+    var matchGroup = i;
+
+    var regobj = rs[matchGroup][0];
+    var repl = rs[matchGroup][1];
+    var m = regobj.exec(str);
+
+    // String visible to user does not have LOOK_BEHIND_SEP_ and chars.
+    // So need to discount them in backspace count.
+    var rmstr = str.slice(m.index);
+    var numseps = rmstr.search('\u001d') > -1 ? 1 : 0;
+    var backlen = rmstr.length - numseps - ch.length;
+
+    var newstr = str.replace(regobj, repl);
+    var replstr = newstr.slice(m.index);
+    replstr = replstr.replace('\u001d', '');
+
+    return {back: backlen, chars: replstr};
+  }
+
+  return null;
+};
+
+
+/**
+ * Gets whether the given chars is ambiguious chars.
+ *
+ * @param {string} chars The chars to be judged.
+ * @return {boolean} True if given chars is ambiguious chars, false
+ *     otherwise.
+ */
+i18n.input.chrome.vk.ParsedLayout.prototype.isAmbiChars = function(chars) {
+  return this.ambiRegex_ ? !!this.ambiRegex_.exec(chars) : false;
+};