New avatar button: Consolidate text elision between Mac and Win/Linux

ui/gfx/text_elider.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // This file implements utility functions for eliding and formatting UI text.
 //
 // Note that several of the functions declared in text_elider.h are implemented
 // in this file using helper classes in an unnamed namespace.
 
 #include "ui/gfx/text_elider.h"
@@ skipping 737 matching lines @@
   RectangleText rect(font_list,
                      available_pixel_width,
                      available_pixel_height,
                      wrap_behavior,
                      lines);
   rect.Init();
   rect.AddString(input);
   return rect.Finalize();
 }
 
-base::string16 TruncateString(const base::string16& string, size_t length) {
+base::string16 TruncateString(const base::string16& string,
+                              size_t length,
+                              BreakType break_type) {
+  DCHECK(break_type == CHARACTER_BREAK || break_type == WORD_BREAK);
+
   if (string.size() <= length)
     // String fits, return it.
     return string;
 
   if (length == 0)
     // No room for the elide string, return an empty string.
     return base::string16();
 
   size_t max = length - 1;
 
   // Added to the end of strings that are too big.
   static const base::char16 kElideString[] = { 0x2026, 0 };
 
   if (max == 0)
     // Just enough room for the elide string.
     return kElideString;
 
-  // Use a line iterator to find the first boundary.
-  UErrorCode status = U_ZERO_ERROR;
-  scoped_ptr<icu::RuleBasedBreakIterator> bi(
-      static_cast<icu::RuleBasedBreakIterator*>(
-          icu::RuleBasedBreakIterator::createLineInstance(
-              icu::Locale::getDefault(), status)));
-  if (U_FAILURE(status))
-    return string.substr(0, max) + kElideString;
-  bi->setText(string.c_str());
-  int32_t index = bi->preceding(static_cast<int32_t>(max));
-  if (index == icu::BreakIterator::DONE) {
-    index = static_cast<int32_t>(max);
-  } else {
-    // Found a valid break (may be the beginning of the string). Now use
-    // a character iterator to find the previous non-whitespace character.
-    icu::StringCharacterIterator char_iterator(string.c_str());
-    if (index == 0) {
-      // No valid line breaks. Start at the end again. This ensures we break
-      // on a valid character boundary.
+  int32_t index = static_cast<int32_t>(max);
+  if (break_type == WORD_BREAK) {
+    // Use a line iterator to find the first boundary.
+    UErrorCode status = U_ZERO_ERROR;
+    scoped_ptr<icu::BreakIterator> bi(
+        icu::RuleBasedBreakIterator::createLineInstance(
+            icu::Locale::getDefault(), status));
+    if (U_FAILURE(status))
+      return string.substr(0, max) + kElideString;
+    bi->setText(string.c_str());
+    index = bi->preceding(index);
+    if (index == icu::BreakIterator::DONE || index == 0) {
+      // We either found no valid line break at all, or one right at the
+      // beginning of the string. Go back to the end; we'll have to break in the
+      // middle of a word.
       index = static_cast<int32_t>(max);
     }
-    char_iterator.setIndex(index);
-    while (char_iterator.hasPrevious()) {
-      char_iterator.previous();
-      if (!(u_isspace(char_iterator.current()) ||
-            u_charType(char_iterator.current()) == U_CONTROL_CHAR ||
-            u_charType(char_iterator.current()) == U_NON_SPACING_MARK)) {
-        // Not a whitespace character. Advance the iterator so that we
-        // include the current character in the truncated string.
-        char_iterator.next();
-        break;
-      }
-    }
-    if (char_iterator.hasPrevious()) {
-      // Found a valid break point.
-      index = char_iterator.getIndex();
-    } else {
-      // String has leading whitespace, return the elide string.
-      return kElideString;
+  }
+
+  // Use a character iterator to find the previous non-whitespace character.
+  icu::StringCharacterIterator char_iterator(string.c_str());
+  char_iterator.setIndex(index);
+  while (char_iterator.hasPrevious()) {
+    char_iterator.previous();
+    if (!(u_isspace(char_iterator.current()) ||
+          u_charType(char_iterator.current()) == U_CONTROL_CHAR ||
+          u_charType(char_iterator.current()) == U_NON_SPACING_MARK)) {
+      // Not a whitespace character. Advance the iterator so that we
+      // include the current character in the truncated string.
+      char_iterator.next();
+      break;
     }
   }
+  if (char_iterator.hasPrevious()) {
+    // Found a valid break point.
+    index = char_iterator.getIndex();
+  } else {
+    // String has leading whitespace, return the elide string.
+    return kElideString;
+  }
+
   return string.substr(0, index) + kElideString;
 }
 
 }  // namespace gfx