added bigram prediction

  - after first character, only suggests bigram data (but doesn't autocomplete)
  - after second character, words from dictionary gets rearranged by using bigram
  - compatible with old dictionary
  - added preference option to disable bigram

Change-Id: Ia8f4e8fa55e797e86d858fd499887cd396388411

4 files changed, 103 insertions, 7 deletions

diff --git a/tests/data/bigramlist.xml b/tests/data/bigramlist.xml
new file mode 100644
index 000000000..dd3f2916e
--- /dev/null
+++ b/tests/data/bigramlist.xml
@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+/*
+**
+** Copyright 2010, The Android Open Source Project
+**
+** 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.
+*/
+-->
+
+<bigrams>
+    <bi w1="I'm" count="1">
+        <w w2="about" p="100" />
+    </bi>
+    <bi w1="about" count="3">
+        <w w2="part" p="117" />
+        <w w2="business" p="100" />
+        <w w2="being" p="10" />
+    </bi>
+    <bi w1="business" count="1">
+        <w w2="people" p="100" />
+    </bi>
+    <bi w1="from" count="1">
+        <w w2="same" p="117" />
+    </bi>
+</bigrams>
diff --git a/tests/data/wordlist.xml b/tests/data/wordlist.xml
index 22d0caa38..b870eb2a3 100644
--- a/tests/data/wordlist.xml
+++ b/tests/data/wordlist.xml
@@ -225,6 +225,7 @@
  <w f="179">services</w>
  <w f="170">niño</w>
  <w f="170">María</w>
+ <w f="70">car</w>
  <w f="0">hmmm</w>
  <w f="0">hon</w>
  <w f="0">tty</w>
diff --git a/tests/res/raw/test.dict b/tests/res/raw/test.dict
index e789aaa9a..6a5d6d794 100644
--- a/tests/res/raw/test.dict
+++ b/tests/res/raw/test.dict
diff --git a/tests/src/com/android/inputmethod/latin/tests/SuggestTests.java b/tests/src/com/android/inputmethod/latin/tests/SuggestTests.java
index 9401d926a..59720640a 100644
--- a/tests/src/com/android/inputmethod/latin/tests/SuggestTests.java
+++ b/tests/src/com/android/inputmethod/latin/tests/SuggestTests.java
@@ -71,7 +71,7 @@ public class SuggestTests extends AndroidTestCase {
             Log.w(TAG, "No available size for binary dictionary");
         }
         mSuggest.setAutoTextEnabled(false);
-        mSuggest.setCorrectionMode(Suggest.CORRECTION_FULL);
+        mSuggest.setCorrectionMode(Suggest.CORRECTION_FULL_BIGRAM);
     }
 
     /************************** Helper functions ************************/
@@ -108,19 +108,56 @@ public class SuggestTests extends AndroidTestCase {
 
     private boolean isDefaultSuggestion(CharSequence typed, CharSequence expected) {
         WordComposer word = createWordComposer(typed);
-        List<CharSequence> suggestions = mSuggest.getSuggestions(null, word, false);
+        List<CharSequence> suggestions = mSuggest.getSuggestions(null, word, false, null);
+        return isDefaultSuggestion(suggestions, expected);
+    }
+
+    private void getBigramSuggestions(CharSequence previous, CharSequence typed) {
+        if(!TextUtils.isEmpty(previous) && (typed.length() > 1)) {
+            WordComposer firstChar = createWordComposer(typed.charAt(0) + "");
+            mSuggest.getSuggestions(null, firstChar, false, previous);
+        }
+    }
+
+    private boolean isDefaultNextSuggestion(CharSequence previous, CharSequence typed,
+            CharSequence expected) {
+        WordComposer word = createWordComposer(typed);
+        getBigramSuggestions(previous, typed);
+        List<CharSequence> suggestions = mSuggest.getSuggestions(null, word, false, previous);
         return isDefaultSuggestion(suggestions, expected);
     }
 
     private boolean isDefaultCorrection(CharSequence typed, CharSequence expected) {
         WordComposer word = createWordComposer(typed);
-        List<CharSequence> suggestions = mSuggest.getSuggestions(null, word, false);
+        List<CharSequence> suggestions = mSuggest.getSuggestions(null, word, false, null);
+        return isDefaultSuggestion(suggestions, expected) && mSuggest.hasMinimalCorrection();
+    }
+
+    private boolean isDefaultNextCorrection(CharSequence previous, CharSequence typed,
+            CharSequence expected) {
+        WordComposer word = createWordComposer(typed);
+        getBigramSuggestions(previous, typed);
+        List<CharSequence> suggestions = mSuggest.getSuggestions(null, word, false, previous);
+        for(int i=0;i<suggestions.size();i++) {
+            Log.i(TAG,i+" "+suggestions.get(i));
+        }
         return isDefaultSuggestion(suggestions, expected) && mSuggest.hasMinimalCorrection();
     }
 
     private boolean isASuggestion(CharSequence typed, CharSequence expected) {
         WordComposer word = createWordComposer(typed);
-        List<CharSequence> suggestions = mSuggest.getSuggestions(null, word, false);
+        List<CharSequence> suggestions = mSuggest.getSuggestions(null, word, false, null);
+        for (int i = 1; i < suggestions.size(); i++) {
+            if (TextUtils.equals(suggestions.get(i), expected)) return true;
+        }
+        return false;
+    }
+
+    private boolean isASuggestion(CharSequence previous, CharSequence typed,
+            CharSequence expected) {
+        WordComposer word = createWordComposer(typed);
+        getBigramSuggestions(previous, typed);
+        List<CharSequence> suggestions = mSuggest.getSuggestions(null, word, false, previous);
         for (int i = 1; i < suggestions.size(); i++) {
             if (TextUtils.equals(suggestions.get(i), expected)) return true;
         }
@@ -241,8 +278,30 @@ public class SuggestTests extends AndroidTestCase {
      * Are accented forms of words suggested as corrections?
      */
     public void testAccents() {
-        assertTrue(isDefaultCorrection("nino", "ni\u00F1o")); // ni–o
-        assertTrue(isDefaultCorrection("nimo", "ni\u00F1o")); // ni–o
-        assertTrue(isDefaultCorrection("maria", "Mar\u00EDa")); // Mar’a
+        assertTrue(isDefaultCorrection("nino", "ni\u00F1o")); // niño
+        assertTrue(isDefaultCorrection("nimo", "ni\u00F1o")); // niño
+        assertTrue(isDefaultCorrection("maria", "Mar\u00EDa")); // María
+    }
+
+    /**
+     * Make sure bigrams are showing when first character is typed
+     *  and don't show any when there aren't any
+     */
+    public void testBigramsAtFirstChar() {
+        assertTrue(isDefaultNextCorrection("about", "p", "part"));
+        assertTrue(isDefaultNextCorrection("I'm", "a", "about"));
+        assertTrue(isDefaultNextCorrection("about", "b", "business"));
+        assertTrue(isASuggestion("about", "b", "being"));
+        assertFalse(isDefaultNextSuggestion("about", "p", "business"));
+    }
+
+    /**
+     * Make sure bigrams score affects the original score
+     */
+    public void testBigramsScoreEffect() {
+       assertTrue(isDefaultCorrection("pa", "page"));
+       assertTrue(isDefaultNextCorrection("about", "pa", "part"));
+       assertTrue(isDefaultCorrection("sa", "said"));
+       assertTrue(isDefaultNextCorrection("from", "sa", "same"));
     }
 }