Merge lp:~michael-sheldon/ubuntu-keyboard/fix-1347796 into lp:ubuntu-keyboard

[Michael Sheldon]

Calculate the similarity between the current user's input and the prediction candidate, if they differ too much make the user input the primary candidate for auto-completion.

Calculate the similarity between the current user's input and the prediction candidate, if they differ too much make the user input the primary candidate for auto-completion.

[Michael Sheldon (michael-sheldon)]

Are there any related MPs required for this MP to build/function as expected? Please list.

 * No

Is your branch in sync with latest trunk (e.g. bzr pull lp:trunk -> no changes)

 * Yes

Did you perform an exploratory manual test run of your code change and any related functionality on device or emulator?

 * Yes

Did you successfully run all tests found in your component's Test Plan (https://wiki.ubuntu.com/Process/Merges/TestPlan/ubuntu-keyboard) on device or emulator?

 * Yes

If you changed the UI, was the change specified/approved by design?

 * No change

If you changed UI labels, did you update the pot file?

 * No change

If you changed the packaging (debian), did you add a core-dev as a reviewer to this MP?

 * No change

[PS Jenkins bot (ps-jenkins)]

PASSED: Continuous integration, rev:235
http://jenkins.qa.ubuntu.com/job/ubuntu-keyboard-ci/488/
Executed test runs:
    SUCCESS: http://jenkins.qa.ubuntu.com/job/ubuntu-keyboard-utopic-amd64-ci/114
    SUCCESS: http://jenkins.qa.ubuntu.com/job/ubuntu-keyboard-utopic-armhf-ci/113
        deb: http://jenkins.qa.ubuntu.com/job/ubuntu-keyboard-utopic-armhf-ci/113/artifact/work/output/*zip*/output.zip
    SUCCESS: http://jenkins.qa.ubuntu.com/job/ubuntu-keyboard-utopic-i386-ci/113

Click here to trigger a rebuild:
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review: Approve (continuous-integration)

[lp:~michael-sheldon/ubuntu-keyboard/fix-1347796]

236. By Michael Sheldon on 2014-11-12

Merge from trunk

[PS Jenkins bot (ps-jenkins)]

PASSED: Continuous integration, rev:236
http://jenkins.qa.ubuntu.com/job/ubuntu-keyboard-ci/505/
Executed test runs:
    SUCCESS: http://jenkins.qa.ubuntu.com/job/ubuntu-keyboard-vivid-amd64-ci/6
    SUCCESS: http://jenkins.qa.ubuntu.com/job/ubuntu-keyboard-vivid-armhf-ci/6
        deb: http://jenkins.qa.ubuntu.com/job/ubuntu-keyboard-vivid-armhf-ci/6/artifact/work/output/*zip*/output.zip
    SUCCESS: http://jenkins.qa.ubuntu.com/job/ubuntu-keyboard-vivid-i386-ci/6

Click here to trigger a rebuild:
http://s-jenkins.ubuntu-ci:8080/job/ubuntu-keyboard-ci/505/rebuild

review: Approve (continuous-integration)

[Bill Filler (bfiller)]

aprpoved

review: Approve

=== modified file 'plugins/pinyin/src/chineselanguagefeatures.cpp'
--- plugins/pinyin/src/chineselanguagefeatures.cpp	2014-10-22 15:56:37 +0000
+++ plugins/pinyin/src/chineselanguagefeatures.cpp	2014-11-12 14:55:15 +0000
@@ -83,3 +83,8 @@
 
     return false;
 }
+
+bool ChineseLanguageFeatures::ignoreSimilarity() const
+{
+    return true;
+}
 
=== modified file 'plugins/pinyin/src/chineselanguagefeatures.h'
--- plugins/pinyin/src/chineselanguagefeatures.h	2014-09-08 15:09:32 +0000
+++ plugins/pinyin/src/chineselanguagefeatures.h	2014-11-12 14:55:15 +0000
@@ -33,6 +33,7 @@
     virtual QString appendixForReplacedPreedit(const QString &preedit) const;
     virtual bool isSeparator(const QString &text) const;
     virtual bool isSymbol(const QString &text) const;
+    virtual bool ignoreSimilarity() const;
 };
 
 #endif // CHINESELANGUAGEFEATURES_H
 
=== modified file 'plugins/westernsupport/westernlanguagefeatures.cpp'
--- plugins/westernsupport/westernlanguagefeatures.cpp	2014-09-08 15:09:32 +0000
+++ plugins/westernsupport/westernlanguagefeatures.cpp	2014-11-12 14:55:15 +0000
@@ -104,3 +104,8 @@
 
     return false;
 }
+
+bool WesternLanguageFeatures::ignoreSimilarity() const
+{
+    return false;
+}
 
=== modified file 'plugins/westernsupport/westernlanguagefeatures.h'
--- plugins/westernsupport/westernlanguagefeatures.h	2014-09-08 15:09:32 +0000
+++ plugins/westernsupport/westernlanguagefeatures.h	2014-11-12 14:55:15 +0000
@@ -49,6 +49,7 @@
     virtual bool isSeparator(const QString &text) const;
     virtual QString fullStopSequence() const { return QString("."); }
     virtual bool isSymbol(const QString &text) const;
+    virtual bool ignoreSimilarity() const;
 };
 
 #endif // MALIITKEYBOARD_LANGUAGEFEATURES_H
 
=== modified file 'src/lib/logic/abstractlanguagefeatures.h'
--- src/lib/logic/abstractlanguagefeatures.h	2014-09-08 15:09:32 +0000
+++ src/lib/logic/abstractlanguagefeatures.h	2014-11-12 14:55:15 +0000
@@ -48,6 +48,10 @@
     virtual bool isSeparator(const QString &text) const { Q_UNUSED(text); return false; }
     virtual QString fullStopSequence() const { return QString(); }
     virtual bool isSymbol(const QString &text) const { Q_UNUSED(text); return false; }
+    // Typically we disable auto-correct if the predicted word isn't similar
+    // to the user's input. However for input methods such as pinyin this
+    // can be disabled by implementing this method to return true.
+    virtual bool ignoreSimilarity() const { return false; }
 };
 
 #endif // MALIIT_KEYBOARD_ABSTRACTLANGUAGEFEATURES_H
 
=== modified file 'src/lib/logic/wordengine.cpp'
--- src/lib/logic/wordengine.cpp	2014-11-07 11:31:10 +0000
+++ src/lib/logic/wordengine.cpp	2014-11-12 14:55:15 +0000
@@ -345,6 +345,14 @@
         primary.setPrimary(true);
         d->candidates->replace(0, primary);
         Q_EMIT primaryCandidateChanged(primary.word());
+    } else if (!d->languagePlugin->languageFeature()->ignoreSimilarity()
+               && !similarWords(d->candidates->at(0).word(), d->candidates->at(1).word())) {
+        // The prediction is too different to the user input, so the user input 
+        // becomes the primary candidate
+        WordCandidate primary = d->candidates->value(0);
+        primary.setPrimary(true);
+        d->candidates->replace(0, primary);
+        Q_EMIT primaryCandidateChanged(primary.word());
     } else {
         // The first prediction is the primary candidate
         WordCandidate primary = d->candidates->value(1);
@@ -420,6 +428,46 @@
     return d->languagePlugin->languageFeature();
 }
 
+bool WordEngine::similarWords(QString word1, QString word2) {
+    // Calculate the Levenshtein distance between the first word and the 
+    // beginning of the second word. If the distance is too great then word2
+    // is not considered to be a suitable prediction for word1.
+    word2 = word2.left(word1.size());
+    if (word1 == word2) {
+        return true;
+    }
+
+    int *v0 = (int *) malloc(sizeof(int) * word1.size() + 1);
+    int *v1 = (int *) malloc(sizeof(int) * word1.size() + 1);
+
+    for (int i = 0; i < word2.size() + 1; i++) {
+        v0[i] = i;
+        v1[i] = 0;
+    }
+
+    for (int i = 0; i < word1.size(); i++) {
+        v1[0] = i + 1;
+
+        for (int j = 0; j < word2.size(); j++) {
+            int cost = (word1[i] == word2[i]) ? 0 : 1;
+            v1[j + 1] = std::min(v1[j] + 1, v0[j + 1] + 1);
+            v1[j + 1] = std::min(v1[j] + 1, v0[j] + cost);
+        }
+
+        for (int j = 0; j < word1.size() + 1; j++) {
+            v0[j] = v1[j];
+        }
+    }
+
+    double threshold = std::max(word1.size() / 3.0, 3.0);
+    int distance = v1[word2.size()];
+
+    free(v0);
+    free(v1);
+
+    return distance <= threshold;
+}
+
 void WordEngine::clearCandidates()
 {
     Q_D(WordEngine);
 
=== modified file 'src/lib/logic/wordengine.h'
--- src/lib/logic/wordengine.h	2014-10-29 13:57:51 +0000
+++ src/lib/logic/wordengine.h	2014-11-12 14:55:15 +0000
@@ -82,6 +82,7 @@
     virtual void fetchCandidates(Model::Text *text);
     //! \reimp_end
     void calculatePrimaryCandidate();
+    bool similarWords(QString word1, QString word2);
 
     const QScopedPointer<WordEnginePrivate> d_ptr;