1 files changed, 146 insertions, 0 deletions
diff --git a/java/src/com/android/inputmethod/research/Statistics.java b/java/src/com/android/inputmethod/research/Statistics.java
new file mode 100644
index 000000000..4a2cd079c
--- /dev/null
+++ b/java/src/com/android/inputmethod/research/Statistics.java
@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 2012 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.
+ */
+
+package com.android.inputmethod.research;
+
+import com.android.inputmethod.keyboard.Keyboard;
+
+public class Statistics {
+    // Number of characters entered during a typing session
+    int mCharCount;
+    // Number of letter characters entered during a typing session
+    int mLetterCount;
+    // Number of number characters entered
+    int mNumberCount;
+    // Number of space characters entered
+    int mSpaceCount;
+    // Number of delete operations entered (taps on the backspace key)
+    int mDeleteKeyCount;
+    // Number of words entered during a session.
+    int mWordCount;
+    // Whether the text field was empty upon editing
+    boolean mIsEmptyUponStarting;
+    boolean mIsEmptinessStateKnown;
+
+    // Timers to count average time to enter a key, first press a delete key,
+    // between delete keys, and then to return typing after a delete key.
+    final AverageTimeCounter mKeyCounter = new AverageTimeCounter();
+    final AverageTimeCounter mBeforeDeleteKeyCounter = new AverageTimeCounter();
+    final AverageTimeCounter mDuringRepeatedDeleteKeysCounter = new AverageTimeCounter();
+    final AverageTimeCounter mAfterDeleteKeyCounter = new AverageTimeCounter();
+
+    static class AverageTimeCounter {
+        int mCount;
+        int mTotalTime;
+
+        public void reset() {
+            mCount = 0;
+            mTotalTime = 0;
+        }
+
+        public void add(long deltaTime) {
+            mCount++;
+            mTotalTime += deltaTime;
+        }
+
+        public int getAverageTime() {
+            if (mCount == 0) {
+                return 0;
+            }
+            return mTotalTime / mCount;
+        }
+    }
+
+    // To account for the interruptions when the user's attention is directed elsewhere, times
+    // longer than MIN_TYPING_INTERMISSION are not counted when estimating this statistic.
+    public static final int MIN_TYPING_INTERMISSION = 5 * 1000;  // in milliseconds
+    public static final int MIN_DELETION_INTERMISSION = 15 * 1000;  // in milliseconds
+
+    // The last time that a tap was performed
+    private long mLastTapTime;
+    // The type of the last keypress (delete key or not)
+    boolean mIsLastKeyDeleteKey;
+
+    private static final Statistics sInstance = new Statistics();
+
+    public static Statistics getInstance() {
+        return sInstance;
+    }
+
+    private Statistics() {
+        reset();
+    }
+
+    public void reset() {
+        mCharCount = 0;
+        mLetterCount = 0;
+        mNumberCount = 0;
+        mSpaceCount = 0;
+        mDeleteKeyCount = 0;
+        mWordCount = 0;
+        mIsEmptyUponStarting = true;
+        mIsEmptinessStateKnown = false;
+        mKeyCounter.reset();
+        mBeforeDeleteKeyCounter.reset();
+        mDuringRepeatedDeleteKeysCounter.reset();
+        mAfterDeleteKeyCounter.reset();
+
+        mLastTapTime = 0;
+        mIsLastKeyDeleteKey = false;
+    }
+
+    public void recordChar(int codePoint, long time) {
+        final long delta = time - mLastTapTime;
+        if (codePoint == Keyboard.CODE_DELETE) {
+            mDeleteKeyCount++;
+            if (delta < MIN_DELETION_INTERMISSION) {
+                if (mIsLastKeyDeleteKey) {
+                    mDuringRepeatedDeleteKeysCounter.add(delta);
+                } else {
+                    mBeforeDeleteKeyCounter.add(delta);
+                }
+            }
+            mIsLastKeyDeleteKey = true;
+        } else {
+            mCharCount++;
+            if (Character.isDigit(codePoint)) {
+                mNumberCount++;
+            }
+            if (Character.isLetter(codePoint)) {
+                mLetterCount++;
+            }
+            if (Character.isSpaceChar(codePoint)) {
+                mSpaceCount++;
+            }
+            if (mIsLastKeyDeleteKey && delta < MIN_DELETION_INTERMISSION) {
+                mAfterDeleteKeyCounter.add(delta);
+            } else if (!mIsLastKeyDeleteKey && delta < MIN_TYPING_INTERMISSION) {
+                mKeyCounter.add(delta);
+            }
+            mIsLastKeyDeleteKey = false;
+        }
+        mLastTapTime = time;
+    }
+
+    public void recordWordEntered() {
+        mWordCount++;
+    }
+
+    public void setIsEmptyUponStarting(final boolean isEmpty) {
+        mIsEmptyUponStarting = isEmpty;
+        mIsEmptinessStateKnown = true;
+    }
+}