Make abstract KeyDetector class

The KeyDetector abstracts key detection algorithm. The
ProximityKeyDetector is one of its concrete implementations.  Another
one that might be called XAxisKeyDetector will follow to realize the
pop-up mini-keyboard behavior described in bug#2959169.

Bug: 2959169
Change-Id: Idd3fc53282e6b721ec7a4ce500af8aba21ce07a3

java/src/com/android/inputmethod/latin/KeyDetector.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2010 Google Inc.
+ *
+ * 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.latin;
+
+import android.inputmethodservice.Keyboard;
+import android.inputmethodservice.Keyboard.Key;
+
+import java.util.List;
+
+abstract class KeyDetector {
+    protected Keyboard mKeyboard;
+    protected Key[] mKeys;
+
+    protected boolean mProximityCorrectOn;
+    protected int mProximityThresholdSquare;
+
+    public Key[] setKeyboard(Keyboard keyboard) {
+        if (keyboard == null)
+            throw new NullPointerException();
+        mKeyboard = keyboard;
+        List<Key> keys = mKeyboard.getKeys();
+        Key[] array = keys.toArray(new Key[keys.size()]);
+        mKeys = array;
+        return array;
+    }
+
+    public void setProximityCorrectionEnabled(boolean enabled) {
+        mProximityCorrectOn = enabled;
+    }
+
+    public boolean isProximityCorrectionEnabled() {
+        return mProximityCorrectOn;
+    }
+
+    public void setProximityThreshold(int threshold) {
+        mProximityThresholdSquare = threshold * threshold;
+    }
+
+    abstract public int[] newCodeArray();
+
+    abstract public int getKeyIndexAndNearbyCodes(int x, int y, int[] allKeys);
+}

java/src/com/android/inputmethod/latin/LatinKeyboardBaseView.java

@@ -45,7 +45,6 @@ import android.widget.TextView;
 
 import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 
 /**
@@ -202,7 +201,7 @@ public class LatinKeyboardBaseView extends View implements View.OnClickListener,
     private final ArrayList<PointerTracker> mPointerTrackers = new ArrayList<PointerTracker>();
     private final float mDebounceHysteresis;
 
-    private final ProximityKeyDetector mProximityKeyDetector = new ProximityKeyDetector();
+    protected KeyDetector mKeyDetector = new ProximityKeyDetector();
 
     // Swipe gesture detector
     private final GestureDetector mGestureDetector;
@@ -473,8 +472,7 @@ public class LatinKeyboardBaseView extends View implements View.OnClickListener,
     public void setOnKeyboardActionListener(OnKeyboardActionListener listener) {
         mKeyboardActionListener = listener;
         for (PointerTracker tracker : mPointerTrackers) {
-            if (tracker != null)
-                tracker.setOnKeyboardActionListener(listener);
+            tracker.setOnKeyboardActionListener(listener);
         }
     }
 
@@ -501,13 +499,10 @@ public class LatinKeyboardBaseView extends View implements View.OnClickListener,
         mHandler.cancelKeyTimers();
         mHandler.cancelPopupPreview();
         mKeyboard = keyboard;
-        LatinImeLogger.onSetKeyboard(mKeyboard);
-        List<Key> keys = mKeyboard.getKeys();
-        mKeys = keys.toArray(new Key[keys.size()]);
-        mProximityKeyDetector.setKeyboard(keyboard, mKeys);
+        LatinImeLogger.onSetKeyboard(keyboard);
+        mKeys = mKeyDetector.setKeyboard(keyboard);
         for (PointerTracker tracker : mPointerTrackers) {
-            if (tracker != null)
-                tracker.setKeyboard(mKeys, mDebounceHysteresis);
+            tracker.setKeyboard(mKeys, mDebounceHysteresis);
         }
         requestLayout();
         // Hint to reallocate the buffer if the size changed
@@ -599,14 +594,14 @@ public class LatinKeyboardBaseView extends View implements View.OnClickListener,
      * @param enabled whether or not the proximity correction is enabled
      */
     public void setProximityCorrectionEnabled(boolean enabled) {
-        mProximityKeyDetector.setProximityCorrectionEnabled(enabled);
+        mKeyDetector.setProximityCorrectionEnabled(enabled);
     }
 
     /**
      * Returns true if proximity correction is enabled.
      */
     public boolean isProximityCorrectionEnabled() {
-        return mProximityKeyDetector.isProximityCorrectionEnabled();
+        return mKeyDetector.isProximityCorrectionEnabled();
     }
 
     /**
@@ -658,7 +653,7 @@ public class LatinKeyboardBaseView extends View implements View.OnClickListener,
             dimensionSum += Math.min(key.width, key.height) + key.gap;
         }
         if (dimensionSum < 0 || length == 0) return;
-        mProximityKeyDetector.setProximityThreshold((int) (dimensionSum * 1.4f / length));
+        mKeyDetector.setProximityThreshold((int) (dimensionSum * 1.4f / length));
     }
 
     @Override
@@ -1052,7 +1047,7 @@ public class LatinKeyboardBaseView extends View implements View.OnClickListener,
         // Create pointer trackers until we can get 'id+1'-th tracker, if needed.
         for (int i = pointers.size(); i <= id; i++) {
             final PointerTracker tracker =
-                new PointerTracker(mHandler, mProximityKeyDetector, this);
+                new PointerTracker(mHandler, mKeyDetector, this);
             if (keys != null)
                 tracker.setKeyboard(keys, mDebounceHysteresis);
             if (listener != null)

java/src/com/android/inputmethod/latin/PointerTracker.java

@@ -45,7 +45,7 @@ public class PointerTracker {
 
     private final UIProxy mProxy;
     private final UIHandler mHandler;
-    private final ProximityKeyDetector mKeyDetector;
+    private final KeyDetector mKeyDetector;
     private OnKeyboardActionListener mListener;
 
     private Key[] mKeys;
@@ -77,7 +77,7 @@ public class PointerTracker {
     // pressed key
     private int mPreviousKey = NOT_A_KEY;
 
-    public PointerTracker(UIHandler handler, ProximityKeyDetector keyDetector, UIProxy proxy) {
+    public PointerTracker(UIHandler handler, KeyDetector keyDetector, UIProxy proxy) {
         if (proxy == null || handler == null || keyDetector == null)
             throw new NullPointerException();
         mProxy = proxy;

java/src/com/android/inputmethod/latin/ProximityKeyDetector.java

@@ -16,48 +16,24 @@
 
 package com.android.inputmethod.latin;
 
-import android.inputmethodservice.Keyboard;
 import android.inputmethodservice.Keyboard.Key;
 
 import java.util.Arrays;
 
-class ProximityKeyDetector {
+class ProximityKeyDetector extends KeyDetector {
     private static final int MAX_NEARBY_KEYS = 12;
 
-    private Keyboard mKeyboard;
-    private Key[] mKeys;
-
-    private boolean mProximityCorrectOn;
-    private int mProximityThresholdSquare;
-
     // working area
     private int[] mDistances = new int[MAX_NEARBY_KEYS];
 
-    public void setKeyboard(Keyboard keyboard, Key[] keys) {
-        if (keyboard == null || keys == null)
-            throw new NullPointerException();
-        mKeyboard = keyboard;
-        mKeys = keys;
-    }
-
-    public void setProximityCorrectionEnabled(boolean enabled) {
-        mProximityCorrectOn = enabled;
-    }
-
-    public boolean isProximityCorrectionEnabled() {
-        return mProximityCorrectOn;
-    }
-
-    public void setProximityThreshold(int threshold) {
-        mProximityThresholdSquare = threshold * threshold;
-    }
-
+    @Override
     public int[] newCodeArray() {
         int[] codes = new int[MAX_NEARBY_KEYS];
         Arrays.fill(codes, LatinKeyboardBaseView.NOT_A_KEY);
         return codes;
     }
 
+    @Override
     public int getKeyIndexAndNearbyCodes(int x, int y, int[] allKeys) {
         final Key[] keys = mKeys;
         if (keys == null)