Calculate default touch position correction data for keys on 4th row

This change also disables touch position correction for Phone/Dvorak
keyboard.

Bug: 7243101
Change-Id: Idfcc7ad1feabbe6a81635dceba5be087401fa18b

2 files changed, 21 insertions, 17 deletions

diff --git a/java/src/com/android/inputmethod/keyboard/ProximityInfo.java b/java/src/com/android/inputmethod/keyboard/ProximityInfo.java
index 6e138946f..06a9e9252 100644
--- a/java/src/com/android/inputmethod/keyboard/ProximityInfo.java
+++ b/java/src/com/android/inputmethod/keyboard/ProximityInfo.java
@@ -25,15 +25,15 @@ import com.android.inputmethod.latin.JniUtils;
 
 import java.util.Arrays;
 
-public class ProximityInfo {
+public final class ProximityInfo {
     /** MAX_PROXIMITY_CHARS_SIZE must be the same as MAX_PROXIMITY_CHARS_SIZE_INTERNAL
      * in defines.h */
     public static final int MAX_PROXIMITY_CHARS_SIZE = 16;
     /** Number of key widths from current touch point to search for nearest keys. */
     private static float SEARCH_DISTANCE = 1.2f;
     private static final Key[] EMPTY_KEY_ARRAY = new Key[0];
+    private static final float DEFAULT_TOUCH_POSITION_CORRECTION_RADIUS = 0.15f;
 
-    private final int mKeyHeight;
     private final int mGridWidth;
     private final int mGridHeight;
     private final int mGridSize;
@@ -43,6 +43,7 @@ public class ProximityInfo {
     private final int mKeyboardMinWidth;
     private final int mKeyboardHeight;
     private final int mMostCommonKeyWidth;
+    private final int mMostCommonKeyHeight;
     private final Key[] mKeys;
     private final Key[][] mGridNeighbors;
     private final String mLocaleStr;
@@ -63,7 +64,7 @@ public class ProximityInfo {
         mCellHeight = (height + mGridHeight - 1) / mGridHeight;
         mKeyboardMinWidth = minWidth;
         mKeyboardHeight = height;
-        mKeyHeight = mostCommonKeyHeight;
+        mMostCommonKeyHeight = mostCommonKeyHeight;
         mMostCommonKeyWidth = mostCommonKeyWidth;
         mKeys = keys;
         mGridNeighbors = new Key[mGridSize][];
@@ -142,22 +143,22 @@ public class ProximityInfo {
             sweetSpotCenterXs = new float[keyCount];
             sweetSpotCenterYs = new float[keyCount];
             sweetSpotRadii = new float[keyCount];
+            final float defaultRadius = DEFAULT_TOUCH_POSITION_CORRECTION_RADIUS
+                    * (float)Math.hypot(mMostCommonKeyWidth, mMostCommonKeyHeight);
             for (int i = 0; i < keyCount; i++) {
                 final Key key = keys[i];
                 final Rect hitBox = key.mHitBox;
-                final int row = hitBox.top / mKeyHeight;
+                sweetSpotCenterXs[i] = hitBox.exactCenterX();
+                sweetSpotCenterYs[i] = hitBox.exactCenterY();
+                sweetSpotRadii[i] = defaultRadius;
+                final int row = hitBox.top / mMostCommonKeyHeight;
                 if (row < touchPositionCorrection.getRows()) {
                     final int hitBoxWidth = hitBox.width();
                     final int hitBoxHeight = hitBox.height();
-                    final float x = touchPositionCorrection.getX(row);
-                    final float y = touchPositionCorrection.getY(row);
-                    final float radius = touchPositionCorrection.getRadius(row);
-                    sweetSpotCenterXs[i] = hitBox.exactCenterX() + x * hitBoxWidth;
-                    sweetSpotCenterYs[i] = hitBox.exactCenterY() + y * hitBoxHeight;
-                    // Note that, in recent versions of Android, FloatMath is actually slower than
-                    // java.lang.Math due to the way the JIT optimizes java.lang.Math.
-                    sweetSpotRadii[i] = radius * (float)Math.sqrt(
-                            hitBoxWidth * hitBoxWidth + hitBoxHeight * hitBoxHeight);
+                    final float hitBoxDiagonal = (float)Math.hypot(hitBoxWidth, hitBoxHeight);
+                    sweetSpotCenterXs[i] += touchPositionCorrection.getX(row) * hitBoxWidth;
+                    sweetSpotCenterYs[i] += touchPositionCorrection.getY(row) * hitBoxHeight;
+                    sweetSpotRadii[i] = touchPositionCorrection.getRadius(row) * hitBoxDiagonal;
                 }
             }
         } else {
@@ -213,7 +214,8 @@ public class ProximityInfo {
         }
     }
 
-    public void fillArrayWithNearestKeyCodes(int x, int y, int primaryKeyCode, int[] dest) {
+    public void fillArrayWithNearestKeyCodes(final int x, final int y, final int primaryKeyCode,
+            final int[] dest) {
         final int destLength = dest.length;
         if (destLength < 1) {
             return;
@@ -238,7 +240,7 @@ public class ProximityInfo {
         }
     }
 
-    public Key[] getNearestKeys(int x, int y) {
+    public Key[] getNearestKeys(final int x, final int y) {
         if (mGridNeighbors == null) {
             return EMPTY_KEY_ARRAY;
         }
diff --git a/java/src/com/android/inputmethod/keyboard/internal/TouchPositionCorrection.java b/java/src/com/android/inputmethod/keyboard/internal/TouchPositionCorrection.java
index 811a620b3..d8950a713 100644
--- a/java/src/com/android/inputmethod/keyboard/internal/TouchPositionCorrection.java
+++ b/java/src/com/android/inputmethod/keyboard/internal/TouchPositionCorrection.java
@@ -18,7 +18,7 @@ package com.android.inputmethod.keyboard.internal;
 
 import com.android.inputmethod.latin.LatinImeLogger;
 
-public class TouchPositionCorrection {
+public final class TouchPositionCorrection {
     private static final int TOUCH_POSITION_CORRECTION_RECORD_SIZE = 3;
 
     private boolean mEnabled;
@@ -80,7 +80,9 @@ public class TouchPositionCorrection {
     }
 
     public float getX(final int row) {
-        return mXs[row];
+        return 0.0f;
+        // Touch position correction data for X coordinate is obsolete.
+        // return mXs[row];
     }
 
     public float getY(final int row) {