Touch slop added to double tap detection

Similar to what is done in GestureDetector

Removed all gesture constants. Only one one them is used on MOVE
(added an early exit test), the 2 others on UP or DOWN where
performance is not such an issue.

Change-Id: Icd58ead5078f94f86786f934ddf81aa5ec9bf549

1 files changed, 50 insertions, 28 deletions

diff --git a/core/java/android/widget/TextView.java b/core/java/android/widget/TextView.java
index 02144a82842e..c4e4e3e4004e 100644
--- a/core/java/android/widget/TextView.java
+++ b/core/java/android/widget/TextView.java
@@ -357,7 +357,6 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
     private float mLastDownPositionX, mLastDownPositionY;
     private Callback mCustomSelectionActionModeCallback;
 
-    private final int mSquaredTouchSlopDistance;
     // Set when this TextView gained focus with some text selected. Will start selection mode.
     private boolean mCreatedWithASelection = false;
 
@@ -443,15 +442,12 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
         this(context, null);
     }
 
-    public TextView(Context context,
-                    AttributeSet attrs) {
+    public TextView(Context context, AttributeSet attrs) {
         this(context, attrs, com.android.internal.R.attr.textViewStyle);
     }
 
     @SuppressWarnings("deprecation")
-    public TextView(Context context,
-                    AttributeSet attrs,
-                    int defStyle) {
+    public TextView(Context context, AttributeSet attrs, int defStyle) {
         super(context, attrs, defStyle);
         mText = "";
 
@@ -1134,10 +1130,6 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
         setLongClickable(longClickable);
 
         prepareCursorControllers();
-
-        final ViewConfiguration viewConfiguration = ViewConfiguration.get(context);
-        final int touchSlop = viewConfiguration.getScaledTouchSlop();
-        mSquaredTouchSlopDistance = touchSlop * touchSlop;
     }
 
     private void setTypefaceByIndex(int typefaceIndex, int styleIndex) {
@@ -3202,8 +3194,7 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
 
         int n = mFilters.length;
         for (int i = 0; i < n; i++) {
-            CharSequence out = mFilters[i].filter(text, 0, text.length(),
-                                                  EMPTY_SPANNED, 0, 0);
+            CharSequence out = mFilters[i].filter(text, 0, text.length(), EMPTY_SPANNED, 0, 0);
             if (out != null) {
                 text = out;
             }
@@ -5621,11 +5612,13 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
         return super.onKeyUp(keyCode, event);
     }
 
-    @Override public boolean onCheckIsTextEditor() {
+    @Override
+    public boolean onCheckIsTextEditor() {
         return mInputType != EditorInfo.TYPE_NULL;
     }
 
-    @Override public InputConnection onCreateInputConnection(EditorInfo outAttrs) {
+    @Override
+    public InputConnection onCreateInputConnection(EditorInfo outAttrs) {
         if (onCheckIsTextEditor() && isEnabled()) {
             if (mInputMethodState == null) {
                 mInputMethodState = new InputMethodState();
@@ -9248,7 +9241,6 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
         boolean vibrate = true;
 
         if (super.performLongClick()) {
-            mDiscardNextActionUp = true;
             handled = true;
         }
 
@@ -10798,7 +10790,12 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
                         final float deltaX = mDownPositionX - ev.getRawX();
                         final float deltaY = mDownPositionY - ev.getRawY();
                         final float distanceSquared = deltaX * deltaX + deltaY * deltaY;
-                        if (distanceSquared < mSquaredTouchSlopDistance) {
+
+                        final ViewConfiguration viewConfiguration = ViewConfiguration.get(
+                                TextView.this.getContext());
+                        final int touchSlop = viewConfiguration.getScaledTouchSlop();
+
+                        if (distanceSquared < touchSlop * touchSlop) {
                             if (mActionPopupWindow != null && mActionPopupWindow.isShowing()) {
                                 // Tapping on the handle dismisses the displayed action popup
                                 mActionPopupWindow.hide();
@@ -11012,7 +11009,8 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
 
         // Double tap detection
         private long mPreviousTapUpTime = 0;
-        private float mPreviousTapPositionX, mPreviousTapPositionY;
+        private float mDownPositionX, mDownPositionY;
+        private boolean mGestureStayedInTapRegion;
 
         SelectionModifierCursorController() {
             resetTouchOffsets();
@@ -11075,20 +11073,28 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
                     mMinTouchOffset = mMaxTouchOffset = getOffsetForPosition(x, y);
 
                     // Double tap detection
-                    long duration = SystemClock.uptimeMillis() - mPreviousTapUpTime;
-                    if (duration <= ViewConfiguration.getDoubleTapTimeout() &&
-                            isPositionOnText(x, y)) {
-                        final float deltaX = x - mPreviousTapPositionX;
-                        final float deltaY = y - mPreviousTapPositionY;
-                        final float distanceSquared = deltaX * deltaX + deltaY * deltaY;
-                        if (distanceSquared < mSquaredTouchSlopDistance) {
-                            startSelectionActionMode();
-                            mDiscardNextActionUp = true;
+                    if (mGestureStayedInTapRegion) {
+                        long duration = SystemClock.uptimeMillis() - mPreviousTapUpTime;
+                        if (duration <= ViewConfiguration.getDoubleTapTimeout()) {
+                            final float deltaX = x - mDownPositionX;
+                            final float deltaY = y - mDownPositionY;
+                            final float distanceSquared = deltaX * deltaX + deltaY * deltaY;
+
+                            ViewConfiguration viewConfiguration = ViewConfiguration.get(
+                                    TextView.this.getContext());
+                            int doubleTapSlop = viewConfiguration.getScaledDoubleTapSlop();
+                            boolean stayedInArea = distanceSquared < doubleTapSlop * doubleTapSlop;
+
+                            if (stayedInArea && isPositionOnText(x, y)) {
+                                startSelectionActionMode();
+                                mDiscardNextActionUp = true;
+                            }
                         }
                     }
 
-                    mPreviousTapPositionX = x;
-                    mPreviousTapPositionY = y;
+                    mDownPositionX = x;
+                    mDownPositionY = y;
+                    mGestureStayedInTapRegion = true;
                     break;
 
                 case MotionEvent.ACTION_POINTER_DOWN:
@@ -11101,6 +11107,22 @@ public class TextView extends View implements ViewTreeObserver.OnPreDrawListener
                     }
                     break;
 
+                case MotionEvent.ACTION_MOVE:
+                    if (mGestureStayedInTapRegion) {
+                        final float deltaX = event.getX() - mDownPositionX;
+                        final float deltaY = event.getY() - mDownPositionY;
+                        final float distanceSquared = deltaX * deltaX + deltaY * deltaY;
+
+                        final ViewConfiguration viewConfiguration = ViewConfiguration.get(
+                                TextView.this.getContext());
+                        int doubleTapTouchSlop = viewConfiguration.getScaledDoubleTapTouchSlop();
+
+                        if (distanceSquared > doubleTapTouchSlop * doubleTapTouchSlop) {
+                            mGestureStayedInTapRegion = false;
+                        }
+                    }
+                    break;
+
                 case MotionEvent.ACTION_UP:
                     mPreviousTapUpTime = SystemClock.uptimeMillis();
                     break;