Add a minimum timeout for double-tap in GestureDetector

Prevent noisy falsing. Minimum timeout is currently 40ms and can be
tuned for later. Consider un-hiding the ViewConfiguration query method
later.

Bug 10476944

Change-Id: Ib470735ec929b0b358fca4597e92dc81084e675f

2 files changed, 21 insertions, 2 deletions

diff --git a/core/java/android/view/GestureDetector.java b/core/java/android/view/GestureDetector.java
index 6bbfe0f..2351548 100644
--- a/core/java/android/view/GestureDetector.java
+++ b/core/java/android/view/GestureDetector.java
@@ -17,7 +17,6 @@
 package android.view;
 
 import android.content.Context;
-import android.os.Build;
 import android.os.Handler;
 import android.os.Message;
 
@@ -202,6 +201,7 @@ public class GestureDetector {
     private static final int LONGPRESS_TIMEOUT = ViewConfiguration.getLongPressTimeout();
     private static final int TAP_TIMEOUT = ViewConfiguration.getTapTimeout();
     private static final int DOUBLE_TAP_TIMEOUT = ViewConfiguration.getDoubleTapTimeout();
+    private static final int DOUBLE_TAP_MIN_TIME = ViewConfiguration.getDoubleTapMinTime();
 
     // constants for Message.what used by GestureHandler below
     private static final int SHOW_PRESS = 1;
@@ -673,7 +673,8 @@ public class GestureDetector {
             return false;
         }
 
-        if (secondDown.getEventTime() - firstUp.getEventTime() > DOUBLE_TAP_TIMEOUT) {
+        final long deltaTime = secondDown.getEventTime() - firstUp.getEventTime();
+        if (deltaTime > DOUBLE_TAP_TIMEOUT || deltaTime < DOUBLE_TAP_MIN_TIME) {
             return false;
         }
 
diff --git a/core/java/android/view/ViewConfiguration.java b/core/java/android/view/ViewConfiguration.java
index f8cb9c0..c3f064f 100644
--- a/core/java/android/view/ViewConfiguration.java
+++ b/core/java/android/view/ViewConfiguration.java
@@ -97,6 +97,13 @@ public class ViewConfiguration {
     private static final int DOUBLE_TAP_TIMEOUT = 300;
 
     /**
+     * Defines the minimum duration in milliseconds between the first tap's up event and
+     * the second tap's down event for an interaction to be considered a
+     * double-tap.
+     */
+    private static final int DOUBLE_TAP_MIN_TIME = 40;
+
+    /**
      * Defines the maximum duration in milliseconds between a touch pad
      * touch and release for a given touch to be considered a tap (click) as
      * opposed to a hover movement gesture.
@@ -436,6 +443,17 @@ public class ViewConfiguration {
     }
 
     /**
+     * @return the minimum duration in milliseconds between the first tap's
+     * up event and the second tap's down event for an interaction to be considered a
+     * double-tap.
+     *
+     * @hide
+     */
+    public static int getDoubleTapMinTime() {
+        return DOUBLE_TAP_MIN_TIME;
+    }
+
+    /**
      * @return the maximum duration in milliseconds between a touch pad
      * touch and release for a given touch to be considered a tap (click) as
      * opposed to a hover movement gesture.