Implement Tap-to-Share and Tilt-to-Share (DropShare).

o Text says "Tap to Share", but tilting (the phone on top sends) also works.
o Move text to top. Remove arrows.
o First Accelerometer value takes ~700ms :(
o Only call onP2pSendComplete on success. If the send failed, we retry quietly.
  This improves perceived reliability.
o Reduce debounce from 1000ms to 750ms.

TODO
o Never do orientation change while in the animation activity
o Get rid of black transition when entering/leaivng activity
o Figure out why it takes 700ms to get first accelerometer value
o Improve launch time of animation activity (sometimes it takes 3+ seconds)
o Consider going back to a window overlay?
o Make it snappy snappy snappy

Change-Id: Idbc8e4bb744051b7b69d234a51a3ce69e23b699f

9 files changed, 110 insertions, 103 deletions

diff --git a/res/drawable-hdpi/ic_rotate_arrow.png b/res/drawable-hdpi/ic_rotate_arrow.png
deleted file mode 100644
index 0907772..0000000
--- a/res/drawable-hdpi/ic_rotate_arrow.png
+++ /dev/null
diff --git a/res/drawable-hdpi/ic_rotate_arrow_top.png b/res/drawable-hdpi/ic_rotate_arrow_top.png
deleted file mode 100644
index 966d409..0000000
--- a/res/drawable-hdpi/ic_rotate_arrow_top.png
+++ /dev/null
diff --git a/res/drawable-mdpi/ic_rotate_arrow.png b/res/drawable-mdpi/ic_rotate_arrow.png
deleted file mode 100644
index 0907772..0000000
--- a/res/drawable-mdpi/ic_rotate_arrow.png
+++ /dev/null
diff --git a/res/drawable-mdpi/ic_rotate_arrow_top.png b/res/drawable-mdpi/ic_rotate_arrow_top.png
deleted file mode 100644
index 966d409..0000000
--- a/res/drawable-mdpi/ic_rotate_arrow_top.png
+++ /dev/null
diff --git a/res/layout/screenshot.xml b/res/layout/screenshot.xml
index 81a4096..9f27b7f 100644
--- a/res/layout/screenshot.xml
+++ b/res/layout/screenshot.xml
@@ -27,35 +27,13 @@
     <RelativeLayout android:layout_width="match_parent"
         android:layout_height="match_parent"
     >
-        <ImageView android:id="@+id/rotatetop"
-	        android:layout_width="wrap_content"
-	        android:layout_height="wrap_content"
-	        android:adjustViewBounds="true"
-	        android:src="@drawable/ic_rotate_arrow_top"
-	        android:layout_alignParentRight="true"
-	        android:layout_marginTop="60dip"
-	        android:layout_marginRight="15dip"
-	        android:transformPivotX="0.0px"
-	        android:transformPivotY="100.0px"
-	    />
-	    <ImageView android:id="@+id/rotatebottom"
-	        android:layout_width="wrap_content"
-	        android:layout_height="wrap_content"
-	        android:adjustViewBounds="true"
-	        android:src="@drawable/ic_rotate_arrow"
-	        android:layout_alignParentBottom="true"
-	        android:layout_marginBottom="60dip"
-	        android:layout_marginLeft="15dip"
-	        android:transformPivotX="100.0px"
-	        android:transformPivotY="0.0px"
-	    />
 	    <TextView android:id="@+id/calltoaction"
 		    android:layout_width="fill_parent"
 		    android:layout_height="wrap_content"
 		    android:text="@string/touch"
 		    android:textSize="35px"
-		    android:layout_alignParentBottom="true"
-		    android:paddingBottom="30dip"
+		    android:layout_alignParentTop="true"
+		    android:paddingTop="30dip"
 		    android:gravity="center"
 	    />
     </RelativeLayout>
diff --git a/res/values/strings.xml b/res/values/strings.xml
index a1a7510..2f9f065 100755
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -29,5 +29,5 @@
 
     <!-- Content description of the NFC enabled notification icon for accessibility (not shown on the screen). [CHAR LIMIT=NONE] -->
     <string name="accessibility_nfc_enabled">NFC enabled.</string>
-    <string name="touch">Rotate to share</string>
+    <string name="touch">Tap to share</string>
 </resources>
diff --git a/src/com/android/nfc/P2pAnimationActivity.java b/src/com/android/nfc/P2pAnimationActivity.java
index f54fb0b..fe0edba 100644
--- a/src/com/android/nfc/P2pAnimationActivity.java
+++ b/src/com/android/nfc/P2pAnimationActivity.java
@@ -73,8 +73,6 @@ public class P2pAnimationActivity extends Activity implements Handler.Callback,
     View mScreenshotLayout;
     ImageView mScreenshotView;
     ImageView mClonedView;
-    ImageView mBottomArrow;
-    ImageView mTopArrow;
     ImageView mStars;
     TextView mShareText;
 
@@ -139,8 +137,6 @@ public class P2pAnimationActivity extends Activity implements Handler.Callback,
     }
 
     void playEndAnimation() {
-        mTopArrow.setVisibility(View.GONE);
-        mBottomArrow.setVisibility(View.GONE);
         mShareText.setVisibility(View.GONE);
         mArrowStarsAnimator.cancel();
         switch (mAnimationState) {
@@ -220,8 +216,6 @@ public class P2pAnimationActivity extends Activity implements Handler.Callback,
         mLayoutInflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
         mScreenshotLayout = mLayoutInflater.inflate(R.layout.screenshot, null);
 
-        mBottomArrow = (ImageView) mScreenshotLayout.findViewById(R.id.rotatebottom);
-        mTopArrow = (ImageView) mScreenshotLayout.findViewById(R.id.rotatetop);
         mStars = (ImageView) mScreenshotLayout.findViewById(R.id.stars);
 
         mScreenshotView = (ImageView) mScreenshotLayout.findViewById(R.id.screenshot);
@@ -406,8 +400,6 @@ public class P2pAnimationActivity extends Activity implements Handler.Callback,
 
         int rotation = (int) ((double)ARROW_START_ROTATION * (1.0 - offset) +
                     (double) ARROW_FINISH_ROTATION * offset);
-        mBottomArrow.setRotation(rotation);
-        mTopArrow.setRotation(rotation);
 
         float scale = 1.0f + (0.5f * offset);
         mStars.setScaleX(scale);
@@ -462,7 +454,7 @@ public class P2pAnimationActivity extends Activity implements Handler.Callback,
 
     @Override
     public boolean onTouch(View v, MotionEvent event) {
-        if (sCallback != null) {
+        if (sCallback != null && P2pEventManager.TAP_ENABLED) {
             sCallback.onP2pSendConfirmed();
         }
         return true;
diff --git a/src/com/android/nfc/P2pEventManager.java b/src/com/android/nfc/P2pEventManager.java
index 02f7d76..ba1f57c 100644
--- a/src/com/android/nfc/P2pEventManager.java
+++ b/src/com/android/nfc/P2pEventManager.java
@@ -22,11 +22,15 @@ import android.app.PendingIntent;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
+import android.hardware.Sensor;
+import android.hardware.SensorEvent;
+import android.hardware.SensorEventListener;
+import android.hardware.SensorManager;
 import android.media.AudioManager;
 import android.media.SoundPool;
 import android.os.Vibrator;
 import android.provider.Settings;
-import android.view.OrientationEventListener;
+import android.util.Log;
 
 import com.android.nfc3.R;
 
@@ -42,6 +46,9 @@ public class P2pEventManager implements P2pEventListener {
 
     static final long[] VIBRATION_PATTERN = {0, 100, 10000};
 
+    public static final boolean TILT_ENABLED = true;
+    public static final boolean TAP_ENABLED = true;
+
     final Context mContext;
     final P2pEventListener.Callback mCallback;
     final SharedPreferences mPrefs;
@@ -50,56 +57,83 @@ public class P2pEventManager implements P2pEventListener {
     final int mErrorSound;
     final SoundPool mSoundPool; // playback synchronized on this
     final Vibrator mVibrator;
-    final RotationDetector mRotationDetector;
+    final TiltDetector mTiltDetector;
     final NotificationManager mNotificationManager;
 
-    boolean mAnimating;
+    // only used on UI thread
     boolean mPrefsFirstShare;
+    boolean mAnimating;
+
+    /** Detect if the screen is facing up or down */
+    class TiltDetector implements SensorEventListener {
+        /**
+         * Percent tilt required before triggering detection.
+         * 100 indicates the device must be exactly face-down.
+         */
+        static final int THRESHOLD_PERCENT = 75;
+        final SensorManager mSensorManager;
+        final Sensor mSensor;
 
-    class RotationDetector extends OrientationEventListener {
-        static final int THRESHOLD_DEGREES = 35;
-        int mStartOrientation;
-        boolean mRotateDetectionEnabled;
+        // Only used on UI thread
+        boolean mSensorEnabled;
+        boolean mTriggerEnabled;
+        float mLastValue;
 
-        public RotationDetector(Context context) {
-            super(context);
+        public TiltDetector(Context context) {
+            mSensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);
+            mSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_GRAVITY);
+            mSensorEnabled = false;
+            mTriggerEnabled = false;
+            mLastValue = Float.MIN_VALUE;
         }
-        public void start() {
-            synchronized (RotationDetector.this) {
-                mRotateDetectionEnabled = true;
-                mStartOrientation = -1;
-                super.enable();
+        public void enable() {
+            if (mSensorEnabled) {
+                return;
             }
+            mSensorEnabled = true;
+            mLastValue = Float.MIN_VALUE;
+            mSensorManager.registerListener(this, mSensor, SensorManager.SENSOR_DELAY_UI);
         }
-        public void cancel() {
-            synchronized (RotationDetector.this) {
-                mRotateDetectionEnabled = false;
-                super.disable();
+        public boolean enableTrigger() {
+            if (!mSensorEnabled || mTriggerEnabled) {
+                return false;
             }
+            mTriggerEnabled = true;
+            return checkTrigger();
         }
-        @Override
-        public void onOrientationChanged(int orientation) {
-            synchronized (RotationDetector.this) {
-                if (!mRotateDetectionEnabled) {
-                    return;
-                }
-                if (mStartOrientation < 0) {
-                    mStartOrientation = orientation;
-                }
-                int diff = Math.abs(mStartOrientation - orientation);
-                if (diff > THRESHOLD_DEGREES && diff < (360-THRESHOLD_DEGREES)) {
-                    cancel();
-                    mVibrator.vibrate(VIBRATION_PATTERN, -1);
-                    mCallback.onP2pSendConfirmed();
-                }
+        public void disable() {
+            if (!mSensorEnabled) {
+                return;
             }
+            mSensorManager.unregisterListener(this, mSensor);
+            mSensorEnabled = false;
+            mTriggerEnabled = false;
         }
-    }
+        boolean checkTrigger() {
+            if (!mTriggerEnabled ||
+                    100.0 * mLastValue / SensorManager.GRAVITY_EARTH < THRESHOLD_PERCENT) {
+                return false;
+            }
+            disable();
+            mVibrator.vibrate(VIBRATION_PATTERN, -1);
+            mCallback.onP2pSendConfirmed();
+            return true;
+        }
+        @Override
+        public void onSensorChanged(SensorEvent event) {
+            // always called on UI thread
+            mLastValue = event.values[2];
+            if (DBG) Log.d(TAG, "z=" + mLastValue);
+            checkTrigger();
+        }
+        @Override
+        public void onAccuracyChanged(Sensor arg0, int arg1) { }
+    };
 
     public P2pEventManager(Context context, P2pEventListener.Callback callback) {
         mContext = context;
         mCallback = callback;
-        mRotationDetector = new RotationDetector(mContext);
+        mTiltDetector = new TiltDetector(mContext);
         mSoundPool = new SoundPool(1, AudioManager.STREAM_NOTIFICATION, 0);
         mStartSound = mSoundPool.load(mContext, R.raw.start, 1);
         mEndSound = mSoundPool.load(mContext, R.raw.end, 1);
@@ -119,52 +153,58 @@ public class P2pEventManager implements P2pEventListener {
             mPrefsFirstShare = false;
         }
 
+        P2pAnimationActivity.setCallback(mCallback);
         mAnimating = false;
     }
 
     @Override
     public void onP2pInRange() {
+        if (TILT_ENABLED) {
+            mTiltDetector.enable();
+        }
         mVibrator.vibrate(VIBRATION_PATTERN, -1);
-        playSound(mStartSound);
+        P2pAnimationActivity.makeScreenshot(mContext);
     }
 
     @Override
     public void onP2pSendConfirmationRequested() {
-        mRotationDetector.start();
-        P2pAnimationActivity.makeScreenshot(mContext);
-        P2pAnimationActivity.setCallback(mCallback);
+        if (TILT_ENABLED && mTiltDetector.enableTrigger()) {
+            return;
+        }
+
         mAnimating = true;
         // Start the animation activity
         Intent animIntent = new Intent();
         animIntent.setClass(mContext, P2pAnimationActivity.class);
         animIntent.setFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION | Intent.FLAG_ACTIVITY_NEW_TASK);
         mContext.startActivity(animIntent);
+        playSound(mStartSound);
     }
 
     @Override
-    public void onP2pSendComplete(boolean result) {
-        if (!result) {
-            playSound(mErrorSound);
-        } else {
-            playSound(mEndSound);
-            checkFirstShare();
-        }
-        finish(result, false);
+    public void onP2pSendComplete() {
+        playSound(mEndSound);
+        checkFirstShare();
+        finish(true, false);
     }
 
     @Override
     public void onP2pReceiveComplete() {
-        mRotationDetector.cancel();
+        if (TILT_ENABLED) {
+            mTiltDetector.disable();
+        }
         finish(false, true);
     }
 
     @Override
     public void onP2pOutOfRange() {
-        mRotationDetector.cancel();
+        if (TILT_ENABLED) {
+            mTiltDetector.disable();
+        }
         if (mAnimating) {
-            finish(false, false);
             playSound(mErrorSound);
         }
+        finish(false, false);
     }
 
     /**
@@ -172,18 +212,15 @@ public class P2pEventManager implements P2pEventListener {
      * Must be called on the UI thread.
      */
     void finish(boolean sendSuccess, boolean receiveSuccess) {
+        if (!mAnimating) {
+            return;
+        }
         if (sendSuccess) {
-            if (mAnimating) {
-                P2pAnimationActivity.finishWithSend();
-            }
+            P2pAnimationActivity.finishWithSend();
         } else if (receiveSuccess) {
-            if (mAnimating) {
-                P2pAnimationActivity.finishWithReceive();
-            }
+            P2pAnimationActivity.finishWithReceive();
         } else {
-            if (mAnimating) {
-                P2pAnimationActivity.finishWithFailure();
-            }
+            P2pAnimationActivity.finishWithFailure();
         }
         mAnimating = false;
     }
diff --git a/src/com/android/nfc/P2pLinkManager.java b/src/com/android/nfc/P2pLinkManager.java
index 2fbde95..c3f9fc6 100755
--- a/src/com/android/nfc/P2pLinkManager.java
+++ b/src/com/android/nfc/P2pLinkManager.java
@@ -65,9 +65,9 @@ interface P2pEventListener {
     public void onP2pSendConfirmationRequested();
 
     /**
-     * Called when the send is complete, with the result.
+     * Called to indicate a send was successful.
      */
-    public void onP2pSendComplete(boolean result);
+    public void onP2pSendComplete();
 
     /**
      * Called to indicate a receive was successful.
@@ -96,7 +96,7 @@ public class P2pLinkManager implements Handler.Callback, P2pEventListener.Callba
     // TODO dynamically assign SAP values
     static final int NDEFPUSH_SAP = 0x10;
 
-    static final int LINK_DEBOUNCE_MS = 1000;
+    static final int LINK_DEBOUNCE_MS = 750;
 
     static final int STATE_WAITING = 0;
     static final int STATE_SUCCESS = 1;
@@ -289,9 +289,9 @@ public class P2pLinkManager implements Handler.Callback, P2pEventListener.Callba
          }
      }
 
-    void onSendComplete(boolean result) {
+    void onSendComplete() {
         // Make callbacks on UI thread
-        mHandler.obtainMessage(MSG_SEND_COMPLETE, new Boolean(result)).sendToTarget();
+        mHandler.sendEmptyMessage(MSG_SEND_COMPLETE);
     }
 
     void sendNdefMessage() {
@@ -318,7 +318,6 @@ public class P2pLinkManager implements Handler.Callback, P2pEventListener.Callba
 
             synchronized (P2pLinkManager.this) {
                 if (mLinkState != LINK_STATE_UP || mSendState != SEND_STATE_SENDING) {
-                    onSendComplete(false);
                     return null;
                 }
                 m = mMessageToSend;
@@ -331,13 +330,15 @@ public class P2pLinkManager implements Handler.Callback, P2pEventListener.Callba
                 Log.i(TAG, "Failed to connect over SNEP, trying NPP");
 
                 if (isCancelled()) {
-                    onSendComplete(false);
                     return null;
                 }
 
                 result = new NdefPushClient().push(m);
             }
-            onSendComplete(result);
+            if (DBG) Log.d(TAG, "SendTask result=" + result);
+            if (result) {
+                onSendComplete();
+            }
             return null;
         }
     }
@@ -421,7 +422,6 @@ public class P2pLinkManager implements Handler.Callback, P2pEventListener.Callba
                 }
                 break;
             case MSG_SEND_COMPLETE:
-                boolean result = (Boolean) msg.obj;
                 synchronized (P2pLinkManager.this) {
                     mSendTask = null;
 
@@ -430,7 +430,7 @@ public class P2pLinkManager implements Handler.Callback, P2pEventListener.Callba
                     }
                     mSendState = SEND_STATE_NOTHING_TO_SEND;
                     if (DBG) Log.d(TAG, "onP2pSendComplete()");
-                    mEventListener.onP2pSendComplete(result);
+                    mEventListener.onP2pSendComplete();
                     if (mCallbackNdef != null) {
                         try {
                             mCallbackNdef.onMessagePushed();