am 29c041a3: am 88d18b9f: am 4054bd6d: Use gesture detector from support lib

* commit '29c041a3e41b93c7ffd8f29550df501f0b45ea02':
  Use gesture detector from support lib

2 files changed, 8 insertions, 670 deletions

diff --git a/photoviewer/src/com/android/ex/photo/views/GestureDetector.java b/photoviewer/src/com/android/ex/photo/views/GestureDetector.java
deleted file mode 100644
index c117661..0000000
--- a/photoviewer/src/com/android/ex/photo/views/GestureDetector.java
+++ /dev/null
@@ -1,656 +0,0 @@
-/*
- * Copyright (C) 2008 The Android Open Source Project
- *
- * 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.ex.photo.views;
-
-import android.content.Context;
-import android.os.Handler;
-import android.os.Message;
-import android.view.MotionEvent;
-import android.view.VelocityTracker;
-import android.view.View;
-import android.view.ViewConfiguration;
-
-/**
- * Detects various gestures and events using the supplied {@link MotionEvent}s.
- * The {@link OnGestureListener} callback will notify users when a particular
- * motion event has occurred. This class should only be used with {@link MotionEvent}s
- * reported via touch (don't use for trackball events).
- *
- * To use this class:
- * <ul>
- *  <li>Create an instance of the {@code GestureDetector} for your {@link View}
- *  <li>In the {@link View#onTouchEvent(MotionEvent)} method ensure you call
- *          {@link #onTouchEvent(MotionEvent)}. The methods defined in your callback
- *          will be executed when the events occur.
- * </ul>
- */
-public class GestureDetector {
-    /**
-     * The listener that is used to notify when gestures occur.
-     * If you want to listen for all the different gestures then implement
-     * this interface. If you only want to listen for a subset it might
-     * be easier to extend {@link SimpleOnGestureListener}.
-     */
-    public interface OnGestureListener {
-
-        /**
-         * Notified when a tap occurs with the down {@link MotionEvent}
-         * that triggered it. This will be triggered immediately for
-         * every down event. All other events should be preceded by this.
-         *
-         * @param e The down motion event.
-         */
-        boolean onDown(MotionEvent e);
-
-        /**
-         * The user has performed a down {@link MotionEvent} and not performed
-         * a move or up yet. This event is commonly used to provide visual
-         * feedback to the user to let them know that their action has been
-         * recognized i.e. highlight an element.
-         *
-         * @param e The down motion event
-         */
-        void onShowPress(MotionEvent e);
-
-        /**
-         * Notified when a tap occurs with the up {@link MotionEvent}
-         * that triggered it.
-         *
-         * @param e The up motion event that completed the first tap
-         * @return true if the event is consumed, else false
-         */
-        boolean onSingleTapUp(MotionEvent e);
-
-        /**
-         * Notified when a scroll occurs with the initial on down {@link MotionEvent} and the
-         * current move {@link MotionEvent}. The distance in x and y is also supplied for
-         * convenience.
-         *
-         * @param e1 The first down motion event that started the scrolling.
-         * @param e2 The move motion event that triggered the current onScroll.
-         * @param distanceX The distance along the X axis that has been scrolled since the last
-         *              call to onScroll. This is NOT the distance between {@code e1}
-         *              and {@code e2}.
-         * @param distanceY The distance along the Y axis that has been scrolled since the last
-         *              call to onScroll. This is NOT the distance between {@code e1}
-         *              and {@code e2}.
-         * @return true if the event is consumed, else false
-         */
-        boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY);
-
-        /**
-         * Notified when a long press occurs with the initial on down {@link MotionEvent}
-         * that trigged it.
-         *
-         * @param e The initial on down motion event that started the longpress.
-         */
-        void onLongPress(MotionEvent e);
-
-        /**
-         * Notified of a fling event when it occurs with the initial on down {@link MotionEvent}
-         * and the matching up {@link MotionEvent}. The calculated velocity is supplied along
-         * the x and y axis in pixels per second.
-         *
-         * @param e1 The first down motion event that started the fling.
-         * @param e2 The move motion event that triggered the current onFling.
-         * @param velocityX The velocity of this fling measured in pixels per second
-         *              along the x axis.
-         * @param velocityY The velocity of this fling measured in pixels per second
-         *              along the y axis.
-         * @return true if the event is consumed, else false
-         */
-        boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY);
-    }
-
-    /**
-     * The listener that is used to notify when a double-tap or a confirmed
-     * single-tap occur.
-     */
-    public interface OnDoubleTapListener {
-        /**
-         * Notified when a single-tap occurs.
-         * <p>
-         * Unlike {@link OnGestureListener#onSingleTapUp(MotionEvent)}, this
-         * will only be called after the detector is confident that the user's
-         * first tap is not followed by a second tap leading to a double-tap
-         * gesture.
-         *
-         * @param e The down motion event of the single-tap.
-         * @return true if the event is consumed, else false
-         */
-        boolean onSingleTapConfirmed(MotionEvent e);
- 
-        /**
-         * Notified when a double-tap occurs.
-         *
-         * @param e The down motion event of the first tap of the double-tap.
-         * @return true if the event is consumed, else false
-         */
-        boolean onDoubleTap(MotionEvent e);
-
-        /**
-         * Notified when an event within a double-tap gesture occurs, including
-         * the down, move, and up events.
-         *
-         * @param e The motion event that occurred during the double-tap gesture.
-         * @return true if the event is consumed, else false
-         */
-        boolean onDoubleTapEvent(MotionEvent e);
-    }
-
-    /**
-     * A convenience class to extend when you only want to listen for a subset
-     * of all the gestures. This implements all methods in the
-     * {@link OnGestureListener} and {@link OnDoubleTapListener} but does
-     * nothing and return {@code false} for all applicable methods.
-     */
-    public static class SimpleOnGestureListener implements OnGestureListener, OnDoubleTapListener {
-        public boolean onSingleTapUp(MotionEvent e) {
-            return false;
-        }
-
-        public void onLongPress(MotionEvent e) {
-        }
-
-        public boolean onScroll(MotionEvent e1, MotionEvent e2,
-                float distanceX, float distanceY) {
-            return false;
-        }
-
-        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
-                float velocityY) {
-            return false;
-        }
-
-        public void onShowPress(MotionEvent e) {
-        }
-
-        public boolean onDown(MotionEvent e) {
-            return false;
-        }
-
-        public boolean onDoubleTap(MotionEvent e) {
-            return false;
-        }
-
-        public boolean onDoubleTapEvent(MotionEvent e) {
-            return false;
-        }
-
-        public boolean onSingleTapConfirmed(MotionEvent e) {
-            return false;
-        }
-    }
-
-    private int mTouchSlopSquare;
-    private int mDoubleTapTouchSlopSquare;
-    private int mDoubleTapSlopSquare;
-    private int mMinimumFlingVelocity;
-    private int mMaximumFlingVelocity;
-
-    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();
-
-    // constants for Message.what used by GestureHandler below
-    private static final int SHOW_PRESS = 1;
-    private static final int LONG_PRESS = 2;
-    private static final int TAP = 3;
-
-    private final Handler mHandler;
-    private final OnGestureListener mListener;
-    private OnDoubleTapListener mDoubleTapListener;
-
-    private boolean mStillDown;
-    private boolean mInLongPress;
-    private boolean mAlwaysInTapRegion;
-    private boolean mAlwaysInBiggerTapRegion;
-
-    private MotionEvent mCurrentDownEvent;
-    private MotionEvent mPreviousUpEvent;
-
-    /**
-     * True when the user is still touching for the second tap (down, move, and
-     * up events). Can only be true if there is a double tap listener attached.
-     */
-    private boolean mIsDoubleTapping;
-
-    private float mLastFocusX;
-    private float mLastFocusY;
-    private float mDownFocusX;
-    private float mDownFocusY;
-
-    private boolean mIsLongpressEnabled;
-
-    /**
-     * Determines speed during touch scrolling
-     */
-    private VelocityTracker mVelocityTracker;
-
-    private class GestureHandler extends Handler {
-        GestureHandler() {
-            super();
-        }
-
-        GestureHandler(Handler handler) {
-            super(handler.getLooper());
-        }
-
-        @Override
-        public void handleMessage(Message msg) {
-            switch (msg.what) {
-            case SHOW_PRESS:
-                mListener.onShowPress(mCurrentDownEvent);
-                break;
-                
-            case LONG_PRESS:
-                dispatchLongPress();
-                break;
-                
-            case TAP:
-                // If the user's finger is still down, do not count it as a tap
-                if (mDoubleTapListener != null && !mStillDown) {
-                    mDoubleTapListener.onSingleTapConfirmed(mCurrentDownEvent);
-                }
-                break;
-
-            default:
-                throw new RuntimeException("Unknown message " + msg); //never
-            }
-        }
-    }
-
-    /**
-     * Creates a GestureDetector with the supplied listener.
-     * This variant of the constructor should be used from a non-UI thread 
-     * (as it allows specifying the Handler).
-     * 
-     * @param listener the listener invoked for all the callbacks, this must
-     * not be null.
-     * @param handler the handler to use
-     *
-     * @throws NullPointerException if either {@code listener} or
-     * {@code handler} is null.
-     *
-     * @deprecated Use {@link #GestureDetector(android.content.Context,
-     *      android.view.GestureDetector.OnGestureListener, android.os.Handler)} instead.
-     */
-    @Deprecated
-    public GestureDetector(OnGestureListener listener, Handler handler) {
-        this(null, listener, handler);
-    }
-
-    /**
-     * Creates a GestureDetector with the supplied listener.
-     * You may only use this constructor from a UI thread (this is the usual situation).
-     * @see android.os.Handler#Handler()
-     * 
-     * @param listener the listener invoked for all the callbacks, this must
-     * not be null.
-     * 
-     * @throws NullPointerException if {@code listener} is null.
-     *
-     * @deprecated Use {@link #GestureDetector(android.content.Context,
-     *      android.view.GestureDetector.OnGestureListener)} instead.
-     */
-    @Deprecated
-    public GestureDetector(OnGestureListener listener) {
-        this(null, listener, null);
-    }
-
-    /**
-     * Creates a GestureDetector with the supplied listener.
-     * You may only use this constructor from a UI thread (this is the usual situation).
-     * @see android.os.Handler#Handler()
-     *
-     * @param context the application's context
-     * @param listener the listener invoked for all the callbacks, this must
-     * not be null.
-     *
-     * @throws NullPointerException if {@code listener} is null.
-     */
-    public GestureDetector(Context context, OnGestureListener listener) {
-        this(context, listener, null);
-    }
-
-    /**
-     * Creates a GestureDetector with the supplied listener.
-     * You may only use this constructor from a UI thread (this is the usual situation).
-     * @see android.os.Handler#Handler()
-     *
-     * @param context the application's context
-     * @param listener the listener invoked for all the callbacks, this must
-     * not be null.
-     * @param handler the handler to use     
-     *
-     * @throws NullPointerException if {@code listener} is null.
-     */
-    public GestureDetector(Context context, OnGestureListener listener, Handler handler) {
-        if (handler != null) {
-            mHandler = new GestureHandler(handler);
-        } else {
-            mHandler = new GestureHandler();
-        }
-        mListener = listener;
-        if (listener instanceof OnDoubleTapListener) {
-            setOnDoubleTapListener((OnDoubleTapListener) listener);
-        }
-        init(context);
-    }
-    
-    /**
-     * Creates a GestureDetector with the supplied listener.
-     * You may only use this constructor from a UI thread (this is the usual situation).
-     * @see android.os.Handler#Handler()
-     *
-     * @param context the application's context
-     * @param listener the listener invoked for all the callbacks, this must
-     * not be null.
-     * @param handler the handler to use
-     *
-     * @throws NullPointerException if {@code listener} is null.
-     */
-    public GestureDetector(Context context, OnGestureListener listener, Handler handler,
-            boolean unused) {
-        this(context, listener, handler);
-    }
-
-    private void init(Context context) {
-        if (mListener == null) {
-            throw new NullPointerException("OnGestureListener must not be null");
-        }
-        mIsLongpressEnabled = true;
-
-        // Fallback to support pre-donuts releases
-        int touchSlop, doubleTapSlop, doubleTapTouchSlop;
-        final ViewConfiguration configuration = ViewConfiguration.get(context);
-        touchSlop = configuration.getScaledTouchSlop();
-        doubleTapTouchSlop = configuration.getScaledTouchSlop();
-        doubleTapSlop = configuration.getScaledDoubleTapSlop();
-        mMinimumFlingVelocity = configuration.getScaledMinimumFlingVelocity();
-        mMaximumFlingVelocity = configuration.getScaledMaximumFlingVelocity();
-        mTouchSlopSquare = touchSlop * touchSlop;
-        mDoubleTapTouchSlopSquare = doubleTapTouchSlop * doubleTapTouchSlop;
-        mDoubleTapSlopSquare = doubleTapSlop * doubleTapSlop;
-    }
-
-    /**
-     * Sets the listener which will be called for double-tap and related
-     * gestures.
-     * 
-     * @param onDoubleTapListener the listener invoked for all the callbacks, or
-     *        null to stop listening for double-tap gestures.
-     */
-    public void setOnDoubleTapListener(OnDoubleTapListener onDoubleTapListener) {
-        mDoubleTapListener = onDoubleTapListener;
-    }
-
-    /**
-     * Set whether longpress is enabled, if this is enabled when a user
-     * presses and holds down you get a longpress event and nothing further.
-     * If it's disabled the user can press and hold down and then later
-     * moved their finger and you will get scroll events. By default
-     * longpress is enabled.
-     *
-     * @param isLongpressEnabled whether longpress should be enabled.
-     */
-    public void setIsLongpressEnabled(boolean isLongpressEnabled) {
-        mIsLongpressEnabled = isLongpressEnabled;
-    }
-
-    /**
-     * @return true if longpress is enabled, else false.
-     */
-    public boolean isLongpressEnabled() {
-        return mIsLongpressEnabled;
-    }
-
-    /**
-     * Analyzes the given motion event and if applicable triggers the
-     * appropriate callbacks on the {@link OnGestureListener} supplied.
-     *
-     * @param ev The current motion event.
-     * @return true if the {@link OnGestureListener} consumed the event,
-     *              else false.
-     */
-    public boolean onTouchEvent(MotionEvent ev) {
-        final int action = ev.getAction();
-
-        if (mVelocityTracker == null) {
-            mVelocityTracker = VelocityTracker.obtain();
-        }
-        mVelocityTracker.addMovement(ev);
-
-        final boolean pointerUp =
-                (action & MotionEvent.ACTION_MASK) == MotionEvent.ACTION_POINTER_UP;
-        final int skipIndex = pointerUp ? ev.getActionIndex() : -1;
-
-        // Determine focal point
-        float sumX = 0, sumY = 0;
-        final int count = ev.getPointerCount();
-        for (int i = 0; i < count; i++) {
-            if (skipIndex == i) continue;
-            sumX += ev.getX(i);
-            sumY += ev.getY(i);
-        }
-        final int div = pointerUp ? count - 1 : count;
-        final float focusX = sumX / div;
-        final float focusY = sumY / div;
-
-        boolean handled = false;
-
-        switch (action & MotionEvent.ACTION_MASK) {
-        case MotionEvent.ACTION_POINTER_DOWN:
-            mDownFocusX = mLastFocusX = focusX;
-            mDownFocusY = mLastFocusY = focusY;
-            // Cancel long press and taps
-            cancelTaps();
-            break;
-
-        case MotionEvent.ACTION_POINTER_UP:
-            mDownFocusX = mLastFocusX = focusX;
-            mDownFocusY = mLastFocusY = focusY;
-
-            // Check the dot product of current velocities.
-            // If the pointer that left was opposing another velocity vector, clear.
-            mVelocityTracker.computeCurrentVelocity(1000, mMaximumFlingVelocity);
-            final int upIndex = ev.getActionIndex();
-            final int id1 = ev.getPointerId(upIndex);
-            final float x1 = mVelocityTracker.getXVelocity(id1);
-            final float y1 = mVelocityTracker.getYVelocity(id1);
-            for (int i = 0; i < count; i++) {
-                if (i == upIndex) continue;
-
-                final int id2 = ev.getPointerId(i);
-                final float x = x1 * mVelocityTracker.getXVelocity(id2);
-                final float y = y1 * mVelocityTracker.getYVelocity(id2);
-
-                final float dot = x + y;
-                if (dot < 0) {
-                    mVelocityTracker.clear();
-                    break;
-                }
-            }
-            break;
-
-        case MotionEvent.ACTION_DOWN:
-            if (mDoubleTapListener != null) {
-                boolean hadTapMessage = mHandler.hasMessages(TAP);
-                if (hadTapMessage) mHandler.removeMessages(TAP);
-                if ((mCurrentDownEvent != null) && (mPreviousUpEvent != null) && hadTapMessage &&
-                        isConsideredDoubleTap(mCurrentDownEvent, mPreviousUpEvent, ev)) {
-                    // This is a second tap
-                    mIsDoubleTapping = true;
-                    // Give a callback with the first tap of the double-tap
-                    handled |= mDoubleTapListener.onDoubleTap(mCurrentDownEvent);
-                    // Give a callback with down event of the double-tap
-                    handled |= mDoubleTapListener.onDoubleTapEvent(ev);
-                } else {
-                    // This is a first tap
-                    mHandler.sendEmptyMessageDelayed(TAP, DOUBLE_TAP_TIMEOUT);
-                }
-            }
-
-            mDownFocusX = mLastFocusX = focusX;
-            mDownFocusY = mLastFocusY = focusY;
-            if (mCurrentDownEvent != null) {
-                mCurrentDownEvent.recycle();
-            }
-            mCurrentDownEvent = MotionEvent.obtain(ev);
-            mAlwaysInTapRegion = true;
-            mAlwaysInBiggerTapRegion = true;
-            mStillDown = true;
-            mInLongPress = false;
-            
-            if (mIsLongpressEnabled) {
-                mHandler.removeMessages(LONG_PRESS);
-                mHandler.sendEmptyMessageAtTime(LONG_PRESS, mCurrentDownEvent.getDownTime()
-                        + TAP_TIMEOUT + LONGPRESS_TIMEOUT);
-            }
-            mHandler.sendEmptyMessageAtTime(SHOW_PRESS, mCurrentDownEvent.getDownTime() + TAP_TIMEOUT);
-            handled |= mListener.onDown(ev);
-            break;
-
-        case MotionEvent.ACTION_MOVE:
-            if (mInLongPress) {
-                break;
-            }
-            final float scrollX = mLastFocusX - focusX;
-            final float scrollY = mLastFocusY - focusY;
-            if (mIsDoubleTapping) {
-                // Give the move events of the double-tap
-                handled |= mDoubleTapListener.onDoubleTapEvent(ev);
-            } else if (mAlwaysInTapRegion) {
-                final int deltaX = (int) (focusX - mDownFocusX);
-                final int deltaY = (int) (focusY - mDownFocusY);
-                int distance = (deltaX * deltaX) + (deltaY * deltaY);
-                if (distance > mTouchSlopSquare) {
-                    handled = mListener.onScroll(mCurrentDownEvent, ev, scrollX, scrollY);
-                    mLastFocusX = focusX;
-                    mLastFocusY = focusY;
-                    mAlwaysInTapRegion = false;
-                    mHandler.removeMessages(TAP);
-                    mHandler.removeMessages(SHOW_PRESS);
-                    mHandler.removeMessages(LONG_PRESS);
-                }
-                if (distance > mDoubleTapTouchSlopSquare) {
-                    mAlwaysInBiggerTapRegion = false;
-                }
-            } else if ((Math.abs(scrollX) >= 1) || (Math.abs(scrollY) >= 1)) {
-                handled = mListener.onScroll(mCurrentDownEvent, ev, scrollX, scrollY);
-                mLastFocusX = focusX;
-                mLastFocusY = focusY;
-            }
-            break;
-
-        case MotionEvent.ACTION_UP:
-            mStillDown = false;
-            MotionEvent currentUpEvent = MotionEvent.obtain(ev);
-            if (mIsDoubleTapping) {
-                // Finally, give the up event of the double-tap
-                handled |= mDoubleTapListener.onDoubleTapEvent(ev);
-            } else if (mInLongPress) {
-                mHandler.removeMessages(TAP);
-                mInLongPress = false;
-            } else if (mAlwaysInTapRegion) {
-                handled = mListener.onSingleTapUp(ev);
-            } else {
-
-                // A fling must travel the minimum tap distance
-                final VelocityTracker velocityTracker = mVelocityTracker;
-                final int pointerId = ev.getPointerId(0);
-                velocityTracker.computeCurrentVelocity(1000, mMaximumFlingVelocity);
-                final float velocityY = velocityTracker.getYVelocity(pointerId);
-                final float velocityX = velocityTracker.getXVelocity(pointerId);
-
-                if ((Math.abs(velocityY) > mMinimumFlingVelocity)
-                        || (Math.abs(velocityX) > mMinimumFlingVelocity)){
-                    handled = mListener.onFling(mCurrentDownEvent, ev, velocityX, velocityY);
-                }
-            }
-            if (mPreviousUpEvent != null) {
-                mPreviousUpEvent.recycle();
-            }
-            // Hold the event we obtained above - listeners may have changed the original.
-            mPreviousUpEvent = currentUpEvent;
-            if (mVelocityTracker != null) {
-                // This may have been cleared when we called out to the
-                // application above.
-                mVelocityTracker.recycle();
-                mVelocityTracker = null;
-            }
-            mIsDoubleTapping = false;
-            mHandler.removeMessages(SHOW_PRESS);
-            mHandler.removeMessages(LONG_PRESS);
-            break;
-
-        case MotionEvent.ACTION_CANCEL:
-            cancel();
-            break;
-        }
-
-        return handled;
-    }
-
-    private void cancel() {
-        mHandler.removeMessages(SHOW_PRESS);
-        mHandler.removeMessages(LONG_PRESS);
-        mHandler.removeMessages(TAP);
-        mVelocityTracker.recycle();
-        mVelocityTracker = null;
-        mIsDoubleTapping = false;
-        mStillDown = false;
-        mAlwaysInTapRegion = false;
-        mAlwaysInBiggerTapRegion = false;
-        if (mInLongPress) {
-            mInLongPress = false;
-        }
-    }
-
-    private void cancelTaps() {
-        mHandler.removeMessages(SHOW_PRESS);
-        mHandler.removeMessages(LONG_PRESS);
-        mHandler.removeMessages(TAP);
-        mIsDoubleTapping = false;
-        mAlwaysInTapRegion = false;
-        mAlwaysInBiggerTapRegion = false;
-        if (mInLongPress) {
-            mInLongPress = false;
-        }
-    }
-
-    private boolean isConsideredDoubleTap(MotionEvent firstDown, MotionEvent firstUp,
-            MotionEvent secondDown) {
-        if (!mAlwaysInBiggerTapRegion) {
-            return false;
-        }
-
-        if (secondDown.getEventTime() - firstUp.getEventTime() > DOUBLE_TAP_TIMEOUT) {
-            return false;
-        }
-
-        int deltaX = (int) firstDown.getX() - (int) secondDown.getX();
-        int deltaY = (int) firstDown.getY() - (int) secondDown.getY();
-        return (deltaX * deltaX + deltaY * deltaY < mDoubleTapSlopSquare);
-    }
-
-    private void dispatchLongPress() {
-        mHandler.removeMessages(TAP);
-        mInLongPress = true;
-        mListener.onLongPress(mCurrentDownEvent);
-    }
-}
diff --git a/photoviewer/src/com/android/ex/photo/views/PhotoView.java b/photoviewer/src/com/android/ex/photo/views/PhotoView.java
index f697e1d..838a60d 100644
--- a/photoviewer/src/com/android/ex/photo/views/PhotoView.java
+++ b/photoviewer/src/com/android/ex/photo/views/PhotoView.java
@@ -28,7 +28,10 @@ import android.graphics.Paint.Style;
 import android.graphics.Rect;
 import android.graphics.RectF;
 import android.graphics.drawable.BitmapDrawable;
+import android.support.v4.view.GestureDetectorCompat;
 import android.util.AttributeSet;
+import android.view.GestureDetector.OnGestureListener;
+import android.view.GestureDetector.OnDoubleTapListener;
 import android.view.MotionEvent;
 import android.view.ScaleGestureDetector;
 import android.view.View;
@@ -39,8 +42,8 @@ import com.android.ex.photo.fragments.PhotoViewFragment.HorizontallyScrollable;
 /**
  * Layout for the photo list view header.
  */
-public class PhotoView extends View implements GestureDetector.OnGestureListener,
-        GestureDetector.OnDoubleTapListener, ScaleGestureDetector.OnScaleGestureListener,
+public class PhotoView extends View implements OnGestureListener,
+        OnDoubleTapListener, ScaleGestureDetector.OnScaleGestureListener,
         HorizontallyScrollable {
     /** Zoom animation duration; in milliseconds */
     private final static long ZOOM_ANIMATION_DURATION = 300L;
@@ -109,7 +112,7 @@ public class PhotoView extends View implements GestureDetector.OnGestureListener
     private float mMaxInitialScaleFactor;
 
     /** Gesture detector */
-    private GestureDetector mGestureDetector;
+    private GestureDetectorCompat mGestureDetector;
     /** Gesture detector that detects pinch gestures */
     private ScaleGestureDetector mScaleGetureDetector;
     /** An external click listener */
@@ -130,8 +133,6 @@ public class PhotoView extends View implements GestureDetector.OnGestureListener
     private float mMinScale;
     /** Maximum scale to limit scaling to, 0 means no limit. */
     private float mMaxScale;
-    /** When {@code true}, prevents scale end gesture from falsely triggering a fling. */
-    private boolean mFlingDebounce;
 
     // To support translation [i.e. panning]
     /** Runnable that can move the image */
@@ -260,10 +261,7 @@ public class PhotoView extends View implements GestureDetector.OnGestureListener
     @Override
     public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
         if (mTransformsEnabled) {
-            if (!mFlingDebounce) {
-                mTranslateRunnable.start(velocityX, velocityY);
-            }
-            mFlingDebounce = false;
+            mTranslateRunnable.start(velocityX, velocityY);
         }
         return true;
     }
@@ -294,7 +292,6 @@ public class PhotoView extends View implements GestureDetector.OnGestureListener
             mDoubleTapDebounce = true;
             resetTransformations();
         }
-        mFlingDebounce = true;
     }
 
     @Override
@@ -940,12 +937,9 @@ public class PhotoView extends View implements GestureDetector.OnGestureListener
             sCropPaint.setColor(resources.getColor(R.color.photo_crop_highlight_color));
             sCropPaint.setStyle(Style.STROKE);
             sCropPaint.setStrokeWidth(resources.getDimension(R.dimen.photo_crop_stroke_width));
-
-            sHasMultitouchDistinct = context.getPackageManager().hasSystemFeature(
-                    PackageManager.FEATURE_TOUCHSCREEN_MULTITOUCH_DISTINCT);
         }
 
-        mGestureDetector = new GestureDetector(context, this, null, !sHasMultitouchDistinct);
+        mGestureDetector = new GestureDetectorCompat(context, this, null);
         mScaleGetureDetector = new ScaleGestureDetector(context, this);
         mScaleRunnable = new ScaleRunnable(this);
         mTranslateRunnable = new TranslateRunnable(this);