| // Copyright 2012 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| package org.chromium.content.browser; |
| |
| import android.content.Context; |
| import android.os.Handler; |
| import android.os.Message; |
| import android.view.MotionEvent; |
| import android.view.ViewConfiguration; |
| |
| import java.util.Iterator; |
| |
| /** |
| * This class controls long press timers and is owned by a ContentViewGestureHandler. |
| * |
| * For instance, we may receive a DOWN then UP, so we may need to cancel the |
| * timer before the UP completes its roundtrip from WebKit. |
| */ |
| class LongPressDetector { |
| private MotionEvent mCurrentDownEvent; |
| private final LongPressDelegate mLongPressDelegate; |
| private final Handler mLongPressHandler; |
| private final int mTouchSlopSquare; |
| private boolean mInLongPress; |
| |
| // The following are used when touch events are offered to native, and not for |
| // anything relating to the GestureDetector. |
| // True iff a touch_move has exceeded the touch slop distance. |
| private boolean mMoveConfirmed; |
| // Coordinates of the start of a touch event (i.e. the touch_down). |
| private int mTouchInitialX; |
| private int mTouchInitialY; |
| |
| private static final int LONG_PRESS = 2; |
| |
| private static final int LONGPRESS_TIMEOUT = ViewConfiguration.getLongPressTimeout(); |
| private static final int TAP_TIMEOUT = ViewConfiguration.getTapTimeout(); |
| |
| LongPressDetector(Context context, LongPressDelegate delegate) { |
| mLongPressDelegate = delegate; |
| mLongPressHandler = new LongPressHandler(); |
| final ViewConfiguration configuration = ViewConfiguration.get(context); |
| int touchSlop = configuration.getScaledTouchSlop(); |
| mTouchSlopSquare = touchSlop * touchSlop; |
| } |
| |
| private class LongPressHandler extends Handler { |
| LongPressHandler() { |
| super(); |
| } |
| |
| @Override |
| public void handleMessage(Message msg) { |
| switch (msg.what) { |
| case LONG_PRESS: |
| dispatchLongPress(); |
| break; |
| default: |
| throw new RuntimeException("Unknown message " + msg); // never |
| } |
| } |
| } |
| |
| /** |
| * This is an interface to execute the LongPress when it receives the onLongPress message. |
| */ |
| interface LongPressDelegate { |
| /** |
| * @param event The event will be recycled after this call has returned. |
| */ |
| public void onLongPress(MotionEvent event); |
| } |
| |
| private static long calculateLongPressTimeoutTime(MotionEvent ev) { |
| // Using getEventTime instead of getDownTime since for Android WebView, |
| // event stream can be arbitrarily delayed. |
| return ev.getEventTime() + TAP_TIMEOUT + LONGPRESS_TIMEOUT; |
| } |
| |
| /** |
| * Initiates a LONG_PRESS gesture timer if needed. |
| */ |
| void startLongPressTimerIfNeeded(MotionEvent ev) { |
| if (ev.getAction() != MotionEvent.ACTION_DOWN) return; |
| |
| // If there is a current down, we do not expect another down event before |
| // receiving an up event |
| if (mCurrentDownEvent != null) return; |
| |
| mCurrentDownEvent = MotionEvent.obtain(ev); |
| mLongPressHandler.sendEmptyMessageAtTime(LONG_PRESS, |
| calculateLongPressTimeoutTime(mCurrentDownEvent)); |
| mInLongPress = false; |
| } |
| |
| // Cancel LONG_PRESS timers. |
| void cancelLongPressIfNeeded(MotionEvent ev) { |
| if (!hasPendingMessage() || |
| mCurrentDownEvent == null || ev.getDownTime() != mCurrentDownEvent.getDownTime()) { |
| return; |
| } |
| final int action = ev.getAction(); |
| final float y = ev.getY(); |
| final float x = ev.getX(); |
| switch (action & MotionEvent.ACTION_MASK) { |
| case MotionEvent.ACTION_MOVE: |
| final int deltaX = (int) (x - mCurrentDownEvent.getX()); |
| final int deltaY = (int) (y - mCurrentDownEvent.getY()); |
| int distance = (deltaX * deltaX) + (deltaY * deltaY); |
| if (distance > mTouchSlopSquare) { |
| cancelLongPress(); |
| } |
| break; |
| case MotionEvent.ACTION_UP: |
| case MotionEvent.ACTION_CANCEL: |
| if (calculateLongPressTimeoutTime(mCurrentDownEvent) > ev.getEventTime()) { |
| cancelLongPress(); |
| } |
| break; |
| default: |
| break; |
| } |
| } |
| |
| // Given a stream of pending events, cancel the LONG_PRESS timer if appropriate. |
| void cancelLongPressIfNeeded(Iterator<MotionEvent> pendingEvents) { |
| if (mCurrentDownEvent == null) |
| return; |
| long currentDownTime = mCurrentDownEvent.getDownTime(); |
| while (pendingEvents.hasNext()) { |
| MotionEvent pending = pendingEvents.next(); |
| if (pending.getDownTime() != currentDownTime) { |
| break; |
| } |
| cancelLongPressIfNeeded(pending); |
| } |
| } |
| |
| void cancelLongPress() { |
| mInLongPress = false; |
| if (hasPendingMessage()) { |
| mLongPressHandler.removeMessages(LONG_PRESS); |
| mCurrentDownEvent.recycle(); |
| mCurrentDownEvent = null; |
| } |
| } |
| |
| // Used this to check if a onSingleTapUp is part of a long press event. |
| boolean isInLongPress() { |
| return mInLongPress; |
| } |
| |
| private void dispatchLongPress() { |
| mInLongPress = true; |
| mLongPressDelegate.onLongPress(mCurrentDownEvent); |
| mCurrentDownEvent.recycle(); |
| mCurrentDownEvent = null; |
| } |
| |
| boolean hasPendingMessage() { |
| return mCurrentDownEvent != null; |
| } |
| |
| void onOfferTouchEventToJavaScript(MotionEvent event) { |
| if (event.getActionMasked() == MotionEvent.ACTION_DOWN) { |
| mMoveConfirmed = false; |
| mTouchInitialX = Math.round(event.getX()); |
| mTouchInitialY = Math.round(event.getY()); |
| } |
| } |
| |
| boolean confirmOfferMoveEventToJavaScript(MotionEvent event) { |
| if (!mMoveConfirmed) { |
| int deltaX = Math.round(event.getX()) - mTouchInitialX; |
| int deltaY = Math.round(event.getY()) - mTouchInitialY; |
| if (deltaX * deltaX + deltaY * deltaY >= mTouchSlopSquare) { |
| mMoveConfirmed = true; |
| } |
| } |
| return mMoveConfirmed; |
| } |
| |
| /** |
| * This is for testing only. |
| * Sends a LongPress gesture. This should always be called after a down event. |
| */ |
| void sendLongPressGestureForTest() { |
| if (mCurrentDownEvent == null) return; |
| dispatchLongPress(); |
| } |
| } |