src/com/android/browser/EdgeSwipeController.java - android_packages_apps_Gello - Gitiles

 /*
  * Copyright (c) 2015, The Linux Foundation. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *     * Redistributions of source code must retain the above copyright
  *       notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
  *       copyright notice, this list of conditions and the following
  *       disclaimer in the documentation and/or other materials provided
  *       with the distribution.
  *     * Neither the name of The Linux Foundation nor the names of its
  *       contributors may be used to endorse or promote products derived
  *       from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
  * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

 package com.android.browser;

 import android.graphics.Bitmap;
 import android.graphics.Canvas;
 import android.graphics.ColorMatrix;
 import android.graphics.ColorMatrixColorFilter;
 import android.graphics.Paint;
 import android.os.CountDownTimer;
 import android.support.v4.widget.ViewDragHelper;
 import android.view.View;

 import org.codeaurora.swe.WebHistoryItem;
 import org.codeaurora.swe.WebView;
 import org.codeaurora.swe.util.Activator;
 import org.codeaurora.swe.util.Observable;

 public class EdgeSwipeController extends ViewDragHelper.Callback {
     private ViewDragHelper mDragHelper;
     private int mState = ViewDragHelper.STATE_IDLE;
     private int mFromEdge = ViewDragHelper.EDGE_LEFT;
     private boolean mbNavigated = false;
     private int mOldX = 0;
     private int mOldDx = 0;
     private Observable mPageLoadTarget;
     private Observable mPageLoadObservable;

     private boolean mbCurrBMSynced = false;

     private Tab mActiveTab;
     private TitleBar mTitleBar;

     private static final float mMinAlpha = 0.5f;
     private static final int mMinProgress = 85;
     private static final int mProgressWaitMS = 1000;
     private static final int EDGE_SWIPE_INVALID_INDEX = -2;

     private CountDownTimer mLoadTimer, mCommitTimer;

     private int mCurrIndex = EDGE_SWIPE_INVALID_INDEX;
     private int mPrevIndex;
     private int mNextIndex;
     private int mMaxIndex;

     private EdgeSwipeModel mModel;
     private EdgeSwipeView mView;

     public EdgeSwipeController(View container,
                                int stationaryViewId,
                                int slidingViewId,
                                int slidingViewShadowId,
                                int opacityViewId,
                                int liveViewId,
                                int viewGroupId,
                                BaseUi ui) {
         DraggableFrameLayout viewGroup = (DraggableFrameLayout)
                 container.findViewById(viewGroupId);

         mActiveTab = ui.getActiveTab();
         mTitleBar = ui.getTitleBar();

         mModel = new EdgeSwipeModel(mActiveTab, mTitleBar);
         mView = new EdgeSwipeView(
                 container,
                 stationaryViewId,
                 slidingViewId,
                 slidingViewShadowId,
                 opacityViewId,
                 liveViewId,
                 viewGroupId,
                 mTitleBar);

         mPageLoadTarget = mActiveTab.getTabHistoryUpdateObservable();
         mPageLoadObservable = Activator.activate(
                 new Observable.Observer() {
                     @Override
                     public void onChange(Object... params) {
                         if (mDragHelper == null ||
                                 mPageLoadTarget == null) {
                             return;
                         }

                         synchronized (this) {
                             int index = (int) params[0];
                             if (mState == ViewDragHelper.STATE_IDLE && index == mCurrIndex) {
                                 monitorProgressAtHistoryUpdate(index);
                             }
                         }
                     }
                 },
                 mPageLoadTarget
         );

         mDragHelper = ViewDragHelper.create(viewGroup, 0.5f, this);
         mDragHelper.setEdgeTrackingEnabled(ViewDragHelper.EDGE_LEFT | ViewDragHelper.EDGE_RIGHT);
         viewGroup.setDragHelper(mDragHelper);
     }

     private void swipeSessionCleanup() {
         mView.goLive();
         mModel.cleanup();
         mCurrIndex = EDGE_SWIPE_INVALID_INDEX;
         mState = ViewDragHelper.STATE_IDLE;
     }

     private boolean setState(int curState, int newState) {
         if (mState == curState) {
             mState = newState;
             return true;
         }
         return false;
     }

     public void cleanup() {
         if (mPageLoadObservable != null) {
             mPageLoadObservable.onOff(false);
             synchronized (this) {
                 mDragHelper.cancel();
                 swipeSessionCleanup();
             }
         }
     }

     public void onConfigurationChanged() {
         synchronized (this) {
             swipeSessionCleanup();
         }
     }

     private void showCurrBMInStationaryView() {
         if (!mbCurrBMSynced) {
             Bitmap currBM = mModel.readSnapshot(mCurrIndex);
             if (currBM != null) {
                 mView.setStationaryViewBitmap(currBM, mModel.getColor(mCurrIndex));
                 mbCurrBMSynced = true;
             }
         }
     }

     private void showCurrBMInSlidingView() {
         if (!mbCurrBMSynced) {
             Bitmap currBM = mModel.readSnapshot(mCurrIndex);
             mView.setSlidingViewBitmap(currBM, mModel.getColor(mCurrIndex));
             if (currBM != null) {
                 mbCurrBMSynced = true;
             }
         }
     }

     private Bitmap getGrayscale(Bitmap bitmap)
     {
         if (bitmap == null)
             return null;

         int height = bitmap.getHeight();
         int width = bitmap.getWidth();

         Bitmap gray = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
         Canvas c = new Canvas(gray);
         Paint paint = new Paint();
         ColorMatrix cm = new ColorMatrix();

         cm.setSaturation(0);

         ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);

         paint.setColorFilter(f);

         c.drawBitmap(bitmap, 0, 0, paint);
         return gray;
     }

     private void monitorProgressAtLoad(final int pageIndex) {
         if (mLoadTimer != null) {
             mLoadTimer.cancel();
         }

         mLoadTimer = new CountDownTimer(mProgressWaitMS * 5, mProgressWaitMS) {
             boolean mGrayBM = false;

             public void onTick(long msRemain) {
                 if (msRemain > mProgressWaitMS * 4) {
                     return;
                 }
                 synchronized (this) {
                     if (mTitleBar.getProgressView().getProgressPercent() >= mMinProgress) {
                         if (mState == ViewDragHelper.STATE_IDLE && pageIndex == mCurrIndex) {
                             swipeSessionCleanup();

                         }
                         cancel();
                     } else if(mState == ViewDragHelper.STATE_DRAGGING) {
                         if (mGrayBM) {
                             return;
                         }
                         switch (mFromEdge) {
                             case ViewDragHelper.EDGE_LEFT:
                                 mView.setSlidingViewBitmap(
                                         getGrayscale(getSnapshotOrFavicon(pageIndex)),
                                         mModel.getColor(pageIndex));
                                 mGrayBM = true;
                                 break;
                             case ViewDragHelper.EDGE_RIGHT:
                                 mView.setStationaryViewBitmap(
                                         getGrayscale(getSnapshotOrFavicon(pageIndex)),
                                         mModel.getColor(pageIndex));
                                 mGrayBM = true;
                                 break;
                         }
                     } else {
                         if (mGrayBM) {
                             return;
                         }
                         mView.setStationaryViewBitmap(
                                 getGrayscale(getSnapshotOrFavicon(pageIndex)),
                                 mModel.getColor(pageIndex));
                         mGrayBM = true;
                     }
                 }
             }

             public void onFinish() {
                 mGrayBM = false;
                 synchronized (this) {
                     if (mTitleBar.getProgressView().getProgressPercent() >= mMinProgress) {
                         if (mState == ViewDragHelper.STATE_IDLE && pageIndex == mCurrIndex) {
                             swipeSessionCleanup();
                         }
                         cancel();
                     }
                 }
             }
         }.start();
     }

     private int lastCommittedHistoryIndex() {
         WebView wv = mActiveTab.getWebView();
         if (wv == null || wv.getLastCommittedHistoryIndex() == -1)
             return 0; // WebView is null or No History has been committed for this tab
         else
             return wv.getLastCommittedHistoryIndex();
     }

     private void monitorProgressAtHistoryUpdate(final int pageIndex) {
         if (mCommitTimer != null) {
             mCommitTimer.cancel();
         }

         if (mTitleBar.getProgressView().getProgressPercent() >= mMinProgress
                 && lastCommittedHistoryIndex() == pageIndex) {
             swipeSessionCleanup();
             return;
         }

         mCommitTimer = new CountDownTimer(mProgressWaitMS * 5, mProgressWaitMS) {
             public void onTick(long msRemain) {
                 synchronized (this) {
                     if (mTitleBar.getProgressView().getProgressPercent() >= mMinProgress) {
                         if (mState == ViewDragHelper.STATE_IDLE && pageIndex == mCurrIndex) {
                             swipeSessionCleanup();

                         }
                         cancel();
                     }
                 }
             }

             public void onFinish() {
                 synchronized (this) {
                     if (mState == ViewDragHelper.STATE_IDLE && pageIndex == mCurrIndex) {
                         swipeSessionCleanup();
                     }
                 }
             }
         }.start();
     }

     private boolean isPortrait(Bitmap bitmap) {
         return (bitmap.getHeight() < bitmap.getWidth());
     }

     private Bitmap getSnapshotOrFavicon(int index) {
         Bitmap bm = mModel.readSnapshot(index);
         if (bm == null || mView.isPortrait() != isPortrait(bm))  {
             WebHistoryItem item = mActiveTab.getWebView()
                     .copyBackForwardList().getItemAtIndex(index);
             if (item != null) {
                 bm = item.getFavicon();
             }
         }
         return bm;
     }

     public void onViewDragStateChanged(int state) {
         synchronized (this) {
             if (mState != ViewDragHelper.STATE_SETTLING || state != ViewDragHelper.STATE_IDLE) {
                 return;
             }

             mView.hideSlidingViews();

             if (mbNavigated) {
                 mView.setStationaryViewBitmap(getSnapshotOrFavicon(mCurrIndex),
                         mModel.getColor(mCurrIndex));
             } else {
                 swipeSessionCleanup();
             }

             mView.setStationaryViewAlpha(1.0f);
             mView.invalidate();

             setState(ViewDragHelper.STATE_SETTLING, ViewDragHelper.STATE_IDLE);
         }
     }

     public void onViewReleased(View releasedChild, float xvel, float yvel) {
         synchronized (this) {
             if (!setState(ViewDragHelper.STATE_DRAGGING, ViewDragHelper.STATE_SETTLING)) {
                 mOldX = 0;
                 mOldDx = 0;
                 return;
             }

             mbNavigated = true;

             boolean bCrossedEventHorizon = Math.abs(mOldX) > mView.getWidth() / 2;

             if (mCurrIndex >= 0) {
                 if ((xvel > 0 || (xvel == 0 && mOldX > 0 && bCrossedEventHorizon))
                         && mFromEdge == ViewDragHelper.EDGE_LEFT
                         && mActiveTab.getWebView().canGoToHistoryIndex(mCurrIndex - 1)) {
                     mCurrIndex -= 1;
                     mActiveTab.getWebView().stopLoading();
                     mActiveTab.getWebView().goToHistoryIndex(mCurrIndex);
                     monitorProgressAtLoad(mCurrIndex);
                     mDragHelper.settleCapturedViewAt(
                             releasedChild.getMeasuredWidth(),
                             releasedChild.getTop());
                 } else if ((xvel < 0 || (xvel == 0 && mOldX < 0 && bCrossedEventHorizon))
                         && mFromEdge == ViewDragHelper.EDGE_RIGHT
                         && mActiveTab.getWebView().canGoToHistoryIndex(mCurrIndex + 1)) {
                     mCurrIndex += 1;
                     mActiveTab.getWebView().stopLoading();
                     mActiveTab.getWebView().goToHistoryIndex(mCurrIndex);
                     monitorProgressAtLoad(mCurrIndex);
                     mDragHelper.settleCapturedViewAt(
                             -releasedChild.getMeasuredWidth(),
                             releasedChild.getTop());
                     mView.goDormant();
                 } else {
                     mbNavigated = false;
                     mDragHelper.settleCapturedViewAt(0, releasedChild.getTop());
                 }
             }
             mOldX = 0;
             mOldDx = 0;

             mView.invalidate();
         }
     }

     public void onViewPositionChanged(View changedView, int left, int top, int dx, int dy) {
         float alpha = ((float) Math.abs(left)) / mView.getMeasuredWidth();

         synchronized (this) {
             switch (mFromEdge) {
                 case ViewDragHelper.EDGE_LEFT:
                     if (mView.isLive()) {
                         return;
                     }
                     mView.setStationaryViewAlpha(mMinAlpha + alpha * (1 - mMinAlpha));

                     if (mState != ViewDragHelper.STATE_IDLE) {
                         mView.moveShadowView(left);
                     }

                     showCurrBMInSlidingView();

                     if (mPrevIndex >= 0) {
                         if (!mView.stationaryViewHasImage()) {
                             mView.setStationaryViewBitmap(getSnapshotOrFavicon(mPrevIndex),
                                     mModel.getColor(mPrevIndex));
                         }
                     }
                     break;
                 case ViewDragHelper.EDGE_RIGHT:
                     mView.setStationaryViewAlpha(mMinAlpha + (1 - alpha) * (1 - mMinAlpha));
                     if (mState != ViewDragHelper.STATE_IDLE) {
                         mView.moveShadowView(mView.getMeasuredWidth() + left);

                         if (!mView.slidingViewHasImage() && mNextIndex < mMaxIndex) {
                             mView.setSlidingViewBitmap(getSnapshotOrFavicon(mNextIndex),
                                     mModel.getColor(mNextIndex));
                         }

                         showCurrBMInStationaryView();
                         if (mbCurrBMSynced) {
                             mView.goDormant();
                         }
                     }
                     break;
                 default:
                     break;
             }
         }
     }

     public void onEdgeDragStarted(int edgeFlags, int pointerId) {
         synchronized (this) {
             if (mActiveTab.isPrivateBrowsingEnabled()) {
                 mDragHelper.abort();
                 return;
             }

             if (mDragHelper.getViewDragState() != ViewDragHelper.STATE_IDLE ||
                     !setState(ViewDragHelper.STATE_IDLE, ViewDragHelper.STATE_DRAGGING)) {
                 mDragHelper.abort();
                 return;
             }

             if ((edgeFlags & mFromEdge) != mFromEdge || mCurrIndex == EDGE_SWIPE_INVALID_INDEX) {
                 onEdgeTouched(edgeFlags, pointerId);
             }

             mbCurrBMSynced = false;

             switch (mFromEdge) {
                 case ViewDragHelper.EDGE_LEFT:
                     mView.showSlidingViews();
                     mView.goDormant();
                     mPrevIndex = mCurrIndex - 1;
                     mView.setStationaryViewBitmap(getSnapshotOrFavicon(mPrevIndex),
                             mModel.getColor(mPrevIndex));
                     showCurrBMInSlidingView();
                     break;
                 case ViewDragHelper.EDGE_RIGHT:
                     mView.showSlidingViews();
                     mNextIndex = mCurrIndex + 1;
                     mView.setSlidingViewBitmap(getSnapshotOrFavicon(mNextIndex),
                             mModel.getColor(mNextIndex));
                     showCurrBMInStationaryView();
                     if (mbCurrBMSynced)
                         mView.goDormant();
                     break;
                 default:
                     break;
             }
         }
     }

     public int getOrderedChildIndex(int index) {
         return mView.slidingViewIndex();
     }

     public void onEdgeTouched (int edgeFlags, int pointerId) {
         synchronized (this) {
             if (mActiveTab.getWebView() == null ||
                 mActiveTab.isPrivateBrowsingEnabled() ||
                 mActiveTab.isKeyboardShowing()) {
                 mDragHelper.abort();
                 return;
             }

             if (mState != ViewDragHelper.STATE_IDLE && mCurrIndex != EDGE_SWIPE_INVALID_INDEX) {
                 mDragHelper.abort();
                 return;
             }

             mView.init();

             if (mCurrIndex == EDGE_SWIPE_INVALID_INDEX) {
                 mCurrIndex = lastCommittedHistoryIndex();
             }

             mMaxIndex = mActiveTab.getWebView().copyBackForwardList().getSize() - 1;
             mModel.updateSnapshot(mCurrIndex);

             if (ViewDragHelper.EDGE_LEFT == (edgeFlags & ViewDragHelper.EDGE_LEFT)) {
                 mFromEdge = ViewDragHelper.EDGE_LEFT;
                 mView.slidingViewTouched(mFromEdge);
                 if (mCurrIndex > 0) {
                     mModel.fetchSnapshot(mCurrIndex - 1);
                 }
             } else if (ViewDragHelper.EDGE_RIGHT == (edgeFlags & ViewDragHelper.EDGE_RIGHT)) {
                 mFromEdge = ViewDragHelper.EDGE_RIGHT;
                 mView.slidingViewTouched(mFromEdge);
                 if (mCurrIndex < mMaxIndex) {
                     mModel.fetchSnapshot(mCurrIndex + 1);
                 }
             }
         }
     }

     public int getViewHorizontalDragRange(View child) {
         return child.getMeasuredWidth();
     }

     public boolean tryCaptureView(View child, int pointerId) {
         return (mState == ViewDragHelper.STATE_DRAGGING && mView.allowCapture(child));
     }

     public int clampViewPositionHorizontal(View child, int left, int dx) {
         if (mOldX != 0 && Math.signum(dx) != Math.signum(mOldDx)) {
             mOldDx = dx;
             return mOldX;
         }

         switch (mFromEdge) {
             case ViewDragHelper.EDGE_LEFT:
                 if (left < 0) {
                     mOldDx = dx;
                     return mOldX;
                 }
                 if (!mActiveTab.getWebView().canGoToHistoryIndex(mPrevIndex)) {
                     if (Math.abs(left) >= child.getMeasuredWidth() / 3) {
                         return child.getMeasuredWidth() / 3;
                     }
                 }
                 break;
             case ViewDragHelper.EDGE_RIGHT:
                 if (left > 0) {
                     mOldDx = dx;
                     return mOldX;
                 }
                 if (!mActiveTab.getWebView().canGoToHistoryIndex(mNextIndex)) {
                     if (Math.abs(left) >= child.getMeasuredWidth() / 3) {
                         return -child.getMeasuredWidth() / 3;
                     }
                 }
                 break;
             default:
                 break;
         }

         mOldX = left;
         mOldDx = dx;
         return left;
     }
 }
	/*
	* Copyright (c) 2015, The Linux Foundation. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are
	* met:
	* * Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* * Redistributions in binary form must reproduce the above
	* copyright notice, this list of conditions and the following
	* disclaimer in the documentation and/or other materials provided
	* with the distribution.
	* * Neither the name of The Linux Foundation nor the names of its
	* contributors may be used to endorse or promote products derived
	* from this software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
	* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
	* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
	* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
	* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
	* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
	* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	package com.android.browser;

	import android.graphics.Bitmap;
	import android.graphics.Canvas;
	import android.graphics.ColorMatrix;
	import android.graphics.ColorMatrixColorFilter;
	import android.graphics.Paint;
	import android.os.CountDownTimer;
	import android.support.v4.widget.ViewDragHelper;
	import android.view.View;

	import org.codeaurora.swe.WebHistoryItem;
	import org.codeaurora.swe.WebView;
	import org.codeaurora.swe.util.Activator;
	import org.codeaurora.swe.util.Observable;

	public class EdgeSwipeController extends ViewDragHelper.Callback {
	private ViewDragHelper mDragHelper;
	private int mState = ViewDragHelper.STATE_IDLE;
	private int mFromEdge = ViewDragHelper.EDGE_LEFT;
	private boolean mbNavigated = false;
	private int mOldX = 0;
	private int mOldDx = 0;
	private Observable mPageLoadTarget;
	private Observable mPageLoadObservable;

	private boolean mbCurrBMSynced = false;

	private Tab mActiveTab;
	private TitleBar mTitleBar;

	private static final float mMinAlpha = 0.5f;
	private static final int mMinProgress = 85;
	private static final int mProgressWaitMS = 1000;
	private static final int EDGE_SWIPE_INVALID_INDEX = -2;

	private CountDownTimer mLoadTimer, mCommitTimer;

	private int mCurrIndex = EDGE_SWIPE_INVALID_INDEX;
	private int mPrevIndex;
	private int mNextIndex;
	private int mMaxIndex;

	private EdgeSwipeModel mModel;
	private EdgeSwipeView mView;

	public EdgeSwipeController(View container,
	int stationaryViewId,
	int slidingViewId,
	int slidingViewShadowId,
	int opacityViewId,
	int liveViewId,
	int viewGroupId,
	BaseUi ui) {
	DraggableFrameLayout viewGroup = (DraggableFrameLayout)
	container.findViewById(viewGroupId);

	mActiveTab = ui.getActiveTab();
	mTitleBar = ui.getTitleBar();

	mModel = new EdgeSwipeModel(mActiveTab, mTitleBar);
	mView = new EdgeSwipeView(
	container,
	stationaryViewId,
	slidingViewId,
	slidingViewShadowId,
	opacityViewId,
	liveViewId,
	viewGroupId,
	mTitleBar);

	mPageLoadTarget = mActiveTab.getTabHistoryUpdateObservable();
	mPageLoadObservable = Activator.activate(
	new Observable.Observer() {
	@Override
	public void onChange(Object... params) {
	if (mDragHelper == null \|\|
	mPageLoadTarget == null) {
	return;
	}

	synchronized (this) {
	int index = (int) params[0];
	if (mState == ViewDragHelper.STATE_IDLE && index == mCurrIndex) {
	monitorProgressAtHistoryUpdate(index);
	}
	}
	}
	},
	mPageLoadTarget
	);

	mDragHelper = ViewDragHelper.create(viewGroup, 0.5f, this);
	mDragHelper.setEdgeTrackingEnabled(ViewDragHelper.EDGE_LEFT \| ViewDragHelper.EDGE_RIGHT);
	viewGroup.setDragHelper(mDragHelper);
	}

	private void swipeSessionCleanup() {
	mView.goLive();
	mModel.cleanup();
	mCurrIndex = EDGE_SWIPE_INVALID_INDEX;
	mState = ViewDragHelper.STATE_IDLE;
	}

	private boolean setState(int curState, int newState) {
	if (mState == curState) {
	mState = newState;
	return true;
	}
	return false;
	}

	public void cleanup() {
	if (mPageLoadObservable != null) {
	mPageLoadObservable.onOff(false);
	synchronized (this) {
	mDragHelper.cancel();
	swipeSessionCleanup();
	}
	}
	}

	public void onConfigurationChanged() {
	synchronized (this) {
	swipeSessionCleanup();
	}
	}

	private void showCurrBMInStationaryView() {
	if (!mbCurrBMSynced) {
	Bitmap currBM = mModel.readSnapshot(mCurrIndex);
	if (currBM != null) {
	mView.setStationaryViewBitmap(currBM, mModel.getColor(mCurrIndex));
	mbCurrBMSynced = true;
	}
	}
	}

	private void showCurrBMInSlidingView() {
	if (!mbCurrBMSynced) {
	Bitmap currBM = mModel.readSnapshot(mCurrIndex);
	mView.setSlidingViewBitmap(currBM, mModel.getColor(mCurrIndex));
	if (currBM != null) {
	mbCurrBMSynced = true;
	}
	}
	}

	private Bitmap getGrayscale(Bitmap bitmap)
	{
	if (bitmap == null)
	return null;

	int height = bitmap.getHeight();
	int width = bitmap.getWidth();

	Bitmap gray = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
	Canvas c = new Canvas(gray);
	Paint paint = new Paint();
	ColorMatrix cm = new ColorMatrix();

	cm.setSaturation(0);

	ColorMatrixColorFilter f = new ColorMatrixColorFilter(cm);

	paint.setColorFilter(f);

	c.drawBitmap(bitmap, 0, 0, paint);
	return gray;
	}

	private void monitorProgressAtLoad(final int pageIndex) {
	if (mLoadTimer != null) {
	mLoadTimer.cancel();
	}

	mLoadTimer = new CountDownTimer(mProgressWaitMS * 5, mProgressWaitMS) {
	boolean mGrayBM = false;

	public void onTick(long msRemain) {
	if (msRemain > mProgressWaitMS * 4) {
	return;
	}
	synchronized (this) {
	if (mTitleBar.getProgressView().getProgressPercent() >= mMinProgress) {
	if (mState == ViewDragHelper.STATE_IDLE && pageIndex == mCurrIndex) {
	swipeSessionCleanup();

	}
	cancel();
	} else if(mState == ViewDragHelper.STATE_DRAGGING) {
	if (mGrayBM) {
	return;
	}
	switch (mFromEdge) {
	case ViewDragHelper.EDGE_LEFT:
	mView.setSlidingViewBitmap(
	getGrayscale(getSnapshotOrFavicon(pageIndex)),
	mModel.getColor(pageIndex));
	mGrayBM = true;
	break;
	case ViewDragHelper.EDGE_RIGHT:
	mView.setStationaryViewBitmap(
	getGrayscale(getSnapshotOrFavicon(pageIndex)),
	mModel.getColor(pageIndex));
	mGrayBM = true;
	break;
	}
	} else {
	if (mGrayBM) {
	return;
	}
	mView.setStationaryViewBitmap(
	getGrayscale(getSnapshotOrFavicon(pageIndex)),
	mModel.getColor(pageIndex));
	mGrayBM = true;
	}
	}
	}

	public void onFinish() {
	mGrayBM = false;
	synchronized (this) {
	if (mTitleBar.getProgressView().getProgressPercent() >= mMinProgress) {
	if (mState == ViewDragHelper.STATE_IDLE && pageIndex == mCurrIndex) {
	swipeSessionCleanup();
	}
	cancel();
	}
	}
	}
	}.start();
	}

	private int lastCommittedHistoryIndex() {
	WebView wv = mActiveTab.getWebView();
	if (wv == null \|\| wv.getLastCommittedHistoryIndex() == -1)
	return 0; // WebView is null or No History has been committed for this tab
	else
	return wv.getLastCommittedHistoryIndex();
	}

	private void monitorProgressAtHistoryUpdate(final int pageIndex) {
	if (mCommitTimer != null) {
	mCommitTimer.cancel();
	}

	if (mTitleBar.getProgressView().getProgressPercent() >= mMinProgress
	&& lastCommittedHistoryIndex() == pageIndex) {
	swipeSessionCleanup();
	return;
	}

	mCommitTimer = new CountDownTimer(mProgressWaitMS * 5, mProgressWaitMS) {
	public void onTick(long msRemain) {
	synchronized (this) {
	if (mTitleBar.getProgressView().getProgressPercent() >= mMinProgress) {
	if (mState == ViewDragHelper.STATE_IDLE && pageIndex == mCurrIndex) {
	swipeSessionCleanup();

	}
	cancel();
	}
	}
	}

	public void onFinish() {
	synchronized (this) {
	if (mState == ViewDragHelper.STATE_IDLE && pageIndex == mCurrIndex) {
	swipeSessionCleanup();
	}
	}
	}
	}.start();
	}

	private boolean isPortrait(Bitmap bitmap) {
	return (bitmap.getHeight() < bitmap.getWidth());
	}

	private Bitmap getSnapshotOrFavicon(int index) {
	Bitmap bm = mModel.readSnapshot(index);
	if (bm == null \|\| mView.isPortrait() != isPortrait(bm)) {
	WebHistoryItem item = mActiveTab.getWebView()
	.copyBackForwardList().getItemAtIndex(index);
	if (item != null) {
	bm = item.getFavicon();
	}
	}
	return bm;
	}

	public void onViewDragStateChanged(int state) {
	synchronized (this) {
	if (mState != ViewDragHelper.STATE_SETTLING \|\| state != ViewDragHelper.STATE_IDLE) {
	return;
	}

	mView.hideSlidingViews();

	if (mbNavigated) {
	mView.setStationaryViewBitmap(getSnapshotOrFavicon(mCurrIndex),
	mModel.getColor(mCurrIndex));
	} else {
	swipeSessionCleanup();
	}

	mView.setStationaryViewAlpha(1.0f);
	mView.invalidate();

	setState(ViewDragHelper.STATE_SETTLING, ViewDragHelper.STATE_IDLE);
	}
	}

	public void onViewReleased(View releasedChild, float xvel, float yvel) {
	synchronized (this) {
	if (!setState(ViewDragHelper.STATE_DRAGGING, ViewDragHelper.STATE_SETTLING)) {
	mOldX = 0;
	mOldDx = 0;
	return;
	}

	mbNavigated = true;

	boolean bCrossedEventHorizon = Math.abs(mOldX) > mView.getWidth() / 2;

	if (mCurrIndex >= 0) {
	if ((xvel > 0 \|\| (xvel == 0 && mOldX > 0 && bCrossedEventHorizon))
	&& mFromEdge == ViewDragHelper.EDGE_LEFT
	&& mActiveTab.getWebView().canGoToHistoryIndex(mCurrIndex - 1)) {
	mCurrIndex -= 1;
	mActiveTab.getWebView().stopLoading();
	mActiveTab.getWebView().goToHistoryIndex(mCurrIndex);
	monitorProgressAtLoad(mCurrIndex);
	mDragHelper.settleCapturedViewAt(
	releasedChild.getMeasuredWidth(),
	releasedChild.getTop());
	} else if ((xvel < 0 \|\| (xvel == 0 && mOldX < 0 && bCrossedEventHorizon))
	&& mFromEdge == ViewDragHelper.EDGE_RIGHT
	&& mActiveTab.getWebView().canGoToHistoryIndex(mCurrIndex + 1)) {
	mCurrIndex += 1;
	mActiveTab.getWebView().stopLoading();
	mActiveTab.getWebView().goToHistoryIndex(mCurrIndex);
	monitorProgressAtLoad(mCurrIndex);
	mDragHelper.settleCapturedViewAt(
	-releasedChild.getMeasuredWidth(),
	releasedChild.getTop());
	mView.goDormant();
	} else {
	mbNavigated = false;
	mDragHelper.settleCapturedViewAt(0, releasedChild.getTop());
	}
	}
	mOldX = 0;
	mOldDx = 0;

	mView.invalidate();
	}
	}

	public void onViewPositionChanged(View changedView, int left, int top, int dx, int dy) {
	float alpha = ((float) Math.abs(left)) / mView.getMeasuredWidth();

	synchronized (this) {
	switch (mFromEdge) {
	case ViewDragHelper.EDGE_LEFT:
	if (mView.isLive()) {
	return;
	}
	mView.setStationaryViewAlpha(mMinAlpha + alpha * (1 - mMinAlpha));

	if (mState != ViewDragHelper.STATE_IDLE) {
	mView.moveShadowView(left);
	}

	showCurrBMInSlidingView();

	if (mPrevIndex >= 0) {
	if (!mView.stationaryViewHasImage()) {
	mView.setStationaryViewBitmap(getSnapshotOrFavicon(mPrevIndex),
	mModel.getColor(mPrevIndex));
	}
	}
	break;
	case ViewDragHelper.EDGE_RIGHT:
	mView.setStationaryViewAlpha(mMinAlpha + (1 - alpha) * (1 - mMinAlpha));
	if (mState != ViewDragHelper.STATE_IDLE) {
	mView.moveShadowView(mView.getMeasuredWidth() + left);

	if (!mView.slidingViewHasImage() && mNextIndex < mMaxIndex) {
	mView.setSlidingViewBitmap(getSnapshotOrFavicon(mNextIndex),
	mModel.getColor(mNextIndex));
	}

	showCurrBMInStationaryView();
	if (mbCurrBMSynced) {
	mView.goDormant();
	}
	}
	break;
	default:
	break;
	}
	}
	}

	public void onEdgeDragStarted(int edgeFlags, int pointerId) {
	synchronized (this) {
	if (mActiveTab.isPrivateBrowsingEnabled()) {
	mDragHelper.abort();
	return;
	}

	if (mDragHelper.getViewDragState() != ViewDragHelper.STATE_IDLE \|\|
	!setState(ViewDragHelper.STATE_IDLE, ViewDragHelper.STATE_DRAGGING)) {
	mDragHelper.abort();
	return;
	}

	if ((edgeFlags & mFromEdge) != mFromEdge \|\| mCurrIndex == EDGE_SWIPE_INVALID_INDEX) {
	onEdgeTouched(edgeFlags, pointerId);
	}

	mbCurrBMSynced = false;

	switch (mFromEdge) {
	case ViewDragHelper.EDGE_LEFT:
	mView.showSlidingViews();
	mView.goDormant();
	mPrevIndex = mCurrIndex - 1;
	mView.setStationaryViewBitmap(getSnapshotOrFavicon(mPrevIndex),
	mModel.getColor(mPrevIndex));
	showCurrBMInSlidingView();
	break;
	case ViewDragHelper.EDGE_RIGHT:
	mView.showSlidingViews();
	mNextIndex = mCurrIndex + 1;
	mView.setSlidingViewBitmap(getSnapshotOrFavicon(mNextIndex),
	mModel.getColor(mNextIndex));
	showCurrBMInStationaryView();
	if (mbCurrBMSynced)
	mView.goDormant();
	break;
	default:
	break;
	}
	}
	}

	public int getOrderedChildIndex(int index) {
	return mView.slidingViewIndex();
	}

	public void onEdgeTouched (int edgeFlags, int pointerId) {
	synchronized (this) {
	if (mActiveTab.getWebView() == null \|\|
	mActiveTab.isPrivateBrowsingEnabled() \|\|
	mActiveTab.isKeyboardShowing()) {
	mDragHelper.abort();
	return;
	}

	if (mState != ViewDragHelper.STATE_IDLE && mCurrIndex != EDGE_SWIPE_INVALID_INDEX) {
	mDragHelper.abort();
	return;
	}

	mView.init();

	if (mCurrIndex == EDGE_SWIPE_INVALID_INDEX) {
	mCurrIndex = lastCommittedHistoryIndex();
	}

	mMaxIndex = mActiveTab.getWebView().copyBackForwardList().getSize() - 1;
	mModel.updateSnapshot(mCurrIndex);

	if (ViewDragHelper.EDGE_LEFT == (edgeFlags & ViewDragHelper.EDGE_LEFT)) {
	mFromEdge = ViewDragHelper.EDGE_LEFT;
	mView.slidingViewTouched(mFromEdge);
	if (mCurrIndex > 0) {
	mModel.fetchSnapshot(mCurrIndex - 1);
	}
	} else if (ViewDragHelper.EDGE_RIGHT == (edgeFlags & ViewDragHelper.EDGE_RIGHT)) {
	mFromEdge = ViewDragHelper.EDGE_RIGHT;
	mView.slidingViewTouched(mFromEdge);
	if (mCurrIndex < mMaxIndex) {
	mModel.fetchSnapshot(mCurrIndex + 1);
	}
	}
	}
	}

	public int getViewHorizontalDragRange(View child) {
	return child.getMeasuredWidth();
	}

	public boolean tryCaptureView(View child, int pointerId) {
	return (mState == ViewDragHelper.STATE_DRAGGING && mView.allowCapture(child));
	}

	public int clampViewPositionHorizontal(View child, int left, int dx) {
	if (mOldX != 0 && Math.signum(dx) != Math.signum(mOldDx)) {
	mOldDx = dx;
	return mOldX;
	}

	switch (mFromEdge) {
	case ViewDragHelper.EDGE_LEFT:
	if (left < 0) {
	mOldDx = dx;
	return mOldX;
	}
	if (!mActiveTab.getWebView().canGoToHistoryIndex(mPrevIndex)) {
	if (Math.abs(left) >= child.getMeasuredWidth() / 3) {
	return child.getMeasuredWidth() / 3;
	}
	}
	break;
	case ViewDragHelper.EDGE_RIGHT:
	if (left > 0) {
	mOldDx = dx;
	return mOldX;
	}
	if (!mActiveTab.getWebView().canGoToHistoryIndex(mNextIndex)) {
	if (Math.abs(left) >= child.getMeasuredWidth() / 3) {
	return -child.getMeasuredWidth() / 3;
	}
	}
	break;
	default:
	break;
	}

	mOldX = left;
	mOldDx = dx;
	return left;
	}
	}