android: upgrade PanZoomController - add configurable zoom limits

Change-Id: I19815f58af4d060cffe515829a2a5472d32bf83c

android/experimental/LOAndroid3/src/java/org/libreoffice/LibreOfficeMainActivity.java

@@ -118,6 +118,7 @@ public class LibreOfficeMainActivity extends Activity {
         }
 
         mLayerController = new LayerController(this);
+        mLayerController.setAllowZoom(true);
         mLayerClient = new GeckoLayerClient(this);
         mLayerController.setLayerClient(mLayerClient);
         mGeckoLayout.addView(mLayerController.getView(), 0);

android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/DisplayPortCalculator.java

@@ -36,7 +36,7 @@ final class DisplayPortCalculator {
     private static final String PREF_DISPLAYPORT_VB_DANGER_Y_INCR = "gfx.displayport.strategy_vb.danger_y_incr";
     private static final String PREF_DISPLAYPORT_PB_VELOCITY_THRESHOLD = "gfx.displayport.strategy_pb.threshold";
 
-    private static DisplayPortStrategy sStrategy = new NoMarginStrategy(null);
+    private static DisplayPortStrategy sStrategy = new DynamicResolutionStrategy(null);
 
     static DisplayPortMetrics calculate(ImmutableViewportMetrics metrics, PointF velocity) {
         return sStrategy.calculate(metrics, (velocity == null ? ZERO_VELOCITY : velocity));

android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/GeckoLayerClient.java

@@ -172,7 +172,7 @@ public class GeckoLayerClient implements LayerView.Listener {
             // Don't adjust page size when zooming unless zoom levels are
             // approximately equal.
             if (FloatUtils.fuzzyEquals(mLayerController.getZoomFactor(), mGeckoViewport.getZoomFactor())) {
-                mLayerController.setPageSize(mGeckoViewport.getPageSize());
+                mLayerController.setPageSize(mGeckoViewport.getPageSize(), mGeckoViewport.getPageSize());
             }
         } else {
             mLayerController.setViewportMetrics(mGeckoViewport);
@@ -254,7 +254,7 @@ public class GeckoLayerClient implements LayerView.Listener {
         float ourZoom = mLayerController.getZoomFactor();
         pageWidth = pageWidth * ourZoom / zoom;
         pageHeight = pageHeight * ourZoom /zoom;
-        mLayerController.setPageSize(new FloatSize(pageWidth, pageHeight));
+        mLayerController.setPageSize(new FloatSize(pageWidth, pageHeight), new FloatSize(pageWidth, pageHeight));
         // Here the page size of the document has changed, but the document being displayed
         // is still the same. Therefore, we don't need to send anything to browser.js; any
         // changes we need to make to the display port will get sent the next time we call
@@ -296,13 +296,13 @@ public class GeckoLayerClient implements LayerView.Listener {
     }
 
     @Override
-    public void compositionResumeRequested() {
+    public void compositionResumeRequested(int width, int height) {
 
     }
 
     @Override
     public void surfaceChanged(int width, int height) {
-        compositionResumeRequested();
+        compositionResumeRequested(width, height);
         renderRequested();
     }
 

android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/LayerController.java

 /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
- * ***** BEGIN LICENSE BLOCK *****
- * Version: MPL 1.1/GPL 2.0/LGPL 2.1
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (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.mozilla.org/MPL/
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- *
- * The Original Code is Mozilla Android code.
- *
- * The Initial Developer of the Original Code is Mozilla Foundation.
- * Portions created by the Initial Developer are Copyright (C) 2009-2010
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- *   Patrick Walton <pcwalton@mozilla.com>
- *   Chris Lord <chrislord.net@gmail.com>
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either the GNU General Public License Version 2 or later (the "GPL"), or
- * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- * in which case the provisions of the GPL or the LGPL are applicable instead
- * of those above. If you wish to allow use of your version of this file only
- * under the terms of either the GPL or the LGPL, and not to allow others to
- * use your version of this file under the terms of the MPL, indicate your
- * decision by deleting the provisions above and replace them with the notice
- * and other provisions required by the GPL or the LGPL. If you do not delete
- * the provisions above, a recipient may use your version of this file under
- * the terms of any one of the MPL, the GPL or the LGPL.
- *
- * ***** END LICENSE BLOCK ***** */
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 package org.mozilla.gecko.gfx;
 
@@ -42,6 +9,7 @@ import android.content.Context;
 import android.content.res.Resources;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
+import android.graphics.Color;
 import android.graphics.PointF;
 import android.graphics.RectF;
 import android.view.GestureDetector;
@@ -49,8 +17,6 @@ import android.view.GestureDetector;
 import org.mozilla.gecko.ui.PanZoomController;
 import org.mozilla.gecko.ui.SimpleScaleGestureDetector;
 
-import java.util.regex.Pattern;
-
 /**
  * The layer controller manages a tile that represents the visible page. It does panning and
  * zooming natively by delegating to a panning/zooming controller. Touch events can be dispatched
@@ -87,12 +53,15 @@ public class LayerController {
     private GeckoLayerClient mLayerClient;          /* The layer client. */
 
     /* The new color for the checkerboard. */
-    private int mCheckerboardColor;
+    private int mCheckerboardColor = Color.WHITE;
     private boolean mCheckerboardShouldShowChecks;
 
-    private boolean mForceRedraw;
+    private boolean mAllowZoom;
+    private float mDefaultZoom;
+    private float mMinZoom;
+    private float mMaxZoom;
 
-    private static Pattern sColorPattern;
+    private boolean mForceRedraw;
 
     public LayerController(Context context) {
         mContext = context;
@@ -124,6 +93,10 @@ public class LayerController {
         return mViewportMetrics.getViewport();
     }
 
+    public RectF getCssViewport() {
+        return mViewportMetrics.getCssViewport();
+    }
+
     public FloatSize getViewportSize() {
         return mViewportMetrics.getSize();
     }
@@ -132,6 +105,10 @@ public class LayerController {
         return mViewportMetrics.getPageSize();
     }
 
+    public FloatSize getCssPageSize() {
+        return mViewportMetrics.getCssPageSize();
+    }
+
     public PointF getOrigin() {
         return mViewportMetrics.getOrigin();
     }
@@ -189,12 +166,12 @@ public class LayerController {
     }
 
     /** Sets the current page size. You must hold the monitor while calling this. */
-    public void setPageSize(FloatSize size) {
-        if (mViewportMetrics.getPageSize().fuzzyEquals(size))
+    public void setPageSize(FloatSize size, FloatSize cssSize) {
+        if (mViewportMetrics.getCssPageSize().equals(cssSize))
             return;
 
         ViewportMetrics viewportMetrics = new ViewportMetrics(mViewportMetrics);
-        viewportMetrics.setPageSize(size, size);
+        viewportMetrics.setPageSize(size, cssSize);
         mViewportMetrics = new ImmutableViewportMetrics(viewportMetrics);
 
         // Page size is owned by the layer client, so no need to notify it of
@@ -294,8 +271,9 @@ public class LayerController {
      * correct.
      */
     public PointF convertViewPointToLayerPoint(PointF viewPoint) {
-        if (mRootLayer == null)
+        if (mLayerClient == null) {
             return null;
+        }
 
         ImmutableViewportMetrics viewportMetrics = mViewportMetrics;
         PointF origin = viewportMetrics.getOrigin();
@@ -337,5 +315,41 @@ public class LayerController {
         mCheckerboardColor = newColor;
         mView.requestRender();
     }
-}
 
+    public void setAllowZoom(final boolean aValue) {
+        mAllowZoom = aValue;
+        mView.post(new Runnable() {
+            public void run() {
+                mView.getTouchEventHandler().setDoubleTapEnabled(aValue);
+            }
+        });
+    }
+
+    public boolean getAllowZoom() {
+        return mAllowZoom;
+    }
+
+    public void setDefaultZoom(float aValue) {
+        mDefaultZoom = aValue;
+    }
+
+    public float getDefaultZoom() {
+        return mDefaultZoom;
+    }
+
+    public void setMinZoom(float aValue) {
+        mMinZoom = aValue;
+    }
+
+    public float getMinZoom() {
+        return mMinZoom;
+    }
+
+    public void setMaxZoom(float aValue) {
+        mMaxZoom = aValue;
+    }
+
+    public float getMaxZoom() {
+        return mMaxZoom;
+    }
+}

android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/LayerView.java

 /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
- * ***** BEGIN LICENSE BLOCK *****
- * Version: MPL 1.1/GPL 2.0/LGPL 2.1
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (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.mozilla.org/MPL/
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- *
- * The Original Code is Mozilla Android code.
- *
- * The Initial Developer of the Original Code is Mozilla Foundation.
- * Portions created by the Initial Developer are Copyright (C) 2009-2010
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- *   Patrick Walton <pcwalton@mozilla.com>
- *   Arkady Blyakher <rkadyb@mit.edu>
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either the GNU General Public License Version 2 or later (the "GPL"), or
- * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- * in which case the provisions of the GPL or the LGPL are applicable instead
- * of those above. If you wish to allow use of your version of this file only
- * under the terms of either the GPL or the LGPL, and not to allow others to
- * use your version of this file under the terms of the MPL, indicate your
- * decision by deleting the provisions above and replace them with the notice
- * and other provisions required by the GPL or the LGPL. If you do not delete
- * the provisions above, a recipient may use your version of this file under
- * the terms of any one of the MPL, the GPL or the LGPL.
- *
- * ***** END LICENSE BLOCK ***** */
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 package org.mozilla.gecko.gfx;
 
@@ -42,7 +9,6 @@ package org.mozilla.gecko.gfx;
 import android.content.Context;
 import android.graphics.Bitmap;
 import android.graphics.PixelFormat;
-import android.opengl.GLSurfaceView;
 import android.util.Log;
 import android.view.KeyEvent;
 import android.view.MotionEvent;
@@ -227,7 +193,7 @@ public class LayerView extends SurfaceView implements SurfaceHolder.Callback {
     }
 
 
-    public GLSurfaceView.Renderer getRenderer() {
+    public LayerRenderer getRenderer() {
         return mRenderer;
     }
 
@@ -235,7 +201,7 @@ public class LayerView extends SurfaceView implements SurfaceHolder.Callback {
         mListener = listener;
     }
 
-    public synchronized GLController getGLController() {
+    public GLController getGLController() {
         return mGLController;
     }
 
@@ -288,7 +254,7 @@ public class LayerView extends SurfaceView implements SurfaceHolder.Callback {
     public interface Listener {
         void renderRequested();
         void compositionPauseRequested();
-        void compositionResumeRequested();
+        void compositionResumeRequested(int width, int height);
         void surfaceChanged(int width, int height);
     }
 

android/experimental/LOAndroid3/src/java/org/mozilla/gecko/gfx/TouchEventHandler.java

@@ -10,8 +10,8 @@ import android.os.SystemClock;
 import android.view.GestureDetector;
 import android.view.MotionEvent;
 import android.view.View.OnTouchListener;
-import android.view.ViewConfiguration;
 
+import org.mozilla.gecko.ui.PanZoomController;
 import org.mozilla.gecko.ui.SimpleScaleGestureDetector;
 
 import java.util.LinkedList;
@@ -41,18 +41,24 @@ import java.util.Queue;
  * at some point after the first or second event in the block is processed in Gecko.
  * This code assumes we get EXACTLY ONE default-prevented notification for each block
  * of events.
+ *
+ * Note that even if all events are default-prevented, we still send specific types
+ * of notifications to the pan/zoom controller. The notifications are needed
+ * to respond to user actions a timely manner regardless of default-prevention,
+ * and fix issues like bug 749384.
  */
 public final class TouchEventHandler {
     private static final String LOGTAG = "GeckoTouchEventHandler";
 
     // The time limit for listeners to respond with preventDefault on touchevents
     // before we begin panning the page
-    private final int EVENT_LISTENER_TIMEOUT = ViewConfiguration.getLongPressTimeout();
+    private final int EVENT_LISTENER_TIMEOUT = 200;
 
     private final LayerView mView;
-    private final LayerController mController;
     private final GestureDetector mGestureDetector;
     private final SimpleScaleGestureDetector mScaleGestureDetector;
+    private final PanZoomController mPanZoomController;
+    private final GestureDetector.OnDoubleTapListener mDoubleTapListener;
 
     // the queue of events that we are holding on to while waiting for a preventDefault
     // notification
@@ -119,15 +125,16 @@ public final class TouchEventHandler {
 
     TouchEventHandler(Context context, LayerView view, LayerController controller) {
         mView = view;
-        mController = controller;
 
         mEventQueue = new LinkedList<MotionEvent>();
         mGestureDetector = new GestureDetector(context, controller.getGestureListener());
         mScaleGestureDetector = new SimpleScaleGestureDetector(controller.getScaleGestureListener());
+        mPanZoomController = controller.getPanZoomController();
         mListenerTimeoutProcessor = new ListenerTimeoutProcessor();
         mDispatchEvents = true;
 
-        mGestureDetector.setOnDoubleTapListener(controller.getDoubleTapListener());
+        mDoubleTapListener = controller.getDoubleTapListener();
+        setDoubleTapEnabled(true);
     }
 
     /* This function MUST be called on the UI thread */
@@ -142,7 +149,18 @@ public final class TouchEventHandler {
         if (isDownEvent(event)) {
             // this is the start of a new block of events! whee!
             mHoldInQueue = mWaitForTouchListeners;
+
+            // Set mDispatchEvents to true so that we are guaranteed to either queue these
+            // events or dispatch them. The only time we should not do either is once we've
+            // heard back from content to preventDefault this block.
+            mDispatchEvents = true;
             if (mHoldInQueue) {
+                // if the new block we are starting is the current block (i.e. there are no
+                // other blocks waiting in the queue, then we should let the pan/zoom controller
+                // know we are waiting for the touch listeners to run
+                if (mEventQueue.isEmpty()) {
+                    mPanZoomController.waitingForTouchListeners(event);
+                }
                 // if we're holding the events in the queue, set the timeout so that
                 // we dispatch these events if we don't get a default-prevented notification
                 mView.postDelayed(mListenerTimeoutProcessor, EVENT_LISTENER_TIMEOUT);
@@ -164,6 +182,8 @@ public final class TouchEventHandler {
             mEventQueue.add(MotionEvent.obtain(event));
         } else if (mDispatchEvents) {
             dispatchEvent(event);
+        } else if (touchFinished(event)) {
+            mPanZoomController.preventedTouchFinished();
         }
 
         // notify gecko of the event
@@ -192,6 +212,11 @@ public final class TouchEventHandler {
         mProcessingBalance--;
     }
 
+    /* This function MUST be called on the UI thread. */
+    public void setDoubleTapEnabled(boolean aValue) {
+        mGestureDetector.setOnDoubleTapListener(aValue ? mDoubleTapListener : null);
+    }
+
     /* This function MUST be called on the UI thread. */
     public void setWaitForTouchListeners(boolean aValue) {
         mWaitForTouchListeners = aValue;
@@ -207,18 +232,32 @@ public final class TouchEventHandler {
         return (action == MotionEvent.ACTION_DOWN || action == MotionEvent.ACTION_POINTER_DOWN);
     }
 
+    private boolean touchFinished(MotionEvent event) {
+        int action = (event.getAction() & MotionEvent.ACTION_MASK);
+        return (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_CANCEL);
+    }
+
     /**
      * Dispatch the event to the gesture detectors and the pan/zoom controller.
      */
     private void dispatchEvent(MotionEvent event) {
         if (mGestureDetector.onTouchEvent(event)) {
+            // An up/cancel event should get passed to both detectors, in
+            // case it comes from a pointer the scale detector is tracking.
+            switch (event.getAction() & MotionEvent.ACTION_MASK) {
+                case MotionEvent.ACTION_POINTER_UP:
+                case MotionEvent.ACTION_UP:
+                case MotionEvent.ACTION_CANCEL:
+                    break;
+                default:
                     return;
             }
+        }
         mScaleGestureDetector.onTouchEvent(event);
         if (mScaleGestureDetector.isInProgress()) {
             return;
         }
-        mController.getPanZoomController().onTouchEvent(event);
+        mPanZoomController.onTouchEvent(event);
     }
 
     /**
@@ -244,6 +283,8 @@ public final class TouchEventHandler {
             // default-prevented.
             if (allowDefaultAction) {
                 dispatchEvent(event);
+            } else if (touchFinished(event)) {
+                mPanZoomController.preventedTouchFinished();
             }
             event = mEventQueue.peek();
             if (event == null) {
@@ -259,6 +300,7 @@ public final class TouchEventHandler {
             if (isDownEvent(event)) {
                 // we have finished processing the block we were interested in.
                 // now we wait for the next call to processEventBlock
+                mPanZoomController.waitingForTouchListeners(event);
                 break;
             }
             // pop the event we peeked above, as it is still part of the block and

android/experimental/LOAndroid3/src/java/org/mozilla/gecko/ui/PanZoomController.java

 /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
- * ***** BEGIN LICENSE BLOCK *****
- * Version: MPL 1.1/GPL 2.0/LGPL 2.1
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (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.mozilla.org/MPL/
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- *
- * The Original Code is Mozilla Android code.
- *
- * The Initial Developer of the Original Code is Mozilla Foundation.
- * Portions created by the Initial Developer are Copyright (C) 2009-2012
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- *   Patrick Walton <pcwalton@mozilla.com>
- *   Kartikaya Gupta <kgupta@mozilla.com>
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either the GNU General Public License Version 2 or later (the "GPL"), or
- * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- * in which case the provisions of the GPL or the LGPL are applicable instead
- * of those above. If you wish to allow use of your version of this file only
- * under the terms of either the GPL or the LGPL, and not to allow others to
- * use your version of this file under the terms of the MPL, indicate your
- * decision by deleting the provisions above and replace them with the notice
- * and other provisions required by the GPL or the LGPL. If you do not delete
- * the provisions above, a recipient may use your version of this file under
- * the terms of any one of the MPL, the GPL or the LGPL.
- *
- * ***** END LICENSE BLOCK ***** */
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 package org.mozilla.gecko.ui;
 
@@ -52,6 +19,8 @@ import org.mozilla.gecko.gfx.LayerController;
 import org.mozilla.gecko.gfx.ViewportMetrics;
 import org.mozilla.gecko.util.FloatUtils;
 
+import java.util.Arrays;
+import java.util.StringTokenizer;
 import java.util.Timer;
 import java.util.TimerTask;
 
@@ -85,7 +54,7 @@ public class PanZoomController
     private static final float MAX_ZOOM = 4.0f;
 
     /* 16 precomputed frames of the _ease-out_ animation from the CSS Transitions specification. */
-    private static final float[] EASE_OUT_ANIMATION_FRAMES = {
+    private static float[] ZOOM_ANIMATION_FRAMES = new float[] {
         0.00000f,   /* 0 */
         0.10211f,   /* 1 */
         0.19864f,   /* 2 */
@@ -115,7 +84,11 @@ public class PanZoomController
         PANNING_HOLD_LOCKED, /* like PANNING_HOLD, but axis lock still in effect */
         PINCHING,       /* nth touch-start, where n > 1. this mode allows pan and zoom */
         ANIMATED_ZOOM,  /* animated zoom to a new rect */
-        BOUNCE          /* in a bounce animation */
+        BOUNCE,         /* in a bounce animation */
+
+        WAITING_LISTENERS, /* a state halfway between NOTHING and TOUCHING - the user has
+                        put a finger down, but we don't yet know if a touch listener has
+                        prevented the default actions yet. we still need to abort animations. */
     }
 
     private final LayerController mController;
@@ -156,6 +129,23 @@ public class PanZoomController
         }
     }
 
+    private void setZoomAnimationFrames(String frames) {
+        try {
+            if (frames.length() > 0) {
+                StringTokenizer st = new StringTokenizer(frames, ",");
+                float[] values = new float[st.countTokens()];
+                for (int i = 0; i < values.length; i++) {
+                    values[i] = Float.parseFloat(st.nextToken());
+                }
+                ZOOM_ANIMATION_FRAMES = values;
+            }
+        } catch (NumberFormatException e) {
+            Log.e(LOGTAG, "Error setting zoom animation frames", e);
+        } finally {
+            Log.i(LOGTAG, "Zoom animation frames: " + Arrays.toString(ZOOM_ANIMATION_FRAMES));
+        }
+    }
+
     public boolean onTouchEvent(MotionEvent event) {
         switch (event.getAction() & MotionEvent.ACTION_MASK) {
         case MotionEvent.ACTION_DOWN:   return onTouchStart(event);
@@ -195,6 +185,30 @@ public class PanZoomController
         }
     }
 
+    /** This function must be called on the UI thread. */
+    public void waitingForTouchListeners(MotionEvent event) {
+        checkMainThread();
+        if ((event.getAction() & MotionEvent.ACTION_MASK) == MotionEvent.ACTION_DOWN) {
+            // this is the first touch point going down, so we enter the pending state
+            mSubscroller.cancel();
+            // seting the state will kill any animations in progress, possibly leaving
+            // the page in overscroll
+            mState = PanZoomState.WAITING_LISTENERS;
+        }
+    }
+
+    /** This function must be called on the UI thread. */
+    public void preventedTouchFinished() {
+        checkMainThread();
+        if (mState == PanZoomState.WAITING_LISTENERS) {
+            // if we enter here, we just finished a block of events whose default actions
+            // were prevented by touch listeners. Now there are no touch points left, so
+            // we need to reset our state and re-bounce because we might be in overscroll
+            mState = PanZoomState.NOTHING;
+            bounce();
+        }
+    }
+
     /** This must be called on the UI thread. */
     public void pageSizeUpdated() {
         if (mState == PanZoomState.NOTHING) {
@@ -222,10 +236,16 @@ public class PanZoomController
 
         switch (mState) {
         case ANIMATED_ZOOM:
-            return false;
+            // We just interrupted a double-tap animation, so force a redraw in
+            // case this touchstart is just a tap that doesn't end up triggering
+            // a redraw
+            mController.setForceRedraw();
+            mController.notifyLayerClientOfGeometryChange();
+            // fall through
         case FLING:
         case BOUNCE:
         case NOTHING:
+        case WAITING_LISTENERS:
             startTouch(event.getX(0), event.getY(0), event.getEventTime());
             return false;
         case TOUCHING:
@@ -244,11 +264,16 @@ public class PanZoomController
     private boolean onTouchMove(MotionEvent event) {
 
         switch (mState) {
-        case NOTHING:
         case FLING:
         case BOUNCE:
+        case WAITING_LISTENERS:
             // should never happen
             Log.e(LOGTAG, "Received impossible touch move while in " + mState);
+            // fall through
+        case ANIMATED_ZOOM:
+        case NOTHING:
+            // may happen if user double-taps and drags without lifting after the
+            // second tap. ignore the move if this happens.
             return false;
 
         case TOUCHING:
@@ -274,7 +299,6 @@ public class PanZoomController
             track(event);
             return true;
 
-        case ANIMATED_ZOOM:
         case PINCHING:
             // scale gesture listener will handle this
             return false;
@@ -286,12 +310,18 @@ public class PanZoomController
     private boolean onTouchEnd(MotionEvent event) {
 
         switch (mState) {
-        case NOTHING:
         case FLING:
         case BOUNCE:
+        case WAITING_LISTENERS:
             // should never happen
             Log.e(LOGTAG, "Received impossible touch end while in " + mState);
+            // fall through
+        case ANIMATED_ZOOM:
+        case NOTHING:
+            // may happen if user double-taps and drags without lifting after the
+            // second tap. ignore if this happens.
             return false;
+
         case TOUCHING:
             mState = PanZoomState.NOTHING;
             // the switch into TOUCHING might have happened while the page was
@@ -299,6 +329,7 @@ public class PanZoomController
             // was the case
             bounce();
             return false;
+
         case PANNING:
         case PANNING_LOCKED:
         case PANNING_HOLD:
@@ -306,19 +337,28 @@ public class PanZoomController
             mState = PanZoomState.FLING;
             fling();
             return true;
+
         case PINCHING:
             mState = PanZoomState.NOTHING;
             return true;
-        case ANIMATED_ZOOM:
-            return false;
         }
         Log.e(LOGTAG, "Unhandled case " + mState + " in onTouchEnd");
         return false;
     }
 
     private boolean onTouchCancel(MotionEvent event) {
-        mState = PanZoomState.NOTHING;
+        if (mState == PanZoomState.WAITING_LISTENERS) {
+            // we might get a cancel event from the TouchEventHandler while in the
+            // WAITING_LISTENERS state if the touch listeners prevent-default the
+            // block of events. at this point being in WAITING_LISTENERS is equivalent
+            // to being in NOTHING with the exception of possibly being in overscroll.
+            // so here we don't want to do anything right now; the overscroll will be
+            // corrected in preventedTouchFinished().
+            return false;
+        }
+
         cancelTouch();
+        mState = PanZoomState.NOTHING;
         // ensure we snap back if we're overscrolled
         bounce();
         return false;
@@ -423,16 +463,17 @@ public class PanZoomController
             return;
         }
 
-        mState = PanZoomState.BOUNCE;
-        // set the animation target *after* setting state BOUNCE, so that
-        // the getRedrawHint() is returning false and we don't clobber the display
-        // port we set as a result of this animation target call.
+        // At this point we have already set mState to BOUNCE or ANIMATED_ZOOM, so
+        // getRedrawHint() is returning false. This means we can safely call
+        // setAnimationTarget to set the new final display port and not have it get
+        // clobbered by display ports from intermediate animation frames.
         mController.setAnimationTarget(metrics);
         startAnimationTimer(new BounceRunnable(bounceStartMetrics, metrics));
     }
 
     /* Performs a bounce-back animation to the nearest valid viewport metrics. */
     private void bounce() {
+        mState = PanZoomState.BOUNCE;
         bounce(getValidViewportMetrics());
     }
 
@@ -477,14 +518,14 @@ public class PanZoomController
         return getVelocity() < STOPPED_THRESHOLD;
     }
 
-    PointF getDisplacement() {
+    PointF resetDisplacement() {
         return new PointF(mX.resetDisplacement(), mY.resetDisplacement());
     }
 
     private void updatePosition() {
         mX.displace();
         mY.displace();
-        PointF displacement = getDisplacement();
+        PointF displacement = resetDisplacement();
         if (FloatUtils.fuzzyEquals(displacement.x, 0.0f) && FloatUtils.fuzzyEquals(displacement.y, 0.0f)) {
             return;
         }
@@ -542,13 +583,13 @@ public class PanZoomController
              * animation by setting the state to PanZoomState.NOTHING. Handle this case and bail
              * out.
              */
-            if (mState != PanZoomState.BOUNCE) {
+            if (!(mState == PanZoomState.BOUNCE || mState == PanZoomState.ANIMATED_ZOOM)) {
                 finishAnimation();
                 return;
             }
 
             /* Perform the next frame of the bounce-back animation. */
-            if (mBounceFrame < EASE_OUT_ANIMATION_FRAMES.length) {
+            if (mBounceFrame < ZOOM_ANIMATION_FRAMES.length) {
                 advanceBounce();
                 return;
             }
@@ -562,7 +603,7 @@ public class PanZoomController
         /* Performs one frame of a bounce animation. */
         private void advanceBounce() {
             synchronized (mController) {
-                float t = EASE_OUT_ANIMATION_FRAMES[mBounceFrame];
+                float t = ZOOM_ANIMATION_FRAMES[mBounceFrame];
                 ViewportMetrics newMetrics = mBounceStartMetrics.interpolate(mBounceEndMetrics, t);
                 mController.setViewportMetrics(newMetrics);
                 mController.notifyLayerClientOfGeometryChange();
@@ -655,19 +696,37 @@ public class PanZoomController
 
         float focusX = viewport.width() / 2.0f;
         float focusY = viewport.height() / 2.0f;
+
         float minZoomFactor = 0.0f;
-        if (viewport.width() > pageSize.width && pageSize.width > 0) {
+        float maxZoomFactor = MAX_ZOOM;
+
+        if (mController.getMinZoom() > 0)
+            minZoomFactor = mController.getMinZoom();
+        if (mController.getMaxZoom() > 0)
+            maxZoomFactor = mController.getMaxZoom();
+
+        if (!mController.getAllowZoom()) {
+            // If allowZoom is false, clamp to the default zoom level.
+            maxZoomFactor = minZoomFactor = mController.getDefaultZoom();
+        }
+
+        // Ensure minZoomFactor keeps the page at least as big as the viewport.
+        if (pageSize.width > 0) {
             float scaleFactor = viewport.width() / pageSize.width;
             minZoomFactor = Math.max(minZoomFactor, zoomFactor * scaleFactor);
+            if (viewport.width() > pageSize.width)
                 focusX = 0.0f;
         }
-        if (viewport.height() > pageSize.height && pageSize.height > 0) {
+        if (pageSize.height > 0) {
             float scaleFactor = viewport.height() / pageSize.height;
             minZoomFactor = Math.max(minZoomFactor, zoomFactor * scaleFactor);
+            if (viewport.height() > pageSize.height)
                 focusY = 0.0f;
         }
 
-        if (!FloatUtils.fuzzyEquals(minZoomFactor, 0.0f)) {
+        maxZoomFactor = Math.max(maxZoomFactor, minZoomFactor);
+
+        if (zoomFactor < minZoomFactor) {
             // if one (or both) of the page dimensions is smaller than the viewport,
             // zoom using the top/left as the focus on that axis. this prevents the
             // scenario where, if both dimensions are smaller than the viewport, but
@@ -675,9 +734,9 @@ public class PanZoomController
             // after applying the scale
             PointF center = new PointF(focusX, focusY);
             viewportMetrics.scaleTo(minZoomFactor, center);
-        } else if (zoomFactor > MAX_ZOOM) {
+        } else if (zoomFactor > maxZoomFactor) {
             PointF center = new PointF(viewport.width() / 2.0f, viewport.height() / 2.0f);
-            viewportMetrics.scaleTo(MAX_ZOOM, center);
+            viewportMetrics.scaleTo(maxZoomFactor, center);
         }
 
         /* Now we pan to the right origin. */
@@ -717,9 +776,11 @@ public class PanZoomController
         if (mState == PanZoomState.ANIMATED_ZOOM)
             return false;
 
+        if (!mController.getAllowZoom())
+            return false;
+
         mState = PanZoomState.PINCHING;
         mLastZoomFocus = new PointF(detector.getFocusX(), detector.getFocusY());
-
         cancelTouch();
 
         return true;
@@ -729,7 +790,8 @@ public class PanZoomController
     public boolean onScale(SimpleScaleGestureDetector detector) {
         Log.d(LOGTAG, "onScale in state " + mState);
 
-        if (mState == PanZoomState.ANIMATED_ZOOM)
+
+        if (mState != PanZoomState.PINCHING)
             return false;
 
         float prevSpan = detector.getPreviousSpan();
@@ -752,13 +814,31 @@ public class PanZoomController
 
         synchronized (mController) {
             float newZoomFactor = mController.getZoomFactor() * spanRatio;
-            if (newZoomFactor >= MAX_ZOOM) {
-                // apply resistance when zooming past MAX_ZOOM,
-                // such that it asymptotically reaches MAX_ZOOM + 1.0
+            float minZoomFactor = 0.0f;
+            float maxZoomFactor = MAX_ZOOM;
+
+            if (mController.getMinZoom() > 0)
+                minZoomFactor = mController.getMinZoom();
+            if (mController.getMaxZoom() > 0)
+                maxZoomFactor = mController.getMaxZoom();
+
+            if (newZoomFactor < minZoomFactor) {
+                // apply resistance when zooming past minZoomFactor,
+                // such that it asymptotically reaches minZoomFactor / 2.0
                 // but never exceeds that
-                float excessZoom = newZoomFactor - MAX_ZOOM;
+                final float rate = 0.5f; // controls how quickly we approach the limit
+                float excessZoom = minZoomFactor - newZoomFactor;
+                excessZoom = 1.0f - (float)Math.exp(-excessZoom * rate);
+                newZoomFactor = minZoomFactor * (1.0f - excessZoom / 2.0f);
+            }
+
+            if (newZoomFactor > maxZoomFactor) {
+                // apply resistance when zooming past maxZoomFactor,
+                // such that it asymptotically reaches maxZoomFactor + 1.0
+                // but never exceeds that
+                float excessZoom = newZoomFactor - maxZoomFactor;
                 excessZoom = 1.0f - (float)Math.exp(-excessZoom);
-                newZoomFactor = MAX_ZOOM + excessZoom;
+                newZoomFactor = maxZoomFactor + excessZoom;
             }
 
             mController.scrollBy(new PointF(mLastZoomFocus.x - detector.getFocusX(),
@@ -807,23 +887,37 @@ public class PanZoomController
     }
 
     @Override
-    public boolean onDown(MotionEvent motionEvent) {
+    public boolean onSingleTapUp(MotionEvent motionEvent) {
+        // When zooming is enabled, wait to see if there's a double-tap.
+        if (mController.getAllowZoom())
             return false;
+        return true;
     }
 
     @Override
     public boolean onSingleTapConfirmed(MotionEvent motionEvent) {
+        // When zooming is disabled, we handle this in onSingleTapUp.
+        if (!mController.getAllowZoom())
+            return false;
         return true;
     }
 
     @Override
     public boolean onDoubleTap(MotionEvent motionEvent) {
+        if (!mController.getAllowZoom())
+            return false;
         return true;
     }
 
-    public void cancelTouch() {
+    private void cancelTouch() {
     }
 
+    /**
+     * Zoom to a specified rect IN CSS PIXELS.
+     *
+     * While we usually use device pixels, @zoomToRect must be specified in CSS
+     * pixels.
+     */
     private boolean animatedZoomTo(RectF zoomToRect) {
         mState = PanZoomState.ANIMATED_ZOOM;
         final float startZoom = mController.getZoomFactor();
@@ -849,10 +943,11 @@ public class PanZoomController
             zoomToRect.right = zoomToRect.left + newWidth;
         }
 
-        float finalZoom = viewport.width() * startZoom / zoomToRect.width();
+        float finalZoom = viewport.width() / zoomToRect.width();
 
         ViewportMetrics finalMetrics = new ViewportMetrics(mController.getViewportMetrics());
-        finalMetrics.setOrigin(new PointF(zoomToRect.left, zoomToRect.top));
+        finalMetrics.setOrigin(new PointF(zoomToRect.left * finalMetrics.getZoomFactor(),
+                                          zoomToRect.top * finalMetrics.getZoomFactor()));
         finalMetrics.scaleTo(finalZoom, new PointF(0.0f, 0.0f));
 
         // 2. now run getValidViewportMetrics on it, so that the target viewport is