/* -*- 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 * * 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 ***** */ package org.mozilla.gecko.ui; import org.json.JSONObject; import org.json.JSONException; import org.mozilla.gecko.gfx.FloatSize; import org.mozilla.gecko.gfx.LayerController; import org.mozilla.gecko.gfx.PointUtils; import org.mozilla.gecko.gfx.ViewportMetrics; import org.mozilla.gecko.FloatUtils; import org.mozilla.gecko.GeckoApp; import org.mozilla.gecko.GeckoAppShell; import org.mozilla.gecko.GeckoEvent; import org.mozilla.gecko.GeckoEventListener; import android.graphics.PointF; import android.graphics.RectF; import android.util.Log; import android.view.GestureDetector; import android.view.MotionEvent; import android.view.ScaleGestureDetector; import java.lang.Math; import java.util.Date; import java.util.Timer; import java.util.TimerTask; /* * Handles the kinetic scrolling and zooming physics for a layer controller. * * Many ideas are from Joe Hewitt's Scrollability: * https://github.com/joehewitt/scrollability/ */ public class PanZoomController extends GestureDetector.SimpleOnGestureListener implements ScaleGestureDetector.OnScaleGestureListener, GeckoEventListener { private static final String LOGTAG = "GeckoPanZoomController"; private LayerController mController; // This fraction of velocity remains after every animation frame when the velocity is low. private static final float FRICTION_SLOW = 0.85f; // This fraction of velocity remains after every animation frame when the velocity is high. private static final float FRICTION_FAST = 0.97f; // Below this velocity (in pixels per frame), the friction starts increasing from FRICTION_FAST // to FRICTION_SLOW. private static final float VELOCITY_THRESHOLD = 10.0f; // Animation stops if the velocity is below this value when overscrolled or panning. private static final float STOPPED_THRESHOLD = 4.0f; // Animation stops is the velocity is below this threshold when flinging. private static final float FLING_STOPPED_THRESHOLD = 0.1f; // The percentage of the surface which can be overscrolled before it must snap back. private static final float SNAP_LIMIT = 0.75f; // The rate of deceleration when the surface has overscrolled. private static final float OVERSCROLL_DECEL_RATE = 0.04f; // The distance the user has to pan before we recognize it as such (e.g. to avoid // 1-pixel pans between the touch-down and touch-up of a click). In units of inches. private static final float PAN_THRESHOLD = 0.1f; // Angle from axis within which we stay axis-locked private static final double AXIS_LOCK_ANGLE = Math.PI / 6.0; // 30 degrees // The maximum velocity change factor between events, per ms, in %. // Direction changes are excluded. private static final float MAX_EVENT_ACCELERATION = 0.012f; // The minimum amount of space that must be present for an axis to be considered scrollable, // in pixels. private static final float MIN_SCROLLABLE_DISTANCE = 0.5f; // The maximum amount we allow you to zoom into a page 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 = { 0.00000f, /* 0 */ 0.10211f, /* 1 */ 0.19864f, /* 2 */ 0.29043f, /* 3 */ 0.37816f, /* 4 */ 0.46155f, /* 5 */ 0.54054f, /* 6 */ 0.61496f, /* 7 */ 0.68467f, /* 8 */ 0.74910f, /* 9 */ 0.80794f, /* 10 */ 0.86069f, /* 11 */ 0.90651f, /* 12 */ 0.94471f, /* 13 */ 0.97401f, /* 14 */ 0.99309f, /* 15 */ }; /* The timer that handles flings or bounces. */ private Timer mAnimationTimer; /* The runnable being scheduled by the animation timer. */ private AnimationRunnable mAnimationRunnable; /* Information about the X axis. */ private AxisX mX; /* Information about the Y axis. */ private AxisY mY; /* The zoom focus at the first zoom event (in page coordinates). */ private PointF mLastZoomFocus; /* The time the last motion event took place. */ private long mLastEventTime; private enum PanZoomState { NOTHING, /* no touch-start events received */ FLING, /* all touches removed, but we're still scrolling page */ TOUCHING, /* one touch-start event received */ PANNING_LOCKED, /* touch-start followed by move (i.e. panning with axis lock) */ PANNING, /* panning without axis lock */ PANNING_HOLD, /* in panning, but not moving. * similar to TOUCHING but after starting a pan */ 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 */ } private PanZoomState mState; private boolean mOverridePanning; private boolean mOverrideScrollAck; private boolean mOverrideScrollPending; public PanZoomController(LayerController controller) { mController = controller; mX = new AxisX(); mY = new AxisY(); mState = PanZoomState.NOTHING; GeckoAppShell.registerGeckoEventListener("Browser:ZoomToRect", this); GeckoAppShell.registerGeckoEventListener("Browser:ZoomToPageWidth", this); GeckoAppShell.registerGeckoEventListener("Panning:Override", this); GeckoAppShell.registerGeckoEventListener("Panning:CancelOverride", this); GeckoAppShell.registerGeckoEventListener("Gesture:ScrollAck", this); } protected void finalize() throws Throwable { GeckoAppShell.unregisterGeckoEventListener("Browser:ZoomToRect", this); GeckoAppShell.unregisterGeckoEventListener("Browser:ZoomToPageWidth", this); GeckoAppShell.unregisterGeckoEventListener("Panning:Override", this); GeckoAppShell.unregisterGeckoEventListener("Panning:CancelOverride", this); GeckoAppShell.unregisterGeckoEventListener("Gesture:ScrollAck", this); super.finalize(); } public void handleMessage(String event, JSONObject message) { Log.i(LOGTAG, "Got message: " + event); try { if ("Panning:Override".equals(event)) { mOverridePanning = true; mOverrideScrollAck = true; } else if ("Panning:CancelOverride".equals(event)) { mOverridePanning = false; } else if ("Gesture:ScrollAck".equals(event)) { mController.post(new Runnable() { public void run() { mOverrideScrollAck = true; if (mOverridePanning && mOverrideScrollPending) updatePosition(); } }); } else if (event.equals("Browser:ZoomToRect")) { if (mController != null) { float scale = mController.getZoomFactor(); float x = (float)message.getDouble("x"); float y = (float)message.getDouble("y"); final RectF zoomRect = new RectF(x, y, x + (float)message.getDouble("w"), y + (float)message.getDouble("h")); mController.post(new Runnable() { public void run() { animatedZoomTo(zoomRect); } }); } } else if (event.equals("Browser:ZoomToPageWidth")) { if (mController != null) { float scale = mController.getZoomFactor(); FloatSize pageSize = mController.getPageSize(); RectF viewableRect = mController.getViewport(); float y = viewableRect.top; // attempt to keep zoom keep focused on the center of the viewport float dh = viewableRect.height()*(1 - pageSize.width/viewableRect.width()); // increase in the height final RectF r = new RectF(0.0f, y + dh/2, pageSize.width, (y + pageSize.width * viewableRect.height()/viewableRect.width())); mController.post(new Runnable() { public void run() { animatedZoomTo(r); } }); } } } catch (Exception e) { Log.e(LOGTAG, "Exception handling message \"" + event + "\":", e); } } public boolean onTouchEvent(MotionEvent event) { switch (event.getAction() & event.ACTION_MASK) { case MotionEvent.ACTION_DOWN: return onTouchStart(event); case MotionEvent.ACTION_MOVE: return onTouchMove(event); case MotionEvent.ACTION_UP: return onTouchEnd(event); case MotionEvent.ACTION_CANCEL: return onTouchCancel(event); default: return false; } } /** This function must be called from the UI thread. */ @SuppressWarnings("fallthrough") public void abortAnimation() { // this happens when gecko changes the viewport on us or if the device is rotated. // if that's the case, abort any animation in progress and re-zoom so that the page // snaps to edges. for other cases (where the user's finger(s) are down) don't do // anything special. switch (mState) { case FLING: mX.velocity = mY.velocity = 0.0f; mState = PanZoomState.NOTHING; // fall through case ANIMATED_ZOOM: // the zoom that's in progress likely makes no sense any more (such as if // the screen orientation changed) so abort it and start a new one to // ensure the viewport doesn't contain out-of-bounds areas case NOTHING: // Don't do animations here; they're distracting and can cause flashes on page // transitions. mController.setViewportMetrics(getValidViewportMetrics()); mController.notifyLayerClientOfGeometryChange(); break; } } /* * Panning/scrolling */ private boolean onTouchStart(MotionEvent event) { Log.d(LOGTAG, "onTouchStart in state " + mState); // user is taking control of movement, so stop // any auto-movement we have going stopAnimationTimer(); mOverridePanning = false; switch (mState) { case ANIMATED_ZOOM: return false; case FLING: case NOTHING: mState = PanZoomState.TOUCHING; mX.velocity = mY.velocity = 0.0f; mX.locked = mY.locked = false; mX.lastTouchPos = mX.firstTouchPos = mX.touchPos = event.getX(0); mY.lastTouchPos = mY.firstTouchPos = mY.touchPos = event.getY(0); mLastEventTime = event.getEventTime(); return false; case TOUCHING: case PANNING: case PANNING_LOCKED: case PANNING_HOLD: case PANNING_HOLD_LOCKED: case PINCHING: mState = PanZoomState.PINCHING; return false; } Log.e(LOGTAG, "Unhandled case " + mState + " in onTouchStart"); return false; } @SuppressWarnings("fallthrough") private boolean onTouchMove(MotionEvent event) { Log.d(LOGTAG, "onTouchMove in state " + mState); switch (mState) { case NOTHING: case FLING: // should never happen Log.e(LOGTAG, "Received impossible touch move while in " + mState); return false; case TOUCHING: if (panDistance(event) < PAN_THRESHOLD * GeckoAppShell.getDpi()) return false; cancelTouch(); // fall through case PANNING_HOLD_LOCKED: GeckoApp.mAppContext.mAutoCompletePopup.hide(); mState = PanZoomState.PANNING_LOCKED; // fall through case PANNING_LOCKED: track(event); return true; case PANNING_HOLD: GeckoApp.mAppContext.mAutoCompletePopup.hide(); mState = PanZoomState.PANNING; // fall through case PANNING: track(event); return true; case ANIMATED_ZOOM: case PINCHING: // scale gesture listener will handle this return false; } Log.e(LOGTAG, "Unhandled case " + mState + " in onTouchMove"); return false; } private boolean onTouchEnd(MotionEvent event) { Log.d(LOGTAG, "onTouchEnd in " + mState); switch (mState) { case NOTHING: case FLING: // should never happen Log.e(LOGTAG, "Received impossible touch end while in " + mState); return false; case TOUCHING: mState = PanZoomState.NOTHING; // the switch into TOUCHING might have happened while the page was // snapping back after overscroll. we need to finish the snap if that // was the case bounce(); return false; case PANNING: case PANNING_LOCKED: case PANNING_HOLD: case PANNING_HOLD_LOCKED: mState = PanZoomState.FLING; fling(); return true; case PINCHING: int points = event.getPointerCount(); if (points == 1) { // last touch up mState = PanZoomState.NOTHING; } else if (points == 2) { int pointRemovedIndex = event.getActionIndex(); int pointRemainingIndex = 1 - pointRemovedIndex; // kind of a hack mState = PanZoomState.TOUCHING; mX.firstTouchPos = mX.touchPos = event.getX(pointRemainingIndex); mX.firstTouchPos = mY.touchPos = event.getY(pointRemainingIndex); } else { // still pinching, do nothing } return true; case ANIMATED_ZOOM: return false; } Log.e(LOGTAG, "Unhandled case " + mState + " in onTouchEnd"); return false; } private boolean onTouchCancel(MotionEvent event) { Log.d(LOGTAG, "onTouchCancel in " + mState); mState = PanZoomState.NOTHING; // ensure we snap back if we're overscrolled bounce(); return false; } private float panDistance(MotionEvent move) { float dx = mX.firstTouchPos - move.getX(0); float dy = mY.firstTouchPos - move.getY(0); return (float)Math.sqrt(dx * dx + dy * dy); } private float clampByFactor(float oldValue, float newValue, float factor) { float maxChange = Math.abs(oldValue * factor); return Math.min(oldValue + maxChange, Math.max(oldValue - maxChange, newValue)); } private void track(float x, float y, float lastX, float lastY, float timeDelta) { if (FloatUtils.fuzzyEquals(timeDelta, 0)) { // probably a duplicate event, ignore it. using a zero timeDelta will mess // up our velocity return; } if (mState == PanZoomState.PANNING_LOCKED) { // check to see if we should break the axis lock double angle = Math.atan2(y - mY.firstTouchPos, x - mX.firstTouchPos); // range [-pi, pi] angle = Math.abs(angle); // range [0, pi] if (angle < AXIS_LOCK_ANGLE || angle > (Math.PI - AXIS_LOCK_ANGLE)) { // lock to x-axis mX.locked = false; mY.locked = true; } else if (Math.abs(angle - (Math.PI / 2)) < AXIS_LOCK_ANGLE) { // lock to y-axis mX.locked = true; mY.locked = false; } else { // break axis lock but log the angle so we can fine-tune this when people complain mState = PanZoomState.PANNING; mX.locked = mY.locked = false; angle = Math.abs(angle - (Math.PI / 2)); // range [0, pi/2] Log.i(LOGTAG, "Breaking axis lock at " + (angle * 180.0 / Math.PI) + " degrees"); } } float newVelocityX = ((lastX - x) / timeDelta) * (1000.0f/60.0f); float newVelocityY = ((lastY - y) / timeDelta) * (1000.0f/60.0f); float maxChange = MAX_EVENT_ACCELERATION * timeDelta; // If there's a direction change, or current velocity is very low, // allow setting of the velocity outright. Otherwise, use the current // velocity and a maximum change factor to set the new velocity. if (Math.abs(mX.velocity) < 1.0f || (((mX.velocity > 0) != (newVelocityX > 0)) && !FloatUtils.fuzzyEquals(newVelocityX, 0.0f))) mX.velocity = newVelocityX; else mX.velocity = clampByFactor(mX.velocity, newVelocityX, maxChange); if (Math.abs(mY.velocity) < 1.0f || (((mY.velocity > 0) != (newVelocityY > 0)) && !FloatUtils.fuzzyEquals(newVelocityY, 0.0f))) mY.velocity = newVelocityY; else mY.velocity = clampByFactor(mY.velocity, newVelocityY, maxChange); } private void track(MotionEvent event) { mX.lastTouchPos = mX.touchPos; mY.lastTouchPos = mY.touchPos; for (int i = 0; i < event.getHistorySize(); i++) { float x = event.getHistoricalX(0, i); float y = event.getHistoricalY(0, i); long time = event.getHistoricalEventTime(i); float timeDelta = (float)(time - mLastEventTime); mLastEventTime = time; track(x, y, mX.touchPos, mY.touchPos, timeDelta); mX.touchPos = x; mY.touchPos = y; } float timeDelta = (float)(event.getEventTime() - mLastEventTime); mLastEventTime = event.getEventTime(); track(event.getX(0), event.getY(0), mX.touchPos, mY.touchPos, timeDelta); mX.touchPos = event.getX(0); mY.touchPos = event.getY(0); if (stopped()) { if (mState == PanZoomState.PANNING) { mState = PanZoomState.PANNING_HOLD; } else if (mState == PanZoomState.PANNING_LOCKED) { mState = PanZoomState.PANNING_HOLD_LOCKED; } else { // should never happen, but handle anyway for robustness Log.e(LOGTAG, "Impossible case " + mState + " when stopped in track"); mState = PanZoomState.PANNING_HOLD_LOCKED; } } mX.setFlingState(Axis.FlingStates.PANNING); mY.setFlingState(Axis.FlingStates.PANNING); mX.displace(mOverridePanning); mY.displace(mOverridePanning); updatePosition(); } private void fling() { if (mState != PanZoomState.FLING) mX.velocity = mY.velocity = 0.0f; mX.disableSnap = mY.disableSnap = mOverridePanning; mX.displace(mOverridePanning); mY.displace(mOverridePanning); updatePosition(); stopAnimationTimer(); boolean stopped = stopped(); mX.startFling(stopped); mY.startFling(stopped); startAnimationTimer(new FlingRunnable()); } /* Performs a bounce-back animation to the given viewport metrics. */ private void bounce(ViewportMetrics metrics) { stopAnimationTimer(); ViewportMetrics bounceStartMetrics = new ViewportMetrics(mController.getViewportMetrics()); if (bounceStartMetrics.fuzzyEquals(metrics)) { mState = PanZoomState.NOTHING; return; } mState = PanZoomState.FLING; mX.setFlingState(Axis.FlingStates.SNAPPING); mY.setFlingState(Axis.FlingStates.SNAPPING); Log.d(LOGTAG, "end bounce at " + metrics); startAnimationTimer(new BounceRunnable(bounceStartMetrics, metrics)); } /* Performs a bounce-back animation to the nearest valid viewport metrics. */ private void bounce() { bounce(getValidViewportMetrics()); } /* Starts the fling or bounce animation. */ private void startAnimationTimer(final AnimationRunnable runnable) { if (mAnimationTimer != null) { Log.e(LOGTAG, "Attempted to start a new fling without canceling the old one!"); stopAnimationTimer(); } mAnimationTimer = new Timer("Animation Timer"); mAnimationRunnable = runnable; mAnimationTimer.scheduleAtFixedRate(new TimerTask() { @Override public void run() { mController.post(runnable); } }, 0, 1000L/60L); } /* Stops the fling or bounce animation. */ private void stopAnimationTimer() { if (mAnimationTimer != null) { mAnimationTimer.cancel(); mAnimationTimer = null; } if (mAnimationRunnable != null) { mAnimationRunnable.terminate(); mAnimationRunnable = null; } } private boolean stopped() { float absVelocity = (float)Math.sqrt(mX.velocity * mX.velocity + mY.velocity * mY.velocity); return absVelocity < STOPPED_THRESHOLD; } private void updatePosition() { if (mOverridePanning) { if (!mOverrideScrollAck) { mOverrideScrollPending = true; return; } mOverrideScrollPending = false; JSONObject json = new JSONObject(); try { json.put("x", mX.displacement); json.put("y", mY.displacement); } catch (JSONException e) { Log.e(LOGTAG, "Error forming Gesture:Scroll message: " + e); } GeckoEvent e = new GeckoEvent("Gesture:Scroll", json.toString()); GeckoAppShell.sendEventToGecko(e); mOverrideScrollAck = false; } else { synchronized (mController) { mController.scrollBy(new PointF(mX.displacement, mY.displacement)); } } mX.displacement = mY.displacement = 0; } private abstract class AnimationRunnable implements Runnable { private boolean mAnimationTerminated; /* This should always run on the UI thread */ public final void run() { /* * Since the animation timer queues this runnable on the UI thread, it * is possible that even when the animation timer is cancelled, there * are multiple instances of this queued, so we need to have another * mechanism to abort. This is done by using the mAnimationTerminated flag. */ if (mAnimationTerminated) { return; } animateFrame(); } protected abstract void animateFrame(); /* This should always run on the UI thread */ protected final void terminate() { mAnimationTerminated = true; } } /* The callback that performs the bounce animation. */ private class BounceRunnable extends AnimationRunnable { /* The current frame of the bounce-back animation */ private int mBounceFrame; /* * The viewport metrics that represent the start and end of the bounce-back animation, * respectively. */ private ViewportMetrics mBounceStartMetrics; private ViewportMetrics mBounceEndMetrics; BounceRunnable(ViewportMetrics startMetrics, ViewportMetrics endMetrics) { mBounceStartMetrics = startMetrics; mBounceEndMetrics = endMetrics; } protected void animateFrame() { /* * The pan/zoom controller might have signaled to us that it wants to abort the * animation by setting the state to PanZoomState.NOTHING. Handle this case and bail * out. */ if (mState != PanZoomState.FLING) { finishAnimation(); return; } /* Perform the next frame of the bounce-back animation. */ if (mBounceFrame < EASE_OUT_ANIMATION_FRAMES.length) { advanceBounce(); return; } /* Finally, if there's nothing else to do, complete the animation and go to sleep. */ finishBounce(); finishAnimation(); mState = PanZoomState.NOTHING; } /* Performs one frame of a bounce animation. */ private void advanceBounce() { synchronized (mController) { float t = EASE_OUT_ANIMATION_FRAMES[mBounceFrame]; ViewportMetrics newMetrics = mBounceStartMetrics.interpolate(mBounceEndMetrics, t); mController.setViewportMetrics(newMetrics); mController.notifyLayerClientOfGeometryChange(); mBounceFrame++; } } /* Concludes a bounce animation and snaps the viewport into place. */ private void finishBounce() { synchronized (mController) { mController.setViewportMetrics(mBounceEndMetrics); mController.notifyLayerClientOfGeometryChange(); mBounceFrame = -1; } } } // The callback that performs the fling animation. private class FlingRunnable extends AnimationRunnable { protected void animateFrame() { /* * The pan/zoom controller might have signaled to us that it wants to abort the * animation by setting the state to PanZoomState.NOTHING. Handle this case and bail * out. */ if (mState != PanZoomState.FLING) { finishAnimation(); return; } /* Advance flings, if necessary. */ boolean flingingX = mX.getFlingState() == Axis.FlingStates.FLINGING; boolean flingingY = mY.getFlingState() == Axis.FlingStates.FLINGING; if (flingingX) mX.advanceFling(); if (flingingY) mY.advanceFling(); /* If we're still flinging in any direction, update the origin. */ if (flingingX || flingingY) { mX.displace(mOverridePanning); mY.displace(mOverridePanning); updatePosition(); /* * If we're still flinging with an appreciable velocity, stop here. The threshold is * higher in the case of overscroll, so we bounce back eagerly when overscrolling but * coast smoothly to a stop when not. */ float excess = PointUtils.distance(new PointF(mX.getExcess(), mY.getExcess())); PointF velocityVector = new PointF(mX.getRealVelocity(), mY.getRealVelocity()); float threshold = (excess >= 1.0f) ? STOPPED_THRESHOLD : FLING_STOPPED_THRESHOLD; if (PointUtils.distance(velocityVector) >= threshold) return; } /* * Perform a bounce-back animation if overscrolled, unless panning is being overridden * (which happens e.g. when the user is panning an iframe). */ boolean overscrolledX = mX.getOverscroll() != Axis.Overscroll.NONE; boolean overscrolledY = mY.getOverscroll() != Axis.Overscroll.NONE; if (!mOverridePanning && (overscrolledX || overscrolledY)) { bounce(); } else { finishAnimation(); mState = PanZoomState.NOTHING; } } } private void finishAnimation() { Log.d(LOGTAG, "Finishing animation at " + mController.getViewportMetrics()); stopAnimationTimer(); // Force a viewport synchronisation mController.setForceRedraw(); mController.notifyLayerClientOfGeometryChange(); } private float computeElasticity(float excess, float viewportLength) { return 1.0f - excess / (viewportLength * SNAP_LIMIT); } // Physics information for one axis (X or Y). private abstract static class Axis { public enum FlingStates { STOPPED, PANNING, FLINGING, WAITING_TO_SNAP, SNAPPING, } public enum Overscroll { NONE, MINUS, // Overscrolled in the negative direction PLUS, // Overscrolled in the positive direction BOTH, // Overscrolled in both directions (page is zoomed to smaller than screen) } public float firstTouchPos; /* Position of the first touch event on the current drag. */ public float touchPos; /* Position of the most recent touch event on the current drag. */ public float lastTouchPos; /* Position of the touch event before touchPos. */ public float velocity; /* Velocity in this direction. */ public boolean locked; /* Whether movement on this axis is locked. */ public boolean disableSnap; /* Whether overscroll snapping is disabled. */ private FlingStates mFlingState; /* The fling state we're in on this axis. */ public abstract float getOrigin(); protected abstract float getViewportLength(); protected abstract float getPageLength(); public float displacement; private int mSnapFrame; private float mSnapPos, mSnapEndPos; public Axis() { mSnapFrame = -1; } public FlingStates getFlingState() { return mFlingState; } public void setFlingState(FlingStates aFlingState) { mFlingState = aFlingState; } private float getViewportEnd() { return getOrigin() + getViewportLength(); } public Overscroll getOverscroll() { boolean minus = (getOrigin() < 0.0f); boolean plus = (getViewportEnd() > getPageLength()); if (minus && plus) return Overscroll.BOTH; else if (minus) return Overscroll.MINUS; else if (plus) return Overscroll.PLUS; else return Overscroll.NONE; } // Returns the amount that the page has been overscrolled. If the page hasn't been // overscrolled on this axis, returns 0. public float getExcess() { switch (getOverscroll()) { case MINUS: return -getOrigin(); case PLUS: return getViewportEnd() - getPageLength(); case BOTH: return getViewportEnd() - getPageLength() - getOrigin(); default: return 0.0f; } } /* * Returns true if the page is zoomed in to some degree along this axis such that scrolling * is possible. Otherwise, returns false. */ private boolean scrollable() { return getViewportLength() <= getPageLength() - MIN_SCROLLABLE_DISTANCE; } /* * Returns the resistance, as a multiplier, that should be taken into account when * tracking or pinching. */ public float getEdgeResistance() { float excess = getExcess(); return (excess > 0.0f) ? SNAP_LIMIT - excess / getViewportLength() : 1.0f; } /* Returns the velocity. If the axis is locked, returns 0. */ public float getRealVelocity() { return locked ? 0.0f : velocity; } public void startFling(boolean stopped) { if (!stopped) { setFlingState(FlingStates.FLINGING); return; } if (disableSnap || FloatUtils.fuzzyEquals(getExcess(), 0.0f)) setFlingState(FlingStates.STOPPED); else setFlingState(FlingStates.WAITING_TO_SNAP); } /* Advances a fling animation by one step. */ public void advanceFling() { // If we aren't overscrolled, just apply friction. float excess = getExcess(); if (disableSnap || FloatUtils.fuzzyEquals(excess, 0.0f)) { if (Math.abs(velocity) >= VELOCITY_THRESHOLD) { velocity *= FRICTION_FAST; } else { float t = velocity / VELOCITY_THRESHOLD; velocity *= FloatUtils.interpolate(FRICTION_SLOW, FRICTION_FAST, t); } if (Math.abs(velocity) < FLING_STOPPED_THRESHOLD) { velocity = 0.0f; setFlingState(FlingStates.STOPPED); } return; } // Otherwise, decrease the velocity linearly. float elasticity = 1.0f - excess / (getViewportLength() * SNAP_LIMIT); if (getOverscroll() == Overscroll.MINUS) velocity = Math.min((velocity + OVERSCROLL_DECEL_RATE) * elasticity, 0.0f); else // must be Overscroll.PLUS velocity = Math.max((velocity - OVERSCROLL_DECEL_RATE) * elasticity, 0.0f); if (Math.abs(velocity) < 0.3f) { velocity = 0.0f; setFlingState(FlingStates.WAITING_TO_SNAP); } } // Performs displacement of the viewport position according to the current velocity. public void displace(boolean panningOverridden) { if (!panningOverridden && (locked || !scrollable())) return; if (mFlingState == FlingStates.PANNING) displacement += (lastTouchPos - touchPos) * getEdgeResistance(); else displacement += velocity; } } /* Returns the nearest viewport metrics with no overscroll visible. */ private ViewportMetrics getValidViewportMetrics() { ViewportMetrics viewportMetrics = new ViewportMetrics(mController.getViewportMetrics()); Log.d(LOGTAG, "generating valid viewport using " + viewportMetrics); /* First, we adjust the zoom factor so that we can make no overscrolled area visible. */ float zoomFactor = viewportMetrics.getZoomFactor(); FloatSize pageSize = viewportMetrics.getPageSize(); RectF viewport = viewportMetrics.getViewport(); float minZoomFactor = 0.0f; if (viewport.width() > pageSize.width && pageSize.width > 0) { float scaleFactor = viewport.width() / pageSize.width; minZoomFactor = Math.max(minZoomFactor, zoomFactor * scaleFactor); } if (viewport.height() > pageSize.height && pageSize.height > 0) { float scaleFactor = viewport.height() / pageSize.height; minZoomFactor = Math.max(minZoomFactor, zoomFactor * scaleFactor); } if (!FloatUtils.fuzzyEquals(minZoomFactor, 0.0f)) { PointF center = new PointF(viewport.width() / 2.0f, viewport.height() / 2.0f); viewportMetrics.scaleTo(minZoomFactor, center); } else if (zoomFactor > MAX_ZOOM) { PointF center = new PointF(viewport.width() / 2.0f, viewport.height() / 2.0f); viewportMetrics.scaleTo(MAX_ZOOM, center); } /* Now we pan to the right origin. */ viewportMetrics.setViewport(viewportMetrics.getClampedViewport()); Log.d(LOGTAG, "generated valid viewport as " + viewportMetrics); return viewportMetrics; } private class AxisX extends Axis { @Override public float getOrigin() { return mController.getOrigin().x; } @Override protected float getViewportLength() { return mController.getViewportSize().width; } @Override protected float getPageLength() { return mController.getPageSize().width; } } private class AxisY extends Axis { @Override public float getOrigin() { return mController.getOrigin().y; } @Override protected float getViewportLength() { return mController.getViewportSize().height; } @Override protected float getPageLength() { return mController.getPageSize().height; } } /* * Zooming */ @Override public boolean onScale(ScaleGestureDetector detector) { Log.d(LOGTAG, "onScale in state " + mState); if (mState == PanZoomState.ANIMATED_ZOOM) return false; float prevSpan = detector.getPreviousSpan(); if (FloatUtils.fuzzyEquals(prevSpan, 0.0f)) { // let's eat this one to avoid setting the new zoom to infinity (bug 711453) return true; } float spanRatio = detector.getCurrentSpan() / prevSpan; /* * Apply edge resistance if we're zoomed out smaller than the page size by scaling the zoom * factor toward 1.0. */ float resistance = Math.min(mX.getEdgeResistance(), mY.getEdgeResistance()); if (spanRatio > 1.0f) spanRatio = 1.0f + (spanRatio - 1.0f) * resistance; else spanRatio = 1.0f - (1.0f - spanRatio) * resistance; 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 // but never exceeds that float excessZoom = newZoomFactor - MAX_ZOOM; excessZoom = 1.0f - (float)Math.exp(-excessZoom); newZoomFactor = MAX_ZOOM + excessZoom; } mController.scrollBy(new PointF(mLastZoomFocus.x - detector.getFocusX(), mLastZoomFocus.y - detector.getFocusY())); PointF focus = new PointF(detector.getFocusX(), detector.getFocusY()); mController.scaleWithFocus(newZoomFactor, focus); } mLastZoomFocus.set(detector.getFocusX(), detector.getFocusY()); return true; } @Override public boolean onScaleBegin(ScaleGestureDetector detector) { Log.d(LOGTAG, "onScaleBegin in " + mState); if (mState == PanZoomState.ANIMATED_ZOOM) return false; mState = PanZoomState.PINCHING; mLastZoomFocus = new PointF(detector.getFocusX(), detector.getFocusY()); GeckoApp.mAppContext.hidePluginViews(); GeckoApp.mAppContext.mAutoCompletePopup.hide(); cancelTouch(); return true; } @Override public void onScaleEnd(ScaleGestureDetector detector) { Log.d(LOGTAG, "onScaleEnd in " + mState); if (mState == PanZoomState.ANIMATED_ZOOM) return; mState = PanZoomState.PANNING_HOLD_LOCKED; mX.firstTouchPos = mX.lastTouchPos = mX.touchPos = detector.getFocusX(); mY.firstTouchPos = mY.lastTouchPos = mY.touchPos = detector.getFocusY(); // Force a viewport synchronisation mController.setForceRedraw(); mController.notifyLayerClientOfGeometryChange(); GeckoApp.mAppContext.showPluginViews(); mState = PanZoomState.TOUCHING; mX.velocity = mY.velocity = 0.0f; mX.locked = mY.locked = false; mLastEventTime = detector.getEventTime(); } @Override public void onLongPress(MotionEvent motionEvent) { String json; try { PointF point = new PointF(motionEvent.getX(), motionEvent.getY()); point = mController.convertViewPointToLayerPoint(point); if (point == null) { return; } json = PointUtils.toJSON(point).toString(); } catch(Exception ex) { Log.w(LOGTAG, "Error building return: " + ex); return; // json would be null } GeckoEvent e = new GeckoEvent("Gesture:LongPress", json); GeckoAppShell.sendEventToGecko(e); } public boolean getRedrawHint() { return (mState == PanZoomState.NOTHING || mState == PanZoomState.FLING); } @Override public boolean onDown(MotionEvent motionEvent) { String json; try { PointF point = new PointF(motionEvent.getX(), motionEvent.getY()); point = mController.convertViewPointToLayerPoint(point); json = PointUtils.toJSON(point).toString(); } catch(Exception ex) { throw new RuntimeException(ex); } GeckoEvent e = new GeckoEvent("Gesture:ShowPress", json); GeckoAppShell.sendEventToGecko(e); return false; } @Override public boolean onSingleTapConfirmed(MotionEvent motionEvent) { String json; try { PointF point = new PointF(motionEvent.getX(), motionEvent.getY()); point = mController.convertViewPointToLayerPoint(point); json = PointUtils.toJSON(point).toString(); } catch(Exception ex) { throw new RuntimeException(ex); } GeckoApp.mAppContext.mAutoCompletePopup.hide(); GeckoEvent e = new GeckoEvent("Gesture:SingleTap", json); GeckoAppShell.sendEventToGecko(e); return true; } private void cancelTouch() { GeckoEvent e = new GeckoEvent("Gesture:CancelTouch", ""); GeckoAppShell.sendEventToGecko(e); } @Override public boolean onDoubleTap(MotionEvent motionEvent) { String json; try { PointF point = new PointF(motionEvent.getX(), motionEvent.getY()); point = mController.convertViewPointToLayerPoint(point); json = PointUtils.toJSON(point).toString(); } catch(Exception ex) { throw new RuntimeException(ex); } GeckoEvent e = new GeckoEvent("Gesture:DoubleTap", json); GeckoAppShell.sendEventToGecko(e); return true; } private boolean animatedZoomTo(RectF zoomToRect) { GeckoApp.mAppContext.hidePluginViews(); GeckoApp.mAppContext.mAutoCompletePopup.hide(); mState = PanZoomState.ANIMATED_ZOOM; final float startZoom = mController.getZoomFactor(); final PointF startPoint = mController.getOrigin(); RectF viewport = mController.getViewport(); float newHeight = zoomToRect.width() * viewport.height() / viewport.width(); // if the requested rect would not fill the screen, shift it to be centered if (zoomToRect.height() < newHeight) { zoomToRect.top -= (newHeight - zoomToRect.height())/2; zoomToRect.bottom = zoomToRect.top + newHeight; } zoomToRect = mController.restrictToPageSize(zoomToRect); float finalZoom = viewport.width() * startZoom / zoomToRect.width(); ViewportMetrics finalMetrics = new ViewportMetrics(mController.getViewportMetrics()); finalMetrics.setOrigin(new PointF(zoomToRect.left, zoomToRect.top)); finalMetrics.scaleTo(finalZoom, new PointF(0.0f, 0.0f)); bounce(finalMetrics); return true; } }