Merge java_staging/src into java/src.

chrome/android/java_staging/src/org/chromium/chrome/browser/compositor/layouts/phone/stack/StackScroller.java

Index: chrome/android/java_staging/src/org/chromium/chrome/browser/compositor/layouts/phone/stack/StackScroller.java
diff --git a/chrome/android/java_staging/src/org/chromium/chrome/browser/compositor/layouts/phone/stack/StackScroller.java b/chrome/android/java_staging/src/org/chromium/chrome/browser/compositor/layouts/phone/stack/StackScroller.java
deleted file mode 100644
index bfc43538137e3ab623bd2889650cb0bf8b9ca0fe..0000000000000000000000000000000000000000
--- a/chrome/android/java_staging/src/org/chromium/chrome/browser/compositor/layouts/phone/stack/StackScroller.java
+++ /dev/null
@@ -1,674 +0,0 @@
-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-package org.chromium.chrome.browser.compositor.layouts.phone.stack;
-
-import android.content.Context;
-import android.hardware.SensorManager;
-import android.util.Log;
-import android.view.ViewConfiguration;
-
-/**
- * This class is vastly copied from {@link android.widget.OverScroller} but decouples the time
- * from the app time so it can be specified manually.
- */
-public class StackScroller {
-    private int mMode;
-
-    private final SplineStackScroller mScrollerX;
-    private final SplineStackScroller mScrollerY;
-
-    private final boolean mFlywheel;
-
-    private static final int SCROLL_MODE = 0;
-    private static final int FLING_MODE = 1;
-
-    private static float sViscousFluidScale;
-    private static float sViscousFluidNormalize;
-
-    /**
-     * Creates an StackScroller with a viscous fluid scroll interpolator and flywheel.
-     * @param context
-     */
-    public StackScroller(Context context) {
-        mFlywheel = true;
-        mScrollerX = new SplineStackScroller(context);
-        mScrollerY = new SplineStackScroller(context);
-        initContants();
-    }
-
-    private static void initContants() {
-        // This controls the viscous fluid effect (how much of it)
-        sViscousFluidScale = 8.0f;
-        // must be set to 1.0 (used in viscousFluid())
-        sViscousFluidNormalize = 1.0f;
-        sViscousFluidNormalize = 1.0f / viscousFluid(1.0f);
-    }
-
-    /**
-     *
-     * Returns whether the scroller has finished scrolling.
-     *
-     * @return True if the scroller has finished scrolling, false otherwise.
-     */
-    public final boolean isFinished() {
-        return mScrollerX.mFinished && mScrollerY.mFinished;
-    }
-
-    /**
-     * Force the finished field to a particular value. Contrary to
-     * {@link #abortAnimation()}, forcing the animation to finished
-     * does NOT cause the scroller to move to the final x and y
-     * position.
-     *
-     * @param finished The new finished value.
-     */
-    public final void forceFinished(boolean finished) {
-        mScrollerX.mFinished = mScrollerY.mFinished = finished;
-    }
-
-    /**
-     * Returns the current X offset in the scroll.
-     *
-     * @return The new X offset as an absolute distance from the origin.
-     */
-    public final int getCurrX() {
-        return mScrollerX.mCurrentPosition;
-    }
-
-    /**
-     * Returns the current Y offset in the scroll.
-     *
-     * @return The new Y offset as an absolute distance from the origin.
-     */
-    public final int getCurrY() {
-        return mScrollerY.mCurrentPosition;
-    }
-
-    /**
-     * Returns where the scroll will end. Valid only for "fling" scrolls.
-     *
-     * @return The final X offset as an absolute distance from the origin.
-     */
-    public final int getFinalX() {
-        return mScrollerX.mFinal;
-    }
-
-    /**
-     * Returns where the scroll will end. Valid only for "fling" scrolls.
-     *
-     * @return The final Y offset as an absolute distance from the origin.
-     */
-    public final int getFinalY() {
-        return mScrollerY.mFinal;
-    }
-
-    /**
-     * Sets where the scroll will end.  Valid only for "fling" scrolls.
-     *
-     * @param x The final X offset as an absolute distance from the origin.
-     */
-    public final void setFinalX(int x) {
-        mScrollerX.setFinalPosition(x);
-    }
-
-    private static float viscousFluid(float x) {
-        x *= sViscousFluidScale;
-        if (x < 1.0f) {
-            x -= (1.0f - (float) Math.exp(-x));
-        } else {
-            float start = 0.36787944117f; // 1/e == exp(-1)
-            x = 1.0f - (float) Math.exp(1.0f - x);
-            x = start + x * (1.0f - start);
-        }
-        x *= sViscousFluidNormalize;
-        return x;
-    }
-
-    /**
-     * Call this when you want to know the new location. If it returns true, the
-     * animation is not yet finished.
-     */
-    public boolean computeScrollOffset(long time) {
-        if (isFinished()) {
-            return false;
-        }
-
-        switch (mMode) {
-            case SCROLL_MODE:
-                // Any scroller can be used for time, since they were started
-                // together in scroll mode. We use X here.
-                final long elapsedTime = time - mScrollerX.mStartTime;
-
-                final int duration = mScrollerX.mDuration;
-                if (elapsedTime < duration) {
-                    float q = (float) (elapsedTime) / duration;
-                    q = viscousFluid(q);
-                    mScrollerX.updateScroll(q);
-                    mScrollerY.updateScroll(q);
-                } else {
-                    abortAnimation();
-                }
-                break;
-
-            case FLING_MODE:
-                if (!mScrollerX.mFinished) {
-                    if (!mScrollerX.update(time)) {
-                        if (!mScrollerX.continueWhenFinished(time)) {
-                            mScrollerX.finish();
-                        }
-                    }
-                }
-
-                if (!mScrollerY.mFinished) {
-                    if (!mScrollerY.update(time)) {
-                        if (!mScrollerY.continueWhenFinished(time)) {
-                            mScrollerY.finish();
-                        }
-                    }
-                }
-
-                break;
-
-            default:
-                break;
-        }
-
-        return true;
-    }
-
-    /**
-     * Start scrolling by providing a starting point and the distance to travel.
-     *
-     * @param startX Starting horizontal scroll offset in pixels. Positive
-     *        numbers will scroll the content to the left.
-     * @param startY Starting vertical scroll offset in pixels. Positive numbers
-     *        will scroll the content up.
-     * @param dx Horizontal distance to travel. Positive numbers will scroll the
-     *        content to the left.
-     * @param dy Vertical distance to travel. Positive numbers will scroll the
-     *        content up.
-     * @param duration Duration of the scroll in milliseconds.
-     */
-    public void startScroll(int startX, int startY, int dx, int dy, long startTime, int duration) {
-        mMode = SCROLL_MODE;
-        mScrollerX.startScroll(startX, dx, startTime, duration);
-        mScrollerY.startScroll(startY, dy, startTime, duration);
-    }
-
-    /**
-     * Call this when you want to 'spring back' into a valid coordinate range.
-     *
-     * @param startX Starting X coordinate
-     * @param startY Starting Y coordinate
-     * @param minX Minimum valid X value
-     * @param maxX Maximum valid X value
-     * @param minY Minimum valid Y value
-     * @param maxY Minimum valid Y value
-     * @return true if a springback was initiated, false if startX and startY were
-     *          already within the valid range.
-     */
-    public boolean springBack(
-            int startX, int startY, int minX, int maxX, int minY, int maxY, long time) {
-        mMode = FLING_MODE;
-
-        // Make sure both methods are called.
-        final boolean spingbackX = mScrollerX.springback(startX, minX, maxX, time);
-        final boolean spingbackY = mScrollerY.springback(startY, minY, maxY, time);
-        return spingbackX || spingbackY;
-    }
-
-    /**
-     * Start scrolling based on a fling gesture. The distance traveled will
-     * depend on the initial velocity of the fling.
-     *
-     * @param startX Starting point of the scroll (X)
-     * @param startY Starting point of the scroll (Y)
-     * @param velocityX Initial velocity of the fling (X) measured in pixels per second.
-     * @param velocityY Initial velocity of the fling (Y) measured in pixels per second
-     * @param minX Minimum X value. The scroller will not scroll past this point
-     *            unless overX > 0. If overfling is allowed, it will use minX as
-     *            a springback boundary.
-     * @param maxX Maximum X value. The scroller will not scroll past this point
-     *            unless overX > 0. If overfling is allowed, it will use maxX as
-     *            a springback boundary.
-     * @param minY Minimum Y value. The scroller will not scroll past this point
-     *            unless overY > 0. If overfling is allowed, it will use minY as
-     *            a springback boundary.
-     * @param maxY Maximum Y value. The scroller will not scroll past this point
-     *            unless overY > 0. If overfling is allowed, it will use maxY as
-     *            a springback boundary.
-     * @param overX Overfling range. If > 0, horizontal overfling in either
-     *            direction will be possible.
-     * @param overY Overfling range. If > 0, vertical overfling in either
-     *            direction will be possible.
-     */
-    public void fling(int startX, int startY, int velocityX, int velocityY, int minX, int maxX,
-            int minY, int maxY, int overX, int overY, long time) {
-        // Continue a scroll or fling in progress
-        if (mFlywheel && !isFinished()) {
-            float oldVelocityX = mScrollerX.mCurrVelocity;
-            float oldVelocityY = mScrollerY.mCurrVelocity;
-            if (Math.signum(velocityX) == Math.signum(oldVelocityX)
-                    && Math.signum(velocityY) == Math.signum(oldVelocityY)) {
-                velocityX += oldVelocityX;
-                velocityY += oldVelocityY;
-            }
-        }
-
-        mMode = FLING_MODE;
-        mScrollerX.fling(startX, velocityX, minX, maxX, overX, time);
-        mScrollerY.fling(startY, velocityY, minY, maxY, overY, time);
-    }
-
-    /**
-     * Stops the animation. Contrary to {@link #forceFinished(boolean)},
-     * aborting the animating causes the scroller to move to the final x and y
-     * positions.
-     *
-     * @see #forceFinished(boolean)
-     */
-    public void abortAnimation() {
-        mScrollerX.finish();
-        mScrollerY.finish();
-    }
-
-    static class SplineStackScroller {
-        // Initial position
-        private int mStart;
-
-        // Current position
-        private int mCurrentPosition;
-
-        // Final position
-        private int mFinal;
-
-        // Initial velocity
-        private int mVelocity;
-
-        // Current velocity
-        private float mCurrVelocity;
-
-        // Constant current deceleration
-        private float mDeceleration;
-
-        // Animation starting time, in system milliseconds
-        private long mStartTime;
-
-        // Animation duration, in milliseconds
-        private int mDuration;
-
-        // Duration to complete spline component of animation
-        private int mSplineDuration;
-
-        // Distance to travel along spline animation
-        private int mSplineDistance;
-
-        // Whether the animation is currently in progress
-        private boolean mFinished;
-
-        // The allowed overshot distance before boundary is reached.
-        private int mOver;
-
-        // Fling friction
-        private final float mFlingFriction = ViewConfiguration.getScrollFriction();
-
-        // Current state of the animation.
-        private int mState = SPLINE;
-
-        // Constant gravity value, used in the deceleration phase.
-        private static final float GRAVITY = 2000.0f;
-
-        // A context-specific coefficient adjusted to physical values.
-        private final float mPhysicalCoeff;
-
-        private static final float DECELERATION_RATE = (float) (Math.log(0.78) / Math.log(0.9));
-        private static final float INFLEXION = 0.35f; // Tension lines cross at (INFLEXION, 1)
-        private static final float START_TENSION = 0.5f;
-        private static final float END_TENSION = 1.0f;
-        private static final float P1 = START_TENSION * INFLEXION;
-        private static final float P2 = 1.0f - END_TENSION * (1.0f - INFLEXION);
-
-        private static final int NB_SAMPLES = 100;
-        private static final float[] SPLINE_POSITION = new float[NB_SAMPLES + 1];
-        private static final float[] SPLINE_TIME = new float[NB_SAMPLES + 1];
-
-        private static final int SPLINE = 0;
-        private static final int CUBIC = 1;
-        private static final int BALLISTIC = 2;
-
-        static {
-            float xMin = 0.0f;
-            float yMin = 0.0f;
-            for (int i = 0; i < NB_SAMPLES; i++) {
-                final float alpha = (float) i / NB_SAMPLES;
-
-                float xMax = 1.0f;
-                float x, tx, coef;
-                while (true) {
-                    x = xMin + (xMax - xMin) / 2.0f;
-                    coef = 3.0f * x * (1.0f - x);
-                    tx = coef * ((1.0f - x) * P1 + x * P2) + x * x * x;
-                    if (Math.abs(tx - alpha) < 1E-5) break;
-                    if (tx > alpha) {
-                        xMax = x;
-                    } else {
-                        xMin = x;
-                    }
-                }
-                SPLINE_POSITION[i] = coef * ((1.0f - x) * START_TENSION + x) + x * x * x;
-
-                float yMax = 1.0f;
-                float y, dy;
-                while (true) {
-                    y = yMin + (yMax - yMin) / 2.0f;
-                    coef = 3.0f * y * (1.0f - y);
-                    dy = coef * ((1.0f - y) * START_TENSION + y) + y * y * y;
-                    if (Math.abs(dy - alpha) < 1E-5) break;
-                    if (dy > alpha) {
-                        yMax = y;
-                    } else {
-                        yMin = y;
-                    }
-                }
-                SPLINE_TIME[i] = coef * ((1.0f - y) * P1 + y * P2) + y * y * y;
-            }
-            SPLINE_POSITION[NB_SAMPLES] = SPLINE_TIME[NB_SAMPLES] = 1.0f;
-        }
-
-        SplineStackScroller(Context context) {
-            mFinished = true;
-            final float ppi = context.getResources().getDisplayMetrics().density * 160.0f;
-            mPhysicalCoeff = SensorManager.GRAVITY_EARTH // g (m/s^2)
-                    * 39.37f // inch/meter
-                    * ppi * 0.84f; // look and feel tuning
-        }
-
-        void updateScroll(float q) {
-            mCurrentPosition = mStart + Math.round(q * (mFinal - mStart));
-        }
-
-        /*
-         * Get a signed deceleration that will reduce the velocity.
-         */
-        private static float getDeceleration(int velocity) {
-            return velocity > 0 ? -GRAVITY : GRAVITY;
-        }
-
-        /*
-         * Modifies mDuration to the duration it takes to get from start to newFinal using the
-         * spline interpolation. The previous duration was needed to get to oldFinal.
-         */
-        private void adjustDuration(int start, int oldFinal, int newFinal) {
-            final int oldDistance = oldFinal - start;
-            final int newDistance = newFinal - start;
-            final float x = Math.abs((float) newDistance / oldDistance);
-            final int index = (int) (NB_SAMPLES * x);
-            if (index < NB_SAMPLES) {
-                final float xInf = (float) index / NB_SAMPLES;
-                final float xSup = (float) (index + 1) / NB_SAMPLES;
-                final float tInf = SPLINE_TIME[index];
-                final float tSup = SPLINE_TIME[index + 1];
-                final float timeCoef = tInf + (x - xInf) / (xSup - xInf) * (tSup - tInf);
-                mDuration *= timeCoef;
-            }
-        }
-
-        void startScroll(int start, int distance, long startTime, int duration) {
-            mFinished = false;
-
-            mStart = start;
-            mFinal = start + distance;
-
-            mStartTime = startTime;
-            mDuration = duration;
-
-            // Unused
-            mDeceleration = 0.0f;
-            mVelocity = 0;
-        }
-
-        void finish() {
-            mCurrentPosition = mFinal;
-            // Not reset since WebView relies on this value for fast fling.
-            // TODO: restore when WebView uses the fast fling implemented in this class.
-            // mCurrVelocity = 0.0f;
-            mFinished = true;
-        }
-
-        void setFinalPosition(int position) {
-            mFinal = position;
-            mFinished = false;
-        }
-
-        boolean springback(int start, int min, int max, long time) {
-            mFinished = true;
-
-            mStart = mFinal = start;
-            mVelocity = 0;
-
-            mStartTime = time;
-            mDuration = 0;
-
-            if (start < min) {
-                startSpringback(start, min, 0);
-            } else if (start > max) {
-                startSpringback(start, max, 0);
-            }
-
-            return !mFinished;
-        }
-
-        private void startSpringback(int start, int end, int velocity) {
-            // mStartTime has been set
-            mFinished = false;
-            mState = CUBIC;
-            mStart = start;
-            mFinal = end;
-            final int delta = start - end;
-            mDeceleration = getDeceleration(delta);
-            // TODO take velocity into account
-            mVelocity = -delta; // only sign is used
-            mOver = Math.abs(delta);
-            mDuration = (int) (1000.0 * Math.sqrt(-2.0 * delta / mDeceleration));
-        }
-
-        void fling(int start, int velocity, int min, int max, int over, long time) {
-            mOver = over;
-            mFinished = false;
-            mCurrVelocity = mVelocity = velocity;
-            mDuration = mSplineDuration = 0;
-            mStartTime = time;
-            mCurrentPosition = mStart = start;
-
-            if (start > max || start < min) {
-                startAfterEdge(start, min, max, velocity, time);
-                return;
-            }
-
-            mState = SPLINE;
-            double totalDistance = 0.0;
-
-            if (velocity != 0) {
-                mDuration = mSplineDuration = getSplineFlingDuration(velocity);
-                totalDistance = getSplineFlingDistance(velocity);
-            }
-
-            mSplineDistance = (int) (totalDistance * Math.signum(velocity));
-            mFinal = start + mSplineDistance;
-
-            // Clamp to a valid final position
-            if (mFinal < min) {
-                adjustDuration(mStart, mFinal, min);
-                mFinal = min;
-            }
-
-            if (mFinal > max) {
-                adjustDuration(mStart, mFinal, max);
-                mFinal = max;
-            }
-        }
-
-        private double getSplineDeceleration(int velocity) {
-            return Math.log(INFLEXION * Math.abs(velocity) / (mFlingFriction * mPhysicalCoeff));
-        }
-
-        private double getSplineFlingDistance(int velocity) {
-            final double l = getSplineDeceleration(velocity);
-            final double decelMinusOne = DECELERATION_RATE - 1.0;
-            return mFlingFriction * mPhysicalCoeff
-                    * Math.exp(DECELERATION_RATE / decelMinusOne * l);
-        }
-
-        /* Returns the duration, expressed in milliseconds */
-        private int getSplineFlingDuration(int velocity) {
-            final double l = getSplineDeceleration(velocity);
-            final double decelMinusOne = DECELERATION_RATE - 1.0;
-            return (int) (1000.0 * Math.exp(l / decelMinusOne));
-        }
-
-        private void fitOnBounceCurve(int start, int end, int velocity) {
-            // Simulate a bounce that started from edge
-            final float durationToApex = -velocity / mDeceleration;
-            final float distanceToApex = velocity * velocity / 2.0f / Math.abs(mDeceleration);
-            final float distanceToEdge = Math.abs(end - start);
-            final float totalDuration = (float) Math.sqrt(
-                    2.0 * (distanceToApex + distanceToEdge) / Math.abs(mDeceleration));
-            mStartTime -= (int) (1000.0f * (totalDuration - durationToApex));
-            mStart = end;
-            mVelocity = (int) (-mDeceleration * totalDuration);
-        }
-
-        private void startBounceAfterEdge(int start, int end, int velocity) {
-            mDeceleration = getDeceleration(velocity == 0 ? start - end : velocity);
-            fitOnBounceCurve(start, end, velocity);
-            onEdgeReached();
-        }
-
-        private void startAfterEdge(int start, int min, int max, int velocity, long time) {
-            if (start > min && start < max) {
-                Log.e("StackScroller", "startAfterEdge called from a valid position");
-                mFinished = true;
-                return;
-            }
-            final boolean positive = start > max;
-            final int edge = positive ? max : min;
-            final int overDistance = start - edge;
-            boolean keepIncreasing = overDistance * velocity >= 0;
-            if (keepIncreasing) {
-                // Will result in a bounce or a to_boundary depending on velocity.
-                startBounceAfterEdge(start, edge, velocity);
-            } else {
-                final double totalDistance = getSplineFlingDistance(velocity);
-                if (totalDistance > Math.abs(overDistance)) {
-                    fling(start, velocity, positive ? min : start, positive ? start : max, mOver,
-                            time);
-                } else {
-                    startSpringback(start, edge, velocity);
-                }
-            }
-        }
-
-        private void onEdgeReached() {
-            // mStart, mVelocity and mStartTime were adjusted to their values when edge was reached.
-            float distance = mVelocity * mVelocity / (2.0f * Math.abs(mDeceleration));
-            final float sign = Math.signum(mVelocity);
-
-            if (distance > mOver) {
-                // Default deceleration is not sufficient to slow us down before boundary
-                mDeceleration = -sign * mVelocity * mVelocity / (2.0f * mOver);
-                distance = mOver;
-            }
-
-            mOver = (int) distance;
-            mState = BALLISTIC;
-            mFinal = mStart + (int) (mVelocity > 0 ? distance : -distance);
-            mDuration = -(int) (1000.0f * mVelocity / mDeceleration);
-        }
-
-        boolean continueWhenFinished(long time) {
-            switch (mState) {
-                case SPLINE:
-                    // Duration from start to null velocity
-                    if (mDuration < mSplineDuration) {
-                        // If the animation was clamped, we reached the edge
-                        mStart = mFinal;
-                        // TODO Better compute speed when edge was reached
-                        mVelocity = (int) mCurrVelocity;
-                        mDeceleration = getDeceleration(mVelocity);
-                        mStartTime += mDuration;
-                        onEdgeReached();
-                    } else {
-                        // Normal stop, no need to continue
-                        return false;
-                    }
-                    break;
-                case BALLISTIC:
-                    mStartTime += mDuration;
-                    startSpringback(mFinal, mStart, 0);
-                    break;
-                case CUBIC:
-                    return false;
-            }
-
-            update(time);
-            return true;
-        }
-
-        /*
-         * Update the current position and velocity for current time. Returns
-         * true if update has been done and false if animation duration has been
-         * reached.
-         */
-        boolean update(long time) {
-            final long currentTime = time - mStartTime;
-
-            if (currentTime > mDuration) {
-                return false;
-            }
-
-            double distance = 0.0;
-            switch (mState) {
-                case SPLINE: {
-                    final float t = (float) currentTime / mSplineDuration;
-                    final int index = (int) (NB_SAMPLES * t);
-                    float distanceCoef = 1.f;
-                    float velocityCoef = 0.f;
-                    if (index < NB_SAMPLES) {
-                        final float tInf = (float) index / NB_SAMPLES;
-                        final float tSup = (float) (index + 1) / NB_SAMPLES;
-                        final float dInf = SPLINE_POSITION[index];
-                        final float dSup = SPLINE_POSITION[index + 1];
-                        velocityCoef = (dSup - dInf) / (tSup - tInf);
-                        distanceCoef = dInf + (t - tInf) * velocityCoef;
-                    }
-
-                    distance = distanceCoef * mSplineDistance;
-                    mCurrVelocity = velocityCoef * mSplineDistance / mSplineDuration * 1000.0f;
-                    break;
-                }
-
-                case BALLISTIC: {
-                    final float t = currentTime / 1000.0f;
-                    mCurrVelocity = mVelocity + mDeceleration * t;
-                    distance = mVelocity * t + mDeceleration * t * t / 2.0f;
-                    break;
-                }
-
-                case CUBIC: {
-                    final float t = (float) (currentTime) / mDuration;
-                    final float t2 = t * t;
-                    final float sign = Math.signum(mVelocity);
-                    distance = sign * mOver * (3.0f * t2 - 2.0f * t * t2);
-                    mCurrVelocity = sign * mOver * 6.0f * (-t + t2);
-                    break;
-                }
-            }
-
-            mCurrentPosition = mStart + (int) Math.round(distance);
-
-            return true;
-        }
-    }
-}