auto import from //depot/cupcake/@135843
diff --git a/core/java/android/widget/Scroller.java b/core/java/android/widget/Scroller.java
new file mode 100644
index 0000000..febc956
--- /dev/null
+++ b/core/java/android/widget/Scroller.java
@@ -0,0 +1,388 @@
+/*
+ * Copyright (C) 2006 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.widget;
+
+import android.content.Context;
+import android.view.ViewConfiguration;
+import android.view.animation.AnimationUtils;
+import android.view.animation.Interpolator;
+
+
+/**
+ * This class encapsulates scrolling. The duration of the scroll
+ * can be passed in the constructor and specifies the maximum time that
+ * the scrolling animation should take. Past this time, the scrolling is
+ * automatically moved to its final stage and computeScrollOffset()
+ * will always return false to indicate that scrolling is over.
+ */
+public class Scroller {
+ private int mMode;
+
+ private int mStartX;
+ private int mStartY;
+ private int mFinalX;
+ private int mFinalY;
+
+ private int mMinX;
+ private int mMaxX;
+ private int mMinY;
+ private int mMaxY;
+
+ private int mCurrX;
+ private int mCurrY;
+ private long mStartTime;
+ private int mDuration;
+ private float mDurationReciprocal;
+ private float mDeltaX;
+ private float mDeltaY;
+ private float mViscousFluidScale;
+ private float mViscousFluidNormalize;
+ private boolean mFinished;
+ private Interpolator mInterpolator;
+
+ private float mCoeffX = 0.0f;
+ private float mCoeffY = 1.0f;
+ private float mVelocity;
+
+ private static final int DEFAULT_DURATION = 250;
+ private static final int SCROLL_MODE = 0;
+ private static final int FLING_MODE = 1;
+
+ private final float mDeceleration;
+
+ /**
+ * Create a Scroller with the default duration and interpolator.
+ */
+ public Scroller(Context context) {
+ this(context, null);
+ }
+
+ /**
+ * Create a Scroller with the specified interpolator. If the interpolator is
+ * null, the default (viscous) interpolator will be used.
+ */
+ public Scroller(Context context, Interpolator interpolator) {
+ mFinished = true;
+ mInterpolator = interpolator;
+ float ppi = context.getResources().getDisplayMetrics().density * 160.0f;
+ mDeceleration = 9.8f // g (m/s^2)
+ * 39.37f // inch/meter
+ * ppi // pixels per inch
+ * ViewConfiguration.getScrollFriction();
+ }
+
+ /**
+ *
+ * Returns whether the scroller has finished scrolling.
+ *
+ * @return True if the scroller has finished scrolling, false otherwise.
+ */
+ public final boolean isFinished() {
+ return mFinished;
+ }
+
+ /**
+ * Force the finished field to a particular value.
+ *
+ * @param finished The new finished value.
+ */
+ public final void forceFinished(boolean finished) {
+ mFinished = finished;
+ }
+
+ /**
+ * Returns how long the scroll event will take, in milliseconds.
+ *
+ * @return The duration of the scroll in milliseconds.
+ */
+ public final int getDuration() {
+ return mDuration;
+ }
+
+ /**
+ * 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 mCurrX;
+ }
+
+ /**
+ * 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 mCurrY;
+ }
+
+ /**
+ * Returns the start X offset in the scroll.
+ *
+ * @return The start X offset as an absolute distance from the origin.
+ * @hide pending API council
+ */
+ public final int getStartX() {
+ return mStartX;
+ }
+
+ /**
+ * Returns the start Y offset in the scroll.
+ *
+ * @return The start Y offset as an absolute distance from the origin.
+ * @hide pending API council
+ */
+ public final int getStartY() {
+ return mStartY;
+ }
+
+ /**
+ * 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 mFinalX;
+ }
+
+ /**
+ * 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 mFinalY;
+ }
+
+ /**
+ * Call this when you want to know the new location. If it returns true,
+ * the animation is not yet finished. loc will be altered to provide the
+ * new location.
+ */
+ public boolean computeScrollOffset() {
+ if (mFinished) {
+ return false;
+ }
+
+ int timePassed = (int)(AnimationUtils.currentAnimationTimeMillis() - mStartTime);
+
+ if (timePassed < mDuration) {
+ switch (mMode) {
+ case SCROLL_MODE:
+ float x = (float)timePassed * mDurationReciprocal;
+
+ if (mInterpolator == null)
+ x = viscousFluid(x);
+ else
+ x = mInterpolator.getInterpolation(x);
+
+ mCurrX = mStartX + Math.round(x * mDeltaX);
+ mCurrY = mStartY + Math.round(x * mDeltaY);
+ if ((mCurrX == mFinalX) && (mCurrY == mFinalY)) {
+ mFinished = true;
+ }
+ break;
+ case FLING_MODE:
+ float timePassedSeconds = timePassed / 1000.0f;
+ float distance = (mVelocity * timePassedSeconds)
+ - (mDeceleration * timePassedSeconds * timePassedSeconds / 2.0f);
+
+ mCurrX = mStartX + Math.round(distance * mCoeffX);
+ // Pin to mMinX <= mCurrX <= mMaxX
+ mCurrX = Math.min(mCurrX, mMaxX);
+ mCurrX = Math.max(mCurrX, mMinX);
+
+ mCurrY = mStartY + Math.round(distance * mCoeffY);
+ // Pin to mMinY <= mCurrY <= mMaxY
+ mCurrY = Math.min(mCurrY, mMaxY);
+ mCurrY = Math.max(mCurrY, mMinY);
+
+ if (mCurrX == mFinalX && mCurrY == mFinalY) {
+ mFinished = true;
+ }
+
+ break;
+ }
+ }
+ else {
+ mCurrX = mFinalX;
+ mCurrY = mFinalY;
+ mFinished = true;
+ }
+ return true;
+ }
+
+ /**
+ * Start scrolling by providing a starting point and the distance to travel.
+ * The scroll will use the default value of 250 milliseconds for the
+ * duration.
+ *
+ * @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.
+ */
+ public void startScroll(int startX, int startY, int dx, int dy) {
+ startScroll(startX, startY, dx, dy, DEFAULT_DURATION);
+ }
+
+ /**
+ * 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, int duration) {
+ mMode = SCROLL_MODE;
+ mFinished = false;
+ mDuration = duration;
+ mStartTime = AnimationUtils.currentAnimationTimeMillis();
+ mStartX = startX;
+ mStartY = startY;
+ mFinalX = startX + dx;
+ mFinalY = startY + dy;
+ mDeltaX = dx;
+ mDeltaY = dy;
+ mDurationReciprocal = 1.0f / (float) mDuration;
+ // This controls the viscous fluid effect (how much of it)
+ mViscousFluidScale = 8.0f;
+ // must be set to 1.0 (used in viscousFluid())
+ mViscousFluidNormalize = 1.0f;
+ mViscousFluidNormalize = 1.0f / viscousFluid(1.0f);
+ }
+
+ /**
+ * Start scrolling based on a fling gesture. The distance travelled 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.
+ * @param maxX Maximum X value. The scroller will not scroll past this
+ * point.
+ * @param minY Minimum Y value. The scroller will not scroll past this
+ * point.
+ * @param maxY Maximum Y value. The scroller will not scroll past this
+ * point.
+ */
+ public void fling(int startX, int startY, int velocityX, int velocityY,
+ int minX, int maxX, int minY, int maxY) {
+ mMode = FLING_MODE;
+ mFinished = false;
+
+ float velocity = (float)Math.hypot(velocityX, velocityY);
+
+ mVelocity = velocity;
+ mDuration = (int) (1000 * velocity / mDeceleration); // Duration is in
+ // milliseconds
+ mStartTime = AnimationUtils.currentAnimationTimeMillis();
+ mStartX = startX;
+ mStartY = startY;
+
+ mCoeffX = velocity == 0 ? 1.0f : velocityX / velocity;
+ mCoeffY = velocity == 0 ? 1.0f : velocityY / velocity;
+
+ int totalDistance = (int) ((velocity * velocity) / (2 * mDeceleration));
+
+ mMinX = minX;
+ mMaxX = maxX;
+ mMinY = minY;
+ mMaxY = maxY;
+
+
+ mFinalX = startX + Math.round(totalDistance * mCoeffX);
+ // Pin to mMinX <= mFinalX <= mMaxX
+ mFinalX = Math.min(mFinalX, mMaxX);
+ mFinalX = Math.max(mFinalX, mMinX);
+
+ mFinalY = startY + Math.round(totalDistance * mCoeffY);
+ // Pin to mMinY <= mFinalY <= mMaxY
+ mFinalY = Math.min(mFinalY, mMaxY);
+ mFinalY = Math.max(mFinalY, mMinY);
+ }
+
+
+
+ private float viscousFluid(float x)
+ {
+ x *= mViscousFluidScale;
+ 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 *= mViscousFluidNormalize;
+ return x;
+ }
+
+ /**
+ *
+ */
+ public void abortAnimation() {
+ mCurrX = mFinalX;
+ mCurrY = mFinalY;
+ mFinished = true;
+ }
+
+ /**
+ * Extend the scroll animation. This allows a running animation to
+ * scroll further and longer, when used with setFinalX() or setFinalY().
+ *
+ * @param extend Additional time to scroll in milliseconds.
+ */
+ public void extendDuration(int extend) {
+ int passed = timePassed();
+ mDuration = passed + extend;
+ mDurationReciprocal = 1.0f / (float)mDuration;
+ mFinished = false;
+ }
+
+ public int timePassed() {
+ return (int)(AnimationUtils.currentAnimationTimeMillis() - mStartTime);
+ }
+
+ public void setFinalX(int newX) {
+ mFinalX = newX;
+ mDeltaX = mFinalX - mStartX;
+ mFinished = false;
+ }
+
+ public void setFinalY(int newY) {
+ mFinalY = newY;
+ mDeltaY = mFinalY - mStartY;
+ mFinished = false;
+ }
+}