diff options
| -rw-r--r-- | core/java/android/widget/OverScroller.java | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/core/java/android/widget/OverScroller.java b/core/java/android/widget/OverScroller.java index 451e493..98bfd7d 100644 --- a/core/java/android/widget/OverScroller.java +++ b/core/java/android/widget/OverScroller.java @@ -731,7 +731,7 @@ public class OverScroller { // mStartTime has been set mFinished = false; mState = CUBIC; - mStart = start; + mCurrentPosition = mStart = start; mFinal = end; final int delta = start - end; mDeceleration = getDeceleration(delta); @@ -797,7 +797,9 @@ public class OverScroller { 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); + // The float cast below is necessary to avoid integer overflow. + final float velocitySquared = (float) velocity * velocity; + final float distanceToApex = velocitySquared / 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)); @@ -848,12 +850,14 @@ public class OverScroller { 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)); + // The float cast below is necessary to avoid integer overflow. + final float velocitySquared = (float) mVelocity * mVelocity; + float distance = velocitySquared / (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); + mDeceleration = - sign * velocitySquared / (2.0f * mOver); distance = mOver; } |