private void moveSpinner(float overscrollTop) {
mProgress.showArrow(true);
float originalDragPercent = overscrollTop / mTotalDragDistance;
float dragPercent = Math.min(1f, Math.abs(originalDragPercent));
float adjustedPercent = (float) Math.max(dragPercent - .4, 0) * 5 / 3;
float extraOS = Math.abs(overscrollTop) - mTotalDragDistance;
float slingshotDist =
mUsingCustomStart ? mSpinnerFinalOffset - mOriginalOffsetTop : mSpinnerFinalOffset;
float tensionSlingshotPercent =
Math.max(0, Math.min(extraOS, slingshotDist * 2) / slingshotDist);
float tensionPercent =
(float) ((tensionSlingshotPercent / 4) - Math.pow((tensionSlingshotPercent / 4), 2)) * 2f;
float extraMove = (slingshotDist) * tensionPercent * 2;
int targetY = mOriginalOffsetTop + (int) ((slingshotDist * dragPercent) + extraMove);
// where 1.0f is a full circle
if (mCircleView.getVisibility() != View.VISIBLE) {
mCircleView.setVisibility(View.VISIBLE);
}
if (!mScale) {
ViewCompat.setScaleX(mCircleView, 1f);
ViewCompat.setScaleY(mCircleView, 1f);
}
if (overscrollTop < mTotalDragDistance) {
if (mScale) {
setAnimationProgress(overscrollTop / mTotalDragDistance);
}
if (mProgress.getAlpha() > STARTING_PROGRESS_ALPHA
&& !isAnimationRunning(mAlphaStartAnimation)) {
// Animate the alpha
startProgressAlphaStartAnimation();
}
float strokeStart = adjustedPercent * .8f;
mProgress.setStartEndTrim(0f, Math.min(MAX_PROGRESS_ANGLE, strokeStart));
mProgress.setArrowScale(Math.min(1f, adjustedPercent));
} else {
if (mProgress.getAlpha() < MAX_ALPHA && !isAnimationRunning(mAlphaMaxAnimation)) {
// Animate the alpha
startProgressAlphaMaxAnimation();
}
}
float rotation = (-0.25f + .4f * adjustedPercent + tensionPercent * 2) * .5f;
mProgress.setProgressRotation(rotation);
setTargetOffsetTopAndBottom(targetY - mCurrentTargetOffsetTop, true /* requires update */);
}
private void startScaleDownReturnToStartAnimation(
int from, Animation.AnimationListener listener) {
mFrom = from;
if (isAlphaUsedForScale()) {
mStartingScale = mProgress.getAlpha();
} else {
mStartingScale = ViewCompat.getScaleX(mCircleView);
}
mScaleDownToStartAnimation =
new Animation() {
@Override
public void applyTransformation(float interpolatedTime, Transformation t) {
float targetScale = (mStartingScale + (-mStartingScale * interpolatedTime));
setAnimationProgress(targetScale);
moveToStart(interpolatedTime);
}
};
mScaleDownToStartAnimation.setDuration(SCALE_DOWN_DURATION);
if (listener != null) {
mCircleView.setAnimationListener(listener);
}
mCircleView.clearAnimation();
mCircleView.startAnimation(mScaleDownToStartAnimation);
}
private void startProgressAlphaMaxAnimation() {
mAlphaMaxAnimation = startAlphaAnimation(mProgress.getAlpha(), MAX_ALPHA);
}
private void startProgressAlphaStartAnimation() {
mAlphaStartAnimation = startAlphaAnimation(mProgress.getAlpha(), STARTING_PROGRESS_ALPHA);
}