SwipeRefreshLayout.java 文件源码

@Override
public void applyTransformation(float interpolatedTime, Transformation t) {
    int targetTop = 0;
    int endTarget = 0;
    if (!mUsingCustomStart) {
        switch (mDirection) {
            case BOTTOM:
                endTarget = getMeasuredHeight() - (int) (mSpinnerFinalOffset);
                break;
            case TOP:
            default:
                endTarget = (int) (mSpinnerFinalOffset - Math.abs(mOriginalOffsetTop));
                break;
        }
    } else {
        endTarget = (int) mSpinnerFinalOffset;
    }
    targetTop = (mFrom + (int) ((endTarget - mFrom) * interpolatedTime));
    int offset = targetTop - mCircleView.getTop();
    setTargetOffsetTopAndBottom(offset, false /* requires update */);
}