@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
final int parentLeft = getPaddingLeft();
final int parentRight = right - left - getPaddingRight();
final int parentTop = getPaddingTop();
final int parentBottom = bottom - top - getPaddingBottom();
if (mScrollView != null && mScrollView.getVisibility() != GONE) {
final FrameLayout.LayoutParams lp = (FrameLayout.LayoutParams) mScrollView.getLayoutParams();
final int width = mScrollView.getMeasuredWidth();
final int height = mScrollView.getMeasuredHeight();
int childLeft;
int childTop;
int gravity = lp.gravity;
if (gravity == -1) {
gravity = DEFAULT_CHILD_GRAVITY;
}
final int horizontalGravity = gravity & Gravity.HORIZONTAL_GRAVITY_MASK;
final int verticalGravity = gravity & Gravity.VERTICAL_GRAVITY_MASK;
switch (horizontalGravity) {
case Gravity.LEFT:
childLeft = parentLeft + lp.leftMargin;
break;
case Gravity.CENTER_HORIZONTAL:
childLeft =
parentLeft + (parentRight - parentLeft - width) / 2 + lp.leftMargin - lp.rightMargin;
break;
case Gravity.RIGHT:
childLeft = parentRight - width - lp.rightMargin;
break;
default:
childLeft = parentLeft + lp.leftMargin;
}
switch (verticalGravity) {
case Gravity.TOP:
childTop = parentTop + lp.topMargin;
break;
case Gravity.CENTER_VERTICAL:
childTop =
parentTop + (parentBottom - parentTop - height) / 2 + lp.topMargin - lp.bottomMargin;
break;
case Gravity.BOTTOM:
childTop = parentBottom - height - lp.bottomMargin;
break;
default:
childTop = parentTop + lp.topMargin;
}
mScrollView.layout(childLeft, childTop, childLeft + width, childTop + height);
}
if (mBackground != null) {
final int scrollYCenterOffset = -mScrollView.getScrollY();
final int offset = (int) (scrollYCenterOffset * mScrollDiff);
// Log.d(TAG, "Layout Scroll Y: " + scrollYCenterOffset +
// " ScrollDiff: " + mScrollDiff
// + " Background Offset:" + offset);
mBackground.layout(getLeft(), offset, mBackgroundRight, offset + mBackgroundBottom);
}
}
