/** Destroy shadow wrapper for currently pinned view */
public void DestroyPinnedShadow()
{
// keep shadow for being recycled later
mRecycleShadow = mPinnedShadow;
mPinnedShadow = null;
}
/** Create shadow wrapper with a pinned view for a view at given position */
private void CreatePinnedShadow(int position)
{
// try to recycle shadow
PinnedViewShadow pinnedShadow = mRecycleShadow;
mRecycleShadow = null;
// create new shadow, if needed
if (pinnedShadow == null)
pinnedShadow = new PinnedViewShadow ();
// request new view using recycled view, if such
View pinnedView = Adapter.GetView (position, pinnedShadow.View, this);
// read layout parameters
LayoutParams layoutParams = (LayoutParams)pinnedView.LayoutParameters;
int heightSize;
MeasureSpecMode heightMode;
if (layoutParams == null) { // take care for missing layout parameters
heightMode = MeasureSpecMode.AtMost;
heightSize = Height;
} else {
heightMode = MeasureSpec.GetMode (layoutParams.Height);
heightSize = MeasureSpec.GetSize (layoutParams.Height);
}
if (heightMode == MeasureSpecMode.Unspecified)
heightMode = MeasureSpecMode.Exactly;
int maxHeight = Height - ListPaddingTop - ListPaddingBottom;
if (heightSize > maxHeight)
heightSize = maxHeight;
// measure & layout
int ws = MeasureSpec.MakeMeasureSpec (Width - ListPaddingLeft - ListPaddingRight, MeasureSpecMode.Exactly);
int hs = MeasureSpec.MakeMeasureSpec (heightSize, heightMode);
pinnedView.Measure (ws, hs);
pinnedView.Layout (0, 0, pinnedView.MeasuredWidth, pinnedView.MeasuredHeight);
mTranslateY = 0;
// initialize pinned shadow
pinnedShadow.Position = position;
pinnedShadow.View = pinnedView;
// store pinned shadow
mPinnedShadow = pinnedShadow;
}
