/// <summary>
/// Fill a row.
/// </summary>
/// <param name="markerLine"> Line indicating the top edge of the row. </param>
/// <param name="anchorPosition"> Position of the first view in the row. </param>
/// <param name="direction"> Direction of edge to fill towards. </param>
/// <param name="measureRowItems"> Measure the row items. </param>
/// <param name="sd"> Section data. </param>
/// <param name="state"> Layout state. </param>
/// <returns> The height of the new row. </returns>
public int fillRow(int markerLine, int anchorPosition, LayoutManager.Direction direction, bool measureRowItems, SectionData sd, LayoutState state)
{
int rowHeight = 0;
LayoutState.View[] views = new LayoutState.View[mNumColumns];
for (int i = 0; i < mNumColumns; i++)
{
int position = anchorPosition + i;
if (position >= state.recyclerState.ItemCount)
{
break;
}
LayoutState.View view = state.GetView(position);
if (view.LayoutParams.FirstPosition != sd.firstPosition)
{
state.CacheView(position, view.view);
break;
}
if (measureRowItems)
{
MeasureChild(view, sd);
}
else
{
state.DecacheView(i + anchorPosition);
}
rowHeight = Math.Max(rowHeight, mLayoutManager.GetDecoratedMeasuredHeight(view.view));
views[i] = view;
}
bool directionIsStart = direction == LayoutManager.Direction.START;
if (directionIsStart)
{
markerLine -= rowHeight;
}
for (int i = 0; i < mNumColumns; i++)
{
int col = directionIsStart ? mNumColumns - i - 1 : i;
if (views[col] == null)
{
continue;
}
LayoutChild(views[col], markerLine, col, rowHeight, sd, state);
AddView(views[col], col + anchorPosition, direction, state);
}
return(rowHeight);
}
protected int AddView(LayoutState.View child, int position, LayoutManager.Direction direction, LayoutState state)
{
int addIndex;
if (direction == LayoutManager.Direction.START)
{
addIndex = 0;
}
else
{
addIndex = mLayoutManager.ChildCount;
}
state.DecacheView(position);
mLayoutManager.AddView(child.view, addIndex);
return(addIndex);
}
public override int FillToStart(int leadingEdge, int markerLine, int anchorPosition, SectionData sd, LayoutState state)
{
// Check to see if we have to adjust for minimum section height. We don't if there is an
// attached non-header view in this section.
bool applyMinHeight = false;
for (int i = 0; i < state.recyclerState.ItemCount; i++)
{
View check = mLayoutManager.GetChildAt(0);
if (check == null)
{
applyMinHeight = false;
break;
}
LayoutManager.LayoutParams checkParams = (LayoutManager.LayoutParams)check.LayoutParameters;
if (checkParams.FirstPosition != sd.firstPosition)
{
applyMinHeight = true;
break;
}
if (!checkParams.isHeader)
{
applyMinHeight = false;
break;
}
}
// Work out offset to marker line by measuring items from the end. If section height is less
// than min height, then adjust marker line and then lay out items.
int measuredPositionsMarker = -1;
int sectionHeight = 0;
int minHeightOffset = 0;
if (applyMinHeight)
{
for (int i = anchorPosition; i >= 0; i--)
{
LayoutState.View measure = state.GetView(i);
state.CacheView(i, measure.view);
LayoutManager.LayoutParams lp = measure.LayoutParams;
if (lp.FirstPosition != sd.firstPosition)
{
break;
}
if (lp.isHeader)
{
continue;
}
measureChild(measure, sd);
sectionHeight += mLayoutManager.GetDecoratedMeasuredHeight(measure.view);
measuredPositionsMarker = i;
if (sectionHeight >= sd.minimumHeight)
{
break;
}
}
if (sectionHeight < sd.minimumHeight)
{
minHeightOffset = sectionHeight - sd.minimumHeight;
markerLine += minHeightOffset;
}
}
for (int i = anchorPosition; i >= 0; i--)
{
if (markerLine - minHeightOffset < leadingEdge)
{
break;
}
LayoutState.View next = state.GetView(i);
LayoutManager.LayoutParams lp = next.LayoutParams;
if (lp.isHeader)
{
state.CacheView(i, next.view);
break;
}
if (lp.FirstPosition != sd.firstPosition)
{
state.CacheView(i, next.view);
break;
}
if (!applyMinHeight || i < measuredPositionsMarker)
{
measureChild(next, sd);
}
else
{
state.DecacheView(i);
}
markerLine = layoutChild(next, markerLine, LayoutManager.Direction.START, sd, state);
AddView(next, i, LayoutManager.Direction.START, state);
}
return(markerLine);
}