/**
* <summary>Finds the location of the sublayers object in the specified configuration; in case no
* sublayers object is associated to this object, its virtual position is indicated.</summary>
* <param name="configuration">Configuration context.</param>
* <returns><code>null</code>, if this layer is outside the specified configuration.</returns>
*/
private LayersLocation FindLayersLocation(
LayerConfiguration configuration
)
{
/*
* NOTE: As layers are only weakly tied to configurations, their sublayers have to be sought
* through the configuration structure tree.
*/
PdfDirectObject levelLayerObject = null;
PdfArray levelObject = configuration.UILayers.BaseDataObject;
IEnumerator <PdfDirectObject> levelIterator = levelObject.GetEnumerator();
Stack <object[]> levelIterators = new Stack <object[]>();
PdfDirectObject thisObject = BaseObject;
PdfDirectObject currentLayerObject = null;
while (true)
{
if (!levelIterator.MoveNext())
{
if (levelIterators.Count == 0)
{
break;
}
object[] levelItems = levelIterators.Pop();
levelObject = (PdfArray)levelItems[0];
levelIterator = (IEnumerator <PdfDirectObject>)levelItems[1];
levelLayerObject = (PdfDirectObject)levelItems[2];
currentLayerObject = null;
}
else
{
PdfDirectObject nodeObject = levelIterator.Current;
PdfDataObject nodeDataObject = PdfObject.Resolve(nodeObject);
if (nodeDataObject is PdfDictionary)
{
if (nodeObject.Equals(thisObject))
{
/*
* NOTE: Sublayers are expressed as an array immediately following the parent layer node.
*/
return(new LayersLocation(levelLayerObject, levelObject, levelObject.IndexOf(thisObject) + 1, levelIterators));
}
currentLayerObject = nodeObject;
}
else if (nodeDataObject is PdfArray)
{
levelIterators.Push(new object[] { levelObject, levelIterator, levelLayerObject });
levelObject = (PdfArray)nodeDataObject;
levelIterator = levelObject.GetEnumerator();
levelLayerObject = currentLayerObject;
currentLayerObject = null;
}
}
}
return(null);
}
/**
* <summary>Gets the position of the initial base item corresponding to the specified layer
* state.</summary>
* <param name="item">Layer state.</param>
* <returns>-1, in case <code>item</code> has no match.</returns>
*/
internal int GetBaseIndex(
LayerState item
)
{
int baseIndex = -1;
{
PdfArray baseDataObject = BaseDataObject;
for (
int baseItemIndex = 0,
baseItemCount = baseDataObject.Count;
baseItemIndex < baseItemCount;
baseItemIndex++
)
{
PdfDirectObject baseItem = baseDataObject[baseItemIndex];
if (baseItem is PdfName &&
baseItem.Equals(item.Mode.GetName()))
{
foreach (Layer layer in item.Layers)
{
if (++baseItemIndex >= baseItemCount)
{
break;
}
baseItem = baseDataObject[baseItemIndex];
if (baseItem is PdfName ||
!baseItem.Equals(layer.BaseObject))
{
break;
}
}
}
}
}
return(baseIndex);
}