/// <summary>
/// Adds a NVG element to this view model.
/// </summary>
/// <param name="nvgElement">The NVG element which should be added.</param>
public void AddElement(INvgElement nvgElement)
{
if (null == nvgElement)
{
throw new ArgumentNullException(nameof(nvgElement));
}
_nvgElements.Add(nvgElement);
}
/// <summary>
/// Creates a new element position.
/// </summary>
/// <param name="element">The current element.</param>
/// <param name="elementTag">The element tag of the specified element.</param>
/// <param name="elementPosition">The previous element position.</param>
/// <returns>A new element position.</returns>
private static NvgElementPosition CreateElementPosition(INvgElement element, NvgElementTag elementTag, NvgElementPosition elementPosition)
{
return(new NvgElementPosition
{
Element = element,
ElementTag = elementTag,
PreviousElementPosition = elementPosition
});
}
/// <summary>
/// Reads the next NVG element from the stream.
/// </summary>
/// <returns>The next NVG element or <code>null</code> when there are no more NVG elements.</returns>
public INvgElement ReadNextElement()
{
NvgElementPosition elementPosition = null;
INvgElement element = null;
while (_xmlTextReader.Read())
{
switch (_xmlTextReader.NodeType)
{
case XmlNodeType.Element:
var startTag = new NvgElementTag(_xmlTextReader.LocalName);
if (startTag.IsNvgTag)
{
// Read the NVG element
element = new NvgElement();
element.ConstructFromReader(_xmlTextReader);
elementPosition = CreateElementPosition(element, startTag, elementPosition);
}
else if (startTag.IsGroupTag)
{
// Read the NVG group element
element = new NvgGroupElement();
element.ConstructFromReader(_xmlTextReader);
elementPosition = CreateElementPosition(element, startTag, elementPosition);
}
else if (startTag.IsPointTag)
{
// Read the NVG point element
element = new NvgPointElement();
element.ConstructFromReader(_xmlTextReader);
elementPosition = CreateElementPosition(element, startTag, elementPosition);
}
break;
case XmlNodeType.EndElement:
var endTag = new NvgElementTag(_xmlTextReader.LocalName);
// Add children and reset the position to the matching start tag
elementPosition = AddChildren(elementPosition, endTag);
if (null != elementPosition)
{
// Reset the current element to the start tag
element = elementPosition.Element;
}
if (endTag.IsNvgTag)
{
return(element);
}
break;
}
}
return(null);
}
private ulong ProcessAllMessages(INvgElement nvgElement, MessageLayer messageLayer)
{
ulong messageCount = 0;
var nvgPointElement = nvgElement as NvgPointElement;
if (TryProcessMessage(nvgPointElement, messageLayer))
{
messageCount++;
}
foreach (var nvgChildElement in nvgElement.Children)
{
messageCount += ProcessAllMessages(nvgChildElement, messageLayer);
}
return(messageCount);
}