/// <summary>
/// Saves the given root element to the given stream as AXML.
/// </summary>
/// <param name="stream">Stream to save to</param>
/// <param name="rootElement">Root element of the document</param>
public static void SaveDocument(Stream stream, AxmlElement rootElement)
{
BinaryWriter mainOutput = new BinaryWriter(stream);
// Write the main elements chunk of the file to a MemoryStream first
SavingContext ctx = new SavingContext();
rootElement.PrepareResourceIndices(ctx);
rootElement.Save(ctx);
MemoryStream mainChunkStream = (MemoryStream)ctx.Writer.BaseStream;
string[] stringPool = ctx.StringPool.Save();
int[] resourcePool = ctx.ResourcePool.Save();
int stringPoolLength = StringPool.CalculatePoolLength(stringPool);
int stringPoolPadding = 4 - stringPoolLength % 4;
stringPoolLength += stringPoolPadding; // Add padding to four bytes
int resourcePoolLength = resourcePool.Length * 4; // Each pool item is an integer
// The length of the main xml tag is that of the whole file, so also including the string pool, resource pool, and main chunk. (+ extra 8 + 8 = 16 bytes for string pool and resource pool header)
mainOutput.WriteChunkHeader(ResourceType.Xml, stringPoolLength + resourcePoolLength + (int)mainChunkStream.Position + 16);
mainOutput.WriteChunkHeader(ResourceType.StringPool, stringPoolLength);
StringPool.SaveStringPool(stringPool, mainOutput);
for (int i = 0; i < stringPoolPadding; i++)
{
mainOutput.Write((byte)0);
}
mainOutput.WriteChunkHeader(ResourceType.XmlResourceMap, resourcePoolLength);
foreach (int resource in resourcePool)
{
mainOutput.Write(resource);
}
// Save the main chunk of the file
mainChunkStream.Position = 0;
mainChunkStream.CopyTo(stream);
}
/// <summary>
/// Loads an AXML document from the given stream.
/// The stream must be seekable.
/// </summary>
/// <param name="stream">The stream to load from, must be seekable</param>
/// <returns></returns>
/// <exception cref="ArgumentException">If the given stream is not seekable</exception>
/// <exception cref="AxmlParseException">Any errors in the AXML format of the file</exception>
public static AxmlElement LoadDocument(Stream stream)
{
if (!stream.CanSeek)
{
throw new ArgumentException("Cannot read axml from non-seekable stream");
}
BinaryReader input = new BinaryReader(stream);
if (input.ReadResourceType() != ResourceType.Xml)
{
throw new AxmlParseException("Initial tag was not xml");
}
int fileSize = input.ReadInt32();
string[]? stringPool = null;
int[]? resourceMap = null;
Stack <AxmlElement> elementStack = new Stack <AxmlElement>();
List <QueuedNamespace> queuedNamespaces = new List <QueuedNamespace>();
AxmlElement? rootElement = null;
int preChunkPosition = 8; // Already gone past two ints for initial XML tag and file size
while (preChunkPosition < fileSize)
{
ResourceType chunkType = input.ReadResourceType();
int chunkLength = input.ReadInt32();
if (stringPool == null && chunkType != ResourceType.StringPool)
{
throw new AxmlParseException("String pool must be located after Xml tag");
}
int currentLineNumber;
switch (chunkType)
{
// The string pool must come before any elements, a check for this is above
case ResourceType.StringPool:
stringPool = StringPool.LoadStringPool(input);
break;
case ResourceType.XmlResourceMap:
// Divide by 4 because the resource map is made up of integers, subtract 2 for the resource type and length values
int resourceCount = chunkLength / 4 - 2;
resourceMap = new int[resourceCount];
for (int i = 0; i < resourceCount; i++)
{
resourceMap[i] = input.ReadInt32();
}
break;
case ResourceType.XmlStartNamespace:
input.ReadInt32(); // Line number, currently unused
if (input.ReadUInt32() != 0xFFFFFFFF)
{
throw new AxmlParseException("Expected 0xFFFFFFFF");
}
Debug.Assert(stringPool != null);
int prefixId = input.ReadInt32();
string?prefix = prefixId == -1 ? null : stringPool[prefixId];
string uriString = stringPool[input.ReadInt32()];
Uri uri = ParseNamespaceUri(uriString);
queuedNamespaces.Add(new QueuedNamespace(prefix, uri));
break;
case ResourceType.XmlEndNamespace:
break;
case ResourceType.XmlStartElement:
currentLineNumber = input.ReadInt32();
if (input.ReadUInt32() != 0xFFFFFFFF)
{
throw new AxmlParseException("Expected 0xFFFFFFFF");
}
Debug.Assert(stringPool != null);
int namespaceId = input.ReadInt32(); // -1 means no namespace prefix, so default namespace
string elementName = stringPool[input.ReadInt32()];
if (input.ReadUInt32() != 0x00140014)
{
throw new AxmlParseException("Expected 0x00140014");
}
AxmlElement childElement = new AxmlElement(elementName, namespaceId == -1 ? null : ParseNamespaceUri(stringPool[namespaceId]), currentLineNumber);
int numAttributes = input.ReadInt16();
int idAttributeIndex = input.ReadInt16() - 1;
int classAttributeIndex = input.ReadInt16() - 1;
int styleAttributeIndex = input.ReadInt16() - 1;
for (int i = 0; i < numAttributes; i++)
{
int attrNamespaceId = input.ReadInt32();
Uri?attrNamespace = attrNamespaceId == -1 ? null : ParseNamespaceUri(stringPool[attrNamespaceId]);
int attrNameAndResourceIdIndex = input.ReadInt32();
string attrName = stringPool[attrNameAndResourceIdIndex];
int? attrResourceId = null;
if (resourceMap == null)
{
throw new AxmlParseException(
$"Attempted to access resource ID with index {attrNameAndResourceIdIndex} when the resource pool chunk had not yet been received");
}
if (attrNameAndResourceIdIndex >= 0 && attrNameAndResourceIdIndex < resourceMap.Length)
{
attrResourceId = resourceMap[attrNameAndResourceIdIndex];
}
int attrRawStringIndex = input.ReadInt32();
AttributeType attrType = (AttributeType)(input.ReadInt32() >> 24); // The first byte contains the actual type, so we shift this to the right
int attrRawValue = input.ReadInt32();
object value;
if (i == idAttributeIndex)
{
value = new WrappedValue(WrappedValueType.Id, stringPool[attrRawStringIndex], attrRawValue);
}
else if (i == classAttributeIndex)
{
value = new WrappedValue(WrappedValueType.Class, stringPool[attrRawStringIndex], attrRawValue);
}
else if (i == styleAttributeIndex)
{
value = new WrappedValue(WrappedValueType.Style, stringPool[attrRawStringIndex], attrRawValue);
}
else if (attrType == AttributeType.Reference)
{
value = new WrappedValue(WrappedValueType.Reference, null, attrRawValue);
}
else if (attrType == AttributeType.String)
{
value = stringPool[attrRawValue];
}
else if (attrType == AttributeType.Boolean)
{
value = attrRawValue != 0;
}
else
{
value = attrRawValue;
}
childElement.Attributes.Add(new AxmlAttribute(attrName, attrNamespace, attrResourceId, value, attrType));
}
// Add the namespaces of any parent StartNamespace resources to this element
foreach (QueuedNamespace ns in queuedNamespaces)
{
if (ns.Prefix == null) // No prefix means that this is a default namespace
{
childElement.DeclaredDefaultNamespace = ns.Uri;
}
else
{
childElement.DeclaredNamespaces[ns.Prefix] = ns.Uri;
}
}
queuedNamespaces.Clear();
// Add the child element to the current bottom-most element in the stack.
if (elementStack.Count == 0)
{
if (rootElement != null)
{
throw new AxmlParseException("Document contained multiple root elements");
}
rootElement = childElement;
}
else
{
elementStack.Peek().Children.Add(childElement);
}
// Set this element as the bottom-most element
elementStack.Push(childElement);
break;
case ResourceType.XmlEndElement:
elementStack.Pop(); // Current bottom-most element is now the next element up
break;
case ResourceType.XmlCdata:
input.ReadInt32(); // Line number, currently unused
if (input.ReadUInt32() != 0xFFFFFFFF)
{
throw new AxmlParseException("Expected 0xFFFFFFFF");
}
input.ReadInt32(); // TODO: ID of "text" value. Currently unused
// TODO: Unused bytes. (figure out what they are)
input.ReadInt32();
input.ReadInt32();
break;
default:
throw new AxmlParseException("Unknown chunk type: " + chunkType);
}
input.BaseStream.Position = preChunkPosition + chunkLength;
preChunkPosition = (int)input.BaseStream.Position;
}
if (rootElement == null)
{
throw new AxmlParseException("Document did not contain a root element");
}
return(rootElement);
}
