/// <summary>
/// Function to load a single dependency for a file.
/// </summary>
/// <param name="dependency">Dependency to load.</param>
/// <param name="childDependencies">The dependencies for this dependency.</param>
/// <returns>The loaded dependency object.</returns>
private object LoadDependency(GorgonEditorDependency dependency, IReadOnlyDictionary <GorgonEditorDependency, object> childDependencies)
{
GorgonFileSystemFileEntry dependencyFile = FileSystem.GetFile(dependency.Path);
if (dependencyFile == null)
{
throw new IOException(string.Format(Resources.GORFS_ERR_DEPENDENCY_NOT_FOUND, dependency.Path));
}
// Find a handler for this file.
KeyValuePair <Type, Func <Stream, IReadOnlyDictionary <GorgonEditorDependency, object>, object> > handler =
_fileHandlers.FirstOrDefault(item =>
string.Equals(item.Key.FullName,
dependency.Type,
StringComparison.OrdinalIgnoreCase));
if (handler.Key == null)
{
throw new IOException(string.Format(Resources.GORFS_ERR_FILE_NO_HANDLER, dependency.Path));
}
using (Stream dependencyStream = dependencyFile.OpenStream(false))
{
return(handler.Value(dependencyStream, childDependencies));
}
}
/// <summary>
/// Function to load a file from the editor file.
/// </summary>
/// <typeparam name="T">The type of object to load. Must be a reference type.</typeparam>
/// <param name="path">Path to the file to load.</param>
/// <remarks>
/// Use this method to load a file from the file system generated by the editor. The type parameter T is used to determine how to load an object through a registered type loader.
/// <para>The type loader is registered by supplying a type and a function to read in the file. This allows the developer to load in their own file formats if required. New loader types
/// can be added through the <see cref="RegisteredEditorTypes"/> parameter.</para>
/// <para>Without adding any new loader types Gorgon will support loading of its supported image codecs, sprites (for the 2D renderer), animations and fonts. The loader will attempt to load
/// any dependencies required by the requested file as well.</para>
/// </remarks>
public T ReadFile <T>(string path)
where T : class
{
if (path == null)
{
throw new ArgumentNullException("path");
}
if (string.IsNullOrWhiteSpace(path))
{
throw new ArgumentException(Resources.GORFS_ERR_PARAMETER_MUST_NOT_BE_EMPTY, "path");
}
Type type = typeof(T);
Func <Stream, IReadOnlyDictionary <GorgonEditorDependency, object>, object> loader;
if (!_fileHandlers.TryGetValue(type, out loader))
{
throw new IOException(string.Format(Resources.GORFS_ERR_FILE_NO_HANDLER, path));
}
GorgonFileSystemFileEntry file = FileSystem.GetFile(path);
if (file == null)
{
throw new IOException(string.Format(Resources.GORFS_ERR_FILE_NOT_FOUND, path));
}
// Load the meta data if it's not been loaded yet.
if (_hasMetaData == null)
{
GetDependencies();
}
GorgonEditorDependencyCollection dependencies;
IReadOnlyDictionary <GorgonEditorDependency, object> dependencyObjects = new Dictionary <GorgonEditorDependency, object>();
// Check to see if the file has dependencies.
if (Dependencies.TryGetValue(file.FullPath, out dependencies))
{
dependencyObjects = LoadDependencies(dependencies);
}
using (Stream fileStream = file.OpenStream(false))
{
return((T)loader(fileStream, dependencyObjects));
}
}
/// <summary>
/// Function to retrieve the dependencies file and process it.
/// </summary>
private void GetDependencies()
{
if ((_hasMetaData != null) &&
(!_hasMetaData.Value))
{
return;
}
// If we've already loaded the file system meta data for this file system, then leave.
if (_metaDataFile != null)
{
return;
}
GorgonFileSystemFileEntry file = FileSystem.GetFile(MetaDataFile);
if (file == null)
{
_hasMetaData = false;
return;
}
// Create and load the object.
using (Stream metaFile = file.OpenStream(false))
{
_metaDataFile = XDocument.Load(metaFile);
}
XElement rootNode = _metaDataFile.Element(MetaDataRootName);
if (rootNode == null)
{
_hasMetaData = false;
return;
}
XElement dependencyNode = rootNode.Element(ContentDependencyFiles);
if (dependencyNode == null)
{
_hasMetaData = false;
return;
}
IEnumerable <XElement> fileNodes = dependencyNode.Elements(FileNode);
var dependencies = new Dictionary <string, GorgonEditorDependencyCollection>();
// Lock here because we're updating a collection that's not thread safe.
foreach (XElement fileNode in fileNodes)
{
XAttribute path = fileNode.Attribute(NameAttr);
if ((path == null) ||
(string.IsNullOrWhiteSpace(path.Value)))
{
continue;
}
dependencies.Add(path.Value,
GorgonEditorDependencyCollection
.Deserialize(fileNode.Elements(GorgonEditorDependency.DependencyNode)));
}
Dependencies = dependencies;
_hasMetaData = Dependencies.Count > 0;
}
