private void InternalLoadState(ProcessStateOption processOption, Stream inputStream)
{
if (!_initialized)
{
throw new InvalidOperationException("Layout State Persister not initialized");
}
if (inputStream == null)
{
throw new ArgumentNullException(nameof(inputStream));
}
if (processOption.HasFlag(ProcessStateOption.DocumentsOnly) && processOption.HasFlag(ProcessStateOption.ToolsOnly) ||
processOption.HasFlag(ProcessStateOption.Complete) && (processOption.HasFlag(ProcessStateOption.ToolsOnly) ||
processOption.HasFlag(ProcessStateOption.ToolsOnly)))
{
throw new InvalidEnumArgumentException();
}
var layoutItems = new Dictionary <string, ILayoutItemBase>();
try
{
using (var reader = new BinaryReader(inputStream))
{
var count = reader.ReadInt32();
for (var i = 0; i < count; i++)
{
var typeName = reader.ReadString();
var contentId = reader.ReadString();
var stateEndPosition = reader.ReadInt64();
stateEndPosition += reader.BaseStream.Position;
var contentType = Type.GetType(typeName);
var skipStateData = true;
if (contentType != null)
{
if (IoC.GetInstance(contentType, null) is ILayoutItemBase contentInstance)
{
if (contentInstance is ITool && !processOption.HasFlag(ProcessStateOption.DocumentsOnly) ||
contentInstance is ILayoutItem && !processOption.HasFlag(ProcessStateOption.ToolsOnly))
{
layoutItems.Add(contentId, contentInstance);
}
try
{
contentInstance.LoadState(reader);
skipStateData = false;
}
catch
{
skipStateData = true;
}
}
}
// Skip state data block if we couldn't read it.
if (skipStateData)
{
reader.BaseStream.Seek(stateEndPosition, SeekOrigin.Begin);
}
}
if (layoutItems.Count == 0)
{
if (processOption == ProcessStateOption.DocumentsOnly || processOption == ProcessStateOption.DocumentsOnly)
{
_dockingHostViewModel.LayoutItems.Clear();
}
if (processOption == ProcessStateOption.ToolsOnly ||
processOption == ProcessStateOption.Complete)
{
_dockingHostViewModel.Tools.Clear();
}
return;
}
var active = _dockingHostViewModel.ActiveItem;
_dockingHostViewModel.LoadLayout(reader.BaseStream, _dockingHostViewModel.ShowTool, _dockingHostViewModel.OpenLayoutItem, layoutItems);
if (_dockingHostViewModel.LayoutItems.Contains(active))
{
_dockingHostViewModel.OpenLayoutItem(active);
}
}
}
catch
{
inputStream.Close();
}
}
private void InternalSaveState(ProcessStateOption processOption, Stream inputStream)
{
if (!_initialized)
{
throw new InvalidOperationException();
}
if (inputStream == null)
{
throw new ArgumentNullException(nameof(inputStream));
}
if (processOption.HasFlag(ProcessStateOption.DocumentsOnly) && processOption.HasFlag(ProcessStateOption.ToolsOnly) ||
processOption.HasFlag(ProcessStateOption.Complete) && (processOption.HasFlag(ProcessStateOption.ToolsOnly) ||
processOption.HasFlag(ProcessStateOption.ToolsOnly)))
{
throw new InvalidEnumArgumentException();
}
try
{
var writer = new BinaryWriter(inputStream);
var itemStates = _dockingHostViewModel.LayoutItems.Concat(_dockingHostViewModel.Tools.Cast <ILayoutItemBase>());
var itemCount = 0;
// reserve some space for items count, it'll be updated later
writer.Write(itemCount);
foreach (var item in itemStates)
{
if (item is ILayoutItem && processOption.HasFlag(ProcessStateOption.ToolsOnly))
{
continue;
}
if (item is ITool && processOption.HasFlag(ProcessStateOption.DocumentsOnly))
{
continue;
}
if (processOption.HasFlag(ProcessStateOption.UseShouldReopenOnStart) && !item.ShouldReopenOnStart)
{
continue;
}
var itemType = item.GetType();
var exportAttributes = itemType
.GetCustomAttributes(typeof(ExportAttribute), false)
.Cast <ExportAttribute>()
.ToList();
var layoutType = typeof(ILayoutItemBase);
// get exports with explicit types or names that inherit from ILayoutItemBase
var exportTypes = (from att in exportAttributes
// select the contract type if it is of type ILayoutitem. else null
let typeFromContract = att.ContractType != null &&
layoutType.IsAssignableFrom(att.ContractType)
? att.ContractType
: null
// select the contract name if it is of type ILayoutItemBase. else null
let typeFromQualifiedName = GetTypeFromContractNameAsILayoutItem(att)
// select the viewmodel type if it is of type ILayoutItemBase. else null
let typeFromViewModel =
layoutType.IsAssignableFrom(itemType) ? itemType : null
// att.ContractType overrides att.ContractName if both are set.
// fall back to the ViewModel type of neither are defined.
let type = typeFromContract ?? typeFromQualifiedName ?? typeFromViewModel
where type != null
select type).ToList();
// throw exceptions here, instead of failing silently. These are design time errors.
var firstExport = exportTypes.FirstOrDefault();
if (firstExport == null)
{
throw new InvalidOperationException(
$"A ViewModel that participates in LayoutItem.ShouldReopenOnStart must be decorated with an ExportAttribute who's ContractType that inherits from ILayoutItemBase, infringing type is {itemType}.");
}
if (exportTypes.Count > 1)
{
throw new InvalidOperationException(
$"A ViewModel that participates in LayoutItem.ShouldReopenOnStart can't be decorated with more than one ExportAttribute which inherits from ILayoutItemBase. infringing type is {itemType}.");
}
var selectedTypeName = firstExport.AssemblyQualifiedName;
if (string.IsNullOrEmpty(selectedTypeName))
{
throw new InvalidOperationException(
$"Could not retrieve the assembly qualified type name for {firstExport}, most likely because the type is generic.");
}
// TODO: it is possible to save generic types. It requires that every generic parameter is saved, along with its position in the generic tree... A lot of work.
writer.Write(selectedTypeName);
writer.Write(item.ContentId);
// Here's the tricky part. Because some items might fail to save their state, or they might be removed (a plug-in assembly deleted and etc.)
// we need to save the item's state size to be able to skip the data during deserialization.
// Save current stream position. We'll need it later.
var stateSizePosition = writer.BaseStream.Position;
// Reserve some space for item state size
writer.Write(0L);
long stateSize;
try
{
var stateStartPosition = writer.BaseStream.Position;
item.SaveState(writer);
stateSize = writer.BaseStream.Position - stateStartPosition;
}
catch
{
stateSize = 0;
}
// Go back to the position before item's state and write the actual value.
writer.BaseStream.Seek(stateSizePosition, SeekOrigin.Begin);
writer.Write(stateSize);
if (stateSize > 0)
{
writer.BaseStream.Seek(0, SeekOrigin.End);
}
itemCount++;
}
writer.BaseStream.Seek(0, SeekOrigin.Begin);
writer.Write(itemCount);
writer.BaseStream.Seek(0, SeekOrigin.End);
_dockingHostViewModel.SaveLayout(writer.BaseStream);
}
catch
{
inputStream.Close();
}
}