public DataSourceManager(Identity applicationId, IWindowsMessageHook messageHook)
{
// Make a copy of the identity in case it gets modified
ApplicationId = applicationId.Clone();
ScanningComplete += delegate { };
TransferImage += delegate { };
_messageHook = messageHook;
_messageHook.FilterMessageCallback = FilterMessage;
IntPtr windowHandle = _messageHook.WindowHandle;
_eventMessage.EventPtr = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(WindowsMessage)));
// Initialise the data source manager
TwainResult result = Twain32Native.DsmParent(
ApplicationId,
IntPtr.Zero,
DataGroup.Control,
DataArgumentType.Parent,
Message.OpenDSM,
ref windowHandle);
if (result == TwainResult.Success)
{
//according to the 2.0 spec (2-10) if (applicationId.SupportedGroups
// | DataGroup.Dsm2) > 0 then we should call DM_Entry(id, 0, DG_Control, DAT_Entrypoint, MSG_Get, wh)
//right here
DataSource = DataSource.GetDefault(ApplicationId, _messageHook);
}
else
{
throw new TwainException("Error initialising DSM: " + result, result);
}
}
public static List<DataSource> GetAllSources(Identity applicationId, IWindowsMessageHook messageHook)
{
var sources = new List<DataSource>();
Identity id = new Identity();
// Get the first source
var result = Twain32Native.DsmIdentity(
applicationId,
IntPtr.Zero,
DataGroup.Control,
DataArgumentType.Identity,
Message.GetFirst,
id);
if (result == TwainResult.EndOfList)
{
return sources;
}
else if (result != TwainResult.Success)
{
throw new TwainException("Error getting first source.", result);
}
else
{
sources.Add(new DataSource(applicationId, id, messageHook));
}
while (true)
{
// Get the next source
result = Twain32Native.DsmIdentity(
applicationId,
IntPtr.Zero,
DataGroup.Control,
DataArgumentType.Identity,
Message.GetNext,
id);
if (result == TwainResult.EndOfList)
{
break;
}
else if (result != TwainResult.Success)
{
throw new TwainException("Error enumerating sources.", result);
}
sources.Add(new DataSource(applicationId, id, messageHook));
}
return sources;
}
public DataSource(Identity applicationId, Identity sourceId, IWindowsMessageHook messageHook)
{
_applicationId = applicationId;
SourceId = sourceId.Clone();
_messageHook = messageHook;
}
public static DataSource UserSelected(Identity applicationId, IWindowsMessageHook messageHook)
{
var defaultSourceId = new Identity();
// Show the TWAIN interface to allow the user to select a source
Twain32Native.DsmIdentity(
applicationId,
IntPtr.Zero,
DataGroup.Control,
DataArgumentType.Identity,
Message.UserSelect,
defaultSourceId);
return new DataSource(applicationId, defaultSourceId, messageHook);
}
public static DataSource GetSource(string sourceProductName, Identity applicationId, IWindowsMessageHook messageHook)
{
// A little slower than it could be, if enumerating unnecessary sources is slow. But less code duplication.
foreach (var source in GetAllSources(applicationId, messageHook))
{
if (sourceProductName.Equals(source.SourceId.ProductName, StringComparison.InvariantCultureIgnoreCase))
{
return source;
}
}
return null;
}
public static DataSource GetDefault(Identity applicationId, IWindowsMessageHook messageHook)
{
var defaultSourceId = new Identity();
// Attempt to get information about the system default source
var result = Twain32Native.DsmIdentity(
applicationId,
IntPtr.Zero,
DataGroup.Control,
DataArgumentType.Identity,
Message.GetDefault,
defaultSourceId);
if (result != TwainResult.Success)
{
return null;
//var status = DataSourceManager.GetConditionCode(applicationId, null);
//throw new TwainException("Error getting information about the default source: " + result, result, status);
}
return new DataSource(applicationId, defaultSourceId, messageHook);
}
public static ConditionCode GetConditionCode(Identity applicationId, Identity sourceId)
{
Status status = new Status();
Twain32Native.DsmStatus(
applicationId,
sourceId,
DataGroup.Control,
DataArgumentType.Status,
Message.Get,
status);
return status.ConditionCode;
}
