/// <summary>
/// Invoked to indicate that the Source needs to be closed.
/// </summary>
/// <exception cref="DataSourceException"></exception>
protected virtual void OnCloseDSReq()
{
for (var _rc = DataSourceServices.DsmInvoke(this.AppIdentity, TwMSG.CloseDSReq); _rc != TwRC.Success;)
{
throw new DataSourceException(TwRC.Failure, TwCC.OperationError);
}
}
/// <summary>
/// Every Source is required to have a single entry point called DS_Entry. DS_Entry is only called by the Source Manager.
/// </summary>
/// <param name="appId">This points to a TwIdentity structure, allocated by the application, that describes the
/// application making the call. One of the fields in this structure, called Id, is an arbitrary and
/// unique identifier assigned by the Source Manager to tag the application as a unique TWAIN
/// entity. The Source Manager maintains a copy of the application’s identity structure, so the
/// application must not modify that structure unless it first breaks its connection with the Source
/// Manager,then reconnects to cause the Source Manager to store the new, modified identity.</param>
/// <param name="dg">The Data Group of the operation triplet. Currently, only DG_CONTROL, DG_IMAGE, and DG_AUDIO are defined.</param>
/// <param name="dat">The Data Argument Type of the operation triplet.</param>
/// <param name="msg">The Message of the operation triplet.</param>
/// <param name="data">The pData parameter is a pointer to the data (a variable or, more
/// typically, a structure) that will be used according to the action specified by the operation
/// triplet.</param>
/// <returns>TWAIN Return Codes.</returns>
public TwRC ProcessRequest(TwIdentity appId, TwDG dg, TwDAT dat, TwMSG msg, IntPtr data)
{
try {
if (dg == TwDG.Control)
{
switch (dat)
{
case TwDAT.Identity:
return(this._IdentityControlProcessRequest(appId, msg, data));
case TwDAT.Status:
return(this._StatusControlProcessRequest(appId, msg, data));
case TwDAT.EntryPoint:
return(this._EntryPointControlProcessRequest(appId, msg, Marshal.PtrToStructure(data, typeof(TwEntryPoint)) as TwEntryPoint));
}
}
this._SetConditionCode(appId, TwCC.Success);
return(this._handlers[appId.Id].ProcessRequest(dg, dat, msg, data));
} catch (DataSourceException ex) {
DataSourceServices._ToLog(ex);
this._SetConditionCode(appId, ex.ConditionCode);
return(ex.ReturnCode);
} catch (Exception ex) {
DataSourceServices._ToLog(ex);
}
this._SetConditionCode(appId, TwCC.OperationError);
return(TwRC.Failure);
}
/// <summary>
/// Invoked to indicate that the Source has data that is ready to be transferred.
/// </summary>
/// <exception cref="DataSourceException"></exception>
protected virtual void OnXferReady()
{
if (this.XferEnvironment.PendingXfers == 0)
{
this.XferEnvironment.PendingXfers = (ushort)Math.Abs((short)this[TwCap.XferCount].Value);
}
this.State |= DataSourceState.Ready;
for (var _rc = DataSourceServices.DsmInvoke(this.AppIdentity, TwMSG.XFerReady); _rc != TwRC.Success;)
{
this.State &= ~DataSourceState.Ready;
this.XferEnvironment.PendingXfers = 0;
throw new DataSourceException(TwRC.Failure, TwCC.OperationError);
}
}
