///<summary>
/// Find the next occurence of the byte pattern. Works asynchronously.
///</summary>
public IAsyncResult FindNext(AsyncCallback ac)
{
if (dataBook.NPages == 0 || inUse)
{
FindNextOperation op = new FindNextOperation(strategy, null, FindAsyncCallback);
return(HandleProblematicOp(op, ac));
}
inUse = true;
userFindAsyncCallback = ac;
findFinishedEvent.Reset();
// if this is the first time we are checking
// for a valid pattern, emit the event
if (firstTime == true && strategy.Pattern.Length > 0)
{
firstTime = false;
if (FirstFind != null)
{
FirstFind();
}
} // is pattern acceptable?
else if (strategy.Pattern.Length == 0)
{
return(null);
}
DataView dv = ((DataViewDisplay)dataBook.CurrentPageWidget).View;
strategy.Buffer = dv.Buffer;
// decide where to start searching from
if (!dv.Selection.IsEmpty())
{
strategy.Position = dv.Selection.Start + 1;
}
else
{
strategy.Position = dv.CursorOffset;
}
SetUpFindProgressReport();
FindNextOperation fno = new FindNextOperation(strategy, progressCallback, FindAsyncCallback);
// lock the buffer, so user can't modify it while
// searching
strategy.Buffer.ModifyAllowed = false;
strategy.Buffer.FileOperationsAllowed = false;
// start find thread
Thread findThread = new Thread(fno.OperationThread);
findThread.IsBackground = true;
findThread.Start();
return(new ThreadedAsyncResult(fno, findFinishedEvent, false));
}
public KeyValuePair <IData, IData>?FindNext(IData key)
{
var operation = new FindNextOperation(key);
Execute(operation);
return(operation.KeyValue);
}
private void WriteFindNextOperation(BinaryWriter writer, FindNextOperation operation)
{
KeyPersist.Write(writer, operation.FromKey);
writer.Write(operation.KeyValue.HasValue);
if (operation.KeyValue.HasValue)
{
KeyPersist.Write(writer, operation.KeyValue.Value.Key);
RecordPersist.Write(writer, operation.KeyValue.Value.Value);
}
}
void FindNextAsyncCallback(IAsyncResult ar)
{
ThreadedAsyncResult tar = (ThreadedAsyncResult)ar;
FindNextOperation state = (FindNextOperation)tar.AsyncState;
if (state.Result == FindNextOperation.OperationResult.Finished && state.Match == null)
{
InformationAlert ia = new InformationAlert(Catalog.GetString("The pattern you requested was not found."), Catalog.GetString("End of file reached."), mainWindow);
ia.Run();
ia.Destroy();
}
}
void FindNextAsyncCallback(IAsyncResult ar)
{
ThreadedAsyncResult tar = (ThreadedAsyncResult)ar;
FindNextOperation state = (FindNextOperation)tar.AsyncState;
if (state.Result == FindNextOperation.OperationResult.Finished && state.Match == null)
{
InformationAlert ia = new InformationAlert("The pattern you requested was not found.", "End of file reached.", null);
ia.Run();
ia.Destroy();
}
this.Sensitive = true;
this.Visible = false;
this.Visible = true;
}
