protected override void SetLoadingState(XslFOViewerControlState loadingState)
{
this.SuspendLayout();
try
{
//Due to UI Control Issues we must HIDE and Re-Show the control
//to ensure that the UI is always updated. Therefore we simply always
//Hide and then only if appropriate do we re-show the control.
if (_ctlAcrobatPdfViewer != null)
{
_ctlAcrobatPdfViewer.Hide();
}
//Always reset the following Timers
lblPreLoaderTimer.Hide();
animLoaderTimerText.Stop();
_loadingStopwatch.Stop();
preLoaderTimer.Stop();
//Always reset the following UI Visible elements
panelPreLoader.Hide();
panelInitInstructions.Hide();
//Now handle the correct state for Pre-Loader
if (loadingState == XslFOViewerControlState.Loading && _ctlAcrobatPdfViewer != null)
{
//Loading State is IN PROGRESS
panelPreLoader.Show();
_loadingStopwatch.Restart();
lblPreLoaderTimer.Text = "";
preLoaderTimer.Start();
//Kick off the Pre-Load Timer Text animation
TaskScheduler.FromCurrentSynchronizationContext().DelayExecution(TimeSpan.FromSeconds(3), () =>
{
lblPreLoaderTimer.ForeColor = animLoaderTimerText.StartColor;
lblPreLoaderTimer.Show();
animLoaderTimerText.Start(false);
});
}
else if (loadingState == XslFOViewerControlState.LoadCompleted && _ctlAcrobatPdfViewer != null)
{
//Update the UI since it is re-set after the Load
//Due to COM issues we need to ensure that all calls to the underlying Ctl are property Try/Catch wrapped.
this._ctlAcrobatPdfViewer.Show();
//The control will maliciously grab focus until after it has completely finished loading
//the Pdf file. There is no Event for us to monitor so instead we simply implement a standard
//acceptable wait period.
//NOTE: The process is to re-set the controls original Enabled state after the wait period has elapsed
// so we execute a background thread to perform the wait and then trigger the update back on the UI
// thread. This ensures that our UI is not interrupted.
//NOTE: Stop and Restart the delay timer so that it will run after a FULL Delay
tmrAcrobatLoadDelay.Stop();
tmrAcrobatLoadDelay.Start();
}
else if (loadingState == XslFOViewerControlState.Unloaded && _ctlAcrobatPdfViewer != null)
{
//By default we have hidden all elements including the PreLoader and Unavailble Instructions
//therefore we do nothing here when the status is simply Unloaded.
}
else if (loadingState == XslFOViewerControlState.Unavailable || _ctlAcrobatPdfViewer == null)
{
//IF the Acrobat Pdf Viewer is unable to be Initialized or is Unloaded we handle it here!
//NOTE: If NOT Initialized we must show the Initialize Error Instructions.
panelInitInstructions.Show();
}
}
catch (Exception exc)
{
System.Diagnostics.Debug.WriteLine("Error Trapped Refreshing UI Elements -- {0}".FormatArgs(exc.GetMessages()));
}
finally
{
Thread.Yield();
this.ResumeLayout(true);
}
}
protected virtual void SetLoadingState(XslFOViewerControlState loadingState)
{
throw new NotImplementedException("Inheriting Control Must Implement this Method! It is not marked Abstract due to Visual Studio Designer issues.");
}
