ImageScraper/MainWindow.cs

using System;
using System.IO;
using System.ComponentModel;
using System.Threading;
using Gtk;
using Scraper;

public partial class MainWindow: Gtk.Window
{	
	ModelController model;
	Thread thread;
	string overallProgress = "Overall Progress";
	
	public MainWindow (ModelController model): base (Gtk.WindowType.Toplevel)
	{
		Build ();
		this.model = model;
	}
	
	protected void OnDeleteEvent (object sender, DeleteEventArgs a)
	{		
		Application.Invoke (delegate {
			if (model.Active) {
				model.CancelTask ();	
			}			
			Application.Quit ();
			a.RetVal = true;	
		});
		
	}
	
	protected void OnInputUrlChanged (object sender, System.EventArgs e)
	{
		if (!model.Active) {
			Reset ();	
		}		
	}
	
	protected void OnNumberValueChanged (object sender, System.EventArgs e)
	{
		if (!model.Active) {
			Reset ();	
		}		
	}
	
	protected void OnScrapeButtonClicked (object sender, System.EventArgs e)
	{		
		var number = int.Parse (NumberButton.Text);
		var inputUrl = UrlEntry.Text;
		string outputFileName;
				
		thread = new Thread (this.model.RunTask);
		
		if (!model.Active) {
			
			if (SaveDialog (out outputFileName)) {
				
				// validate and run
				bool valid = false;
				try {
					valid = model.ValidateInputs (inputUrl, outputFileName, number);	
				} catch (Exception ex) {
					ErrorAlert (ex.Message);					
				}
				if (valid) {
										
					model.TaskStarted += OnTaskStarted;
					model.TaskCancelled += OnTaskCancelled;
					model.TaskCompleted += OnTaskCompleted;
					model.FileProgress += OnIndividualProgressUpdate;
					model.FileDownloaded += OnOverallProgressUpdate;
										
					OverallProgressBar.Fraction = 0;
			
					thread.Start ();
				} 
				
			} else {				
				return;
			}
			
		} else {						
			model.CancelTask ();
		}
	}
	
	protected void OnTaskStarted (object sender, EventArgs e)
	{
		Application.Invoke (delegate {
			IndividualProgressLabel.Text = String.Format ("Individual Progress: {0}", model.Status.ToLower ());
			ScrapeButton.Label = "Cancel";
		});
	}

	protected void OnTaskCompleted (object sender, EventArgs e)
	{
		// Gtk.Application.Invoke makes sure that these events are handled on the Gtk main thread
		// otherwise they would be invoked on the thread where the event was invoked.
		// Thus we are not touching the UI from background threads.
		Application.Invoke (delegate {
			IndividualProgressBar.Fraction = 1.0;
			IndividualProgressLabel.Text = String.Format ("Individual Progress: {0}", model.Status.ToLower ());
			OverallProgressBar.Fraction = 1.0;
			OverallProgressLabel.Text = String.Format ("{0}: 100%", overallProgress);
			ScrapeButton.Label = "Scrape";			
			FinishedAlert ();
		});		
	}
	
	protected void OnTaskCancelled (object sender, EventArgs e)
	{	
		Application.Invoke (delegate {
			IndividualProgressLabel.Text = String.Format ("Individual Progress: {0}", model.Status.ToLower ());
			ScrapeButton.Label = "Scrape";		
		});
	}
	
	protected void OnOverallProgressUpdate (object sender, EventArgs e)
	{
		Application.Invoke (delegate {			
			if (model.Active) {
				// 100% individual progress
				IndividualProgressBar.Fraction = 1.0;		
				IndividualProgressLabel.Text = String.Format ("Individual Progress: {0}", model.Status.ToLower ());
		
				// update overall progress
				double frac = (double)model.NumberDownloaded / (double)model.NumberToDownload;
				OverallProgressBar.Fraction = frac;
				OverallProgressLabel.Text = String.Format ("{0}: {1}%", overallProgress, Math.Round (100 * frac));
		
				// 0% individual progress
//				IndividualProgressBar.Fraction = 0;	
			}
		});
	}
	
	protected void OnIndividualProgressUpdate (object sender, ProgressChangedEventArgs e)
	{
		Application.Invoke (delegate {
			if (model.Active) {
				IndividualProgressBar.Fraction = e.ProgressPercentage / (double)100;	
			}
		});
		
	}
	
	protected void Reset ()
	{
		IndividualProgressBar.Fraction = 0;
		IndividualProgressLabel.Text = "Individual Progress";
		OverallProgressBar.Fraction = 0;
		OverallProgressLabel.Text = "Overall Progress";
		ScrapeButton.Label = "Scrape";
	}
	
	protected bool SaveDialog (out string outputFileName)
	{
		var chooser = new FileChooserDialog ("Save as...", 
		                                     this, 
		                                     FileChooserAction.Save, 
		                                     Stock.Save, 
		                                     ResponseType.Ok, 
		                                     Stock.Cancel, 
		                                     ResponseType.Cancel);
		
		// present dialog
		chooser.DoOverwriteConfirmation = true;
		chooser.ShowHidden = false;
		var ans = chooser.Run () == (int)ResponseType.Ok;				
		var temp = chooser.Filename;		
		chooser.Destroy ();
		outputFileName = temp;
		return ans;
	}
	
	protected void FinishedAlert ()
	{
		var md = new MessageDialog (this,
		                           DialogFlags.DestroyWithParent,
		                           MessageType.Info,
		                           ButtonsType.Ok,
		                           "Scraping finished!");
		md.Run ();
		md.Destroy ();
	}
	
	protected void ErrorAlert (string message)
	{
		var md = new MessageDialog (this,
		                           DialogFlags.DestroyWithParent,
		                           MessageType.Warning,
		                           ButtonsType.Ok,
		                           message);
		md.Run ();
		md.Destroy ();
	}
	
	// text entries (including spin buttons) invoke Activate on enter key hit 
	protected void OnActivated (object sender, System.EventArgs e)
	{
		if (sender.GetType () == typeof(Gtk.SpinButton)) {
			ScrapeButton.Click ();
		} else if (sender.GetType () == typeof(Gtk.Entry)) {
			NumberButton.GrabFocus ();
		} else {
			// pass
		}
	
	}
}