greenshot/GreenshotPlugin/Controls/PleaseWaitForm.cs

/*
 * Greenshot - a free and open source screenshot tool
 * Copyright (C) 2007-2016 Thomas Braun, Jens Klingen, Robin Krom
 * 
 * For more information see: http://getgreenshot.org/
 * The Greenshot project is hosted on GitHub https://github.com/greenshot/greenshot
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 1 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
using System;
using System.Windows.Forms;
using System.Threading;
using GreenshotPlugin.Core;
using log4net;

namespace GreenshotPlugin.Controls {
	/// <summary>
	/// Description of PleaseWaitForm.
	/// </summary>
	public partial class PleaseWaitForm : Form {
		private static readonly ILog LOG = LogManager.GetLogger(typeof(PleaseWaitForm));
		private Thread _waitFor;
		private string _title;
		public PleaseWaitForm() {
			//
			// The InitializeComponent() call is required for Windows Forms designer support.
			//
			InitializeComponent();
			Icon = GreenshotResources.getGreenshotIcon();
		}
		
		/// <summary>
		/// Prevent the close-window button showing
		/// </summary>
		private const int CP_NOCLOSE_BUTTON = 0x200;
		protected override CreateParams CreateParams {
			get {
				CreateParams createParams = base.CreateParams;
				createParams.ClassStyle = createParams.ClassStyle | CP_NOCLOSE_BUTTON ;
				return createParams;
			}
		} 
		
		/// <summary>
		/// Show the "please wait" form, execute the code from the delegate and wait until execution finishes.
		/// The supplied delegate will be wrapped with a try/catch so this method can return any exception that was thrown.
		/// </summary>
		/// <param name="title">The title of the form (and Thread)</param>
		/// <param name="text">The text in the form</param>
		/// <param name="waitDelegate">delegate { with your code }</param>
		public void ShowAndWait(string title, string text, ThreadStart waitDelegate) {
			_title = title;
			Text = title;
			label_pleasewait.Text = text;
			cancelButton.Text = Language.GetString("CANCEL");

			// Make sure the form is shown.
			Show();
			
			// Variable to store the exception, if one is generated, from inside the thread.
			Exception threadException = null;
			try {
				// Wrap the passed delegate in a try/catch which makes it possible to save the exception
				_waitFor = new Thread(new ThreadStart(
						delegate
						{
							try
							{
								waitDelegate.Invoke();
							}
							catch (Exception ex)
							{
								LOG.Error("invoke error:", ex);
								threadException = ex;
							}
						})
				)
				{
					Name = title,
					IsBackground = true
				};
				_waitFor.SetApartmentState(ApartmentState.STA);
				_waitFor.Start();
	
				// Wait until finished
				while (!_waitFor.Join(TimeSpan.FromMilliseconds(100))) {
					Application.DoEvents();
				}
				LOG.DebugFormat("Finished {0}", title);
			} catch (Exception ex) {
				LOG.Error(ex);
				throw;
			} finally {
				Close();
			}
			// Check if an exception occured, if so throw it
			if (threadException != null) {
				throw threadException;
			}
		}
		
		/// <summary>
		/// Called if the cancel button is clicked, will use Thread.Abort()
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void CancelButtonClick(object sender, EventArgs e) {
			LOG.DebugFormat("Cancel clicked on {0}", _title);
			cancelButton.Enabled = false;
			_waitFor.Abort();
		}
	}
}