How to check for user inactivity with and without platform invokes in C#

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Timers;
using System.Windows.Forms;
using UserInactivityMonitoring;

namespace TestApplication
{
	public class MainForm : System.Windows.Forms.Form
	{
		private System.Windows.Forms.Button CreateCtrlMonButton;
		private System.ComponentModel.Container components = null;
		private System.Windows.Forms.TextBox OutputTextBox;
		private System.Windows.Forms.Button DisposeMonButton;
		private System.Windows.Forms.Button NullMonVarButton;
		private System.Windows.Forms.Button EnableMonButton;
		private System.Windows.Forms.Button DisableMonButton;
		private System.Windows.Forms.Button TriggerCGButton;
		private System.Windows.Forms.GroupBox CreateOptsGroup;
		private System.Windows.Forms.ComboBox MonTypeComboBox;
		private System.Windows.Forms.Label label1;
		private System.Windows.Forms.TextBox IntervalTextBox;
		private System.Windows.Forms.CheckBox SyncCheckBox;
		private System.Windows.Forms.CheckBox MonKeyboardCheckBox;
		private System.Windows.Forms.CheckBox MonMouseCheckBox;
		private System.Windows.Forms.Button ShowMsgBoxButton;
		private System.Windows.Forms.Button ShowOtherWindowButton;
		private System.Windows.Forms.CheckBox ModalWndCheckBox;

		private IInactivityMonitor inactivityMonitor = null;

		public MainForm()
		{
			InitializeComponent();
		}

		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if (components != null) 
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}

		#region Vom Windows Form-Designer generierter Code
		private void InitializeComponent()
		{
			this.CreateCtrlMonButton = new System.Windows.Forms.Button();
			this.OutputTextBox = new System.Windows.Forms.TextBox();
			this.DisposeMonButton = new System.Windows.Forms.Button();
			this.NullMonVarButton = new System.Windows.Forms.Button();
			this.EnableMonButton = new System.Windows.Forms.Button();
			this.DisableMonButton = new System.Windows.Forms.Button();
			this.TriggerCGButton = new System.Windows.Forms.Button();
			this.CreateOptsGroup = new System.Windows.Forms.GroupBox();
			this.MonMouseCheckBox = new System.Windows.Forms.CheckBox();
			this.MonKeyboardCheckBox = new System.Windows.Forms.CheckBox();
			this.SyncCheckBox = new System.Windows.Forms.CheckBox();
			this.MonTypeComboBox = new System.Windows.Forms.ComboBox();
			this.label1 = new System.Windows.Forms.Label();
			this.IntervalTextBox = new System.Windows.Forms.TextBox();
			this.ShowMsgBoxButton = new System.Windows.Forms.Button();
			this.ShowOtherWindowButton = new System.Windows.Forms.Button();
			this.ModalWndCheckBox = new System.Windows.Forms.CheckBox();
			this.CreateOptsGroup.SuspendLayout();
			this.SuspendLayout();
			// 
			// CreateCtrlMonButton
			// 
			this.CreateCtrlMonButton.Location = new System.Drawing.Point(8, 8);
			this.CreateCtrlMonButton.Name = "CreateCtrlMonButton";
			this.CreateCtrlMonButton.Size = new System.Drawing.Size(160, 24);
			this.CreateCtrlMonButton.TabIndex = 0;
			this.CreateCtrlMonButton.Text = "Create Monitor";
			this.CreateCtrlMonButton.Click += new System.EventHandler(this.CreateCtrlMonButton_Click);
			// 
			// OutputTextBox
			// 
			this.OutputTextBox.Location = new System.Drawing.Point(8, 280);
			this.OutputTextBox.Multiline = true;
			this.OutputTextBox.Name = "OutputTextBox";
			this.OutputTextBox.ScrollBars = System.Windows.Forms.ScrollBars.Both;
			this.OutputTextBox.Size = new System.Drawing.Size(512, 280);
			this.OutputTextBox.TabIndex = 10;
			this.OutputTextBox.Text = "";
			// 
			// DisposeMonButton
			// 
			this.DisposeMonButton.Location = new System.Drawing.Point(184, 8);
			this.DisposeMonButton.Name = "DisposeMonButton";
			this.DisposeMonButton.Size = new System.Drawing.Size(160, 24);
			this.DisposeMonButton.TabIndex = 1;
			this.DisposeMonButton.Text = "Dispose Monitor Object";
			this.DisposeMonButton.Click += new System.EventHandler(this.DisposeMonButton_Click);
			// 
			// NullMonVarButton
			// 
			this.NullMonVarButton.Location = new System.Drawing.Point(360, 8);
			this.NullMonVarButton.Name = "NullMonVarButton";
			this.NullMonVarButton.Size = new System.Drawing.Size(160, 24);
			this.NullMonVarButton.TabIndex = 2;
			this.NullMonVarButton.Text = "Null Monitor Variable";
			this.NullMonVarButton.Click += new System.EventHandler(this.NullMonVarButton_Click);
			// 
			// EnableMonButton
			// 
			this.EnableMonButton.Location = new System.Drawing.Point(8, 40);
			this.EnableMonButton.Name = "EnableMonButton";
			this.EnableMonButton.Size = new System.Drawing.Size(160, 24);
			this.EnableMonButton.TabIndex = 3;
			this.EnableMonButton.Text = "Enable Monitor";
			this.EnableMonButton.Click += new System.EventHandler(this.EnableMonButton_Click);
			// 
			// DisableMonButton
			// 
			this.DisableMonButton.Location = new System.Drawing.Point(184, 40);
			this.DisableMonButton.Name = "DisableMonButton";
			this.DisableMonButton.Size = new System.Drawing.Size(160, 24);
			this.DisableMonButton.TabIndex = 4;
			this.DisableMonButton.Text = "Disable Monitor";
			this.DisableMonButton.Click += new System.EventHandler(this.DisableMonButton_Click);
			// 
			// TriggerCGButton
			// 
			this.TriggerCGButton.Location = new System.Drawing.Point(360, 40);
			this.TriggerCGButton.Name = "TriggerCGButton";
			this.TriggerCGButton.Size = new System.Drawing.Size(160, 24);
			this.TriggerCGButton.TabIndex = 5;
			this.TriggerCGButton.Text = "Collect Garbage";
			this.TriggerCGButton.Click += new System.EventHandler(this.TriggerCGButton_Click);
			// 
			// CreateOptsGroup
			// 
			this.CreateOptsGroup.Controls.Add(this.MonMouseCheckBox);
			this.CreateOptsGroup.Controls.Add(this.MonKeyboardCheckBox);
			this.CreateOptsGroup.Controls.Add(this.SyncCheckBox);
			this.CreateOptsGroup.Controls.Add(this.MonTypeComboBox);
			this.CreateOptsGroup.Controls.Add(this.label1);
			this.CreateOptsGroup.Controls.Add(this.IntervalTextBox);
			this.CreateOptsGroup.Location = new System.Drawing.Point(8, 160);
			this.CreateOptsGroup.Name = "CreateOptsGroup";
			this.CreateOptsGroup.Size = new System.Drawing.Size(512, 100);
			this.CreateOptsGroup.TabIndex = 9;
			this.CreateOptsGroup.TabStop = false;
			this.CreateOptsGroup.Text = "Creation Options";
			// 
			// MonMouseCheckBox
			// 
			this.MonMouseCheckBox.Location = new System.Drawing.Point(360, 64);
			this.MonMouseCheckBox.Name = "MonMouseCheckBox";
			this.MonMouseCheckBox.TabIndex = 5;
			this.MonMouseCheckBox.Text = "Monitor Mouse";
			// 
			// MonKeyboardCheckBox
			// 
			this.MonKeyboardCheckBox.Location = new System.Drawing.Point(176, 64);
			this.MonKeyboardCheckBox.Name = "MonKeyboardCheckBox";
			this.MonKeyboardCheckBox.Size = new System.Drawing.Size(120, 24);
			this.MonKeyboardCheckBox.TabIndex = 4;
			this.MonKeyboardCheckBox.Text = "Monitor Keyboard";
			// 
			// SyncCheckBox
			// 
			this.SyncCheckBox.Location = new System.Drawing.Point(16, 64);
			this.SyncCheckBox.Name = "SyncCheckBox";
			this.SyncCheckBox.Size = new System.Drawing.Size(128, 24);
			this.SyncCheckBox.TabIndex = 3;
			this.SyncCheckBox.Text = "Synchronize Events";
			// 
			// MonTypeComboBox
			// 
			this.MonTypeComboBox.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
			this.MonTypeComboBox.Location = new System.Drawing.Point(16, 24);
			this.MonTypeComboBox.Name = "MonTypeComboBox";
			this.MonTypeComboBox.Size = new System.Drawing.Size(168, 21);
			this.MonTypeComboBox.TabIndex = 0;
			// 
			// label1
			// 
			this.label1.AutoSize = true;
			this.label1.Location = new System.Drawing.Point(248, 24);
			this.label1.Name = "label1";
			this.label1.Size = new System.Drawing.Size(118, 16);
			this.label1.TabIndex = 1;
			this.label1.Text = "Interval in milliseconds";
			// 
			// IntervalTextBox
			// 
			this.IntervalTextBox.Location = new System.Drawing.Point(368, 24);
			this.IntervalTextBox.Name = "IntervalTextBox";
			this.IntervalTextBox.TabIndex = 2;
			this.IntervalTextBox.Text = "1000";
			// 
			// ShowMsgBoxButton
			// 
			this.ShowMsgBoxButton.Location = new System.Drawing.Point(184, 88);
			this.ShowMsgBoxButton.Name = "ShowMsgBoxButton";
			this.ShowMsgBoxButton.Size = new System.Drawing.Size(160, 24);
			this.ShowMsgBoxButton.TabIndex = 7;
			this.ShowMsgBoxButton.Text = "Show Message Box";
			this.ShowMsgBoxButton.Click += new System.EventHandler(this.ShowMsgBoxButton_Click);
			// 
			// ShowOtherWindowButton
			// 
			this.ShowOtherWindowButton.Location = new System.Drawing.Point(8, 88);
			this.ShowOtherWindowButton.Name = "ShowOtherWindowButton";
			this.ShowOtherWindowButton.Size = new System.Drawing.Size(160, 24);
			this.ShowOtherWindowButton.TabIndex = 6;
			this.ShowOtherWindowButton.Text = "Show Some Other Window";
			this.ShowOtherWindowButton.Click += new System.EventHandler(this.ShowOtherWindowButton_Click);
			// 
			// ModalWndCheckBox
			// 
			this.ModalWndCheckBox.Location = new System.Drawing.Point(8, 120);
			this.ModalWndCheckBox.Name = "ModalWndCheckBox";
			this.ModalWndCheckBox.Size = new System.Drawing.Size(136, 24);
			this.ModalWndCheckBox.TabIndex = 8;
			this.ModalWndCheckBox.Text = "Show modal Window";
			// 
			// MainForm
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
			this.ClientSize = new System.Drawing.Size(530, 567);
			this.Controls.Add(this.ModalWndCheckBox);
			this.Controls.Add(this.ShowOtherWindowButton);
			this.Controls.Add(this.ShowMsgBoxButton);
			this.Controls.Add(this.CreateOptsGroup);
			this.Controls.Add(this.TriggerCGButton);
			this.Controls.Add(this.DisableMonButton);
			this.Controls.Add(this.EnableMonButton);
			this.Controls.Add(this.NullMonVarButton);
			this.Controls.Add(this.DisposeMonButton);
			this.Controls.Add(this.OutputTextBox);
			this.Controls.Add(this.CreateCtrlMonButton);
			this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedDialog;
			this.MaximizeBox = false;
			this.Name = "MainForm";
			this.Text = "Inactivity Monitor Test Application";
			this.Load += new System.EventHandler(this.MainForm_Load);
			this.CreateOptsGroup.ResumeLayout(false);
			this.ResumeLayout(false);

		}
		#endregion

		[STAThread]
		static void Main() 
		{
			try
			{
				Application.Run(new MainForm());
			}
			catch (Exception e)
			{
				MessageBox.Show(e.Message);
			}
		}

		private void TimeElapsed(object sender, ElapsedEventArgs e)
		{
			try
			{
				if (this.InvokeRequired)
					WriteOutput("Event 'Elapsed' occured (Invoke() would have been required)");
				else
					WriteOutput("Event 'Elapsed' occured (synchronized call)");
			}
			catch (Exception exception)
			{
				WriteOutput("Exception occured: " + exception.Message);
			}
		}

		private void Reactivated(object sender, EventArgs e)
		{
			try
			{
				if (this.InvokeRequired)
					WriteOutput("Event 'Reactivated' occured (Invoke() would have been required)");
				else
					WriteOutput("Event 'Reactivated' occured (synchronized call)");
			}
			catch (Exception exception)
			{
				WriteOutput("Exception occured: " + exception.Message);
			}
		}

		private void CreateCtrlMonButton_Click(object sender, System.EventArgs e)
		{
			try
			{
				switch (MonTypeComboBox.SelectedIndex)
				{
					case 0:
						inactivityMonitor = MonitorCreator.CreateInstance(this, MonitorType.ControlMonitor);
						WriteOutput("New 'ControlMonitor' created");
						break;
					case 1:
						inactivityMonitor = MonitorCreator.CreateInstance(MonitorType.ApplicationMonitor);
						WriteOutput("New 'ApplicationMonitor' created");
						break;
					case 2:
						inactivityMonitor = MonitorCreator.CreateInstance(MonitorType.LastInputMonitor);
						WriteOutput("New 'LastInputMonitor' created");
						break;
					case 3:
						inactivityMonitor = MonitorCreator.CreateInstance(MonitorType.ThreadHookMonitor);
						WriteOutput("New local 'HookMonitor' created");
						break;
					case 4:
						inactivityMonitor = MonitorCreator.CreateInstance(MonitorType.GlobalHookMonitor);
						WriteOutput("New global 'HookMonitor' created");
						break;
					default:
						WriteOutput("Unknown monitor type (" + MonTypeComboBox.SelectedText + ")");
						return;
				}
				if (SyncCheckBox.Checked)
					inactivityMonitor.SynchronizingObject = this;
				if (!MonKeyboardCheckBox.Checked)
					inactivityMonitor.MonitorKeyboardEvents = false;
				if (!MonMouseCheckBox.Checked)
					inactivityMonitor.MonitorMouseEvents = false;
				inactivityMonitor.Interval = Convert.ToDouble(IntervalTextBox.Text);
				inactivityMonitor.Elapsed += new ElapsedEventHandler(TimeElapsed);
				inactivityMonitor.Reactivated += new EventHandler(Reactivated);
			}
			catch (Exception exception)
			{
				WriteOutput("Exception occured: " + exception.Message);
			}
		}

		private void WriteOutput(string output)
		{
			OutputTextBox.Text += output + "\r\n";
			OutputTextBox.SelectionStart = OutputTextBox.Text.Length;
			OutputTextBox.ScrollToCaret();
		}

		private void DisposeMonButton_Click(object sender, System.EventArgs e)
		{
			try
			{
				inactivityMonitor.Dispose();
				WriteOutput("Monitor object disposed");
			}
			catch (Exception exception)
			{
				WriteOutput("Exception occured: " + exception.Message);
			}
		}

		private void NullMonVarButton_Click(object sender, System.EventArgs e)
		{
			try
			{
				inactivityMonitor = null;
				WriteOutput("Set monitor object variable to null");
			}
			catch (Exception exception)
			{
				WriteOutput("Exception occured: " + exception.Message);
			}
		}

		private void MainForm_Load(object sender, System.EventArgs e)
		{
			MonTypeComboBox.Items.Add(typeof(ControlMonitor).Name);
			MonTypeComboBox.Items.Add(typeof(ApplicationMonitor).Name);
			MonTypeComboBox.Items.Add(typeof(LastInputMonitor).Name);
			MonTypeComboBox.Items.Add(typeof(HookMonitor).Name + " (local)");
			MonTypeComboBox.Items.Add(typeof(HookMonitor).Name + " (global)");
			MonTypeComboBox.SelectedIndex = 0;
		}

		private void EnableMonButton_Click(object sender, System.EventArgs e)
		{
			try
			{
				inactivityMonitor.Enabled = true;
				WriteOutput("Monitor enabled");
			}
			catch (Exception exception)
			{
				WriteOutput("Exception occured: " + exception.Message);
			}
		}

		private void DisableMonButton_Click(object sender, System.EventArgs e)
		{
			try
			{
				inactivityMonitor.Enabled = false;
				WriteOutput("Monitor disabled");
			}
			catch (Exception exception)
			{
				WriteOutput("Exception occured: " + exception.Message);
			}
		}

		private void TriggerCGButton_Click(object sender, System.EventArgs e)
		{
			try
			{
				GC.Collect();
				WriteOutput("Collected garbage");
			}
			catch (Exception exception)
			{
				WriteOutput("Exception occured: " + exception.Message);
			}		
		}

		private void ShowMsgBoxButton_Click(object sender, System.EventArgs e)
		{
			MessageBox.Show("fhqwhgads");
		}

		private void ShowOtherWindowButton_Click(object sender, System.EventArgs e)
		{
			if (ModalWndCheckBox.Checked)
				new SomeOtherForm().ShowDialog(this);
			else
				new SomeOtherForm().Show();
		}
	}
}