Move Process list manager into a separate class

Eve-O-Preview/Services/Implementation/ProcessMonitor.cs

@@ -0,0 +1,93 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+
+namespace EveOPreview.Services.Implementation
+{
+	sealed class ProcessMonitor : IProcessMonitor
+	{
+		#region Private constants
+		private const string DefaultProcessName = "ExeFile";
+		#endregion
+
+		#region Private fields
+		private readonly IDictionary<IntPtr, string> _processCache;
+		#endregion
+
+		public ProcessMonitor()
+		{
+			this._processCache = new Dictionary<IntPtr, string>(512);
+		}
+
+		private bool IsMonitoredProcess(string processName)
+		{
+			// This is a possible extension point
+			return String.Equals(processName, ProcessMonitor.DefaultProcessName, StringComparison.OrdinalIgnoreCase);
+		}
+
+		public void GetUpdatedProcesses(out ICollection<IProcessInfo> addedProcesses, out ICollection<IProcessInfo> updatedProcesses, out ICollection<IProcessInfo> removedProcesses)
+		{
+			addedProcesses = new List<IProcessInfo>(16);
+			updatedProcesses = new List<IProcessInfo>(16);
+			removedProcesses = new List<IProcessInfo>(16);
+
+			IList<IntPtr> knownProcesses = new List<IntPtr>(this._processCache.Keys);
+			foreach (Process process in Process.GetProcesses())
+			{
+				string processName = process.ProcessName;
+
+				if (!this.IsMonitoredProcess(processName))
+				{
+					continue;
+				}
+
+				IntPtr mainWindowHandle = process.MainWindowHandle;
+				if (mainWindowHandle == IntPtr.Zero)
+				{
+					continue; // No need to monitor non-visual processes
+				}
+
+				string mainWindowTitle = process.MainWindowTitle;
+				this._processCache.TryGetValue(mainWindowHandle, out string cachedTitle);
+
+				if (cachedTitle == null)
+				{
+					// This is a new process in the list
+					this._processCache.Add(mainWindowHandle, mainWindowTitle);
+					addedProcesses.Add(new ProcessInfo(mainWindowHandle, mainWindowTitle));
+				}
+				else
+				{
+					// This is an already known process
+					if (cachedTitle != mainWindowTitle)
+					{
+						this._processCache[mainWindowHandle] = mainWindowTitle;
+						updatedProcesses.Add((IProcessInfo)new ProcessInfo(mainWindowHandle, mainWindowTitle));
+					}
+
+					knownProcesses.Remove(mainWindowHandle);
+				}
+			}
+
+			foreach (IntPtr index in knownProcesses)
+			{
+				string title = this._processCache[index];
+				removedProcesses.Add(new ProcessInfo(index, title));
+				this._processCache.Remove(index);
+			}
+		}
+
+		public ICollection<IProcessInfo> GetAllProcesses()
+		{
+			ICollection<IProcessInfo> result = new List<IProcessInfo>(this._processCache.Count);
+
+			// TODO Lock list here just in case
+			foreach (KeyValuePair<IntPtr, string> entry in this._processCache)
+			{
+				result.Add(new ProcessInfo(entry.Key, entry.Value));
+			}
+
+			return result;
+		}
+	}
+}