Autosave map functionality (#995)

Added autosaving of the current map. Autosaving happens in intervals when the map is changed. It will not overwrite the current map, but rather create new files, just like backups. Autosaving interval and number of files can be configured in the "Recovery" tab of the preferences. Autosaving can also be disabled there (not recommended). Autosaves will not have their nodes built for performance reason.

Source/Core/Builder.csproj

@@ -241,6 +241,7 @@
     <Compile Include="Dehacked\DehackedFrame.cs" />
     <Compile Include="Dehacked\DehackedParser.cs" />
     <Compile Include="Dehacked\DehackedThing.cs" />
+    <Compile Include="General\AutoSaver.cs" />
     <Compile Include="General\Hasher.cs" />
     <Compile Include="General\SHA256Hash.cs" />
     <Compile Include="General\ToastManager.cs" />

Source/Core/BuilderMono.csproj

@@ -233,6 +233,7 @@
     <Compile Include="Data\FileImage.cs" />
     <Compile Include="Data\FlatImage.cs" />
     <Compile Include="Data\ImageLoadState.cs" />
+    <Compile Include="General\AutoSaver.cs" />
     <Compile Include="General\Hasher.cs" />
     <Compile Include="General\SHA256Hash.cs" />
     <Compile Include="General\ToastManager.cs" />

Source/Core/Config/ProgramConfiguration.cs

@@ -160,6 +160,11 @@ namespace CodeImp.DoomBuilder.Config
 		private int defaultthingtype = 1;
 		private double defaultthingangle;
 		private List<string> defaultthingflags;
+
+		// Autosave
+		private bool autosave;
+		private int autosavecount;
+		private int autosaveinterval;
 		
 		#endregion
 
@@ -298,6 +303,11 @@ namespace CodeImp.DoomBuilder.Config
 		public int DefaultThingType { get { return defaultthingtype; } set { defaultthingtype = value; } }
 		public double DefaultThingAngle { get { return defaultthingangle; } set { defaultthingangle = value; } }
 
+		// Autosave
+		public bool Autosave { get { return autosave; } internal set { autosave = value; } }
+		public int AutosaveCount { get { return autosavecount; } internal set { autosavecount = value; } }
+		public int AutosaveInterval { get { return autosaveinterval; } internal set { autosaveinterval = value; } }
+
 		#endregion
 
 		#region ================== Constructor / Disposer
@@ -455,6 +465,11 @@ namespace CodeImp.DoomBuilder.Config
 					}
 				}
 
+				// Autosave
+				autosave = cfg.ReadSetting("autosave", true);
+				autosavecount = cfg.ReadSetting("autosavecount", 5);
+				autosaveinterval = cfg.ReadSetting("autosaveinterval", 5);
+
 				// Success
 				return true;
 			}
@@ -584,6 +599,11 @@ namespace CodeImp.DoomBuilder.Config
 			for (int i = 0; i < 16; i++)
 				cfg.WriteSetting("colordialogcustomcolors.color" + i, colordialogcustomcolors[i]);
 
+			// Autosave
+			cfg.WriteSetting("autosave", autosave);
+			cfg.WriteSetting("autosavecount", autosavecount);
+			cfg.WriteSetting("autosaveinterval", autosaveinterval);
+
 			// Save settings configuration
 			General.WriteLogLine("Saving program configuration to \"" + filepathname + "\"...");
 			cfg.SaveConfiguration(filepathname);

Source/Core/Editing/EditMode.cs

@@ -264,6 +264,9 @@ namespace CodeImp.DoomBuilder.Editing
 		// This should be called by global actions (i.e. that are not part of an editing mode) when they changed map elements,
 		// so that the mode can react to it (for example by rebuilding a blockmap)
 		public virtual void OnMapElementsChanged() { }
+
+		public virtual bool OnAutoSaveBegin() { return attributes.Volatile ? false : true; } // Called before autosave is done. Returns false if autosave should not be done. By default volatile modes prevent autosave
+		public virtual void OnAutoSaveEnd() { }
 		
 		#endregion
 	}

Source/Core/General/AutoSaver.cs

@@ -0,0 +1,120 @@
+#region ================== Copyright (c) 2023 Boris Iwanski
+
+/*
+ * 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 3 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/>.
+ */
+
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace CodeImp.DoomBuilder
+{
+	internal enum AutosaveResult
+	{
+		Success,
+		Error,
+		NoFileName
+	}
+
+	internal class AutoSaver
+	{
+		private static long lasttime;
+		private static System.Windows.Forms.Timer timer;
+
+		/// <summary>
+		/// Initialized and starts the autosave timer.
+		/// </summary>
+		internal void InitializeTimer()
+		{
+			if(timer != null)
+			{
+				timer.Tick -= TryAutosave;
+				timer.Dispose();
+				timer = null;
+			}
+
+			if (General.Settings.Autosave)
+			{
+				lasttime = Clock.CurrentTime;
+				timer = new System.Windows.Forms.Timer() { Interval = 1000 };
+				timer.Tick += TryAutosave;
+				timer.Enabled = true;
+			}
+		}
+
+		/// <summary>
+		/// Stops the autosave timer.
+		/// </summary>
+		internal void StopTimer()
+		{
+			if (timer != null) timer.Enabled = false;
+		}
+
+		/// <summary>
+		/// Resets the autosave timer to the current time.
+		/// </summary>
+		internal void ResetTimer()
+		{
+			lasttime = Clock.CurrentTime;
+		}
+
+		/// <summary>
+		/// Makes the autosave timer aware of a clock reset, so that the interval until the next autosave is unaffected.
+		/// </summary>
+		internal void BeforeClockReset()
+		{
+			lasttime = -(Clock.CurrentTime - lasttime);
+		}
+
+		/// <summary>
+		/// Tries to perform the autosave.
+		/// </summary>
+		/// <param name="sender">The sender</param>
+		/// <param name="args">The event arguments</param>
+		private static void TryAutosave(object sender, EventArgs args)
+		{
+			if (Clock.CurrentTime > lasttime + General.Settings.AutosaveInterval * 60 * 1000 && General.Map != null && General.Map.Map != null && General.Map.Map.IsSafeToAccess && General.Map.IsChanged)
+			{
+				// Check if the current editing mode prevents autosaving. If it does return without setting the time,
+				// so that autosaving will be retried ASAP
+				if (!General.Editing.Mode.OnAutoSaveBegin())
+					return;
+
+				lasttime = Clock.CurrentTime;
+
+				long start = Clock.CurrentTime;
+				AutosaveResult success = General.Map.AutoSave();
+				long duration = Clock.CurrentTime - start;
+
+				// Show a toast appropriate for the result of the autosave
+				if (success == AutosaveResult.Success)
+					General.ToastManager.ShowToast("autosave", ToastType.INFO, "Autosave", $"Autosave completed successfully in {duration} ms.");
+				else if (success == AutosaveResult.Error)
+					General.ToastManager.ShowToast("autosave", ToastType.ERROR, "Autosave", "Autosave failed.");
+				else if (success == AutosaveResult.NoFileName)
+					General.ToastManager.ShowToast("autosave", ToastType.WARNING, "Autosave", "Could not autosave because this is a new WAD that wasn't saved yet.");
+			}
+		}
+	}
+}

Source/Core/General/General.cs

@@ -239,6 +239,9 @@ namespace CodeImp.DoomBuilder
 		// Toasts
 		private static ToastManager toastmanager;
 
+		// Autosaving
+		private static AutoSaver autosaver;
+
 		#endregion
 
 		#region ================== Properties
@@ -284,6 +287,7 @@ namespace CodeImp.DoomBuilder
 		public static ErrorLogger ErrorLogger { get { return errorlogger; } }
 		public static string CommitHash { get { return commithash; } } //mxd
 		public static ToastManager ToastManager { get => toastmanager; }
+		internal static AutoSaver AutoSaver { get => autosaver; }
 
 		#endregion
 
@@ -808,6 +812,9 @@ namespace CodeImp.DoomBuilder
 				if(General.Settings.CheckForUpdates) UpdateChecker.PerformCheck(false);
 #endif
 
+				// Prepare autosaving
+				autosaver = new AutoSaver();
+
 				// Run application from the main window
 				Application.Run(mainwindow);
 			}
@@ -821,6 +828,7 @@ namespace CodeImp.DoomBuilder
 		private static void RegisterToasts()
 		{
 			toastmanager.RegisterToast("resourcewarningsanderrors", "Resource warnings and errors", "When there are errors or warning while (re)loading the resources");
+			toastmanager.RegisterToast("autosave", "Autosave", "Notifications related to autosaving");
 		}
 
 		// This parses the command line arguments
@@ -1160,7 +1168,7 @@ namespace CodeImp.DoomBuilder
 
 					//mxd. Also reset the clock...
 					MainWindow.ResetClock();
-					
+
 					Cursor.Current = Cursors.Default;
 				}
 			}

Source/Core/General/MapManager.cs

@@ -177,6 +177,9 @@ namespace CodeImp.DoomBuilder
 				// Let the plugins know
 				General.Plugins.OnMapCloseBegin();
 
+				// Stop autosaving
+				General.AutoSaver.StopTimer();
+
 				// Stop processing
 				General.MainWindow.StopProcessing();
 
@@ -343,6 +346,9 @@ namespace CodeImp.DoomBuilder
 			renderer2d.SetViewMode((ViewMode)General.Settings.DefaultViewMode);
 			General.Settings.SetDefaultThingFlags(config.DefaultThingFlags);
 
+			// Autosaver
+			General.AutoSaver.InitializeTimer();
+
 			// Success
 			this.changed = false;
 			this.maploading = false; //mxd
@@ -462,6 +468,9 @@ namespace CodeImp.DoomBuilder
 			// Center map in screen
 			//if(General.Editing.Mode is ClassicMode) (General.Editing.Mode as ClassicMode).CenterInScreen();
 
+			// Autosaver
+			General.AutoSaver.InitializeTimer();
+
 			// Success
 			this.changed = maprestored; //mxd
 			this.maploading = false; //mxd
@@ -575,6 +584,9 @@ namespace CodeImp.DoomBuilder
 				}
 			}
 
+			// Autosaver
+			General.AutoSaver.InitializeTimer();
+
 			// Success
 			this.changed = maprestored;
 			this.maploading = false;
@@ -665,6 +677,26 @@ namespace CodeImp.DoomBuilder
 			return result;
 		}
 
+		/// <summary>
+		/// Autosaves the map.
+		/// </summary>
+		/// <returns>The result of the autosave</returns>
+		internal AutosaveResult AutoSave()
+		{
+			// If the map doesn't exist on a medium we can't make autosaves
+			if (string.IsNullOrWhiteSpace(filepathname))
+				return AutosaveResult.NoFileName;
+
+			// Generat the file name. This is the current file name, a dot, and the map slot, for example
+			// cacowardwinner.wad.MAP01
+			// the SaveMap method will add an ".autosaveX" due to the save purpose being Autosave
+			string autosavefilename = filepathname + "." + options.CurrentName;
+			General.Plugins.OnMapSaveBegin(SavePurpose.Autosave);
+			bool result = SaveMap(autosavefilename, SavePurpose.Autosave);
+			General.Plugins.OnMapSaveEnd(SavePurpose.Autosave);
+			return result ? AutosaveResult.Success : AutosaveResult.Error;
+		}
+
 		/// <summary>
 		/// This writes the map structures to the temporary file.
 		/// </summary>
@@ -755,6 +787,10 @@ namespace CodeImp.DoomBuilder
 		// Initializes for an existing map
 		internal bool SaveMap(string newfilepathname, SavePurpose purpose) 
 		{
+			// Add the autosave suffix. As all existing autosave will be shifted up this is static
+			if (purpose == SavePurpose.Autosave)
+				newfilepathname += ".autosave1";
+
 			string settingsfile;
 			WAD targetwad = null;
 			bool includenodes;
@@ -805,14 +841,22 @@ namespace CodeImp.DoomBuilder
 				// Write the current map structures to the temp file
 				if(!WriteMapToTempFile()) return false;
 
-				// Get the corresponding nodebuilder
+				// Only build nodes when not autosaving
-				string nodebuildername = (purpose == SavePurpose.Testing) ? configinfo.NodebuilderTest : configinfo.NodebuilderSave;
+				if (purpose != SavePurpose.Autosave)
+				{
+					// Get the corresponding nodebuilder
+					string nodebuildername = (purpose == SavePurpose.Testing) ? configinfo.NodebuilderTest : configinfo.NodebuilderSave;
 
-				// Build the nodes
+					// Build the nodes
-				StatusInfo oldstatus = General.MainWindow.Status;
+					StatusInfo oldstatus = General.MainWindow.Status;
-				General.MainWindow.DisplayStatus(StatusType.Busy, "Building map nodes...");
+					General.MainWindow.DisplayStatus(StatusType.Busy, "Building map nodes...");
-				includenodes = (!string.IsNullOrEmpty(nodebuildername) && BuildNodes(nodebuildername, true));
+					includenodes = (!string.IsNullOrEmpty(nodebuildername) && BuildNodes(nodebuildername, true));
-				General.MainWindow.DisplayStatus(oldstatus);
+					General.MainWindow.DisplayStatus(oldstatus);
+				}
+				else
+				{
+					includenodes = false;
+				}
 
 				//mxd. Compress temp file...
 				tempwadreader.WadFile.Compress();
@@ -928,16 +972,34 @@ namespace CodeImp.DoomBuilder
 						}
 					}
 
-					// Backup existing file, if any
+					if (purpose == SavePurpose.Autosave)
-					if(File.Exists(newfilepathname + ".backup3")) File.Delete(newfilepathname + ".backup3");
+					{
-					if(File.Exists(newfilepathname + ".backup2")) File.Move(newfilepathname + ".backup2", newfilepathname + ".backup3");
+						string autosavefilepathname = Path.Combine(Path.GetDirectoryName(newfilepathname), Path.GetFileNameWithoutExtension(newfilepathname));
-					if(File.Exists(newfilepathname + ".backup1")) File.Move(newfilepathname + ".backup1", newfilepathname + ".backup2");
+
-					File.Copy(newfilepathname, newfilepathname + ".backup1");
+						// Delete the last autosave if it exists
+						if (File.Exists($"{autosavefilepathname}.autosave{General.Settings.AutosaveCount}"))
+							File.Delete($"{autosavefilepathname}.autosave{General.Settings.AutosaveCount}");
+
+						// Move all other autosaves up by one
+						for (int i = General.Settings.AutosaveCount-1; i > 0; i--)
+						{
+							if (File.Exists($"{autosavefilepathname}.autosave{i}"))
+								File.Move($"{autosavefilepathname}.autosave{i}", $"{autosavefilepathname}.autosave{i + 1}");
+						}
+					}
+					else
+					{
+						// Backup existing file, if any
+						if (File.Exists(newfilepathname + ".backup3")) File.Delete(newfilepathname + ".backup3");
+						if (File.Exists(newfilepathname + ".backup2")) File.Move(newfilepathname + ".backup2", newfilepathname + ".backup3");
+						if (File.Exists(newfilepathname + ".backup1")) File.Move(newfilepathname + ".backup1", newfilepathname + ".backup2");
+						File.Copy(newfilepathname, newfilepathname + ".backup1");
+					}
 				}
 
 				// Except when saving INTO another file,
 				// kill the target file if it is different from source file
-				if((purpose != SavePurpose.IntoFile) && (newfilepathname != filepathname)) 
+				if ((purpose != SavePurpose.IntoFile) && (newfilepathname != filepathname))
 				{
 					// Kill target file
 					if(File.Exists(newfilepathname)) File.Delete(newfilepathname);
@@ -1043,8 +1105,8 @@ namespace CodeImp.DoomBuilder
 			// Resume data resources
 			data.Resume();
 
-			// Not saved for testing purpose?
+			// Not saved for testing or autosave purpose?
-			if(purpose != SavePurpose.Testing) 
+			if(purpose != SavePurpose.Testing && purpose != SavePurpose.Autosave) 
 			{
 				// Saved in a different file?
 				if(newfilepathname != filepathname) 
@@ -1069,6 +1131,9 @@ namespace CodeImp.DoomBuilder
 					General.ErrorLogger.Add(ErrorType.Warning, "Could not write the map settings configuration file. " + e.GetType().Name + ": " + e.Message);
 				}
 
+				// Autosaver
+				General.AutoSaver.InitializeTimer();
+
 				// Changes saved
 				changed = false;
 				scriptschanged = false;

Source/Core/General/SavePurpose.cs

@@ -25,7 +25,8 @@ namespace CodeImp.DoomBuilder
 		Normal = 0,
 		AsNewFile = 1,
 		IntoFile = 2,
-		Testing = 3
+		Testing = 3,
+		Autosave = 4
 	}
 }
 

Source/Core/Windows/MainForm.cs

@@ -3616,6 +3616,9 @@ namespace CodeImp.DoomBuilder.Windows
 		[BeginAction("preferences")]
 		internal void ShowPreferences()
 		{
+			// Remember the old autostave state, so that we can enable/disable it
+			bool oldautosavestate = General.Settings.Autosave;
+
 			// Show preferences dialog
 			PreferencesForm prefform = new PreferencesForm();
 			if(prefform.ShowDialog(this) == DialogResult.OK)
@@ -3638,6 +3641,15 @@ namespace CodeImp.DoomBuilder.Windows
 					General.Map.Graphics.SetupSettings();
 					General.Map.UpdateConfiguration();
 					if(prefform.ReloadResources) General.Actions.InvokeAction("builder_reloadresources");
+
+					// Autosave stats was changed, so we have to enable or disable it
+					if(oldautosavestate != General.Settings.Autosave)
+					{
+						if (General.Settings.Autosave)
+							General.AutoSaver.InitializeTimer();
+						else
+							General.AutoSaver.StopTimer();
+					}
 				}
 				
 				// Redraw display
@@ -4646,6 +4658,9 @@ namespace CodeImp.DoomBuilder.Windows
 		//mxd
 		internal void ResetClock()
 		{
+			// Let the autosaver know that the clock is about to be reset
+			General.AutoSaver.BeforeClockReset();
+
 			Clock.Reset();
 			lastupdatetime = 0;
 			

Source/Core/Windows/PreferencesForm.Designer.cs

@@ -215,6 +215,18 @@ namespace CodeImp.DoomBuilder.Windows
 			this.tabpasting = new System.Windows.Forms.TabPage();
 			this.label16 = new System.Windows.Forms.Label();
 			this.pasteoptions = new CodeImp.DoomBuilder.Controls.PasteOptionsControl();
+			this.tabrecovery = new System.Windows.Forms.TabPage();
+			this.autosavegroupbox = new System.Windows.Forms.GroupBox();
+			this.autosavedisabledwarning = new System.Windows.Forms.Panel();
+			this.label34 = new System.Windows.Forms.Label();
+			this.pictureBox1 = new System.Windows.Forms.PictureBox();
+			this.autosavecountlabel = new System.Windows.Forms.Label();
+			this.autosavecount = new CodeImp.DoomBuilder.Controls.TransparentTrackBar();
+			this.label21 = new System.Windows.Forms.Label();
+			this.autosaveintervallabel = new System.Windows.Forms.Label();
+			this.autosaveinterval = new CodeImp.DoomBuilder.Controls.TransparentTrackBar();
+			this.label20 = new System.Windows.Forms.Label();
+			this.autosave = new System.Windows.Forms.CheckBox();
 			this.tabtoasts = new System.Windows.Forms.TabPage();
 			this.groupBox10 = new System.Windows.Forms.GroupBox();
 			this.lvToastActions = new System.Windows.Forms.ListView();
@@ -273,6 +285,12 @@ namespace CodeImp.DoomBuilder.Windows
 			this.groupBox6.SuspendLayout();
 			this.previewgroup.SuspendLayout();
 			this.tabpasting.SuspendLayout();
+			this.tabrecovery.SuspendLayout();
+			this.autosavegroupbox.SuspendLayout();
+			this.autosavedisabledwarning.SuspendLayout();
+			((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).BeginInit();
+			((System.ComponentModel.ISupportInitialize)(this.autosavecount)).BeginInit();
+			((System.ComponentModel.ISupportInitialize)(this.autosaveinterval)).BeginInit();
 			this.tabtoasts.SuspendLayout();
 			this.groupBox10.SuspendLayout();
 			this.gbToastPosition.SuspendLayout();
@@ -809,6 +827,7 @@ namespace CodeImp.DoomBuilder.Windows
 			this.tabs.Controls.Add(this.tabcolors);
 			this.tabs.Controls.Add(this.tabscripteditor);
 			this.tabs.Controls.Add(this.tabpasting);
+			this.tabs.Controls.Add(this.tabrecovery);
 			this.tabs.Controls.Add(this.tabtoasts);
 			this.tabs.Font = new System.Drawing.Font("Microsoft Sans Serif", 8.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
 			this.tabs.Location = new System.Drawing.Point(11, 13);
@@ -2448,6 +2467,139 @@ namespace CodeImp.DoomBuilder.Windows
 			this.pasteoptions.Size = new System.Drawing.Size(666, 427);
 			this.pasteoptions.TabIndex = 0;
 			// 
+			// tabrecovery
+			// 
+			this.tabrecovery.Controls.Add(this.autosavegroupbox);
+			this.tabrecovery.Location = new System.Drawing.Point(4, 22);
+			this.tabrecovery.Name = "tabrecovery";
+			this.tabrecovery.Size = new System.Drawing.Size(680, 526);
+			this.tabrecovery.TabIndex = 6;
+			this.tabrecovery.Text = "Recovery";
+			this.tabrecovery.UseVisualStyleBackColor = true;
+			// 
+			// autosavegroupbox
+			// 
+			this.autosavegroupbox.Controls.Add(this.autosavedisabledwarning);
+			this.autosavegroupbox.Controls.Add(this.autosavecountlabel);
+			this.autosavegroupbox.Controls.Add(this.autosavecount);
+			this.autosavegroupbox.Controls.Add(this.label21);
+			this.autosavegroupbox.Controls.Add(this.autosaveintervallabel);
+			this.autosavegroupbox.Controls.Add(this.autosaveinterval);
+			this.autosavegroupbox.Controls.Add(this.label20);
+			this.autosavegroupbox.Controls.Add(this.autosave);
+			this.autosavegroupbox.Font = new System.Drawing.Font("Microsoft Sans Serif", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
+			this.autosavegroupbox.Location = new System.Drawing.Point(8, 8);
+			this.autosavegroupbox.Name = "autosavegroupbox";
+			this.autosavegroupbox.Size = new System.Drawing.Size(666, 147);
+			this.autosavegroupbox.TabIndex = 0;
+			this.autosavegroupbox.TabStop = false;
+			this.autosavegroupbox.Text = "Autosave";
+			// 
+			// autosavedisabledwarning
+			// 
+			this.autosavedisabledwarning.BackColor = System.Drawing.SystemColors.Info;
+			this.autosavedisabledwarning.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
+			this.autosavedisabledwarning.Controls.Add(this.label34);
+			this.autosavedisabledwarning.Controls.Add(this.pictureBox1);
+			this.autosavedisabledwarning.ForeColor = System.Drawing.SystemColors.InfoText;
+			this.autosavedisabledwarning.Location = new System.Drawing.Point(420, 12);
+			this.autosavedisabledwarning.Name = "autosavedisabledwarning";
+			this.autosavedisabledwarning.Size = new System.Drawing.Size(240, 24);
+			this.autosavedisabledwarning.TabIndex = 7;
+			// 
+			// label34
+			// 
+			this.label34.AutoSize = true;
+			this.label34.Location = new System.Drawing.Point(25, 4);
+			this.label34.Name = "label34";
+			this.label34.Size = new System.Drawing.Size(214, 13);
+			this.label34.TabIndex = 1;
+			this.label34.Text = "It is not recommended to disable autosaves!";
+			// 
+			// pictureBox1
+			// 
+			this.pictureBox1.Image = global::CodeImp.DoomBuilder.Properties.Resources.Warning;
+			this.pictureBox1.Location = new System.Drawing.Point(3, 3);
+			this.pictureBox1.Name = "pictureBox1";
+			this.pictureBox1.Size = new System.Drawing.Size(16, 16);
+			this.pictureBox1.TabIndex = 0;
+			this.pictureBox1.TabStop = false;
+			// 
+			// autosavecountlabel
+			// 
+			this.autosavecountlabel.AutoSize = true;
+			this.autosavecountlabel.Location = new System.Drawing.Point(285, 104);
+			this.autosavecountlabel.Name = "autosavecountlabel";
+			this.autosavecountlabel.Size = new System.Drawing.Size(13, 13);
+			this.autosavecountlabel.TabIndex = 6;
+			this.autosavecountlabel.Text = "5";
+			// 
+			// autosavecount
+			// 
+			this.autosavecount.BackColor = System.Drawing.Color.Transparent;
+			this.autosavecount.Location = new System.Drawing.Point(125, 92);
+			this.autosavecount.Maximum = 50;
+			this.autosavecount.Minimum = 1;
+			this.autosavecount.Name = "autosavecount";
+			this.autosavecount.Size = new System.Drawing.Size(154, 45);
+			this.autosavecount.TabIndex = 5;
+			this.autosavecount.TickFrequency = 5;
+			this.autosavecount.TickStyle = System.Windows.Forms.TickStyle.TopLeft;
+			this.autosavecount.Value = 1;
+			this.autosavecount.ValueChanged += new System.EventHandler(this.autosavecount_ValueChanged);
+			// 
+			// label21
+			// 
+			this.label21.AutoSize = true;
+			this.label21.Location = new System.Drawing.Point(8, 104);
+			this.label21.Name = "label21";
+			this.label21.Size = new System.Drawing.Size(111, 13);
+			this.label21.TabIndex = 4;
+			this.label21.Text = "Number of autosaves:";
+			// 
+			// autosaveintervallabel
+			// 
+			this.autosaveintervallabel.AutoSize = true;
+			this.autosaveintervallabel.Location = new System.Drawing.Point(285, 53);
+			this.autosaveintervallabel.Name = "autosaveintervallabel";
+			this.autosaveintervallabel.Size = new System.Drawing.Size(52, 13);
+			this.autosaveintervallabel.TabIndex = 3;
+			this.autosaveintervallabel.Text = "5 minutes";
+			// 
+			// autosaveinterval
+			// 
+			this.autosaveinterval.BackColor = System.Drawing.Color.Transparent;
+			this.autosaveinterval.Location = new System.Drawing.Point(125, 41);
+			this.autosaveinterval.Maximum = 60;
+			this.autosaveinterval.Minimum = 1;
+			this.autosaveinterval.Name = "autosaveinterval";
+			this.autosaveinterval.Size = new System.Drawing.Size(154, 45);
+			this.autosaveinterval.TabIndex = 2;
+			this.autosaveinterval.TickFrequency = 5;
+			this.autosaveinterval.TickStyle = System.Windows.Forms.TickStyle.TopLeft;
+			this.autosaveinterval.Value = 1;
+			this.autosaveinterval.ValueChanged += new System.EventHandler(this.autosaveinterval_ValueChanged);
+			// 
+			// label20
+			// 
+			this.label20.AutoSize = true;
+			this.label20.Location = new System.Drawing.Point(27, 53);
+			this.label20.Name = "label20";
+			this.label20.Size = new System.Drawing.Size(92, 13);
+			this.label20.TabIndex = 1;
+			this.label20.Text = "Autosave interval:";
+			// 
+			// autosave
+			// 
+			this.autosave.AutoSize = true;
+			this.autosave.Location = new System.Drawing.Point(8, 19);
+			this.autosave.Name = "autosave";
+			this.autosave.Size = new System.Drawing.Size(107, 17);
+			this.autosave.TabIndex = 0;
+			this.autosave.Text = "Enable Autosave";
+			this.autosave.UseVisualStyleBackColor = true;
+			this.autosave.CheckedChanged += new System.EventHandler(this.autosave_CheckedChanged);
+			// 
 			// tabtoasts
 			// 
 			this.tabtoasts.Controls.Add(this.groupBox10);
@@ -2675,6 +2827,14 @@ namespace CodeImp.DoomBuilder.Windows
 			this.groupBox6.PerformLayout();
 			this.previewgroup.ResumeLayout(false);
 			this.tabpasting.ResumeLayout(false);
+			this.tabrecovery.ResumeLayout(false);
+			this.autosavegroupbox.ResumeLayout(false);
+			this.autosavegroupbox.PerformLayout();
+			this.autosavedisabledwarning.ResumeLayout(false);
+			this.autosavedisabledwarning.PerformLayout();
+			((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).EndInit();
+			((System.ComponentModel.ISupportInitialize)(this.autosavecount)).EndInit();
+			((System.ComponentModel.ISupportInitialize)(this.autosaveinterval)).EndInit();
 			this.tabtoasts.ResumeLayout(false);
 			this.tabtoasts.PerformLayout();
 			this.groupBox10.ResumeLayout(false);
@@ -2877,5 +3037,17 @@ namespace CodeImp.DoomBuilder.Windows
 		private System.Windows.Forms.ColumnHeader description;
 		private System.Windows.Forms.CheckBox cbParallelizedVertexPlotting;
 		private System.Windows.Forms.CheckBox cbParallelizedLinedefPlotting;
+		private System.Windows.Forms.TabPage tabrecovery;
+		private System.Windows.Forms.GroupBox autosavegroupbox;
+		private Controls.TransparentTrackBar autosaveinterval;
+		private System.Windows.Forms.Label label20;
+		private System.Windows.Forms.CheckBox autosave;
+		private System.Windows.Forms.Label autosaveintervallabel;
+		private System.Windows.Forms.Label autosavecountlabel;
+		private Controls.TransparentTrackBar autosavecount;
+		private System.Windows.Forms.Label label21;
+		private System.Windows.Forms.Panel autosavedisabledwarning;
+		private System.Windows.Forms.Label label34;
+		private System.Windows.Forms.PictureBox pictureBox1;
 	}
 }

Source/Core/Windows/PreferencesForm.cs

@@ -271,6 +271,11 @@ namespace CodeImp.DoomBuilder.Windows
 			// Paste options
 			pasteoptions.Setup(General.Settings.PasteOptions.Copy());
 
+			// Recovery
+			autosave.Checked = General.Settings.Autosave;
+			autosavecount.Value = General.Settings.AutosaveCount;
+			autosaveinterval.Value = General.Settings.AutosaveInterval;
+
 			// Toasts
 			cbToastsEnabled.Checked = General.ToastManager.Enabled;
 			tbToastDuration.Text = (General.ToastManager.Duration / 1000).ToString();
@@ -452,6 +457,11 @@ namespace CodeImp.DoomBuilder.Windows
 			// Paste options
 			General.Settings.PasteOptions = pasteoptions.GetOptions();
 
+			// Recovery
+			General.Settings.Autosave = autosave.Checked;
+			General.Settings.AutosaveCount = autosavecount.Value;
+			General.Settings.AutosaveInterval = autosaveinterval.Value;
+
 			// Toasts
 			General.ToastManager.Enabled = cbToastsEnabled.Checked;
 			General.ToastManager.Anchor = (ToastAnchor)int.Parse((string)gbToastPosition.Controls.OfType<RadioButton>().FirstOrDefault(rb => rb.Checked).Tag);
@@ -462,10 +472,9 @@ namespace CodeImp.DoomBuilder.Windows
 				if(lvi.Tag is ToastRegistryEntry tre)
 					General.ToastManager.Registry[tre.Name].Enabled = lvi.Checked;
 			}
-			
+
 			// Let the plugins know we're closing
 			General.Plugins.OnClosePreferences(controller);
-
 			
 			// Close
 			this.DialogResult = DialogResult.OK;
@@ -1301,6 +1310,25 @@ namespace CodeImp.DoomBuilder.Windows
 
 		#endregion
 
+		#region ================== Recovery
+
+		private void autosave_CheckedChanged(object sender, EventArgs e)
+		{
+			// Enable or disable all controls except the enable/disable checkbox in the group box
+			foreach(Control c in autosavegroupbox.Controls)
+			{
+				if (c == autosave || c == autosavedisabledwarning)
+					continue;
+
+				c.Enabled = autosave.Checked;
+			}
+
+			autosavedisabledwarning.Visible = !autosave.Checked;
+
+		}
+
+		#endregion
+
 		#region ================== Toasts
 
 		private void tbToastDuration_WhenTextChanged(object sender, EventArgs e)
@@ -1332,6 +1360,16 @@ namespace CodeImp.DoomBuilder.Windows
 			}
 		}
 
+		private void autosaveinterval_ValueChanged(object sender, EventArgs e)
+		{
+			autosaveintervallabel.Text = $"{autosaveinterval.Value} minute" + (autosaveinterval.Value > 1 ? "s" : "");
+		}
+
+		private void autosavecount_ValueChanged(object sender, EventArgs e)
+		{
+			autosavecountlabel.Text = autosavecount.Value.ToString();
+		}
+
 		#endregion
 
 		#region ================== Screenshots Stuff (mxd)

Source/Plugins/BuilderModes/ClassicModes/LinedefsMode.cs

@@ -74,6 +74,9 @@ namespace CodeImp.DoomBuilder.BuilderModes
 		// Linedefs that will be edited
 		ICollection<Linedef> editlines;
 
+		// Autosave
+		private bool allowautosave;
+
 		#endregion
 
 		#region ================== Properties
@@ -629,6 +632,9 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			General.Map.Map.ConvertSelection(SelectionType.Linedefs);
 			UpdateSelectionInfo(); //mxd
 			SetupSectorLabels(); //mxd
+
+			// By default we allow autosave
+			allowautosave = true;
 		}
 		
 		// Mode disengages
@@ -834,11 +840,16 @@ namespace CodeImp.DoomBuilder.BuilderModes
 				{
 					if(General.Interface.IsActiveWindow)
 					{
+						// Prevent autosave while the editing dialog is shown
+						allowautosave = false;
+
 						// Show line edit dialog
 						General.Interface.OnEditFormValuesChanged += linedefEditForm_OnValuesChanged;
 						DialogResult result = General.Interface.ShowEditLinedefs(editlines);
 						General.Interface.OnEditFormValuesChanged -= linedefEditForm_OnValuesChanged;
 
+						allowautosave = true;
+
 						General.Map.Map.Update();
 						
 						// Update entire display
@@ -1249,6 +1260,11 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			CreateBlockmap();
 		}
 
+		public override bool OnAutoSaveBegin()
+		{
+			return allowautosave;
+		}
+
 		//mxd
 		private void RenderComment(Linedef l)
 		{

Source/Plugins/BuilderModes/ClassicModes/SectorsMode.cs

@@ -87,6 +87,9 @@ namespace CodeImp.DoomBuilder.BuilderModes
 		// Sectors that will be edited
 		private ICollection<Sector> editsectors;
 
+		// Autosave
+		private bool allowautosave;
+
 		#endregion
 
 		#region ================== Properties
@@ -873,6 +876,9 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			UpdateSelectedLabels();
 			UpdateOverlaySurfaces();//mxd
 			UpdateSelectionInfo(); //mxd
+
+			// By default we allow autosave
+			allowautosave = true;
 		}
 
 		// Mode disengages
@@ -1115,11 +1121,16 @@ namespace CodeImp.DoomBuilder.BuilderModes
 				{
 					if(General.Interface.IsActiveWindow)
 					{
+						// Prevent autosave while the editing dialog is shown
+						allowautosave = false;
+
 						//mxd. Show realtime vertex edit dialog
 						General.Interface.OnEditFormValuesChanged += sectorEditForm_OnValuesChanged;
 						DialogResult result = General.Interface.ShowEditSectors(editsectors);
 						General.Interface.OnEditFormValuesChanged -= sectorEditForm_OnValuesChanged;
 
+						allowautosave = true;
+
 						General.Map.Renderer2D.UpdateExtraFloorFlag(); //mxd
 
 						UpdateEffectLabels();
@@ -1620,6 +1631,11 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			base.ToggleHighlight();
 		}
 
+		public override bool OnAutoSaveBegin()
+		{
+			return allowautosave;
+		}
+
 		//mxd
 		private void RenderComment(Sector s)
 		{

Source/Plugins/BuilderModes/ClassicModes/ThingsMode.cs

@@ -79,6 +79,9 @@ namespace CodeImp.DoomBuilder.BuilderModes
 		// Things that will be edited
 		private ICollection<Thing> editthings;
 
+		// Autosave
+		private bool allowautosave;
+
 		#endregion
 
 		#region ================== Properties
@@ -177,6 +180,9 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			UpdateSelectionInfo(); //mxd
 			UpdateHelperObjects(); //mxd
 			SetupSectorLabels(); //mxd
+
+			// By default we allow autosave
+			allowautosave = true;
 		}
 
 		// Mode disengages
@@ -552,11 +558,16 @@ namespace CodeImp.DoomBuilder.BuilderModes
 						// Edit only when preferred
 						if(!thinginserted || BuilderPlug.Me.EditNewThing)
 						{
+							// Prevent autosave while the editing dialog is shown
+							allowautosave = false;
+
 							//mxd. Show realtime thing edit dialog
 							General.Interface.OnEditFormValuesChanged += thingEditForm_OnValuesChanged;
 							DialogResult result = General.Interface.ShowEditThings(editthings);
 							General.Interface.OnEditFormValuesChanged -= thingEditForm_OnValuesChanged;
 
+							allowautosave = true;
+
 							//mxd. Update helper lines
 							UpdateHelperObjects();
 
@@ -828,6 +839,12 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			}
 		}
 
+		public override bool OnAutoSaveBegin()
+		{
+			return allowautosave;
+		}
+
+
 		//mxd. Check if any selected thing is outside of map boundary
 		private static bool CanDrag(ICollection<Thing> dragthings) 
 		{

Source/Plugins/BuilderModes/ClassicModes/VerticesMode.cs

@@ -62,6 +62,9 @@ namespace CodeImp.DoomBuilder.BuilderModes
 		// Vertices that will be edited
 		ICollection<Vertex> editvertices;
 
+		// Autosave
+		private bool allowautosave;
+
 		#endregion
 
 		#region ================== Properties
@@ -127,6 +130,9 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			// Convert geometry selection to vertices only
 			General.Map.Map.ConvertSelection(SelectionType.Vertices);
 			UpdateSelectionInfo(); //mxd
+
+			// By default we allow autosave
+			allowautosave = true;
 		}
 
 		// Mode disengages
@@ -409,11 +415,16 @@ namespace CodeImp.DoomBuilder.BuilderModes
 				{
 					if(General.Interface.IsActiveWindow)
 					{
+						// Prevent autosave while the editing dialog is shown
+						allowautosave = false;
+
 						//mxd. Show realtime vertex edit dialog
 						General.Interface.OnEditFormValuesChanged += vertexEditForm_OnValuesChanged;
 						DialogResult result = General.Interface.ShowEditVertices(editvertices);
 						General.Interface.OnEditFormValuesChanged -= vertexEditForm_OnValuesChanged;
 
+						allowautosave = true;
+
 						// Update entire display
 						UpdateSelectionInfo(); //mxd
 						General.Interface.RedrawDisplay();
@@ -659,6 +670,11 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			}
 		}
 
+		public override bool OnAutoSaveBegin()
+		{
+			return allowautosave;
+		}
+
 		//mxd. Check if any selected vertex is outside of map boundary
 		private static bool CanDrag(ICollection<Vertex> dragvertices)
 		{