diff --git a/lib/imgui_code_editor/imgui_code_editor.cpp b/lib/imgui_code_editor/imgui_code_editor.cpp
index 2f190ad..5533d28 100644
--- a/lib/imgui_code_editor/imgui_code_editor.cpp
+++ b/lib/imgui_code_editor/imgui_code_editor.cpp
@@ -1,5 +1,6 @@
 #include "imgui_code_editor.h"
 #include "../imgui/imgui_internal.h"
+#include <SDL.h>
 #include <algorithm>
 #include <chrono>
 #include <regex>
@@ -113,6 +114,34 @@ static int ImTextAppendUtf8ToStdStr(std::string &buf, CodeEditor::Char chr) {
 	return ret;
 }
 
+static size_t ImTextToLowerCase(std::string &str) {
+	size_t i = 0;
+	while (i < str.length()) {
+		int n = ImTextExpectUtf8Char(str.c_str() + i);
+		if (n == 0)
+			break;
+		else if (n == 1)
+			str[i] = (char)::tolower(str[i]);
+		i += n;
+	}
+
+	return i;
+}
+
+static size_t ImTextToUpperCase(std::string &str) {
+	size_t i = 0;
+	while (i < str.length()) {
+		int n = ImTextExpectUtf8Char(str.c_str() + i);
+		if (n == 0)
+			break;
+		else if (n == 1)
+			str[i] = (char)::toupper(str[i]);
+		i += n;
+	}
+
+	return i;
+}
+
 CodeEditor::LanguageDefinition CodeEditor::LanguageDefinition::Text(void) {
 	static bool inited = false;
 	static LanguageDefinition langDef;
@@ -590,7 +619,9 @@ bool CodeEditor::UndoRecord::Similar(const UndoRecord* o) const {
 void CodeEditor::UndoRecord::Undo(CodeEditor* aEditor) {
 	if (!Content.empty()) {
 		switch (Type) {
-		case UndoType::Add: {
+		case UndoType::Add: // Fall through.
+		case UndoType::ToLowerCase:  // Fall through.
+		case UndoType::ToUpperCase: {
 				aEditor->State = After;
 
 				aEditor->DeleteRange(Start, End);
@@ -759,7 +790,9 @@ void CodeEditor::UndoRecord::Undo(CodeEditor* aEditor) {
 void CodeEditor::UndoRecord::Redo(CodeEditor* aEditor) {
 	if (!Content.empty()) {
 		switch (Type) {
-		case UndoType::Add: {
+		case UndoType::Add: // Fall through.
+		case UndoType::ToLowerCase:  // Fall through.
+		case UndoType::ToUpperCase: {
 				aEditor->State = Before;
 
 				aEditor->DeleteSelection();
@@ -915,6 +948,13 @@ void CodeEditor::UndoRecord::Redo(CodeEditor* aEditor) {
 	aEditor->OnModified();
 }
 
+CodeEditor::Error::Error() {
+}
+
+CodeEditor::Error::Error(const std::string &msg, bool isWarning_, bool withLineNumber_) :
+	message(msg), isWarning(isWarning_), withLineNumber(withLineNumber_) {
+}
+
 CodeEditor::Glyph::Glyph(Char aChar, ImU32 aColorIndex) : Character(aChar), ColorIndex(aColorIndex), MultiLineComment(false) {
 	if (aChar <= 255) {
 		Codepoint = (ImWchar)aChar;
@@ -960,8 +1000,10 @@ CodeEditor::CodeEditor() :
 	UndoIndex(0),
 	SavedIndex(0),
 	Font(nullptr),
+	IndentWithTab(false),
 	TabSize(4),
 	TextStart(7),
+	HeadSize(0),
 	Overwrite(false),
 	ReadOnly(false),
 	ShowLineNumbers(true),
@@ -973,8 +1015,10 @@ CodeEditor::CodeEditor() :
 	ColorRangeMin(0),
 	ColorRangeMax(0),
 	CheckMultilineComments(0),
+	ErrorTipEnabled(true),
 	TooltipEnabled(true),
 	ShowWhiteSpaces(true),
+	SafeColumnIndicatorOffset(0),
 	EditorFocused(false),
 	ProgramPointer(-1)
 {
@@ -1154,8 +1198,6 @@ void CodeEditor::Render(const char* aTitle, const ImVec2 &aSize, bool aBorder) {
 			MoveHome(shift);
 		else if (!ctrl && !alt && IsKeyPressed(GetKeyIndex(ImGuiKey_End)))
 			MoveEnd(shift);
-		else if (!IsReadOnly() && !ctrl && !shift && !alt && IsKeyPressed(GetKeyIndex(ImGuiKey_Backspace)))
-			BackSpace();
 
 		if (!IsReadOnly()) {
 			if (IsKeyPressed(GetKeyIndex(ImGuiKey_Enter)) || OnKeyPressed(ImGuiKey_Enter)) {
@@ -1187,6 +1229,14 @@ void CodeEditor::Render(const char* aTitle, const ImVec2 &aSize, bool aBorder) {
 							BackSpace(); // Unindent single line.
 					}
 				}
+			} else if (!ctrl && !shift && !alt && IsKeyPressed(GetKeyIndex(ImGuiKey_Backspace))) {
+				BackSpace();
+			} else if (ctrl && !alt && IsKeyPressed(SDL_SCANCODE_U)) {
+				if (shift) {
+					ToUpperCase();
+				} else {
+					ToLowerCase();
+				}
 			}
 		}
 
@@ -1205,7 +1255,7 @@ void CodeEditor::Render(const char* aTitle, const ImVec2 &aSize, bool aBorder) {
 						if (IndentWithTab) {
 							EnterCharacter(c);
 						} else {
-							for (int n = 0; n < TabSize; ++n)
+							for (int i = 0; i < TabSize; ++i)
 								EnterCharacter(' ');
 						}
 					} else {
@@ -1235,8 +1285,17 @@ void CodeEditor::Render(const char* aTitle, const ImVec2 &aSize, bool aBorder) {
 	int lineNo = (int)floor(scrollY / CharAdv.y);
 	const int lineMax = std::max(0, std::min((int)CodeLines.size() - 1, lineNo + (int)ceil((scrollY + contentSize.y) / CharAdv.y)));
 	if (!CodeLines.empty()) {
+		if (GetSafeColumnIndicatorOffset() > 0) {
+			const ImVec2 istart(
+				cursorScreenPos.x + CharAdv.x * TextStart + CharAdv.x * GetSafeColumnIndicatorOffset(),
+				cursorScreenPos.y + CharAdv.y * lineNo
+			);
+			const ImVec2 iend(istart.x, istart.y + std::max(CharAdv.y * (lineMax + 1), contentSize.y));
+			drawList->AddLine(istart, iend, Plt[(int)PaletteIndex::CurrentLineEdge]);
+		}
+
 		while (lineNo <= lineMax) {
-			ImVec2 lineStartScreenPos = ImVec2(cursorScreenPos.x, cursorScreenPos.y + lineNo * CharAdv.y);
+			ImVec2 lineStartScreenPos = ImVec2(cursorScreenPos.x, cursorScreenPos.y + CharAdv.y * lineNo);
 			ImVec2 textScreenPos = ImVec2(lineStartScreenPos.x + CharAdv.x * TextStart, lineStartScreenPos.y);
 
 			Line &line = CodeLines[lineNo];
@@ -1258,8 +1317,8 @@ void CodeEditor::Render(const char* aTitle, const ImVec2 &aSize, bool aBorder) {
 				++ssend;
 
 			if (sstart != -1 && ssend != -1 && sstart < ssend) {
-				const ImVec2 vstart(lineStartScreenPos.x + (CharAdv.x) * (sstart + TextStart), lineStartScreenPos.y);
-				const ImVec2 vend(lineStartScreenPos.x + (CharAdv.x) * (ssend + TextStart), lineStartScreenPos.y + CharAdv.y);
+				const ImVec2 vstart(lineStartScreenPos.x + CharAdv.x * (sstart + TextStart), lineStartScreenPos.y);
+				const ImVec2 vend(lineStartScreenPos.x + CharAdv.x * (ssend + TextStart), lineStartScreenPos.y + CharAdv.y);
 				drawList->AddRectFilled(vstart, vend, Plt[(int)PaletteIndex::Selection]);
 			}
 
@@ -1313,20 +1372,35 @@ void CodeEditor::Render(const char* aTitle, const ImVec2 &aSize, bool aBorder) {
 
 			ErrorMarkers::iterator errorIt = Errs.find(lineNo);
 			if (errorIt != Errs.end()) {
+				const int ln = errorIt->first;
+				const Error &err = errorIt->second;
 				const ImVec2 end(lineStartScreenPos.x + contentSize.x + 2.0f * scrollX, lineStartScreenPos.y + CharAdv.y);
-				drawList->AddRectFilled(start, end, Plt[(int)PaletteIndex::ErrorMarker]);
+				if (err.isWarning)
+					drawList->AddRectFilled(start, end, Plt[(int)PaletteIndex::WarningMarker]);
+				else
+					drawList->AddRectFilled(start, end, Plt[(int)PaletteIndex::ErrorMarker]);
 
-				if (IsTooltipEnabled()) {
+				if (IsErrorTipEnabled()) {
 					if (IsMouseHoveringRect(lineStartScreenPos, end)) {
+						PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(8, 8));
 						BeginTooltip();
-						PushStyleColor(ImGuiCol_Text, ImVec4(1.0f, 0.2f, 0.2f, 1.0f));
-						Text("Error at line %d:", errorIt->first);
-						PopStyleColor();
-						Separator();
-						PushStyleColor(ImGuiCol_Text, ImVec4(1.0f, 1.0f, 0.2f, 1.0f));
-						Text("%s", errorIt->second.c_str());
-						PopStyleColor();
+						if (err.withLineNumber) {
+							if (err.isWarning) {
+								Text("Warning at line %d:", ln);
+							} else {
+								Text("Error at line %d:", ln);
+							}
+							Separator();
+							Text("%s", err.message.c_str());
+						} else {
+							if (err.isWarning) {
+								Text("Warning: %s", err.message.c_str());
+							} else {
+								Text("Error: %s", err.message.c_str());
+							}
+						}
 						EndTooltip();
+						PopStyleVar();
 					}
 				}
 			}
@@ -1788,6 +1862,14 @@ bool CodeEditor::IsShortcutsEnabled(ShortcutType aType) const {
 	return !!(ShortcutsEnabled & aType);
 }
 
+void CodeEditor::SetErrorTipEnabled(bool aValue) {
+	ErrorTipEnabled = aValue;
+}
+
+bool CodeEditor::IsErrorTipEnabled(void) const {
+	return ErrorTipEnabled;
+}
+
 void CodeEditor::SetTooltipEnabled(bool aValue) {
 	TooltipEnabled = aValue;
 }
@@ -1804,6 +1886,14 @@ bool CodeEditor::IsShowWhiteSpaces(void) const {
 	return ShowWhiteSpaces;
 }
 
+void CodeEditor::SetSafeColumnIndicatorOffset(int aValue) {
+	SafeColumnIndicatorOffset = aValue;
+}
+
+int CodeEditor::GetSafeColumnIndicatorOffset(void) const {
+	return SafeColumnIndicatorOffset;
+}
+
 bool CodeEditor::IsEditorFocused(void) const {
 	return EditorFocused;
 }
@@ -2392,6 +2482,66 @@ void CodeEditor::Unindent(bool aByKey) {
 	}
 }
 
+void CodeEditor::ToLowerCase(void) {
+	if (!HasSelection())
+		return;
+
+	UndoRecord u;
+	u.Type = UndoType::ToLowerCase;
+	u.Before = State;
+
+	std::string txt = GetSelectionText();
+	u.Overwritten = txt;
+	DeleteSelection();
+
+	ImTextToLowerCase(txt);
+	u.Content = txt;
+	u.Start = GetActualCursorCoordinates();
+
+	InsertText(txt.c_str());
+
+	u.End = GetActualCursorCoordinates();
+	u.After = State;
+	AddUndo(u);
+	State = u.Before;
+
+	OnModified();
+
+	OnChanged(u.Start, u.End, 0);
+
+	InteractiveStart = InteractiveEnd = State.CursorPosition;
+}
+
+void CodeEditor::ToUpperCase(void) {
+	if (!HasSelection())
+		return;
+
+	UndoRecord u;
+	u.Type = UndoType::ToUpperCase;
+	u.Before = State;
+
+	std::string txt = GetSelectionText();
+	u.Overwritten = txt;
+	DeleteSelection();
+
+	ImTextToUpperCase(txt);
+	u.Content = txt;
+	u.Start = GetActualCursorCoordinates();
+
+	InsertText(txt.c_str());
+
+	u.End = GetActualCursorCoordinates();
+	u.After = State;
+	AddUndo(u);
+	State = u.Before;
+
+	OnModified();
+
+	OnChanged(u.Start, u.End, 0);
+
+	InteractiveStart = InteractiveEnd = State.CursorPosition;
+}
+
 void CodeEditor::Comment(void) {
 	if (IsReadOnly())
 		return;
@@ -2656,7 +2806,8 @@ const CodeEditor::Palette &CodeEditor::GetDarkPalette(void) {
 		0xff2c2c2c, // Background.
 		0xffe0e0e0, // Cursor.
 		0x80a06020, // Selection.
-		0x804d00ff, // ErrorMarker.
+		0x804d00ff, // Error marker.
+		0x8005f0fa, // Warning marker.
 		0xe00020f0, // Breakpoint.
 		0xe000f0f0, // Program pointer.
 		0xffaf912b, // Line number.
@@ -2690,7 +2841,8 @@ const CodeEditor::Palette &CodeEditor::GetLightPalette(void) {
 		0xffffffff, // Background.
 		0xff000000, // Cursor.
 		0xffffd6ad, // Selection.
-		0xa00010ff, // ErrorMarker.
+		0xa00010ff, // Error marker.
+		0x8005f0fa, // Warning marker.
 		0xe00020f0, // Breakpoint.
 		0xe000f0f0, // Program pointer.
 		0xffaf912b, // Line number.
@@ -2724,7 +2876,8 @@ const CodeEditor::Palette &CodeEditor::GetRetroBluePalette(void) {
 		0xff753929, // Background.
 		0xff0080ff, // Cursor.
 		0x80ffff00, // Selection.
-		0xa00000ff, // ErrorMarker.
+		0xa00000ff, // Error marker.
+		0x8005f0fa, // Warning marker.
 		0xe00020f0, // Breakpoint.
 		0xe000f0f0, // Program pointer.
 		0xff808000, // Line number.
diff --git a/lib/imgui_code_editor/imgui_code_editor.h b/lib/imgui_code_editor/imgui_code_editor.h
index e33fc75..c018d0f 100644
--- a/lib/imgui_code_editor/imgui_code_editor.h
+++ b/lib/imgui_code_editor/imgui_code_editor.h
@@ -59,6 +59,7 @@ class CodeEditor {
 		Cursor,
 		Selection,
 		ErrorMarker,
+		WarningMarker,
 		Breakpoint,
 		ProgramPointer,
 		LineNumber,
@@ -132,7 +133,15 @@ class CodeEditor {
 	typedef std::unordered_map<std::string, Identifier> Identifiers;
 	typedef std::unordered_set<std::string> Keywords;
 
-	typedef std::map<int, std::string> ErrorMarkers;
+	struct Error {
+		std::string message;
+		bool isWarning = false;
+		bool withLineNumber = false;
+
+		Error();
+		Error(const std::string &msg, bool isWarning_, bool withLineNumber_);
+	};
+	typedef std::map<int, Error> ErrorMarkers;
 	typedef std::unordered_map<int, bool> Breakpoints;
 
 	typedef std::array<ImU32, (size_t)PaletteIndex::Max> Palette;
@@ -274,12 +283,18 @@ class CodeEditor {
 	void DisableShortcut(ShortcutType aType);
 	bool IsShortcutsEnabled(ShortcutType aType) const;
 
+	void SetErrorTipEnabled(bool aValue);
+	bool IsErrorTipEnabled(void) const;
+
 	void SetTooltipEnabled(bool aValue);
 	bool IsTooltipEnabled(void) const;
 
 	void SetShowWhiteSpaces(bool aValue);
 	bool IsShowWhiteSpaces(void) const;
 
+	void SetSafeColumnIndicatorOffset(int aValue);
+	int GetSafeColumnIndicatorOffset(void) const;
+
 	bool IsEditorFocused(void) const;
 
 	void MoveUp(int aAmount = 1, bool aSelect = false);
@@ -312,6 +327,8 @@ class CodeEditor {
 	void Delete(void);
 	void Indent(bool aByKey = true);
 	void Unindent(bool aByKey = true);
+	void ToLowerCase(void);
+	void ToUpperCase(void);
 	void Comment(void);
 	void Uncomment(void);
 	void MoveLineUp(void);
@@ -341,6 +358,8 @@ class CodeEditor {
 		Remove,
 		Indent,
 		Unindent,
+		ToLowerCase,
+		ToUpperCase,
 		Comment,
 		Uncomment,
 		MoveLineUp,
@@ -418,10 +437,10 @@ class CodeEditor {
 	const ImFont* Font;
 	ImVector<ImWchar> InputBuffer;
 	ImVec2 CharAdv;
-	bool IndentWithTab = false;
+	bool IndentWithTab;
 	int TabSize;
 	int TextStart;
-	float HeadSize = 0;
+	float HeadSize;
 	bool Overwrite;
 	bool ReadOnly;
 	bool ShowLineNumbers;
@@ -434,8 +453,10 @@ class CodeEditor {
 	std::string LastSymbol;
 	PaletteIndex LastSymbolPalette;
 	int CheckMultilineComments;
+	bool ErrorTipEnabled;
 	bool TooltipEnabled;
 	bool ShowWhiteSpaces;
+	int SafeColumnIndicatorOffset;
 	ImVec2 CursorScreenPos;
 	bool EditorFocused;
 
diff --git a/src/theme_sketchbook.cpp b/src/theme_sketchbook.cpp
index cfe8e05..d009232 100644
--- a/src/theme_sketchbook.cpp
+++ b/src/theme_sketchbook.cpp
@@ -3,7 +3,7 @@
 **
 ** An itty bitty game engine.
 **
-** Copyright (C) 2020 - 2023 Tony Wang, all rights reserved
+** Copyright (C) 2020 - 2024 Tony Wang, all rights reserved
 **
 ** For the latest info, see https://github.com/paladin-t/bitty/
 */
diff --git a/src/theme_sketchbook.h b/src/theme_sketchbook.h
index 0c7059e..d866b68 100644
--- a/src/theme_sketchbook.h
+++ b/src/theme_sketchbook.h
@@ -3,7 +3,7 @@
 **
 ** An itty bitty game engine.
 **
-** Copyright (C) 2020 - 2023 Tony Wang, all rights reserved
+** Copyright (C) 2020 - 2024 Tony Wang, all rights reserved
 **
 ** For the latest info, see https://github.com/paladin-t/bitty/
 */
diff --git a/src/widgets_sketchbook.cpp b/src/widgets_sketchbook.cpp
index a43b7e7..25a9f6b 100644
--- a/src/widgets_sketchbook.cpp
+++ b/src/widgets_sketchbook.cpp
@@ -3,7 +3,7 @@
 **
 ** An itty bitty game engine.
 **
-** Copyright (C) 2020 - 2023 Tony Wang, all rights reserved
+** Copyright (C) 2020 - 2024 Tony Wang, all rights reserved
 **
 ** For the latest info, see https://github.com/paladin-t/bitty/
 */
@@ -105,6 +105,49 @@ void PreferencesPopupBox::update(void) {
 				{
 					TextUnformatted(_theme->windowPreferences_Editor_TextEditor());
 
+					PushID("#Col");
+					{
+						AlignTextToFramePadding();
+						TextUnformatted(_theme->windowPreferences_Editor_ColumnIndicator());
+
+						SameLine();
+
+						const char* items[] = {
+							_theme->windowPreferences_Editor_None().c_str(),
+							_theme->windowPreferences_Editor_40().c_str(),
+							_theme->windowPreferences_Editor_80().c_str(),
+							_theme->windowPreferences_Editor_100().c_str(),
+							_theme->windowPreferences_Editor_120().c_str()
+						};
+						int pref = (int)_settingsShadow.editorColumnIndicator;
+						SetNextItemWidth(GetContentRegionAvail().x);
+						if (Combo("", &pref, items, BITTY_COUNTOF(items)))
+							_settingsShadow.editorColumnIndicator = (Workspace::Settings::ColumnIndicator)pref;
+					}
+					PopID();
+
+					PushID("#Ind");
+					{
+						AlignTextToFramePadding();
+						TextUnformatted(_theme->windowPreferences_Editor_IndentWith());
+
+						SameLine();
+
+						const char* items[] = {
+							_theme->windowPreferences_Editor_2Spaces().c_str(),
+							_theme->windowPreferences_Editor_4Spaces().c_str(),
+							_theme->windowPreferences_Editor_8Spaces().c_str(),
+							_theme->windowPreferences_Editor_Tab2SpacesWide().c_str(),
+							_theme->windowPreferences_Editor_Tab4SpacesWide().c_str(),
+							_theme->windowPreferences_Editor_Tab8SpacesWide().c_str()
+						};
+						int pref = (int)_settingsShadow.editorIndentRule;
+						SetNextItemWidth(GetContentRegionAvail().x);
+						if (Combo("", &pref, items, BITTY_COUNTOF(items)))
+							_settingsShadow.editorIndentRule = (Workspace::Settings::IndentRules)pref;
+					}
+					PopID();
+
 					Checkbox(_theme->windowPreferences_Editor_ShowWhiteSpaces(), &_settingsShadow.editorShowWhiteSpaces);
 
 					TextUnformatted(_theme->windowPreferences_Editor_Console());
@@ -363,7 +406,7 @@ void AboutPopupBox::update(void) {
 			SameLine();
 			Url("Tony Wang", "https://paladin-t.github.io/");
 			SameLine();
-			TextUnformatted(", 2020 - 2023");
+			TextUnformatted(", 2020 - 2024");
 			NewLine();
 		}
 		Separator();
diff --git a/src/widgets_sketchbook.h b/src/widgets_sketchbook.h
index 9c11ca6..96ec596 100644
--- a/src/widgets_sketchbook.h
+++ b/src/widgets_sketchbook.h
@@ -3,7 +3,7 @@
 **
 ** An itty bitty game engine.
 **
-** Copyright (C) 2020 - 2023 Tony Wang, all rights reserved
+** Copyright (C) 2020 - 2024 Tony Wang, all rights reserved
 **
 ** For the latest info, see https://github.com/paladin-t/bitty/
 */
diff --git a/src/workspace.cpp b/src/workspace.cpp
index 8066b20..6d24db7 100644
--- a/src/workspace.cpp
+++ b/src/workspace.cpp
@@ -3,7 +3,7 @@
 **
 ** An itty bitty game engine.
 **
-** Copyright (C) 2020 - 2023 Tony Wang, all rights reserved
+** Copyright (C) 2020 - 2024 Tony Wang, all rights reserved
 **
 ** For the latest info, see https://github.com/paladin-t/bitty/
 */
@@ -983,6 +983,16 @@ bool Workspace::load(class Window* wnd, class Renderer* rnd, const class Project
 	Jpath::get(doc, settings()->projectLoadLastProjectAtStartup, "project", "load_last_project_at_startup");
 	Jpath::get(doc, settings()->projectAutoBackup, "project", "auto_backup");
 
+	unsigned indentRule = 0;
+	if (Jpath::get(doc, indentRule, "editor", "indent_rule"))
+		settings()->editorIndentRule = (Settings::IndentRules)indentRule;
+	else
+		settings()->editorIndentRule = Settings::TAB_4;
+	unsigned columnIndicator = 0;
+	if (Jpath::get(doc, columnIndicator, "editor", "column_indicator"))
+		settings()->editorColumnIndicator = (Settings::ColumnIndicator)columnIndicator;
+	else
+		settings()->editorColumnIndicator = Settings::COL_80;
 	Jpath::get(doc, settings()->editorShowWhiteSpaces, "editor", "show_white_spaces");
 	Jpath::get(doc, settings()->editorCaseSensitive, "editor", "case_sensitive");
 	Jpath::get(doc, settings()->editorMatchWholeWord, "editor", "match_whole_word");
@@ -1090,6 +1100,8 @@ bool Workspace::save(class Window* wnd, class Renderer*, const class Project*, c
 	Jpath::set(doc, doc, settings()->projectLoadLastProjectAtStartup, "project", "load_last_project_at_startup");
 	Jpath::set(doc, doc, settings()->projectAutoBackup, "project", "auto_backup");
 
+	Jpath::set(doc, doc, (unsigned)settings()->editorIndentRule, "editor", "indent_rule");
+	Jpath::set(doc, doc, (unsigned)settings()->editorColumnIndicator, "editor", "column_indicator");
 	Jpath::set(doc, doc, settings()->editorShowWhiteSpaces, "editor", "show_white_spaces");
 	Jpath::set(doc, doc, settings()->editorCaseSensitive, "editor", "case_sensitive");
 	Jpath::set(doc, doc, settings()->editorMatchWholeWord, "editor", "match_whole_word");
@@ -3190,6 +3202,10 @@ int Workspace::withEditingAsset(const class Project* project, EditorHandler hand
 void Workspace::fillAssetEditorSettings(Editable* editor) const {
 	editor->post(Editable::SET_THEME_STYLE, (Variant::Int)theme()->styleIndex());
 
+	editor->post(Editable::SET_INDENT_RULE, (Variant::Int)settings()->editorIndentRule);
+
+	editor->post(Editable::SET_COLUMN_INDICATOR, (Variant::Int)settings()->editorColumnIndicator);
+
 	editor->post(Editable::SET_SHOW_SPACES, settings()->editorShowWhiteSpaces);
 }
 
diff --git a/src/workspace.h b/src/workspace.h
index c366dc1..35c25a7 100644
--- a/src/workspace.h
+++ b/src/workspace.h
@@ -3,7 +3,7 @@
 **
 ** An itty bitty game engine.
 **
-** Copyright (C) 2020 - 2023 Tony Wang, all rights reserved
+** Copyright (C) 2020 - 2024 Tony Wang, all rights reserved
 **
 ** For the latest info, see https://github.com/paladin-t/bitty/
 */
@@ -160,6 +160,22 @@ class CodeEditor;
 class Workspace : public Executable::Observer, public Dispatchable, public NonCopyable {
 public:
 	struct Settings {
+		enum IndentRules : unsigned {
+			SPACE_2,
+			SPACE_4,
+			SPACE_8,
+			TAB_2,
+			TAB_4,
+			TAB_8
+		};
+		enum ColumnIndicator : unsigned {
+			COL_NONE,
+			COL_40,
+			COL_80,
+			COL_100,
+			COL_120
+		};
+
 		int applicationWindowDisplayIndex = 0;
 		bool applicationWindowFullscreen = false;
 		bool applicationWindowMaximized = false;
@@ -177,6 +193,8 @@ class Workspace : public Executable::Observer, public Dispatchable, public NonCo
 
 		bool assetsVisible = true;
 
+		IndentRules editorIndentRule = TAB_4;
+		ColumnIndicator editorColumnIndicator = COL_80;
 		bool editorShowWhiteSpaces = true;
 		bool editorCaseSensitive = false;
 		bool editorMatchWholeWord = false;
diff --git a/src/workspace_sketchbook.cpp b/src/workspace_sketchbook.cpp
index 25dd383..a8c421e 100644
--- a/src/workspace_sketchbook.cpp
+++ b/src/workspace_sketchbook.cpp
@@ -3,7 +3,7 @@
 **
 ** An itty bitty game engine.
 **
-** Copyright (C) 2020 - 2023 Tony Wang, all rights reserved
+** Copyright (C) 2020 - 2024 Tony Wang, all rights reserved
 **
 ** For the latest info, see https://github.com/paladin-t/bitty/
 */
@@ -66,6 +66,8 @@ WorkspaceSketchbook::SketchbookSettings &WorkspaceSketchbook::SketchbookSettings
 	bannerVisible = other.bannerVisible;
 	assetsVisible = other.assetsVisible;
 
+	editorIndentRule = other.editorIndentRule;
+	editorColumnIndicator = other.editorColumnIndicator;
 	editorShowWhiteSpaces = other.editorShowWhiteSpaces;
 	editorCaseSensitive = other.editorCaseSensitive;
 	editorMatchWholeWord = other.editorMatchWholeWord;
@@ -126,7 +128,9 @@ bool WorkspaceSketchbook::SketchbookSettings::operator != (const SketchbookSetti
 	if (assetsVisible != other.assetsVisible)
 		return true;
 
-	if (editorShowWhiteSpaces != other.editorShowWhiteSpaces ||
+	if (editorIndentRule != other.editorIndentRule ||
+		editorColumnIndicator != other.editorColumnIndicator ||
+		editorShowWhiteSpaces != other.editorShowWhiteSpaces ||
 		editorCaseSensitive != other.editorCaseSensitive ||
 		editorMatchWholeWord != other.editorMatchWholeWord ||
 		editorGlobalSearch != other.editorGlobalSearch
@@ -1395,6 +1399,24 @@ void WorkspaceSketchbook::showPreferences(class Window* wnd, class Renderer*, co
 				_settings.projectAutoBackup = sets.projectAutoBackup;
 			}
 
+			if (sets.editorIndentRule != _settings.editorIndentRule) {
+				prj->foreach(
+					[&] (Asset* &asset, Asset::List::Index) -> void {
+						Editable* editor =  asset->editor();
+						if (editor)
+							editor->post(Editable::SET_INDENT_RULE, (Variant::Int)sets.editorIndentRule);
+					}
+				);
+			}
+			if (sets.editorColumnIndicator != _settings.editorColumnIndicator) {
+				prj->foreach(
+					[&] (Asset* &asset, Asset::List::Index) -> void {
+						Editable* editor =  asset->editor();
+						if (editor)
+							editor->post(Editable::SET_COLUMN_INDICATOR, (Variant::Int)sets.editorColumnIndicator);
+					}
+				);
+			}
 			if (sets.editorShowWhiteSpaces != _settings.editorShowWhiteSpaces) {
 				prj->foreach(
 					[&] (Asset* &asset, Asset::List::Index) -> void {
diff --git a/src/workspace_sketchbook.h b/src/workspace_sketchbook.h
index 3cf14be..9bd9c44 100644
--- a/src/workspace_sketchbook.h
+++ b/src/workspace_sketchbook.h
@@ -3,7 +3,7 @@
 **
 ** An itty bitty game engine.
 **
-** Copyright (C) 2020 - 2023 Tony Wang, all rights reserved
+** Copyright (C) 2020 - 2024 Tony Wang, all rights reserved
 **
 ** For the latest info, see https://github.com/paladin-t/bitty/
 */