Add ScrollUp and ScrollDown commands for viewport scrolling, refine mouse wheel handling in GUI and terminal, and bump version to 1.2.2.

CMakeLists.txt

@@ -4,7 +4,7 @@ project(kte)
 include(GNUInstallDirs)
 
 set(CMAKE_CXX_STANDARD 17)
-set(KTE_VERSION "1.2.1")
+set(KTE_VERSION "1.2.2")
 
 # Default to terminal-only build to avoid SDL/OpenGL dependency by default.
 # Enable with -DBUILD_GUI=ON when SDL2/OpenGL/Freetype are available.
@@ -16,36 +16,36 @@ option(KTE_UNDO_DEBUG "Enable undo instrumentation logs" OFF)
 option(KTE_ENABLE_TREESITTER "Enable optional Tree-sitter highlighter adapter" OFF)
 
 if (CMAKE_HOST_UNIX)
-	message(STATUS "Build system is POSIX.")
+    message(STATUS "Build system is POSIX.")
 else ()
-	message(STATUS "Build system is NOT POSIX.")
+    message(STATUS "Build system is NOT POSIX.")
 endif ()
 
 if (MSVC)
-	add_compile_options("/W4" "$<$<CONFIG:RELEASE>:/O2>")
+    add_compile_options("/W4" "$<$<CONFIG:RELEASE>:/O2>")
 else ()
-	add_compile_options(
-		"-Wall"
-		"-Wextra"
-		"-Werror"
-		"$<$<CONFIG:DEBUG>:-g>"
-		"$<$<CONFIG:RELEASE>:-O2>")
-	if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
-		add_compile_options("-stdlib=libc++")
-	else ()
-		# nothing special for gcc at the moment
-	endif ()
+    add_compile_options(
+            "-Wall"
+            "-Wextra"
+            "-Werror"
+            "$<$<CONFIG:DEBUG>:-g>"
+            "$<$<CONFIG:RELEASE>:-O2>")
+    if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
+        add_compile_options("-stdlib=libc++")
+    else ()
+        # nothing special for gcc at the moment
+    endif ()
 endif ()
 add_compile_definitions(KGE_PLATFORM=${CMAKE_HOST_SYSTEM_NAME})
 add_compile_definitions(KTE_VERSION_STR="v${KTE_VERSION}")
 if (KTE_ENABLE_TREESITTER)
-	add_compile_definitions(KTE_ENABLE_TREESITTER)
+    add_compile_definitions(KTE_ENABLE_TREESITTER)
 endif ()
 
 message(STATUS "Build system: ${CMAKE_HOST_SYSTEM_NAME}")
 
 if (${BUILD_GUI})
-	include(cmake/imgui.cmake)
+    include(cmake/imgui.cmake)
 endif ()
 
 # NCurses for terminal mode
@@ -55,250 +55,250 @@ find_package(Curses REQUIRED)
 include_directories(${CURSES_INCLUDE_DIR})
 
 set(SYNTAX_SOURCES
-	syntax/GoHighlighter.cc
-	syntax/CppHighlighter.cc
-	syntax/JsonHighlighter.cc
-	syntax/ErlangHighlighter.cc
-	syntax/MarkdownHighlighter.cc
-	syntax/TreeSitterHighlighter.cc
-	syntax/LispHighlighter.cc
-	syntax/HighlighterEngine.cc
-	syntax/RustHighlighter.cc
-	syntax/HighlighterRegistry.cc
-	syntax/SqlHighlighter.cc
-	syntax/NullHighlighter.cc
-	syntax/ForthHighlighter.cc
-	syntax/PythonHighlighter.cc
-	syntax/ShellHighlighter.cc
+        syntax/GoHighlighter.cc
+        syntax/CppHighlighter.cc
+        syntax/JsonHighlighter.cc
+        syntax/ErlangHighlighter.cc
+        syntax/MarkdownHighlighter.cc
+        syntax/TreeSitterHighlighter.cc
+        syntax/LispHighlighter.cc
+        syntax/HighlighterEngine.cc
+        syntax/RustHighlighter.cc
+        syntax/HighlighterRegistry.cc
+        syntax/SqlHighlighter.cc
+        syntax/NullHighlighter.cc
+        syntax/ForthHighlighter.cc
+        syntax/PythonHighlighter.cc
+        syntax/ShellHighlighter.cc
 )
 
 if (KTE_ENABLE_TREESITTER)
-	list(APPEND SYNTAX_SOURCES
-		TreeSitterHighlighter.cc)
+    list(APPEND SYNTAX_SOURCES
+            TreeSitterHighlighter.cc)
 endif ()
 
 set(COMMON_SOURCES
-	GapBuffer.cc
-	PieceTable.cc
-	Buffer.cc
-	Editor.cc
-	Command.cc
-	HelpText.cc
-	KKeymap.cc
-	TerminalInputHandler.cc
-	TerminalRenderer.cc
-	TerminalFrontend.cc
-	TestInputHandler.cc
-	TestRenderer.cc
-	TestFrontend.cc
-	UndoNode.cc
-	UndoTree.cc
-	UndoSystem.cc
+        GapBuffer.cc
+        PieceTable.cc
+        Buffer.cc
+        Editor.cc
+        Command.cc
+        HelpText.cc
+        KKeymap.cc
+        TerminalInputHandler.cc
+        TerminalRenderer.cc
+        TerminalFrontend.cc
+        TestInputHandler.cc
+        TestRenderer.cc
+        TestFrontend.cc
+        UndoNode.cc
+        UndoTree.cc
+        UndoSystem.cc
 
-	${SYNTAX_SOURCES}
+        ${SYNTAX_SOURCES}
 )
 
 
 set(SYNTAX_HEADERS
-	syntax/GoHighlighter.h
-	syntax/HighlighterEngine.h
-	syntax/ShellHighlighter.h
-	syntax/MarkdownHighlighter.h
-	syntax/LispHighlighter.h
-	syntax/SqlHighlighter.h
-	syntax/ForthHighlighter.h
-	syntax/JsonHighlighter.h
-	syntax/TreeSitterHighlighter.h
-	syntax/NullHighlighter.h
-	syntax/CppHighlighter.h
-	syntax/ErlangHighlighter.h
-	syntax/LanguageHighlighter.h
-	syntax/RustHighlighter.h
-	syntax/PythonHighlighter.h
+        syntax/GoHighlighter.h
+        syntax/HighlighterEngine.h
+        syntax/ShellHighlighter.h
+        syntax/MarkdownHighlighter.h
+        syntax/LispHighlighter.h
+        syntax/SqlHighlighter.h
+        syntax/ForthHighlighter.h
+        syntax/JsonHighlighter.h
+        syntax/TreeSitterHighlighter.h
+        syntax/NullHighlighter.h
+        syntax/CppHighlighter.h
+        syntax/ErlangHighlighter.h
+        syntax/LanguageHighlighter.h
+        syntax/RustHighlighter.h
+        syntax/PythonHighlighter.h
 )
 
 if (KTE_ENABLE_TREESITTER)
-	list(APPEND THEME_HEADERS
-		TreeSitterHighlighter.h)
+    list(APPEND THEME_HEADERS
+            TreeSitterHighlighter.h)
 endif ()
 
 set(THEME_HEADERS
-	themes/ThemeHelpers.h
-	themes/EInk.h
-	themes/Gruvbox.h
-	themes/Solarized.h
-	themes/Plan9.h
-	themes/Nord.h
+        themes/ThemeHelpers.h
+        themes/EInk.h
+        themes/Gruvbox.h
+        themes/Solarized.h
+        themes/Plan9.h
+        themes/Nord.h
 )
 
 set(COMMON_HEADERS
-	GapBuffer.h
-	PieceTable.h
-	Buffer.h
-	Editor.h
-	AppendBuffer.h
-	Command.h
-	HelpText.h
-	KKeymap.h
-	InputHandler.h
-	TerminalInputHandler.h
-	Renderer.h
-	TerminalRenderer.h
-	Frontend.h
-	TerminalFrontend.h
-	TestInputHandler.h
-	TestRenderer.h
-	TestFrontend.h
-	UndoNode.h
-	UndoTree.h
-	UndoSystem.h
-	Highlight.h
+        GapBuffer.h
+        PieceTable.h
+        Buffer.h
+        Editor.h
+        AppendBuffer.h
+        Command.h
+        HelpText.h
+        KKeymap.h
+        InputHandler.h
+        TerminalInputHandler.h
+        Renderer.h
+        TerminalRenderer.h
+        Frontend.h
+        TerminalFrontend.h
+        TestInputHandler.h
+        TestRenderer.h
+        TestFrontend.h
+        UndoNode.h
+        UndoTree.h
+        UndoSystem.h
+        Highlight.h
 
-	${SYNTAX_HEADERS}
-	${THEME_HEADERS}
+        ${SYNTAX_HEADERS}
+        ${THEME_HEADERS}
 )
 
 # kte (terminal-first) executable
 add_executable(kte
-	main.cc
-	${COMMON_SOURCES}
-	${COMMON_HEADERS}
+        main.cc
+        ${COMMON_SOURCES}
+        ${COMMON_HEADERS}
 )
 
 if (KTE_USE_PIECE_TABLE)
-	target_compile_definitions(kte PRIVATE KTE_USE_PIECE_TABLE=1)
+    target_compile_definitions(kte PRIVATE KTE_USE_PIECE_TABLE=1)
 endif ()
 if (KTE_UNDO_DEBUG)
-	target_compile_definitions(kte PRIVATE KTE_UNDO_DEBUG=1)
+    target_compile_definitions(kte PRIVATE KTE_UNDO_DEBUG=1)
 endif ()
 
 target_link_libraries(kte ${CURSES_LIBRARIES})
 
 if (KTE_ENABLE_TREESITTER)
-	# Users can provide their own tree-sitter include/lib via cache variables
-	set(TREESITTER_INCLUDE_DIR "" CACHE PATH "Path to tree-sitter include directory")
-	set(TREESITTER_LIBRARY "" CACHE FILEPATH "Path to tree-sitter library (.a/.dylib)")
-	if (TREESITTER_INCLUDE_DIR)
-		target_include_directories(kte PRIVATE ${TREESITTER_INCLUDE_DIR})
-	endif ()
-	if (TREESITTER_LIBRARY)
-		target_link_libraries(kte ${TREESITTER_LIBRARY})
-	endif ()
+    # Users can provide their own tree-sitter include/lib via cache variables
+    set(TREESITTER_INCLUDE_DIR "" CACHE PATH "Path to tree-sitter include directory")
+    set(TREESITTER_LIBRARY "" CACHE FILEPATH "Path to tree-sitter library (.a/.dylib)")
+    if (TREESITTER_INCLUDE_DIR)
+        target_include_directories(kte PRIVATE ${TREESITTER_INCLUDE_DIR})
+    endif ()
+    if (TREESITTER_LIBRARY)
+        target_link_libraries(kte ${TREESITTER_LIBRARY})
+    endif ()
 endif ()
 
 install(TARGETS kte
-	RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+        RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
 )
 
 # Man pages
 install(FILES docs/kte.1 DESTINATION ${CMAKE_INSTALL_MANDIR}/man1)
 
 if (BUILD_TESTS)
-	# test_undo executable for testing undo/redo system
-	add_executable(test_undo
-		test_undo.cc
-		${COMMON_SOURCES}
-		${COMMON_HEADERS}
-	)
+    # test_undo executable for testing undo/redo system
+    add_executable(test_undo
+            test_undo.cc
+            ${COMMON_SOURCES}
+            ${COMMON_HEADERS}
+    )
 
-	if (KTE_USE_PIECE_TABLE)
-		target_compile_definitions(test_undo PRIVATE KTE_USE_PIECE_TABLE=1)
-	endif ()
+    if (KTE_USE_PIECE_TABLE)
+        target_compile_definitions(test_undo PRIVATE KTE_USE_PIECE_TABLE=1)
+    endif ()
 
-	if (KTE_UNDO_DEBUG)
-		target_compile_definitions(test_undo PRIVATE KTE_UNDO_DEBUG=1)
-	endif ()
+    if (KTE_UNDO_DEBUG)
+        target_compile_definitions(test_undo PRIVATE KTE_UNDO_DEBUG=1)
+    endif ()
 
 
-	target_link_libraries(test_undo ${CURSES_LIBRARIES})
-	if (KTE_ENABLE_TREESITTER)
-		if (TREESITTER_INCLUDE_DIR)
-			target_include_directories(test_undo PRIVATE ${TREESITTER_INCLUDE_DIR})
-		endif ()
-		if (TREESITTER_LIBRARY)
-			target_link_libraries(test_undo ${TREESITTER_LIBRARY})
-		endif ()
-	endif ()
+    target_link_libraries(test_undo ${CURSES_LIBRARIES})
+    if (KTE_ENABLE_TREESITTER)
+        if (TREESITTER_INCLUDE_DIR)
+            target_include_directories(test_undo PRIVATE ${TREESITTER_INCLUDE_DIR})
+        endif ()
+        if (TREESITTER_LIBRARY)
+            target_link_libraries(test_undo ${TREESITTER_LIBRARY})
+        endif ()
+    endif ()
 endif ()
 
 if (${BUILD_GUI})
-	target_sources(kte PRIVATE
-		Font.h
-		GUIConfig.cc
-		GUIConfig.h
-		GUIRenderer.cc
-		GUIRenderer.h
-		GUIInputHandler.cc
-		GUIInputHandler.h
-		GUIFrontend.cc
-		GUIFrontend.h)
-	target_compile_definitions(kte PRIVATE KTE_BUILD_GUI=1)
-	target_link_libraries(kte imgui)
+    target_sources(kte PRIVATE
+            Font.h
+            GUIConfig.cc
+            GUIConfig.h
+            GUIRenderer.cc
+            GUIRenderer.h
+            GUIInputHandler.cc
+            GUIInputHandler.h
+            GUIFrontend.cc
+            GUIFrontend.h)
+    target_compile_definitions(kte PRIVATE KTE_BUILD_GUI=1)
+    target_link_libraries(kte imgui)
 
-	# kge (GUI-first) executable
-	add_executable(kge
-		main.cc
-		${COMMON_SOURCES}
-		${COMMON_HEADERS}
-		GUIConfig.cc
-		GUIConfig.h
-		GUIRenderer.cc
-		GUIRenderer.h
-		GUIInputHandler.cc
-		GUIInputHandler.h
-		GUIFrontend.cc
-		GUIFrontend.h)
-	target_compile_definitions(kge PRIVATE KTE_BUILD_GUI=1 KTE_DEFAULT_GUI=1 KTE_FONT_SIZE=${KTE_FONT_SIZE})
-	if (KTE_UNDO_DEBUG)
-		target_compile_definitions(kge PRIVATE KTE_UNDO_DEBUG=1)
-	endif ()
-	target_link_libraries(kge ${CURSES_LIBRARIES} imgui)
+    # kge (GUI-first) executable
+    add_executable(kge
+            main.cc
+            ${COMMON_SOURCES}
+            ${COMMON_HEADERS}
+            GUIConfig.cc
+            GUIConfig.h
+            GUIRenderer.cc
+            GUIRenderer.h
+            GUIInputHandler.cc
+            GUIInputHandler.h
+            GUIFrontend.cc
+            GUIFrontend.h)
+    target_compile_definitions(kge PRIVATE KTE_BUILD_GUI=1 KTE_DEFAULT_GUI=1 KTE_FONT_SIZE=${KTE_FONT_SIZE})
+    if (KTE_UNDO_DEBUG)
+        target_compile_definitions(kge PRIVATE KTE_UNDO_DEBUG=1)
+    endif ()
+    target_link_libraries(kge ${CURSES_LIBRARIES} imgui)
 
-	# On macOS, build kge as a proper .app bundle
-	if (APPLE)
-		# Define the icon file
-		set(MACOSX_BUNDLE_ICON_FILE kge.icns)
-		set(kge_ICON "${CMAKE_CURRENT_SOURCE_DIR}/${MACOSX_BUNDLE_ICON_FILE}")
+    # On macOS, build kge as a proper .app bundle
+    if (APPLE)
+        # Define the icon file
+        set(MACOSX_BUNDLE_ICON_FILE kge.icns)
+        set(kge_ICON "${CMAKE_CURRENT_SOURCE_DIR}/${MACOSX_BUNDLE_ICON_FILE}")
 
-		# Add icon to the target sources and mark it as a resource
-		target_sources(kge PRIVATE ${kge_ICON})
-		set_source_files_properties(${kge_ICON} PROPERTIES
-			MACOSX_PACKAGE_LOCATION Resources)
+        # Add icon to the target sources and mark it as a resource
+        target_sources(kge PRIVATE ${kge_ICON})
+        set_source_files_properties(${kge_ICON} PROPERTIES
+                MACOSX_PACKAGE_LOCATION Resources)
 
-		# Configure Info.plist with version and identifiers
-		set(KGE_BUNDLE_ID "dev.wntrmute.kge")
-		configure_file(
-			${CMAKE_CURRENT_LIST_DIR}/cmake/Info.plist.in
-			${CMAKE_CURRENT_BINARY_DIR}/kge-Info.plist
-			@ONLY)
+        # Configure Info.plist with version and identifiers
+        set(KGE_BUNDLE_ID "dev.wntrmute.kge")
+        configure_file(
+                ${CMAKE_CURRENT_LIST_DIR}/cmake/Info.plist.in
+                ${CMAKE_CURRENT_BINARY_DIR}/kge-Info.plist
+                @ONLY)
 
-		set_target_properties(kge PROPERTIES
-			MACOSX_BUNDLE TRUE
-			MACOSX_BUNDLE_GUI_IDENTIFIER ${KGE_BUNDLE_ID}
-			MACOSX_BUNDLE_BUNDLE_NAME "kge"
-			MACOSX_BUNDLE_ICON_FILE ${MACOSX_BUNDLE_ICON_FILE}
-			MACOSX_BUNDLE_INFO_PLIST "${CMAKE_CURRENT_BINARY_DIR}/kge-Info.plist")
+        set_target_properties(kge PROPERTIES
+                MACOSX_BUNDLE TRUE
+                MACOSX_BUNDLE_GUI_IDENTIFIER ${KGE_BUNDLE_ID}
+                MACOSX_BUNDLE_BUNDLE_NAME "kge"
+                MACOSX_BUNDLE_ICON_FILE ${MACOSX_BUNDLE_ICON_FILE}
+                MACOSX_BUNDLE_INFO_PLIST "${CMAKE_CURRENT_BINARY_DIR}/kge-Info.plist")
 
-		add_dependencies(kge kte)
-		add_custom_command(TARGET kge POST_BUILD
-			COMMAND ${CMAKE_COMMAND} -E copy
-			$<TARGET_FILE:kte>
-			$<TARGET_FILE_DIR:kge>/kte
-			COMMENT "Copying kte binary into kge.app bundle")
+        add_dependencies(kge kte)
+        add_custom_command(TARGET kge POST_BUILD
+                COMMAND ${CMAKE_COMMAND} -E copy
+                $<TARGET_FILE:kte>
+                $<TARGET_FILE_DIR:kge>/kte
+                COMMENT "Copying kte binary into kge.app bundle")
 
-		install(TARGETS kge
-			BUNDLE DESTINATION .
-		)
+        install(TARGETS kge
+                BUNDLE DESTINATION .
+        )
 
-		install(TARGETS kte
-			RUNTIME DESTINATION kge.app/Contents/MacOS
-		)
-	else ()
-		install(TARGETS kge
-			RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
-		)
-	endif ()
-	# Install kge man page only when GUI is built
-	install(FILES docs/kge.1 DESTINATION ${CMAKE_INSTALL_MANDIR}/man1)
-	install(FILES kge.png DESTINATION ${CMAKE_INSTALL_PREFIX}/share/icons)
+        install(TARGETS kte
+                RUNTIME DESTINATION kge.app/Contents/MacOS
+        )
+    else ()
+        install(TARGETS kge
+                RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+        )
+    endif ()
+    # Install kge man page only when GUI is built
+    install(FILES docs/kge.1 DESTINATION ${CMAKE_INSTALL_MANDIR}/man1)
+    install(FILES kge.png DESTINATION ${CMAKE_INSTALL_PREFIX}/share/icons)
 endif ()

Command.cc

@@ -3067,6 +3067,74 @@ cmd_page_down(CommandContext &ctx)
 }
 
 
+static bool
+cmd_scroll_up(CommandContext &ctx)
+{
+	Buffer *buf = ctx.editor.CurrentBuffer();
+	if (!buf)
+		return false;
+	ensure_at_least_one_line(*buf);
+	const auto &rows         = buf->Rows();
+	std::size_t content_rows = std::max<std::size_t>(1, ctx.editor.ContentRows());
+	std::size_t rowoffs      = buf->Rowoffs();
+
+	// Scroll up by 3 lines (or count if specified), without moving cursor
+	int scroll_amount = ctx.count > 0 ? ctx.count : 3;
+	if (rowoffs >= static_cast<std::size_t>(scroll_amount))
+		rowoffs -= static_cast<std::size_t>(scroll_amount);
+	else
+		rowoffs = 0;
+
+	buf->SetOffsets(rowoffs, buf->Coloffs());
+
+	// If cursor is now below the visible area, move it to the last visible line
+	std::size_t cury = buf->Cury();
+	if (cury >= rowoffs + content_rows) {
+		std::size_t new_y = rowoffs + content_rows - 1;
+		if (new_y >= rows.size() && !rows.empty())
+			new_y = rows.size() - 1;
+		buf->SetCursor(buf->Curx(), new_y);
+	}
+
+	return true;
+}
+
+
+static bool
+cmd_scroll_down(CommandContext &ctx)
+{
+	Buffer *buf = ctx.editor.CurrentBuffer();
+	if (!buf)
+		return false;
+	ensure_at_least_one_line(*buf);
+	const auto &rows         = buf->Rows();
+	std::size_t content_rows = std::max<std::size_t>(1, ctx.editor.ContentRows());
+	std::size_t rowoffs      = buf->Rowoffs();
+
+	// Scroll down by 3 lines (or count if specified), without moving cursor
+	int scroll_amount = ctx.count > 0 ? ctx.count : 3;
+
+	// Compute maximum top offset
+	std::size_t max_top = 0;
+	if (!rows.empty() && rows.size() > content_rows)
+		max_top = rows.size() - content_rows;
+
+	rowoffs += static_cast<std::size_t>(scroll_amount);
+	if (rowoffs > max_top)
+		rowoffs = max_top;
+
+	buf->SetOffsets(rowoffs, buf->Coloffs());
+
+	// If cursor is now above the visible area, move it to the first visible line
+	std::size_t cury = buf->Cury();
+	if (cury < rowoffs) {
+		buf->SetCursor(buf->Curx(), rowoffs);
+	}
+
+	return true;
+}
+
+
 static inline bool
 is_word_char(unsigned char c)
 {
@@ -3675,6 +3743,8 @@ InstallDefaultCommands()
 	CommandRegistry::Register({CommandId::MoveEnd, "end", "Move to end of line", cmd_move_end});
 	CommandRegistry::Register({CommandId::PageUp, "page-up", "Page up", cmd_page_up});
 	CommandRegistry::Register({CommandId::PageDown, "page-down", "Page down", cmd_page_down});
+	CommandRegistry::Register({CommandId::ScrollUp, "scroll-up", "Scroll viewport up", cmd_scroll_up});
+	CommandRegistry::Register({CommandId::ScrollDown, "scroll-down", "Scroll viewport down", cmd_scroll_down});
 	CommandRegistry::Register({CommandId::WordPrev, "word-prev", "Move to previous word", cmd_word_prev});
 	CommandRegistry::Register({CommandId::WordNext, "word-next", "Move to next word", cmd_word_next});
 	CommandRegistry::Register({

Command.h

@@ -58,6 +58,8 @@ enum class CommandId {
 	MoveEnd,
 	PageUp,
 	PageDown,
+	ScrollUp, // scroll viewport up (towards beginning) without moving cursor
+	ScrollDown, // scroll viewport down (towards end) without moving cursor
 	WordPrev,
 	WordNext,
 	DeleteWordPrev, // delete previous word (ESC BACKSPACE)

GUIInputHandler.cc

@@ -285,15 +285,11 @@ GUIInputHandler::ProcessSDLEvent(const SDL_Event &e)
 	bool produced = false;
 	switch (e.type) {
 	case SDL_MOUSEWHEEL: {
-		// If ImGui wants to capture the mouse (e.g., hovering the File Picker list),
-		// don't translate wheel events into editor scrolling.
-		// This prevents background buffer scroll while using GUI widgets.
-		ImGuiIO &io = ImGui::GetIO();
-		if (io.WantCaptureMouse) {
-			return true; // consumed by GUI
-		}
-
-		// Map vertical wheel to line-wise cursor movement (MoveUp/MoveDown)
+		// Map vertical wheel to viewport scrolling (ScrollUp/ScrollDown)
+		// Note: We don't check WantCaptureMouse here because ImGui sets it to true
+		// whenever the mouse is over any ImGui window (including our editor content area).
+		// The NoScrollWithMouse flag on the child window prevents ImGui from handling
+		// scroll internally, so we can safely process wheel events ourselves.
 		int dy = e.wheel.y;
 #ifdef SDL_MOUSEWHEEL_FLIPPED
 		if (e.wheel.direction == SDL_MOUSEWHEEL_FLIPPED)
@@ -301,7 +297,7 @@ GUIInputHandler::ProcessSDLEvent(const SDL_Event &e)
 #endif
 		if (dy != 0) {
 			int repeat   = dy > 0 ? dy : -dy;
-			CommandId id = dy > 0 ? CommandId::MoveUp : CommandId::MoveDown;
+			CommandId id = dy > 0 ? CommandId::ScrollUp : CommandId::ScrollDown;
 			std::lock_guard<std::mutex> lk(mu_);
 			for (int i = 0; i < repeat; ++i) {
 				q_.push(MappedInput{true, id, std::string(), 0});
@@ -372,7 +368,7 @@ GUIInputHandler::ProcessSDLEvent(const SDL_Event &e)
 			// Digits without shift, or a plain '-'
 			const bool is_digit_key = (key >= SDLK_0 && key <= SDLK_9) && !(mods & KMOD_SHIFT);
 			const bool is_minus_key = (key == SDLK_MINUS);
-			if (uarg_active_ && uarg_collecting_ && (is_digit_key || is_minus_key)) {
+			if (uarg_active_ && uarg_collecting_ &&(is_digit_key || is_minus_key)) {
 				suppress_text_input_once_ = true;
 			}
 		}
@@ -564,7 +560,12 @@ GUIInputHandler::ProcessSDLEvent(const SDL_Event &e)
 
 	if (produced && mi.hasCommand) {
 		// Attach universal-argument count if present, then clear the state
-		if (uarg_active_ && mi.id != CommandId::UArgStatus) {
+		if (uarg_active_ &&mi
+		
+		.
+		id != CommandId::UArgStatus
+		)
+		{
 			int count = 0;
 			if (!uarg_had_digits_ && !uarg_negative_) {
 				count = (uarg_value_ > 0) ? uarg_value_ : 4;
@@ -597,4 +598,4 @@ GUIInputHandler::Poll(MappedInput &out)
 	out = q_.front();
 	q_.pop();
 	return true;
-}
+}

TerminalInputHandler.cc

@@ -35,16 +35,16 @@ map_key_to_command(const int ch,
 	case KEY_MOUSE: {
 		MEVENT ev{};
 		if (getmouse(&ev) == OK) {
-			// Mouse wheel → map to MoveUp/MoveDown one line per wheel notch
+			// Mouse wheel → scroll viewport without moving cursor
 #ifdef BUTTON4_PRESSED
 			if (ev.bstate & (BUTTON4_PRESSED | BUTTON4_RELEASED | BUTTON4_CLICKED)) {
-				out = {true, CommandId::MoveUp, "", 0};
+				out = {true, CommandId::ScrollUp, "", 0};
 				return true;
 			}
 #endif
 #ifdef BUTTON5_PRESSED
 			if (ev.bstate & (BUTTON5_PRESSED | BUTTON5_RELEASED | BUTTON5_CLICKED)) {
-				out = {true, CommandId::MoveDown, "", 0};
+				out = {true, CommandId::ScrollDown, "", 0};
 				return true;
 			}
 #endif
@@ -320,4 +320,4 @@ TerminalInputHandler::Poll(MappedInput &out)
 {
 	out = {};
 	return decode_(out) && out.hasCommand;
-}
+}