auto-detect indentation

7 files changed, 84 insertions, 10 deletions

diff --git a/buffer.c b/buffer.c
index 9ef2467..63755d2 100644
--- a/buffer.c
+++ b/buffer.c
@@ -77,6 +77,14 @@ struct TextBuffer {
 	/// If set to true, buffer will be scrolled to the cursor position next frame.
 	/// This is to fix the problem that \ref x1, \ref y1, \ref x2, \ref y2 are not updated until the buffer is rendered.
 	bool center_cursor_next_frame;
+	/// whether to indent with spaces
+	///
+	/// this is either set according to the user's settings or according to the autodetected indentation
+	bool indent_with_spaces;
+	/// tab size
+	///
+	/// this is either set according to the user's settings or according to the autodetected indentation
+	uint8_t tab_width;
 	/// x coordinate of left side of buffer
 	float x1;
 	/// y coordinate of top side of buffer
@@ -359,6 +367,10 @@ static char *buffer_strdup(TextBuffer *buffer, const char *src) {
 static void buffer_set_up(Ted *ted, TextBuffer *buffer) {
 	buffer->store_undo_events = true;
 	buffer->ted = ted;
+	// will be overwritten by buffer_new_file, buffer_load_file for file buffers
+	const Settings *settings = buffer_settings(buffer);
+	buffer->indent_with_spaces = settings->indent_with_spaces;
+	buffer->tab_width = settings->tab_width;
 }
 
 static void line_buffer_set_up(Ted *ted, TextBuffer *buffer) {
@@ -544,11 +556,11 @@ void buffer_recompute_settings(TextBuffer *buffer) {
 }
 
 u8 buffer_tab_width(TextBuffer *buffer) {
-	return buffer_settings(buffer)->tab_width;
+	return buffer->tab_width;
 }
 
 bool buffer_indent_with_spaces(TextBuffer *buffer) {
-	return buffer_settings(buffer)->indent_with_spaces;
+	return buffer->indent_with_spaces;
 }
 
 u32 buffer_line_count(TextBuffer *buffer) {
@@ -2965,6 +2977,50 @@ void buffer_paste(TextBuffer *buffer) {
 	}
 }
 
+static void buffer_detect_indentation(TextBuffer *buffer) {
+	const Settings *settings = buffer_settings(buffer);
+	if (settings->autodetect_indentation && buffer->nlines > 1) {
+		bool use_tabs = false;
+		uint32_t spcs2 = 0, spcs4 = 0, spcs8 = 0;
+		for (uint32_t i = 0; i < buffer->nlines; i++) {
+			const Line *line = &buffer->lines[i];
+			if (line->len == 0) continue;
+			if (line->str[0] == '\t') {
+				use_tabs = true;
+				break;
+			}
+			uint32_t nspc = 0;
+			for (nspc = 0; nspc < line->len; nspc++) {
+				if (line->str[nspc] != ' ') {
+					break;
+				}
+			}
+			spcs2 += nspc == 2;
+			spcs4 += nspc == 4;
+			spcs8 += nspc == 8;
+		}
+		if (use_tabs) {
+			buffer->indent_with_spaces = false;
+			buffer->tab_width = settings->tab_width;
+		} else if (spcs2 * 50 > spcs4) {
+			buffer->indent_with_spaces = true;
+			buffer->tab_width = 2;
+		} else if (spcs4 * 50 > spcs8) {
+			buffer->indent_with_spaces = true;
+			buffer->tab_width = 4;
+		} else if (spcs8) {
+			buffer->indent_with_spaces = true;
+			buffer->tab_width = 8;
+		} else {
+			buffer->indent_with_spaces = settings->indent_with_spaces;
+			buffer->tab_width = settings->tab_width;
+		}
+	} else {
+		buffer->indent_with_spaces = settings->indent_with_spaces;
+		buffer->tab_width = settings->tab_width;
+	}
+}
+
 // if an error occurs, buffer is left untouched (except for the error field) and the function returns false.
 Status buffer_load_file(TextBuffer *buffer, const char *path) {
 	if (!unicode_is_valid_utf8(path)) {
@@ -3097,6 +3153,7 @@ Status buffer_load_file(TextBuffer *buffer, const char *path) {
 		buffer_error(buffer, "Couldn't open file %s: %s.", path, strerror(errno));
 		success = false;
 	}
+	buffer_detect_indentation(buffer);
 	return success;
 }
 
@@ -3137,6 +3194,9 @@ void buffer_new_file(TextBuffer *buffer, const char *path) {
 	buffer->lines_capacity = 4;
 	buffer->lines = buffer_calloc(buffer, buffer->lines_capacity, sizeof *buffer->lines);
 	buffer->nlines = 1;
+	const Settings *settings = buffer_settings(buffer);
+	buffer->indent_with_spaces = settings->indent_with_spaces;
+	buffer->tab_width = settings->tab_width;
 }
 
 static bool buffer_write_to_file(TextBuffer *buffer, const char *path) {
@@ -3295,6 +3355,7 @@ bool buffer_save_as(TextBuffer *buffer, const char *new_path) {
 		buffer->last_lsp_check = -INFINITY;
 		// we'll send a didOpen the next time buffer_lsp is called.
 		free(prev_path);
+		buffer_detect_indentation(buffer);
 		return true;
 	} else {
 		free(buffer->path);
diff --git a/config.c b/config.c
index 4eb536a..7bdcc7c 100644
--- a/config.c
+++ b/config.c
@@ -95,6 +95,7 @@ static const SettingBool settings_bool[] = {
 	{"auto-reload", &settings_zero.auto_reload, true},
 	{"auto-reload-config", &settings_zero.auto_reload_config, false},
 	{"syntax-highlighting", &settings_zero.syntax_highlighting, true},
+	{"autodetect-indentation", &settings_zero.autodetect_indentation, true},
 	{"line-numbers", &settings_zero.line_numbers, true},
 	{"restore-session", &settings_zero.restore_session, false},
 	{"regenerate-tags-if-not-found", &settings_zero.regenerate_tags_if_not_found, true},
@@ -115,7 +116,7 @@ static const SettingBool settings_bool[] = {
 #define SETTING_CRLF {"crlf", &settings_zero.crlf, true}
 	SETTING_CRLF,
 #define SETTING_CRLF_WINDOWS {"crlf-windows", &settings_zero.crlf_windows, true}
-	{"crlf-windows", &settings_zero.crlf_windows, true},
+	SETTING_CRLF_WINDOWS,
 	{"jump-to-build-error", &settings_zero.jump_to_build_error, true},
 	{"force-monospace", &settings_zero.force_monospace, true},
 	{"show-diagnostics", &settings_zero.show_diagnostics, true},
diff --git a/menu.c b/menu.c
index 7c7f16f..dce442b 100644
--- a/menu.c
+++ b/menu.c
@@ -540,7 +540,7 @@ void menu_init(Ted *ted) {
 	ted_add_edit_notify(ted, menu_edit_notify, ted);
 	
 	ted->command_selector = selector_new();
-        for (Command c = 0; c < CMD_COUNT; ++c) {
+	for (Command c = 0; c < CMD_COUNT; ++c) {
 		const char *name = command_to_str(c);
 		if (c != CMD_UNKNOWN && *name) {
 			SelectorEntry entry = {
@@ -548,7 +548,7 @@ void menu_init(Ted *ted) {
 			};
 			selector_add_entry(ted->command_selector, &entry);
 		}
-        }
+	}
 	
 	MenuInfo save_as_menu = {
 		.open = save_as_menu_open,
diff --git a/node.c b/node.c
index f4fe8fc..8f32087 100644
--- a/node.c
+++ b/node.c
@@ -418,8 +418,11 @@ void node_frame(Ted *ted, Node *node, Rect r) {
 					// highlight active tab
 					gl_geometry_rect(tab_rect, settings_color(settings, is_active ? COLOR_ACTIVE_TAB_HL : COLOR_SELECTED_TAB_HL));
 					// set window title to active tab's title
-					strbuf_printf(ted->window_title, "ted %s | %s", tab_title,
-						settings->indent_with_spaces ? "spaces" : "tabs");
+					strbuf_printf(ted->window_title, "ted %s | ", tab_title);
+					if (buffer_indent_with_spaces(buffer))
+						strbuf_catf(ted->window_title, "%u spaces", buffer_tab_width(buffer));
+					else
+						strbuf_catf(ted->window_title, "tabs");
 					if (*rc_str(settings->lsp, "")) {
 						LSP *lsp = buffer_lsp(buffer);
 						strbuf_catf(ted->window_title, " | LSP %s",
diff --git a/ted-internal.h b/ted-internal.h
index c8a72c3..f5e3211 100644
--- a/ted-internal.h
+++ b/ted-internal.h
@@ -121,6 +121,7 @@ struct Settings {
 	bool jump_to_build_error;
 	bool force_monospace;
 	bool show_diagnostics;
+	bool autodetect_indentation;
 	KeyCombo hover_key;
 	KeyCombo highlight_key;
 	u8 tab_width;
diff --git a/ted.cfg b/ted.cfg
index 702284b..ea59963 100644
--- a/ted.cfg
+++ b/ted.cfg
@@ -3,6 +3,14 @@
 [core]
 tab-width = 4
 indent-with-spaces = off
+# if enabled, indentation type will be automatically detected from file when possible
+# how this currently works:
+#  1. if any lines start with a tab character, tabs are used
+#  2. otherwise, if # 4-spaced lines / 50 < # 2-spaced lines, 2 spaces are used
+#  3. otherwise, if # 8-spaced lines / 50 < # 4-spaced lines, 4 spaces are used
+#  4. otherwise, if any lines start with exactly 8 spaces, 8 spaces are used
+#  5. otherwise, your default settings are used
+autodetect-indentation = on
 # cursor width in pixels
 cursor-width = 1
 # time to blink cursor for (i.e. it will be on for cursor-blink-time-on seconds, then off for cursor-blink-time-off seconds)
diff --git a/ui.c b/ui.c
index 995c631..2af72fa 100644
--- a/ui.c
+++ b/ui.c
@@ -501,9 +501,9 @@ static bool file_selector_cd(Ted *ted, FileSelector *fs, const char *path) {
 
 static ColorSetting color_setting_for_file_type(FsType type) {
 	switch (type) {
-        case FS_FILE: return COLOR_TEXT;
-        case FS_DIRECTORY: return COLOR_TEXT_FOLDER;
-        default: return COLOR_TEXT_OTHER;
+	case FS_FILE: return COLOR_TEXT;
+	case FS_DIRECTORY: return COLOR_TEXT_FOLDER;
+	default: return COLOR_TEXT_OTHER;
 	}
 }