Enable multi-select

Default multi-select key is Ctrl+s

fzy.1

@@ -52,7 +52,7 @@ Usage help.
 .
 .TP
 .BR "ENTER"
-Print the selected item to stdout and exit
+Print the selected item (or all multi-selected items) to stdout and exit
 .TP
 .BR "Ctrl+c, Esc"
 Exit with status 1, without making a selection.
@@ -63,7 +63,7 @@ Select the previous item
 .BR "Down Arrow, Ctrl+n"
 Select the next item
 .TP
-Tab
+.BR Tab
 Replace the current search string with the selected item
 .TP
 .BR "Backspace, Ctrl+h"
@@ -74,6 +74,10 @@ Delete the word before the cursor
 .TP
 .BR Ctrl+u
 Delete the entire line
+.TP
+.BR Ctrl+s
+Multi-select the current item. Each multi-selected item will be printed on
+its own line.
 .
 .SH USAGE EXAMPLES
 .

src/choices.c

@@ -94,13 +94,15 @@ static void choices_resize(choices_t *c, size_t new_capacity) {
 
 static void choices_reset_search(choices_t *c) {
 	free(c->results);
-	c->selection = c->available = 0;
 	c->results = NULL;
+	c->selection = c->available = 0;
 }
 
 void choices_init(choices_t *c, options_t *options) {
 	c->strings = NULL;
 	c->results = NULL;
+	c->selections = NULL;
+	c->num_selections = 0;
 
 	c->buffer_size = 0;
 	c->buffer = NULL;
@@ -129,6 +131,10 @@ void choices_destroy(choices_t *c) {
 	free(c->results);
 	c->results = NULL;
 	c->available = c->selection = 0;
+
+	free(c->selections);
+	c->selections = NULL;
+	c->num_selections = 0;
 }
 
 void choices_add(choices_t *c, const char *choice) {
@@ -141,6 +147,37 @@ void choices_add(choices_t *c, const char *choice) {
 	c->strings[c->size++] = choice;
 }
 
+void choices_select(choices_t *c, const char *choice) {
+	if (!c->selections) {
+		c->num_selections = 1;
+		c->selections = malloc(sizeof(char *));
+		c->selections[0] = choice;
+	} else if (!choices_selected(c, choice)) {
+		c->num_selections++;
+		c->selections = realloc(c->selections, c->num_selections * sizeof(char *));
+		c->selections[c->num_selections - 1] = choice;
+	}
+}
+
+void choices_deselect(choices_t *c, const char *choice) {
+	for (size_t i = 0; i < c->num_selections; i++) {
+		if (c->selections[i] == choice) {
+			c->selections[i] = NULL;
+			c->num_selections--;
+			break;
+		}
+	}
+}
+
+bool choices_selected(choices_t *c, const char *choice) {
+	for (size_t i = 0; i < c->num_selections; i++) {
+		if (c->selections[i] == choice) {
+			return true;
+		}
+	}
+	return false;
+}
+
 size_t choices_available(choices_t *c) {
 	return c->available;
 }

src/choices.h

@@ -1,6 +1,7 @@
 #ifndef CHOICES_H
 #define CHOICES_H CHOICES_H
 
+#include <stdbool.h>
 #include <stdio.h>
 
 #include "match.h"
@@ -24,13 +25,19 @@ typedef struct {
 	size_t available;
 	size_t selection;
 
+        const char **selections;
+        size_t num_selections;
+
 	unsigned int worker_count;
 } choices_t;
 
 void choices_init(choices_t *c, options_t *options);
 void choices_fread(choices_t *c, FILE *file, char input_delimiter);
 void choices_destroy(choices_t *c);
 void choices_add(choices_t *c, const char *choice);
+void choices_select(choices_t *c, const char *choice);
+void choices_deselect(choices_t *c, const char *choice);
+bool choices_selected(choices_t *c, const char *choice);
 size_t choices_available(choices_t *c);
 void choices_search(choices_t *c, const char *search);
 const char *choices_get(choices_t *c, size_t n);

src/tty.c

@@ -148,9 +148,13 @@ void tty_setunderline(tty_t *tty) {
 	tty_sgr(tty, 4);
 }
 
+void tty_setbold(tty_t *tty) {
+	tty_sgr(tty, 1);
+}
+
 void tty_setnormal(tty_t *tty) {
 	tty_sgr(tty, 0);
-	tty->fgcolor = 9;
+	tty->fgcolor = TTY_COLOR_NORMAL;
 }
 
 void tty_setnowrap(tty_t *tty) {

src/tty.h

@@ -22,6 +22,7 @@ int tty_input_ready(tty_t *tty, long int timeout, int return_on_signal);
 void tty_setfg(tty_t *tty, int fg);
 void tty_setinvert(tty_t *tty);
 void tty_setunderline(tty_t *tty);
+void tty_setbold(tty_t *tty);
 void tty_setnormal(tty_t *tty);
 void tty_setnowrap(tty_t *tty);
 void tty_setwrap(tty_t *tty);

src/tty_interface.c

@@ -50,6 +50,10 @@ static void draw_match(tty_interface_t *state, const char *choice, int selected)
 		}
 	}
 
+	if (choices_selected(state->choices, choice)) {
+		tty_setbold(tty);
+	}
+
 	if (selected)
 #ifdef TTY_SELECTION_UNDERLINE
 		tty_setunderline(tty);
@@ -124,6 +128,17 @@ static void update_state(tty_interface_t *state) {
 	}
 }
 
+static void action_select(tty_interface_t *state) {
+	update_state(state);
+
+	const char *selection = choices_get(state->choices, state->choices->selection);
+	if (choices_selected(state->choices, selection)) {
+		choices_deselect(state->choices, selection);
+	} else {
+		choices_select(state->choices, selection);
+	}
+}
+
 static void action_emit(tty_interface_t *state) {
 	update_state(state);
 
@@ -133,13 +148,21 @@ static void action_emit(tty_interface_t *state) {
 	/* ttyout should be flushed before outputting on stdout */
 	tty_close(state->tty);
 
-	const char *selection = choices_get(state->choices, state->choices->selection);
-	if (selection) {
-		/* output the selected result */
-		printf("%s\n", selection);
+	/* If no choices were selected with multi-select, use the choice under
+	 * the cursor */
+	if (!state->choices->num_selections) {
+		const char *selection = choices_get(state->choices, state->choices->selection);
+		if (selection) {
+			/* output the result */
+			printf("%s\n", selection);
+		} else {
+			/* No match, output the query instead */
+			printf("%s\n", state->search);
+		}
 	} else {
-		/* No match, output the query instead */
-		printf("%s\n", state->search);
+		for (size_t i = 0; i < state->choices->num_selections; i++) {
+			printf("%s\n", state->choices->selections[i]);
+		}
 	}
 
 	state->exit = EXIT_SUCCESS;
@@ -258,6 +281,7 @@ static void append_search(tty_interface_t *state, char ch) {
 void tty_interface_init(tty_interface_t *state, tty_t *tty, choices_t *choices, options_t *options) {
 	state->tty = tty;
 	state->choices = choices;
+
 	state->options = options;
 	state->ambiguous_key_pending = 0;
 
@@ -292,6 +316,7 @@ static const keybinding_t keybindings[] = {{"\x1b", action_exit},       /* ESC *
 					   {KEY_CTRL('C'), action_exit},	 /* C-C */
 					   {KEY_CTRL('D'), action_exit},	 /* C-D */
 					   {KEY_CTRL('M'), action_emit},	 /* CR */
+					   {KEY_CTRL('S'), action_select},	 /* C-S */
 					   {KEY_CTRL('P'), action_prev},	 /* C-P */
 					   {KEY_CTRL('N'), action_next},	 /* C-N */
 					   {KEY_CTRL('K'), action_prev},	 /* C-K */

test/test_choices.c

@@ -29,6 +29,7 @@ TEST test_choices_empty() {
 	ASSERT_SIZE_T_EQ(0, choices.size);
 	ASSERT_SIZE_T_EQ(0, choices.available);
 	ASSERT_SIZE_T_EQ(0, choices.selection);
+	ASSERT_SIZE_T_EQ(0, choices.num_selections);
 
 	choices_prev(&choices);
 	ASSERT_SIZE_T_EQ(0, choices.selection);
@@ -157,6 +158,30 @@ TEST test_choices_large_input() {
 	PASS();
 }
 
+TEST test_choices_multi_select() {
+	choices_add(&choices, "tags");
+	choices_add(&choices, "test");
+	choices_search(&choices, "");
+
+	const char *first_choice = choices_get(&choices, 0);
+	ASSERT_FALSE(choices_selected(&choices, first_choice));
+	choices_select(&choices, first_choice);
+	ASSERT_FALSE(!choices_selected(&choices, first_choice));
+	ASSERT_SIZE_T_EQ(1, choices.num_selections);
+
+	const char *second_choice = choices_get(&choices, 1);
+	ASSERT_FALSE(choices_selected(&choices, second_choice));
+	choices_select(&choices, second_choice);
+	ASSERT_FALSE(!choices_selected(&choices, second_choice));
+	ASSERT_SIZE_T_EQ(2, choices.num_selections);
+
+	choices_deselect(&choices, second_choice);
+	ASSERT_FALSE(choices_selected(&choices, second_choice));
+	ASSERT_SIZE_T_EQ(1, choices.num_selections);
+
+	PASS();
+}
+
 SUITE(choices_suite) {
 	SET_SETUP(setup, NULL);
 	SET_TEARDOWN(teardown, NULL);
@@ -167,4 +192,5 @@ SUITE(choices_suite) {
 	RUN_TEST(test_choices_without_search);
 	RUN_TEST(test_choices_unicode);
 	RUN_TEST(test_choices_large_input);
+	RUN_TEST(test_choices_multi_select);
 }