From 7313cb05951e83b312fd1e2ae865e9579c2bbc0c Mon Sep 17 00:00:00 2001
From: Gregory Anders <greg@gpanders.com>
Date: Mon, 21 Dec 2020 19:13:02 -0700
Subject: [PATCH 1/5] Enable multi-select

Default multi-select key is Ctrl+s
---
 fzy.1               |  8 ++++++--
 src/choices.c       | 39 ++++++++++++++++++++++++++++++++++++++-
 src/choices.h       |  7 +++++++
 src/tty.c           |  6 +++++-
 src/tty.h           |  1 +
 src/tty_interface.c | 37 +++++++++++++++++++++++++++++++------
 test/test_choices.c | 26 ++++++++++++++++++++++++++
 7 files changed, 114 insertions(+), 10 deletions(-)

diff --git a/fzy.1 b/fzy.1
index 79dbad7..96250eb 100644
--- a/fzy.1
+++ b/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, Ctrl+g, 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
 .
diff --git a/src/choices.c b/src/choices.c
index fe2f80b..1244d06 100644
--- a/src/choices.c
+++ b/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;
 }
diff --git a/src/choices.h b/src/choices.h
index 925478e..222bdb5 100644
--- a/src/choices.h
+++ b/src/choices.h
@@ -1,6 +1,7 @@
 #ifndef CHOICES_H
 #define CHOICES_H CHOICES_H
 
+#include <stdbool.h>
 #include <stdio.h>
 
 #include "match.h"
@@ -24,6 +25,9 @@ typedef struct {
 	size_t available;
 	size_t selection;
 
+        const char **selections;
+        size_t num_selections;
+
 	unsigned int worker_count;
 } choices_t;
 
@@ -31,6 +35,9 @@ 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);
diff --git a/src/tty.c b/src/tty.c
index 733477e..1f66ec8 100644
--- a/src/tty.c
+++ b/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) {
diff --git a/src/tty.h b/src/tty.h
index 013360e..f19d52f 100644
--- a/src/tty.h
+++ b/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);
diff --git a/src/tty_interface.c b/src/tty_interface.c
index 343dde8..1839857 100644
--- a/src/tty_interface.c
+++ b/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);
@@ -131,6 +135,17 @@ 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);
 
@@ -140,13 +155,21 @@ 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;
@@ -265,6 +288,7 @@ 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;
 
@@ -300,6 +324,7 @@ static const keybinding_t keybindings[] = {{"\x1b", action_exit},       /* ESC *
 					   {KEY_CTRL('D'), action_exit},	 /* C-D */
 					   {KEY_CTRL('G'), action_exit},	 /* C-G */
 					   {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 */
diff --git a/test/test_choices.c b/test/test_choices.c
index d86bc12..86b764b 100644
--- a/test/test_choices.c
+++ b/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);
 }

From f37b488824117663f1326c399d61923ed785fa2c Mon Sep 17 00:00:00 2001
From: Gregory Anders <greg@gpanders.com>
Date: Mon, 21 Dec 2020 19:13:02 -0700
Subject: [PATCH 2/5] Clean-up multiselect code

Allocate memory for the multiselect buffer in chunks, similar to how the
`choices` buffer is resized. This results in potentially more unused
(i.e. wasted) memory, but in fewer invocations of `malloc`/`realloc`,
which is probably more important, considering the size of the
multiselect array will never be that large.
---
 src/choices.c       | 53 +++++++++++++++++++++++++++++----------------
 src/choices.h       |  8 +++++--
 src/tty_interface.c |  6 ++---
 test/test_choices.c | 23 ++++++++++----------
 4 files changed, 55 insertions(+), 35 deletions(-)

diff --git a/src/choices.c b/src/choices.c
index 1244d06..09733d6 100644
--- a/src/choices.c
+++ b/src/choices.c
@@ -15,6 +15,9 @@
 /* Initial size of choices array */
 #define INITIAL_CHOICE_CAPACITY 128
 
+/* Initial size of multi-selection buffer */
+#define INITIAL_SELECTIONS_CAPACITY 8
+
 static int cmpchoice(const void *_idx1, const void *_idx2) {
 	const struct scored_result *a = _idx1;
 	const struct scored_result *b = _idx2;
@@ -92,6 +95,11 @@ static void choices_resize(choices_t *c, size_t new_capacity) {
 	c->capacity = new_capacity;
 }
 
+static void choices_resize_selections(choices_t *c, size_t new_capacity) {
+	c->selections.strings = safe_realloc(c->selections.strings, new_capacity * sizeof(const char *));
+	c->selections.capacity = new_capacity;
+}
+
 static void choices_reset_search(choices_t *c) {
 	free(c->results);
 	c->results = NULL;
@@ -101,8 +109,8 @@ static void choices_reset_search(choices_t *c) {
 void choices_init(choices_t *c, options_t *options) {
 	c->strings = NULL;
 	c->results = NULL;
-	c->selections = NULL;
-	c->num_selections = 0;
+	c->selections.strings = NULL;
+	c->selections.capacity = c->selections.size = 0;
 
 	c->buffer_size = 0;
 	c->buffer = NULL;
@@ -132,9 +140,9 @@ void choices_destroy(choices_t *c) {
 	c->results = NULL;
 	c->available = c->selection = 0;
 
-	free(c->selections);
-	c->selections = NULL;
-	c->num_selections = 0;
+	free(c->selections.strings);
+	c->selections.strings = NULL;
+	c->selections.capacity = c->selections.size = 0;
 }
 
 void choices_add(choices_t *c, const char *choice) {
@@ -148,30 +156,37 @@ void choices_add(choices_t *c, const char *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;
+	if (c->selections.size == c->selections.capacity) {
+		if (c->selections.capacity == 0) {
+			choices_resize_selections(c, INITIAL_SELECTIONS_CAPACITY);
+		} else {
+			choices_resize_selections(c, c->selections.capacity * 2);
+		}
+	}
+
+	if (!choices_selected(c, choice)) {
+		c->selections.strings[c->selections.size++] = 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--;
+	size_t index = c->selections.size;
+	for (size_t i = 0; i < c->selections.size; i++) {
+		if (c->selections.strings[i] == choice) {
+			c->selections.size--;
+			index = i;
 			break;
 		}
 	}
+
+	for (size_t i = index; i < c->selections.size; i++) {
+		c->selections.strings[i] = c->selections.strings[i+1];
+	}
 }
 
 bool choices_selected(choices_t *c, const char *choice) {
-	for (size_t i = 0; i < c->num_selections; i++) {
-		if (c->selections[i] == choice) {
+	for (size_t i = 0; i < c->selections.size; i++) {
+		if (c->selections.strings[i] == choice) {
 			return true;
 		}
 	}
diff --git a/src/choices.h b/src/choices.h
index 222bdb5..50ef7dc 100644
--- a/src/choices.h
+++ b/src/choices.h
@@ -25,8 +25,12 @@ typedef struct {
 	size_t available;
 	size_t selection;
 
-        const char **selections;
-        size_t num_selections;
+	struct {
+		const char **strings;
+
+		size_t capacity;
+		size_t size;
+	} selections;
 
 	unsigned int worker_count;
 } choices_t;
diff --git a/src/tty_interface.c b/src/tty_interface.c
index 1839857..07fbeda 100644
--- a/src/tty_interface.c
+++ b/src/tty_interface.c
@@ -157,7 +157,7 @@ static void action_emit(tty_interface_t *state) {
 
 	/* If no choices were selected with multi-select, use the choice under
 	 * the cursor */
-	if (!state->choices->num_selections) {
+	if (!state->choices->selections.size) {
 		const char *selection = choices_get(state->choices, state->choices->selection);
 		if (selection) {
 			/* output the result */
@@ -167,8 +167,8 @@ static void action_emit(tty_interface_t *state) {
 			printf("%s\n", state->search);
 		}
 	} else {
-		for (size_t i = 0; i < state->choices->num_selections; i++) {
-			printf("%s\n", state->choices->selections[i]);
+		for (size_t i = 0; i < state->choices->selections.size; i++) {
+			printf("%s\n", state->choices->selections.strings[i]);
 		}
 	}
 
diff --git a/test/test_choices.c b/test/test_choices.c
index 86b764b..858e88f 100644
--- a/test/test_choices.c
+++ b/test/test_choices.c
@@ -9,27 +9,28 @@
 #include "greatest/greatest.h"
 
 #define ASSERT_SIZE_T_EQ(a,b) ASSERT_EQ_FMT((size_t)(a), (b), "%zu")
+#define ASSERT_TRUE(cond) ASSERT_FALSE(!cond)
 
 static options_t default_options;
 static choices_t choices;
 
 static void setup(void *udata) {
-    (void)udata;
+	(void)udata;
 
-    options_init(&default_options);
-    choices_init(&choices, &default_options);
+	options_init(&default_options);
+	choices_init(&choices, &default_options);
 }
 
 static void teardown(void *udata) {
-    (void)udata;
-    choices_destroy(&choices);
+	(void)udata;
+	choices_destroy(&choices);
 }
 
 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);
+	ASSERT_SIZE_T_EQ(0, choices.selections.size);
 
 	choices_prev(&choices);
 	ASSERT_SIZE_T_EQ(0, choices.selection);
@@ -166,18 +167,18 @@ TEST test_choices_multi_select() {
 	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);
+	ASSERT_TRUE(choices_selected(&choices, first_choice));
+	ASSERT_SIZE_T_EQ(1, choices.selections.size);
 
 	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);
+	ASSERT_TRUE(choices_selected(&choices, second_choice));
+	ASSERT_SIZE_T_EQ(2, choices.selections.size);
 
 	choices_deselect(&choices, second_choice);
 	ASSERT_FALSE(choices_selected(&choices, second_choice));
-	ASSERT_SIZE_T_EQ(1, choices.num_selections);
+	ASSERT_SIZE_T_EQ(1, choices.selections.size);
 
 	PASS();
 }

From 6027a95095fa3c1d8158131c8a216dbd26313995 Mon Sep 17 00:00:00 2001
From: Gregory Anders <greg@gpanders.com>
Date: Mon, 21 Dec 2020 19:13:02 -0700
Subject: [PATCH 3/5] Only add non-null selections

---
 src/tty_interface.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/tty_interface.c b/src/tty_interface.c
index 07fbeda..c9fdcc7 100644
--- a/src/tty_interface.c
+++ b/src/tty_interface.c
@@ -139,10 +139,12 @@ 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);
+	if (selection) {
+		if (choices_selected(state->choices, selection)) {
+			choices_deselect(state->choices, selection);
+		} else {
+			choices_select(state->choices, selection);
+		}
 	}
 }
 

From 7e8bc19a45ac8821051a01a39a1bf6859f8e45e8 Mon Sep 17 00:00:00 2001
From: Gregory Anders <greg@gpanders.com>
Date: Mon, 21 Dec 2020 19:13:02 -0700
Subject: [PATCH 4/5] Move cursor to next choice after multi-(de)selecting

---
 src/tty_interface.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/tty_interface.c b/src/tty_interface.c
index c9fdcc7..381d46d 100644
--- a/src/tty_interface.c
+++ b/src/tty_interface.c
@@ -145,6 +145,7 @@ static void action_select(tty_interface_t *state) {
 		} else {
 			choices_select(state->choices, selection);
 		}
+		choices_next(state->choices);
 	}
 }
 

From fca09040b7f57d8f5a7e89654df7695968e52299 Mon Sep 17 00:00:00 2001
From: Gregory Anders <greg@gpanders.com>
Date: Mon, 21 Dec 2020 19:13:02 -0700
Subject: [PATCH 5/5] Change multi-select key to Ctrl+t (mnemonic: "tag")

---
 fzy.1               | 2 +-
 src/tty_interface.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fzy.1 b/fzy.1
index 96250eb..0a181b9 100644
--- a/fzy.1
+++ b/fzy.1
@@ -75,7 +75,7 @@ Delete the word before the cursor
 .BR Ctrl+u
 Delete the entire line
 .TP
-.BR Ctrl+s
+.BR Ctrl+t
 Multi-select the current item. Each multi-selected item will be printed on
 its own line.
 .
diff --git a/src/tty_interface.c b/src/tty_interface.c
index 381d46d..25e4b16 100644
--- a/src/tty_interface.c
+++ b/src/tty_interface.c
@@ -327,7 +327,7 @@ static const keybinding_t keybindings[] = {{"\x1b", action_exit},       /* ESC *
 					   {KEY_CTRL('D'), action_exit},	 /* C-D */
 					   {KEY_CTRL('G'), action_exit},	 /* C-G */
 					   {KEY_CTRL('M'), action_emit},	 /* CR */
-					   {KEY_CTRL('S'), action_select},	 /* C-S */
+					   {KEY_CTRL('T'), action_select},	 /* C-T */
 					   {KEY_CTRL('P'), action_prev},	 /* C-P */
 					   {KEY_CTRL('N'), action_next},	 /* C-N */
 					   {KEY_CTRL('K'), action_prev},	 /* C-K */