From ab99ea260b5604109b7c427b0dc71d220bb6d09a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89rico=20Rolim?= <erico.erc@gmail.com>
Date: Thu, 7 Jan 2021 17:34:44 -0300
Subject: [PATCH] Switch to using a pad for the list, add working navigation.

---
 browser.c      | 67 +++++++++++++++++++++++++++++++++++++++-----------
 string-array.c |  9 +++++--
 string-array.h | 14 +++++++++--
 3 files changed, 72 insertions(+), 18 deletions(-)

diff --git a/browser.c b/browser.c
index 2e0a45b..25b3268 100644
--- a/browser.c
+++ b/browser.c
@@ -35,6 +35,7 @@ int main()
 
 	struct str_array entries = { 0 };
 	read_entries_from_stream(&entries, delim, stdin);
+	filter_entries(&entries, NULL);
 
 	int tmp_fd;
 	/* use stderr for input instead of stdin, since we get the entries from stdin */
@@ -68,21 +69,22 @@ int main()
 	/* noop function - should use the windows from below */
 	attrset(COLOR_PAIR(1));
 
-	WINDOW *list = newwin(LINES - 1, 0, 0, 0);
+	/* store number of rows that can be displayed in list */
+	const int nrows = LINES - 1;
+
+	WINDOW *list = newpad(entries.n, COLS);
 	WINDOW *prompt = newwin(1, 0, LINES - 1, 0);
 	if (!list || !prompt) {
 		perror("newwin");
 		exit(1);
 	}
 	keypad(prompt, TRUE);
-	keypad(list, TRUE);
 
-	/* inital dump of list
-	 * TODO: needs scroll support */
+	/* inital dump of list */
 	for (size_t i = 0; i < entries.n; i++) {
 		mvwaddstr(list, i, 0, get_entry(&entries, i));
 	}
-	wrefresh(list);
+	prefresh(list, 0, 0, 0, 0, nrows - 1, COLS);
 
 	mvwaddstr(prompt, 0, 0, "> ");
 	wrefresh(prompt);
@@ -91,29 +93,64 @@ int main()
 	 * TODO: use dynamic string and str_array so we can search on a group of tokens */
 	char name[1024] = { 0 };
 	size_t n = 0;
-	while (n < sizeof name) {
+	/* listx isn't changed anywhere */
+	int listx = 0, listy = 0;
+	while (n < sizeof name - 1) {
+		bool name_changed = false;
 		int c = wgetch(prompt);
 		switch (c) {
+			/* Ctrl+[ or ESC */
+			case 27:
+				exit(1);
+				break;
+
 			case KEY_ENTER:
 			case '\r':
 				/* since we are using nonl above, only capture '\r' itself
 				 * TODO: actually store the entry name */
 				final_name = name;
 				exit(0);
-			case KEY_BACKSPACE:
-			case 127:
-				name[n] = 0;
-				if (n) n--;
+
+			case KEY_DOWN:
+			/* Ctrl-N */
+			case 14:
+				if ((size_t)listy < entries.n && (size_t)nrows < entries.ms ) listy++;
 				break;
-			case KEY_DL:
-				name[0] = 0;
+
+			case KEY_UP:
+			/* Ctrl-P */
+			case 16:
+				if (listy) listy--;
+				break;
+
+			/* Ctrl+W */
+			case 23:
 				n = 0;
+				name[n] = 0;
+				name_changed = true;
 				break;
+
+			case KEY_BACKSPACE:
+			/* DEL */
+			case 127:
+				if (n) n--;
+				name[n] = 0;
+				name_changed = true;
+				break;
+
 			default:
 				name[n] = c;
 				n++;
+				/* clear chars from previous entries */
+				name[n] = 0;
+				name_changed = true;
 				break;
 		}
+		if (!name_changed) {
+			prefresh(list, listy, listx, 0, 0, nrows-1, COLS);
+			continue;
+		}
+
 		werase(prompt);
 		mvwaddstr(prompt, 0, 0, "> ");
 		waddstr(prompt, name);
@@ -123,10 +160,12 @@ int main()
 		werase(list);
 		int line = 0;
 		for (size_t i = 0; i < entries.n; i++) {
-			const char *e = get_entry_match(&entries, i);
+			const char *e = get_entry_if_match(&entries, i);
 			if (e) mvwaddstr(list, line++, 0, e);
 		}
-		wrefresh(list);
+		/* reset vertical position when name changes */
+		listy = 0;
+		prefresh(list, listy, listx, 0, 0, nrows-1, COLS);
 	}
 
 	return 0;
diff --git a/string-array.c b/string-array.c
index 737bab6..c736feb 100644
--- a/string-array.c
+++ b/string-array.c
@@ -18,14 +18,19 @@ void add_entry(struct str_array *a, const char *s)
 	}
 
 	a->v[a->n] = s;
-	a->m[a->n] = false;
 	a->n++;
 }
 
 void filter_entries(struct str_array *a, const char *s)
 {
+	if (!s) {
+		a->ms = a->n;
+		return;
+	}
+
+	a->ms = 0;
 	for (size_t i = 0; i < a->n; i++) {
-		a->m[i] = strstr(a->v[i], s);
+		if ((a->m[i] = strstr(a->v[i], s))) a->ms++;
 	}
 }
 
diff --git a/string-array.h b/string-array.h
index 036bba5..4a6959f 100644
--- a/string-array.h
+++ b/string-array.h
@@ -4,8 +4,13 @@
 #include <stdbool.h>
 
 struct str_array {
+	/* strings in the array */
 	const char **v;
+	/* flag to say if they fit a certain condition or not */
 	bool *m;
+	/* total number of true in m */
+	size_t ms;
+	/* number of elements, maximum number of elements */
 	size_t n, c;
 };
 
@@ -15,9 +20,14 @@ static inline const char *get_entry(const struct str_array *a, size_t i)
 	return a->v[i];
 }
 
-static inline const char *get_entry_match(const struct str_array *a, size_t i)
+static inline bool get_entry_match(const struct str_array *a, size_t i)
 {
-	return a->m[i] ? a->v[i] : NULL;
+	return a->m[i];
+}
+
+static inline const char *get_entry_if_match(const struct str_array *a, size_t i)
+{
+	return get_entry_match(a, i) ? a->v[i] : NULL;
 }
 
 void add_entry(struct str_array *, const char *);