Refactor everything into it's own file

.gitignore

@@ -2,4 +2,5 @@ build/
 kilo
 
 .cache
+.clangd
 compile_commands.json

Makefile

@@ -6,7 +6,7 @@ WARNING_FLAGS := -Wall -Wextra
 INCLUDE_FLAGS := -I include
 
 CC := clang
-CFLAGS := $(WARNING_FLAGS) $(INCLUDE_FLAGS) -MMD -MP -std=c99
+CFLAGS := $(WARNING_FLAGS) $(INCLUDE_FLAGS) -MMD -MP -std=c99 -ggdb
 
 kilo: $(OBJS)
 	$(CC) $(CFLAGS) $^ -o $@

include/append_buf.h

@@ -1,15 +0,0 @@
-#ifndef APPEND_BUF_H
-#define APPEND_BUF_H
-
-// A simple append only buffer to build strings
-
-struct append_buf {
-    char *chars;
-    int n_chars;
-};
-
-struct append_buf *ab_init(void);
-void ab_append(struct append_buf *ab, const char *chars, int n_chars);
-void ab_free(struct append_buf *ab);
-
-#endif // APPEND_BUF_H

include/buffer.h

@@ -0,0 +1,26 @@
+#ifndef BUFFER_H
+#define BUFFER_H
+
+struct erow {
+    char *chars;
+    int n_chars;
+
+    char *rchars;
+    int n_rchars;
+};
+
+struct buffer {
+    char *filename;
+    struct erow *rows;
+    int n_rows;
+};
+
+struct buffer *buffer_create(void);
+void buffer_read_file(struct buffer *buffer, const char *filename);
+void buffer_append_row(struct buffer *buffer, const char *chars, int n_chars);
+
+void erow_update_rendering(struct erow *erow);
+int erow_cx_to_rx(struct erow *erow, int cx);
+int erow_rx_to_cx(struct erow *erow, int rx);
+
+#endif // BUFFER_H

include/commands.h

@@ -0,0 +1,8 @@
+#ifndef COMMANDS_H
+#define COMMANDS_H
+
+#include "input.h"
+
+void editor_move_cursor(KEY key);
+
+#endif // COMMANDS_H

include/input.h

@@ -0,0 +1,23 @@
+#ifndef INPUT_H
+#define INPUT_H
+
+#include <stdint.h>
+
+enum KEYS {
+    TAB = 9,
+    HOME = 0x100,
+    DEL,
+    PG_UP,
+    PG_DOWN,
+    END,
+    ARROW_UP,
+    ARROW_DOWN,
+    ARROW_LEFT,
+    ARROW_RIGHT,
+    NOP
+};
+typedef uint16_t KEY;
+
+void input_process_key(void);
+
+#endif // INPUT_H

include/kilo.h

@@ -1,47 +1,23 @@
 #ifndef KILO_H
 #define KILO_H
 
-#include <stdbool.h>
-#include <stdint.h>
+#define KILO_VERSION "0.0.1"
+#define KILO_TAB_STOP 4
+
 #include <termios.h>
 #include <time.h>
 
-// Stuff I couldn' figure out where else to put
-
-typedef int ERRCODE;
-
 struct editor_state {
-    char *filename;
-    int cx, cy;
-    int rx;
-    int screenrows, screencols;
+    int cx, cy, rx;
     int row_off, col_off;
+    int screenrows, screencols;
 
-    struct EROW *rows;
-    int n_rows;
+    struct buffer *current_buf;
+    struct termios orig_termios;
 
     char message[256];
     time_t message_time;
-
-    struct termios orig_termios;
 };
 extern struct editor_state E;
 
-enum KEYS {
-    TAB = 9,
-    HOME = 0x100,
-    DEL,
-    PG_UP,
-    PG_DOWN,
-    END,
-    ARROW_UP,
-    ARROW_DOWN,
-    ARROW_LEFT,
-    ARROW_RIGHT,
-    NOP
-};
-typedef uint16_t KEY;
-
-void die(const char *context);
-
 #endif // KILO_H

include/terminal.h

@@ -1,9 +1,8 @@
 #ifndef TERMINAL_H
 #define TERMINAL_H
 
-#include <stdbool.h>
-
-#include "kilo.h"
+#include "input.h"
+#include "utils.h"
 
 // Functions to perform low level terminal operations, using escape codes
 

include/ui.h

@@ -0,0 +1,6 @@
+#ifndef UI_H
+#define UI_H
+
+void ui_draw_screen(void);
+
+#endif // UI_H

include/utils.h

@@ -0,0 +1,24 @@
+#ifndef UTIL_H
+#define UTIL_H
+
+#define CTRL_KEY(key) ((key) & 0x1f)
+
+#define MAX(a,b) (((a)>(b))?(a):(b))
+#define MIN(a,b) (((a)<(b))?(a):(b))
+
+typedef int ERRCODE;
+
+void die(const char *context);
+
+/*****************************************************************************/
+
+struct append_buf {
+    char *chars;
+    int n_chars;
+};
+
+struct append_buf *ab_create(void);
+void ab_append(struct append_buf *ab, const char *chars, int n_chars);
+void ab_free(struct append_buf *ab);
+
+#endif // APPEND_BUF_H

src/buffer.c

@@ -0,0 +1,149 @@
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "buffer.h"
+#include "kilo.h"
+#include "utils.h"
+
+static void buffer_free_rows(struct buffer *buffer);
+
+struct buffer *buffer_create(void) {
+    struct buffer *buf = malloc(sizeof(struct buffer));
+
+    buf->filename = NULL;
+    buf->rows = NULL;
+    buf->n_rows = 0;
+
+    return buf;
+}
+
+void buffer_read_file(struct buffer *buffer, const char *filename) {
+    if (buffer->filename)
+        free(buffer->filename);
+
+    if (buffer->rows)
+        buffer_free_rows(buffer);
+
+    size_t filename_len = strlen(filename);
+    buffer->filename = malloc(filename_len);
+    memcpy(buffer->filename, filename, filename_len);
+
+    FILE *file = fopen(filename, "r");
+    if (!file) die("fopen");
+
+    size_t line_buffer_size = 64;
+    char *line_buffer = malloc(line_buffer_size);
+
+    bool file_remaining = true;
+    while (file_remaining) {
+        char c;
+        int i;
+
+        for (i = 0; (c = getc(file)) != '\n' && c != EOF; i++) {
+            if (i >= (int) line_buffer_size)
+                line_buffer = realloc(line_buffer, line_buffer_size *= 2);
+
+            line_buffer[i] = c;
+        }
+
+        buffer_append_row(buffer, line_buffer, i);
+        file_remaining = (c != EOF);
+    }
+
+    free(line_buffer);
+    fclose(file);
+}
+
+void buffer_append_row(struct buffer *buffer, const char *chars, int n_chars) {
+    buffer->rows = realloc(buffer->rows, sizeof(struct erow) * (buffer->n_rows + 1));
+    struct erow *new_row = &buffer->rows[buffer->n_rows++];
+
+    new_row->chars = malloc(n_chars);
+    memcpy(new_row->chars, chars, n_chars);
+    new_row->n_chars = n_chars;
+
+    erow_update_rendering(new_row);
+}
+
+void buffer_free(struct buffer *buffer) {
+    free(buffer->filename);
+    buffer_free_rows(buffer);
+}
+
+static void buffer_free_rows(struct buffer *buffer) {
+    for (int i = 0; i < buffer->n_rows; i++) {
+        if (buffer->rows->chars) free(buffer->rows->chars);
+        if (buffer->rows->rchars) free(buffer->rows->rchars);
+    }
+}
+
+/*****************************************************************************/
+
+void erow_update_rendering(struct erow *erow) {
+    size_t line_buffer_size = 64;
+    char *line_buffer = malloc(line_buffer_size);
+    size_t n_rchars = 0;
+
+    for (int i = 0; i < erow->n_chars; i++) {
+        switch (erow->chars[i]) {
+            case '\t': {
+                int spaces = KILO_TAB_STOP - (n_rchars % KILO_TAB_STOP);
+                while (spaces--) {
+                    if (n_rchars >= line_buffer_size)
+                        line_buffer = realloc(line_buffer, 2*line_buffer_size);
+
+                    line_buffer[n_rchars++] = ' ';
+                }
+                break;
+            }
+            default:
+                if (n_rchars >= line_buffer_size)
+                    line_buffer = realloc(line_buffer, 2*line_buffer_size);
+
+                line_buffer[n_rchars++] = erow->chars[i];
+        }
+    }
+
+    if (erow->rchars)
+        free(erow->rchars);
+
+    erow->rchars = malloc(n_rchars);
+    erow->n_rchars = n_rchars;
+    memcpy(erow->rchars, line_buffer, n_rchars);
+
+    free(line_buffer);
+}
+
+int erow_cx_to_rx(struct erow *erow, int cx) {
+    int rx = 0;
+
+    if (erow == NULL)
+        return 0;
+
+    for (int i = 0; i < MIN(cx, erow->n_chars); i++) {
+        if (erow->chars[i] == '\t')
+            rx += KILO_TAB_STOP - (rx % KILO_TAB_STOP);
+        else rx++;
+    }
+
+    return rx;
+}
+
+int erow_rx_to_cx(struct erow *erow, int rx) {
+    int cx = 0, _rx = 0;
+
+    if (erow == NULL)
+        return 0;
+
+    while (_rx < rx && cx < erow->n_chars) {
+        if (erow->chars[cx] == '\t') {
+            _rx += KILO_TAB_STOP - (_rx % KILO_TAB_STOP);
+        } else _rx++;
+
+        cx++;
+    }
+
+    return (_rx >= rx ? cx : erow->n_chars);
+}

src/commands.c

@@ -0,0 +1,79 @@
+#include <stdbool.h>
+
+#include "commands.h"
+#include "kilo.h"
+#include "buffer.h"
+
+void editor_move_cursor(KEY key) {
+    struct erow *rows = E.current_buf->rows;
+    int n_rows = E.current_buf->n_rows;
+
+    struct erow *current_row = (E.cy < n_rows ? rows + E.cy : NULL);
+    int max_x = (current_row ? current_row->n_chars : 0);
+
+    switch (key) {
+        case ARROW_LEFT:
+            if (E.cx > 0) E.cx--;
+            else if (E.cy > 0) E.cx = rows[--E.cy].n_chars;
+            break;
+        case ARROW_DOWN:
+            if (E.cy < n_rows) E.cy++;
+            break;
+        case ARROW_UP:
+            if (E.cy > 0) E.cy--;
+            break;
+        case ARROW_RIGHT:
+            if (E.cx < max_x) E.cx++;
+            else if (E.cy < n_rows) {
+                E.cx = 0;
+                E.cy++;
+            }
+            break;
+
+        case HOME:
+            E.cx = 0;
+            break;
+        case END:
+            E.cx = max_x;
+            break;
+
+        case PG_UP:
+            if ((E.cy -= E.screenrows) < 0)
+                E.cy = 0;
+            break;
+        case PG_DOWN:
+            if ((E.cy += E.screenrows) > n_rows)
+                E.cy = n_rows;
+            break;
+    }
+
+    current_row = (E.cy < n_rows ? rows + E.cy : NULL);
+    max_x = (current_row ? current_row->n_chars : 0);
+
+    static int saved_rx = 0;
+    bool horizontal = (key == ARROW_LEFT || key == ARROW_RIGHT ||
+        key == HOME || key == END);
+    if (horizontal) saved_rx = erow_cx_to_rx(current_row, E.cx);
+    else E.cx = erow_rx_to_cx(current_row, saved_rx);
+
+    if (E.cx > max_x)
+        E.cx = max_x;
+
+    E.rx = erow_cx_to_rx(&E.current_buf->rows[E.cy], E.cx);
+
+    int max_row_off = E.cy;
+    if (E.row_off > max_row_off)
+        E.row_off = max_row_off;
+
+    int max_col_off = E.rx;
+    if (E.col_off > max_col_off)
+        E.col_off = max_col_off;
+
+    int min_row_off = E.cy - (E.screenrows - 1);
+    if (E.row_off < min_row_off)
+        E.row_off = min_row_off;
+
+    int min_col_off = E.rx - (E.screencols - 1);
+    if (E.col_off < min_col_off)
+        E.col_off = min_col_off;
+}

src/input.c

@@ -0,0 +1,27 @@
+#include <stdlib.h>
+
+#include "input.h"
+#include "terminal.h"
+#include "commands.h"
+
+void input_process_key(void) {
+    KEY c = terminal_read_key();
+
+    switch (c) {
+        case ARROW_LEFT:
+        case ARROW_DOWN:
+        case ARROW_UP:
+        case ARROW_RIGHT:
+        case HOME:
+        case END:
+        case PG_UP:
+        case PG_DOWN:
+            editor_move_cursor(c);
+            break;
+
+        case CTRL_KEY('Q'):
+            terminal_clear();
+            exit(0);
+            break;
+    }
+}

src/kilo.c

@@ -1,146 +1,53 @@
-#define _DEFAULT_SOURCE
-
-#define KILO_VERSION "0.0.1"
-#define KILO_TAB_STOP 4
-
 #include <stdarg.h>
+#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
 #include <unistd.h>
 
+#include "buffer.h"
 #include "kilo.h"
-#include "append_buf.h"
+#include "ui.h"
+#include "input.h"
 #include "terminal.h"
 
-#define CTRL_KEY(key) ((key) & 0x1f)
-
-#define MAX(a,b) (((a)>(b))?(a):(b))
-#define MIN(a,b) (((a)<(b))?(a):(b))
-
-/*****************************************************************************/
-
-struct EROW {
-    char *chars;
-    int n_chars;
-
-    char *rchars;
-    int n_rchars;
-};
+void editor_init(char *filename);
+void editor_set_message(const char *, ...);
 
 struct editor_state E;
 
-/*****************************************************************************/
-
-void editor_init(void);
-void editor_open(const char *);
-void editor_append_row(const char *, int);
-void editor_set_message(const char *, ...);
-
-void editor_redraw_screen(void);
-void editor_draw_rows(struct append_buf *);
-void editor_draw_statusbar(struct append_buf *);
-void editor_draw_messagebar(struct append_buf *);
-
-void editor_process_key(void);
-void editor_move_cursor(KEY);
-void editor_adjust_viewport(void);
-int editor_get_rx(int);
-int editor_get_cx(int);
-
-/*****************************************************************************/
-
 int main(int argc, char **argv) {
-    editor_init();
-
-    if (argc >= 2)
-        editor_open(argv[1]);
+    editor_init(argc >= 2 ? argv[1] : NULL);
 
     while (true) {
-        editor_redraw_screen();
-        editor_process_key();
+        ui_draw_screen();
+        input_process_key();
     }
 
     return 0;
 }
 
-/*****************************************************************************/
-
-void editor_init(void) {
+void editor_init(char *filename) {
     if (!isatty(STDIN_FILENO)) {
         printf("kilo only supports a terminal at standard in. Exiting.");
         exit(1);
     }
 
     if (terminal_enable_raw() == -1) die("term_enable_raw");
-    if (terminal_get_win_size(&E.screenrows, &E.screencols) == -1)
-        die("term_get_win_size");
 
-    E.filename = NULL;
-    E.cx = E.cy = 0;
-    E.rx = 0;
-    E.screenrows -= 2;
+    E.cx = E.cy = E.rx = 0;
     E.row_off = E.col_off = 0;
 
-    E.rows = NULL;
-    E.n_rows = 0;
+    if (terminal_get_win_size(&E.screenrows, &E.screencols) == -1)
+        die("term_get_win_size");
+    E.screenrows -= 2;
+
+    E.current_buf = buffer_create();
+    if (filename)
+        buffer_read_file(E.current_buf, filename);
 
     editor_set_message("Welcome to kilo. Press CTRL-Q to quit.");
 }
 
-void editor_open(const char *filename) {
-    free(E.filename);
-    E.filename = strdup(filename);
-
-    FILE *file = fopen(E.filename, "r");
-    if (!file) die("fopen");
-
-    char *line = NULL;
-    size_t linecap = 0;
-    int linelen = -1;
-
-    while ((linelen = getline(&line, &linecap, file)) != -1) {
-        while (linelen > 0 && (line[linelen-1] == '\n' || line[linelen-1] == '\r'))
-            linelen--;
-
-        editor_append_row(line, linelen);
-    }
-
-    free(line);
-    fclose(file);
-}
-
-void editor_append_row(const char *s, int len) {
-    E.rows = realloc(E.rows, sizeof(struct EROW) * (E.n_rows + 1));
-    struct EROW *new_row = E.rows + E.n_rows;
-
-    new_row->chars = malloc(len);
-    new_row->n_chars = len;
-
-    struct append_buf *sb = ab_init();
-    for (int i = 0; i < len; i++) {
-        new_row->chars[i] = s[i];
-
-        switch (s[i]) {
-            case TAB: {
-                int tabs = KILO_TAB_STOP - (sb->n_chars % KILO_TAB_STOP);
-                while (tabs--) ab_append(sb, " ", 1);
-                break;
-            }
-            default:
-                ab_append(sb, s+i, 1);
-        }
-    }
-
-    new_row->rchars = malloc(sb->n_chars);
-    new_row->n_rchars = sb->n_chars;
-    memcpy(new_row->rchars, sb->chars, sb->n_chars);
-
-    ab_free(sb);
-
-    E.n_rows++;
-}
-
 void editor_set_message(const char *fmt, ...) {
   va_list ap;
   va_start(ap, fmt);
@@ -149,217 +56,3 @@ void editor_set_message(const char *fmt, ...) {
 
   E.message_time = time(NULL);
 }
-
-
-void editor_redraw_screen(void) {
-    if (terminal_cursor_visibility(CURSOR_HIDDEN) == -1)
-        die("term_cursor_hidden");
-
-
-    struct append_buf *draw_buf = ab_init();
-
-    editor_draw_rows(draw_buf);
-    editor_draw_statusbar(draw_buf);
-    editor_draw_messagebar(draw_buf);
-
-    write(STDIN_FILENO, draw_buf->chars, draw_buf->n_chars);
-    ab_free(draw_buf);
-
-    int row_pos = E.cy - E.row_off + 1;
-    int col_pos = E.rx - E.col_off + 1;
-    if (terminal_set_cursor_pos(row_pos, col_pos) == -1)
-        die("term_set_cursor_pos");
-
-    if (terminal_cursor_visibility(CURSOR_SHOWN) == -1)
-        die("term_cursor_hidden");
-}
-
-void editor_draw_rows(struct append_buf *draw_buf) {
-    terminal_set_cursor_pos(1, 1);
-    for (int y = 0; y < E.screenrows; y++) {
-        bool in_file = y < E.n_rows - E.row_off;
-        bool no_file = E.n_rows == 0;
-
-        if (in_file) {
-            struct EROW curr_row = E.rows[y + E.row_off];
-            int max_len = MIN(curr_row.n_rchars - E.col_off, E.screencols);
-
-            ab_append(draw_buf, curr_row.rchars + E.col_off, MAX(max_len, 0));
-        } else if (no_file && y == E.screenrows / 2) {
-            char welcome[64];
-            int len = snprintf(welcome, sizeof(welcome),
-                               "Welcome to kilo! -- v%s", KILO_VERSION);
-
-            int padding = (E.screencols - len) / 2;
-            for (int i = 0; i < padding; i++)
-                ab_append(draw_buf, (i == 0 ? "~" : " "), 1);
-
-            ab_append(draw_buf, welcome, len);
-        } else ab_append(draw_buf, "~", 1);
-
-        ab_append(draw_buf, "\x1b[K\r\n", 5);
-    }
-}
-
-void editor_draw_statusbar(struct append_buf *draw_buf) {
-    char *status_buf = malloc(E.screencols), buf[256];
-    int len;
-
-    memset(status_buf, ' ', E.screencols);
-
-    ab_append(draw_buf, "\x1b[7m", 4);
-
-    len = sprintf(buf, "%s -- %d lines",
-                  (E.filename ? E.filename : "[NO NAME]"), E.n_rows);
-    memcpy(status_buf, buf, len);
-
-    len = sprintf(buf, "%d:%d", E.cy + 1, E.rx + 1);
-    memcpy(status_buf + E.screencols - len, buf, len);
-
-    ab_append(draw_buf, status_buf, E.screencols);
-    ab_append(draw_buf, "\x1b[m\r\n", 5);
-
-    free(status_buf);
-}
-void editor_draw_messagebar(struct append_buf *draw_buf) {
-    ab_append(draw_buf, "\x1b[K", 3);
-
-    int len = strlen(E.message);
-    if (len > E.screencols) len = E.screencols;
-
-    if (len && time(NULL) - E.message_time < 5)
-        ab_append(draw_buf, E.message, len);
-}
-
-
-void editor_process_key(void) {
-    KEY c = terminal_read_key();
-
-    switch (c) {
-        case ARROW_LEFT:
-        case ARROW_DOWN:
-        case ARROW_UP:
-        case ARROW_RIGHT:
-        case HOME:
-        case END:
-        case PG_UP:
-        case PG_DOWN:
-            editor_move_cursor(c);
-            break;
-
-        case CTRL_KEY('Q'):
-            terminal_clear();
-            exit(0);
-            break;
-    }
-}
-
-void editor_move_cursor(KEY key) {
-    int max_x = (E.cy < E.n_rows ? E.rows[E.cy].n_chars : 0);
-
-    switch (key) {
-        case ARROW_LEFT:
-            if (E.cx > 0) E.cx--;
-            else if (E.cy > 0) E.cx = E.rows[--E.cy].n_chars;
-            break;
-        case ARROW_DOWN:
-            if (E.cy < E.n_rows) E.cy++;
-            break;
-        case ARROW_UP:
-            if (E.cy > 0) E.cy--;
-            break;
-        case ARROW_RIGHT:
-            if (E.cx < max_x) E.cx++;
-            else if (E.cy < E.n_rows) {
-                E.cx = 0;
-                E.cy++;
-            }
-            break;
-
-        case HOME:
-            E.cx = 0;
-            break;
-        case END:
-            E.cx = max_x;
-            break;
-
-        case PG_UP:
-            if ((E.cy -= E.screenrows) < 0)
-                E.cy = 0;
-            break;
-        case PG_DOWN:
-            if ((E.cy += E.screenrows) > E.n_rows)
-                E.cy = E.n_rows;
-            break;
-    }
-
-    static int saved_rx = 0;
-    bool horizontal = (key == ARROW_LEFT || key == ARROW_RIGHT ||
-        key == HOME || key == END);
-    if (horizontal) saved_rx = editor_get_rx(E.cx);
-    else E.cx = editor_get_cx(saved_rx);
-
-    max_x = (E.cy < E.n_rows ? E.rows[E.cy].n_chars : 0);
-    if (E.cx > max_x)
-        E.cx = max_x;
-
-    E.rx = editor_get_rx(E.cx);
-    editor_adjust_viewport();
-}
-
-void editor_adjust_viewport(void) {
-    int max_row_off = E.cy;
-    if (E.row_off > max_row_off)
-        E.row_off = max_row_off;
-
-    int max_col_off = E.rx;
-    if (E.col_off > max_col_off)
-        E.col_off = max_col_off;
-
-    int min_row_off = E.cy - (E.screenrows - 1);
-    if (E.row_off < min_row_off)
-        E.row_off = min_row_off;
-
-    int min_col_off = E.rx - (E.screencols - 1);
-    if (E.col_off < min_col_off)
-        E.col_off = min_col_off;
-}
-
-int editor_get_rx(int cx) {
-    if (E.cy >= E.n_rows) return 0;
-    int rx = 0;
-
-    struct EROW *row = E.rows+E.cy;
-    for (int i = 0; i < MIN(cx, row->n_chars); i++) {
-        if (row->chars[i] == TAB)
-            rx += KILO_TAB_STOP - (rx % KILO_TAB_STOP);
-        else rx++;
-    }
-
-    return rx;
-}
-
-int editor_get_cx(int rx_target) {
-    if (E.cy >= E.n_rows) return 0;
-    int cx = 0, rx = 0;
-
-    struct EROW *row = E.rows+E.cy;
-    while (rx < rx_target && cx < row->n_chars) {
-        if (row->chars[cx] == TAB) {
-            rx += KILO_TAB_STOP - (rx % KILO_TAB_STOP);
-        } else rx++;
-
-        cx++;
-    }
-
-    return (rx >= rx_target ? cx : row->n_chars);
-}
-
-/*****************************************************************************/
-
-void die(const char *s) {
-    terminal_clear();
-
-    perror(s);
-    exit(1);
-}

src/terminal.c

@@ -5,6 +5,7 @@
 #include <unistd.h>
 
 #include "kilo.h"
+#include "utils.h"
 #include "terminal.h"
 
 ERRCODE terminal_enable_raw(void) {

src/ui.c

@@ -0,0 +1,95 @@
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "buffer.h"
+#include "kilo.h"
+#include "terminal.h"
+#include "ui.h"
+#include "utils.h"
+
+static void ui_draw_rows(struct append_buf *draw_buffer);
+static void ui_draw_statusbar(struct append_buf *draw_buffer);
+static void ui_draw_messagebar(struct append_buf *draw_buffer);
+
+void ui_draw_screen(void) {
+    if (terminal_cursor_visibility(CURSOR_HIDDEN) == -1)
+        die("term_cursor_hidden");
+
+    struct append_buf *draw_buf = ab_create();
+
+    ui_draw_rows(draw_buf);
+    ui_draw_statusbar(draw_buf);
+    ui_draw_messagebar(draw_buf);
+
+    write(STDIN_FILENO, draw_buf->chars, draw_buf->n_chars);
+    ab_free(draw_buf);
+
+    int row_pos = E.cy - E.row_off + 1;
+    int col_pos = E.rx - E.col_off + 1;
+    if (terminal_set_cursor_pos(row_pos, col_pos) == -1)
+        die("term_set_cursor_pos");
+
+    if (terminal_cursor_visibility(CURSOR_SHOWN) == -1)
+        die("term_cursor_hidden");
+}
+
+static void ui_draw_rows(struct append_buf *draw_buf) {
+    terminal_set_cursor_pos(1, 1);
+    for (int y = 0; y < E.screenrows; y++) {
+        bool in_file = (y < E.current_buf->n_rows - E.row_off);
+        bool no_file = (E.current_buf->n_rows == 0);
+
+        if (in_file) {
+            struct erow curr_row = E.current_buf->rows[y + E.row_off];
+            int max_len = MIN(curr_row.n_rchars - E.col_off, E.screencols);
+
+            ab_append(draw_buf, curr_row.rchars + E.col_off, MAX(max_len, 0));
+        } else if (no_file && y == E.screenrows / 2) {
+            char welcome[64];
+            int len = snprintf(welcome, sizeof(welcome),
+                               "Welcome to kilo! -- v%s", KILO_VERSION);
+
+            int padding = (E.screencols - len) / 2;
+            for (int i = 0; i < padding; i++)
+                ab_append(draw_buf, (i == 0 ? "~" : " "), 1);
+
+            ab_append(draw_buf, welcome, len);
+        } else ab_append(draw_buf, "~", 1);
+
+        ab_append(draw_buf, "\x1b[K\r\n", 5);
+    }
+}
+
+static void ui_draw_statusbar(struct append_buf *draw_buf) {
+    char *status_buf = malloc(E.screencols), buf[256];
+    int len;
+
+    memset(status_buf, ' ', E.screencols);
+
+    ab_append(draw_buf, "\x1b[7m", 4);
+
+    char *display = E.current_buf->filename ? E.current_buf->filename : "[NO NAME]";
+    len = sprintf(buf, "%s -- %d lines", display, E.current_buf->n_rows);
+    memcpy(status_buf, buf, len);
+
+    len = sprintf(buf, "%d:%d", E.cy + 1, E.rx + 1);
+    memcpy(status_buf + E.screencols - len, buf, len);
+
+    ab_append(draw_buf, status_buf, E.screencols);
+    ab_append(draw_buf, "\x1b[m\r\n", 5);
+
+    free(status_buf);
+}
+
+static void ui_draw_messagebar(struct append_buf *draw_buf) {
+    ab_append(draw_buf, "\x1b[K", 3);
+
+    int len = strlen(E.message);
+    if (len > E.screencols) len = E.screencols;
+
+    if (len && time(NULL) - E.message_time < 5)
+        ab_append(draw_buf, E.message, len);
+}

src/utils.c

@@ -1,9 +1,20 @@
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
-#include "append_buf.h"
+#include "utils.h"
+#include "terminal.h"
 
-struct append_buf *ab_init(void) {
+void die(const char *context) {
+    terminal_clear();
+
+    perror(context);
+    exit(1);
+}
+
+/*****************************************************************************/
+
+struct append_buf *ab_create(void) {
     size_t buf_size = sizeof(struct append_buf);
     struct append_buf *sb = (struct append_buf *) malloc(buf_size);