Status bar / editing / saving file

src/output.c

@@ -1,4 +1,8 @@
 #include "../include/output.h"
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
 
 void editorDrawRows(struct editorConfig *E, struct abuf *ab) {
   int y;
@@ -30,18 +34,77 @@ void editorDrawRows(struct editorConfig *E, struct abuf *ab) {
         abAppend(ab, "~", 1);
       }
     } else {
-      len = E->row[file_row].size > E->screencols ? E->screencols
-                                                  : E->row[y].size;
-      abAppend(ab, E->row[file_row].chars, len);
+      len = E->row[file_row].rsize - E->col_offset;
+      if (len < 0)
+        len = 0;
+      if (len > E->screencols)
+        len = E->screencols;
+      abAppend(ab, &E->row[file_row].render[E->col_offset], len);
     }
     abAppend(ab, ERASE_END_LINE, 3);
-    if (y < E->screenrows - 1) {
-      abAppend(ab, "\r\n", 2);
+    abAppend(ab, "\r\n", 2);
+  }
+}
+
+void editorScroll(struct editorConfig *E) {
+  E->rx = E->cursor_x;
+  if (E->cursor_y < E->numrows) {
+    E->rx = editorRowCxToRx(&E->row[E->cursor_y], E->cursor_x);
+  }
+
+  if (E->cursor_y < E->row_offset) {
+    E->row_offset = E->cursor_y;
+  }
+  if (E->cursor_y >= E->row_offset + E->screenrows) {
+    E->row_offset = E->cursor_y - E->screenrows + 1;
+  }
+  if (E->rx < E->col_offset) {
+    E->col_offset = E->rx;
+  }
+  if (E->rx >= E->col_offset + E->screencols) {
+    E->col_offset = E->rx - E->screencols + 1;
+  }
+}
+
+void editorDrawStatusBar(struct editorConfig *E, struct abuf *ab) {
+  int len, render_len;
+  char status[80], render_status[80];
+
+  abAppend(ab, "\x1b[7m", 4); // inverting colors
+  len = snprintf(status, sizeof(status), "%.20s - %d lines",
+                 E->filename ? E->filename : "[No Name]", E->numrows);
+  render_len = snprintf(render_status, sizeof(render_status), "%d/%d",
+                        E->cursor_y + 1, E->numrows);
+  if (len > E->screencols) {
+    len = E->screencols;
+  }
+  abAppend(ab, status, len);
+  while (len < E->screencols) {
+    if (E->screencols - len == render_len) {
+      abAppend(ab, render_status, render_len);
+      break;
+    } else {
+      abAppend(ab, " ", 1);
+      ++len;
     }
   }
+  abAppend(ab, "\x1b[m", 3); // normal text mode
+  abAppend(ab, "\r\n", 2);
+}
+
+void editorDrawMessageBar(struct editorConfig *E, struct abuf *ab) {
+  int msg_len = strlen(E->status_msg);
+  abAppend(ab, ERASE_END_LINE, 3);
+  if (msg_len > E->screencols) {
+    msg_len = E->screencols;
+  }
+  if (msg_len && time(NULL) - E->status_msg_time < 5) {
+    abAppend(ab, E->status_msg, msg_len);
+  }
 }
 
 void editorRefreshScreen(struct editorConfig *E) {
+  editorScroll(E);
   struct abuf ab = ABUF_INIT;
   char buf[32];
 
@@ -49,8 +112,11 @@ void editorRefreshScreen(struct editorConfig *E) {
   abAppend(&ab, CURSOR_TOP_LEFT, 3);
 
   editorDrawRows(E, &ab);
+  editorDrawStatusBar(E, &ab);
+  editorDrawMessageBar(E, &ab);
 
-  snprintf(buf, sizeof(buf), "\x1b[%d;%dH", E->cursor_y + 1, E->cursor_x + 1);
+  snprintf(buf, sizeof(buf), "\x1b[%d;%dH", (E->cursor_y - E->row_offset) + 1,
+           (E->rx - E->col_offset) + 1);
   abAppend(&ab, buf, strlen(buf));
 
   abAppend(&ab, SHOW_CURSOR, 6);
@@ -58,3 +124,11 @@ void editorRefreshScreen(struct editorConfig *E) {
   write(STDOUT_FILENO, ab.b, ab.len);
   abFree(&ab);
 }
+
+void editorSetStatusMessage(struct editorConfig *E, const char *fmt, ...) {
+  va_list ap;
+  va_start(ap, fmt);
+  vsnprintf(E->status_msg, sizeof(E->status_msg), fmt, ap);
+  va_end(ap);
+  E->status_msg_time = time(NULL);
+}