Chapter 5: Start

kilo.c

@@ -7,16 +7,19 @@
 #include <ctype.h>
 #include <errno.h>
 #include <stdio.h>
+#include <stdarg.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/ioctl.h>
 #include <sys/types.h>
 #include <unistd.h>
+#include <time.h>
 #include <termios.h>
 
 /*** defines ***/
 
 #define KILO_VERSION "0.0.1"
+#define KILO_TAB_STOP 4
 
 #define CTRL_KEY(k) ((k) & 0x1f)
 
@@ -37,18 +40,24 @@ enum editorKey
 
 typedef struct erow {
   int size;
+  int rsize;
   char *chars;
+  char *render;
 } erow;
 
 struct editorConfig
 {
   int cx, cy;
+  int rx;
   int rowoff; // Row offset
   int coloff; // Col offset
   int screenrows;
   int screencols;
   int numrows;
   erow *row;
+  char *filename;
+  char statusmsg[80];
+  time_t statusmsg_time;
   struct termios orig_termios;
 };
 
@@ -207,6 +216,41 @@ int getWindowSize(int *rows, int *cols)
 
 /*** row operations ***/
 
+int editorRowCxToRx(erow *row, int cx) {
+  int rx = 0;
+  int j;
+  for (j = 0; j < cx; j++) {
+    if (row->chars[j] == '\t')
+      rx =+ (KILO_TAB_STOP - 1) - (rx % KILO_TAB_STOP);
+    rx++;
+  }
+  return rx;
+}
+
+void editorUpdateRow(erow *row) {
+  int tabs = 0;
+  int j;
+  for (j = 0; j < row->size; j++)
+    if (row->chars[j] == '\t') tabs++;
+
+  free(row->render);
+  row->render = malloc(row->size + tabs*(KILO_TAB_STOP - 1) + 1);
+
+
+
+  int idx = 0;
+  for (j = 0; j < row->size; j++) {
+    if (row->chars[j] == '\t') {
+      row->render[idx++] = ' ';
+      while (idx % KILO_TAB_STOP != 0) row->render[idx++] = ' ';
+    } else {
+      row->render[idx++] = row->chars[j];
+    }
+  }
+  row->render[idx] = '\0';
+  row->rsize = idx;
+}
+
 void editorAppendRow(char *s, size_t len) {
   E.row = realloc(E.row, sizeof(erow) * (E.numrows + 1));
 
@@ -215,12 +259,20 @@ void editorAppendRow(char *s, size_t len) {
   E.row[at].chars = malloc(len + 1);
   memcpy(E.row[at].chars, s, len);
   E.row[at].chars[len] = '\0';
+
+  E.row[at].rsize = 0;
+  E.row[at].render = NULL;
+  editorUpdateRow(&E.row[at]);
+
   E.numrows++;
 }
 
 /*** file i/o ***/
 
 void editorOpen(char *filename) {
+  free(E.filename);
+  E.filename = strdup(filename);
+
   FILE *fp = fopen(filename, "r");
   if (!fp) die("fopen");
 
@@ -268,17 +320,24 @@ void abFree(struct abuf *ab)
 /*** output ***/
 
 void editorScroll() {
+  E.rx = 0;
+
+  if (E.cy < E.numrows) {
+    E.rx = editorRowCxToRx(&E.row[E.cy], E.cx);
+  }
+
+
   if (E.cy < E.rowoff) {
     E.rowoff = E.cy;
   }
   if (E.cy >= E.rowoff + E.screenrows) {
     E.rowoff = E.cy - E.screenrows + 1;
   }
-  if (E.cx < E.coloff) {
+  if (E.rx < E.coloff) {
-    E.coloff = E.cx;
+    E.coloff = E.rx;
   }
-  if (E.cx >= E.coloff + E.screencols) {
+  if (E.rx >= E.coloff + E.screencols) {
-    E.coloff = E.cx - E.screencols + 1;
+    E.coloff = E.rx - E.screencols + 1;
   }
 }
 
@@ -312,17 +371,44 @@ void editorDrawRows(struct abuf *ab)
       }
 
     } else {
-      int len = E.row[filerow].size - E.coloff;
+      int len = E.row[filerow].rsize - E.coloff;
       if (len < 0) len = 0;
       if (len > E.screencols) len = E.screencols;
-      abAppend(ab, &E.row[filerow].chars[E.coloff], len);
+      abAppend(ab, &E.row[filerow].render[E.coloff], len);
     }
     abAppend(ab, "\x1b[K", 3);
-    if (y < E.screenrows - 1)
-    {
     abAppend(ab, "\r\n", 2);
   }
+}
+
+void editorDrawStatusBar(struct abuf *ab) {
+  abAppend(ab, "\x1b[7m", 4);
+  char status[80], rstatus[80];
+  int len = snprintf(status, sizeof(status), "%.20s - %d lines",
+                     E.filename ? E.filename : "[No Name]", E.numrows);
+  int rlen = snprintf(rstatus, sizeof(rstatus), "%d/%d",
+                      E.cy + 1, E.numrows);
+  if (len > E.screencols) len = E.screencols;
+  abAppend(ab, status, len);
+  while (len < E.screencols) {
+    if (E.screencols - len == rlen) {
+      abAppend(ab, rstatus, rlen);
+      break;
+    } else {
+      abAppend(ab, " ", 1);
+      len++;
     }
+  }
+  abAppend(ab, "\x1b[m", 3);
+  abAppend(ab, "\r\n", 2);
+}
+
+void editorDrawMessageBar(struct abuf *ab) {
+  abAppend(ab, "\x1b[K", 3);
+  int msglen = strlen(E.statusmsg);
+  if (msglen > E.screencols) msglen = E.screencols;
+  if (msglen && time(NULL) - E.statusmsg_time < 5)
+    abAppend(ab, E.statusmsg, msglen);
 }
 
 void editorRefreshScreen()
@@ -334,9 +420,11 @@ void editorRefreshScreen()
   abAppend(&ab, "\x1b[H", 3);
 
   editorDrawRows(&ab);
+  editorDrawStatusBar(&ab);
+  editorDrawMessageBar(&ab);
 
   char buf[32];
-  snprintf(buf, sizeof(buf), "\x1b[%d;%dH", (E.cy - E.rowoff) + 1, (E.cx - E.coloff) + 1);
+  snprintf(buf, sizeof(buf), "\x1b[%d;%dH", (E.cy - E.rowoff) + 1, (E.rx - E.coloff) + 1);
   abAppend(&ab, buf, strlen(buf));
 
   abAppend(&ab, "\x1b[?25h", 6);
@@ -344,6 +432,14 @@ void editorRefreshScreen()
   abFree(&ab);
 }
 
+void editorSetStatusMessage(const char *fmt, ...) {
+  va_list ap;
+  va_start(ap, fmt);
+  vsnprintf(E.statusmsg, sizeof(E.statusmsg), fmt, ap);
+  va_end(ap);
+  E.statusmsg_time = time(NULL);
+}
+
 /*** input ***/
 
 void editorMoveCursor(int key)
@@ -408,14 +504,18 @@ void editorProcessKeypress()
     E.cx = 0;
     break;
   case END_KEY:
-    E.cx = E.screencols - 1;
+    if (E.cy < E.numrows)
+      E.cx = E.row[E.cy].size;
     break;
   case PAGE_UP:
   case PAGE_DOWN:
   {
-    int times = E.screenrows;
+    if (c == PAGE_UP) {
-    while (times--)
+          E.cy = E.rowoff;
-      editorMoveCursor(c == PAGE_UP ? ARROW_UP : ARROW_DOWN);
+    } else {
+      E.cy = E.rowoff + E.screenrows - 1;
+      if (E.cy > E.numrows) E.cy = E.numrows;
+    } 
   }
   break;
 
@@ -434,13 +534,18 @@ void initEditor()
 {
   E.cx = 0;
   E.cy = 0;
+  E.rx = 0;
   E.rowoff = 0;
   E.coloff = 0;
   E.numrows = 0;
   E.row = NULL;
+  E.filename = NULL;
+  E.statusmsg[0] = '\0';
+  E.statusmsg_time = 0;
 
   if (getWindowSize(&E.screenrows, &E.screencols) == -1)
     die("getWindowSize");
+  E.screenrows -= 2;
 }
 
 int main(int argc, char *argv[])
@@ -451,6 +556,8 @@ int main(int argc, char *argv[])
     editorOpen(argv[1]);
   }
   
+  editorSetStatusMessage("HELP Ctrl-Q = Quit");
+
   while (1)
   {
     editorRefreshScreen();