From 9248b9d56057bcb7b13f7ececeb4233ac7ccfbd0 Mon Sep 17 00:00:00 2001
From: Timothy Warren <twarren@nabancard.com>
Date: Tue, 20 Aug 2019 12:02:40 -0400
Subject: [PATCH] Insert new lines

---
 kilo.c | 36 ++++++++++++++++++++++++++++++------
 1 file changed, 30 insertions(+), 6 deletions(-)

diff --git a/kilo.c b/kilo.c
index 9fedc36..6a0ecac 100644
--- a/kilo.c
+++ b/kilo.c
@@ -303,11 +303,16 @@ void editorUpdateRow(erow *row)
 	row->rsize = idx;
 }
 
-void editorAppendRow(char *s, size_t len)
+void editorInsertRow(int at, char *s, size_t len)
 {
-	E.row = realloc(E.row, sizeof(erow) * (E.numrows + 1));
+	if (at < 0 || at > E.numrows)
+	{
+		return;
+	}
+
+	E.row = realloc(E.row, sizeof(erow) * (E.numrows + 1));
+	memmove(&E.row[at + 1], &E.row[at], sizeof(erow) * (E.numrows - at));
 
-	int at = E.numrows;
 	E.row[at].size = len;
 	E.row[at].chars = malloc(len + 1);
 	memcpy(E.row[at].chars, s, len);
@@ -383,12 +388,31 @@ void editorInsertChar(int c)
 {
 	if (E.cy == E.numrows)
 	{
-		editorAppendRow("", 0);
+		editorInsertRow(E.numrows, "", 0);
 	}
 	editorRowInsertChar(&E.row[E.cy], E.cx, c);
 	E.cx++;
 }
 
+void editorInsertNewline()
+{
+	if (E.cx == 0)
+	{
+		editorInsertRow(E.cy, "", 0);
+	}
+	else
+	{
+		erow *row = &E.row[E.cy];
+		editorInsertRow(E.cy + 1, &row->chars[E.cx], row->size - E.cx);
+		row = &E.row[E.cy];
+		row->size = E.cx;
+		row->chars[row->size] = '\0';
+		editorUpdateRow(row);
+	}
+	E.cy++;
+	E.cx = 0;
+}
+
 void editorDelChar()
 {
 	if (E.cy == E.numrows)
@@ -463,7 +487,7 @@ void editorOpen(char *filename)
 		{
 			linelen--;
 		}
-		editorAppendRow(line, linelen);
+		editorInsertRow(E.numrows, line, linelen);
 	}
 
 	free(line);
@@ -766,7 +790,7 @@ void editorProcessKeypress()
 	switch (c)
 	{
 		case '\r':
-			/* TODO */
+			editorInsertNewline();
 		break;
 
 		case CTRL_KEY('q'):