From 798f5895a0d54a9848e29bb70ddc4a8ef3b6fc6f Mon Sep 17 00:00:00 2001
From: Aaron Fischer <aaron.fischer@marbis.net>
Date: Mon, 8 Oct 2018 14:13:00 +0200
Subject: [PATCH] Add the remaining editor features

---
 kilo.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 72 insertions(+), 7 deletions(-)

diff --git a/kilo.c b/kilo.c
index 5c37762..bee0c25 100644
--- a/kilo.c
+++ b/kilo.c
@@ -224,10 +224,12 @@ void editorUpdateRow(erow *row) {
   row->rsize = idx;
 }
 
-void editorAppendRow(char *s, size_t len) {
-  E.row = realloc(E.row, sizeof(erow) * (E.numrows +1));
+void editorInsertRow(int at, char *s, size_t len) {
+  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);
@@ -241,6 +243,19 @@ void editorAppendRow(char *s, size_t len) {
   E.dirty++;
 }
 
+void editorFreeRow(erow *row) {
+  free(row->render);
+  free(row->chars);
+}
+
+void editorDelRow(int at) {
+  if (at < 0 || at >= E.numrows) return;
+  editorFreeRow(&E.row[at]);
+  memmove(&E.row[at], &E.row[at + 1], sizeof(erow) * (E.numrows - at -1));
+  E.numrows--;
+  E.dirty++;
+}
+
 void editorRowInsertChar(erow *row, int at, int c) {
   if (at < 0 || at > row->size) at = row->size;
   row->chars = realloc(row->chars, row->size + 2);
@@ -251,17 +266,66 @@ void editorRowInsertChar(erow *row, int at, int c) {
   E.dirty++;
 }
 
+void editorRowAppendString(erow *row, char *s, size_t len) {
+  row->chars = realloc(row->chars, row->size + len + 1);
+  memcpy(&row->chars[row->size], s, len);
+  row->size += len;
+  row->chars[row->size] = '\0';
+  editorUpdateRow(row);
+  E.dirty++;
+}
+
+void editorRowDelChar(erow *row, int at) {
+  if (at < 0 || at >= row->size) return;
+  memmove(&row->chars[at], &row->chars[at + 1], row->size - at);
+  row->size--;
+  editorUpdateRow(row);
+  E.dirty++;
+}
+
 
 /*** editor operations ***/
 
 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) return;
+  if (E.cx == 0 && E.cy == 0) return;
+
+  erow *row = &E.row[E.cy];
+  if (E.cx > 0) {
+    editorRowDelChar(row, E.cx - 1);
+    E.cx--;
+  } else {
+    E.cx = E.row[E.cy - 1].size;
+    editorRowAppendString(&E.row[E.cy - 1], row->chars, row->size);
+    editorDelRow(E.cy);
+    E.cy--;
+  }
+}
+
 /*** file i/o ***/
 
 char *editorRowsToString(int *buflen) {
@@ -298,7 +362,7 @@ void editorOpen(char *filename) {
     while (linelen > 0 && (line[linelen - 1] == '\n' ||
                            line[linelen - 1] == '\r'))
       linelen--;
-    editorAppendRow(line, linelen);
+    editorInsertRow(E.numrows, line, linelen);
   }
   free(line);
   fclose(fp);
@@ -514,7 +578,7 @@ void editorProcessKeypress() {
 
   switch (c) {
     case '\r':
-      /* TODO */
+      editorInsertNewLine();
       break;
 
     case CTRL_KEY('q'):
@@ -546,7 +610,8 @@ void editorProcessKeypress() {
     case BACKSPACE:
     case CTRL_KEY('h'):
     case DEL_KEY:
-      /* TODO */
+      if (c == DEL_KEY) editorMoveCursor(ARROW_RIGHT);
+      editorDelChar();
       break;
 
     case PAGE_UP: