pretty much working, need to fix horizontal scrolling & file saving

final/editor.c

@@ -23,6 +23,8 @@ void add_toolbar(Editor* self) {
     addstr(mode);
 }
 
+#define min(x, y) ((x) < (y) ? (x) : (y))
+
 void refresh_buffer(Editor* self) {
 
     move(0, 0);
@@ -36,24 +38,62 @@ void refresh_buffer(Editor* self) {
     for (size_t i = self->y_offset; i < self->lines && i < self->y_offset + max_y; i++) {
     // for (size_t i = 0; i < self->lines; i++) {
         // adding the line number
-        char line_no[5];
+        char line_no[6];
         snprintf(line_no, 5, "%-5d", i + 1);
         // adding the line of text to the buffer
         addstr(line_no);
         addch(' ');
-        addstr(to_chars(&self->buffer[i]));
+
+        String_t line_segment = str_slice(
+            &self->buffer[i],
+            self->x_offset,
+            min(str_len(&self->buffer[i]), self->x_offset + max_x - 5)
+        );
+
+        addstr(to_chars(&line_segment));
+        str_dealloc(&line_segment);
+
         addstr("\n");   
     }    
 
     add_toolbar(self);
 
-    move(self->buffer_line, self->buffer_col + 5);
+    move(self->buffer_line - self->y_offset, self->buffer_col - self->x_offset + 5);
 }
 
 void move_cursor_on_screen(Editor* editor, int x, int y) {
     int newx = x + 5; // account for the line number
 
-    move(y, newx);
+    int max_x, max_y;
+    getmaxyx(stdscr, max_y, max_x);
+
+    bool flag = false;
+    
+    while (newx + 3 > max_x + editor->x_offset) {
+        editor->x_offset += 1;
+        flag = true;
+    }
+
+    while (newx - 3 < editor->x_offset) {
+        editor->x_offset -= 1;
+        flag = true;
+    }
+
+    while (y + 3 > max_y + editor->y_offset) {
+        editor->y_offset += 1;
+        flag = true;
+    }   
+
+    while (y - 3 < editor->y_offset) {
+        editor->y_offset -= 1;
+        flag = true;
+    }   
+
+    if (flag) {
+        refresh_buffer(editor);
+    }
+
+    move(y - editor->y_offset, newx - editor->x_offset);
 }
 
 void switch_mode(Editor* self) {
@@ -63,12 +103,15 @@ void switch_mode(Editor* self) {
 
 void newline(Editor* self) {
     move(self->buffer_line, 0);
-    char line_no[5];
+    char line_no[6];
     snprintf(line_no, 5, "%-5d", self->buffer_line + 1);
+
+    fprintf(stderr, "ln: %d, col: %d", self->buffer_line, self->buffer_col);
+
     // adding the line of text to the buffer
     addstr(line_no);
     addch(' ');
-    move(self->buffer_line, self->buffer_col + 5);
+    move_cursor_on_screen(self, self->buffer_col, self->buffer_line);
 }
 
 Editor editor_from(String_t input_string) {
@@ -120,6 +163,7 @@ void move_cursor(Editor* self, int x, int y) {
         // moving the cursor left or right in any other case
         self->buffer_col += x;
     }    
+    fprintf(stderr, "ln: %d, col: %d xoff: %d yoff: %d\n", self->buffer_line, self->buffer_col, self->x_offset, self->y_offset);
     move_cursor_on_screen(self, self->buffer_col, self->buffer_line);
 }