big buffer/buffer_view rework

A buffer is only the text and the corresponding operation. A buffer view
holds information about scroll, dot and mark positions. One way to think
about it is that a buffer is stateless whereas a buffer view is stateful.

1 files changed, 100 insertions, 0 deletions

diff --git a/src/dged/buffer_view.h b/src/dged/buffer_view.h
new file mode 100644
index 0000000..0002b95
--- /dev/null
+++ b/src/dged/buffer_view.h
@@ -0,0 +1,100 @@
+#ifndef _BUFFER_VIEW_H
+#define _BUFFER_VIEW_H
+
+#include <stddef.h>
+
+#include "location.h"
+
+struct buffer;
+
+/**
+ * A view of a buffer.
+ *
+ * This contains the mark and dot as well as the scroll position for a buffer.
+ */
+struct buffer_view {
+  /** Location of dot (cursor) */
+  struct location dot;
+
+  /** Location of mark (where a selection starts) */
+  struct location mark;
+
+  /** Current buffer scroll position */
+  struct location scroll;
+
+  /** Pointer to the actual buffer */
+  struct buffer *buffer;
+
+  /** Modeline buffer (may be NULL) */
+  struct modeline *modeline;
+
+  /** Current left fringe size */
+  uint32_t fringe_width;
+
+  /** Does the buffer show line numbers */
+  bool line_numbers;
+
+  /** True if the start of a selection has been set */
+  bool mark_set;
+};
+
+struct buffer_view buffer_view_create(struct buffer *buffer, bool modeline,
+                                      bool line_numbers);
+struct buffer_view buffer_view_clone(const struct buffer_view *view);
+void buffer_view_destroy(struct buffer_view *view);
+
+void buffer_view_add(struct buffer_view *view, uint8_t *txt, uint32_t nbytes);
+
+void buffer_view_goto_beginning(struct buffer_view *view);
+void buffer_view_goto_end(struct buffer_view *view);
+void buffer_view_goto(struct buffer_view *view, struct location to);
+void buffer_view_goto_end_of_line(struct buffer_view *view);
+void buffer_view_goto_beginning_of_line(struct buffer_view *view);
+
+void buffer_view_forward_char(struct buffer_view *view);
+void buffer_view_backward_char(struct buffer_view *view);
+void buffer_view_forward_word(struct buffer_view *view);
+void buffer_view_backward_word(struct buffer_view *view);
+void buffer_view_forward_line(struct buffer_view *view);
+void buffer_view_backward_line(struct buffer_view *view);
+void buffer_view_forward_nlines(struct buffer_view *view, uint32_t nlines);
+void buffer_view_backward_nlines(struct buffer_view *view, uint32_t nlines);
+
+void buffer_view_forward_delete_char(struct buffer_view *view);
+void buffer_view_backward_delete_char(struct buffer_view *view);
+void buffer_view_forward_delete_word(struct buffer_view *view);
+void buffer_view_backward_delete_word(struct buffer_view *view);
+
+void buffer_view_kill_line(struct buffer_view *view);
+
+void buffer_view_newline(struct buffer_view *view);
+void buffer_view_indent(struct buffer_view *view);
+
+void buffer_view_copy(struct buffer_view *view);
+void buffer_view_cut(struct buffer_view *view);
+void buffer_view_paste(struct buffer_view *view);
+void buffer_view_paste_older(struct buffer_view *view);
+
+void buffer_view_set_mark(struct buffer_view *view);
+void buffer_view_clear_mark(struct buffer_view *view);
+void buffer_view_set_mark_at(struct buffer_view *view, struct location mark);
+
+struct location buffer_view_dot_to_relative(struct buffer_view *view);
+
+void buffer_view_undo(struct buffer_view *view);
+
+struct buffer_view_update_params {
+  struct command_list *commands;
+  void *(*frame_alloc)(size_t);
+  uint32_t window_id;
+  int64_t frame_time;
+  uint32_t width;
+  uint32_t height;
+  uint32_t window_x;
+  uint32_t window_y;
+};
+
+void buffer_view_update(struct buffer_view *view,
+                        struct buffer_view_update_params *params);
+
+#endif