Add proper undo to buffer reloading

It now creates an undo entry for the whole file.

4 files changed, 84 insertions, 3 deletions

diff --git a/src/dged/buffer.c b/src/dged/buffer.c
index fed8f87..c3f5655 100644
--- a/src/dged/buffer.c
+++ b/src/dged/buffer.c
@@ -234,8 +234,6 @@ static void buffer_read_from_file(struct buffer *b) {
     free(fullname);
     return;
   }
-
-  undo_push_boundary(&b->undo, (struct undo_boundary){.save_point = true});
 }
 
 static void write_line_lf(struct text_chunk *chunk, void *userdata) {
@@ -388,6 +386,7 @@ struct buffer buffer_from_file(const char *path) {
   char *full_path = to_abspath(path);
   struct buffer b = create_internal(basename((char *)path), full_path);
   buffer_read_from_file(&b);
+  undo_push_boundary(&b.undo, (struct undo_boundary){.save_point = true});
 
   dispatch_hook(&g_create_hooks, struct create_hook, &b);
 
@@ -470,6 +469,8 @@ void buffer_set_filename(struct buffer *buffer, const char *filename) {
   buffer->modified = true;
 }
 
+static void *text_alloc(size_t sz) { return calloc(sz, 1); }
+
 void buffer_reload(struct buffer *buffer) {
   if (buffer->filename == NULL) {
     return;
@@ -484,8 +485,26 @@ void buffer_reload(struct buffer *buffer) {
 
   if (sb.st_mtim.tv_sec != buffer->last_write.tv_sec ||
       sb.st_mtim.tv_nsec != buffer->last_write.tv_nsec) {
+
+    undo_push_boundary(&buffer->undo,
+                       (struct undo_boundary){.save_point = false});
+
+    struct text_chunk txt = buffer_text(buffer);
+    undo_push_delete(
+        &buffer->undo,
+        (struct undo_delete){.data = txt.text,
+                             .nbytes = txt.nbytes,
+                             .pos = ((struct position){.col = 0, .row = 0})});
     text_clear(buffer->text);
+
     buffer_read_from_file(buffer);
+    undo_push_add(
+        &buffer->undo,
+        (struct undo_add){.begin = (struct position){.col = 0, .row = 0},
+                          .end = (struct position){
+                              .col = 0, .row = buffer_num_lines(buffer)}});
+    undo_push_boundary(&buffer->undo,
+                       (struct undo_boundary){.save_point = true});
     dispatch_hook(&buffer->hooks->reload_hooks, struct reload_hook, buffer);
   }
 }
@@ -1081,6 +1100,10 @@ struct text_chunk buffer_line(struct buffer *buffer, uint32_t line) {
   return text_get_line(buffer->text, line);
 }
 
+struct text_chunk buffer_text(struct buffer *buffer) {
+  return text_get(buffer->text, text_alloc);
+}
+
 struct text_chunk buffer_region(struct buffer *buffer, struct region region) {
   struct location begin_bytes =
       buffer_location_to_byte_coords(buffer, region.begin);
diff --git a/src/dged/buffer.h b/src/dged/buffer.h
index 25cc42b..640150a 100644
--- a/src/dged/buffer.h
+++ b/src/dged/buffer.h
@@ -435,6 +435,15 @@ struct text_chunk buffer_line(struct buffer *buffer, uint32_t line);
 struct text_chunk buffer_region(struct buffer *buffer, struct region region);
 
 /**
+ * Get all text in the buffer.
+ *
+ * @param buffer The buffer to get text from.
+ *
+ * @returns A text chunk describing the full buffer
+ */
+struct text_chunk buffer_text(struct buffer *buffer);
+
+/**
  * Add a text property to a region of the buffer.
  *
  * @param buffer The buffer to add a text property to.
diff --git a/src/dged/text.c b/src/dged/text.c
index 59290ca..f517ed4 100644
--- a/src/dged/text.c
+++ b/src/dged/text.c
@@ -6,7 +6,6 @@
 #include <string.h>
 
 #include "display.h"
-#include "signal.h"
 #include "utf8.h"
 #include "vec.h"
 
@@ -167,6 +166,15 @@ uint32_t text_line_size(const struct text *text, uint32_t lineidx) {
 
 uint32_t text_num_lines(const struct text *text) { return text->nlines; }
 
+size_t text_size(const struct text *text) {
+  size_t total = 0;
+  for (uint64_t linei = 0; linei < text->nlines; ++linei) {
+    total += text->lines[linei].nbytes;
+  }
+
+  return total;
+}
+
 static void split_line(struct text *text, uint32_t offset, uint32_t lineidx,
                        uint32_t newlineidx) {
   struct line *line = &text->lines[lineidx];
@@ -486,6 +494,44 @@ struct text_chunk text_get_region(struct text *text, uint32_t start_line,
   };
 }
 
+struct copy_chunk_params {
+  enum line_endings line_endings;
+  struct text_chunk *target_chunk;
+};
+
+static void copy_chunk(struct text_chunk *src, void *userdata) {
+  struct copy_chunk_params *params = (struct copy_chunk_params *)userdata;
+  struct text_chunk *target = params->target_chunk;
+
+  memcpy(target->text + target->nbytes, src->text, src->nbytes);
+  target->nbytes += src->nbytes;
+  if (params->line_endings == LineEnding_CRLF) {
+    target->text[target->nbytes] = '\r';
+    ++target->nbytes;
+  }
+
+  target->text[target->nbytes] = '\n';
+  ++target->nbytes;
+}
+
+struct text_chunk text_get(struct text *text, void *(*alloc)(size_t size)) {
+  size_t needed = text_size(text);
+  size_t line_end_bytes = 1;
+  if (text->line_ends == LineEnding_CRLF) {
+    line_end_bytes = 2;
+  }
+  needed += text_num_lines(text) * line_end_bytes;
+
+  struct text_chunk ret = {0};
+  ret.text = alloc(needed);
+  ret.allocated = true;
+
+  struct copy_chunk_params params = {.target_chunk = &ret,
+                                     .line_endings = text->line_ends};
+  text_for_each_chunk(text, copy_chunk, &params);
+  return ret;
+}
+
 static property_vec *find_property_layer(struct text *text, layer_id layer) {
   if (layer == PropertyLayer_Default) {
     return &text->properties;
diff --git a/src/dged/text.h b/src/dged/text.h
index 108ded8..1ad6dbc 100644
--- a/src/dged/text.h
+++ b/src/dged/text.h
@@ -41,6 +41,7 @@ void text_delete(struct text *text, uint32_t start_line, uint32_t start_offset,
 
 enum line_endings text_get_line_ending(const struct text *);
 
+size_t text_size(const struct text *text);
 uint32_t text_num_lines(const struct text *text);
 uint32_t text_line_size(const struct text *text, uint32_t lineidx);
 struct utf8_codepoint_iterator
@@ -59,6 +60,8 @@ struct text_chunk text_get_region(struct text *text, uint32_t start_line,
                                   uint32_t start_offset, uint32_t end_line,
                                   uint32_t end_offset);
 
+struct text_chunk text_get(struct text *text, void *(*alloc)(size_t size));
+
 enum text_property_type {
   TextProperty_Colors,
   TextProperty_Data,