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-rw-r--r--buffer.c147
1 files changed, 107 insertions, 40 deletions
diff --git a/buffer.c b/buffer.c
index 2338427..cfc8880 100644
--- a/buffer.c
+++ b/buffer.c
@@ -17,6 +17,21 @@ typedef struct {
char32_t *str;
} Line;
+typedef enum {
+ BUFFER_EDIT_DELETE_LINE, // line = line #, prev_str = contents of line before it was deleted
+ BUFFER_EDIT_INSERT_LINE, // line = line #
+ BUFFER_EDIT_CHANGE_LINE // line = line #, prev_str = contents of line before change
+} BufferEditType;
+
+typedef struct BufferEdit {
+ u8 type;
+ bool join_with_next;
+ u32 prev_str_len;
+ u32 line;
+ struct BufferEdit *next;
+ char32_t prev_str[];
+} BufferEdit;
+
typedef struct {
char const *filename;
double scroll_x, scroll_y; // number of characters scrolled in the x/y direction
@@ -28,8 +43,12 @@ typedef struct {
u32 lines_capacity;
Line *lines;
char error[128];
+ BufferEdit *undo_history;
+ BufferEdit *redo_history;
} TextBuffer;
+
+
// for debugging
#if DEBUG
static void buffer_pos_check_valid(TextBuffer *buffer, BufferPos p) {
@@ -48,7 +67,6 @@ static void buffer_check_valid(TextBuffer *buffer) {
}
#endif
-
void buffer_create(TextBuffer *buffer, Font *font) {
util_zero_memory(buffer, sizeof *buffer);
buffer->font = font;
@@ -73,6 +91,32 @@ static void buffer_out_of_mem(TextBuffer *buffer) {
buffer_seterr(buffer, "Out of memory.");
}
+static void buffer_append_edit(TextBuffer *buffer, BufferEdit *edit) {
+ edit->next = buffer->undo_history;
+ buffer->undo_history = edit;
+}
+
+static void *buffer_calloc(TextBuffer *buffer, size_t n, size_t size) {
+ void *ret = calloc(n, size);
+ if (!ret) buffer_out_of_mem(buffer);
+ return ret;
+}
+
+static void *buffer_realloc(TextBuffer *buffer, void *p, size_t new_size) {
+ void *ret = realloc(p, new_size);
+ if (!ret) buffer_out_of_mem(buffer);
+ return ret;
+}
+
+static WarnUnusedResult BufferEdit *buffer_edit_delete_line(TextBuffer *buffer, u32 line, bool join_with_next) {
+ BufferEdit *e = buffer_calloc(buffer, 1, sizeof *e);
+ if (e) {
+ e->type = BUFFER_EDIT_DELETE_LINE;
+ e->line = line;
+ e->join_with_next = join_with_next;
+ }
+ return e;
+}
// grow capacity of line to at least minimum_capacity
// returns true if allocation was succesful
static Status buffer_line_grow(TextBuffer *buffer, Line *line, u32 minimum_capacity) {
@@ -84,10 +128,9 @@ static Status buffer_line_grow(TextBuffer *buffer, Line *line, u32 minimum_capac
buffer_seterr(buffer, "Line %td is too large.", line - buffer->lines);
return false;
}
- char32_t *new_str = realloc(line->str, new_capacity * sizeof *line->str);
+ char32_t *new_str = buffer_realloc(buffer, line->str, new_capacity * sizeof *line->str);
if (!new_str) {
// allocation failed ):
- buffer_out_of_mem(buffer);
return false;
}
// allocation successful
@@ -103,14 +146,13 @@ static Status buffer_lines_grow(TextBuffer *buffer, u32 minimum_capacity) {
while (minimum_capacity >= buffer->lines_capacity) {
// allocate more lines
u32 new_capacity = buffer->lines_capacity * 2;
- Line *new_lines = realloc(buffer->lines, new_capacity * sizeof *buffer->lines);
+ Line *new_lines = buffer_realloc(buffer, buffer->lines, new_capacity * sizeof *buffer->lines);
if (new_lines) {
buffer->lines = new_lines;
buffer->lines_capacity = new_capacity;
// zero new lines
memset(buffer->lines + buffer->nlines, 0, (new_capacity - buffer->nlines) * sizeof *buffer->lines);
} else {
- buffer_out_of_mem(buffer);
return false;
}
}
@@ -157,46 +199,48 @@ Status buffer_load_file(TextBuffer *buffer, char const *filename) {
return false;
}
- u8 *file_contents = malloc(file_size);
+ u8 *file_contents = buffer_calloc(buffer, 1, file_size);
bool success = true;
if (file_contents) {
buffer->lines_capacity = 4;
- buffer->lines = calloc(buffer->lines_capacity, sizeof *buffer->lines); // initial lines
- buffer->nlines = 1;
- size_t bytes_read = fread(file_contents, 1, file_size, fp);
- if (bytes_read == file_size) {
- char32_t c = 0;
- mbstate_t mbstate = {0};
- for (u8 *p = file_contents, *end = p + file_size; p != end; ) {
- if (*p == '\r' && p != end-1 && p[1] == '\n') {
- // CRLF line endings
- p += 2;
- c = U'\n';
- } else {
- size_t n = mbrtoc32(&c, (char *)p, (size_t)(end - p), &mbstate);
- if (n == 0) {
- // null character
- c = 0;
- ++p;
- } else if (n == (size_t)(-3)) {
- // no bytes consumed, but a character was produced
- } else if (n == (size_t)(-2) || n == (size_t)(-1)) {
- // incomplete character at end of file or invalid UTF-8 respectively; fail
- success = false;
- buffer_seterr(buffer, "Invalid UTF-8 (position: %td).", p - file_contents);
- break;
+ buffer->lines = buffer_calloc(buffer, buffer->lines_capacity, sizeof *buffer->lines); // initial lines
+ if (buffer->lines) {
+ buffer->nlines = 1;
+ size_t bytes_read = fread(file_contents, 1, file_size, fp);
+ if (bytes_read == file_size) {
+ char32_t c = 0;
+ mbstate_t mbstate = {0};
+ for (u8 *p = file_contents, *end = p + file_size; p != end; ) {
+ if (*p == '\r' && p != end-1 && p[1] == '\n') {
+ // CRLF line endings
+ p += 2;
+ c = U'\n';
} else {
- p += n;
+ size_t n = mbrtoc32(&c, (char *)p, (size_t)(end - p), &mbstate);
+ if (n == 0) {
+ // null character
+ c = 0;
+ ++p;
+ } else if (n == (size_t)(-3)) {
+ // no bytes consumed, but a character was produced
+ } else if (n == (size_t)(-2) || n == (size_t)(-1)) {
+ // incomplete character at end of file or invalid UTF-8 respectively; fail
+ success = false;
+ buffer_seterr(buffer, "Invalid UTF-8 (position: %td).", p - file_contents);
+ break;
+ } else {
+ p += n;
+ }
+ }
+ if (c == U'\n') {
+ if (buffer_lines_grow(buffer, buffer->nlines + 1))
+ ++buffer->nlines;
+ } else {
+ u32 line_idx = buffer->nlines - 1;
+ Line *line = &buffer->lines[line_idx];
+
+ buffer_line_append_char(buffer, line, c);
}
- }
- if (c == U'\n') {
- if (buffer_lines_grow(buffer, buffer->nlines + 1))
- ++buffer->nlines;
- } else {
- u32 line_idx = buffer->nlines - 1;
- Line *line = &buffer->lines[line_idx];
-
- buffer_line_append_char(buffer, line, c);
}
}
}
@@ -985,3 +1029,26 @@ void buffer_backspace_words_at_pos(TextBuffer *buffer, BufferPos *pos, i64 nword
void buffer_backspace_words_at_cursor(TextBuffer *buffer, i64 nwords) {
buffer_backspace_words_at_pos(buffer, &buffer->cursor_pos, nwords);
}
+
+static void buffer_undo(TextBuffer *buffer, i64 ntimes) {
+ for (i64 i = 0; i < ntimes; ++i) {
+ BufferEdit *edit = buffer->undo_history;
+ BufferEdit *inverse = NULL;
+ switch (edit->type) {
+ case BUFFER_EDIT_DELETE_LINE: {
+ // let's re-insert that line
+ buffer_insert_lines(buffer, edit->line, 1);
+ BufferPos pos = {.line = edit->line, .index = 0};
+ String32 str = {edit->prev_str_len, edit->prev_str};
+ buffer_insert_text_at_pos(buffer, pos, str);
+ inverse = buffer_calloc(buffer, 1, sizeof *inverse);
+
+ } break;
+ }
+ assert(inverse);
+ buffer->undo_history = edit->next;
+ inverse->next = buffer->redo_history;
+ buffer->redo_history = inverse;
+ }
+}
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-26 05:22:01 +0000