diff options
| -rw-r--r-- | buffer.c | 156 |
1 files changed, 73 insertions, 83 deletions
@@ -18,17 +18,12 @@ typedef struct { char32_t *str; } Line; -typedef enum { - BUFFER_EDIT_DELETE_TEXT, // text = deleted text, text_len = length of text deleted, pos = where text was deleted (first character) - BUFFER_EDIT_INSERT_TEXT // text = NULL, text_len = length of text inserted, pos = where text was inserted (first character) - // (we don't need to know what text was inserted for BUFFER_EDIT_INSERT_TEXT, since it'll be right there) -} BufferEditType; - +// this refers to replacing prev_len characters (found in prev_text) at pos with new_len characters typedef struct BufferEdit { - BufferEditType type; BufferPos pos; - size_t text_len; - char32_t *text; + size_t new_len; + size_t prev_len; + char32_t *prev_text; } BufferEdit; typedef struct { @@ -94,7 +89,7 @@ static void buffer_out_of_mem(TextBuffer *buffer) { static void buffer_edit_free(BufferEdit *edit) { - free(edit->text); + free(edit->prev_text); } static void buffer_clear_redo_history(TextBuffer *buffer) { @@ -184,10 +179,10 @@ static Status buffer_get_text_at_pos(TextBuffer *buffer, BufferPos pos, char32_t while (chars_left) { u32 chars_from_this_line = line->len - index; if (chars_left <= chars_from_this_line) { - memcpy(p, line->str, chars_left); + memcpy(p, line->str, chars_left * sizeof *p); chars_left = 0; } else { - memcpy(p, line->str, chars_from_this_line); + memcpy(p, line->str, chars_from_this_line * sizeof *p); p += chars_from_this_line; *p++ = U'\n'; chars_left -= chars_from_this_line+1; @@ -209,7 +204,7 @@ static BufferPos buffer_pos_advance(TextBuffer *buffer, BufferPos pos, size_t nc size_t chars_left = nchars; Line *line = &buffer->lines[pos.line], *end = buffer->lines + buffer->nlines; u32 index = pos.index; - while (chars_left && line != end) { + while (line != end) { u32 chars_from_this_line = line->len - index; if (chars_left <= chars_from_this_line) { index += chars_left; @@ -255,17 +250,20 @@ static i64 buffer_pos_diff(TextBuffer *buffer, BufferPos p1, BufferPos p2) { return total * factor; } -// functions for creating buffer edits: -// call these before you make an edit to create an undo event -static Status buffer_create_edit_delete_text(TextBuffer *buffer, BufferEdit *edit, BufferPos start, size_t len) { - edit->text = calloc(1, len * sizeof *edit->text); - if (edit->text) { - edit->type = BUFFER_EDIT_DELETE_TEXT; +static Status buffer_create_edit(TextBuffer *buffer, BufferEdit *edit, BufferPos start, size_t prev_len, size_t new_len) { + if (prev_len == 0) + edit->prev_text = NULL; // if there's no previous text, don't allocate anything + else + edit->prev_text = calloc(1, prev_len * sizeof *edit->prev_text); + if (prev_len == 0 || edit->prev_text) { edit->pos = start; - edit->text_len = len; - if (!buffer_get_text_at_pos(buffer, start, edit->text, len)) { - free(edit->text); - return false; + edit->prev_len = prev_len; + edit->new_len = new_len; + if (prev_len) { + if (!buffer_get_text_at_pos(buffer, start, edit->prev_text, prev_len)) { + buffer_edit_free(edit); + return false; + } } return true; } else { @@ -273,36 +271,12 @@ static Status buffer_create_edit_delete_text(TextBuffer *buffer, BufferEdit *edi } } -static Status buffer_create_edit_insert_text(TextBuffer *buffer, BufferEdit *edit, BufferPos start, size_t len) { - if (!buffer_pos_valid(buffer, start)) return false; - edit->type = BUFFER_EDIT_INSERT_TEXT; - edit->pos = start; - edit->text_len = len; - edit->text = NULL; - return true; -} - -static void buffer_edit_delete_text(TextBuffer *buffer, BufferPos start, size_t len) { - if (buffer->store_undo_events) { - BufferEdit edit = {0}; - if (buffer_create_edit_delete_text(buffer, &edit, start, len)) { - buffer_append_edit(buffer, &edit); - } - } -} - -static void buffer_edit_insert_text(TextBuffer *buffer, BufferPos start, size_t len) { - if (buffer->store_undo_events) { - BufferEdit *last_edit = buffer->undo_history; - i64 where_in_last_edit = buffer_pos_diff(buffer, last_edit->pos, start); - if (where_in_last_edit >= 0 && where_in_last_edit < (i64)last_edit->text_len) { - // @TODO - } - - BufferEdit edit = {0}; - if (buffer_create_edit_insert_text(buffer, &edit, start, len)) { - buffer_append_edit(buffer, &edit); - } +// add this edit to the undo history +// call this before actually changing buffer +static void buffer_edit(TextBuffer *buffer, BufferPos start, size_t prev_len, size_t new_len) { + BufferEdit edit = {0}; + if (buffer_create_edit(buffer, &edit, start, prev_len, new_len)) { + buffer_append_edit(buffer, &edit); } } @@ -976,7 +950,18 @@ static void buffer_insert_lines(TextBuffer *buffer, u32 where, u32 number) { // inserts the given text, returning the position of the end of the text BufferPos buffer_insert_text_at_pos(TextBuffer *buffer, BufferPos pos, String32 str) { - buffer_edit_insert_text(buffer, pos, str.len); + if (buffer->store_undo_events) { + BufferEdit *last_edit = buffer->undo_history; + i64 where_in_last_edit = last_edit ? buffer_pos_diff(buffer, last_edit->pos, pos) : -1; + if (where_in_last_edit >= 0 && where_in_last_edit <= (i64)last_edit->new_len) { + // merge this edit into the previous one. + last_edit->new_len += str.len; + } else { + // create a new edit for this insertion + buffer_edit(buffer, pos, 0, str.len); + } + + } u32 line_idx = pos.line; u32 index = pos.index; @@ -987,6 +972,7 @@ BufferPos buffer_insert_text_at_pos(TextBuffer *buffer, BufferPos pos, String32 u32 n_added_lines = (u32)str32_count_char(str, U'\n'); if (n_added_lines) { buffer_insert_lines(buffer, line_idx + 1, n_added_lines); + line = &buffer->lines[line_idx]; // fix pointer // move any text past the cursor on this line to the last added line. Line *last_line = &buffer->lines[line_idx + n_added_lines]; u32 chars_moved = line->len - index; @@ -1064,7 +1050,7 @@ static void buffer_shorten(TextBuffer *buffer, u32 new_nlines) { } // delete `nlines` lines starting from index `first_line_idx` -void buffer_delete_lines(TextBuffer *buffer, u32 first_line_idx, u32 nlines) { +static void buffer_delete_lines(TextBuffer *buffer, u32 first_line_idx, u32 nlines) { assert(first_line_idx < buffer->nlines); assert(first_line_idx+nlines <= buffer->nlines); Line *first_line = &buffer->lines[first_line_idx]; @@ -1080,15 +1066,25 @@ void buffer_delete_chars_at_pos(TextBuffer *buffer, BufferPos pos, i64 nchars) { assert(nchars >= 0); if (nchars <= 0) return; - buffer_edit_delete_text(buffer, pos, (size_t)nchars); + if (buffer->store_undo_events) { + BufferEdit *last_edit = buffer->undo_history; + i64 where_in_last_edit = last_edit ? buffer_pos_diff(buffer, last_edit->pos, pos) : -1; + if (where_in_last_edit >= 0 && where_in_last_edit <= (i64)last_edit->new_len) { + // merge this edit into the last one. + } else { + // create a new edit + buffer_edit(buffer, pos, (size_t)nchars, 0); + } + } u32 line_idx = pos.line; u32 index = pos.index; Line *line = &buffer->lines[line_idx], *lines_end = &buffer->lines[buffer->nlines]; if (nchars + index > line->len) { // delete rest of line - buffer_shorten_line(line, index); nchars -= line->len - index + 1; // +1 for the newline that got deleted + buffer_shorten_line(line, index); + Line *last_line; // last line in lines deleted for (last_line = line + 1; last_line < lines_end && nchars > last_line->len; ++last_line) { nchars -= last_line->len+1; @@ -1103,7 +1099,7 @@ void buffer_delete_chars_at_pos(TextBuffer *buffer, BufferPos pos, i64 nchars) { // join last_line to line. u32 last_line_chars_left = (u32)(last_line->len - nchars); if (buffer_line_set_min_capacity(buffer, line, line->len + last_line_chars_left)) { - memcpy(line->str + line->len, last_line->str, last_line_chars_left * sizeof(char32_t)); + memcpy(line->str + line->len, last_line->str + nchars, last_line_chars_left * sizeof(char32_t)); line->len += last_line_chars_left; } // remove all lines between line + 1 and last_line (inclusive). @@ -1169,7 +1165,7 @@ void buffer_backspace_words_at_cursor(TextBuffer *buffer, i64 nwords) { buffer_backspace_words_at_pos(buffer, &buffer->cursor_pos, nwords); } -// returns the inverse edit +// puts the inverse edit into `inverse` static Status buffer_undo_edit(TextBuffer *buffer, BufferEdit const *edit, BufferEdit *inverse) { bool success = false; bool prev_store_undo_events = buffer->store_undo_events; @@ -1177,39 +1173,33 @@ static Status buffer_undo_edit(TextBuffer *buffer, BufferEdit const *edit, Buffe // to the undo history buffer->store_undo_events = false; - switch (edit->type) { - case BUFFER_EDIT_INSERT_TEXT: - // the inverse edit is the deletion of this text - if (buffer_create_edit_delete_text(buffer, inverse, edit->pos, edit->text_len)) { - // delete the text - buffer_delete_chars_at_pos(buffer, edit->pos, (i64)edit->text_len); - - success = true; - } - break; - case BUFFER_EDIT_DELETE_TEXT: { - // the inverse edit is the insertion of this text - if (buffer_create_edit_insert_text(buffer, inverse, edit->pos, edit->text_len)) { - // insert the text - String32 str = {edit->text_len, edit->text}; - buffer_insert_text_at_pos(buffer, edit->pos, str); - - success = true; - } - } break; + // create inverse edit + if (buffer_create_edit(buffer, inverse, edit->pos, edit->new_len, edit->prev_len)) { + buffer_delete_chars_at_pos(buffer, edit->pos, (i64)edit->new_len); + String32 str = {edit->prev_len, edit->prev_text}; + buffer_insert_text_at_pos(buffer, edit->pos, str); + success = true; } + + buffer->store_undo_events = prev_store_undo_events; return success; } +static void buffer_cursor_to_edit(TextBuffer *buffer, BufferEdit *edit) { + buffer->cursor_pos = buffer_pos_advance(buffer, edit->pos, edit->prev_len); +} + void buffer_undo(TextBuffer *buffer, i64 ntimes) { for (i64 i = 0; i < ntimes; ++i) { BufferEdit *edit = arr_lastp(buffer->undo_history); if (edit) { BufferEdit inverse = {0}; if (buffer_undo_edit(buffer, edit, &inverse)) { - buffer->cursor_pos = edit->pos; // put cursor where edit happened - buffer_scroll_to_cursor(buffer); + if (i == ntimes - 1) { + // if we're on the last undo, put cursor where edit is + buffer_cursor_to_edit(buffer, edit); + } buffer_append_redo(buffer, &inverse); buffer_edit_free(edit); @@ -1225,8 +1215,8 @@ void buffer_redo(TextBuffer *buffer, i64 ntimes) { if (edit) { BufferEdit inverse = {0}; if (buffer_undo_edit(buffer, edit, &inverse)) { - buffer->cursor_pos = edit->pos; // put cursor where edit happened - buffer_scroll_to_cursor(buffer); + if (i == ntimes - 1) + buffer_cursor_to_edit(buffer, edit); // NOTE: we can't just use buffer_append_edit, because that clears the redo history arr_add(buffer->undo_history, inverse); |