diff options
| -rw-r--r-- | buffer.c | 139 |
1 files changed, 83 insertions, 56 deletions
@@ -145,6 +145,32 @@ static bool buffer_pos_valid(TextBuffer *buffer, BufferPos p) { return p.line < buffer->nlines && p.index <= buffer->lines[p.line].len; } +// code point at position. +// returns 0 if the position is invalid. note that it can also return 0 for a valid position, if there's a null character there +char32_t buffer_char_at_pos(TextBuffer *buffer, BufferPos p) { + if (p.line >= buffer->nlines) + return 0; // invalid (line too large) + + Line *line = &buffer->lines[p.line]; + if (p.index < line->len) { + return line->str[p.index]; + } else if (p.index > line->len) { + // invalid (col too large) + return 0; + } else { + return U'\n'; + } +} + +BufferPos buffer_start_pos(TextBuffer *buffer) { + (void)buffer; + return (BufferPos){.line = 0, .index = 0}; +} + +BufferPos buffer_end_pos(TextBuffer *buffer) { + return (BufferPos){.line = buffer->nlines - 1, .index = buffer->lines[buffer->nlines-1].len}; +} + // get some number of characters of text from the given position in the buffer. static Status buffer_get_text_at_pos(TextBuffer *buffer, BufferPos pos, char32_t *text, size_t nchars) { @@ -178,6 +204,57 @@ static Status buffer_get_text_at_pos(TextBuffer *buffer, BufferPos pos, char32_t return true; } +static BufferPos buffer_pos_advance(TextBuffer *buffer, BufferPos pos, size_t nchars) { + buffer_pos_validate(buffer, &pos); + 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) { + u32 chars_from_this_line = line->len - index; + if (chars_left <= chars_from_this_line) { + index += chars_left; + pos.index = index; + pos.line = (u32)(line - buffer->lines); + return pos; + } + chars_left -= chars_from_this_line+1; // +1 for newline + index = 0; + ++line; + } + return buffer_end_pos(buffer); +} + + +// returns "p2 - p1", that is, the number of characters between p1 and p2. +static i64 buffer_pos_diff(TextBuffer *buffer, BufferPos p1, BufferPos p2) { + assert(buffer_pos_valid(buffer, p1)); + assert(buffer_pos_valid(buffer, p2)); + + if (p1.line == p2.line) { + // p1 and p2 are in the same line + return (i64)p2.index - p1.index; + } + i64 factor = 1; + if (p1.line > p2.line) { + // switch positions so p2 has the later line + BufferPos tmp = p1; + p1 = p2; + p2 = tmp; + factor = -1; + } + + assert(p2.line > p1.line); + i64 chars_at_end_of_p1_line = buffer->lines[p1.line].len - p1.index + 1; // + 1 for newline + i64 chars_at_start_of_p2_line = p2.index; + i64 chars_in_lines_in_between = 0; + // now we need to add up the lengths of the lines between p1 and p2 + for (Line *line = buffer->lines + (p1.line + 1), *end = buffer->lines + p2.line; line != end; ++line) { + chars_in_lines_in_between += line->len; + } + i64 total = chars_at_end_of_p1_line + chars_in_lines_in_between + chars_at_start_of_p2_line; + 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) { @@ -216,6 +293,12 @@ static void buffer_edit_delete_text(TextBuffer *buffer, BufferPos start, size_t 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); @@ -621,32 +704,6 @@ void buffer_render(TextBuffer *buffer, float x1, float y1, float x2, float y2) { } } -// code point at position. -// returns 0 if the position is invalid. note that it can also return 0 for a valid position, if there's a null character there -char32_t buffer_char_at_pos(TextBuffer *buffer, BufferPos p) { - if (p.line >= buffer->nlines) - return 0; // invalid (line too large) - - Line *line = &buffer->lines[p.line]; - if (p.index < line->len) { - return line->str[p.index]; - } else if (p.index > line->len) { - // invalid (col too large) - return 0; - } else { - return U'\n'; - } -} - -BufferPos buffer_start_pos(TextBuffer *buffer) { - (void)buffer; - return (BufferPos){.line = 0, .index = 0}; -} - -BufferPos buffer_end_pos(TextBuffer *buffer) { - return (BufferPos){.line = buffer->nlines - 1, .index = buffer->lines[buffer->nlines-1].len}; -} - // if the cursor is offscreen, this will scroll to make it onscreen. static void buffer_scroll_to_cursor(TextBuffer *buffer) { i64 cursor_line = buffer->cursor_pos.line; @@ -674,36 +731,6 @@ static void buffer_scroll_to_cursor(TextBuffer *buffer) { buffer_correct_scroll(buffer); // it's possible that min/max_scroll_x/y go too far } -// returns "p2 - p1", that is, the number of characters between p1 and p2. -static i64 buffer_pos_diff(TextBuffer *buffer, BufferPos p1, BufferPos p2) { - assert(buffer_pos_valid(buffer, p1)); - assert(buffer_pos_valid(buffer, p2)); - - if (p1.line == p2.line) { - // p1 and p2 are in the same line - return (i64)p2.index - p1.index; - } - i64 factor = 1; - if (p1.line > p2.line) { - // switch positions so p2 has the later line - BufferPos tmp = p1; - p1 = p2; - p2 = tmp; - factor = -1; - } - - assert(p2.line > p1.line); - i64 chars_at_end_of_p1_line = buffer->lines[p1.line].len - p1.index + 1; // + 1 for newline - i64 chars_at_start_of_p2_line = p2.index; - i64 chars_in_lines_in_between = 0; - // now we need to add up the lengths of the lines between p1 and p2 - for (Line *line = buffer->lines + (p1.line + 1), *end = buffer->lines + p2.line; line != end; ++line) { - chars_in_lines_in_between += line->len; - } - i64 total = chars_at_end_of_p1_line + chars_in_lines_in_between + chars_at_start_of_p2_line; - return total * factor; -} - // move left (if `by` is negative) or right (if `by` is positive) by the specified amount. // returns the signed number of characters successfully moved (it could be less in magnitude than `by` if the beginning of the file is reached) i64 buffer_pos_move_horizontally(TextBuffer *buffer, BufferPos *p, i64 by) { |