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-rw-r--r--buffer.c139
1 files changed, 83 insertions, 56 deletions
diff --git a/buffer.c b/buffer.c
index 5acc536..d337db3 100644
--- a/buffer.c
+++ b/buffer.c
@@ -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) {