diff options
Diffstat (limited to 'examples/dte/change.c')
| -rw-r--r-- | examples/dte/change.c | 417 |
1 files changed, 0 insertions, 417 deletions
diff --git a/examples/dte/change.c b/examples/dte/change.c deleted file mode 100644 index 529036d..0000000 --- a/examples/dte/change.c +++ /dev/null @@ -1,417 +0,0 @@ -#include <stdlib.h> -#include <string.h> -#include "change.h" -#include "buffer.h" -#include "edit.h" -#include "error.h" -#include "util/debug.h" -#include "util/xmalloc.h" - -static ChangeMergeEnum change_merge; -static ChangeMergeEnum prev_change_merge; - -static Change *alloc_change(void) -{ - return xcalloc(sizeof(Change)); -} - -static void add_change(Buffer *buffer, Change *change) -{ - Change *head = buffer->cur_change; - change->next = head; - xrenew(head->prev, head->nr_prev + 1); - head->prev[head->nr_prev++] = change; - buffer->cur_change = change; -} - -// This doesn't need to be local to buffer because commands are atomic -static Change *change_barrier; - -static bool is_change_chain_barrier(const Change *change) -{ - return !change->ins_count && !change->del_count; -} - -static Change *new_change(Buffer *buffer) -{ - if (change_barrier) { - /* - * We are recording series of changes (:replace for example) - * and now we have just made the first change so we have to - * mark beginning of the chain. - * - * We could have done this before when starting the change - * chain but then we may have ended up with an empty chain. - * We don't want to record empty changes ever. - */ - add_change(buffer, change_barrier); - change_barrier = NULL; - } - - Change *change = alloc_change(); - add_change(buffer, change); - return change; -} - -static size_t buffer_offset(const View *view) -{ - return block_iter_get_offset(&view->cursor); -} - -static void record_insert(View *view, size_t len) -{ - Change *change = view->buffer->cur_change; - BUG_ON(!len); - if ( - change_merge == prev_change_merge - && change_merge == CHANGE_MERGE_INSERT - ) { - BUG_ON(change->del_count); - change->ins_count += len; - return; - } - - change = new_change(view->buffer); - change->offset = buffer_offset(view); - change->ins_count = len; -} - -static void record_delete(View *view, char *buf, size_t len, bool move_after) -{ - BUG_ON(!len); - BUG_ON(!buf); - - Change *change = view->buffer->cur_change; - if (change_merge == prev_change_merge) { - if (change_merge == CHANGE_MERGE_DELETE) { - xrenew(change->buf, change->del_count + len); - memcpy(change->buf + change->del_count, buf, len); - change->del_count += len; - free(buf); - return; - } - if (change_merge == CHANGE_MERGE_ERASE) { - xrenew(buf, len + change->del_count); - memcpy(buf + len, change->buf, change->del_count); - change->del_count += len; - free(change->buf); - change->buf = buf; - change->offset -= len; - return; - } - } - - change = new_change(view->buffer); - change->offset = buffer_offset(view); - change->del_count = len; - change->move_after = move_after; - change->buf = buf; -} - -static void record_replace(View *view, char *deleted, size_t del_count, size_t ins_count) -{ - BUG_ON(del_count && !deleted); - BUG_ON(!del_count && deleted); - BUG_ON(!del_count && !ins_count); - - Change *change = new_change(view->buffer); - change->offset = buffer_offset(view); - change->ins_count = ins_count; - change->del_count = del_count; - change->buf = deleted; -} - -void begin_change(ChangeMergeEnum m) -{ - change_merge = m; -} - -void end_change(void) -{ - prev_change_merge = change_merge; -} - -void begin_change_chain(void) -{ - BUG_ON(change_barrier); - - // Allocate change chain barrier but add it to the change tree only if - // there will be any real changes - change_barrier = alloc_change(); - change_merge = CHANGE_MERGE_NONE; -} - -void end_change_chain(View *view) -{ - if (change_barrier) { - // There were no changes in this change chain - free(change_barrier); - change_barrier = NULL; - } else { - // There were some changes; add end of chain marker - add_change(view->buffer, alloc_change()); - } -} - -static void fix_cursors(const View *view, size_t offset, size_t del, size_t ins) -{ - const Buffer *buffer = view->buffer; - for (size_t i = 0, n = buffer->views.count; i < n; i++) { - View *v = buffer->views.ptrs[i]; - if (v != view && offset < v->saved_cursor_offset) { - if (offset + del <= v->saved_cursor_offset) { - v->saved_cursor_offset -= del; - v->saved_cursor_offset += ins; - } else { - v->saved_cursor_offset = offset; - } - } - } -} - -static void reverse_change(View *view, Change *change) -{ - if (view->buffer->views.count > 1) { - fix_cursors(view, change->offset, change->ins_count, change->del_count); - } - - block_iter_goto_offset(&view->cursor, change->offset); - if (!change->ins_count) { - // Convert delete to insert - do_insert(view, change->buf, change->del_count); - if (change->move_after) { - block_iter_skip_bytes(&view->cursor, change->del_count); - } - change->ins_count = change->del_count; - change->del_count = 0; - free(change->buf); - change->buf = NULL; - } else if (change->del_count) { - // Reverse replace - size_t del_count = change->ins_count; - size_t ins_count = change->del_count; - char *buf = do_replace(view, del_count, change->buf, ins_count); - free(change->buf); - change->buf = buf; - change->ins_count = ins_count; - change->del_count = del_count; - } else { - // Convert insert to delete - change->buf = do_delete(view, change->ins_count, true); - change->del_count = change->ins_count; - change->ins_count = 0; - } -} - -bool undo(View *view) -{ - Change *change = view->buffer->cur_change; - view_reset_preferred_x(view); - if (!change->next) { - return false; - } - - if (is_change_chain_barrier(change)) { - unsigned long count = 0; - while (1) { - change = change->next; - if (is_change_chain_barrier(change)) { - break; - } - reverse_change(view, change); - count++; - } - if (count > 1) { - info_msg("Undid %lu changes", count); - } - } else { - reverse_change(view, change); - } - - view->buffer->cur_change = change->next; - return true; -} - -bool redo(View *view, unsigned long change_id) -{ - Change *change = view->buffer->cur_change; - view_reset_preferred_x(view); - if (!change->prev) { - // Don't complain if change_id is 0 - if (change_id) { - error_msg("Nothing to redo"); - } - return false; - } - - const unsigned long nr_prev = change->nr_prev; - BUG_ON(nr_prev == 0); - if (change_id == 0) { - // Default to newest change - change_id = nr_prev - 1; - if (nr_prev > 1) { - unsigned long i = change_id + 1; - info_msg("Redoing newest (%lu) of %lu possible changes", i, nr_prev); - } - } else { - if (--change_id >= nr_prev) { - if (nr_prev == 1) { - return error_msg("There is only 1 possible change to redo"); - } - return error_msg("There are only %lu possible changes to redo", nr_prev); - } - } - - change = change->prev[change_id]; - if (is_change_chain_barrier(change)) { - unsigned long count = 0; - while (1) { - change = change->prev[change->nr_prev - 1]; - if (is_change_chain_barrier(change)) { - break; - } - reverse_change(view, change); - count++; - } - if (count > 1) { - info_msg("Redid %lu changes", count); - } - } else { - reverse_change(view, change); - } - - view->buffer->cur_change = change; - return true; -} - -void free_changes(Change *c) -{ -top: - while (c->nr_prev) { - c = c->prev[c->nr_prev - 1]; - } - - // c is leaf now - while (c->next) { - Change *next = c->next; - free(c->buf); - free(c); - - c = next; - if (--c->nr_prev) { - goto top; - } - - // We have become leaf - free(c->prev); - } -} - -void buffer_insert_bytes(View *view, const char *buf, const size_t len) -{ - view_reset_preferred_x(view); - if (len == 0) { - return; - } - - size_t rec_len = len; - if (buf[len - 1] != '\n' && block_iter_is_eof(&view->cursor)) { - // Force newline at EOF - do_insert(view, "\n", 1); - rec_len++; - } - - do_insert(view, buf, len); - record_insert(view, rec_len); - - if (view->buffer->views.count > 1) { - fix_cursors(view, block_iter_get_offset(&view->cursor), len, 0); - } -} - -static bool would_delete_last_bytes(const View *view, size_t count) -{ - const Block *blk = view->cursor.blk; - size_t offset = view->cursor.offset; - while (1) { - size_t avail = blk->size - offset; - if (avail > count) { - return false; - } - - if (blk->node.next == view->cursor.head) { - return true; - } - - count -= avail; - blk = BLOCK(blk->node.next); - offset = 0; - } -} - -static void buffer_delete_bytes_internal(View *view, size_t len, bool move_after) -{ - view_reset_preferred_x(view); - if (len == 0) { - return; - } - - // Check if all newlines from EOF would be deleted - if (would_delete_last_bytes(view, len)) { - BlockIter bi = view->cursor; - CodePoint u; - if (block_iter_prev_char(&bi, &u) && u != '\n') { - // No newline before cursor - if (--len == 0) { - begin_change(CHANGE_MERGE_NONE); - return; - } - } - } - record_delete(view, do_delete(view, len, true), len, move_after); - - if (view->buffer->views.count > 1) { - fix_cursors(view, block_iter_get_offset(&view->cursor), len, 0); - } -} - -void buffer_delete_bytes(View *view, size_t len) -{ - buffer_delete_bytes_internal(view, len, false); -} - -void buffer_erase_bytes(View *view, size_t len) -{ - buffer_delete_bytes_internal(view, len, true); -} - -void buffer_replace_bytes(View *view, size_t del_count, const char *ins, size_t ins_count) -{ - view_reset_preferred_x(view); - if (del_count == 0) { - buffer_insert_bytes(view, ins, ins_count); - return; - } - if (ins_count == 0) { - buffer_delete_bytes(view, del_count); - return; - } - - // Check if all newlines from EOF would be deleted - if (would_delete_last_bytes(view, del_count)) { - if (ins[ins_count - 1] != '\n') { - // Don't replace last newline - if (--del_count == 0) { - buffer_insert_bytes(view, ins, ins_count); - return; - } - } - } - - char *deleted = do_replace(view, del_count, ins, ins_count); - record_replace(view, deleted, del_count, ins_count); - - if (view->buffer->views.count > 1) { - fix_cursors(view, block_iter_get_offset(&view->cursor), del_count, ins_count); - } -} |