src/game/level/level_editor/undo_history.c

   1 #include <stdlib.h>
   2 #include <stdio.h>
   3
   4 #include <SDL.h>
   5
   6 #include "system/nth_alloc.h"
   7 #include "system/stacktrace.h"
   8 #include "undo_history.h"
   9 #include "config.h"
  10
  11 typedef struct {
  12     RevertAction revert;
  13     void *context_data;
  14     size_t context_data_size;
  15 } HistoryItem;
  16
  17 static
  18 void undo_history_destroy_item(void *item)
  19 {
  20     free(((HistoryItem*)item)->context_data);
  21 }
  22
  23 UndoHistory create_undo_history(void)
  24 {
  25     UndoHistory result;
  26     result.actions = create_ring_buffer(
  27         sizeof(HistoryItem),
  28         UNDO_HISTORY_CAPACITY,
  29         undo_history_destroy_item);
  30     return result;
  31 }
  32
  33 void undo_history_push(UndoHistory *undo_history,
  34                        RevertAction revert,
  35                        void *context_data,
  36                        size_t context_data_size)
  37 {
  38     trace_assert(undo_history);
  39
  40     HistoryItem item = {
  41         .revert = revert,
  42         .context_data = malloc(context_data_size),
  43         .context_data_size = context_data_size
  44     };
  45     trace_assert(item.context_data);
  46     memcpy(item.context_data, context_data, context_data_size);
  47
  48     ring_buffer_push(&undo_history->actions, &item);
  49 }
  50
  51 void undo_history_pop(UndoHistory *undo_history)
  52 {
  53     trace_assert(undo_history);
  54
  55     if (undo_history->actions.count > 0) {
  56         HistoryItem *item = ring_buffer_top(&undo_history->actions);
  57         item->revert(item->context_data, item->context_data_size);
  58         ring_buffer_pop(&undo_history->actions);
  59     }
  60 }
  61
  62 void undo_history_clean(UndoHistory *undo_history)
  63 {
  64     trace_assert(undo_history);
  65
  66     while (undo_history->actions.count) {
  67         ring_buffer_pop(&undo_history->actions);
  68     }
  69 }