(#354) Integrate history with console

src/ui/console.c

@@ -165,6 +165,7 @@ int console_handle_event(Console *console,
         case SDLK_RETURN: {
             const char *source_code = edit_field_as_text(console->edit_field);
 
+            /* TODO: console pushes empty strings to the history */
             if (history_push(console->history, source_code) < 0) {
                 return -1;
             }
@@ -209,6 +210,20 @@ int console_handle_event(Console *console,
             gc_collect(console->gc, console->scope.expr);
             edit_field_clean(console->edit_field);
         } return 0;
+
+        case SDLK_UP: {
+            edit_field_replace(
+                console->edit_field,
+                history_current(console->history));
+            history_prev(console->history);
+        } return 0;
+
+        case SDLK_DOWN: {
+            edit_field_replace(
+                console->edit_field,
+                history_current(console->history));
+            history_next(console->history);
+        } return 0;
         }
         break;
     }

src/ui/edit_field.c

@@ -245,7 +245,16 @@ static void edit_field_insert_char(Edit_field *edit_field, char c)
 
 void edit_field_clean(Edit_field *edit_field)
 {
+    assert(edit_field);
+
     edit_field->cursor = 0;
     edit_field->buffer_size = 0;
     edit_field->buffer[0] = 0;
 }
+
+void edit_field_replace(Edit_field *edit_field, const char *text)
+{
+    assert(edit_field);
+    assert(text);
+    /* TODO: edit_field_replace is not implemented */
+}

src/ui/edit_field.h

@@ -25,6 +25,7 @@ int edit_field_handle_event(Edit_field *edit_field,
 
 const char *edit_field_as_text(const Edit_field *edit_field);
 
+void edit_field_replace(Edit_field *edit_field, const char *text);
 void edit_field_clean(Edit_field *edit_field);
 
 #endif  // EDIT_FIELD_H_

src/ui/history.c

@@ -12,8 +12,9 @@ struct History
     Lt *lt;
 
     char **buffer;
-    size_t cursor;
+    size_t begin;
     size_t capacity;
+    size_t cursor;
 };
 
 History *create_history(size_t capacity)
@@ -34,6 +35,7 @@ History *create_history(size_t capacity)
     history->lt = lt;
 
     history->capacity = capacity;
+    history->begin = 0;
     history->cursor = 0;
 
     history->buffer = PUSH_LT(lt, calloc(capacity, sizeof(char*)), free);
@@ -63,25 +65,42 @@ int history_push(History *history, const char *command)
     assert(history);
     assert(command);
 
-    const size_t next_cursor = (history->cursor + 1) % history->capacity;
+    const size_t next_begin = (history->begin + 1) % history->capacity;
 
-    if (history->buffer[history->cursor] != NULL) {
+    if (history->buffer[history->begin] != NULL) {
-        free(history->buffer[history->cursor]);
+        free(history->buffer[history->begin]);
     }
 
-    history->buffer[history->cursor] = string_duplicate(command, NULL);
+    history->buffer[history->begin] = string_duplicate(command, NULL);
 
-    if (history->buffer[history->cursor] == NULL) {
+    if (history->buffer[history->begin] == NULL) {
         return -1;
     }
 
-    history->cursor = next_cursor;
+    history->begin = next_begin;
+    history->cursor = next_begin;
 
     return 0;
 }
 
-const char *history_get(History *history, size_t i)
+const char *history_current(History *history)
 {
     assert(history);
-    return history->buffer[(history->cursor + i) % history->capacity];
+    return history->buffer[history->cursor];
+}
+
+void history_prev(History *history)
+{
+    assert(history);
+    if (history->cursor == 0) {
+        history->cursor = history->capacity - 1;
+    } else {
+        history->cursor--;
+    }
+}
+
+void history_next(History *history)
+{
+    assert(history);
+    history->cursor = (history->cursor + 1) % history->capacity;
 }

src/ui/history.h

@@ -7,6 +7,8 @@ History *create_history(size_t capacity);
 void destroy_history(History *history);
 
 int history_push(History *history, const char *command);
-const char *history_get(History *history, size_t i);
+const char *history_current(History *history);
+void history_prev(History *history);
+void history_next(History *history);
 
 #endif  // HISTORY_H_