gecko-dev/layout/base/nsDisplayItemTypes.h

72 строки
2.0 KiB
C

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=2 sw=2 et tw=78:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
/**
* It's useful to be able to dynamically check the type of certain items.
* Every subclass of nsDisplayItem must have a new type added here for the purposes
* of easy comparison and matching of items in different display lists.
*
* This is #included inside nsDisplayItem.
*/
enum Type {
TYPE_ZERO = 0, /** Spacer so that the first item starts at 1 */
#define DECLARE_DISPLAY_ITEM_TYPE(name) TYPE_##name,
#define DECLARE_DISPLAY_ITEM_TYPE_FLAGS(name,flags) TYPE_##name,
#include "nsDisplayItemTypesList.h"
#undef DECLARE_DISPLAY_ITEM_TYPE
#undef DECLARE_DISPLAY_ITEM_TYPE_FLAGS
TYPE_MAX
};
enum {
// Number of bits needed to represent all types
TYPE_BITS = 8
};
enum DisplayItemFlags {
TYPE_RENDERS_NO_IMAGES = 1 << 0
};
static const char* DisplayItemTypeName(Type aType)
{
switch (aType) {
#define DECLARE_DISPLAY_ITEM_TYPE(name) case TYPE_##name: return #name;
#define DECLARE_DISPLAY_ITEM_TYPE_FLAGS(name,flags) case TYPE_##name: return #name;
#include "nsDisplayItemTypesList.h"
#undef DECLARE_DISPLAY_ITEM_TYPE
#undef DECLARE_DISPLAY_ITEM_TYPE_FLAGS
default: return "TYPE_UNKNOWN";
}
}
static uint8_t GetDisplayItemFlagsForType(Type aType)
{
static const uint8_t flags[TYPE_MAX] = {
0
#define DECLARE_DISPLAY_ITEM_TYPE(name) ,0
#define DECLARE_DISPLAY_ITEM_TYPE_FLAGS(name,flags) ,flags
#include "nsDisplayItemTypesList.h"
#undef DECLARE_DISPLAY_ITEM_TYPE
#undef DECLARE_DISPLAY_ITEM_TYPE_FLAGS
};
return flags[aType];
}
static Type GetDisplayItemTypeFromKey(uint32_t aDisplayItemKey)
{
static const uint32_t typeMask = (1 << TYPE_BITS) - 1;
Type type = static_cast<Type>(aDisplayItemKey & typeMask);
NS_ASSERTION(type > TYPE_ZERO && type < TYPE_MAX, "Invalid display item type!");
return type;
}