mirror of
https://github.com/flutter/flutter.git
synced 2026-02-20 02:29:02 +08:00
63 lines
1.8 KiB
C++
63 lines
1.8 KiB
C++
// Copyright (c) 2013 The Chromium Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style license that can be
|
|
// found in the LICENSE file.
|
|
|
|
#ifndef UI_GFX_SEQUENTIAL_ID_GENERATOR_H_
|
|
#define UI_GFX_SEQUENTIAL_ID_GENERATOR_H_
|
|
|
|
#include <map>
|
|
|
|
#include "base/basictypes.h"
|
|
#include "base/containers/hash_tables.h"
|
|
#include "ui/gfx/gfx_export.h"
|
|
|
|
namespace ui {
|
|
|
|
// This is used to generate a series of sequential ID numbers in a way that a
|
|
// new ID is always the lowest possible ID in the sequence.
|
|
class GFX_EXPORT SequentialIDGenerator {
|
|
public:
|
|
// Creates a new generator with the specified lower bound for the IDs.
|
|
explicit SequentialIDGenerator(uint32 min_id);
|
|
~SequentialIDGenerator();
|
|
|
|
// Generates a unique ID to represent |number|. The generated ID is the
|
|
// smallest available ID greater than or equal to the |min_id| specified
|
|
// during creation of the generator.
|
|
uint32 GetGeneratedID(uint32 number);
|
|
|
|
// Checks to see if the generator currently has a unique ID generated for
|
|
// |number|.
|
|
bool HasGeneratedIDFor(uint32 number) const;
|
|
|
|
// Removes the generated ID |id| from the internal mapping. Since the ID is
|
|
// no longer mapped to any number, subsequent calls to |GetGeneratedID()| can
|
|
// use this ID.
|
|
void ReleaseGeneratedID(uint32 id);
|
|
|
|
// Removes the ID previously generated for |number| by calling
|
|
// |GetGeneratedID()|.
|
|
void ReleaseNumber(uint32 number);
|
|
|
|
void ResetForTest();
|
|
|
|
private:
|
|
typedef base::hash_map<uint32, uint32> IDMap;
|
|
|
|
uint32 GetNextAvailableID();
|
|
|
|
void UpdateNextAvailableIDAfterRelease(uint32 id);
|
|
|
|
IDMap number_to_id_;
|
|
IDMap id_to_number_;
|
|
|
|
const uint32 min_id_;
|
|
uint32 min_available_id_;
|
|
|
|
DISALLOW_COPY_AND_ASSIGN(SequentialIDGenerator);
|
|
};
|
|
|
|
} // namespace ui
|
|
|
|
#endif // UI_GFX_SEQUENTIAL_ID_GENERATOR_H_
|