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// Copyright (c) 2012 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_BASE_ACCELERATORS_ACCELERATOR_MANAGER_H_
#define UI_BASE_ACCELERATORS_ACCELERATOR_MANAGER_H_
#include <list>
#include <map>
#include <utility>
#include "base/macros.h"
#include "ui/base/accelerators/accelerator.h"
#include "ui/base/ui_base_export.h"
#include "ui/events/event_constants.h"
namespace ui {
class AcceleratorManagerDelegate;
// AcceleratorManger handles processing of accelerators. A delegate may be
// supplied which is notified as unique accelerators are added and removed.
class UI_BASE_EXPORT AcceleratorManager {
public:
enum HandlerPriority {
kNormalPriority,
kHighPriority,
};
explicit AcceleratorManager(AcceleratorManagerDelegate* = nullptr);
~AcceleratorManager();
// Register a keyboard accelerator for the specified target. If multiple
// targets are registered for an accelerator, a target registered later has
// higher priority.
// |accelerator| is the accelerator to register.
// |priority| denotes the priority of the handler.
// NOTE: In almost all cases, you should specify kNormalPriority for this
// parameter. Setting it to kHighPriority prevents Chrome from sending the
// shortcut to the webpage if the renderer has focus, which is not desirable
// except for very isolated cases.
// |target| is the AcceleratorTarget that handles the event once the
// accelerator is pressed.
// Note that we are currently limited to accelerators that are either:
// - a key combination including Ctrl or Alt
// - the escape key
// - the enter key
// - any F key (F1, F2, F3 ...)
// - any browser specific keys (as available on special keyboards)
void Register(const Accelerator& accelerator,
HandlerPriority priority,
AcceleratorTarget* target);
// Unregister the specified keyboard accelerator for the specified target.
void Unregister(const Accelerator& accelerator, AcceleratorTarget* target);
// Unregister all keyboard accelerator for the specified target.
void UnregisterAll(AcceleratorTarget* target);
// Returns whether |accelerator| is already registered.
bool IsRegistered(const Accelerator& accelerator) const;
// Activate the target associated with the specified accelerator.
// First, AcceleratorPressed handler of the most recently registered target
// is called, and if that handler processes the event (i.e. returns true),
// this method immediately returns. If not, we do the same thing on the next
// target, and so on.
// Returns true if an accelerator was activated.
bool Process(const Accelerator& accelerator);
// Whether the given |accelerator| has a priority handler associated with it.
bool HasPriorityHandler(const Accelerator& accelerator) const;
private:
// The accelerators and associated targets.
using AcceleratorTargetList = std::list<AcceleratorTarget*>;
// This construct pairs together a |bool| (denoting whether the list contains
// a priority_handler at the front) with the list of AcceleratorTargets.
using AcceleratorTargets = std::pair<bool, AcceleratorTargetList>;
using AcceleratorMap = std::map<Accelerator, AcceleratorTargets>;
// Implementation of Unregister(). |map_iter| points to the accelerator to
// remove, and |target| the AcceleratorTarget to remove.
void UnregisterImpl(AcceleratorMap::iterator map_iter,
AcceleratorTarget* target);
AcceleratorManagerDelegate* delegate_;
AcceleratorMap accelerators_;
DISALLOW_COPY_AND_ASSIGN(AcceleratorManager);
};
} // namespace ui
#endif // UI_BASE_ACCELERATORS_ACCELERATOR_MANAGER_H_