scummvm/backends/keymapper/hardware-input.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */

#ifndef COMMON_HARDWARE_KEY_H
#define COMMON_HARDWARE_KEY_H

#include "common/scummsys.h"

#include "common/array.h"
#include "common/events.h"
#include "common/keyboard.h"
#include "common/str.h"

namespace Common {

typedef uint32 HardwareInputCode;

enum HardwareInputType {
	/** Empty / invalid input type */
	kHardwareInputTypeInvalid,
	/** Input that sends single events */
	kHardwareInputTypeGeneric,
	/** Input that usually send -up and -down events */
	kHardwareInputTypeKeyboard
};

/**
* Describes an available hardware input
*/
struct HardwareInput {
	/** unique id used for saving/loading to config */
	String id;

	/** Human readable description */
	String description;

	/** Type tag */
	HardwareInputType type;

	/**
	 * A platform specific unique identifier for an input event
	 * generated when this input is triggered.
	 * This is only relevant when type == kHardwareInputTypeGeneric
	 */
	HardwareInputCode inputCode;

	/**
	 * The KeyState that is generated by the back-end
	 * when this hardware key is pressed.
	 * This is only relevant when type == kHardwareInputTypeKeyboard
	 */
	KeyState key;

	HardwareInput()
		: inputCode(0), type(kHardwareInputTypeInvalid) { }

	HardwareInput(const String &i, HardwareInputCode ic, const String &desc)
		: id(i), inputCode(ic), description(desc), type(kHardwareInputTypeGeneric) { }

	HardwareInput(const String &i, KeyState ky, const String &desc)
		: id(i), inputCode(0), key(ky), description(desc), type(kHardwareInputTypeKeyboard) { }
};

/**
 * Entry in a static table of custom backend hardware inputs
 */
struct HardwareInputTableEntry {
	const char *hwId;
	HardwareInputCode code;
	const char *desc;
};

/**
 * Entry in a static table of available non-modifier keys
 */
struct KeyTableEntry {
	const char *hwId;
	KeyCode keycode;
	const char *desc;
};

/**
 * Entry in a static table of available key modifiers
 */
struct ModifierTableEntry {
	byte flag;
	const char *id;
	const char *desc;
};

/**
 * Interface for querying information about a hardware input device
 */
class HardwareInputSet {
public:
	virtual ~HardwareInputSet();

	/**
	 * Retrieve a hardware input description from an unique identifier
	 *
	 * In case no input was found with the specified id, an empty
	 * HardwareInput structure is return with the type set to
	 * kHardwareInputTypeInvalid.
	 */
	virtual HardwareInput findHardwareInput(const String &id) const = 0;

	/**
	 * Retrieve a hardware input description from one of the events
	 * produced when the input is triggered.
	 *
	 * In case the specified event is not produced by this device,
	 * an empty HardwareInput structure is return with the type set to
	 * kHardwareInputTypeInvalid.
	 */
	virtual HardwareInput findHardwareInput(const Event &event) const = 0;
};

/**
 * A keyboard input device
 *
 * Describes the keys and key + modifiers combinations as HardwareInputs
 */
class KeyboardHardwareInputSet : public HardwareInputSet {
public:
	KeyboardHardwareInputSet(const KeyTableEntry *keys, const ModifierTableEntry *modifiers);

	// HardwareInputSet API
	HardwareInput findHardwareInput(const String &id) const override;
	HardwareInput findHardwareInput(const Event &event) const override;

private:
	const KeyTableEntry *_keys;
	const ModifierTableEntry *_modifiers;
};

/**
 * A custom backend input device
 *
 * @todo This is currently unused. Perhaps it should be removed.
 */
class CustomHardwareInputSet : public HardwareInputSet {
public:
	CustomHardwareInputSet(const HardwareInputTableEntry *hardwareEntries);

	// HardwareInputSet API
	HardwareInput findHardwareInput(const String &id) const override;
	HardwareInput findHardwareInput(const Event &event) const override;

private:
	const HardwareInputTableEntry *_hardwareEntries;
};

/**
 * A composite input device that delegates to a set of actual input devices.
 */
class CompositeHardwareInputSet : public HardwareInputSet {
public:
	~CompositeHardwareInputSet() override;

	// HardwareInputSet API
	HardwareInput findHardwareInput(const String &id) const override;
	HardwareInput findHardwareInput(const Event &event) const override;

	/**
	 * Add an input device to this composite device
	 *
	 * Takes ownership of the hardware input set
	 */
	void addHardwareInputSet(HardwareInputSet *hardwareInputSet);

private:
	Array<HardwareInputSet *> _inputSets;
};

/** A standard set of keyboard keys */
extern const KeyTableEntry defaultKeys[];

/** A standard set of keyboard modifiers */
extern const ModifierTableEntry defaultModifiers[];

} // End of namespace Common

#endif // #ifndef COMMON_HARDWARE_KEY_H