include/input/KeyLayoutMap.h

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#pragma once

#include <android-base/result.h>
#include <stdint.h>
#include <utils/Errors.h>
#include <utils/Tokenizer.h>
#include <set>

#include <input/InputDevice.h>

namespace android {

struct AxisInfo {
    enum Mode {
        // Axis value is reported directly.
        MODE_NORMAL = 0,
        // Axis value should be inverted before reporting.
        MODE_INVERT = 1,
        // Axis value should be split into two axes
        MODE_SPLIT = 2,
    };

    // Axis mode.
    Mode mode;

    // Axis id.
    // When split, this is the axis used for values smaller than the split position.
    int32_t axis;

    // When split, this is the axis used for values after higher than the split position.
    int32_t highAxis;

    // The split value, or 0 if not split.
    int32_t splitValue;

    // The flat value, or -1 if none.
    int32_t flatOverride;

    AxisInfo() : mode(MODE_NORMAL), axis(-1), highAxis(-1), splitValue(0), flatOverride(-1) {
    }
};

/**
 * Describes a mapping from keyboard scan codes and joystick axes to Android key codes and axes.
 *
 * This object is immutable after it has been loaded.
 */
class KeyLayoutMap {
public:
    static base::Result<std::shared_ptr<KeyLayoutMap>> load(const std::string& filename,
                                                            const char* contents = nullptr);
    static base::Result<std::shared_ptr<KeyLayoutMap>> loadContents(const std::string& filename,
                                                                    const char* contents);

    status_t mapKey(int32_t scanCode, int32_t usageCode,
            int32_t* outKeyCode, uint32_t* outFlags) const;
    std::vector<int32_t> findScanCodesForKey(int32_t keyCode) const;
    std::optional<int32_t> findScanCodeForLed(int32_t ledCode) const;
    std::optional<int32_t> findUsageCodeForLed(int32_t ledCode) const;

    std::optional<AxisInfo> mapAxis(int32_t scanCode) const;
    const std::string getLoadFileName() const;
    // Return pair of sensor type and sensor data index, for the input device abs code
    base::Result<std::pair<InputDeviceSensorType, int32_t>> mapSensor(int32_t absCode) const;

    virtual ~KeyLayoutMap();

private:
    static base::Result<std::shared_ptr<KeyLayoutMap>> load(Tokenizer* tokenizer);

    struct Key {
        int32_t keyCode;
        uint32_t flags;
    };

    struct Led {
        int32_t ledCode;
    };

    struct Sensor {
        InputDeviceSensorType sensorType;
        int32_t sensorDataIndex;
    };

    std::unordered_map<int32_t, Key> mKeysByScanCode;
    std::unordered_map<int32_t, Key> mKeysByUsageCode;
    std::unordered_map<int32_t, AxisInfo> mAxes;
    std::unordered_map<int32_t, Led> mLedsByScanCode;
    std::unordered_map<int32_t, Led> mLedsByUsageCode;
    std::unordered_map<int32_t, Sensor> mSensorsByAbsCode;
    std::set<std::string> mRequiredKernelConfigs;
    std::string mLoadFileName;

    KeyLayoutMap();

    const Key* getKey(int32_t scanCode, int32_t usageCode) const;

    class Parser {
        KeyLayoutMap* mMap;
        Tokenizer* mTokenizer;

    public:
        Parser(KeyLayoutMap* map, Tokenizer* tokenizer);
        ~Parser();
        status_t parse();

    private:
        status_t parseKey();
        status_t parseAxis();
        status_t parseLed();
        status_t parseSensor();
        status_t parseRequiredKernelConfig();
    };
};

} // namespace android