include/ui/Input.h

/*
 * Copyright (C) 2010 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.
 */

#ifndef _UI_INPUT_H
#define _UI_INPUT_H

/**
 * Native input event structures.
 */

#include <android/input.h>
#include <utils/Vector.h>
#include <utils/Timers.h>

/*
 * Additional private constants not defined in ndk/ui/input.h.
 */
enum {
    /*
     * Private control to determine when an app is tracking a key sequence.
     */
    KEY_EVENT_FLAG_START_TRACKING = 0x40000000
};

/*
 * Maximum number of pointers supported per motion event.
 */
#define MAX_POINTERS 10

namespace android {

/*
 * A raw event as retrieved from the EventHub.
 */
struct RawEvent {
    nsecs_t when;
    int32_t deviceId;
    int32_t type;
    int32_t scanCode;
    int32_t keyCode;
    int32_t value;
    uint32_t flags;
};

/*
 * Flags that flow alongside events in the input dispatch system to help with certain
 * policy decisions such as waking from device sleep.
 *
 * TODO This enumeration should probably be split up or relabeled for clarity.
 */
enum {
    /* These flags originate in RawEvents and are generally set in the key map. */

    POLICY_FLAG_WAKE = 0x00000001,
    POLICY_FLAG_WAKE_DROPPED = 0x00000002,
    POLICY_FLAG_SHIFT = 0x00000004,
    POLICY_FLAG_CAPS_LOCK = 0x00000008,
    POLICY_FLAG_ALT = 0x00000010,
    POLICY_FLAG_ALT_GR = 0x00000020,
    POLICY_FLAG_MENU = 0x00000040,
    POLICY_FLAG_LAUNCHER = 0x00000080,

    /* These flags are set by the input dispatch policy as it intercepts each event. */

    // Indicates that the screen was off when the event was received and the event
    // should wake the device.
    POLICY_FLAG_WOKE_HERE = 0x10000000,

    // Indicates that the screen was dim when the event was received and the event
    // should brighten the device.
    POLICY_FLAG_BRIGHT_HERE = 0x20000000,
};

/*
 * Pointer coordinate data.
 */
struct PointerCoords {
    float x;
    float y;
    float pressure;
    float size;
};

/*
 * Input events.
 */
struct input_event_t { };

class InputEvent : public input_event_t {
public:
    virtual ~InputEvent() { }

    virtual int32_t getType() const = 0;

    inline int32_t getDeviceId() const { return mDeviceId; }

    inline int32_t getNature() const { return mNature; }

protected:
    void initialize(int32_t deviceId, int32_t nature);

private:
    int32_t mDeviceId;
    int32_t mNature;
};

class KeyEvent : public InputEvent {
public:
    virtual ~KeyEvent() { }

    virtual int32_t getType() const { return INPUT_EVENT_TYPE_KEY; }

    inline int32_t getAction() const { return mAction; }

    inline int32_t getFlags() const { return mFlags; }

    inline int32_t getKeyCode() const { return mKeyCode; }

    inline int32_t getScanCode() const { return mScanCode; }

    inline int32_t getMetaState() const { return mMetaState; }

    inline int32_t getRepeatCount() const { return mRepeatCount; }

    inline nsecs_t getDownTime() const { return mDownTime; }

    inline nsecs_t getEventTime() const { return mEventTime; }

    void initialize(
            int32_t deviceId,
            int32_t nature,
            int32_t action,
            int32_t flags,
            int32_t keyCode,
            int32_t scanCode,
            int32_t metaState,
            int32_t repeatCount,
            nsecs_t downTime,
            nsecs_t eventTime);

private:
    int32_t mAction;
    int32_t mFlags;
    int32_t mKeyCode;
    int32_t mScanCode;
    int32_t mMetaState;
    int32_t mRepeatCount;
    nsecs_t mDownTime;
    nsecs_t mEventTime;
};

class MotionEvent : public InputEvent {
public:
    virtual ~MotionEvent() { }

    virtual int32_t getType() const { return INPUT_EVENT_TYPE_MOTION; }

    inline int32_t getAction() const { return mAction; }

    inline int32_t getEdgeFlags() const { return mEdgeFlags; }

    inline int32_t getMetaState() const { return mMetaState; }

    inline float getXPrecision() const { return mXPrecision; }

    inline float getYPrecision() const { return mYPrecision; }

    inline nsecs_t getDownTime() const { return mDownTime; }

    inline size_t getPointerCount() const { return mPointerIds.size(); }

    inline int32_t getPointerId(size_t pointerIndex) const { return mPointerIds[pointerIndex]; }

    inline nsecs_t getEventTime() const { return mSampleEventTimes[getHistorySize()]; }

    inline float getRawX() const { return mRawX; }

    inline float getRawY() const { return mRawY; }

    inline float getX(size_t pointerIndex) const {
        return getCurrentPointerCoords(pointerIndex).x;
    }

    inline float getY(size_t pointerIndex) const {
        return getCurrentPointerCoords(pointerIndex).y;
    }

    inline float getPressure(size_t pointerIndex) const {
        return getCurrentPointerCoords(pointerIndex).pressure;
    }

    inline float getSize(size_t pointerIndex) const {
        return getCurrentPointerCoords(pointerIndex).size;
    }

    inline size_t getHistorySize() const { return mSampleEventTimes.size() - 1; }

    inline nsecs_t getHistoricalEventTime(size_t historicalIndex) const {
        return mSampleEventTimes[historicalIndex];
    }

    inline float getHistoricalX(size_t pointerIndex, size_t historicalIndex) const {
        return getHistoricalPointerCoords(pointerIndex, historicalIndex).x;
    }

    inline float getHistoricalY(size_t pointerIndex, size_t historicalIndex) const {
        return getHistoricalPointerCoords(pointerIndex, historicalIndex).y;
    }

    inline float getHistoricalPressure(size_t pointerIndex, size_t historicalIndex) const {
        return getHistoricalPointerCoords(pointerIndex, historicalIndex).pressure;
    }

    inline float getHistoricalSize(size_t pointerIndex, size_t historicalIndex) const {
        return getHistoricalPointerCoords(pointerIndex, historicalIndex).size;
    }

    void initialize(
            int32_t deviceId,
            int32_t nature,
            int32_t action,
            int32_t edgeFlags,
            int32_t metaState,
            float rawX,
            float rawY,
            float xPrecision,
            float yPrecision,
            nsecs_t downTime,
            nsecs_t eventTime,
            size_t pointerCount,
            const int32_t* pointerIds,
            const PointerCoords* pointerCoords);

    void addSample(
            nsecs_t eventTime,
            const PointerCoords* pointerCoords);

    void offsetLocation(float xOffset, float yOffset);

private:
    int32_t mAction;
    int32_t mEdgeFlags;
    int32_t mMetaState;
    float mRawX;
    float mRawY;
    float mXPrecision;
    float mYPrecision;
    nsecs_t mDownTime;
    Vector<int32_t> mPointerIds;
    Vector<nsecs_t> mSampleEventTimes;
    Vector<PointerCoords> mSamplePointerCoords;

    inline const PointerCoords& getCurrentPointerCoords(size_t pointerIndex) const {
        return mSamplePointerCoords[getHistorySize() * getPointerCount() + pointerIndex];
    }

    inline const PointerCoords& getHistoricalPointerCoords(
            size_t pointerIndex, size_t historicalIndex) const {
        return mSamplePointerCoords[historicalIndex * getPointerCount() + pointerIndex];
    }
};

/*
 * Input event factory.
 */
class InputEventFactoryInterface {
protected:
    virtual ~InputEventFactoryInterface() { }

public:
    InputEventFactoryInterface() { }

    virtual KeyEvent* createKeyEvent() = 0;
    virtual MotionEvent* createMotionEvent() = 0;
};

/*
 * A simple input event factory implementation that uses a single preallocated instance
 * of each type of input event that are reused for each request.
 */
class PreallocatedInputEventFactory : public InputEventFactoryInterface {
public:
    PreallocatedInputEventFactory() { }
    virtual ~PreallocatedInputEventFactory() { }

    virtual KeyEvent* createKeyEvent() { return & mKeyEvent; }
    virtual MotionEvent* createMotionEvent() { return & mMotionEvent; }

private:
    KeyEvent mKeyEvent;
    MotionEvent mMotionEvent;
};


} // namespace android

#endif // _UI_INPUT_H