AceButton.h

/*
MIT License

Copyright (c) 2018 Brian T. Park

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

#ifndef ACE_BUTTON_ACE_BUTTON_H
#define ACE_BUTTON_ACE_BUTTON_H

#include <Arduino.h>
#include "ButtonConfig.h"

namespace ace_button {

class AceButton {
  public:
    // The supported event types.

    static const uint8_t kEventPressed = 0;

    static const uint8_t kEventReleased = 1;

    static const uint8_t kEventClicked = 2;

    static const uint8_t kEventDoubleClicked = 3;

    static const uint8_t kEventLongPressed = 4;

    static const uint8_t kEventRepeatPressed = 5;

    static const uint8_t kButtonStateUnknown = 2;

    explicit AceButton(uint8_t pin = 0, uint8_t defaultReleasedState = HIGH,
        uint8_t id = 0);

    explicit AceButton(ButtonConfig* buttonConfig);

    void init(uint8_t pin = 0, uint8_t defaultReleasedState = HIGH,
        uint8_t id = 0);

    ButtonConfig* getButtonConfig() ACE_BUTTON_INLINE {
      return mButtonConfig;
    }

    void setButtonConfig(ButtonConfig* buttonConfig) ACE_BUTTON_INLINE {
      mButtonConfig = buttonConfig;
    }

    void setEventHandler(ButtonConfig::EventHandler eventHandler)
        ACE_BUTTON_INLINE {
      mButtonConfig->setEventHandler(eventHandler);
    }

    uint8_t getPin() ACE_BUTTON_INLINE { return mPin; }

    uint8_t getId() ACE_BUTTON_INLINE { return mId; }

    uint8_t getDefaultReleasedState();

    uint8_t getLastButtonState() ACE_BUTTON_INLINE {
      return mLastButtonState;
    }

    void check();

    bool isReleased(uint8_t buttonState) ACE_BUTTON_INLINE {
      return buttonState == getDefaultReleasedState();
    }

    bool isPressedRaw() ACE_BUTTON_INLINE {
      return !isReleased(mButtonConfig->readButton(mPin));
    }

  // Some of these private methods may be useful to the calling client but I
  // don't want to release them to the public because I want to keep the API as
  // small as possible for easier long term maintenance. (Once a method is
  // released to the public, it must be supported forever to ensure backwards
  // compatibility with older client code.)

  private:
    // Disable copy-constructor and assignment operator
    AceButton(const AceButton&) = delete;
    AceButton& operator=(const AceButton&) = delete;

    void setPin(uint8_t pin) ACE_BUTTON_INLINE { mPin = pin; }

    void setDefaultReleasedState(uint8_t state);

    void setId(uint8_t id) ACE_BUTTON_INLINE { mId = id; }

    // Various bit masks to store a boolean flag in the 'mFlags' field.
    // We use bit masks to save static RAM. If we had used a 'bool' type, each
    // of these would consume one byte.
    static const uint8_t kFlagDefaultReleasedState = 0x01;
    static const uint8_t kFlagDebouncing = 0x02;
    static const uint8_t kFlagPressed = 0x04;
    static const uint8_t kFlagClicked = 0x08;
    static const uint8_t kFlagDoubleClicked = 0x10;
    static const uint8_t kFlagLongPressed = 0x20;
    static const uint8_t kFlagRepeatPressed = 0x40;
    static const uint8_t kFlagClickPostponed = 0x80;

    // Methods for accessing the button's internal states.
    // I don't expect these to be useful to the outside world.

    // If this is set, then mLastDebounceTime is valid.
    bool isDebouncing() ACE_BUTTON_INLINE {
      return mFlags & kFlagDebouncing;
    }

    void setDebouncing() ACE_BUTTON_INLINE {
      mFlags |= kFlagDebouncing;
    }

    void clearDebouncing() ACE_BUTTON_INLINE {
      mFlags &= ~kFlagDebouncing;
    }

    // If this is set, then mLastPressTime is valid.
    bool isPressed() ACE_BUTTON_INLINE {
      return mFlags & kFlagPressed;
    }

    void setPressed() ACE_BUTTON_INLINE {
      mFlags |= kFlagPressed;
    }

    void clearPressed() ACE_BUTTON_INLINE {
      mFlags &= ~kFlagPressed;
    }

    // If this is set, then mLastClickTime is valid.
    bool isClicked() ACE_BUTTON_INLINE {
      return mFlags & kFlagClicked;
    }

    void setClicked() ACE_BUTTON_INLINE {
      mFlags |= kFlagClicked;
    }

    void clearClicked() ACE_BUTTON_INLINE {
      mFlags &= ~kFlagClicked;
    }

    // A double click was detected. No need to store the last double-clicked
    // time because we don't support a triple-click event (yet).
    bool isDoubleClicked() ACE_BUTTON_INLINE {
      return mFlags & kFlagDoubleClicked;
    }

    void setDoubleClicked() ACE_BUTTON_INLINE {
      mFlags |= kFlagDoubleClicked;
    }

    void clearDoubleClicked() ACE_BUTTON_INLINE {
      mFlags &= ~kFlagDoubleClicked;
    }

    // If this is set, then mLastPressTime can be treated as the start
    // of a long press.
    bool isLongPressed() ACE_BUTTON_INLINE {
      return mFlags & kFlagLongPressed;
    }

    void setLongPressed() ACE_BUTTON_INLINE {
      mFlags |= kFlagLongPressed;
    }

    void clearLongPressed() ACE_BUTTON_INLINE {
      mFlags &= ~kFlagLongPressed;
    }

    // If this is set, then mLastRepeatPressTime is valid.
    bool isRepeatPressed() ACE_BUTTON_INLINE {
      return mFlags & kFlagRepeatPressed;
    }

    void setRepeatPressed() ACE_BUTTON_INLINE {
      mFlags |= kFlagRepeatPressed;
    }

    void clearRepeatPressed() ACE_BUTTON_INLINE {
      mFlags &= ~kFlagRepeatPressed;
    }

    bool isClickPostponed() ACE_BUTTON_INLINE {
      return mFlags & kFlagClickPostponed;
    }

    void setClickPostponed() ACE_BUTTON_INLINE {
      mFlags |= kFlagClickPostponed;
    }

    void clearClickPostponed() ACE_BUTTON_INLINE {
      mFlags &= ~kFlagClickPostponed;
    }

    bool checkDebounced(uint16_t now, uint8_t buttonState);

    bool checkInitialized(uint16_t buttonState);

    void checkEvent(uint16_t now, uint8_t buttonState);

    void checkLongPress(uint16_t now, uint8_t buttonState);

    void checkRepeatPress(uint16_t now, uint8_t buttonState);

    void checkChanged(uint16_t now, uint8_t buttonState);

    void checkReleased(uint16_t now, uint8_t buttonState);

    void checkPressed(uint16_t now, uint8_t buttonState);

    void checkClicked(uint16_t now);

    void checkDoubleClicked(uint16_t now);

    void checkOrphanedClick(uint16_t now);

    void checkPostponedClick(uint16_t now);

    void handleEvent(uint8_t eventType);

    uint8_t mPin; // button pin number
    uint8_t mId; // identifier, e.g. an index into an array

    // Internal states of the button debouncing and event handling.
    // NOTE: We don't keep track of the lastDoubleClickTime, because we
    // don't support a TripleClicked event. That may change in the future.
    uint16_t mLastDebounceTime; // ms
    uint16_t mLastClickTime; // ms
    uint16_t mLastPressTime; // ms
    uint16_t mLastRepeatPressTime; // ms

    uint8_t mFlags;

    uint8_t mLastButtonState;

    ButtonConfig* mButtonConfig;
};

}
#endif