debounce.h

Go to the documentation of this file.

#ifndef SENSESP_TRANSFORMS_DEBOUNCE_H_
#define SENSESP_TRANSFORMS_DEBOUNCE_H_
 
#include "sensesp/ui/config_item.h"
#include "transform.h"
 
namespace sensesp {
 
template <class T>
class Debounce : public SymmetricTransform<T> {
 public:
  Debounce(int ms_min_delay = 15, String config_path = "")
      : SymmetricTransform<T>(config_path), ms_min_delay_{ms_min_delay} {
    this->load();
  }
 
  virtual void set(const T& input) override {
    // Input has changed since the last emit, or this is the first
    // input since the program started to run.
 
    if (input != debounced_value_ || !value_received_) {
      debounced_value_ = input;
 
      if (event_) {
        event_->remove(event_loop());
        event_ = nullptr;
      }
      event_ = event_loop()->onDelay(ms_min_delay_, [this, input]() {
        this->event_ = nullptr;
        this->debounced_value_ = input;
        this->emit(input);
      });
      value_received_ = true;
    }
  }
 
 private:
  int ms_min_delay_;
  bool value_received_ = false;
  T debounced_value_;
  reactesp::DelayEvent* event_ = nullptr;
  virtual bool to_json(JsonObject& doc) override {
    doc["min_delay"] = ms_min_delay_;
    return true;
  }
 
  virtual bool from_json(const JsonObject& config) override {
    const String expected[] = {"min_delay"};
    for (auto str : expected) {
      if (!config[str].is<JsonVariant>()) {
        return false;
      }
    }
    ms_min_delay_ = config["min_delay"];
    return true;
  }
};
 
const String ConfigSchema(const Debounce<bool>& obj);
 
typedef Debounce<bool> DebounceBool;
typedef Debounce<int> DebounceInt;
typedef Debounce<float> DebounceFloat;
 
}  // namespace sensesp
 
#endif