Add support for an immediate "press" event callback

README.md

@@ -150,7 +150,8 @@ Here's a full list of events handled by this library:
 
 | Attach Function         | Description                                                   |
 | ----------------------- | ------------------------------------------------------------- |
-| `attachClick`           | Fires as soon as a single click is detected.                  |
+| `attachPress`           | Fires as soon as a press is detected.                         |
+| `attachClick`           | Fires as soon as a single click press and release is detected.|
 | `attachDoubleClick`     | Fires as soon as a double click is detected.                  |
 | `attachMultiClick`      | Fires as soon as multiple clicks have been detected.          |
 | `attachLongPressStart`  | Fires as soon as the button is held down for 800 milliseconds.|
@@ -175,12 +176,16 @@ This is because a single click callback must not to be triggered in case of a do
 | `setPressMs(int)`       | `800 msec` | Duration to hold a button to trigger a long press.            |
 
 You may change these default values but be aware that when you specify too short times
-it is hard to click twice or you will create a press instead of a click.
+it is hard to click twice or you will create a long press instead of a click.
 
 The former functions `setDebounceTicks`, `setClickTicks` and `setPressTicks` are marked deprecated.
 The term `Ticks` in these functions where confusing. Replace them with the ...Ms function calls.
 There is no functional change on them.
 
+Set debounce ms to a negative value to only debounce on release. `setDebounceMs(-25);` will immediately
+update to a pressed state, and will debounce for 25ms going into the released state. This will expidite
+the `attachPress` callback function to run instantly.
+
 
 ### Additional Functions
 

src/OneButton.cpp

@@ -59,7 +59,7 @@ OneButton::OneButton(const int pin, const bool activeLow, const bool pullupActiv
 
 
 // explicitly set the number of millisec that have to pass by before a click is assumed stable.
-void OneButton::setDebounceMs(const unsigned int ms)
+void OneButton::setDebounceMs(const int ms)
 {
   _debounce_ms = ms;
 } // setDebounceMs
@@ -84,6 +84,20 @@ void OneButton::setIdleMs(const unsigned int ms)
   _idle_ms = ms;
 } // setIdleMs
 
+// save function for click event
+void OneButton::attachPress(callbackFunction newFunction)
+{
+  _pressFunc = newFunction;
+} // attachPress
+
+
+// save function for parameterized click event
+void OneButton::attachPress(parameterizedCallbackFunction newFunction, void *parameter)
+{
+  _paramPressFunc = newFunction;
+  _pressFuncParam = parameter;
+} // attachPress
+
 // save function for click event
 void OneButton::attachClick(callbackFunction newFunction)
 {
@@ -204,28 +218,33 @@ int OneButton::getNumberClicks(void)
 /**
  * @brief Debounce input pin level for use in SpesialInput.
  */
-int OneButton::debounce(const int value) {
+bool OneButton::debounce(const bool value) {
     now = millis(); // current (relative) time in msecs.
-    if (_lastDebouncePinLevel == value) {
-      if (now - _lastDebounceTime >= _debounce_ms)
-        debouncedPinLevel = value;
+
+    // Don't debounce going into active state, if _debounce_ms is negative
+    if(value && _debounce_ms < 0)
+      debouncedLevel = value;
+
+    if (_lastDebounceLevel == value) {
+      if (now - _lastDebounceTime >= abs(_debounce_ms))
+        debouncedLevel = value;
     } else {
       _lastDebounceTime = now;
-      _lastDebouncePinLevel = value;
+      _lastDebounceLevel = value;
     }
-    return debouncedPinLevel;
+    return debouncedLevel;
 };
 
 
 /**
  * @brief Check input of the configured pin,
- * debounce input pin level and then
+ * debounce button state and then
  * advance the finite state machine (FSM).
  */
 void OneButton::tick(void)
 {
   if (_pin >= 0) {
-    _fsm(debounce(digitalRead(_pin)) == _buttonPressed);
+    _fsm(debounce(digitalRead(_pin) == _buttonPressed));
   }
 } // tick()
 
@@ -267,6 +286,9 @@ void OneButton::_fsm(bool activeLevel)
       _newState(OneButton::OCS_DOWN);
       _startTime = now; // remember starting time
       _nClicks = 0;
+
+      if (_pressFunc) _pressFunc();
+      if (_paramPressFunc) _paramPressFunc(_pressFuncParam);
     } // if
     break;
 

src/OneButton.h

@@ -56,7 +56,7 @@ class OneButton
    */
   [[deprecated("Use setDebounceMs() instead.")]]
   void setDebounceTicks(const unsigned int ms) { setDebounceMs(ms); }; // deprecated
-  void setDebounceMs(const unsigned int ms);
+  void setDebounceMs(const int ms);
 
   /**
    * set # millisec after single click is assumed.
@@ -85,6 +85,13 @@ class OneButton
 
   // ----- Attach events functions -----
 
+  /**
+   * Attach an event to be called immediately when a depress is detected.
+   * @param newFunction This function will be called when the event has been detected.
+   */
+  void attachPress(callbackFunction newFunction);
+  void attachPress(parameterizedCallbackFunction newFunction, void *parameter);
+
   /**
    * Attach an event to be called when a single click is detected.
    * @param newFunction This function will be called when the event has been detected.
@@ -177,7 +184,7 @@ class OneButton
 
 private:
   int _pin = -1;                  // hardware pin number.
-  unsigned int _debounce_ms = 50; // number of msecs for debounce times.
+  int _debounce_ms = 50; // number of msecs for debounce times.
   unsigned int _click_ms = 400;   // number of msecs before a click is detected.
   unsigned int _press_ms = 800;   // number of msecs before a long button press is detected
   unsigned int _idle_ms = 1000;   // number of msecs before idle is detected
@@ -187,6 +194,10 @@ class OneButton
                           // HIGH if the button connects the input pin to VCC when pressed.
 
   // These variables will hold functions acting as event source.
+  callbackFunction _pressFunc = NULL;
+  parameterizedCallbackFunction _paramPressFunc = NULL;
+  void *_pressFuncParam = NULL;
+
   callbackFunction _clickFunc = NULL;
   parameterizedCallbackFunction _paramClickFunc = NULL;
   void *_clickFuncParam = NULL;
@@ -241,8 +252,8 @@ class OneButton
 
   bool _idleState = false;
 
-  int debouncedPinLevel = -1;
-  int _lastDebouncePinLevel = -1;      // used for pin debouncing
+  bool debouncedLevel = false;
+  bool _lastDebounceLevel = false;         // used for pin debouncing
   unsigned long _lastDebounceTime = 0; // millis()
   unsigned long now = 0;               // millis()
 
@@ -256,8 +267,8 @@ class OneButton
 public:
   int pin() const { return _pin; };
   stateMachine_t state() const { return _state; };
-  int debounce(const int value);
-  int debouncedValue() const { return debouncedPinLevel; };
+  bool debounce(const bool value);
+  int debouncedValue() const { return debouncedLevel; };
 
   /**
    * @brief Use this function in the DuringLongPress and LongPressStop events to get the time since the button was pressed.