Tkinter Long Press Detector (Credit: [laurentalacoque](/laurentalacoque))

LongPress.py

#### USAGE!  Attach to self.image (not self.root) that way button clicks do not count as long presses.
#### otherwise the button call backs hang long enough to trigger the long press

## self.longpress_obj = LongPressDetector(self.image, long_press_cb)

class LongPressDetector:
    """Helper class that calls a callback after a long press/click"""
# call_back will get the long_click duration as parameter
    def __init__(self, root, call_back, long_press_duration = 1000 ):
        """Creates the LongPressDetector

        Arguments:
            root (Tk Widget): parent element for the event binding
            call_back       : a callback function with prototype callback(press_duration_ms)
            long_press_duration : amount of milliseconds after which we consider this press is long
        """
        self.ts=0
        self.root = root
        self.call_back = call_back
        self._suspend = False
        self.long_press_duration = long_press_duration
        root.bind("<Button-1>",self.__click)
        root.bind("<ButtonRelease-1>",self.__release)

    def suspend(self):
        """suspend longpress action"""
        self._suspend = True
        self.root.after_cancel(self.after_press_id)
        
    def activate(self):
        """reactivate longpress action"""
        self._suspend = False

    def __click(self,event):
        self.ts = event.time
        if not self._suspend:
            self.after_press_id = self.root.after(self.long_press_duration,
                                                  self.__trigger)
    def __release(self,event):
        if self.after_press_id is not None:
           self.root.after_cancel(self.after_press_id)
        
    def __trigger(self):
        if self.call_back != None:
            self.call_back(self.long_press_duration)
            
    def __del__(self):
        if self.after_press_id is not None:
            self.root.after_cancel(self.after_press_id)