Quick search

Table Of Contents

Source code for kivy.input.postproc.doubletap

'''
Double Tap
==========

Search touch for a double tap
'''

__all__ = ('InputPostprocDoubleTap', )

from time import time
from kivy.config import Config
from kivy.vector import Vector


[docs]class InputPostprocDoubleTap(object): ''' InputPostProcDoubleTap is a post-processor to check if a touch is a double tap or not. Double tap can be configured in the Kivy config file:: [postproc] double_tap_time = 250 double_tap_distance = 20 Distance parameter is in the range 0-1000 and time is in milliseconds. ''' def __init__(self): dist = Config.getint('postproc', 'double_tap_distance') self.double_tap_distance = dist / 1000.0 tap_time = Config.getint('postproc', 'double_tap_time') self.double_tap_time = tap_time / 1000.0 self.touches = {}
[docs] def find_double_tap(self, ref): '''Find a double tap touch within self.touches. The touch must be not a previous double tap and the distance must be within the specified threshold. Additionally, the touch profiles must be the same kind of touch. ''' ref_button = None if 'button' in ref.profile: ref_button = ref.button for touchid in self.touches: if ref.uid == touchid: continue etype, touch = self.touches[touchid] if etype != 'end': continue if touch.is_double_tap: continue distance = Vector.distance( Vector(ref.sx, ref.sy), Vector(touch.osx, touch.osy)) if distance > self.double_tap_distance: continue if touch.is_mouse_scrolling or ref.is_mouse_scrolling: continue touch_button = None if 'button' in touch.profile: touch_button = touch.button if touch_button != ref_button: continue touch.double_tap_distance = distance return touch
def process(self, events): if self.double_tap_distance == 0 or self.double_tap_time == 0: return events # first, check if a touch down have a double tap for etype, touch in events: if not touch.is_touch: continue if etype == 'begin': double_tap = self.find_double_tap(touch) if double_tap: touch.is_double_tap = True tap_time = touch.time_start - double_tap.time_start touch.double_tap_time = tap_time distance = double_tap.double_tap_distance touch.double_tap_distance = distance # add the touch internally self.touches[touch.uid] = (etype, touch) # second, check if up-touch is timeout for double tap time_current = time() to_delete = [] for touchid in self.touches.keys(): etype, touch = self.touches[touchid] if etype != 'end': continue if time_current - touch.time_start < self.double_tap_time: continue to_delete.append(touchid) for touchid in to_delete: del self.touches[touchid] return events