Forum Archive

Hi there,

I am using the Gestures library from mikaelho (github)

I am trying to get the gesture recogizer to work to simulate turning a dial, but i can't seem to figure out how.

You can see my attempts including commented:

def tempo_knob(gest_data):
  #print(dir(gest_data))
  print(gest_data.recognizer)
  #print(gest_data.rotation)
  print('yeeep')

# [Gestures.UP, Gestures.DOWN, Gestures.LEFT, Gestures.RIGHT]
Gestures().add_swipe(knob1, tempo_knob, )


g = Gestures()

#g.recognize_simultaneously = lambda gr, other_gr: gr == Gestures.SWIPE and other_gr == Gestures.ROTATE

#g.add_swipe(knob1, tempo_knob, [Gestures.UP, Gestures.DOWN, Gestures.LEFT, Gestures.RIGHT])

Can anyone help how I may:

Capture both swiping in any direction (and knowing what direction it was swiped), as well as rotating.

I was able to get rotation when it was only g.add_rotate()

Any help would be greatly appreciated

are you thinking of a two finger gesture? standard rotate is a two finger gesture.
for a circular knob, I think you just want regular drag type gesture, where you record the delta-angle (relative to center of knob), and add that to the current rotation value.

Plese find below a very straight-forward translation of my understanding of what you are after.

#coding: utf-8
from ui import *
from gestures import *

v = View(background_color='white')
v.present('sheet')

b = Label(background_color='grey', text_color='white', alignment= ALIGN_CENTER, center=(v.center[0], v.bounds[3]/2-v.y))
v.add_subview(b)

current_rotation = 0

def rotation_handler(data):
  global current_rotation
  if data.state == Gestures.CHANGED:
    b.transform = Transform.rotation(current_rotation + data.rotation)    
  if data.state == Gestures.ENDED:
    current_rotation += data.rotation

def swipe_handler_up(data):
  b.text = 'UP'

def swipe_handler_right(data):
  b.text = 'RIGHT'

g = Gestures()
g.add_rotation(v, rotation_handler)

g.add_swipe(v, swipe_handler_up, Gestures.UP)
g.add_swipe(v, swipe_handler_right, Gestures.RIGHT)
# Etc. for down, left

@JonB

You are definitely right about the standard drag gesture, in the app I am making I wanted to make it optional with that I am fully aware of the rotation gesture being two fingers.

I am helping a friend if mine learn Python, and with that Pythonista.

He decided to take on a difficult project for a beginner - a metronome, that being said the drag is easier to deal with as an end user but then an accidental touch may cause an unwanted change in tempo, for instance.

I am setting up the more advanced ui elements for him as he isn't ready for it yet, and using it as an excuse to learn gestures in general, never had a need before.

@mikael,

Yes that is exactly what I was looking for! Thank you!

I assume if I wanted to implement the suggestion from @JonB - which I do now, I assume I would use the pan gesture? I am assuming this since I am able to read the velocity and calculate the direction, at least I think based on the data it reports.

Ill try to work it out on my own either way but if I am on the wrong track it may save me some time :)

Thank you again, this example REALLY helps clarify your lib.

@reticulated, yes, pan is your friend for dragging things.