Pure Python gestures

mikael

@stephen, the original request for ”pull to refresh” was covered earlier with one line of ”math”. What are you trying to achieve here? Spring force? Coulomb effect?

If you like scene and like to play with forces, you could look at SpriteKit - but that would not be ”rolling your own”.

stephen

@mikael its ok but yes i was trying to acheive a spring like constraint. but ill go ahead a put it to the side for now. thanks for the reply.

Drizzel

I‘m trying to double tap on a TableViewCell without actually selecting it, but it should still be selectable on a single tap. How would I go about doing this?

Let’s assume I have this code:

import ui
import gestures

def double_tap(data):
	print('double tapped row', data.view.row)
def tap(data):
	print('tapped', data.view.row)
def long_press(data):
	print('long pressed', data.view.row)

def tableview_cell_for_row(tableview, section, row):
	data = tableview.data_source.items[row]
	cell = ui.TableViewCell('subtitle')
	cell.text_label.text = data
	cell.row = row
	gestures.doubletap(cell, double_tap)
	#gestures.tap(cell, tap, number_of_touches_required = 1)
	#gestures.long_press(cell, long_press, minimum_press_duration = .2)
	
	return cell
	
class Delegate():
	def tableview_did_select(self, tableview, section, row):
		print('selected row', row)

tv = ui.TableView()
tv.delegate = Delegate()
tv.data_source = ui.ListDataSource([str(x) for x in range(5)])
tv.data_source.delete_enabled = False
tv.data_source.tableview_cell_for_row = tableview_cell_for_row
tv.frame = (tv.frame[0], tv.frame[1], 400, 400)

tv.present(style = 'sheet')

stephen

@Drizzel said:

I‘m trying to double tap on a TableViewCell without actually selecting it, but it should still be selectable on a single tap. How would I go about doing this?

Let’s assume I have this code:

import ui
import gestures

def double_tap(data):
	print('double tapped row', data.view.row)
def tap(data):
	print('tapped', data.view.row)
def long_press(data):
	print('long pressed', data.view.row)

def tableview_cell_for_row(tableview, section, row):
	data = tableview.data_source.items[row]
	cell = ui.TableViewCell('subtitle')
	cell.text_label.text = data
	cell.row = row
	gestures.doubletap(cell, double_tap)
	#gestures.tap(cell, tap, number_of_touches_required = 1)
	#gestures.long_press(cell, long_press, minimum_press_duration = .2)
	
	return cell
	
class Delegate():
	def tableview_did_select(self, tableview, section, row):
		print('selected row', row)

tv = ui.TableView()
tv.delegate = Delegate()
tv.data_source = ui.ListDataSource([str(x) for x in range(5)])
tv.data_source.delete_enabled = False
tv.data_source.tableview_cell_for_row = tableview_cell_for_row
tv.frame = (tv.frame[0], tv.frame[1], 400, 400)

tv.present(style = 'sheet')

i believe you might wand def tableview_cell_for_row(tableview, section, row): as a method of class Delegate instead of a global function.

stephen

@Drizzel
im sure there is a much simpler way but...

why not have a state checker give x time to look for a second tap before executing functionality for a single tap? possibly a decorator?

mikael

@Drizzel, below works to separate the two gestures, but we lose the visual feedback for the tap selection, you would need to implement that yourself.

Better would be to find the built-in tap and give our doubletap preference over it, but I could not (yet...?) find it on the tableview, cell, content view, or the label.

import ui
import gestures

def double_tap(data):
    print('double tapped row', data.view.row)
    
def tap(data):
    print('tapped', data.view.row)
    
def tableview_cell_for_row(tableview, section, row):
    data = tableview.data_source.items[row]
    cell = ui.TableViewCell('subtitle')
    cell.selectable = False
    cell.text_label.text = data
    cell.row = row
    doubler = gestures.doubletap(cell, double_tap)
    tapper = gestures.tap(cell, tap)
    doubler.before(tapper)
    return cell
    
class Delegate():
    def tableview_did_select(self, tableview, section, row):
        print('selected row', row)

tv = ui.TableView(allows_selection=False)
tv.delegate = Delegate()
tv.data_source = ui.ListDataSource([str(x) for x in range(5)])
tv.data_source.delete_enabled = False
tv.data_source.tableview_cell_for_row = tableview_cell_for_row

tv.present('fullscreen')

Drizzel

@mikael thanks, that works. I just change the cell‘s background color to lightgrey for visual feedback

Drizzel

@stephen True, I corrected it :) The code was a bit rushed 🤷‍♂️

stephen

awesome 😎🤓😊

mikael

@Drizzel, here’s a version that supports both the doubletap and regular row selection.

import ui
import gestures

def double_tap(data):
    print('double tapped row', data.view.row)
    
def tableview_cell_for_row(tableview, section, row):
    data = tableview.data_source.items[row]
    cell = ui.TableViewCell('subtitle')
    cell.text_label.text = data
    cell.row = row
    doubler = gestures.doubletap(cell, double_tap)
    doubler.recognizer.delaysTouchesBegan = True
    return cell
    
class Delegate():
    def tableview_did_select(self, tableview, section, row):
        print('selected row', row)

tv = ui.TableView()
tv.delegate = Delegate()
tv.data_source = ui.ListDataSource([str(x) for x in range(5)])
tv.data_source.delete_enabled = False
tv.data_source.tableview_cell_for_row = tableview_cell_for_row

tv.present('fullscreen')

Anxietier

hi, i found another bug, after i use 5 fingers to switch app and get back, multi-touch would be not working

cvp

@mikael Do you think it would be possible to use you gestures module on an objectiveC object?

I want to add gestures on a SceneView object, but functions like tap require their view parameter as an object having objc_instance property (see UIGestureRecognizerDelegate init).

cvp

@mikael I solved it with

	def scene_view_tap(self,sender):
		location = self.recognizer.locationInView_(self.scene_view)
		node = self.scene_view.hitTest_options_(location,None)
		print(node)

.
.
.
		self.gesture_recognizer_target = ui.Button()
		self.gesture_recognizer_target.action = self.scene_view_tap
		UITapGestureRecognizer = ObjCClass('UITapGestureRecognizer')
		self.recognizer = UITapGestureRecognizer.alloc().initWithTarget_action_(self.gesture_recognizer_target, sel('invokeAction:')).autorelease()
		scene_view.addGestureRecognizer_(self.recognizer)
		self.scene_view = scene_view

mikael

@cvp, forgot to advertise earlier that the latest version of gestures in the ui3 module accepts ObjC views in addition to ui module views.

from ui3.gestures import *

tap(objc_view, handler)

cvp

@mikael thanks, I'll try

Édit: done, ok
Re-Edit: marvelous module

itibettravel

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