draw ui.Path within the coordinate system of a node

[zipit]

Hi,

I do not really understand how the frame of an ui.Path object works. If have cooked up a small scene that illustrates the problems I have. I am trying to draw an ui.Path that is matching points (coordinates) in the frame of a node. It seems that an ui.Path is always being centered on the center of the presenting ShapeNode.

So my question is: How do I draw a path which is not centered on the center of its presenting ShapeNode - for example one that only lives in the x+y+ frame ? I would like to be able to actually draw within the coordinates system/frame of the presenting ShapeNode .

Cheers,
zipit

from scene import *

class MyScene (Scene):
    def setup(self):
        sx, sy = self.size.w * .5, self.size.h * .5
        # I would expect the white rect to have its lower left corner 
        # at the center of the screen. But it does not, it is sitting
        # on the origin of the node, x and y seem to have no effect.
        self.white = ShapeNode(ui.Path.rect(sx, sy, 200, 200), 
                               parent=self,
                               position=(0, 0))
        # a reference rect as our white rect is kinda off screen
        self.red = ShapeNode(ui.Path.rect(0, 0, 150, 150), 
                             parent=self,
                             fill_color = 'red',
                             position=(sx, sy)) 
        # Here I would expect a line from the right top corner
        # of the red rect going to a point (25, 50) in the 
        # top right direction. But again the path is centered
        # on the node and also the y coordinate is being inverted.
        path = ui.Path()
        path.move_to(75,  75)
        path.line_to(sx + 100, sy + 125)
        path.line_width = 3
        self.cyan = ShapeNode(path, 
                              parent=self.red,
                              stroke_color='cyan',
                              position=(0, 0))
         

if __name__ == '__main__':
    run(MyScene(), show_fps=False)```

[mikeno]

My last issue is that the drawing doesn’t refresh even when I call explicitly drawTest() as you can see in the example below:

import ui

class my(ui.View):
    
    def __init__(self, *args, **kwargs):
        self.factor = .5

    def draw(self):
        print('draw()')
        self.drawTest()

    def drawTest(self):
        print('drawTest()')
        print('%.1f' % (self.factor))
        w,h = ui.get_screen_size()
        path1 = ui.Path()
        path1.line_width = 3
        ui.set_color('red')
        path1.move_to(100*self.factor,100*self.factor)
        path1.line_to(200*self.factor,100*self.factor)
        path1.line_to(100*self.factor,200*self.factor)
        path1.close()
        path1.fill()
        path2 = ui.Path()#.rect(0,0,w,h)
        path2.line_width = 3
        ui.set_color('blue')
        path2.move_to(300*self.factor,100*self.factor)
        path2.line_to(400*self.factor,100*self.factor)
        path2.line_to(300*self.factor,200*self.factor)
        path2.close()
        path2.fill()
        
    def touch_began(self, touch):
        print('touch_began()')
        self.factor += .5
        self.drawTest()
        
    def will_close(self):
        print('will_close()')
        
v = my()
v.present('fullscreen',hide_title_bar=True)

It redraws only when I turn the iPad, could you please tell me how I can force the refresh with the right zoom factor?

[cvp]

@mikeno start from

import ui

class my(ui.View):
    
    def __init__(self, *args, **kwargs):
        self.w,self.h = ui.get_screen_size()
        iv = ui.ImageView(name='iv')
        iv.frame = (0,0,self.w,self.h)
        self.add_subview(iv)
        self.factor = .5
        self.update_interval = 1

    def update(self):
        with ui.ImageContext(self.w,self.h) as ctx:
          path1 = ui.Path()
          path1.line_width = 3
          ui.set_color('red')
          path1.move_to(100*self.factor,100*self.factor)
          path1.line_to(200*self.factor,100*self.factor)
          path1.line_to(100*self.factor,200*self.factor)
          path1.close()
          path1.fill()
          path2 = ui.Path()#.rect(0,0,w,h)
          path2.line_width = 3
          ui.set_color('blue')
          path2.move_to(300*self.factor,100*self.factor)
          path2.line_to(400*self.factor,100*self.factor)
          path2.line_to(300*self.factor,200*self.factor)
          path2.close()
          path2.fill()
          ui_image = ctx.get_image()
        self['iv'].image = ui_image
        
    def touch_began(self, touch):
        self.factor += .5
        
    def will_close(self):
        print('will_close()')
        
v = my()
v.present('fullscreen',hide_title_bar=True)

[mikeno]

Whao, I’m impressed, thank you!
But I don’t understand why it doesn’t work in my last example

[cvp]

@mikeno said:

But I don’t understand why it doesn’t work in my last example

Sincerely, me neither 😂

[cvp]

@mikeno just to show how it is easy to use @mikael 's gestures module, use two fingers to pinch

import ui
from gestures import *

class my(ui.View):
    
    def __init__(self, *args, **kwargs):
        self.w,self.h = ui.get_screen_size()
        iv = ui.ImageView(name='iv')
        iv.frame = (0,0,self.w,self.h)
        self.add_subview(iv)
        self.factor = .5
        #self.update_interval = 1
        self.pinch = pinch(iv,self.did_pinch)
        self.update()

    def update(self):
        with ui.ImageContext(self.w,self.h) as ctx:
          path1 = ui.Path()
          path1.line_width = 3
          ui.set_color('red')
          path1.move_to(100*self.factor,100*self.factor)
          path1.line_to(200*self.factor,100*self.factor)
          path1.line_to(100*self.factor,200*self.factor)
          path1.close()
          path1.fill()
          path2 = ui.Path()#.rect(0,0,w,h)
          path2.line_width = 3
          ui.set_color('blue')
          path2.move_to(300*self.factor,100*self.factor)
          path2.line_to(400*self.factor,100*self.factor)
          path2.line_to(300*self.factor,200*self.factor)
          path2.close()
          path2.fill()
          ui_image = ctx.get_image()
        self['iv'].image = ui_image
        
    def did_pinch(self, data):
        self.factor = data.scale
        self.update()
        
    def will_close(self):
        print('will_close()')
        
def pinch_handler(data):
        print(data)
        
v = my()
v.present('fullscreen',hide_title_bar=True)

[mikeno]

Thx cvp but I don’t know how to download a module into Pythonista

[cvp]

@mikeno use, and keep for the future, this script

import requests
import os
url = 'https://raw.githubusercontent.com/mikaelho/pythonista-gestures/master/gestures.py'
response = requests.get(url)
content = str(response.content.decode('utf-8'))
file_path = os.path.expanduser('~/Documents/site-packages/gestures.py')
with open(file_path,mode='wt',encoding='utf-8') as fil:
    fil.write(content)

[mikeno]

Super, thank you

[ccc]

@cvp said:

content = str(response.content.decode('utf-8'))

text = response.text

[cvp]

@ccc you're right here with a script but I'm sure that I had to use decode in the past for some web page containing special characters...But never mind, your code is better.

[mikael]

@mikeno, your script did not redraw on touch because your method did not get called with the drawing context that draw does. To make it work, trigger the draw with self.set_needs_display().

For installing stuff, recommend taking the time to install stash, for pip install support.

But keep @cvp’s install script around, most of the little things we build do not end up in pip/PyPI.

[cvp]

@mikael said:

To make it work, trigger the draw with self.set_needs_display().

Forgotten, halala this too old memory 😢

[rajputaman04]

I do have a follow up question though. Is it possible to access the points of a path after it has been created? edit: and with access I mean read them.

[mikael]

@rajputaman04, unfortunately no.