I'm working through the Kivy tutorial, programming guide, and find the following code is not actually printing the button position anywhere, as far as I can tell---that is, the btn_pressed() method doesn't seem to do anything.
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.button import Button
from kivy.uix.boxlayout import BoxLayout
from kivy.properties import ListProperty
class RootWidget(BoxLayout):
def __init__(self, **kwargs):
super(RootWidget, self).__init__(**kwargs)
self.add_widget(Button(text='btn 1'))
cb = CustomBtn()
cb.bind(pressed=self.btn_pressed)
self.add_widget(cb)
self.add_widget(Button(text='btn 2'))
def btn_pressed(self, instance, pos):
print ('pos: printed from root widget: {pos}'.format(pos=pos))
class CustomBtn(Widget):
pressed = ListProperty([0, 0])
def on_touch_down(self, touch):
if self.collide_point(*touch.pos):
self.pressed = touch.pos
# we consumed the touch. return False here to propagate
# the touch further to the children.
return True
return super(CustomBtn, self).on_touch_down(touch)
def on_pressed(self, instance, pos):
print ('pressed at {pos}'.format(pos=pos))
class TestApp(App):
def build(self):
return RootWidget()
if __name__ == '__main__':
TestApp().run()
Does anyone have any hints or ideas why this isn't working? Is this the intended behavior and I missed something or is there an error in the tutorial?
Specifically, while the instructions above produce buttons that can be clicked and flash---there doesn't seem to be any output corresponding to the method:
def btn_pressed(self, instance, pos):
print ('pos: printed from root widget: {pos}'.format(pos=pos))
Maybe it's printing black on black?
The seemingly blank, unlabeled spot in the middle is the button that accepts location and prints location to the console. I was clicking on the buttons labeled "btn" and didn't notice this place existed.
This part of the tutorial is demonstrating how you can make custom buttons that do stuff precisely like this. It would be more clear if this were labeled, but that should be doable by looking at the API.
Anyway, the code is working as expected.
Related
I have installed kivy on my Ubuntu and connected a touch screen, but when I touch the screen kivy doesn't detect that.
To detect mouseclicks is no problem, just touch isn't working.
I already did the changes in config.ini:`
mouse = mouse;
mtdev_%(name)s = probesysfs,provider=mtdev; hid_%(name)s = probesysfs,provider=hidinput
Thats my code:
from kivy.app import App
from kivy.uix.widget import Widget
class TouchInput(Widget):
def on_touch_down(self, touch):
print(touch)
def on_touch_move(self, touch):
print(touch)
def on_touch_up(self, touch):
print("RELEASED!",touch)
class SimpleKivy4(App):
def build(self):
return TouchInput()
if name == "main":
SimpleKivy4().run()
Does anybody have a other idea why kivy doesn't detect my touch input?
Thank you in advance.
While you've defined your on_touch_*(self, touch) function, it's not enough to define it. The Window module has a on_touch_* method, but it is currently bound to None. It is the Window module, not your own classes/widgets, that manages the whole window of your app, that calls the callbacks such as motion and touch. Under the docs for input.motionevent, it has the following on how to listen (use your callback) for a motion/touch event:
def on_touch_down(self, touch):
# Receives a motion event with the [pos] profile
pass
Window.bind(on_touch_down=on_touch_down)
You're missing the Window.bind(window_method=my_function) call.
I found this piece of code:
from kivy.app import App
from kivy.lang import Builder
from kivy.core.window import Window
from kivy.uix.boxlayout import BoxLayout
class Test(BoxLayout):
def __init__(self, **kwargs):
super(Test, self).__init__(**kwargs)
Window.bind(on_touch_down=self.window_on_touch_down)
def window_on_touch_down(self, *args):
print(args)
# scrolling the wheel down will give <MouseMotionEvent button="scrollup"
if '<MouseMotionEvent button="scrollup"' in args:
print('hello')
class TestApp(App):
def build(self):
return Test()
if __name__ == '__main__':
TestApp().run()
and while it prints the scrollup motion I can't use it... args has the string in it but the if doesn't work and "hello" isn't printed... anybody know why?
What you see in the prints are python objects not strings.
So you can't just check for a string.
A better way to get what you want is to check what button produces the MouseMotionEvent
def window_on_touch_down(self, window, mouse_event):
# scrolling the wheel down will give <MouseMotionEvent button="scrollup"
if mouse_event.button == "scrollup":
print('hello')
I have a button which was made in python file and I have been trying to make it so it changes screens from one to another.
def callback(instance):
print("Test 1")
sm = ScreenManager()
sm.add_widget(ScreenTwo(name="ScreenTwo"))
print("Test2")
class ScreenOne(Screen):
def on_enter(self):
self.add_widget(ImageURLButton(source=icon2, size=(100,100), size_hint=(0.1, 0.1), on_press=callback, pos_hint={"x":0.90, "top":1.0}))
class ScreenTwo(Screen):
pass
class ScreenManagement(ScreenManager):
pass
When I do click the button all it does it prints "Test1" and "Test2" without it changing the screen. Sorry if this is really obvious to others but I do not know how to fix it, could anyone help me please?
Would be better if you posted a MCVE, but I made one myself. Here is how it can be done:
from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.screenmanager import ScreenManager, Screen
def callbackTo2(instance):
sm.current="ScreenTwo"
def callbackTo1(instance):
sm.current="ScreenOne"
class ScreenOne(Screen):
def __init__(self, *args):
super(ScreenOne, self).__init__(name='ScreenOne')
self.add_widget(Button(text='Switch To Screen Two', size_hint=(0.1, 0.1), on_press=callbackTo2, pos_hint={"x":0.90, "top":1.0}))
class ScreenTwo(Screen):
def __init__(self, *args):
super(ScreenTwo, self).__init__(name='ScreenTwo')
self.add_widget(Button(text='Switch To Screen One', size_hint=(0.1, 0.1), on_press=callbackTo1, pos_hint={"x":0.90, "top":1.0}))
sm = ScreenManager()
class ScreenPlayApp(App):
def build(self):
sm.add_widget(ScreenOne())
sm.add_widget(ScreenTwo())
return sm
if __name__ == '__main__':
app = ScreenPlayApp()
app.run()
Note that there is only one ScreenManager instance, all the screens can be added to the ScreenManager initially, and screens are switched by using sm.current=. Also, you can build your Screen in its __init__() method. Using the on_enter causes the members of the screen to be rebuilt each time the screen is displayed. Also, you cannot use both 'size' and 'size_hint' for the same widget unless you are setting 'size_hint' to 'None'.
on implementing below code every time last widget gets activated
and after that each and every widget gets activated
please solve this
on implementing below code every time last widget gets activated
and after that each and every widget gets activated
please solve this
on implementing below code every time last widget gets activated
and after that each and every widget gets activated
please solve this
on implementing below code every time last widget gets activated
and after that each and every widget gets activated
please solve this
on implementing below code every time last widget gets activated
and after that each and every widget gets activated
please solve this
`
from pieces import matrix
from kivy.app import App
from kivy.graphics import Color,Rectangle
from kivy.core.window import Window
from kivy.uix.widget import Widget
from kivy.uix.image import Image
from kivy.clock import Clock
class Sprite(Image):
def __init__(self,size=None,**kwargs):
super(Sprite, self).__init__(**kwargs)
if size==None:
self.size = self.texture_size
else:self.size=size
class Basket(Widget):
def __init__(self,source,pos,name,**kwargs):
super(Basket,self).__init__(**kwargs)
self.speed=4
self.name=name
self.image=Sprite(source=source,pos=pos,size=[100,100])
self.add_widget(self.image)
self.size=self.image.size
print self.size
def update_y(self,a):
final=a*100+50
if self.image.center_y==final:return True
elif self.image.center_y<final:self.image.center_y+=self.speed
else:self.image.center_y-=self.speed
return False
def update_x(self,a):
final=a*100+50
if self.image.center_x==final:return True
elif self.image.center_x<final:self.image.center_x+=self.speed
else:self.image.center_x-=self.speed
return False
def on_touch_down(self,touch):
if touch.grab_current is self:
print self.name
class Game(Widget):
def __init__(self,**kwargs):
super(Game,self).__init__(**kwargs)
self.matrix=matrix()
self.add_widget(Sprite(source='images/gray.jpg'))
for i in range(2):
self.ids[str(i)]=Basket(source='images/basket.jpg',name=str(i),pos=(i*100,i*100))
self.add_widget(self.ids[str(i)])
print i
# Clock.schedule_interval(self.update, 1.0/60.0)
# self.matrix.shuffle()
def update(self,ab):
if self.matrix.up:
if reduce(lambda a,i:self.ids[str(i)].update_y(self.matrix.y[i]) and a ,range(4),True):
self.matrix.shuffle()
else:
if reduce(lambda a,i:self.ids[str(i)].update_x(self.matrix.x[i]) and a,range(4),True):
self.matrix.shuffle()
def on_touch_down(self,touch):
print touch.grab(self)
class GameApp(App):
def build(self):
g=Game(size=(400,400))
Window.size=g.size
return g
GameApp().run()
`
Kivy doesn't perform touch collision by default, so that widgets can interact with touches that do not collide with them (since the widget arrangement is not necessarily the same as the gui touch arrangement).
You can just perform the collision check yourself:
def on_touch_down(self, touch):
if self.collide_point(*touch.pos):
do_stuff()
I'm just starting off with Kivy and it's different to what I'm used to, apologies if I'm making stupid mistakes!
Right now I'm trying to create an app that does the following:
Allows creation of Nodes (ellipses for now).
Allows the user to position the nodes by dragging.
Allows the user to connect the nodes with a line.
So far I've achieved the first, and the second somewhat.
Right now my dragging is not working too well. If I move the mouse too quickly it cancels the move method (as it is no longer in contact). Is there a better way to produce dragging or do I just increase the refresh rate (if so how?).
def on_touch_move(self, touch):
if self.collide_point(touch.x, touch.y):
self.pos=[touch.x-25, touch.y-25]
I've tried using Buttons instead, using the on_press method to track the moving better. However now I'm having difficulty updating the position of the button (mostly just syntax).
class GraphNode(Button):
background_disabled_down=1
background_disabled_normal=1
def moveNode(self):
with touch:
self.pos=[touch.x-25, touch.y-25]
I have no idea how to use the touch value, and keep getting an array of errors. (Obviously the current attempt doesn't work, I just thought it was funny).
As you could probably tell, I also don't know how to get rid of the button graphics, as I want to use the ellipse. As an added bonus if someone could show me how to change the colour of the ellipse on button press that would be cool!
The kv file:
<GraphNode>:
size: 50, 50
canvas:
Ellipse:
pos: self.pos
size: self.size
on_press:
root.moveNode()
I want to be able to use the touch information to update the position, but don't know how to implement it here.
Full core python code:
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.button import Button
from kivy.properties import NumericProperty, ReferenceListProperty,\
ObjectProperty
from kivy.graphics import Color, Ellipse, Line
class GraphInterface(Widget):
node = ObjectProperty(None)
class GraphApp(App):
def build(self):
node = GraphNode()
game = GraphInterface()
createNodeButton = Button(text = 'CreateNode', pos=(100,0))
createEdgeButton = Button(text = 'CreateEdge')
game.add_widget(createNodeButton)
game.add_widget(createEdgeButton)
def createNode(instance):
game.add_widget(GraphNode())
print "Node Created"
def createEdge(instance):
game.add_widget(GraphEdge())
print "Edge Created"
createNodeButton.bind(on_press=createNode)
createEdgeButton.bind(on_press=createEdge)
return game
class GraphNode(Button):
def moveNode(self):
with touch:
self.pos=[touch.x-25, touch.y-25]
#def onTouchMove(self, touch):
# if self.collide_point(touch.x, touch.y):
# self.pos=[touch.x-25, touch.y-25]
pass
class GraphEdge(Widget):
def __init__(self, **kwargs):
super(GraphEdge, self).__init__(**kwargs)
with self.canvas:
Line(points=[100, 100, 200, 100, 100, 200], width=1)
pass
if __name__ == '__main__':
GraphApp().run()
If you need any other info, or anything is unclear, please let me know!
Edit: Second question moved to: Creating a dynamically drawn line in Kivy.
First, you should read up on touch events in Kivy. Of particular interest here is the section on grabbing touch events. Basically, you can "grab" a touch to ensure that the grabbing widget will always receive further events from that touch - in other words, the on_touch_move and on_touch_up following that touch event will be sent to your widget.
Basic example:
class MyWidget(Widget):
def on_touch_down(self, touch):
if self.collide_point(*touch.pos):
touch.grab(self)
# do whatever else here
def on_touch_move(self, touch):
if touch.grab_current is self:
# now we only handle moves which we have grabbed
def on_touch_up(self, touch):
if touch.grab_current is self:
touch.ungrab(self)
# and finish up here
But, even better! If you want to be able to drag widgets around, Kivy already has that: Scatter.
Just wrap your widget in a Scatter and you can drag it around. You can also use multitouch to rotate and scale a Scatter, but you can easily disable that (kv):
FloatLayout:
Scatter:
do_scale: False
do_rotation: False
MyWidget:
Side note - this is incorrect:
class GraphNode(Button):
background_disabled_down=1
background_disabled_normal=1
background_disabled_down and background_disabled_normal are Kivy properties - you should set those values in __init__.
Force these values:
class GraphNode(Button):
def __init__(self, **kwargs):
super(GraphNode, self).__init__(background_disabled_down='',
background_disabled_normal='', **kwargs)
Suggest these values (better option):
class GraphNode(Button):
def __init__(self, **kwargs):
kwargs.setdefault('background_disabled_down', '')
kwargs.setdefault('background_disabled_normal', '')
super(GraphNode, self).__init__(**kwargs)
Finally, note that these properties are filenames pointing to the images used for the disabled Button. If you remove these values, and disable your button, it will draw no background whatsoever.