CODEWITHSUNDEEP
pythonwidgetkivy
MoriB
MoriB

Reputation: 311

Kivy : how to get widget by id (without kv)

Let's say I define on the fly in Kivy a few widgets (buttons) and dynamically assign their id. I'm not using kv language in this use case. I can keep a reference of a widget id without keeping track of the widget itself : then I'd like to access the widget through its id. Can I do something like "get widget by id" ? (If I had defined the widget in a kv file, I could have used self.ids.the_widget_id to access the widget itself through its id)

Upvotes: 6

Views: 12855

Answers (3)

Tomek Krasuski
Tomek Krasuski

Reputation: 41

You can change properties of each widget using ids:

self.ids['order_number'].text='S1212'

Upvotes: 0

user3058051
user3058051

Reputation: 21

You can retrieve the widget using directly the ids. For example in your code you can modify the Button text with the following snippet:

self.ids.2.ids.3.ids.1.text = '!!!!'

Upvotes: 2

Nykakin
Nykakin

Reputation: 8747

Kivy widgets make tree structure. Children of any widget are avaiable through children atribute. If you want, you can keep reference only to root window and then iterate over it's widgets using walk method:

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button 

class MyWidget(BoxLayout):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)

        button = Button(text="...", id="1")
        button.bind(on_release=self.print_label)

        l1 = BoxLayout(id="2")
        l2 = BoxLayout(id="3")

        self.add_widget(l1)
        l1.add_widget(l2)             
        l2.add_widget(button)

    def print_label(self, *args):
        for widget in self.walk():
            print("{} -> {}".format(widget, widget.id))

class MyApp(App):
    def build(self):
        return MyWidget()

if __name__ == '__main__':
    MyApp().run()

walk() and walk_reverse() method were added to kivy.uix.widget.Widget in 1.8.1 version of Kivy. For older versions you need to recursively parse tree yourself:

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button 

class MyWidget(BoxLayout):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)

        button = Button(text="...", id="1")
        button.bind(on_release=self.print_label)

        l1 = BoxLayout(id="2")
        l2 = BoxLayout(id="3")

        self.add_widget(l1)
        l1.add_widget(l2)             
        l2.add_widget(button)

    def print_label(self, *args):
        children = self.children[:]
        while children:
            child = children.pop()
            print("{} -> {}".format(child, child.id))
            children.extend(child.children)

class MyApp(App):
    def build(self):
        return MyWidget()

if __name__ == '__main__':
    MyApp().run()

Upvotes: 3

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