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pythonkivykivy-language

Getting widget/item ids within TabbedPanel

I have created a simple App in Kivy that has tabs and within each tab I only have a few widgets. Prior to adding the tabbedPanel I had no issue reaching each widget through "ids". For example:

app.root.ids.mylabel1.ids.mylabel2.content

However, now that I have added widgets within the tabbedPanel they become unreachable for me. The tabbedPanel "blocks" me and contains no ids: For example my .kv-file has a button:

<SelectableButton>:
    text: self.button_text
    id: SelectableButton_id
    canvas.before:
        Color:
            rgba: (0, 0.517, 0.705, 1) if self.selected else (0, 0.517, 0.705, 1)
        Rectangle:
            pos: self.pos
            size: self.size
    state: self.btnState
    on_release:
        print(app.root.content.ids)

returns an empty dict. I followed the guidance for tabbedPanel and found that it only has one "children" which is ".content". But still I am not able to reach any widgets within this tab.

Am I going about this the wrong way? Or can anyone guide me to how to access the widgets within a certain tab.

Solution

  • With Kivy TabbedPanel, you can reference the ids using app.root.ids.id-name or self.ids.id-name e.g. app.root.ids.label3.text or self.ids.label3.text because when your kv file is parsed, kivy collects all the widgets tagged with id’s and places them in this self.ids dictionary type property.

    Example

    main.py

    from kivy.app import App
from kivy.uix.tabbedpanel import TabbedPanel
from kivy.lang import Builder
from kivy.uix.label import Label
from kivy.uix.button import Button

Builder.load_string("""

<Test>:
    size_hint: .5, .5
    pos_hint: {'center_x': .5, 'center_y': .5}
    do_default_tab: False

    TabbedPanelItem:
        text: 'first tab'
        Label:
            text: 'First tab content area'

    TabbedPanelItem:
        id: tab2
        text: 'tab2'

        BoxLayout:
            id: box1
            orientation: 'vertical'

            Label:
                id: label1
                text: 'Second tab content area'
            Button:
                id: button1
                text: 'Button that does nothing'

            BoxLayout:
                id: box2
                orientation: 'vertical'

                Label:
                    id: label2
                    text: 'Label 2'

                BoxLayout:
                    id: box3
                    orientation: 'vertical'

                    Button:
                        id: button2
                        text: 'Button 2'
                    Label:
                        id: label3
                        text: 'Label 3'

    TabbedPanelItem:
        text: 'tab3'
        RstDocument:
            text:
                '\\n'.join(("Hello world", "-----------",
                "You are in the third tab."))

""")


class Test(TabbedPanel):

    def __init__(self, **kwargs):
        super(Test, self).__init__(**kwargs)
        print(f"\nself.ids.items():")
        for key, val in self.ids.items():
            if isinstance(val, Label) or isinstance(val, Button):
                print(f"\tkey={key}, val={val}, val.text={val.text}")
            else:
                print(f"\n\tkey={key}, val={val}")

        print(f"\nself.ids.label3.text={self.ids.label3.text}")


class TabbedPanelApp(App):
    def build(self):
        return Test()


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

    Output

    Result