How to use ScrollView in KV

[Abraham Francisco]

Its me, the alarm app guy. I'm on to my next implementation quest and I've decided I want to change out how I have to manually input the time in the 'alarmedit' page and be able to scroll through number selections to input your desired time.

I believe using ScrollView would be the answer, so I thought I'd use the kv example from the documentation and paste it in my code just to see it working in a conceptual manner first but I get this error:

   if current_property[:3] == 'on_':

 TypeError: 'NoneType' object is not subscriptable

What is this telling me? And before anything else, I'm going to most likely need three scrolls (1 for hrs, 1 for mins, and 1 for pm/am). Is it possible to have that many scrolls in one boxlayout?

I'm going for something like this:

The top half where the numbers can be scrolled by touch.

Here's my code. I only just threw the kv example from the doc in:

    from kivy.app import App

    from kivy.lang import Builder

    from kivy.clock import Clock

    from kivy.properties import StringProperty

    from kivy.uix.label import Label

    from kivy.uix.screenmanager import Screen

    from kivy.uix.image import Image

    from kivy.uix.behaviors import ToggleButtonBehavior

    import os

    from kivy.uix.popup import Popup

    from kivy.core.audio import SoundLoader

    

    from time import strftime

    

    kv = """

    <Home@Screen>:

        BoxLayout:

            orientation: 'vertical'

            MyClock:

                font_size: 50

                text: self.current_time

            Button:

                background_color: (128,0,0,.6)

                background_down: '(0, 0, .3, 1)'

                text: 'Set Alarm'

                on_press: root.manager.current = 'alarm_page'

    

    <AlarmPage@Screen>:

        GridLayout:

            rows: 4

            Button:

                text: 'Alarm 1'

                on_release: root.manager.current = 'edit1_page'

    

            Button:

                text: 'Alarm 2'

                on_release: root.manager.current = 'edit2_page'

            Button:

                text: 'Put alarms on this page'

                on_release: root.manager.current = 'home_page'

    

    <AlarmEdit>:

        BoxLayout:

            orientation: 'vertical'

            ScrollView:

                do_scroll_x: False

                do_scroll_y: True

    

                Label:

                    size_hint_y: None

                    height: self.texture_size[1]

                    text_size: self.width

                    padding: 2, 2

                    text:

                        'really some amazing text\n' * 10

            GridLayout:

                cols: 4  

                Label:

                    text: 'Set Time (00:00):'

                TextInput:

                    id: alarmtime

                    text: root.alarm_time

                ToggleButton:

                    text: 'AM'

                    group:'am/pm'

                    state: root.alarm_am_state

                    on_state: root.alarm_am_state = self.state

                ToggleButton:

                    text: 'PM'

                    group:'am/pm'

                    state: root.alarm_pm_state

                    on_state: root.alarm_pm_state = self.state

            Button:

                text: "Set Alarm"

                on_press: 

                    root.set_alarm()

                    root.manager.current = 'home_page'

    

    BoxLayout:

        ScreenManager:

            id: sm

            Home:

                name: 'home_page'

            AlarmPage:

                name: 'alarm_page'

            AlarmEdit:

                name: 'edit1_page'

            AlarmEdit:

                name: 'edit2_page'

        """

    

    

    class MyClock(Label):

        current_time = StringProperty(strftime("%I:%M:%S %p"))

    

        def __init__(self, **kwargs):

            Clock.schedule_interval(self.update_time, 1)

            super().__init__(**kwargs)

    

        def update_time(self, dt):

            self.current_time = strftime("%I:%M:%S %p")

            app = App.get_running_app()

            t1 = app.root.ids.sm.get_screen('edit1_page').alarm(self.current_time)

    

    

    class AlarmEdit(Screen):  # Moved to the screen

        alarm_time = StringProperty()

        alarm_am_state = StringProperty('down')  # set default values

        alarm_pm_state = StringProperty('normal')

        passed_alarm = StringProperty()

    

        def __init__(self, **kwargs):

            super().__init__(**kwargs)

            if os.path.isfile("alarm1_details.txt"):

                with open("alarm1_details.txt", "r") as f:

                    d = f.read().split(",")

                    self.alarm_time = d[0]

                    self.alarm_am_state = d[1]

                    self.alarm_pm_state = d[2]

    

        def set_alarm(self):

            self.alarm_time = self.ids.alarmtime.text

    

            with open("alarm1_details.txt", "w") as f:

                f.write(f"{self.ids.alarmtime.text},{self.alarm_am_state},{self.alarm_pm_state}")

    

        def alarm(self, current_time):

            am_pm = {'down': 'AM', 'normal': 'PM'}[self.alarm_am_state]

            a_time = f"{self.alarm_time}:00 {am_pm}"

    

            if a_time[1] == ':':

                a_time = "0" + a_time

    

            print(f"a: {a_time} ct: {current_time}")

            if a_time == current_time:

                popup = Popup(title='Alarm 1', content=Label(text=self.alarm_time), size_hint=(None, None), size=(400, 400))

                popup.open()

                sound = SoundLoader.load("fire-truck-air-horn_daniel-simion.wav")

                sound.play()

    

    

    class MyButton(ToggleButtonBehavior, Label, Image):

        def __init__(self, **kwargs):

            super(MyButton, self).__init__(**kwargs)

            self.source = 'atlas://data/images/defaulttheme/checkbox_off'

    

        def on_state(self, widget, value):

            if value == 'down':

                self.source = 'atlas://data/images/defaulttheme/checkbox_on'

            else:

                self.source = 'atlas://data/images/defaulttheme/checkbox_off'

    

    

    class MainApp(App):

        def build(self):

            return Builder.load_string(kv)

    

    

    if __name__ == "__main__":

        MainApp().run()

Thanks for the help yal!

[Robert Flatt]

   if current_property[:3] == 'on_':

 TypeError: 'NoneType' object is not subscriptable

What is this telling me?

Subscripting selects a subset of a list,  a list of list elements is selected with the [:3]  syntax, exactly what that sub list is any web Python tutorial will tell you.

"object not subscriptable" means whatever is to the left of the [:3] is not a list, so you can not get its subscript.

So "current_property" is not a list, to understand what a list is see any Python tutorial ;)

'NoneType' means that "current_property" has not been assigned a value, so it has no type.

So there is no list to subscript which is the error. A type might be list, int, float, etc. (...Python tutorial...).

To fix this you need to know what "current_property" does and if you want that behavior in your code, if you want it then you must assign it an appropriate value.

A good study project :)

[Elliot Garbus]

This kind of error can be difficult to find.  It is an error from the kv parser.  It can be a problem with indentation.

--
You received this message because you are subscribed to the Google Groups "Kivy users support" group.
To unsubscribe from this group and stop receiving emails from it, send an email to kivy-users+...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/kivy-users/7708cb23-16ee-4fee-84e7-e5b4a53ab377o%40googlegroups.com.

 

[Elliot Garbus]

Two subtle mistakes.   The need to escape the \n is what caused the problems.

 

<AlarmEdit>:
    BoxLayout:
        orientation: 'vertical'
        ScrollView:
            do_scroll_x: False
            do_scroll_y: True
            Label:
                size_hint_y: None
                height: self.texture_size[1]

                text_size: self.width, None                # Missing , the y value for size
                padding: 2, 2
                text:'really some amazing text\\n' * 50    # Need to escape the \n This is a string in a string.
…

 

 

From: Robert Flatt
Sent: Wednesday, August 12, 2020 12:20 PM
To: Kivy users support
Subject: [kivy-users] Re: How to use ScrollView in KV

 

   if current_property[:3] == 'on_':

--

[Elliot Garbus]

Yes,  You can put multiple scrollviews in one BoxLayout.

 

From: Abraham Francisco
Sent: Wednesday, August 12, 2020 11:56 AM
To: Kivy users support

--

You received this message because you are subscribed to the Google Groups "Kivy users support" group.
To unsubscribe from this group and stop receiving emails from it, send an email to kivy-users+...@googlegroups.com.

To view this discussion on the web visit https://groups.google.com/d/msgid/kivy-users/e2f64341-956f-4940-a676-08ff0937c254o%40googlegroups.com.