mirror of
https://github.com/liberatedsystems/openCom-Companion.git
synced 2024-11-30 09:10:36 +01:00
318 lines
10 KiB
Python
318 lines
10 KiB
Python
|
"""
|
||
|
|
Behaviors/Declarative
|
||
|
|
=====================
|
||
|
|
|
||
|
|
.. versionadded:: 1.0.0
|
||
|
|
|
||
|
|
.. raw:: html
|
||
|
|
|
||
|
|
<div style="position: relative; padding-bottom: 56.25%; height: 0; overflow: hidden; max-width: 100%; height: auto;">
|
||
|
|
<iframe
|
||
|
|
src="https://www.youtube.com/embed/_kiaJacLz8o"
|
||
|
|
frameborder="0"
|
||
|
|
allowfullscreen
|
||
|
|
style="position: absolute; top: 0; left: 0; width: 100%; height: 100%;">
|
||
|
|
</iframe>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
As you already know, the Kivy framework provides the best/simplest/modern
|
||
|
|
UI creation tool that allows you to separate the logic of your application
|
||
|
|
from the description of the properties of widgets/GUI components.
|
||
|
|
This tool is named `KV Language <https://kivy.org/doc/stable/guide/lang.html>`_.
|
||
|
|
|
||
|
|
But in addition to creating a user interface using the KV Language Kivy allows
|
||
|
|
you to create user interface elements directly in the Python code.
|
||
|
|
And if you've ever created a user interface in Python code, you know how ugly
|
||
|
|
it looks. Even in the simplest user interface design, which was created using
|
||
|
|
Python code it is impossible to trace the widget tree, because in Python code
|
||
|
|
you build the user interface in an imperative style.
|
||
|
|
|
||
|
|
Imperative style
|
||
|
|
----------------
|
||
|
|
|
||
|
|
.. code-block:: python
|
||
|
|
|
||
|
|
from kivymd.app import MDApp
|
||
|
|
from kivymd.uix.bottomnavigation import MDBottomNavigation, MDBottomNavigationItem
|
||
|
|
from kivymd.uix.label import MDLabel
|
||
|
|
from kivymd.uix.screen import MDScreen
|
||
|
|
|
||
|
|
|
||
|
|
class Example(MDApp):
|
||
|
|
def build(self):
|
||
|
|
screen = MDScreen()
|
||
|
|
bottom_navigation = MDBottomNavigation(
|
||
|
|
panel_color="#eeeaea",
|
||
|
|
selected_color_background="#97ecf8",
|
||
|
|
text_color_active="white",
|
||
|
|
)
|
||
|
|
|
||
|
|
data = {
|
||
|
|
"screen 1": {"text": "Mail", "icon": "gmail"},
|
||
|
|
"screen 2": {"text": "Discord", "icon": "discord"},
|
||
|
|
"screen 3": {"text": "LinkedIN", "icon": "linkedin"},
|
||
|
|
}
|
||
|
|
for key in data.keys():
|
||
|
|
text = data[key]["text"]
|
||
|
|
navigation_item = MDBottomNavigationItem(
|
||
|
|
name=key, text=text, icon=data[key]["icon"]
|
||
|
|
)
|
||
|
|
navigation_item.add_widget(MDLabel(text=text, halign="center"))
|
||
|
|
bottom_navigation.add_widget(navigation_item)
|
||
|
|
|
||
|
|
screen.add_widget(bottom_navigation)
|
||
|
|
return screen
|
||
|
|
|
||
|
|
|
||
|
|
Example().run()
|
||
|
|
|
||
|
|
.. image:: https://github.com/HeaTTheatR/KivyMD-data/raw/master/gallery/kivymddoc/bottom-navigation-styles-programming.png
|
||
|
|
:align: center
|
||
|
|
|
||
|
|
Take a look at the above code example. This is a very simple UI. But looking
|
||
|
|
at this code, you will not be able to figure the widget tree and understand
|
||
|
|
which UI this code implements. This is named imperative programming style,
|
||
|
|
which is used in Kivy.
|
||
|
|
|
||
|
|
Now let's see how the same code is implemented using the KV language,
|
||
|
|
which uses a declarative style of describing widget properties.
|
||
|
|
|
||
|
|
Declarative style with KV language
|
||
|
|
----------------------------------
|
||
|
|
|
||
|
|
.. code-block:: python
|
||
|
|
|
||
|
|
from kivy.lang import Builder
|
||
|
|
|
||
|
|
from kivymd.app import MDApp
|
||
|
|
|
||
|
|
|
||
|
|
class Test(MDApp):
|
||
|
|
def build(self):
|
||
|
|
return Builder.load_string(
|
||
|
|
'''
|
||
|
|
MDScreen:
|
||
|
|
|
||
|
|
MDBottomNavigation:
|
||
|
|
panel_color: "#eeeaea"
|
||
|
|
selected_color_background: "#97ecf8"
|
||
|
|
text_color_active: "white"
|
||
|
|
|
||
|
|
MDBottomNavigationItem:
|
||
|
|
name: "screen 1"
|
||
|
|
text: "Mail"
|
||
|
|
icon: "gmail"
|
||
|
|
|
||
|
|
MDLabel:
|
||
|
|
text: "Mail"
|
||
|
|
halign: "center"
|
||
|
|
|
||
|
|
MDBottomNavigationItem:
|
||
|
|
name: "screen 2"
|
||
|
|
text: "Discord"
|
||
|
|
icon: "discord"
|
||
|
|
|
||
|
|
MDLabel:
|
||
|
|
text: "Discord"
|
||
|
|
halign: "center"
|
||
|
|
|
||
|
|
MDBottomNavigationItem:
|
||
|
|
name: "screen 3"
|
||
|
|
text: "LinkedIN"
|
||
|
|
icon: "linkedin"
|
||
|
|
|
||
|
|
MDLabel:
|
||
|
|
text: "LinkedIN"
|
||
|
|
halign: "center"
|
||
|
|
'''
|
||
|
|
)
|
||
|
|
|
||
|
|
|
||
|
|
Test().run()
|
||
|
|
|
||
|
|
.. image:: https://github.com/HeaTTheatR/KivyMD-data/raw/master/gallery/kivymddoc/bottom-navigation-styles-programming.png
|
||
|
|
:align: center
|
||
|
|
|
||
|
|
Looking at this code, we can now clearly see the widget tree and their properties.
|
||
|
|
We can quickly navigate through the components of the screen and quickly
|
||
|
|
change/add new properties/widgets. This is named declarative UI creation style.
|
||
|
|
|
||
|
|
But now the KivyMD library allows you to write Python code in a declarative style.
|
||
|
|
Just as it is implemented in Flutter/Jetpack Compose/SwiftUI.
|
||
|
|
|
||
|
|
Declarative style with Python code
|
||
|
|
----------------------------------
|
||
|
|
|
||
|
|
.. code-block:: python
|
||
|
|
|
||
|
|
from kivymd.app import MDApp
|
||
|
|
from kivymd.uix.bottomnavigation import MDBottomNavigation, MDBottomNavigationItem
|
||
|
|
from kivymd.uix.label import MDLabel
|
||
|
|
from kivymd.uix.screen import MDScreen
|
||
|
|
|
||
|
|
|
||
|
|
class Example(MDApp):
|
||
|
|
def build(self):
|
||
|
|
return (
|
||
|
|
MDScreen(
|
||
|
|
MDBottomNavigation(
|
||
|
|
MDBottomNavigationItem(
|
||
|
|
MDLabel(
|
||
|
|
text="Mail",
|
||
|
|
halign="center",
|
||
|
|
),
|
||
|
|
name="screen 1",
|
||
|
|
text="Mail",
|
||
|
|
icon="gmail",
|
||
|
|
),
|
||
|
|
MDBottomNavigationItem(
|
||
|
|
MDLabel(
|
||
|
|
text="Discord",
|
||
|
|
halign="center",
|
||
|
|
),
|
||
|
|
name="screen 2",
|
||
|
|
text="Discord",
|
||
|
|
icon="discord",
|
||
|
|
),
|
||
|
|
MDBottomNavigationItem(
|
||
|
|
MDLabel(
|
||
|
|
text="LinkedIN",
|
||
|
|
halign="center",
|
||
|
|
),
|
||
|
|
name="screen 3",
|
||
|
|
text="LinkedIN",
|
||
|
|
icon="linkedin",
|
||
|
|
),
|
||
|
|
panel_color="#eeeaea",
|
||
|
|
selected_color_background="#97ecf8",
|
||
|
|
text_color_active="white",
|
||
|
|
)
|
||
|
|
)
|
||
|
|
)
|
||
|
|
|
||
|
|
|
||
|
|
Example().run()
|
||
|
|
|
||
|
|
.. note:: The KivyMD library does not support creating Kivy widgets in Python
|
||
|
|
code in a declarative style.
|
||
|
|
|
||
|
|
But you can still use the declarative style of creating Kivy widgets in Python code.
|
||
|
|
To do this, you need to create a new class that will be inherited from the Kivy
|
||
|
|
widget and the :class:`~DeclarativeBehavior` class:
|
||
|
|
|
||
|
|
.. code-block:: python
|
||
|
|
|
||
|
|
from kivy.uix.boxlayout import BoxLayout
|
||
|
|
from kivy.uix.button import Button
|
||
|
|
|
||
|
|
from kivymd.app import MDApp
|
||
|
|
from kivymd.uix.behaviors import DeclarativeBehavior
|
||
|
|
|
||
|
|
|
||
|
|
class DeclarativeStyleBoxLayout(DeclarativeBehavior, BoxLayout):
|
||
|
|
pass
|
||
|
|
|
||
|
|
|
||
|
|
class Example(MDApp):
|
||
|
|
def build(self):
|
||
|
|
return (
|
||
|
|
DeclarativeStyleBoxLayout(
|
||
|
|
Button(),
|
||
|
|
Button(),
|
||
|
|
orientation="vertical",
|
||
|
|
)
|
||
|
|
)
|
||
|
|
|
||
|
|
|
||
|
|
Example().run()
|
||
|
|
|
||
|
|
Get objects by identifiers
|
||
|
|
--------------------------
|
||
|
|
|
||
|
|
In the declarative style in Python code, the ids parameter of the specified
|
||
|
|
widget will return only the id of the child widget/container, ignoring other ids.
|
||
|
|
Therefore, to get objects by identifiers in declarative style in Python code,
|
||
|
|
you must specify all the container ids in which the widget is nested until you
|
||
|
|
get to the desired id:
|
||
|
|
|
||
|
|
.. code-block::
|
||
|
|
|
||
|
|
from kivymd.app import MDApp
|
||
|
|
from kivymd.uix.boxlayout import MDBoxLayout
|
||
|
|
from kivymd.uix.button import MDRaisedButton
|
||
|
|
from kivymd.uix.floatlayout import MDFloatLayout
|
||
|
|
|
||
|
|
|
||
|
|
class Example(MDApp):
|
||
|
|
def build(self):
|
||
|
|
return (
|
||
|
|
MDBoxLayout(
|
||
|
|
MDFloatLayout(
|
||
|
|
MDRaisedButton(
|
||
|
|
id="button_1",
|
||
|
|
text="Button 1",
|
||
|
|
pos_hint={"center_x": 0.5, "center_y": 0.5},
|
||
|
|
),
|
||
|
|
id="box_container_1",
|
||
|
|
),
|
||
|
|
MDBoxLayout(
|
||
|
|
MDFloatLayout(
|
||
|
|
MDRaisedButton(
|
||
|
|
id="button_2",
|
||
|
|
text="Button 2",
|
||
|
|
pos_hint={"center_x": 0.5, "center_y": 0.5},
|
||
|
|
),
|
||
|
|
id="float_container",
|
||
|
|
),
|
||
|
|
id="box_container_2",
|
||
|
|
)
|
||
|
|
)
|
||
|
|
)
|
||
|
|
|
||
|
|
def on_start(self):
|
||
|
|
# {
|
||
|
|
# 'box_container_1': <kivymd.uix.floatlayout.MDFloatLayout>,
|
||
|
|
# 'box_container_2': <kivymd.uix.boxlayout.MDBoxLayout object>
|
||
|
|
# }
|
||
|
|
print(self.root.ids)
|
||
|
|
|
||
|
|
# <kivymd.uix.button.button.MDRaisedButton>
|
||
|
|
print(self.root.ids.box_container_2.ids.float_container.ids.button_2)
|
||
|
|
|
||
|
|
|
||
|
|
Example().run()
|
||
|
|
|
||
|
|
Yes, this is not a very good solution, but I think it will be fixed soon.
|
||
|
|
|
||
|
|
.. warning:: Declarative programming style in Python code in the KivyMD library
|
||
|
|
is an experimental feature. Therefore, if you receive errors, do not hesitate
|
||
|
|
to create new issue in the KivyMD repository.
|
||
|
|
"""
|
||
|
|
|
||
|
|
from kivy.properties import StringProperty
|
||
|
|
from kivy.uix.widget import Widget
|
||
|
|
|
||
|
|
|
||
|
|
class DeclarativeBehavior:
|
||
|
|
"""
|
||
|
|
Implements the creation and addition of child widgets as declarative
|
||
|
|
programming style.
|
||
|
|
"""
|
||
|
|
|
||
|
|
id = StringProperty()
|
||
|
|
"""
|
||
|
|
Widget ID.
|
||
|
|
|
||
|
|
:attr:`id` is an :class:`~kivy.properties.StringProperty`
|
||
|
|
and defaults to `''`.
|
||
|
|
"""
|
||
|
|
|
||
|
|
def __init__(self, *args, **kwargs):
|
||
|
|
super().__init__(**kwargs)
|
||
|
|
|
||
|
|
for child in args:
|
||
|
|
if issubclass(child.__class__, Widget):
|
||
|
|
self.add_widget(child)
|
||
|
|
if hasattr(child, "id") and child.id:
|
||
|
|
self.ids[child.id] = child
|