python – 具有动态网格布局的Kivy模板

|----------|
|          | 
| IMAGE    |   <--- Just an image (square)
|          |
|----------| 
|[btn][btn]|   <--- GridLayout cols=2 of buttons 
|[btn][btn]| 
|[btn][btn]| 
|[btn][btn]| 
|[btn][btn]| 
|[btn][btn]|
|----------|

第一部分很简单(但我可能错了,因为我在kivy很新)

#:kivy 1.6
[SideBar@BoxLayout]:
    orientation: 'vertical'
    Image:
        source: ctx.image
        size_hint: (1, None)
        height: root.width
    GridLayout:
        cols: 2
        # What do I do here to make it easy to load a list of buttons?

#!/usr/bin/env python2
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.button import Button

Builder.load_string('''
#:kivy 1.6
[SideBar@BoxLayout]:
    content: content
    orientation: 'vertical'
    size_hint: ctx.size_hint if hasattr(ctx, 'size_hint') else (1, 1)
    Image:
        source: ctx.image
        size_hint: (1, None)
        height: root.width
    GridLayout:
        cols: 2
        # just add a id that can be accessed later on
        id: content

<Root>:
    Button:
        center_x: root.center_x
        text: 'press to add_widgets'
        size_hint: .2, .2
        on_press:
            # what comes after `:` is basically normal python code
            sb.content.clear_widgets()
            # however using a callback that you can control in python
            # gives you more control
            root.load_content(sb.content)
    SideBar:
        id: sb
        size_hint: .2, 1
        image: 'data/images/image-loading.gif'
''')

class Root(FloatLayout):

    def load_content(self, content):
        for but in range(20):
            content.add_widget(Button(
                                text=str(but)))

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

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

我希望内联注释能够使示例清晰.在这种情况下,我们只是将内容的引用传递给向内容添加小部件的函数.

在某些情况下,您可能希望将Widget作为自己类的属性进行访问.在这种情况下,您可以使用以下method.

上面的方法基本上添加了与id相同名称的ObjectProperty,将id引用的小部件的引用传递给它.因此,您现在拥有一个与您的python类中的id同名的属性,以便于访问.使用上面提到的方法,您的代码看起来像这样.

#!/usr/bin/env python2
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.button import Button
from kivy.properties import ObjectProperty

Builder.load_string('''
#:kivy 1.6
[SideBar@BoxLayout]:
    content: content
    orientation: 'vertical'
    size_hint: ctx.size_hint if hasattr(ctx, 'size_hint') else (1, 1)
    Image:
        source: ctx.image
        size_hint: (1, None)
        height: root.width
    GridLayout:
        cols: 2
        # just add a id that can be accessed later on
        id: content

<Root>:
    content: sb.content
    Button:
        center_x: root.center_x
        text: 'press to add_widgets'
        size_hint: .2, .2
        on_press:
            sb.content.clear_widgets()
            root.load_content()
    SideBar:
        id: sb
        size_hint: .2, 1
        image: 'data/images/image-loading.gif'
''')

class Root(FloatLayout):

    content = ObjectProperty(None)
    '''This is initialised to None and in kv code at line 28
    above (the one with `content: sb.content`) a ref to the
    actual content is passed'''

    def load_content(self):
        content = self.content
        for but in range(20):
            content.add_widget(Button(
                                text=str(but)))

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

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