如何在 python-prompt-toolkit 中将 pageup/pagedown 键绑定添加到 TextArea?

How do you add pageup/pagedown keybindings to TextArea in python-prompt-toolkit?

我们以calculator.py为例。

要添加与鼠标滚轮一起使用的滚动条,您需要更改:

output_field = TextArea(style="class:output-field", text=help_text)

至:

output_field = TextArea(style="class:output-field", text=help_text, scrollbar=True)

但是您会添加或更改什么来使用向上翻页和向下翻页键滚动 TextArea?

# The key bindings.
kb = KeyBindings()

@kb.add("pageup")
def _(event):
    # What goes here?
    pass

@kb.add("pagedown")
def _(event):
    # What goes here?
    pass

改变焦点

最简单的方法可能是导入 focus_next(或 focus_previous

from prompt_toolkit.key_binding.bindings.focus import focus_next

并将其绑定到 Control-Space(或其他任何东西)。

# The key bindings.
kb = KeyBindings()

kb.add("c-space")(focus_next)

保持专注

您还可以,为了看似将注意力集中在 input_field 上,导入 scroll_page_upscroll_page_down

from prompt_toolkit.key_binding.bindings.page_navigation import scroll_page_up, scroll_page_down

然后将焦点切换到 output_field,调用 scroll_page_up/scroll_page_down,最后将焦点切换回 input_field

# The key bindings.
kb = KeyBindings()

@kb.add("pageup")
def _(event):
    w = event.app.layout.current_window
    event.app.layout.focus(output_field.window)
    scroll_page_up(event)
    event.app.layout.focus(w)

@kb.add("pagedown")
def _(event):
    w = event.app.layout.current_window
    event.app.layout.focus(output_field.window)
    scroll_page_down(event)
    event.app.layout.focus(w)