Textual Textarea

Note: This is NOT the official TextArea widget!

With v0.38.0, Textual added a built-in TextArea widget. You probably want to use that widget instead of this one. This project predated the official widget; versions < v0.8.0 had a completely separate implmentation.

Since v0.8.0, this project uses the built-in TextArea widget, but adds the features outlined below.

Installation

pip install textual-textarea

Features

Full-featured text editor experience with VS-Code-like bindings, in your Textual App:

Syntax highlighting and support for Pygments themes.
Move cursor and scroll with mouse or keys (including ctrl+arrow, PgUp/Dn, ctrl+Home/End).
Open (ctrl+o) and save (ctrl+s) files.
Cut (ctrl+x), copy (ctrl+c), paste (ctrl+u/v), optionally using the system clipboard.
Comment selections with ctrl+/.
Indent and dedent (optionally for a multiline selection) to tab stops with Tab and shift+Tab.
Automatic completions of quotes and brackets.
Select text by double-, triple-, or quadruple-clicking.
Quit with ctrl+q.

Usage

Initializing the Widget

The TextArea is a Textual Widget. You can add it to a Textual app using compose or mount:

from textual_textarea import TextEditor
from textual.app import App, ComposeResult

class TextApp(App, inherit_bindings=False):
    def compose(self) -> ComposeResult:
        yield TextEditor(text="hi", language="python", theme="nord-darker", id="ta")

    def on_mount(self) -> None:
        editor = self.query_one("#id", expect_type=TextEditor)
        editor.focus()

app = TextApp()
app.run()

In addition to the standard Widget arguments, TextArea accepts three additional, optional arguments when initializing the widget:

language (str): Must be None or the short name of a Pygments lexer, e.g., python, sql, as3. Defaults to None.
theme (str): Must be name of a Pygments style, e.g., bw, github-dark, solarized-light. Defaults to monokai.
use_system_clipboard (bool): Set to False to make the TextArea's copy and paste operations ignore the system clipboard. Defaults to True. Some Linux users may need to apt-install xclip or xsel to enable the system clipboard features.

The TextArea supports many actions and key bindings. For proper binding of ctrl+c to the COPY action, you must initialize your App with inherit_bindings=False (as shown above), so that ctrl+c does not quit the app. The TextArea implements ctrl+q as quit; you way wish to mimic that in your app so that other in-focus widgets use the same behavior.

Interacting with the Widget

Getting and Setting Text

The TextArea exposes a text property that contains the full text contained in the widget. You can retrieve or set the text by interacting with this property:

editor = self.query_one(TextEditor)
old_text = editor.text
editor.text = "New Text!\n\nMany Lines!"

Similarly, the TextEditor exposes a selected_text property (read-only):

editor = self.query_one(TextEditor)
selection = editor.selected_text

Inserting Text

You can insert text at the current selection:

editor = self.query_one(TextEditor)
editor.text = "01234"
editor.selection = Selection((0, 2), (0, 2))
editor.insert_text_at_selection("\nabc\n")
assert editor.text == "01\nabc\n234"
assert editor.selection == Selection((2, 0), (2, 0))

Getting and Setting The Cursor Position

The TextEditor exposes a selection property that returns a textual.widgets.text_area.Selection:

editor = self.query_one(TextEditor)
old_selection = editor.selection
editor.selection = Selection((999, 0),(999, 0))  # the cursor will move as close to line 999, pos 0 as possible
cursor_line_number = editor.selection.end[0]
cursor_x_position = editor.selection.end[1]

Getting and Setting The Language

Syntax highlighting and comment insertion depends on the configured language for the TextEditor.

The TextArea exposes a language property that returns None or a string that is equal to the short name of an installed tree-sitter language:

editor = self.query_one(TextEditor)
old_language = editor.language
editor.language = "python"

Getting Theme Colors

If you would like the rest of your app to match the colors from the TextArea's theme, they are exposed via the theme_colors property.

editor = self.query_one(TextEditor)
color = editor.theme_colors.contrast_text_color
bgcolor = editor.theme_colors.bgcolor
highlight = editor.theme_colors.selection_bgcolor

Adding Bindings and other Behavior

You can subclass TextEditor to add your own behavior. This snippet adds an action that posts a Submitted message containing the text of the TextEditor when the user presses ctrl+j:

from textual.message import Message
from textual_textarea import TextEditor


class CodeEditor(TextEditor):
    BINDINGS = [
        ("ctrl+j", "submit", "Run Query"),
    ]

    class Submitted(Message, bubble=True):
        def __init__(self, text: str) -> None:
            super().__init__()
            self.text = text

    async def action_submit(self) -> None:
        self.post_message(self.Submitted(self.text))

tconbeer/textual-textarea