TextArea¶
Tip
Added in version 0.38.0. Soft wrapping added in version 0.48.0.
A widget for editing text which may span multiple lines. Supports text selection, soft wrapping, optional syntax highlighting with tree-sitter and a variety of keybindings.
- Focusable
- Container
Guide¶
Code editing vs plain text editing¶
By default, the TextArea widget is a standard multi-line input box with soft-wrapping enabled.
If you're interested in editing code, you may wish to use the TextArea.code_editor convenience constructor.
This is a method which, by default, returns a new TextArea with soft-wrapping disabled, line numbers enabled, and the tab key behavior configured to insert \t.
Syntax highlighting dependencies¶
To enable syntax highlighting, you'll need to install the syntax extra dependencies:
This will install tree-sitter and tree-sitter-languages.
These packages are distributed as binary wheels, so it may limit your applications ability to run in environments where these wheels are not available.
After installing, you can set the language reactive attribute on the TextArea to enable highlighting.
Loading text¶
In this example we load some initial text into the TextArea, and set the language to "python" to enable syntax highlighting.
from textual.app import App, ComposeResult
from textual.widgets import TextArea
TEXT = """\
def hello(name):
print("hello" + name)
def goodbye(name):
print("goodbye" + name)
"""
class TextAreaExample(App):
def compose(self) -> ComposeResult:
yield TextArea.code_editor(TEXT, language="python")
app = TextAreaExample()
if __name__ == "__main__":
app.run()
To update the content programmatically, set the text property to a string value.
To update the parser used for syntax highlighting, set the language reactive attribute:
Note
More built-in languages will be added in the future. For now, you can add your own.
Reading content from TextArea¶
There are a number of ways to retrieve content from the TextArea:
- The
TextArea.textproperty returns all content in the text area as a string. - The
TextArea.selected_textproperty returns the text corresponding to the current selection. - The
TextArea.get_text_rangemethod returns the text between two locations.
In all cases, when multiple lines of text are retrieved, the document line separator will be used.
Editing content inside TextArea¶
The content of the TextArea can be updated using the replace method.
This method is the programmatic equivalent of selecting some text and then pasting.
Some other convenient methods are available, such as insert, delete, and clear.
Tip
The TextArea.document.end property returns the location at the end of the
document, which might be convenient when editing programmatically.
Working with the cursor¶
Moving the cursor¶
The cursor location is available via the cursor_location property, which represents
the location of the cursor as a tuple (row_index, column_index). These indices are zero-based and represent the position of the cursor in the content.
Writing a new value to cursor_location will immediately update the location of the cursor.
>>> text_area = TextArea()
>>> text_area.cursor_location
(0, 0)
>>> text_area.cursor_location = (0, 4)
>>> text_area.cursor_location
(0, 4)
cursor_location is a simple way to move the cursor programmatically, but it doesn't let us select text.
Selecting text¶
To select text, we can use the selection reactive attribute.
Let's select the first two lines of text in a document by adding text_area.selection = Selection(start=(0, 0), end=(2, 0)) to our code:
from textual.app import App, ComposeResult
from textual.widgets import TextArea
from textual.widgets.text_area import Selection
TEXT = """\
def hello(name):
print("hello" + name)
def goodbye(name):
print("goodbye" + name)
"""
class TextAreaSelection(App):
def compose(self) -> ComposeResult:
text_area = TextArea.code_editor(TEXT, language="python")
text_area.selection = Selection(start=(0, 0), end=(2, 0)) # (1)!
yield text_area
app = TextAreaSelection()
if __name__ == "__main__":
app.run()
- Selects the first two lines of text.
Note that selections can happen in both directions, so Selection((2, 0), (0, 0)) is also valid.
Tip
The end attribute of the selection is always equal to TextArea.cursor_location. In other words,
the cursor_location attribute is simply a convenience for accessing text_area.selection.end.
More cursor utilities¶
There are a number of additional utility methods available for interacting with the cursor.
Location information¶
Many properties exist on TextArea which give information about the current cursor location.
These properties begin with cursor_at_, and return booleans.
For example, cursor_at_start_of_line tells us if the cursor is at a start of line.
We can also check the location the cursor would arrive at if we were to move it.
For example, get_cursor_right_location returns the location
the cursor would move to if it were to move right.
A number of similar methods exist, with names like get_cursor_*_location.
Cursor movement methods¶
The move_cursor method allows you to move the cursor to a new location while selecting
text, or move the cursor and scroll to keep it centered.
# Move the cursor from its current location to row index 4,
# column index 8, while selecting all the text between.
text_area.move_cursor((4, 8), select=True)
The move_cursor_relative method offers a very similar interface, but moves the cursor relative
to its current location.
Common selections¶
There are some methods available which make common selections easier:
select_lineselects a line by index. Bound to F6 by default.select_allselects all text. Bound to F7 by default.
Themes¶
TextArea ships with some builtin themes, and you can easily add your own.
Themes give you control over the look and feel, including syntax highlighting, the cursor, selection, gutter, and more.
Default theme¶
The default TextArea theme is called css, which takes its values entirely from CSS.
This means that the default appearance of the widget fits nicely into a standard Textual application,
and looks right on both dark and light mode.
When using the css theme, you can make use of component classes to style elements of the TextArea.
For example, the CSS code TextArea .text-area--cursor { background: green; } will make the cursor green.
More complex applications such as code editors may want to use pre-defined themes such as monokai.
This involves using a TextAreaTheme object, which we cover in detail below.
This allows full customization of the TextArea, including syntax highlighting, at the code level.
Using builtin themes¶
The initial theme of the TextArea is determined by the theme parameter.
# Create a TextArea with the 'dracula' theme.
yield TextArea.code_editor("print(123)", language="python", theme="dracula")
You can check which themes are available using the available_themes property.
>>> text_area = TextArea()
>>> print(text_area.available_themes)
{'css', 'dracula', 'github_light', 'monokai', 'vscode_dark'}
After creating a TextArea, you can change the theme by setting the theme
attribute to one of the available themes.
On setting this attribute the TextArea will immediately refresh to display the updated theme.
Custom themes¶
Note
Custom themes are only relevant for people who are looking to customize syntax highlighting.
If you're only editing plain text, and wish to recolor aspects of the TextArea, you should use the provided component classes.
Using custom (non-builtin) themes is a two-step process:
- Create an instance of
TextAreaTheme. - Register it using
TextArea.register_theme.
1. Creating a theme¶
Let's create a simple theme, "my_cool_theme", which colors the cursor blue, and the cursor line yellow.
Our theme will also syntax highlight strings as red, and comments as magenta.
from rich.style import Style
from textual.widgets.text_area import TextAreaTheme
# ...
my_theme = TextAreaTheme(
# This name will be used to refer to the theme...
name="my_cool_theme",
# Basic styles such as background, cursor, selection, gutter, etc...
cursor_style=Style(color="white", bgcolor="blue"),
cursor_line_style=Style(bgcolor="yellow"),
# `syntax_styles` is for syntax highlighting.
# It maps tokens parsed from the document to Rich styles.
syntax_styles={
"string": Style(color="red"),
"comment": Style(color="magenta"),
}
)
Attributes like cursor_style and cursor_line_style apply general language-agnostic
styling to the widget.
If you choose not to supply a value for one of these attributes, it will be taken from the CSS component styles.
The syntax_styles attribute of TextAreaTheme is used for syntax highlighting and
depends on the language currently in use.
For more details, see syntax highlighting.
If you wish to build on an existing theme, you can obtain a reference to it using the TextAreaTheme.get_builtin_theme classmethod:
from textual.widgets.text_area import TextAreaTheme
monokai = TextAreaTheme.get_builtin_theme("monokai")
2. Registering a theme¶
Our theme can now be registered with the TextArea instance.
After registering a theme, it'll appear in the available_themes:
>>> print(text_area.available_themes)
{'dracula', 'github_light', 'monokai', 'vscode_dark', 'my_cool_theme'}
We can now switch to it:
This immediately updates the appearance of the TextArea:
Tab and Escape behavior¶
Pressing the Tab key will shift focus to the next widget in your application by default. This matches how other widgets work in Textual.
To have Tab insert a \t character, set the tab_behavior attribute to the string value "indent".
While in this mode, you can shift focus by pressing the Esc key.
Indentation¶
The character(s) inserted when you press tab is controlled by setting the indent_type attribute to either tabs or spaces.
If indent_type == "spaces", pressing Tab will insert up to indent_width spaces in order to align with the next tab stop.
Undo and redo¶
TextArea offers undo and redo methods.
By default, undo is bound to Ctrl+Z and redo to Ctrl+Y.
The TextArea uses a heuristic to place checkpoints after certain types of edit.
When you call undo, all of the edits between now and the most recent checkpoint are reverted.
You can manually add a checkpoint by calling the TextArea.history.checkpoint() instance method.
The undo and redo history uses a stack-based system, where a single item on the stack represents a single checkpoint.
In memory-constrained environments, you may wish to reduce the maximum number of checkpoints that can exist.
You can do this by passing the max_checkpoints argument to the TextArea constructor.
Read-only mode¶
TextArea.read_only is a boolean reactive attribute which, if True, will prevent users from modifying content in the TextArea.
While read_only=True, you can still modify the content programmatically.
While this mode is active, the TextArea receives the -read-only CSS class, which you can use to supply custom styles for read-only mode.
Line separators¶
When content is loaded into TextArea, the content is scanned from beginning to end
and the first occurrence of a line separator is recorded.
This separator will then be used when content is later read from the TextArea via
the text property. The TextArea widget does not support exporting text which
contains mixed line endings.
Similarly, newline characters pasted into the TextArea will be converted.
You can check the line separator of the current document by inspecting TextArea.document.newline:
Line numbers¶
The gutter (column on the left containing line numbers) can be toggled by setting
the show_line_numbers attribute to True or False.
Setting this attribute will immediately repaint the TextArea to reflect the new value.
You can also change the start line number (the topmost line number in the gutter) by setting the line_number_start reactive attribute.
Extending TextArea¶
Sometimes, you may wish to subclass TextArea to add some extra functionality.
In this section, we'll briefly explore how we can extend the widget to achieve common goals.
Hooking into key presses¶
You may wish to hook into certain key presses to inject some functionality.
This can be done by over-riding _on_key and adding the required functionality.
Example - closing parentheses automatically¶
Let's extend TextArea to add a feature which automatically closes parentheses and moves the cursor to a sensible location.
from textual import events
from textual.app import App, ComposeResult
from textual.widgets import TextArea
class ExtendedTextArea(TextArea):
"""A subclass of TextArea with parenthesis-closing functionality."""
def _on_key(self, event: events.Key) -> None:
if event.character == "(":
self.insert("()")
self.move_cursor_relative(columns=-1)
event.prevent_default()
class TextAreaKeyPressHook(App):
def compose(self) -> ComposeResult:
yield ExtendedTextArea.code_editor(language="python")
app = TextAreaKeyPressHook()
if __name__ == "__main__":
app.run()
This intercepts the key handler when "(" is pressed, and inserts "()" instead.
It then moves the cursor so that it lands between the open and closing parentheses.
Typing "def hello(" into the TextArea now results in the bracket automatically being closed:
Advanced concepts¶
Syntax highlighting¶
Syntax highlighting inside the TextArea is powered by a library called tree-sitter.
Each time you update the document in a TextArea, an internal syntax tree is updated.
This tree is frequently queried to find location ranges relevant to syntax highlighting.
We give these ranges names, and ultimately map them to Rich styles inside TextAreaTheme.syntax_styles.
To illustrate how this works, lets look at how the "Monokai" TextAreaTheme highlights Markdown files.
When the language attribute is set to "markdown", a highlight query similar to the one below is used (trimmed for brevity).
This highlight query maps heading_content nodes returned by the Markdown parser to the name @heading,
and link nodes to the name @link.
Inside our TextAreaTheme.syntax_styles dict, we can map the name @heading to a Rich style.
Here's a snippet from the "Monokai" theme which does just that:
TextAreaTheme(
name="monokai",
base_style=Style(color="#f8f8f2", bgcolor="#272822"),
gutter_style=Style(color="#90908a", bgcolor="#272822"),
# ...
syntax_styles={
# Colorise @heading and make them bold
"heading": Style(color="#F92672", bold=True),
# Colorise and underline @link
"link": Style(color="#66D9EF", underline=True),
# ...
},
)
To understand which names can be mapped inside syntax_styles, we recommend looking at the existing
themes and highlighting queries (.scm files) in the Textual repository.
Tip
You may also wish to take a look at the contents of TextArea._highlights on an
active TextArea instance to see which highlights have been generated for the
open document.
Adding support for custom languages¶
To add support for a language to a TextArea, use the register_language method.
To register a language, we require two things:
- A tree-sitter
Languageobject which contains the grammar for the language. - A highlight query which is used for syntax highlighting.
Example - adding Java support¶
The easiest way to obtain a Language object is using the py-tree-sitter-languages package. Here's how we can use this package to obtain a reference to a Language object representing Java:
The exact version of the parser used when you call get_language can be checked via
the repos.txt file in
the version of py-tree-sitter-languages you're using. This file contains links to the GitHub
repos and commit hashes of the tree-sitter parsers. In these repos you can often find pre-made highlight queries at queries/highlights.scm,
and a file showing all the available node types which can be used in highlight queries at src/node-types.json.
Since we're adding support for Java, lets grab the Java highlight query from the repo by following these steps:
- Open
repos.txtfile from thepy-tree-sitter-languagesrepo. - Find the link corresponding to
tree-sitter-javaand go to the repo on GitHub (you may also need to go to the specific commit referenced inrepos.txt). - Go to
queries/highlights.scmto see the example highlight query for Java.
Be sure to check the license in the repo to ensure it can be freely copied.
Warning
It's important to use a highlight query which is compatible with the parser in use, so
pay attention to the commit hash when visiting the repo via repos.txt.
We now have our Language and our highlight query, so we can register Java as a language.
from pathlib import Path
from tree_sitter_languages import get_language
from textual.app import App, ComposeResult
from textual.widgets import TextArea
java_language = get_language("java")
java_highlight_query = (Path(__file__).parent / "java_highlights.scm").read_text()
java_code = """\
class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello, World!");
}
}
"""
class TextAreaCustomLanguage(App):
def compose(self) -> ComposeResult:
text_area = TextArea.code_editor(text=java_code)
text_area.cursor_blink = False
# Register the Java language and highlight query
text_area.register_language("java", java_language, java_highlight_query)
# Switch to Java
text_area.language = "java"
yield text_area
app = TextAreaCustomLanguage()
if __name__ == "__main__":
app.run()
Running our app, we can see that the Java code is highlighted. We can freely edit the text, and the syntax highlighting will update immediately.
Recall that we map names (like @heading) from the tree-sitter highlight query to Rich style objects inside the TextAreaTheme.syntax_styles dictionary.
If you notice some highlights are missing after registering a language, the issue may be:
- The current
TextAreaThemedoesn't contain a mapping for the name in the highlight query. Adding a new key-value pair tosyntax_stylesshould resolve the issue. - The highlight query doesn't assign a name to the pattern you expect to be highlighted. In this case you'll need to update the highlight query to assign to the name.
Tip
The names assigned in tree-sitter highlight queries are often reused across multiple languages.
For example, @string is used in many languages to highlight strings.
Navigation and wrapping information¶
If you're building functionality on top of TextArea, it may be useful to inspect the navigator and wrapped_document attributes.
navigatoris aDocumentNavigatorinstance which can give us general information about the cursor's location within a document, as well as where the cursor will move to when certain actions are performed.wrapped_documentis aWrappedDocumentinstance which can be used to convert document locations to visual locations, taking wrapping into account. It also offers a variety of other convenience methods and properties.
A detailed view of these classes is out of scope, but do note that a lot of the functionality of TextArea exists within them, so inspecting them could be worthwhile.
Reactive attributes¶
| Name | Type | Default | Description |
|---|---|---|---|
language |
str | None |
None |
The language to use for syntax highlighting. |
theme |
str |
"css" |
The theme to use. |
selection |
Selection |
Selection() |
The current selection. |
show_line_numbers |
bool |
False |
Show or hide line numbers. |
line_number_start |
int |
1 |
The start line number in the gutter. |
indent_width |
int |
4 |
The number of spaces to indent and width of tabs. |
match_cursor_bracket |
bool |
True |
Enable/disable highlighting matching brackets under cursor. |
cursor_blink |
bool |
True |
Enable/disable blinking of the cursor when the widget has focus. |
soft_wrap |
bool |
True |
Enable/disable soft wrapping. |
read_only |
bool |
False |
Enable/disable read-only mode. |
Messages¶
Bindings¶
The TextArea widget defines the following bindings:
| Key(s) | Description |
|---|---|
| up | Move the cursor up. |
| down | Move the cursor down. |
| left | Move the cursor left. |
| ctrl+left | Move the cursor to the start of the word. |
| ctrl+shift+left | Move the cursor to the start of the word and select. |
| right | Move the cursor right. |
| ctrl+right | Move the cursor to the end of the word. |
| ctrl+shift+right | Move the cursor to the end of the word and select. |
| home,ctrl+a | Move the cursor to the start of the line. |
| end,ctrl+e | Move the cursor to the end of the line. |
| shift+home | Move the cursor to the start of the line and select. |
| shift+end | Move the cursor to the end of the line and select. |
| pageup | Move the cursor one page up. |
| pagedown | Move the cursor one page down. |
| shift+up | Select while moving the cursor up. |
| shift+down | Select while moving the cursor down. |
| shift+left | Select while moving the cursor left. |
| shift+right | Select while moving the cursor right. |
| backspace | Delete character to the left of cursor. |
| ctrl+w | Delete from cursor to start of the word. |
| delete,ctrl+d | Delete character to the right of cursor. |
| ctrl+f | Delete from cursor to end of the word. |
| ctrl+shift+k | Delete the current line. |
| ctrl+u | Delete from cursor to the start of the line. |
| ctrl+k | Delete from cursor to the end of the line. |
| f6 | Select the current line. |
| f7 | Select all text in the document. |
| ctrl+z | Undo. |
| ctrl+y | Redo. |
| ctrl+x | Cut selection or line if no selection. |
| ctrl+c | Copy selection to clipboard. |
| ctrl+v | Paste from clipboard. |
Component classes¶
The TextArea defines component classes that can style various aspects of the widget.
Styles from the theme attribute take priority.
TextArea offers some component classes which can be used to style aspects of the widget.
Note that any attributes provided in the chosen TextAreaTheme will take priority here.
| Class | Description |
|---|---|
text-area--cursor |
Target the cursor. |
text-area--gutter |
Target the gutter (line number column). |
text-area--cursor-gutter |
Target the gutter area of the line the cursor is on. |
text-area--cursor-line |
Target the line the cursor is on. |
text-area--selection |
Target the current selection. |
text-area--matching-bracket |
Target matching brackets. |
See also¶
Input- single-line text input widgetTextAreaTheme- theming theTextAreaDocumentNavigator- guides cursor movementWrappedDocument- manages wrapping the documentEditHistory- manages the undo stack- The tree-sitter documentation website.
- The tree-sitter Python bindings repository.
py-tree-sitter-languagesrepository (provides binary wheels for a large variety of tree-sitter languages).
Additional notes¶
- To remove the outline effect when the
TextAreais focused, you can setborder: none; padding: 0;in your CSS.
Bases: ScrollView
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
str
|
The initial text to load into the TextArea. |
''
|
|
str | None
|
The language to use. |
None
|
|
str
|
The theme to use. |
'css'
|
|
bool
|
Enable soft wrapping. |
True
|
|
Literal['focus', 'indent']
|
If 'focus', pressing tab will switch focus. If 'indent', pressing tab will insert a tab. |
'focus'
|
|
bool
|
Enable read-only mode. This prevents edits using the keyboard. |
False
|
|
bool
|
Show line numbers on the left edge. |
False
|
|
int
|
What line number to start on. |
1
|
|
int
|
The maximum number of undo history checkpoints to retain. |
50
|
|
str | None
|
The name of the |
None
|
|
str | None
|
The ID of the widget, used to refer to it from Textual CSS. |
None
|
|
str | None
|
One or more Textual CSS compatible class names separated by spaces. |
None
|
|
bool
|
True if the widget is disabled. |
False
|
|
RenderableType | None
|
Optional tooltip. |
None
|
|
bool
|
Enable compact style (without borders). |
False
|
class-attribute
instance-attribute
¶
BINDINGS = [
Binding("up", "cursor_up", "Cursor up", show=False),
Binding(
"down", "cursor_down", "Cursor down", show=False
),
Binding(
"left", "cursor_left", "Cursor left", show=False
),
Binding(
"right", "cursor_right", "Cursor right", show=False
),
Binding(
"ctrl+left",
"cursor_word_left",
"Cursor word left",
show=False,
),
Binding(
"ctrl+right",
"cursor_word_right",
"Cursor word right",
show=False,
),
Binding(
"home,ctrl+a",
"cursor_line_start",
"Cursor line start",
show=False,
),
Binding(
"end,ctrl+e",
"cursor_line_end",
"Cursor line end",
show=False,
),
Binding(
"pageup",
"cursor_page_up",
"Cursor page up",
show=False,
),
Binding(
"pagedown",
"cursor_page_down",
"Cursor page down",
show=False,
),
Binding(
"ctrl+shift+left",
"cursor_word_left(True)",
"Cursor left word select",
show=False,
),
Binding(
"ctrl+shift+right",
"cursor_word_right(True)",
"Cursor right word select",
show=False,
),
Binding(
"shift+home",
"cursor_line_start(True)",
"Cursor line start select",
show=False,
),
Binding(
"shift+end",
"cursor_line_end(True)",
"Cursor line end select",
show=False,
),
Binding(
"shift+up",
"cursor_up(True)",
"Cursor up select",
show=False,
),
Binding(
"shift+down",
"cursor_down(True)",
"Cursor down select",
show=False,
),
Binding(
"shift+left",
"cursor_left(True)",
"Cursor left select",
show=False,
),
Binding(
"shift+right",
"cursor_right(True)",
"Cursor right select",
show=False,
),
Binding("f6", "select_line", "Select line", show=False),
Binding("f7", "select_all", "Select all", show=False),
Binding(
"backspace",
"delete_left",
"Delete character left",
show=False,
),
Binding(
"ctrl+w",
"delete_word_left",
"Delete left to start of word",
show=False,
),
Binding(
"delete,ctrl+d",
"delete_right",
"Delete character right",
show=False,
),
Binding(
"ctrl+f",
"delete_word_right",
"Delete right to start of word",
show=False,
),
Binding("ctrl+x", "cut", "Cut", show=False),
Binding("ctrl+c", "copy", "Copy", show=False),
Binding("ctrl+v", "paste", "Paste", show=False),
Binding(
"ctrl+u",
"delete_to_start_of_line",
"Delete to line start",
show=False,
),
Binding(
"ctrl+k",
"delete_to_end_of_line_or_delete_line",
"Delete to line end",
show=False,
),
Binding(
"ctrl+shift+k",
"delete_line",
"Delete line",
show=False,
),
Binding("ctrl+z", "undo", "Undo", show=False),
Binding("ctrl+y", "redo", "Redo", show=False),
]
| Key(s) | Description |
|---|---|
| up | Move the cursor up. |
| down | Move the cursor down. |
| left | Move the cursor left. |
| ctrl+left | Move the cursor to the start of the word. |
| ctrl+shift+left | Move the cursor to the start of the word and select. |
| right | Move the cursor right. |
| ctrl+right | Move the cursor to the end of the word. |
| ctrl+shift+right | Move the cursor to the end of the word and select. |
| home,ctrl+a | Move the cursor to the start of the line. |
| end,ctrl+e | Move the cursor to the end of the line. |
| shift+home | Move the cursor to the start of the line and select. |
| shift+end | Move the cursor to the end of the line and select. |
| pageup | Move the cursor one page up. |
| pagedown | Move the cursor one page down. |
| shift+up | Select while moving the cursor up. |
| shift+down | Select while moving the cursor down. |
| shift+left | Select while moving the cursor left. |
| shift+right | Select while moving the cursor right. |
| backspace | Delete character to the left of cursor. |
| ctrl+w | Delete from cursor to start of the word. |
| delete,ctrl+d | Delete character to the right of cursor. |
| ctrl+f | Delete from cursor to end of the word. |
| ctrl+shift+k | Delete the current line. |
| ctrl+u | Delete from cursor to the start of the line. |
| ctrl+k | Delete from cursor to the end of the line. |
| f6 | Select the current line. |
| f7 | Select all text in the document. |
| ctrl+z | Undo. |
| ctrl+y | Redo. |
| ctrl+x | Cut selection or line if no selection. |
| ctrl+c | Copy selection to clipboard. |
| ctrl+v | Paste from clipboard. |
class-attribute
¶
COMPONENT_CLASSES = {
"text-area--cursor",
"text-area--gutter",
"text-area--cursor-gutter",
"text-area--cursor-line",
"text-area--selection",
"text-area--matching-bracket",
}
TextArea offers some component classes which can be used to style aspects of the widget.
Note that any attributes provided in the chosen TextAreaTheme will take priority here.
| Class | Description |
|---|---|
text-area--cursor |
Target the cursor. |
text-area--gutter |
Target the gutter (line number column). |
text-area--cursor-gutter |
Target the gutter area of the line the cursor is on. |
text-area--cursor-line |
Target the line the cursor is on. |
text-area--selection |
Target the current selection. |
text-area--matching-bracket |
Target matching brackets. |
property
¶
A set of the names of languages available to the TextArea.
The values in this set can be assigned to the language reactive attribute
of TextArea.
The returned set contains the builtin languages installed with the syntax extras,
plus those registered via the register_language method.
property
¶
A list of the names of the themes available to the TextArea.
The values in this list can be assigned theme reactive attribute of
TextArea.
You can retrieve the full specification for a theme by passing one of
the strings from this list into TextAreaTheme.get_by_name(theme_name: str).
Alternatively, you can directly retrieve a list of TextAreaTheme objects
(which contain the full theme specification) by calling
TextAreaTheme.builtin_themes().
property
¶
True if and only if the cursor is at the end of a row.
property
¶
True if and only if the cursor is at the very end of the document.
property
¶
True if and only if the cursor is on the first line.
property
¶
True if and only if the cursor is on the last line.
property
¶
True if and only if the cursor is at column 0.
property
¶
True if and only if the cursor is at location (0, 0)
class-attribute
instance-attribute
¶
True if the cursor should blink.
property
writable
¶
The current location of the cursor in the document.
This is a utility for accessing the end of TextArea.selection.
property
¶
The offset of the cursor relative to the screen.
instance-attribute
¶
The document this widget is currently editing.
property
¶
The width of the gutter (the left column containing line numbers).
Returns:
| Type | Description |
|---|---|
int
|
The cell-width of the line number column. If |
instance-attribute
¶
history = EditHistory(
max_checkpoints=max_checkpoints,
checkpoint_timer=2.0,
checkpoint_max_characters=100,
)
A stack (the end of the list is the top of the stack) for tracking edits.
class-attribute
instance-attribute
¶
The width of tabs or the multiple of spaces to align to on pressing the tab key.
If the document currently open contains tabs that are currently visible on screen, altering this value will immediately change the display width of the visible tabs.
property
¶
True if the TextArea is currently syntax aware - i.e. it's parsing document content.
class-attribute
instance-attribute
¶
language = language
The language to use.
This must be set to a valid, non-None value for syntax highlighting to work.
If the value is a string, a built-in language parser will be used if available.
If you wish to use an unsupported language, you'll have to register
it first using TextArea.register_language.
class-attribute
instance-attribute
¶
The line number the first line should be.
class-attribute
instance-attribute
¶
If the cursor is at a bracket, highlight the matching bracket (if found).
property
¶
The location of the matching bracket, if there is one.
instance-attribute
¶
navigator = DocumentNavigator(wrapped_document)
Queried to determine where the cursor should move given a navigation action, accounting for wrapping etc.
class-attribute
instance-attribute
¶
read_only = reactive(False)
True if the content is read-only.
Read-only means end users cannot insert, delete or replace content.
The document can still be edited programmatically via the API.
property
¶
The text between the start and end points of the current selection.
class-attribute
instance-attribute
¶
selection = reactive(
Selection(), init=False, always_update=True
)
The selection start and end locations (zero-based line_index, offset).
This represents the cursor location and the current selection.
The Selection.end always refers to the cursor location.
If no text is selected, then Selection.end == Selection.start is True.
The text selected in the document is available via the TextArea.selected_text property.
class-attribute
instance-attribute
¶
True to show the line number column on the left edge, otherwise False.
Changing this value will immediately re-render the TextArea.
class-attribute
instance-attribute
¶
True if text should soft wrap.
class-attribute
instance-attribute
¶
theme = theme
The name of the theme to use.
Themes must be registered using TextArea.register_theme before they can be used.
Syntax highlighting is only possible when the language attribute is set.
property
¶
The width which gets used when the document wraps.
Accounts for gutter, scrollbars, etc.
instance-attribute
¶
wrapped_document = WrappedDocument(document)
The wrapped view of the document.
dataclass
¶
Bases: Message
Posted when the content inside the TextArea changes.
Handle this message using the on decorator - @on(TextArea.Changed)
or a method named on_text_area_changed.
dataclass
¶
action_cursor_left(select=False)
Move the cursor one location to the left.
If the cursor is at the left edge of the document, try to move it to the end of the previous line.
If text is selected, move the cursor to the start of the selection.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
bool
|
If True, select the text while moving. |
False
|
Move the cursor to the end of the line.
Move the cursor to the start of the line.
Move the cursor right by a single word, skipping leading whitespace.
Deletes the character to the left of the cursor and updates the cursor location.
If there's a selection, then the selected range is deleted.
Deletes the character to the right of the cursor and keeps the cursor at the same location.
If there's a selection, then the selected range is deleted.
Deletes from the cursor location to the end of the line.
async
¶
Deletes from the cursor location to the end of the line, or deletes the line.
The line will be deleted if the line is empty.
Deletes from the cursor location to the start of the line.
Deletes the word to the left of the cursor and updates the cursor location.
Deletes the word to the right of the cursor and keeps the cursor at the same location.
Note that the location that we delete to using this action is not the same as the location we move to when we move the cursor one word to the right. This action does not skip leading whitespace, whereas cursor movement does.
Undo the edits since the last checkpoint (the most recent batch of edits).
cell_width_to_column_index(cell_width, row_index)
Return the column that the cell width corresponds to on the given row.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
int
|
The cell width to convert. |
required |
|
int
|
The index of the row to examine. |
required |
Returns:
| Type | Description |
|---|---|
int
|
The column corresponding to the cell width on that row. |
Check if the widget may consume the given key.
As a textarea we are expecting to capture printable keys.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
str
|
A key identifier. |
required |
|
str | None
|
A character associated with the key, or |
None
|
Returns:
| Type | Description |
|---|---|
bool
|
|
Delete all text from the document.
Returns:
| Type | Description |
|---|---|
EditResult
|
An EditResult relating to the deletion of all content. |
classmethod
¶
code_editor(
text="",
*,
language=None,
theme="monokai",
soft_wrap=False,
tab_behavior="indent",
read_only=False,
show_line_numbers=True,
line_number_start=1,
max_checkpoints=50,
name=None,
id=None,
classes=None,
disabled=False,
tooltip=None,
compact=False
)
Construct a new TextArea with sensible defaults for editing code.
This instantiates a TextArea with line numbers enabled, soft wrapping
disabled, "indent" tab behavior, and the "monokai" theme.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
str
|
The initial text to load into the TextArea. |
''
|
|
str | None
|
The language to use. |
None
|
|
str
|
The theme to use. |
'monokai'
|
|
bool
|
Enable soft wrapping. |
False
|
|
Literal['focus', 'indent']
|
If 'focus', pressing tab will switch focus. If 'indent', pressing tab will insert a tab. |
'indent'
|
|
bool
|
Show line numbers on the left edge. |
True
|
|
int
|
What line number to start on. |
1
|
|
str | None
|
The name of the |
None
|
|
str | None
|
The ID of the widget, used to refer to it from Textual CSS. |
None
|
|
str | None
|
One or more Textual CSS compatible class names separated by spaces. |
None
|
|
bool
|
True if the widget is disabled. |
False
|
|
RenderableType | None
|
Optional tooltip |
None
|
|
bool
|
Enable compact style (without borders). |
False
|
delete(start, end, *, maintain_selection_offset=True)
Delete the text between two locations in the document.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Location
|
The start location. |
required |
|
Location
|
The end location. |
required |
|
bool
|
If True, the active Selection will be updated such that the same text is selected before and after the selection, if possible. Otherwise, the cursor will jump to the end point of the edit. |
True
|
Returns:
| Type | Description |
|---|---|
EditResult
|
An |
edit(edit)
Perform an Edit.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Edit
|
The Edit to perform. |
required |
Returns:
| Type | Description |
|---|---|
EditResult
|
Data relating to the edit that may be useful. The data returned |
EditResult
|
may be different depending on the edit performed. |
find_matching_bracket(bracket, search_from)
If the character is a bracket, find the matching bracket.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
str
|
The character we're searching for the matching bracket of. |
required |
|
Location
|
The location to start the search. |
required |
Returns:
| Type | Description |
|---|---|
Location | None
|
The |
Location | None
|
If the character is not available for bracket matching, |
Get the cell offset of the column from the start of the row.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
int
|
The row index. |
required |
|
int
|
The column index (codepoint offset from start of row). |
required |
Returns:
| Type | Description |
|---|---|
int
|
The cell width of the column relative to the start of the row. |
Get the location the cursor will move to if it moves down.
Returns:
| Type | Description |
|---|---|
Location
|
The location the cursor will move to if it moves down. |
Get the location the cursor will move to if it moves left.
Returns:
| Type | Description |
|---|---|
Location
|
The location of the cursor if it moves left. |
Get the location of the end of the current line.
Returns:
| Type | Description |
|---|---|
Location
|
The (row, column) location of the end of the cursors current line. |
get_cursor_line_start_location(smart_home=False)
Get the location of the start of the current line.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
bool
|
If True, use "smart home key" behavior - go to the first non-whitespace character on the line, and if already there, go to offset 0. Smart home only works when wrapping is disabled. |
False
|
Returns:
| Type | Description |
|---|---|
Location
|
The (row, column) location of the start of the cursors current line. |
Get the location the cursor will move to if it moves right.
Returns:
| Type | Description |
|---|---|
Location
|
the location the cursor will move to if it moves right. |
Get the location the cursor will move to if it moves up.
Returns:
| Type | Description |
|---|---|
Location
|
The location the cursor will move to if it moves up. |
Get the location the cursor will jump to if it goes 1 word left.
Returns:
| Type | Description |
|---|---|
Location
|
The location the cursor will jump on "jump word left". |
Get the location the cursor will jump to if it goes 1 word right.
Returns:
| Type | Description |
|---|---|
Location
|
The location the cursor will jump on "jump word right". |
get_line(line_index)
Retrieve the line at the given line index.
You can stylize the Text object returned here to apply additional styling to TextArea content.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
int
|
The index of the line. |
required |
Returns:
| Type | Description |
|---|---|
Text
|
A |
get_target_document_location(event)
Given a MouseEvent, return the row and column offset of the event in document-space.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
MouseEvent
|
The MouseEvent. |
required |
Returns:
| Type | Description |
|---|---|
Location
|
The location of the mouse event within the document. |
insert(
text, location=None, *, maintain_selection_offset=True
)
Insert text into the document.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
str
|
The text to insert. |
required |
|
Location | None
|
The location to insert text, or None to use the cursor location. |
None
|
|
bool
|
If True, the active Selection will be updated such that the same text is selected before and after the selection, if possible. Otherwise, the cursor will jump to the end point of the edit. |
True
|
Returns:
| Type | Description |
|---|---|
EditResult
|
An |
move_cursor(
location, select=False, center=False, record_width=True
)
Move the cursor to a location.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Location
|
The location to move the cursor to. |
required |
|
bool
|
If True, select text between the old and new location. |
False
|
|
bool
|
If True, scroll such that the cursor is centered. |
False
|
|
bool
|
If True, record the cursor column cell width after navigating so that we jump back to the same width the next time we move to a row that is wide enough. |
True
|
move_cursor_relative(
rows=0,
columns=0,
select=False,
center=False,
record_width=True,
)
Move the cursor relative to its current location in document-space.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
int
|
The number of rows to move down by (negative to move up) |
0
|
|
int
|
The number of columns to move right by (negative to move left) |
0
|
|
bool
|
If True, select text between the old and new location. |
False
|
|
bool
|
If True, scroll such that the cursor is centered. |
False
|
|
bool
|
If True, record the cursor column cell width after navigating so that we jump back to the same width the next time we move to a row that is wide enough. |
True
|
Record the current cell width of the cursor.
This is used where we navigate up and down through rows. If we're in the middle of a row, and go down to a row with no content, then we go down to another row, we want our cursor to jump back to the same offset that we were originally at.
register_language(name, language, highlight_query)
Register a language and corresponding highlight query.
Calling this method does not change the language of the TextArea.
On switching to this language (via the language reactive attribute),
syntax highlighting will be performed using the given highlight query.
If a string name is supplied for a builtin supported language, then
this method will update the default highlight query for that language.
Registering a language only registers it to this instance of TextArea.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
str
|
The name of the language. |
required |
|
'Language'
|
A tree-sitter |
required |
|
str
|
The highlight query to use for syntax highlighting this language. |
required |
Register a theme for use by the TextArea.
After registering a theme, you can set themes by assigning the theme
name to the TextArea.theme reactive attribute. For example
text_area.theme = "my_custom_theme" where "my_custom_theme" is the
name of the theme you registered.
If you supply a theme with a name that already exists that theme will be overwritten.
replace(
insert, start, end, *, maintain_selection_offset=True
)
Replace text in the document with new text.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
str
|
The text to insert. |
required |
|
Location
|
The start location |
required |
|
Location
|
The end location. |
required |
|
bool
|
If True, the active Selection will be updated such that the same text is selected before and after the selection, if possible. Otherwise, the cursor will jump to the end point of the edit. |
True
|
Returns:
| Type | Description |
|---|---|
EditResult
|
An |
Scroll the TextArea such that the cursor is visible on screen.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
bool
|
True if the cursor should be scrolled to the center. |
False
|
|
bool
|
True if we should animate while scrolling. |
False
|
Returns:
| Type | Description |
|---|---|
Offset
|
The offset that was scrolled to bring the cursor into view. |
update_highlight_query(name, highlight_query)
module-attribute
¶
BUILTIN_LANGUAGES = [
"python",
"markdown",
"json",
"toml",
"yaml",
"html",
"css",
"javascript",
"rust",
"go",
"regex",
"sql",
"java",
"bash",
"xml",
]
Languages that are included in the syntax extras.
module-attribute
¶
Highlight = Tuple[StartColumn, EndColumn, HighlightName]
A tuple representing a syntax highlight within one line.
module-attribute
¶
A location (row, column) within the document. Indexing starts at 0.
Bases: DocumentBase
A document which can be opened in a TextArea.
property
¶
Get the document as a list of strings, where each string represents a line.
Newline characters are not included in at the end of the strings.
The newline character used in this document can be found via the Document.newline property.
get_location_from_index(index)
Given a codepoint index in the document's text, returns the corresponding location.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
int
|
The index in the document's text. |
required |
Returns:
| Type | Description |
|---|---|
Location
|
The corresponding location. |
Raises:
| Type | Description |
|---|---|
ValueError
|
If the index is doesn't correspond to a location in the document. |
Get the text that falls between the start and end locations.
Returns the text between start and end, including the appropriate
line separator character as specified by Document._newline. Note that
_newline is set automatically to the first line separator character
found in the document.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Location
|
The start location of the selection. |
required |
|
Location
|
The end location of the selection. |
required |
Returns:
| Type | Description |
|---|---|
str
|
The text between start (inclusive) and end (exclusive). |
Replace text at the given range.
This is the only method by which a document may be updated.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Location
|
A tuple (row, column) where the edit starts. |
required |
|
Location
|
A tuple (row, column) where the edit ends. |
required |
|
str
|
The text to insert between start and end. |
required |
Returns:
| Type | Description |
|---|---|
EditResult
|
The EditResult containing information about the completed replace operation. |
Bases: ABC
Describes the minimum functionality a Document implementation must provide in order to be used by the TextArea widget.
abstractmethod
property
¶
Get the lines of the document as a list of strings.
The strings should not include newline characters. The newline character used for the document can be retrieved via the newline property.
abstractmethod
¶
get_line(index)
Returns the line with the given index from the document.
This is used in rendering lines, and will be called by the TextArea for each line that is rendered.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
int
|
The index of the line in the document. |
required |
Returns:
| Type | Description |
|---|---|
str
|
The str instance representing the line. |
abstractmethod
¶
get_size(indent_width)
Get the size of the document.
The height is generally the number of lines, and the width is generally the maximum cell length of all the lines.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
int
|
The width to use for tab characters. |
required |
Returns:
| Type | Description |
|---|---|
Size
|
The Size of the document bounding box. |
abstractmethod
¶
Get the text that falls between the start and end locations.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Location
|
The start location of the selection. |
required |
|
Location
|
The end location of the selection. |
required |
Returns:
| Type | Description |
|---|---|
str
|
The text between start (inclusive) and end (exclusive). |
query_syntax_tree(query, start_point=None, end_point=None)
Query the tree-sitter syntax tree.
The default implementation always returns an empty list.
To support querying in a subclass, this must be implemented.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
'Query'
|
The tree-sitter Query to perform. |
required |
|
tuple[int, int] | None
|
The (row, column byte) to start the query at. |
None
|
|
tuple[int, int] | None
|
The (row, column byte) to end the query at. |
None
|
Returns:
| Type | Description |
|---|---|
dict[str, list['Node']]
|
A dict mapping captured node names to lists of Nodes with that name. |
abstractmethod
¶
Replace the text at the given range.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Location
|
A tuple (row, column) where the edit starts. |
required |
|
Location
|
A tuple (row, column) where the edit ends. |
required |
|
str
|
The text to insert between start and end. |
required |
Returns:
| Type | Description |
|---|---|
EditResult
|
The new end location after the edit is complete. |
DocumentNavigator(wrapped_document)
Cursor navigation in the TextArea is "wrapping-aware".
Although the cursor location (the selection) is represented as a location in the raw document, when you actually move the cursor, it must take wrapping into account (otherwise things start to look really confusing to the user where wrapping is involved).
Your cursor visually moves through the wrapped version of the document, rather than the raw document. So, for example, pressing down on the keyboard may move your cursor to a position further along the current raw document line, rather than on to the next line in the raw document.
The DocumentNavigator class manages that behavior.
Given a cursor location in the unwrapped document, and a cursor movement action, this class can inform us of the destination the cursor will move to considering the current wrapping width and document content. It can also translate between document-space (a location/(row,col) in the raw document), and visual-space (x and y offsets) as the user will see them on screen after the document has been wrapped.
For this to work correctly, the wrapped_document and document must be synchronised. This means that if you make an edit to the document, you must then update the wrapped document, and then you may query the document navigator.
Naming conventions:
A "location" refers to a location, in document-space (in the raw document). It is entirely unrelated to visually positioning. A location in a document can appear in any visual position, as it is influenced by scrolling, wrapping, gutter settings, and the cell width of characters to its left.
A "wrapped section" refers to a portion of the line accounting for wrapping. For example the line "ABCDEF" when wrapped at width 3 will result in 2 sections: "ABC" and "DEF". In this case, we call "ABC" is the first section/wrapped section.
A "wrap offset" is an integer representing the index at which wrapping occurs in a document-space line. This is a codepoint index, rather than a visual offset. In "ABCDEF" with wrapping at width 3, there is a single wrap offset of 3.
"Smart home" refers to a modification of the "home" key behavior. If smart home is enabled, the first non-whitespace character is considered to be the home location. If the cursor is currently at this position, then the normal home behavior applies. This is designed to make cursor movement more useful to end users.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
WrappedDocument
|
The WrappedDocument to be used when making navigation decisions. |
required |
instance-attribute
¶
Remembers the last x offset (cell width) the cursor was moved horizontally to, so that it can be restored on vertical movement where possible.
get_location_at_y_offset(location, vertical_offset)
Apply a visual vertical offset to a location and check the resulting location.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Location
|
The location to start from. |
required |
|
int
|
The vertical offset to move (negative=up, positive=down). |
required |
Returns:
| Type | Description |
|---|---|
Location
|
The location after the offset has been applied. |
get_location_below(location)
Given a location in the raw document, return the raw document location corresponding to moving down in the wrapped representation of the document.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Location
|
The location in the raw document. |
required |
Returns:
| Type | Description |
|---|---|
Location
|
The location which is visually below the given location. |
get_location_home(location, smart_home=False)
Get the "home location" corresponding to the given location.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Location
|
The location to consider. |
required |
|
bool
|
Enable/disable 'smart home' behavior. |
False
|
Returns:
| Type | Description |
|---|---|
Location
|
The home location, relative to the given location. |
get_location_left(location)
Get the location to the left of the given location.
Note that if the given location is at the start of the line, then this will return the end of the preceding line, since that's where you would expect the cursor to move.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Location
|
The location to start from. |
required |
Returns:
| Type | Description |
|---|---|
Location
|
The location to the right. |
get_location_right(location)
Get the location to the right of the given location.
Note that if the given location is at the end of the line, then this will return the start of the following line, since that's where you would expect the cursor to move.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Location
|
The location to start from. |
required |
Returns:
| Type | Description |
|---|---|
Location
|
The location to the right. |
is_end_of_document_line(location)
True if the location is at the end of a line in the document.
Note that the "end" of a line is equal to its length (one greater than the final index), since there is a space at the end of the line for the cursor to rest.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Location
|
The location to examine. |
required |
Returns:
| Type | Description |
|---|---|
bool
|
True if and only if the document is at the end of a line in the document. |
is_first_wrapped_line(location)
Check if the given location is on the first wrapped section of the first line in the document.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Location
|
The location to examine. |
required |
Returns:
| Type | Description |
|---|---|
bool
|
True if and only if the cursor is on the first wrapped section of the first line. |
is_last_wrapped_line(location)
Check if the given location is on the last wrapped section of the last line.
That is, the cursor is visually on the last rendered row.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Location
|
The location to examine. |
required |
Returns:
| Type | Description |
|---|---|
bool
|
True if and only if the cursor is on the last section of the last line. |
dataclass
¶
Implements the Undoable protocol to replace text at some range within a document.
property
¶
The Location impacted by this edit that is nearest the end of the document.
instance-attribute
¶
If True, the selection will maintain its offset to the replacement range.
after(text_area)
Hook for running code after an Edit has been performed via Edit.do and
side effects such as re-wrapping the document and refreshing the display
have completed.
For example, we can't record cursor visual offset until we know where the cursor will land after wrapping has been performed, so we must wait until here to do it.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
TextArea
|
The |
required |
do(text_area, record_selection=True)
Perform the edit operation.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
TextArea
|
The |
required |
|
bool
|
If True, record the current selection in the TextArea so that it may be restored if this Edit is undone in the future. |
True
|
Returns:
| Type | Description |
|---|---|
EditResult
|
An |
undo(text_area)
Undo the edit operation.
Looks at the data stored in the edit, and performs the inverse operation of Edit.do.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
TextArea
|
The |
required |
Returns:
| Type | Description |
|---|---|
EditResult
|
An |
dataclass
¶
Manages batching/checkpointing of Edits into groups that can be undone/redone in the TextArea.
instance-attribute
¶
Maximum number of characters that can appear in a batch before a new batch is formed.
instance-attribute
¶
Maximum number of seconds since last edit until a new batch is created.
record(edit)
Record an Edit so that it may be undone and redone.
Determines whether to batch the Edit with previous Edits, or create a new batch/checkpoint.
This method must be called exactly once per edit, in chronological order.
A new batch/checkpoint is created when:
- The undo stack is empty.
- The checkpoint timer expires.
- The maximum number of characters permitted in a checkpoint is reached.
- A redo is performed (we should not add new edits to a batch that has been redone).
- The programmer has requested a new batch via a call to
force_new_batch.- e.g. the TextArea widget may call this method in some circumstances.
- Clicking to move the cursor elsewhere in the document should create a new batch.
- Movement of the cursor via a keyboard action that is NOT an edit.
- Blurring the TextArea creates a new checkpoint.
- The current edit involves a deletion/replacement and the previous edit did not.
- The current edit is a pure insertion and the previous edit was not.
- The edit involves insertion or deletion of one or more newline characters.
- An edit which inserts more than a single character (a paste) gets an isolated batch.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Edit
|
The edit to record. |
required |
dataclass
¶
Bases: Exception
Raised when the user tries to use a language which does not exist. This means a language which is not builtin, or has not been registered.
Bases: NamedTuple
A range of characters within a document from a start point to the end point.
The location of the cursor is always considered to be the end point of the selection.
The selection is inclusive of the minimum point and exclusive of the maximum point.
class-attribute
instance-attribute
¶
The end location of the selection.
If you were to click and drag a selection inside a text-editor, this is where you finished dragging.
class-attribute
instance-attribute
¶
The start location of the selection.
If you were to click and drag a selection inside a text-editor, this is where you started dragging.
Bases: Document
A subclass of Document which also maintains a tree-sitter syntax tree when the document is edited.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
str
|
The initial text contained in the document. |
required |
|
Language
|
The tree-sitter language to use. |
required |
query_syntax_tree(query, start_point=None, end_point=None)
Query the tree-sitter syntax tree.
The default implementation always returns an empty list.
To support querying in a subclass, this must be implemented.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Query
|
The tree-sitter Query to perform. |
required |
|
tuple[int, int] | None
|
The (row, column byte) to start the query at. |
None
|
|
tuple[int, int] | None
|
The (row, column byte) to end the query at. |
None
|
Returns:
| Type | Description |
|---|---|
dict[str, list['Node']]
|
A tuple containing the nodes and text captured by the query. |
Replace text at the given range.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Location
|
A tuple (row, column) where the edit starts. |
required |
|
Location
|
A tuple (row, column) where the edit ends. |
required |
|
str
|
The text to insert between start and end. |
required |
Returns:
| Type | Description |
|---|---|
EditResult
|
The new end location after the edit is complete. |
dataclass
¶
TextAreaTheme(
name,
base_style=None,
gutter_style=None,
cursor_style=None,
cursor_line_style=None,
cursor_line_gutter_style=None,
bracket_matching_style=None,
selection_style=None,
syntax_styles=dict(),
)
A theme for the TextArea widget.
Allows theming the general widget (gutter, selections, cursor, and so on) and mapping of tree-sitter tokens to Rich styles.
For example, consider the following snippet from the markdown.scm highlight
query file. We've assigned the heading_content token type to the name heading.
Now, we can map this heading name to a Rich style, and it will be styled as
such in the TextArea, assuming a parser which returns a heading_content
node is used (as will be the case when language="markdown").
We can register this theme with our TextArea using the TextArea.register_theme method,
and headings in our markdown files will be styled bold cyan.
class-attribute
instance-attribute
¶
The background style of the text area. If None the parent style will be used.
class-attribute
instance-attribute
¶
The style to apply to matching brackets. If None, a legible Style will be generated.
class-attribute
instance-attribute
¶
The style to apply to the gutter of the line the cursor is on. If None, a legible Style will be
generated.
class-attribute
instance-attribute
¶
The style to apply to the line the cursor is on.
class-attribute
instance-attribute
¶
The style of the cursor. If None, a legible Style will be generated.
class-attribute
instance-attribute
¶
The style of the gutter. If None, a legible Style will be generated.
class-attribute
instance-attribute
¶
The style of the selection. If None a default selection Style will be generated.
class-attribute
instance-attribute
¶
The mapping of tree-sitter names from the highlight_query to Rich styles.
apply_css(text_area)
Apply CSS rules from a TextArea to be used for fallback styling.
If any attributes in the theme aren't supplied, they'll be filled with the appropriate base CSS (e.g. color, background, etc.) and component CSS (e.g. text-area--cursor) from the supplied TextArea.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
TextArea
|
The TextArea instance to retrieve fallback styling from. |
required |
classmethod
¶
Get a list of all builtin TextAreaThemes.
Returns:
| Type | Description |
|---|---|
list[TextAreaTheme]
|
A list of all builtin TextAreaThemes. |
classmethod
¶
get_builtin_theme(theme_name)
Get a TextAreaTheme by name.
Given a theme_name, return the corresponding TextAreaTheme object.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
str
|
The name of the theme. |
required |
Returns:
| Type | Description |
|---|---|
TextAreaTheme | None
|
The |
Bases: Exception
Raised when the user tries to use a theme which does not exist. This means a theme which is not builtin, or has not been registered.
A view into a Document which wraps the document at a certain width and can be queried to retrieve lines from the wrapped version of the document.
Allows for incremental updates, ensuring that we only re-wrap ranges of the document that were influenced by edits.
By default, a WrappedDocument is wrapped with width=0 (no wrapping). To wrap the document, use the wrap() method.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
DocumentBase
|
The document to wrap. |
required |
|
int
|
The width to wrap at. |
0
|
|
int
|
The maximum width to consider for tab characters. |
4
|
property
¶
The lines of the wrapped version of the Document.
Each index in the returned list represents a line index in the raw document. The list[str] at each index is the content of the raw document line split into multiple lines via wrapping.
Note that this is expensive to compute and is not cached.
Returns:
| Type | Description |
|---|---|
list[list[str]]
|
A list of lines from the wrapped version of the document. |
property
¶
True if the content is wrapped. This is not the same as wrapping being "enabled". For example, an empty document can have wrapping enabled, but no wrapping has actually occurred.
In other words, this is True if the length of any line in the document is greater than the available width.
get_offsets(line_index)
Given a line index, get the offsets within that line where wrapping should occur for the current document.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
int
|
The index of the line within the document. |
required |
Raises:
| Type | Description |
|---|---|
ValueError
|
When |
Returns:
| Type | Description |
|---|---|
list[int]
|
The offsets within the line where wrapping should occur. |
get_sections(line_index)
Return the sections for the given line index.
When wrapping is enabled, a single line in the document can visually span multiple lines. The list returned represents that visually (each string in the list represents a single section (y-offset) after wrapping happens).
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
int
|
The index of the line to get sections for. |
required |
Returns:
| Type | Description |
|---|---|
list[str]
|
The wrapped line as a list of strings. |
get_tab_widths(line_index)
get_target_document_column(line_index, x_offset, y_offset)
Given a line index and the offsets within the wrapped version of that line, return the corresponding column index in the raw document.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
int
|
The index of the line in the document. |
required |
|
int
|
The x-offset within the wrapped line. |
required |
|
int
|
The y-offset within the wrapped line (supports negative indexing). |
required |
Returns:
| Type | Description |
|---|---|
int
|
The column index corresponding to the line index and y offset. |
location_to_offset(location)
Convert a location in the document to an offset within the wrapped/visual display of the document.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Location
|
The location in the document. |
required |
Returns:
| Type | Description |
|---|---|
Offset
|
The Offset in the document's visual display corresponding to the given location. |
offset_to_location(offset)
Given an offset within the wrapped/visual display of the document, return the corresponding location in the document.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Offset
|
The y-offset within the document. |
required |
Raises:
| Type | Description |
|---|---|
ValueError
|
When the given offset does not correspond to a line in the document. |
Returns:
| Type | Description |
|---|---|
Location
|
The Location in the document corresponding to the given offset. |
Incrementally recompute wrapping based on a performed edit.
This must be called after the source document has been edited.
Parameters:
| Name | Type | Description | Default |
|---|---|---|---|
|
Location
|
The start location of the edit that was performed in document-space. |
required |
|
Location
|
The old end location of the edit in document-space. |
required |
|
Location
|
The new end location of the edit in document-space. |
required |